KR101190121B1 - Structural member having a plurality of conductive regions - Google Patents

Abstract

In a structure having a plurality of conductive regions electrically insulated from each other, the plurality of conductive regions are electrically insulated from each other by successive oxidation regions, and the oxide regions are formed of a material having a plurality of through holes or grooves. It is formed of an oxide.

Microstructure, Conductive, Through Hole, Groove, Oxide

Description

A structure having a plurality of conductive regions {STRUCTURAL MEMBER HAVING A PLURALITY OF CONDUCTIVE REGIONS}

The present invention relates to a structure having a plurality of conductive regions, such as a microstructure having a plurality of regions electrically insulated from each other, and a manufacturing method thereof. The invention also relates to devices such as acceleration sensors, gyroscopes, potential sensors, and actuators using such structures.

Conventionally, as a conventional microstructure manufactured by the technique of MEMS (micro-electro-mechanical systems) or the like, the structure and the movable body are electrically connected to each other so as to detect driving, control, displacement, etc. using an electrical signal. There is a structure which is divided into a plurality of regions insulated by a metal and used as an electrode. By using such a configuration, an actuator having a plurality of driving force generating mechanisms, a sensor having a plurality of electrostatic detection units, and the like can be easily realized. Hereinafter, specific examples will be described.

A semiconductor acceleration switch having a structure in which an insulator is provided between a plurality of movable electrodes and used as a beam portion is disclosed in Japanese Patent Laid-Open No. 2000-065855. 13 is a perspective view of an acceleration switch described in Japanese Laid-Open Patent Publication No. 2000-065855. In Fig. 13, the acceleration switch includes a support substrate 901, a fixed portion 902, a movable portion 903, a fixed electrode 905, a control electrode 906, and stoppers 907a and 907b. In addition, the acceleration switch includes the support part 908, the beams 909, 991 and 992, the mass body 910, the movable electrodes 911 and 913, the frame part 916, the insulating film 917, the movable part main body 930 and the terminal 981. And 982, an electrode 961. In such a configuration, an insulating film 917 is disposed between the movable electrodes 911 and 913 to form a beam 909. The beams 909 hold the mass 910 to which the input acceleration is applied. Since the plurality of movable electrodes 911 and 913 included in the beam 909 are insulated from each other, the sensor characteristics are controlled between the movable electrode 911 and the fixed electrode 902, so that the acceleration can be detected between the movable electrode 913 and the fixed electrode 905. In the configuration described in Japanese Patent Laid-Open No. 2000-065855, an insulating film 917 such as spin-on-glass (SOG), thermal oxide film, polysilicon, or the like is formed in the deep narrow grooves formed in the silicon substrate.

Further, a semiconductor dynamic quantity sensor having a structure in which an insulating film is embedded in a support portion of a beam and a support portion of an electrostatic bladder and insulated from other portions is described in Japanese Patent Laid-Open No. 2000-286430. have. 14 is a perspective view of a semiconductor dynamic amount sensor disclosed in Japanese Laid-Open Patent Publication No. 2000-286430. As shown in Fig. 14, the semiconductor dynamic quantity sensor includes a single crystal silicon substrate 1, grooves 4a to 4d, a square frame portion 5, beam structure 6, anchor portions 7 and 8, beam portion 9 and 10, the mass portion 11, the movable electrodes 12a-12d, the movable electrodes 13a-13d, the grooves 14a, 14b, and the insulating materials 15a-15d. In addition, the semiconductor dynamic quantity sensor includes the first fixed electrodes 16a to 16d, the second fixed electrodes 17a to 17d, the grooves 18a to 18d, the insulating materials 19a to 19d, the grooves 20a to 20d, the insulating materials 21a to 21d, and the first fixed electrodes 16a to 16d. The fixed electrodes 22a to 22d, the second fixed electrodes 23a to 23d, the grooves 24a to 24d, the insulating materials 25a to 25d, the grooves 26a to 26d and the insulating materials 27a to 27d are included.

The beams 9 and 10 supporting the mass portion 11 are held by the rectangular frame portion 5 via the insulating materials 15a to 15d. Meanwhile. The first fixed electrodes 16a to 16d, 22a to 22d, and the second fixed electrodes 17a to 17d, 23a to 23d are formed by the rectangular frame portion (27a to 19d, 21a to 21d, 25a to 25d, and 27a to 27d). Held by 5). With this configuration, the rectangular frame portion 5, the mass portion 11 including the movable electrodes 12a-12d and 13a-13d, the first fixed electrode and the second fixed electrode are electrically insulated from each other. And mechanically maintained. Therefore, the mass part 11 moves by the dynamic amount of a measurement object. The amount of operation can be detected by detecting the capacitance between the first fixed electrode and the first movable electrode and the capacitance between the second fixed electrode and the second movable electrode.

Japanese Laid-Open Patent Publication No. 2000-286430 mentions forming a silicon oxide film inside the formed groove, and further forming a polysilicon film to fill the groove. This document describes that by using low stress polysilicon in combination, there is an effect of reducing stress generated in the grooves, as compared with the case where the grooves are filled with only the silicon oxide film alone.

 In the above conventional configuration, an insulating material is arranged between a plurality of regions electrically insulated from each other, and the plurality of regions are held together. Therefore, the positional relationship between the plurality of regions is easily affected by the internal stress of the insulating material. In addition, since the thermal expansion coefficients of the insulating material and the substrate member into which the insulating material is inserted are different from each other, stress is likely to occur between the substrate member and the insulating material. Therefore, the structure is also susceptible to changes in stress between materials due to changes in environmental temperature. In addition, when high voltage is applied, it is necessary to thicken the insulating material in order to increase the dielectric breakdown voltage. However, the thicker the insulating material is, the more the structure is susceptible to the stress caused by the difference in the internal stress of the insulating material and the thermal expansion coefficient between the materials.

In addition, the above-described configuration can be realized by forming a through hole or a groove in the substrate member and embedding the insulating material in the groove or the through hole. However, the embedded insulating film may be difficult to be uniform. In addition, in order to fill the insulating film, it may be necessary to widen the width of the groove and the through hole. In this case, such a structure is likely to be affected by the stress of the embedded insulating material. In addition, depending on the depth position of the through-hole and the groove, the formation state of the formed insulating material changes, and there is a possibility that stress distribution occurs. On the other hand, there are methods for embedding various kinds of insulating materials including low stress insulating materials in through holes or grooves. However, in this method, the width of the through hole may need to be widened, or the manufacturing process may be complicated.

When the above stress is generated in the microstructure, the beam and the mass itself deform, and the mechanical characteristics change, so that the drive characteristics of the actuator and the detection sensitivity characteristics of the sensor fluctuate. In addition, the distance between electrodes may change due to deformation of the beam, the mass itself, and the comb teeth electrode. Thereby, there exists a possibility that the driving force applied to a microstructure may greatly deviate from what you want, and the measurement precision of the movable amount of a microstructure may fall. As a result, these cause the deterioration of the drive performance of the actuator and the detection performance of the sensor.

In view of the above problem, the present invention provides a structure having a plurality of conductive regions electrically insulated from each other, wherein the plurality of conductive regions are electrically insulated from each other by successive oxidation regions; The oxide regions are each formed of an oxide made of a material having a plurality of through holes or grooves.

