JP2017066434A - Film forming apparatus and laminate - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a technology for stably producing a laminate of a desired color at high accuracy by a film deposition process.SOLUTION: A laminate having a transparent layer and a metallic opaque layer viewed from one side is produced by a film deposition process on the surface of a substrate. In a film deposition apparatus, a decision section decides film deposition conditions based on color information provided by an input section referring to corresponding data. The film deposition conditions include at least film thickness of the transparent layer as a factor to adjust the color of the laminate. When the laminate is irradiated with light from the one side, reflected light from the surface of the transparent layer interferes with reflected light from the surface of the opaque layer. The interference is altered by adjusting the film thickness of the transparent layer and thus the color of the laminate is adjusted. Therefore, the laminate of a desired color is stably produced at high accuracy, which surpasses laminates produced in film deposition conditions adjusted by a feeling or experiences of an operator of the film deposition apparatus.SELECTED DRAWING: Figure 6

Description

  The present invention relates to a film forming apparatus for forming a film on the surface of a substrate and a laminate obtained by the film formation.

  There is known a technique for adjusting the color of a film to be obtained by adjusting film forming conditions for forming a film on the surface of a substrate. As this type of technology, for example, Patent Document 1 discloses a color tone when viewed from one side (transparent film side) by superimposing a transparent film having a specific refractive index and thickness on a polymer dye film. A technique for obtaining a laminated body in which the change appears to change is disclosed.

JP 2015-24622 A

  When it is desired to form a layered product of the color seen from one side, if there is data that has been subjected to the same color film forming process in the past, the data is referred to and the same film forming conditions as in the past process are used. By executing the film forming process, a laminate of a target color can be obtained.

  On the other hand, when it is desired to form a film of a color as viewed from the one side, if there is no data for performing the same color film formation process in the past, the film formation conditions are determined by the operator's intuition and empirical rules. Generally, the adjustment is performed.

  However, in this aspect, the influence of the error for each operator is unavoidable, and it is difficult to stably obtain a desired color laminate with high accuracy.

  Therefore, an object of the present invention is to provide a technique for stably obtaining a laminated body having a desired color with high accuracy by a film forming process.

  The film forming apparatus according to the first aspect of the present invention is a film forming apparatus for obtaining a laminate by forming at least one film on one side of the surface of a substrate, and has a processing space therein. A processing chamber, a base material holding portion for holding the base material in the processing chamber, a gas supply portion for supplying gas to the processing space, an exhaust portion for discharging the gas in the processing chamber, and the base material A film formation processing unit that performs film formation processing on the surface of the base material held by the holding unit, an input unit that receives color information when the laminate is viewed from the one side, and a plurality of colors The color information and the color information input from the input unit, the storage unit storing correspondence data in which the film formation condition for obtaining the laminate having the color viewed from the one side is obtained, and the color information input from the input unit Determining unit for determining the film forming condition with reference to the corresponding data based on The laminate has a transparent layer and a metal opaque layer in order as viewed from the one side, and the film forming conditions include at least the film thickness of the transparent layer as an element of color adjustment. It is characterized by that.

  The film forming apparatus according to the second aspect of the present invention is the film forming apparatus according to the first aspect of the present invention, and is configured to apply the irradiation light to the stacked body from the one side. A first reflected light obtained by reflecting the irradiation light on the surface on one side, and the transparent layer passing through the transparent layer of the laminate when the irradiation light is applied to the laminate from the one side; The color adjustment is realized by the action of interference with the second reflected light obtained by reflection at the interface with the metal opaque layer, and the interference action changes according to the film thickness of the transparent layer. Features.

  A film forming apparatus according to a third aspect of the present invention is the film forming apparatus according to the first aspect or the second aspect of the present invention, wherein the color information input from the input unit is the corresponding data. A determination unit that determines whether or not the image is included in a compatible range; and a notification unit that notifies an operator of the apparatus when the color information is not included in the compatible range. Features.

  A film forming apparatus according to a fourth aspect of the present invention is the film forming apparatus according to any one of the first to third aspects of the present invention, wherein the correspondence data includes each layer constituting the laminate. Each optical constant and the film thickness of the transparent layer and the color information of the laminate viewed from the one side are data associated with each other by theoretical calculation.

  A film forming apparatus according to a fifth aspect of the present invention is the film forming apparatus according to any one of the first to fourth aspects of the present invention, wherein the laminate is a decoration of a building interior or an exterior. It is used as a material.

