JP3312164B2 - Vacuum suction device - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a vacuum transfer device used for a pattern transfer device, a drawing device, various process manufacturing devices, an inspection and length measuring device, and a processing device such as grinding, polishing and cutting in an LSI manufacturing device. In particular, it relates to the vacuum adsorber.

[0002]

2. Description of the Related Art Conventionally, this kind of vacuum suction device used in LSI manufacturing is provided with a vacuum suction device as shown in FIGS. 5 (a) and 5 (b). This is briefly described as follows.
Is a vacuum suction device, and a sample 6 such as a wafer
A vacuum suction unit 3 having a large number of minute protrusions 2 for sucking is provided, and a land portion 4 including an annular protrusion is provided outside the vacuum suction unit 3. The land portion 4 has the same height as the projections 2, and a high-precision plane is formed by finishing the upper surface. Similarly, the upper surface of the projection 2 is also finished to form a highly accurate plane. Further, inside the vacuum adsorber 1, four vacuum exhaust holes 5 are formed, one end of which is open on the bottom surface 3a of the vacuum adsorber 3, and the other end is open on the lower surface 1a of the vacuum adsorber 1. The opening is connected to a vacuum pump (not shown).

In such a structure, after the sample 6 is placed on the upper surface of the vacuum adsorber 1 and the air under the sample 6 is evacuated from the evacuation hole 5 by operating the vacuum pump, the vacuum adsorber 3 Due to the negative pressure, the sample 6 is adsorbed on the protrusion 2 and the land 4. The upper surface of the land portion 4 forms the same plane as the upper surface of the projection 2, and the inner surface of the land portion 4, that is, the vacuum suction portion 3 is vacuum-sealed when the lower surface of the outer peripheral edge of the sample 6 is in close contact. The sample 6 is vacuum-adsorbed and follows the upper surface of the protrusion 2 and the land portion 4 which have been finished with high precision, so that warpage and bending are corrected.

[0004]

In the above-described vacuum suction device of the conventional vacuum suction device, the sample 6 is sucked on the protrusion 2 of the vacuum suction portion 3 and the upper surface of the land portion 4 by evacuation. The warpage and deformation of the sample 6 can be corrected to make the sample 6 flat. Further, since the contact area between the vacuum adsorber 1 and the sample 6 can be extremely reduced by the projections 2, the flatness is hardly reduced by dust or the like. In this case, if the structure is such that the sample 6 is simply supported by the projection 2 alone, a sufficient degree of vacuum cannot be obtained for the vacuum suction unit 3 to communicate with the outside and suck the sample 6, and external air or processing The liquid is sucked, and contaminates the sample 6 and the vacuum adsorber. Therefore, conventionally, a land portion 4 is provided to vacuum seal the vacuum suction portion 3. In order to sufficiently perform vacuum sealing, it is necessary to increase the width of the land portion 4. However, as the width increases, the probability that dust or the like adheres to the land portion 4 increases. There was a problem that the part could not be corrected to a highly accurate flat surface.

The present invention has been made in view of the above-mentioned conventional problems, and an object of the present invention is to allow a sample to be surely adsorbed irrespective of a support by only a protrusion, and to be used in a sample outer peripheral portion. Another object of the present invention is to provide a vacuum suction device that can correct a sample to a high flat surface without being affected by dust or the like.