In addition, in view of the above problem, the present invention provides a method of manufacturing a structure having a plurality of conductive regions electrically insulated from each other, and the manufacturing method includes the following two steps. In the first step, a plurality of through holes or grooves are formed in the base material so as to be spaced apart. In the second step, the plurality of electrically insulated from each other by thermally oxidizing the base material of at least the inner surface of the plurality of through holes or grooves to form continuous oxidation regions including the plurality of through holes or grooves. Conductive regions are formed in the base material.

In addition, in view of the above problem, the present invention provides an acceleration sensor including a structure, and the structure includes a movable body for sensing acceleration. In addition, in view of the above problem, the present invention provides a gyroscope including a structure, the structure includes a movable body for sensing the angular velocity.

In addition, in view of the above problem, the present invention provides an actuator including a structure, the structure including a movable body for converting the force of the input electrical energy into physical motion. The present invention also provides a potential sensor including a structure, wherein the structure includes a movable body having a detection electrode portion for outputting an electrical signal in accordance with the potential of the measurement target.

As described above, in the structure according to the present invention, a plurality of conductive regions are insulated from each other by successively formed oxide regions, which are formed of an oxide of a material in which a plurality of through holes or grooves are formed. Is done. Therefore, the oxidized regions forming the insulation can be reduced to a relatively small amount, and a structure having a plurality of electrically insulated regions which are hard to generate stress in the oxidized regions can be provided in a simple configuration. In addition, in the method for producing the structure, thermal oxidation is performed on at least a base material constituting the inner surface of the plurality of through holes or grooves, so that continuous oxidation regions are formed, thereby facilitating manufacture thereof. In addition, when forming the oxidation regions, the substrate forming the structure does not need to be physically separated by etching or cutting. For this reason, an insulation process is attained, without seriously compromising the board | substrate strength and processing precision. Moreover, in the device using the structure of the present invention where stress is hard to occur, the performance such as its detection sensitivity and driving characteristics can be improved.

1 is a perspective view of an actuator according to a first embodiment of the present invention.

2A, 2B, and 2C are views for explaining an insulating portion of an oxidized region according to the first embodiment of the present invention.

3A and 3A are cross-sectional views illustrating a manufacturing process of an actuator according to a first embodiment of the present invention.

3B (a) and 3B (b) are cross-sectional views for explaining a manufacturing process of an actuator according to a first embodiment of the present invention.

3C and 3C are cross-sectional views illustrating a manufacturing process of an actuator according to a first embodiment of the present invention.

3D and 3D are cross-sectional views for explaining a manufacturing process of an actuator according to a first embodiment of the present invention.

3E (a) and 3E (b) are cross-sectional views for explaining a manufacturing process of an actuator according to a first embodiment of the present invention.

4A, 4B, and 4C are diagrams for explaining a thermal oxidation process at the time of manufacturing the actuator according to the first embodiment of the present invention.

5A is a cross-sectional view illustrating a manufacturing process of an actuator according to a second embodiment of the present invention.

5B and 5B are cross-sectional views illustrating a manufacturing process of an actuator according to a second embodiment of the present invention.

5C and 5C are cross-sectional views illustrating a manufacturing process of an actuator according to a second embodiment of the present invention.

5D and 5D are cross-sectional views for explaining a manufacturing process of an actuator according to a second embodiment of the present invention.

5E (a) and 5E (b) are cross-sectional views for explaining a manufacturing process of an actuator according to a second embodiment of the present invention.

6A is a cross-sectional view for describing a manufacturing process of an actuator according to a third embodiment of the present disclosure.

6B (a) and 6B (b) are cross-sectional views illustrating a manufacturing process of an actuator according to a third embodiment of the present invention.

6C and 6C are cross-sectional views illustrating a manufacturing process of an actuator according to a third embodiment of the present invention.

6D and 6D are cross-sectional views for explaining a manufacturing process of an actuator according to a third embodiment of the present invention.

6E (a) and 6E (b) are cross-sectional views for explaining a manufacturing process of an actuator according to a third embodiment of the present invention.

6F (a) and 6F (b) are cross-sectional views illustrating a manufacturing process of an actuator according to a third embodiment of the present invention.

6G and 6G are cross-sectional views illustrating a manufacturing process of an actuator according to a third embodiment of the present invention.

6H (a) and 6H (b) are cross-sectional views illustrating a manufacturing process of an actuator according to a third embodiment of the present invention.

7a (a), 7a (b), 7a (c), 7a (d), 7a (e), 7a (f), and 7a (g) show through holes in accordance with a fourth embodiment of the present invention. It is a top view explaining various examples of a cross-sectional shape and arrangement, and a sectional view of the through hole according to the fifth embodiment of the present invention.

7B (a) and 7B (b) are cross-sectional views for describing the structure according to the fifth embodiment of the present invention.

8 is a perspective view of a feedback type acceleration sensor according to a seventh embodiment of the present invention.

9 is a perspective view of a frame type gyroscope according to an eighth embodiment of the present invention.

10 is a perspective view of another form of a frame-type gyroscope according to a ninth embodiment of the present invention.

11 is a perspective view of an optical scanner according to a tenth embodiment of the present invention.

12 is a perspective view of a potential sensor according to an eleventh embodiment of the present disclosure.

It is a perspective view of the acceleration switch of Unexamined-Japanese-Patent No. 2000-065855.

14 is a perspective view of a semiconductor dynamics sensor described in Japanese Laid-Open Patent Publication No. 2000-286430.

(Best mode for practicing the present invention)

EMBODIMENT OF THE INVENTION Hereinafter, the Example of this invention is described in detail using drawing.

(First Embodiment)

A first embodiment of the present invention will be described with reference to Figs. 1, 2A, 2B, 2C, 3A (a) to 3E (b), 4A, 4B and 4C. A first embodiment of the present invention is directed to an actuator (mechanism for converting a force of input electrical energy into physical motion) and a method of manufacturing the actuator, including a structure having a plurality of conductive regions electrically insulated from each other. It is about. 1 is a perspective view of an actuator according to a first embodiment of the present invention. As shown in Fig. 1, the actuator includes a substrate 101 made of conductive silicon, a movable body 102, a beam 103, a thermal oxide film 104 (oxidized region), a through hole 105, and a first movable member. An electrode 106, a second movable electrode 107, a first fixed electrode 108, and a second fixed electrode 109 are included.

The substrate 101 is a base material on which the movable body 102, the beam 103, the fixed electrodes 108, 109, and the like are formed. The through holes 105 are formed in the thermal oxide film (oxidation region) 104, respectively. In this way, the thermal oxide film 104 constitutes a continuous oxidation region. In this configuration, no path from one conductive region having the thermal oxide film 104 interposed therebetween reaches the other conductive region without passing through the portion of the thermal oxide film 104. That is, since the junction region between the plurality of conductive regions can be completely occupied by the thermal oxide film 104 of the oxidized region, the plurality of conductive regions having the thermal oxide film 104 interposed therebetween are electrically insulated from each other. The thermal oxide film 104 is formed of an oxide made of a material (the base material) on which the plurality of through holes 105 are formed. In addition, the first movable electrode 106 and the first fixed electrode 108 have comb teeth that face each other at intervals. Similarly, the second movable electrode 107 and the second fixed electrode 109 also have blazing portions facing each other.