  A film forming apparatus according to a sixth aspect of the present invention is the film forming apparatus according to any one of the first to fifth aspects of the present invention, wherein the transparent layer is a silicon nitride layer. And

  A film forming apparatus according to a seventh aspect of the present invention is the film forming apparatus according to any one of the first to fifth aspects of the present invention, wherein the transparent layer is a titanium oxide layer. And

  A film forming apparatus according to an eighth aspect of the present invention is the film forming apparatus according to any one of the first to fifth aspects of the present invention, wherein the transparent layer is an aluminum oxide layer. And

  A film forming apparatus according to a ninth aspect of the present invention is the film forming apparatus according to any one of the first to fifth aspects of the present invention, wherein the transparent layer is a titanium nitride layer. And

  The laminate according to the tenth aspect of the present invention is a laminate obtained by forming at least one film on one side of the surface of the base material, and in order from the one side, the transparent layer and And an opaque layer made of metal, and the color when the laminate is viewed from the one side is dependent on the film thickness of the transparent layer.

  The laminate according to the eleventh aspect of the present invention is the laminate according to the tenth aspect of the present invention, wherein the dependency is determined by applying the irradiation light to the laminate from the one side. The first reflected light obtained by reflecting the irradiation light on the surface of the one side of the body, and passing through the transparent layer of the laminate when the irradiation light is applied to the laminate from the one side The second reflected light obtained by reflection at the interface between the transparent layer and the metal opaque layer interferes, and the interference action changes according to the film thickness of the transparent layer. Features.

  A laminated body according to a twelfth aspect of the present invention is a laminated body according to the tenth aspect or the eleventh aspect of the present invention, and is characterized in that it is used as a decorative material for an interior or exterior of a building.

  A laminate according to a thirteenth aspect of the present invention is the laminate according to any one of the tenth to twelfth aspects of the present invention, wherein the transparent layer is a silicon nitride layer. .

  A laminate according to a fourteenth aspect of the present invention is the laminate according to any one of the tenth to twelfth aspects of the present invention, wherein the transparent layer is a titanium oxide layer. .

  A laminate according to a fifteenth aspect of the present invention is the laminate according to any one of the tenth to twelfth aspects of the present invention, wherein the transparent layer is an aluminum oxide layer. .

  A laminate according to a sixteenth aspect of the present invention is the laminate according to any one of the tenth to twelfth aspects of the present invention, wherein the transparent layer is a titanium nitride layer. .

  In the first to ninth aspects of the present invention, in the film forming apparatus, the determining unit determines the film forming condition with reference to the corresponding data based on the color information input from the input unit. In addition, the film forming conditions include at least the film thickness of the transparent layer as an element for color adjustment. For this reason, in the first aspect of the present invention, film formation processing of a desired color can be performed with high accuracy and stability, compared to an aspect in which film formation conditions are adjusted based on the intuition and rule of thumb of the film formation apparatus operator. It is feasible.

It is a cross-sectional schematic diagram which shows typically schematic structure of a sputtering device. It is a cross-sectional schematic diagram which shows a sputter processing part and its periphery. It is a side view which shows the example of an inductive coupling antenna. It is a perspective view which shows a sputter processing part and its periphery. It is a longitudinal cross-sectional view which shows an example of the laminated body obtained by the film-forming process. It is a figure which shows the reflectance spectrum of a laminated body at the time of forming into a transparent layer the silicon nitride film from which an optical constant is the same and from which film thickness differs. It is a figure which shows the flow of the whole process. A first laminate in which a titanium nitride film is formed as an opaque layer on a substrate, and a titanium nitride film is formed as an opaque layer on the substrate, and a silicon nitride film is formed thereon as a transparent layer. It is a figure which shows the reflectance spectrum about 2 laminated bodies.

  Hereinafter, embodiments of the present invention will be described with reference to the drawings. In the drawings, parts having similar configurations and functions are denoted by the same reference numerals, and redundant description is omitted. In addition, the following embodiment is an example which actualized this invention, and is not an example which limits the technical scope of this invention. In the drawings, the size and number of each part may be exaggerated or simplified for easy understanding. Also, in the drawings, XYZ orthogonal coordinate axes may be given to describe directions. The + Z direction on the coordinate axis is a vertically upward direction, and the XY plane is a horizontal plane.

<1 embodiment>
<1.1 Configuration of Sputtering Apparatus 1>
FIG. 1 is a schematic cross-sectional view schematically showing a schematic configuration of the sputtering apparatus 1. FIG. 2 is a schematic cross-sectional view showing the sputter processing unit 50 and its periphery. FIG. 3 is a side view showing an example of the inductively coupled antenna 151. FIG. 4 is a perspective view showing the sputter processing unit 50 and its periphery.

  The sputtering apparatus 1 is an apparatus that forms a film on the upper surface of a substrate 91 to be transported by sputtering. The base material 91 is composed of, for example, a SUS plate. Moreover, the laminated body obtained by performing the film-forming process with respect to the base material 91 is used, for example, as a decoration material in an interior or an exterior.