[0006]

In order to achieve the above object, the present invention provides a method in which a sample is supported only by a large number of protrusions having the same thickness on the same upper surface and connected to a vacuum pump inside. A vacuum suction device provided with a vacuum suction device provided with a vacuum exhaust hole, wherein a vacuum suction portion formed by a concave portion communicating with the vacuum exhaust hole on the upper surface of the vacuum suction device; and A first hydrostatic seal formed by the surrounding annular protrusion, an annular groove surrounding the first static pressure seal, and a second static pressure formed by the annular protrusion surrounding the annular groove And a seal part,
A positive pressure supply hole having one end communicating with the annular groove and the other end opened to a side surface of the vacuum suction device and connected to a positive pressure supply means is provided inside the vacuum suction device, and the first and second holes are provided. the projections of the static pressure seal portion as small gap is formed between the first by setting extremely shorter than projections of the vacuum suction portion, and the upper surface of the second static pressure seal portion and the sample , The second
Characterized in that the static pressure seal portion is lower than the first static pressure seal portion . Further, the present invention is a vacuum suction device provided with a vacuum suction device that supports a sample only by a large number of protrusions whose upper surfaces are on the same plane and has a vacuum exhaust hole connected to a vacuum pump inside. A vacuum suction portion on the upper surface of the vacuum suction device, a vacuum exhaust groove surrounding the vacuum suction portion and communicating with the vacuum exhaust hole, and an annular second groove formed on the same plane as the vacuum suction portion and surrounding the vacuum exhaust groove . 1 static pressure seal portion, an annular groove surrounding the first static pressure seal portion, and an annular second groove forming the same plane as the vacuum suction portion and the first static pressure seal portion and surrounding the annular groove. A static pressure seal portion is provided, and a positive pressure supply hole communicating with the annular groove is provided inside the vacuum suction device.

[0007]

In the present invention, since the sample is supported only by the projection having an extremely small contact surface, there is almost no influence on the flatness due to dust or the like. In the present invention, two static pressure seal portions are provided outside the vacuum suction portion to form a minute gap between the sample and the sample, and positive pressure air is supplied to the annular groove. By doing so, the minute gap between the static pressure seal part and the sample at the time of vacuum evacuation has a large resistance, so the amount of air sucked into the vacuum suction part is extremely small, and the vacuum suction part can be evacuated. , Adsorb the sample. On the other hand, the supply of the positive pressure air causes the static pressure seal portion to be in a positive pressure state, so that the intrusion of dust and machining fluid from the outside is prevented. A part of this positive pressure air flows into the vacuum suction part, but since the minute gap provided between the static pressure seal part and the sample has a large resistance, the amount of positive pressure air flowing into the vacuum suction part is small, It does not affect the vacuum adsorption of the sample. Further, when a seal member is provided in the annular groove, and the seal member is brought into close contact with the sample during vacuum suction and supply of positive pressure air, the vacuum suction portion is vacuum-sealed, so that external air and processing liquid enter. Nothing.

[0008]

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS Hereinafter, the present invention will be described in detail based on embodiments shown in the drawings. FIGS. 1A and 1B are a plan view and an enlarged cross-sectional view of a main part of a first embodiment of a vacuum suction device constituting a vacuum suction device according to the present invention. In the drawings, the same components as those described in the section of the related art are denoted by the same reference numerals, and detailed description thereof will be omitted. In FIG. 1, a vacuum suction device 1 formed in a thick disk shape in this embodiment has a vacuum suction formed by a circular concave portion having a large number of small protrusions 2 indicated by small squares in the center of the upper surface. A portion 3 is provided, on the outside of which a plurality of minute protrusions 1 are also provided.
First and second static pressure seal portions 13 and 14 each formed of an annular protrusion having respective 1 and 12 are protruded concentrically. Further, in the present embodiment, these two static pressure seal portions 13 and 14 are used.
An annular groove 15 forming a positive pressure portion is provided between the vacuum suction device 1
Is formed with a vacuum exhaust hole 5 and a positive pressure supply hole 17 inside. The depth D of the vacuum suction part 3, in other words, the height of the projection 2 is about 100 μm to 1 mm. The height of the first static pressure seal portion 13 and the height of the second static pressure seal portion 14 (the height from the bottom surface 3a of the vacuum suction portion 3) are equal to each other and slightly smaller than the depth D of the vacuum suction portion 3 by (100). (About 1/10 to 1/10) small. The vacuum suction part 3 and each of the projections 2, 11, 12 of the first and second hydrostatic seal parts 13, 14 are formed into pins having the same thickness, and the upper surface thereof is finished to a highly accurate flat surface. And form the same plane. 1st, 2nd
The height d of the protrusions 11 and 12 of the static pressure seal portions 13 and 14 is several μm to 50 μm or less, and is considerably shorter than the height D of the protrusion 2 of the vacuum suction portion 3. Therefore, minute gaps 23 and 24 are formed between the first and second static pressure seal portions 13 and 14 and the sample 6, respectively. And these rams 2,11,
Numeral 12 has an appropriate cross-sectional shape such as a circle or a square, and is formed as thin as possible in order to reduce the contact area with the sample 6.
Are provided at intervals that do not cause bending.
In addition, ceramics, iron, titanium, or the like is used as a material of the protrusions 2, 11, and 12, and a ceramic, a quenched metal, or the like is used as a material of the vacuum adsorber 1.