In the above configuration, the first movable electrode 106, the second movable electrode 107, the first fixed electrode 108, and the second fixed electrode 109 are formed by the thermal oxide film 104. It is electrically insulated from each other. It is a feature of the actuator according to the first embodiment of the present invention that the thermal oxide film 104 has a plurality of through holes 105. According to the formation pattern of the thermal oxide film 104 shown in FIG. 1, the first movable electrode 106 passes through the beam 103 and is left of the substrate 101 except for the first fixed electrode 108. -half) is electrically connected to the part (left electrode). The second movable electrode 107 is electrically connected to the right-half portion (right electrode) of the substrate 101 except for the second fixed electrode 109 via the beam 103.

2A, 2B, and 2C show an enlarged view of a portion of the thermal oxide film 104 having the through hole 105. FIG. 2A is a plan view of the substrate, FIG. 2B is a sectional view of the substrate on straight lines B1-B2, and FIG. 2C is a sectional view of the substrate on straight lines C1-C2. As shown in FIGS. 2A, 2B, and 2C, the substrate has a first region 111 and a second region 112. The first region 111 and the second region 112 are used as various regions depending on the position of the thermal oxide film 104.

2A, 2B, and 2C, the thermal oxide film 104 is formed continuously in order to electrically isolate the first region 111 and the second region 112 from each other. Therefore, between the 1st area | region 111 and the 2nd area | region 112 can electrically insulate completely from each other. In this case, since the thermal oxide film 104 has a plurality of through holes 105, the volume of the insulating material (thermal oxide film) connecting the first region 111 and the second region 112 or The thickness can be kept to the minimum that requires mechanical strength. As a result, a microstructure having a structure in which deformation of the movable body 102 and the substrate 101 is less likely to occur due to the influence of the stress of the thermal oxide film, as compared with the above-described conventional structure in which an insulating film having no through hole is formed. It can be realized.

In the configuration of FIG. 1, the movable body 102 is supported by the substrate 101 by two pairs of beams 103 to move in the directions indicated by arrows A1 and A2. The movable body 102 is composed of a thermally oxidized film 104 having a first movable electrode 106, a second movable electrode 107, and a plurality of through holes 105. On the other hand, the substrate 101 includes a thermal oxide film 104 having a first fixed electrode 108, a second fixed electrode 109, a plurality of through holes 105, a left electrode, and a right electrode. It consists of. In addition, the wiring for connecting each of the first movable electrode 106 and the second movable electrode 107 to the control circuit connects each of the left and right electrodes of the substrate 101 to the bonding wire from the outside. It can be done via the beam 103 by wiring. The wiring for connecting each of the first fixed electrode 108 and the second fixed electrode 109 to the control circuit connects each of the first fixed electrode 108 and the second fixed electrode 109 to the outside. Wiring by bonding wires or the like, or forming wirings for connecting each of the first fixed electrode 108 and the second fixed electrode 109 on an insulating film formed at a suitable place on the substrate 101. Can be.

The first movable electrode 106, the second movable electrode 107, the first fixed electrode 108, and the second fixed electrode 109 are electrically insulated from each other. Therefore, any different potential can be applied to each electrode. Therefore, when a potential difference is applied between the first movable electrode 106 and the first fixed electrode 108, an electrostatic attraction is generated between the first movable electrode 106 and the first fixed electrode 108. Thus, the movable body 102 can be moved in the direction indicated by the arrow A1. Similarly, when a potential difference is applied between the second movable electrode 107 and the second fixed electrode 109, an electrostatic attraction occurs between the second movable electrode 107 and the second fixed electrode 109, thereby operating The sieve 102 can be moved in the direction indicated by arrow A2. The application of the potential difference between the first movable electrode 106 and the first fixed electrode 108 and the application of the potential difference between the second movable electrode 107 and the second fixed electrode 109 alternately. By virtue of this, the movable body 102 can be vibrated at a desired cycle.

In the configuration of the first embodiment of the present invention, the positional relationship between the movable electrodes 106, 107 and the fixed electrodes 108, 109 for generating the electrostatic attraction is hardly changed due to the stress. Therefore, uniform electrostatic attraction can be applied to the actuator in the whole actuator. Moreover, the influence of the external force applied to the beam 103 for supporting a movable body by each deformation | transformation of the movable body 102 and the board | substrate 101 can be suppressed. As a result, the mechanical characteristics of the actuator are less likely to change. For the reason mentioned above, the actuator which performs a higher precision drive can be implement | achieved.

Next, a manufacturing method of the actuator according to the first embodiment of the present invention will be described. The method comprises the steps of forming a plurality of through holes in the base material at intervals and thermally oxidizing at least the base material on the inner surface of the plurality of through holes to form a continuous oxidized region including a plurality of through holes. And forming a plurality of conductive regions electrically insulated from each other on the base material. 3A (a) to 3E (b) are cross-sectional views for explaining a manufacturing process of the actuator according to the first embodiment of the present invention. 3A (a) to 3E (b), each of FIGS. 3A (a), 3B (a), 3c (a), 3d (a), and 3e (a) is taken along the broken line P of FIG. The cross section of a part is shown, and FIG. 3A (b), 3b (b), 3c (b), 3d (b), and 3e (b) show the cross section of the part along the broken line Q of FIG. However, in FIG. 3A (a), 3B (a), 3c (a), 3d (a), and 3e (a), in order to make it easy to see, the number of through holes formed in the part corresponding to the movable body 102 is shown. The formation of the oxidized region of the portion corresponding to the substrate 101 is omitted. 3A (a) to 3E (b), reference numeral 201 denotes silicon as a base material on which a substrate, a movable body, or the like is formed, reference numeral 202 denotes a resist, reference numeral 203 denotes a mask material, and reference numeral 204 denotes The thermal oxide film, 210 is a through hole in the oxidized region.

First, as shown in FIGS. 3A and 3A, the mask material 203 is deposited on one side of the silicon substrate 201, the resist 202 is applied, and then the resist 202 is formed in an arbitrary pattern. Pattern). Then, the mask material 203 is selectively etched and removed using the remaining resist pattern. The part obtained by removing this mask material corresponds to the part which forms the through hole which consists of silicon by the next dry etching process. Specifically, the removal of the portion corresponding to the through hole 210 of the oxidized region and the removal of unnecessary portions for forming the structure (moving body, beam, movable electrode, fixed electrode, and supporting substrate) at the same time Do it. In this case, as the mask material 203, a material such as Al (aluminum), silicon nitride, silicon oxide, polysilicon, or the like can be used. However, the mask material is not limited thereto, and any material can be used as long as it is a material that can withstand when used as a mask material in the next anisotropic etching step. In addition, the pattern of the resist 202 may be removed and may be used as a mask of the next dry etching process. In this case, deposition and etching of another mask material are not essential.

Next, as shown in Figs. 3B (a) and 3B (b), anisotropic etching is performed on the substrate surface on which the mask material 203 is formed from a portion without a mask, and the through hole 210 is formed in the substrate 201. To form. In this case, as the anisotropic etching, dry etching such as Si Deep-RIE can be used.

After the anisotropic etching, as shown in Figs. 3C (a) and 3C (b), the mask material 203, the resist 202, and the like are removed to clean the surface of the silicon substrate 201.

Then, thermal oxidation is performed on the silicon surface as shown in Figs. 3D (a) and 3d (b). In the thermal oxidation step, the silicon oxide is grown in the exposed silicon by leaving the silicon in an oxygen atmosphere of 1000 ° C. or more for a long time. This silicon oxide not only grows on the silicon surface but also grows inside the surface while increasing each oxidation region from the silicon surface to the inside thereof (the ratio of the thickness of the former to the thickness of the latter is about 55:45).