One end of the vacuum evacuation hole 5 opens to the bottom surface 3a of the vacuum suction part 3, and the other end opens to the side surface of the vacuum suction device 1 and is connected to a vacuum pump (not shown). One end of the positive pressure supply hole 17 opens to the outer peripheral wall of the annular groove 15 and the other end opens to the side surface of the vacuum adsorber 1 and is connected to positive pressure supply means such as a compressor (not shown).

In such a structure, when the air in the evacuation hole 5 is exhausted by a vacuum pump (not shown), the air flows in the direction shown by the arrow 21 and the inside of the vacuum suction part 3 becomes a negative pressure. Therefore, the sample 6 is moved by the pressure
It is pressed against the upper surfaces of 11 and 12 to correct warpage and bending. At this time, the first static pressure seal portion 13 has a small gap 23 formed between the first static pressure seal portion 13 and the back surface of the sample 6 by setting the upper surface thereof slightly lower than the upper surface of the projection 11, and thus the vacuum suction is performed. The amount of air flowing into the section 3 is extremely small, the vacuum suction section 3 can be evacuated, and the sample 6 can be suctioned. Next, the positive pressure air 22 is supplied to the annular groove 15 through the positive pressure supply hole 17 by the operation of the positive pressure supply means such as a compressor, and the annular groove 15 and the first and second static pressure seal portions 13 and 14 are positively charged. Pressurize. Then, the positive pressure air 22 is discharged to the outside of the vacuum suction unit 3 and the vacuum suction unit 1 through the minute gap 24 between the sample 6 and the first and second static pressure seal portions 13 and 14. At this time, since the first static pressure seal portion 13 has a large resistance to the positive pressure air, the amount of the positive pressure air 22 flowing into the vacuum suction portion 3 is extremely small. Therefore, the vacuum suction of the sample 6 is not affected. Further, the second hydrostatic seal portion 14
The positive pressure air discharged to the outside removes dust adhering to the outer peripheral portion of the back surface of the sample 6, and removes the vacuum adsorber 1 during processing.
Prevents machining fluid and dust from entering inside. Therefore, contamination of the back surface of the sample 6 and the vacuum suction surface of the vacuum suction device 1, that is, the upper surfaces of the projections 2, 11, and 12 can be prevented.

As an example, when a sample 6 thicker than 500 μm is adsorbed, if the interval between the protrusions 2, 11, 12 is 1 mm and the size of the protrusions 2, 11, 12 is 0.2 mm on each side, The bending of the sample 6 is hardly observed, and the contact ratio between the back surface of the sample 6 and the upper surfaces of the projections 2, 11, and 12 is as extremely small as 4%. Therefore, the influence of dust is small over the entire surface of the sample 6 to be attracted, and high flatness can be obtained.
Further, since the protrusions 2, 11, and 12 are formed in a pin shape, adhesion of dust and the like is small.