Here, the process of thermal oxidation is demonstrated. 4A, 4B, and 4C are top views of the substrates for explaining how the thermal oxidation process proceeds. As shown in Figs. 4A, 4B, and 4C, the substrate includes a first region 111, a second region 112, a thermal oxide film 113 formed on the silicon surface, and a thermal oxide film 114 formed inside the silicon. First, the state of the board | substrate before oxidation is shown to FIG. 4A. At this time, since the portion between the through holes 105 is made of silicon (denoted by the width X), the first region 111 and the second region 112 are not insulated from each other.

Next, the state of the substrate after thermal oxidation for half of the predetermined time is shown in Fig. 4B. At this time, the thermal oxide film 113 grows on the surface of the through hole 105 and the thermal oxide film 114 also grows inside the silicon, and the width X of the silicon formed between the adjacent through holes 105 is narrowed. Therefore, the 1st area | region 111 and the 2nd area | region 112 are insulated slightly from each other.

Finally, the state of the board | substrate after thermal oxidation for a predetermined time is shown in FIG. 4C. At this time, the thermal oxide films 114 grown in the silicon from the adjacent through holes 105 are in contact with each other and integrated. Therefore, the 1st area | region 111 and the 2nd area | region 112 are insulated from each other.

The relationship between the thermal oxidation time and the thickness of the thermal oxide film 104 formed is a logarithmic function. That is, when sufficient oxidation time is taken, each thickness of the thermal oxide film 104 reaches a saturation of a constant value (about 1 µm to several µm). Therefore, the thickness of each thermal oxide film can be controlled with high precision. Also, considering the time for performing the actual manufacturing process, the silicon formed between the adjacent through holes 105 is completely oxidized to electrically insulate both regions of the conductive from each other, so that As for the distance (width X of FIG. 4A) which adjoins, about 2 micrometers or less are more preferable.

On the other hand, in anisotropic etching of silicon, it is more preferable that substrate thickness (depth of a through hole) is about 100 micrometers or less. That is, when the substrate thickness is about 100 µm or more, the inclination by etching to the substrate surface causes deformation of the structure that thermal stress due to the asymmetry of the shape of the thermal oxide film and silicon cannot be ignored.

As described above, a plurality of conductive regions electrically insulated from each other can be formed by these steps. In particular, after arranging the plurality of through holes 105 in close proximity to each other, a plurality of conductive regions electrically insulated from each other can be easily formed only by thermal oxidation. In addition, the formation of the plurality of through holes 105 can be performed at the same time as the step for forming the movable body 102 and the beam 103. Therefore, the structure according to the first embodiment of the present invention can be produced not only in the steps performed when producing the simple structure but also in the number of steps of silicon etching. Moreover, since it can be shared with the mask for structure manufacture, the number of masks for silicon etching does not increase.

The thermal oxide film 104 can be formed as long as oxygen is supplied even at a narrow gap. Therefore, the distance between the electrically insulated regions can be narrowed, and the influence of the stress of the insulating material (thermal oxide film) in the oxidized region can be minimized. In addition, in the first embodiment of the present invention, each material formed between adjacent through holes 105 is thermally oxidized to insulate, so that it is not necessary to fill the through holes with insulating materials as in the conventional method. Therefore, occurrence of problems such as internal stress caused by the insulating material can be suppressed.

Moreover, since an actuator can be manufactured only by a single silicon substrate, it is not necessary to use special substrates, such as an SOI substrate.

In the past, when a single silicon substrate is used without using an SOI substrate, since the silicon under the movable body is removed by etching, the thickness accuracy of the movable body cannot be greatly increased. On the other hand, in the first embodiment of the present invention, since the thickness of the movable body 102 is determined using the thickness of the silicon substrate, higher thickness precision can be realized.

Finally, after the process of FIGS. 3D (a) and 3D (b), as shown in FIGS. 3E (a) and 3E (b), dry etching from both sides of the substrate is used to The silicon oxide film formed on the surface may be removed. Accordingly, since the thermal oxide film formed on the upper and lower surfaces of the substrate is removed, the stress caused by the thermal oxide film can be further reduced. On the other hand, the thermal oxide film shown in Fig. 3E (b) is not necessary in function but is inevitably formed in the manufacturing process. There is no problem even if the thermal oxide film is left as it is.

In addition, when the width of each of the through holes 105 is small, there is a possibility that the through holes 105 are almost completely filled with the thermal oxide film 113 finally. However, the continuous oxidation region including the through hole or the groove according to the present invention also includes such a form. However, in order to suppress the occurrence of problems such as internal stress, the amount of oxide in the oxidized region should be as small as possible as long as the function of insulation is fulfilled. For this reason, the width of the through hole 105 can usually be used several times or more than the thickness of the oxide film.

(Second Embodiment)

Next, a second embodiment of the present invention will be described with reference to FIGS. 5A to 5E (b). The second embodiment differs from the first embodiment in the manufacturing process of the actuator. The other structure is almost the same as in the first embodiment.

5A to 5E (b) are cross-sectional views for explaining a manufacturing process of an actuator according to a second embodiment of the present invention. 5A to 5E (b), reference numeral 201 denotes silicon, 202 a resist, 203 a mask material, 204 a thermal oxide film, and 210 a through hole of an oxidized region. In addition, in FIGS. 5B (a) to 5E (b), the same components are defined or omitted in the same manner as in FIGS. 3A (a) to 3E (b).

In the second embodiment of the present invention, as shown in FIG. 5A, a substrate (base material) obtained by forming the mask material 203 on both surfaces of the silicon substrate 201 is used. First, the resist 202 is apply | coated on a board | substrate, and one surface is patterned in arbitrary patterns. The state of the board | substrate obtained after selectively etching the mask material 203 using this remaining resist pattern is shown to FIG. 5B (a) and 5B (b).

Next, using the mask material 203 as an etching mask, dry etching is performed on the silicon 201 to form the through hole 210. Thereafter, as shown in FIGS. 5C and 5C, the mask material 203 formed on the back surface is also etched in the same shape as the pattern of the through hole 210.

Thereafter, the resist 202 is removed to clean the substrate. Thereafter, as shown in Figs. 5E (a) and 5D (b), thermal oxidation of the silicon 201 is performed in a high temperature oxygen atmosphere. At this time, the portion where the mask material 203 is formed on both surfaces of the substrate is not thermally oxidized, and the thermal oxide film 204 is formed only on the portion of silicon exposed in the previous dry etching process.

Finally, the mask material 203 is removed by etching, as shown in FIGS. 5E (a) and 5E (b).

According to the second embodiment of the present invention, the region in which the mask material 203 is formed is not thermally oxidized. Therefore, in the thermal oxidation process shown in FIGS. 5D (a) and 5D (b) which insulate, the deformation of the structure due to the stress of the thermal oxide film is more difficult to occur.

As the mask material 203 of the second embodiment of the present invention, any material can be used as long as it can withstand the temperature in the thermal oxidation step. In particular, it is suitable to use silicon nitride. By using silicon nitride, only thermally oxidized silicon can be selectively left in the microstructure.

As the mask material 203, silicon oxide may be used. When the thickness of the silicon oxide used as the mask is thick, the thickness of the silicon oxide used as the mask hardly changes during the thermal oxidation step shown in FIGS. 5D and 5D. Therefore, the stress of the silicon oxide used as the mask material 203 hardly changes.