FIGS. 2 (a) and 2 (b) are a plan view and an enlarged sectional view of a main part of a vacuum suction device showing a second embodiment of the present invention. In the vacuum suction device 1 of this embodiment, the center of the upper surface of the vacuum suction device 1 is a circular vacuum suction portion 3, an annular vacuum exhaust groove 30 is provided outside the vacuum suction portion 3, and an annular first static pressure seal is provided. The portion 13, the annular groove 15, and the second hydrostatic seal portion 14 are provided concentrically. In addition, a large number of minute projections 2, 11, 12 each having a circular cross-section are projected from the vacuum suction section 3 and the first and second hydrostatic seal sections 13, 14. Vacuum exhaust hole 5 inside
And positive pressure supply holes 17 are formed. Vacuum suction part 3
And the protrusions 2, 1 of the first and second hydrostatic seal portions 13, 14.
The surfaces on which the projections 1 and 12 are provided form the same plane. In addition, the protrusions 2, 11, and 12 have a height d of, for example, several μm.
m to 50 μm are all the same, and the upper surface forms the same plane. For this reason, the sample 6 and the vacuum suction part 3, the first and the second
Very small gaps are formed between the static pressure seal portions 13 and 14, respectively. One end of the evacuation hole 5 is connected to the evacuation groove 30, and the other end is opened on a side surface of the vacuum adsorber 1 and is connected to a pump (not shown). The evacuation groove 30 is provided instead of forming a large number of evacuation holes 5 in order to improve the rise of vacuum.

Even in such a structure, the contact ratio between the back surface of the sample 6 and the projections 2, 11, and 12 is extremely small. Therefore, the influence of dust on the entire surface of the sample 6 to be attracted is small, and high flatness can be obtained. Can be Further, since the first static pressure seal portion 13 is provided outside the vacuum suction portion 3 to form a minute gap with the sample 6, dust and the like do not flow into the vacuum suction portion 3 during vacuum suction. In addition, the amount of the positive pressure air 22 flowing into the vacuum suction unit 3 during the supply of the positive pressure air can be reduced. Therefore, the sample 6 can be reliably vacuum-adsorbed. Further, since the second static pressure seal portion 14 is provided outside the annular groove 15 and a minute gap is formed between the second static pressure seal portion 14 and the sample 6, the second static pressure seal portion 14 can be brought into a positive pressure state. It is possible to reliably prevent the machining liquid and dust from entering.

FIG. 3 is an enlarged sectional view of a main part of a vacuum suction device showing a third embodiment of the present invention. The vacuum suction device 1 in this embodiment is different from the second embodiment in the first embodiment shown in FIG.
The height of the static pressure seal portion 14 is set slightly lower than that of the first static pressure seal portion 13, and the minute gap 24 between the sample 6 and the second static pressure seal portion 14 is formed between the sample 6 and the first static pressure seal portion. This is set to be larger than the minute gap 23 between the portions 13. Other configurations are the same.

In such a structure, after the air in the vacuum suction hole 5 is evacuated and the sample 6 is evacuated, the positive pressure air 22 is supplied from the positive pressure supply hole 17 to the annular groove 15. At this time, the differential pressure between the vacuum suction part 3 and the annular groove 15 is
The positive pressure air 22 tends to flow into the vacuum suction unit 3 because the pressure difference between the atmospheric pressure outside the second static pressure seal part 14 and the annular groove 15 is larger than the pressure difference between the annular groove 15. Is a minute gap 24 between the second hydrostatic seal portion 14 and the sample 6.
Is set to be larger than the minute gap 23 between the sample 6 and the first static pressure sealing portion 13, so that the second static pressure sealing portion 14
Of the positive pressure air 22 is discharged to the outside of the vacuum adsorber 1 through the minute gap 24. Therefore, even in such a structure, the vacuum suction part 3 can be reliably vacuum-sealed, and the processing liquid is externally supplied to the minute gap 2.
4 can be prevented.