As described above, in the second embodiment of the present invention, in the step of forming the oxidized region, a mask material such as silicon nitride is provided in a portion other than the inner surface of each through hole of the base material before the thermal oxidation step is performed. Formed. Therefore, the manufacturing process which can form a microstructure by reducing the stress which arises on the surface of a board | substrate at the time of a thermal oxidation process can be provided.

(Third Embodiment)

Next, a third embodiment of the present invention will be described using Figs. 6A to 6H (b). The third embodiment differs from the first embodiment in the manufacturing process of the actuator. Except for the process, the third embodiment is almost the same as the first embodiment.

6A to 6H (b) are sectional views for explaining a manufacturing process of the actuator according to the third embodiment of the present invention. 6A to 6H (b), reference numeral 201 denotes silicon, 202 denotes a resist, 203 denotes a mask material, 204 denotes a thermal oxide film, 205 denotes an oxide film, 206 denotes a second silicon substrate, 207 denotes a protective film, and 210 denotes an oxidized region. Through hole. 6B (a) to 6H (b), the same components are defined or omitted in the same manner as in FIGS. 3A (a) to 3E (b).

In the third embodiment of the present invention, a silicon-on-insulator (SOI) substrate (base material) is used in which the substrate 201 and the second silicon substrate 206 are connected to each other using the oxide film 205. . 6A shows a state in which a mask material 203 is formed on both surfaces of an SOI substrate.

First, as shown in FIGS. 6B (a) and 6B (b), the mask material 203 is deposited on one side of the SOI substrate, and a resist is applied. Thereafter, the resist 202 is patterned in an arbitrary pattern. The mask material 203 is selectively etched and removed using the remaining resist pattern.

Next, as shown in FIGS. 6C and 6C, anisotropic etching is performed on the substrate surface on which the mask material 203 is formed, from the portion without the mask, so that the through hole 210 is formed in the substrate 201. ). In this case, dry etching such as Si Deep-RIE can be used as the anisotropic etching. After the anisotropic etching, the resist 202 is removed to clean the surface of the silicon substrate.

Thereafter, thermal oxidation is performed on the surface of the silicon substrate as shown in Figs. 6D (a) and 6D (b). When the silicon substrate is placed in an oxygen atmosphere of 1000 ° C. or more for a long time, silicon oxide is grown on the side surface of the silicon substrate exposed by anisotropic etching.

Next, as shown in Figs. 6E (a) and 6E (b), the protective film 207 is formed on the surface on which the anisotropic etching is performed, and the protective film (only in the region where the thermal oxide film 204 is desired to be left by patterning and etching). 207). Thereafter, as shown in Figs. 6F (a) and 6F (b), the silicon substrate 206 is etched from the rear surface thereof in an arbitrary pattern.

Next, silicon oxide is removed by etching. At this time, the exposed thermal oxide film 204 and the oxide film 205 of the SOI substrate are removed. As shown in Figs. 6G and 6G, by adjusting the etching time, only the thermal oxide film 204 in the region to be left can be left.

Finally, as shown in Figs. 6H and 6H, the protective film 207 is removed. As a result, it is possible to form a microstructure including a plurality of conductive regions electrically insulated from each other, leaving only the insulating portion formed of the thermal oxide film 204.

As described above, in the third embodiment of the present invention using the SOI substrate including the oxide film 205, only the thermal oxide film (oxidized region) necessary to electrically insulate a plurality of conductive regions from each other, the protective film 207 By using, it can be easily left in a more accurate shape. Therefore, the shape of the thermal oxide film obtained after etching reduces the influence on the mechanical properties and the electrical insulation properties of the microstructure.

(4th Example)

A fourth embodiment of the present invention will be described. The fourth embodiment differs from the above embodiment in the formation of the contour of the structure, the formation of the through hole of the insulating portion (oxidized region), and the thermal oxidation process.

First, the following method can be used. Formation of the contour of the structure portion and formation of the through hole of the insulation portion are simultaneously performed by etching. Thereafter, the contour portion of the structure may be covered with a protective material to thermally oxidize only the sidewall of the through hole. Thereby, the shape of the contour portion of the structure does not change by the step of thermal oxidation. Therefore, the microstructure with less change of a characteristic can be provided. In particular, in the electrostatic bladders that can be used for driving the movable body and detecting the displacement of the movable body, the distance between the bladders greatly influences the driving characteristics and the detection characteristics. Therefore, in the fourth embodiment of the present invention, since the effective distance between the bladders is not increased by thermal oxidation, deterioration of the drive characteristics and the detection characteristics in the bladder portion can be suppressed.

In this case, etching of only the structure part and protection with a protective material may be performed first, and after that, insulation by etching and thermal oxidation of the through-hole of the insulating part may be performed.

In addition, the following method can also be used. After only etching the through-holes of the insulating portion, the thermal oxidation step is performed to insulate. Next, the contour portion of the structure is etched again to form the structure. This increases the number of silicon etching steps, but does not increase the effective distance between the bladder portions due to thermal oxidation. Therefore, deterioration of the drive characteristic and detection characteristic in a bladder part can be suppressed. In addition, after insulating by thermal oxidation, by forming a part of the structure including the comb electrodes, it is possible to arrange the blazing electrodes more accurately than when performing the thermal oxidation after forming the blazing electrode.

(Fifth Embodiment)

In the fifth embodiment of the present invention, some examples of structures in which the shape and arrangement of the through holes are different from those in the above embodiment are shown. The rest other than the shape and arrangement of the through holes are the same as in the first embodiment of the present invention.

7a (a), 7a (b), 7a (c), 7a (d), 7a (e), 7a (f), and 7a (g) are through holes according to the fifth embodiment of the present invention. It is a figure for demonstrating the cross-sectional shape and arrangement | positioning of the. The shape of each through hole is not limited to the shape described in the first embodiment. Circle (example of 7a (a)), ellipse, rectangle (example of 7a (b)), triangle (example of 7a (c)), square, parallelogram (example of 7a (d)), and other polygons (7a It is an example of (e), and shows an octagon here), etc. can be used. In the example of FIG. 7A (c), in order to make the width | variety of the material formed in each clearance gap between holes substantially, the upper and lower sides of a triangular hole are reversed alternately. As shown in the example of Fig. 7A (f), the through holes of different shapes may be arranged in combination (in this case, the holes of the triangle and the parallelogram are alternately arranged while the direction is appropriately changed). In addition, the through holes may be arranged in a straight line, or may be arranged in a curved shape or a stepped shape. In addition, as shown in the example of Fig. 7A (g), the through holes may be arranged in a plurality of rows to shift the position of the gap between the through holes in each row (that is, the through holes are alternately staggered). May be arranged). Of course, in any of these examples, the width of the material formed in the gap between the holes must be set so that the material is oxidized reliably by the oxidation process from the respective inner surfaces of the holes formed on both sides to the intermediate point of the material so that the insulation is obtained. There is.

By appropriately selecting the shape of these holes in some cases, it is possible to provide a microstructure in which the mechanical strength of the insulating part is maintained well while reducing the influence of the stress of the thermal oxide film.

(Sixth Embodiment)

7B (a) and 7B (b) are diagrams for explaining the sixth embodiment of the present invention. 7B (a) and 7B (b) are sectional views corresponding to FIGS. 3B (a) and 3b (b) of the first embodiment. As shown in Figs. 7B (a) and 7B (b) of the sixth embodiment of the present invention, the holes may be replaced with grooves 211 that do not completely penetrate the substrate 201. In this case, the difference between the thickness of the substrate 201 and the depth of the grooves 211 (the thickness of the portion of the material under the bottom of each groove) depends on the thickness of the thermal oxide film formed inside the silicon by the thermal oxidation process. It is necessary to select an appropriate value as the difference. When thermal oxidation is performed from both surfaces of the substrate 201, it is necessary to set the difference to not more than twice the thickness of the thermal oxidation film. When thermal oxidation is performed only from one surface side of the substrate 201, it is necessary to set the difference below the thickness of the thermal oxidation film. These values are preferably set to about 2 μm or less (for the former) or about 1 μm or less (for the latter) for the reasons described in the first embodiment. In addition, it is preferable to set the depth of each groove to about 100 micrometers or less for the reason demonstrated in 1st Example. As such, the plurality of holes in the oxidized region of the structure according to the present invention may be a groove. Moreover, a through hole and a groove can also be mixed.

By using such a form, it is not necessary to necessarily use a through hole, the design constraints of the microstructures are reduced, and the strength characteristics of the microstructures are easily improved.

(Seventh embodiment)

Next, an FB (FeedBack) type acceleration sensor according to a seventh embodiment of the present invention will be described with reference to FIG. 8. The seventh embodiment differs from the above embodiment in that the structure of the present invention is used not as an actuator but as an FB type acceleration sensor.

In FIG. 8, the acceleration sensor includes a substrate 101, a movable body 102, a beam 103, a thermal oxide film 104, a through hole 105, a first movable electrode 106, and a second movable member. An electrode 107, a first fixed electrode 108, a second fixed electrode 109, a third fixed electrode 128, and a fourth fixed electrode 129 are included. First fixed electrode 108, second fixed electrode 109, first movable electrode 106, second movable electrode 107, third fixed electrode 128, and fourth fixed The electrodes 129 are insulated from each other by the method described in the above embodiments. Each electrode is electrically connected to the control circuit via the movable body 102, the beam 103, or the like. The wiring for connecting the third fixed electrode 128 and the fourth fixed electrode 129 to the control circuit is, as described above, from the outside through the bonding wire or the like from the third fixed electrode 128 and the fourth. Wiring by connecting the third fixed electrode 128 and the fourth fixed electrode 129 on the insulating film formed at a suitable position on the substrate 101. .

In the acceleration sensor according to the seventh embodiment of the present invention, the movable body 102 is held by the beams 103 connected to the substrate 101, respectively. The movable body 102 has a structure which is easy to move only in the direction shown by the arrow A. FIG. When acceleration is added to the acceleration sensor according to the seventh embodiment of the present invention in the direction indicated by the arrow A, the movable body 102 moves in either direction of the arrow A along the magnitude of the acceleration. In this case, the capacitance between the first fixed electrode 108 and the first movable electrode 106 and the capacitance between the second fixed electrode 109 and the second movable electrode 107 are movable. The sieve 102 changes with the distance traveled. At this time, when one capacitance increases, the other capacitance decreases. The capacitance increases as the distance between the electrodes becomes smaller. Therefore, it can be seen that the movable body 102 moves in the direction of the electrode pair with increased capacitance.

The acceleration sensor according to the seventh embodiment of the present invention has a unit that detects the movement of the movable body 102 and applies a force that cancels the acceleration force in the opposite direction to the acceleration force. . Specifically, a predetermined potential is applied to either the third fixed electrode 128 or the fourth fixed electrode 129. By doing this, a potential difference is generated between the third fixed electrode 128 and the first movable electrode 106 or between the fourth fixed electrode 129 and the second movable electrode 107, and a potential difference is generated. Electrostatic attraction is generated between the electrodes.

In this way, when there is a potential difference between the movable electrode and the fixed electrode opposite to the movable electrode, electrostatic attraction occurs in the electrode pair. On the other hand, if there is no potential difference between the movable electrode and the fixed electrode opposite to the movable electrode, no electrostatic attraction occurs between the electrode pairs. By using this, the acceleration sensor which concerns on 7th Example of this invention is controlled so that the force which cancels the force of the detected acceleration is always applied to the movable body 102. FIG.

In the acceleration sensor of the seventh embodiment of the present invention, since the applied acceleration is always fed back and canceled, the movable body 102 is prevented from moving excessively even when a large acceleration is applied. Thus, the movable body 102 is prevented from contacting the bladder electrode and damaging the bladder electrode. In addition, by detecting the magnitude of the force obtained when the acceleration is fed back and balanced, high-accuracy acceleration can be detected. By applying the insulating structure of this invention to the acceleration sensor of such a structure, a some movable electrode can also be formed also in the movable body 102, and more complicated detection control and more precise detection control can be achieved.

In addition, by processing the silicon substrate, the electrostatic bladder portion can be easily formed even in a thick structure. For this reason, the efficiency of the drive of a sensor and the detection by a sensor improves. In addition, the deformation of the microstructure due to the stress of the insulating portion in the oxidized region can be reduced. As a result, a higher performance acceleration sensor can be provided using the structure of the present invention including a movable body for sensing acceleration.

(Eighth Embodiment)

9, a frame type gyroscope according to an eighth embodiment of the present invention will be described. The eighth embodiment differs from the above embodiment in that the structure of the present invention is applied to a frame type gyroscope.

9 is a perspective view showing a state of the frame-type gyroscope according to the eighth embodiment of the present invention, in which the upper and lower substrates are separated from each other. 9, the gyroscope includes a substrate 101, a movable body 102, a beam 103, a thermal oxide film 104, a through hole 105, a first movable electrode 106, and a second movable electrode. 107, the first fixed electrode 108, the second fixed electrode 109, the first movable body 121, the second movable body 122, the second beam 123, and the third The movable electrode 124, the fourth movable electrode 125, the lower substrate 131, the recess 132 of the lower substrate 131, and the fixed electrodes 133 and 134 formed on the lower substrate 131. .

The frame type gyroscope has two movable bodies (movable bodies 121 and 122 in the eighth embodiment of the present invention), and each movable body is supported so as to easily generate vibrations in different directions. A gyroscope vibrates a movable body at a constant amplitude and detects displacement of the movable body (hereinafter referred to as "detection vibration") by Coriolis force generated by input of angular velocity from the outside. Can be used. The direction of vibration of the first movable body (hereinafter referred to as "reference vibration"), the axial direction for detecting the angular velocity, and the direction in which Coriolis force is generated are perpendicular to each other. In a frame type gyroscope, the movable body for generating the reference vibration and the movable body for detecting the force of Coriolis are different. Therefore, a frame type gyroscope can be easily realized by producing a mechanism that is easy to generate vibration (easy to move) in the reference vibration direction and the detection vibration direction, and which is difficult to generate vibration (difficult to move) in other directions. Can be.

Hereinafter, a frame type gyroscope according to an eighth embodiment of the present invention will be specifically described.

9, the gyroscope according to the eighth embodiment of the present invention has a structure in which the substrate 101 and the lower substrate 131 are attached together. First fixed electrode 108, second fixed electrode 109, first movable electrode 106, second movable electrode 107, third movable electrode 124, and fourth movable The electrodes 125 are insulated from each other by the method described in the above embodiments. Each electrode is electrically connected to each other via the movable body 102, the beam 103, the 2nd movable body 122, the 2nd beam 123, etc.