FIG. 4 is an enlarged sectional view of a main part of a vacuum suction device showing a fourth embodiment of the present invention. The vacuum suction device 1 in this embodiment is different from the annular groove 15 of the first embodiment shown in FIG.
A ring 32 provided with two seal members 33 is fitted into the
The vacuum suction part 3 is vacuum-sealed by these seal members 33.

The ring 32 is detachably fitted along the inner peripheral wall of the annular groove 15. The radially outer halves of the upper and lower surfaces of the ring 32 are formed one step lower than the inner halves over the entire circumference, thereby forming annular steps 37 and 38, respectively. Each seal member 33 is formed of a very thin (10
A ring-shaped sheet is fixed to the upper and lower surfaces of the ring 32 over the entire circumference. The outer half of the seal member 33 is not fixed to the ring 32, and the step portion 3
It extends above and below 7, 38, respectively. The upper seal member 33 adheres tightly to the back surface of the sample 6 at the time of evacuation and supply of positive pressure air, thereby vacuum-sealing the vacuum suction unit 3. The lower sealing member 33 seals the gap between the inner peripheral wall of the annular groove 15 and the ring 32 by being pressed against the inner bottom surface of the annular groove 15 when the positive pressure air 22 is supplied. The steps 37 and 38 provide a gap between the sealing member 33 and the positive-pressure air 22
Makes it easier to work. The upper step portion 37 prevents the upper sheet member 33 from sagging when not in use, and the lower step portion 38 reduces upward deformation of the lower sheet member 33 during evacuation.

In such a structure, a sample 6 such as a wafer is placed on the vacuum adsorber 1 and the vacuum exhaust hole 5 is evacuated by a vacuum pump.
2 is adsorbed. Therefore, the sample 6 has the protrusions 2 and 1
According to the upper surfaces of the first and the second, the warpage and the bending are corrected. At this time, the upper seal member 33 is sucked upward as shown in the figure and closely adheres to the back surface of the sample 6 to vacuum seal the vacuum suction part 3.

Next, when the positive pressure air 22 is supplied to the annular groove 15 from the positive pressure supply hole 17, the first and second static pressure seal portions 1 are supplied.
3 and 14 have a large resistance to the positive pressure air 22, so that the annular groove 15 is in a positive pressure state, and the upper seal member 3
3 is pressed against the back surface of the sample 6, and the lower seal member 33 is pressed against the inner bottom surface of the annular groove 15. Therefore, the vacuum suction part 3 is completely vacuum-sealed. In this state, if the working fluid is flowed and the sample 6 is worked, the working fluid enters the second static pressure seal part 14, the annular groove 15, the first static pressure seal part 13, and the vacuum suction part 3. Can be prevented. Therefore, similarly to the first and second embodiments described above, it is possible to prevent the back surface of the sample 6 and the vacuum suction surface of the vacuum suction device 1 from being contaminated.

Further, such a structure is effective in adsorbing the sample 6 which has warped largely upward. That is, in the case of the sample 6 which is largely warped upward, the outer peripheral portion of the back surface does not come into contact with the protrusion 12 and a large gap is formed between the sample 6 and the second hydrostatic seal portion 14. Even if the air in the hole 5 is exhausted, the degree of vacuum of the vacuum suction part 3 does not increase, but the ring 32 and the sealing member 33
Is provided, the outer peripheral end of the upper seal member 33 is lifted upward and adheres to the back surface of the sample 6 to close the vacuum suction unit 3. Therefore, the degree of vacuum of the vacuum suction unit 3 is increased, and the sample 6 is suctioned. Further, when the positive pressure air 22 is supplied to the annular groove 15, the upper seal member 33 is pressed against the back surface of the sample 6, thereby closing the vacuum suction section 3 accurately. On the other hand, the lower seal member 33 is configured such that the positive-pressure air 22
5 is pressed against the inner bottom surface of the annular groove 15 to seal the gap between the inner peripheral wall of the annular groove 15 and the ring 32.

In this embodiment, since the ring 32 is provided in the annular groove 15 so as to be detachable along the inner peripheral wall thereof, the present invention is applied only when the largely warped sample 6 is vacuum-adsorbed. If it can be removed. Therefore, deterioration of the seal member 33 can be prevented, and the seal member 33 can be used for a long time.

In each of the first to fourth embodiments described above, the projections 2, 11, and 12 are formed as minute pins, but the invention is not limited thereto. May be a child. Further, in all of the first to fourth embodiments, the vacuum suction portion 3 is formed in a circular shape, but may be formed in a rectangular shape or an elliptical shape. Further, in the fourth embodiment shown in FIG. 4, an example is shown in which the seal members 33 are fixed to the upper and lower surfaces of the ring 32, respectively. it can.

[0023]

As described above, in the vacuum suction apparatus according to the present invention, the sample is supported only by a number of protrusions having the same thickness on the upper surface and connected to the vacuum pump. What is claimed is: 1. A vacuum suction device comprising a vacuum suction device provided with a vacuum exhaust hole, comprising: a vacuum suction portion formed on a top surface of the vacuum suction device by a concave portion communicating with the vacuum exhaust hole; and a ring surrounding the vacuum suction portion. , A first hydrostatic seal portion formed by the projections, an annular groove surrounding the first hydrostatic seal portion, and a second hydrostatic seal portion formed by the annular protrusion surrounding the annular groove A positive pressure supply hole having one end communicating with the annular groove and the other end opened to a side surface of the vacuum adsorber and connected to positive pressure supply means inside the vacuum adsorber; And the protrusion of the second static pressure seal portion is By setting the length to be extremely shorter than that of the sample, a minute gap is formed between the upper surfaces of the first and second hydrostatic seal portions and the sample. Since it is not necessary to provide a land portion to be supported and only the protrusion is used, the contact area between the sample and the vacuum adsorber can be reduced. Therefore, the influence of dust is small, and a high flat surface can be obtained by correcting the warpage or bending of the sample. In addition, since the first and second static pressure seal portions are in a positive pressure state during processing, dust and processing liquid do not enter from outside.

Further, in the present invention, since the vacuum suction portion is formed by the concave portion, the vacuum pressure distribution in the vacuum exhaust portion becomes uniform, and the sample can be suctioned satisfactorily.

Also, the present invention provides a vacuum suction part and first and second
Since the static pressure seal portion is formed on the same plane, the vacuum suction device can be easily formed.

Further, according to the present invention, a vacuum evacuation groove is formed between the vacuum suction part and the first static pressure seal part in the vacuum adsorber, and a vacuum evacuation hole is connected to this groove. Can be improved, and the sample can be vacuum-adsorbed in a short time.

Further, according to the present invention, an annular groove is provided between the first and second static pressure seal portions, and a ring provided with an annular seal member is disposed in the annular groove. Since the seal member is brought into close contact with the back surface of the sample at the time of supply, the vacuum suction portion can be reliably vacuum-sealed at the time of vacuum suction and at the time of supply of positive pressure air. Further, when such a seal member is used, the degree of vacuum of the vacuum suction part can be increased when a sample that is greatly warped upward is sucked, and the sample can be reliably sucked by vacuum.

Further, according to the present invention, the second static pressure seal portion is set lower than the first static pressure seal portion, and the resistance of the second static pressure seal portion to positive pressure air is reduced by the first static pressure seal portion. , The positive pressure air can be discharged to the outside of the vacuum adsorber through the minute gap between the sample and the second static pressure seal portion, and the air flowing into the first static pressure seal portion can be discharged. The amount can be reduced.

[Brief description of the drawings]

FIGS. 1 (a) and 1 (b) are a plan view and an enlarged sectional view of a main part showing a first embodiment of a vacuum suction device constituting a vacuum suction device according to the present invention.