Using the fixed electrode 133 and the fixed electrode 134 formed on the third movable electrode 124, the fourth movable electrode 125, and the lower substrate 131, the second movable body 122 is indicated by an arrow Y. FIG. The reference vibration is generated at predetermined cycles in the direction indicated by. The first movable body 102 121 is held by the substrate 101 on the beam 103 so as to be difficult to move in a direction other than the direction indicated by the arrow X. Therefore, the first movable body 102 is maintained in a stopped state without being affected by the reference vibration of the second movable body 122.

In this case, when the angular velocity in the direction indicated by the arrow Z is applied to the gyroscope, the second movable body 122 receives the force in the direction indicated by the arrow X by the force of the generated Coriolis. However, the 2nd movable body 122 is hold | maintained by the 2nd beam 123 so that it may be hard to move to directions other than the direction shown by the arrow Y. Therefore, the force of the direction shown by the arrow X applied to the 2nd movable body 122 is transmitted to the movable body 102121 as it is. Since the movable body 102 is easily held in the direction indicated by the arrow X, the movable body 102 generates detection vibration in the direction indicated by the arrow X. FIG. At this time, the positional relationship of the direction shown by the arrow X of the movable body 102 and the 2nd movable body 122 does not change. In this case, the capacitance between the first fixed electrode 106 and the first movable electrode 108 and the capacitance between the second fixed electrode 107 and the second movable electrode 109 are detected. The magnitude of the detected vibration is detected, and the angular velocity based on the magnitude of the detected vibration is measured.

According to the eighth embodiment of the present invention, different potentials may be applied to the electrodes 124, 125, 133, and 134 for generating the reference vibration. Therefore, vibration can be generated efficiently, and a large reference vibration can be generated. Since the magnitude of the reference vibration is related to the detection sensitivity of the gyroscope, a high sensitivity gyroscope can be provided. In addition, the electrodes 106, 107, 108, and 109 for detecting the detection signal can be set to different potentials. Therefore, the carrier signal for detection can be applied, and the signal with little noise can be extracted.

In addition, since the electrostatic bladder portion can be easily formed in a thick structure by processing the silicon substrate, the efficiency of driving the sensor and detecting by the sensor is improved. In addition, the deformation of the microstructure due to the stress in the insulating portion of the oxidized region can be reduced. As a result, a higher performance gyroscope can be provided using the structure of the present invention including a movable body for sensing a force due to acceleration.

(Ninth embodiment)

10, another frame-type gyroscope according to the ninth embodiment of the present invention will be described. The ninth embodiment differs from the above embodiment in that the structure of the present invention is used for the frame type gyroscope shown in FIG.

10 shows a perspective view of a frame-type gyroscope according to a ninth embodiment of the present invention. As shown in FIG. 10, the gyroscope includes a substrate 101, a movable body 102, a beam 103, a thermal oxide film 104, a through hole 105, a first movable electrode 106, and a second one. The movable electrode 107, the first fixed electrode 108, the second fixed electrode 109, the first movable body 121, the second movable body 122, the second beam 123, The third movable electrode 124, the fourth movable electrode 125, the fifth movable electrode 126, and the sixth movable electrode 127 are included.

The frame type gyroscope according to the ninth embodiment of the present invention differs from the eighth embodiment of the present invention in the following points. That is, in the frame type gyroscope according to the ninth embodiment of the present invention, the fixed electrodes 133 and 134 formed on the lower substrate 131 are the fourth movable electrode 125 and the sixth movable electrode 127. It is arrange | positioned on the 1st movable body 121 as a.

The first fixed electrode 108, the second fixed electrode 109, the fourth movable electrode 125, and the sixth movable electrode 127 are formed from other electrodes by the method described in the above embodiment. Each is insulated. In addition, the first movable electrode 106, the second movable electrode 107, the third movable electrode 124, and the fifth movable electrode 126 are electrically connected to each other, and the above-described implementation is performed. It is insulated from each other by the method as described in the example. Each electrode is electrically connected to each other via the movable body 102, the beam 103, the second movable body 122, the second beam 123, and the like.

Using the first movable electrode 106 and the first fixed electrode 108, and the second movable electrode 107 and the second fixed electrode 109, the first movable body 102 121 is formed. , Generate or generate a reference vibration in a predetermined period in the direction indicated by the arrow X. The second movable body 122 is held by the second beam 123 so as not to move in a direction other than the direction indicated by the arrow Y. Therefore, the second movable body 122 also generates reference vibrations in the same period in the same direction indicated by the arrow X like the first movable body 102.

In this case, when the angular velocity in the direction indicated by the arrow Z is applied to the gyroscope, the first movable body 102 and the second movable body 122 are forced in the direction indicated by the arrow Y by the generated Coriolis force. Receives. However, the 1st movable body 102 is hold | maintained by the 1st beam 103 so that it may be hard to move to directions other than the direction shown by the arrow X. FIG. Therefore, only the second movable body 122 moves in the direction indicated by the arrow Y to generate the detection vibration. In this case, the capacitance between the third movable electrode 124 and the fourth movable electrode 125 and the capacitance between the fifth movable electrode 126 and the sixth movable electrode 127 are detected by detecting the capacitance. The magnitude of the detected vibration is detected, and the angular velocity based on the magnitude of the detected vibration is measured.

In the frame-type gyroscope according to the ninth embodiment of the present invention, the positional relationship between the first movable body 102 and the second movable body 122 does not change in reference vibration. In addition, the detection vibration is detected by detecting the relative position between the first movable body 102 and the second movable body 122. For the same reason as described above, in the frame type gyroscope according to the ninth embodiment of the present invention, even when the reference vibration has wobbling in a direction other than the direction indicated by the arrow X, Noise is less likely to occur in the detection signal.

The third movable electrode 124 and the fourth movable electrode 125, and the fifth movable electrode 124, which are used for detecting the detection vibration by using the insulating method using the oxidized region according to the ninth embodiment of the present invention. The movable electrode 126 and the sixth movable electrode 127 can be easily disposed on the movable body 102. In addition, a symmetrical structure can be obtained with respect to the thickness direction of the substrate, and the wobbling of the reference vibration can be reduced. For the same reason as described above, by applying the structure including the insulating portion of the oxidized region according to the present invention to the frame type gyroscope, a more precise gyroscope can be provided.

In the frame-type gyroscope, the direction of the reference vibration, the direction of the detection vibration, and which of the movable bodies generate the detection vibration are not limited to those of the above-described configuration. The structure according to the present invention can be applied to other configurations for detecting an angular velocity in other combinations thereof.

(Tenth Embodiment)

An optical scanner according to a tenth embodiment of the present invention will be described with reference to FIG. 11. The tenth embodiment differs from the above embodiment in that the structure of the present invention is applied to the optical scanner shown in FIG.

11 is a perspective view of an optical scanner according to a tenth embodiment of the present invention. As shown in Fig. 11, the optical scanner in which the upper and lower substrates are separated from each other includes a movable beam 801 having an optical deflection element such as a mirror, support beams 802 such as a torsion spring, and the like. The insulating portion 803 of the oxidized region, the first electrode portion 805, the second electrode portion 806, the upper substrate 807, the third electrode 808, the fourth electrode 809, A lower substrate 810 and a spacer 811.