FIGS. 2A and 2B are a plan view and an enlarged sectional view of a main part of a vacuum suction device showing a second embodiment of the present invention.

FIG. 3 is an enlarged sectional view of a main part of a vacuum suction device showing a third embodiment of the present invention.

FIG. 4 is an enlarged sectional view of a main part of a vacuum suction device showing a fourth embodiment of the present invention.

FIGS. 5A and 5B are a plan view and an enlarged sectional view of a main part of a conventional vacuum suction device.

[Explanation of symbols]

DESCRIPTION OF SYMBOLS 1 ... Vacuum adsorber, 2 ... Projection, 3 ... Vacuum adsorption part, 4 ... Land part, 5 ... Vacuum exhaust hole, 6 ... Sample, 11, 12 ... Projection,
13: first static pressure seal portion, 14: second static pressure seal portion, 15: annular groove, 17: positive pressure supply hole, 22: positive pressure air, 23, 24: minute gap, 30: vacuum exhaust groove , 31 ...
Static pressure seal part, 32 ... ring, 33 ... seal member, 35
... minute gaps, 37, 38 ... steps.

──────────────────────────────────────────────────続 き Continuation of front page (56) References JP-A-63-226939 (JP, A) JP-A-62-221130 (JP, A) JP-A-62-24639 (JP, A) JP-A-63-22639 141670 (JP, A) JP-A-5-326677 (JP, A) JP-A-5-235151 (JP, A) Japanese Utility Model Application No. Sho 59-187147 (JP, U) Japanese Utility Model Application No. Sho 59-36245 (JP, U) Japanese Utility Model Showa 60-130647 (JP, U) Japanese Utility Model Showa 58-18341 (JP, U) Japanese Utility Model Showa 62-100835 (JP, U) Japanese Utility Model Utility Model 7-31245 (JP, U) (58) (Int.Cl. ⁷ , DB name) H01L 21/68 H01L 21/301 H01L 21/304 H01L 21/027 H01L 21/46

Claims (2)

(57) [Claims] 1. A vacuum provided with a vacuum adsorber which supports a sample only by a number of protrusions having the same thickness and having the same upper surface and having a vacuum exhaust hole connected to a vacuum pump inside. A suction device, comprising: a vacuum suction portion formed by a concave portion in which the vacuum exhaust hole communicates with an upper surface of the vacuum suction device; and a first static pressure seal formed by an annular protrusion surrounding the vacuum suction portion. An annular groove surrounding the first hydrostatic seal portion, and a second hydrostatic seal portion formed by an annular protrusion surrounding the annular groove,
A positive pressure supply hole having one end communicating with the annular groove and the other end opened to a side surface of the vacuum suction device and connected to a positive pressure supply means is provided inside the vacuum suction device, and the first and second holes are provided. the projections of the static pressure seal portion as small gap is formed between the first by setting extremely shorter than projections of the vacuum suction portion, and the upper surface of the second static pressure seal portion and the sample , The second
The vacuum suction device according to claim 1, wherein the static pressure seal portion is lower than the first static pressure seal portion . 2. A vacuum suction device comprising a vacuum suction device provided with a vacuum evacuation hole for supporting a sample only by a large number of projections having an upper surface on the same plane, and having a vacuum pumping hole connected to a vacuum pump therein. Forming a vacuum suction portion on the upper surface of the vacuum suction device, a vacuum exhaust groove surrounding the vacuum suction portion and communicating with the vacuum exhaust hole, and forming the vacuum exhaust portion on the same plane as the vacuum suction portion;
An annular first static pressure sealing portion surrounding the groove, an annular groove surrounding the first static pressure sealing portion, and an annular groove forming the same plane as the vacuum suction portion and the first static pressure sealing portion; A vacuum suction device, comprising: an annular second static pressure seal portion surrounding the positive pressure supply hole communicating with the annular groove inside the vacuum suction device.