The movable body 801 is supported by the support beams 802 to the upper substrate 807 so as to be rotatable in the movable direction indicated by the arrow D. FIG. The first electrode portion 805 and the second electrode portion 806 of the movable body 801 that are insulated from each other by the insulation portion 803 are similarly spaced by the spacer 811, and the insulation portion 803 is similarly formed. The fourth electrode part 809 and the third electrode part 808 which are insulated from each other and formed on the lower substrate 810 are opposed to each other. Therefore, an electric potential difference occurs alternately between the first electrode portion 805 and the fourth electrode portion 809, and between the second electrode portion 806 and the third electrode portion 808, and alternates between the electrodes. When the applied voltage is controlled so that the furnace attraction acts, the movable body 801 rotates about the axis of the support beam 802. As a result, light incident on the optical deflecting element on the movable body 801 is deflected.

By using the insulation method using the oxidized region according to the tenth embodiment of the present invention, the deformation of the structure due to the stress in the insulated portion of the oxidized region is less, and the first electrode portion 805 and the second electrode portion are reduced. 806 can be easily disposed on the rotatable movable body 801. In addition, the third electrode portion 808 and the fourth electrode portion 809 can also be easily disposed on the lower substrate 810. For the same reason as described above, by applying the structure of the present invention including the insulating portion of the oxidized region to the optical scanner, a higher performance optical scanner can be provided. On the other hand, it is sometimes necessary to arrange the oxidized region or to form a reflective film or the like on the surface of the oxidized region so that the portion of the oxidized region does not unnecessarily affect the optical properties.

(Eleventh embodiment)

12, an electromagnetic driving potential sensor according to an eleventh embodiment of the present invention will be described. The eleventh embodiment differs from the above embodiment in that the structure of the present invention is applied to the potential sensor shown in FIG.

12 is a perspective view of a potential sensor according to an eleventh embodiment of the present invention. As shown in FIG. 12, the potential sensor in the state where the upper and lower substrates are separated from each other includes the movable beam 801, the support beams 802 such as a torsion spring, the insulator 803 of the above-described oxidation region, and the movable body 801. Magnet 804 having an N pole and an S pole fixed to the rear surface of the (), the first detection electrode portion 805, the second detection electrode portion 806, the upper substrate 807, the lower substrate 810, A spacer 811, a coil 812, and a lead-out electrode 813.

In the eleventh embodiment of the present invention, the movable body 801 is held by the torsion spring 802, and the torsion spring 802 is fixed to the upper substrate 807. As shown in FIG. 12, the movable body 801, the torsion spring 802, and the upper substrate 807 are formed of the first detection electrode portion 805 and the second insulated with each other by the insulation portion 803. It is divided into the detection electrode part 806. On the lower substrate 810, a coil 812 is disposed to face the first detection electrode portion 805 and the second detection electrode portion 806 at appropriate intervals with the spacer 811.

By applying an AC drive signal to the coil 812, the movable body 801 is applied to the movable body 801 according to the relationship between the direction of the magnetic field of the magnet 804 and the direction of the current flowing through the coil 812 (the law of the left hand of Fleming). Generate mechanical vibrations. The movable body 801 generates torsional vibration in the direction indicated by the arrow D. FIG.

In the eleventh embodiment of the present invention, the potential measurement is performed as follows. The object to be measured, such as a charged photosensitive member, is positioned in proximity to the first and second detection electrode portions 805 and 806, and mechanically vibrates the movable object 801 to mechanically measure the object and the measurement electrodes. To change the capacity of the unit. As a result, the electric potential of the measurement target is measured by detecting the small change in electric charge induced in the electrostatic induction furnace detection electrodes 805 and 806 through the current signal. In this case, the signals from the detection electrode portions 805 and 806 change out of phase. Therefore, by differentially processing these signals, it is possible to provide a potential sensor with a high removal ratio of in-phase noise.

By using the electromagnetic actuator of such a structure, large vibration can be obtained efficiently. In addition, by using the insulation method using the oxidized region according to the eleventh embodiment of the present invention, deformation of the structure due to stress in the insulated portion of the oxidized region is reduced, and the first detection electrode portion 805 and the second are reduced. Can be easily disposed on the rotatable movable body 801. Therefore, a detection signal having a larger charge that is stable in a compact structure can be obtained. In this way, in the potential sensor according to the eleventh embodiment of the present invention, the structure of the present invention including a movable body each having a detection electrode portion for outputting an electric signal corresponding to the potential of the measurement target is used. A high-precision potential sensor having a configuration can be realized.

In the above description, the acceleration sensor, gyroscope, optical scanner, and potential sensor have been described, but the application range of the structure according to the present invention is not limited thereto. The present invention can be used for these devices as long as a structure having a plurality of conductive regions electrically insulated from each other to devices other than a semiconductor sensor or the like is applicable.

In addition, as shown in the above embodiment, the application of the present invention is not limited to the arrangement of the insulator in the acceleration sensor, the gyroscope, etc., the combination of the electrodes, the method of dividing the region, and the wiring method. The present invention can be applied to any configuration as long as it can provide a function necessary for an actuator, a sensor, or the like, and has a mechanical strength necessary for a structure such as a microstructure, and can limit deformation caused by stress of the structure within specifications.

In the above embodiment, silicon is used as the substrate as the base material. However, any material other than silicon can be used as long as the oxide has insulation and can form through holes or grooves from the material. In addition, etching was used in the said Example as a method of forming a through-hole and a groove. However, in consideration of the thickness and material of the base material, the size of the through hole and the groove, etc., the through hole and the groove may be formed by laser processing or the like.

This application claims priority from Japanese Patent Laid-Open No. 2007-009657, filed Jan. 19, 2007, the entire contents of which are incorporated herein by reference.

Claims (10)

A structure having a substrate comprising a plurality of conductive regions electrically insulated from each other, The plurality of conductive regions are electrically insulated from each other by successive oxidation regions, And the oxidized regions are formed of a plurality of through holes or grooves, and a thermal oxide of the substrate formed around the plurality of through holes or grooves. The method of claim 1, The closest distance between the plurality of through holes or grooves is 2 μm or less. The method of claim 1, A difference between a thickness of a portion of the material in which each of the grooves is formed and a depth of each of the grooves, corresponding to the thickness of the material present under each bottom of the grooves, is 2 μm or less. The method of claim 1, The through holes or grooves have a depth of less than 100㎛. A method of manufacturing a structure having a plurality of conductive regions electrically insulated from each other, Forming a plurality of through holes or grooves in the substrate at intervals from each other in an area for oxidizing the substrate, A continuous oxidation region comprising thermally oxidizing the substrate on at least the inner surface of the plurality of through holes or grooves and a thermal oxide film formed around the plurality of through holes or grooves Forming the plurality of electrically conductive regions electrically insulated from each other by forming them in the substrate. 6. The method of claim 5, Forming the oxide regions comprises forming silicon nitride in a portion other than the inner surface of the through holes or grooves of the substrate prior to thermally oxidizing the substrate. An acceleration sensor having a structure according to claim 1, wherein the structure comprises a movable body for sensing acceleration. A gyroscope having a structure according to claim 1, wherein the structure comprises a movable body for sensing a force due to angular velocity. An actuator comprising a structure according to claim 1, wherein the structure comprises a movable body for converting a force of input electrical energy into physical motion. A potential sensor having a structure according to claim 1, wherein the structure comprises a movable body having a detection electrode portion for outputting an electrical signal according to the potential of a measurement target.

Images