  The sputtering apparatus 1 includes a chamber 100 (processing chamber), a transport mechanism 30 that transports the base material 91, a sputtering processing unit 50 that performs film formation processing by sputtering on the upper surface of the transported base material 91, and the sputtering apparatus 1. And a control unit 190 that performs overall control of each unit. The chamber 100 is a hollow member having a rectangular parallelepiped shape. The chamber 100 is arranged such that its bottom plate and top plate are in a horizontal posture. Each of the X axis and the Y axis is an axis parallel to the side wall of the chamber 100.

  The sputtering apparatus 1 further includes a chimney 60 that is a cylindrical shielding member disposed so as to surround the periphery of the sputtering processing unit 50. The chimney 60 has a function as a shield that limits the range of plasma generated in the sputter processing unit 50 and the scattering range of sputtered particles sputtered from the target, and an atmosphere blocking function that blocks the atmosphere inside the chimney from the outside. Have. Hereinafter, among the internal spaces of the chamber 100, a space inside the chimney 60 where the sputtering process is performed is referred to as a processing space V.

  In the chamber 100, a horizontal transfer path surface L is defined below the chimney 60. The extending direction of the conveyance path surface L is the X-axis direction, and the base material 91 is conveyed along the X-axis direction.

  In addition, the sputtering apparatus 1 includes a plate-like heating unit 40 that heats the base material 91 that is transported in the chamber 100. The heating unit 40 is constituted by, for example, a sheath heater disposed on the lower side of the conveyance path surface L.

  A gate 160 for carrying the base material 91 into the chamber 100 is provided at the end of the transport path plane L on the −X side of the chamber 100. On the other hand, a gate 161 for carrying the base material 91 out of the chamber 100 is provided at the end of the transport path plane L on the + X side of the chamber 100. Moreover, the opening part of other chambers, such as a load lock chamber and an unload lock chamber, is connectable with the X direction both ends of the chamber 100 in the form which maintained airtight. Each of the gates 160 and 161 is configured to be openable and closable.

  The chamber 100 is connected to an exhaust unit 170 that exhausts the gas in the chamber 100. The exhaust unit 170 includes, for example, a vacuum pump (not shown), an exhaust pipe, and an exhaust valve. One end of the exhaust pipe is connected to the vacuum pump, and the other end is connected to the internal space of the chamber 100. Further, the exhaust valve is provided in the middle of the route of the exhaust pipe. Specifically, the exhaust valve is a valve that can automatically adjust the flow rate of the gas flowing through the exhaust pipe. In this configuration, when the exhaust valve is opened in a state where the vacuum pump is operated, the gas in the chamber 100 is exhausted and the chamber 100 is evacuated. The control unit 190 controls the exhaust by the exhaust unit 170, so that the pressure in the chamber 100 is adjusted to a specific value.

  The transport mechanism 30 includes a plurality of pairs of transport rollers 31 disposed opposite to each other across the transport path surface L in the Y direction inside the chamber 100, and a driving unit (not shown) that rotates and synchronizes these pairs. Consists of including. A plurality of pairs of the conveyance rollers 31 are provided along the X direction which is the extending direction of the conveyance path surface L. In FIG. 1, five rollers positioned on the near side (−Y side) of the five pairs of transport rollers 31 are illustrated.

  The carrier 90 is configured by a plate-like tray or the like, and the base material 91 is detachably held on the substantially horizontal upper surface of the carrier 90. Note that various modes such as a mode in which the base material 91 is held by the vacuum suction method and a mode in which the base material 91 is mechanically held by a chuck pin or the like can be adopted as the mode of holding the base material 91 in the carrier 90.

  When the carrier 90 on which the base material 91 is disposed is introduced into the chamber 100 through the gate 160, each transport roller 31 comes into contact with the vicinity of the edge (± Y side edge) of the carrier 90 from below. . Then, the carrier 90 and the base material 91 held by the carrier 90 are transported along the transport path surface L by synchronously rotating the transport rollers 31 by a drive unit (not shown). In the present embodiment, each conveyance roller 31 is rotatable in both clockwise and counterclockwise directions, and the carrier 90 and the substrate 91 held by the carrier 90 are conveyed in both directions (± X directions). explain. The transfer path surface L includes a deposition position P facing the sputtering processing unit 50 (film formation processing unit). For this reason, a film forming process is performed on a portion of the upper surface of the base material 91 that is transported by the transport mechanism 30 that is disposed at the deposition target position P.

  The sputtering apparatus 1 includes a sputtering gas supply unit 510 that supplies a sputtering gas such as argon gas that is an inert gas to the processing space V, and a reactive gas supply unit 520 that supplies a reactive gas such as nitrogen gas to the processing space V. With. Therefore, when one of the sputtering gas supply unit 510 and the reactive gas supply unit 520 supplies gas, an atmosphere of one gas is formed in the processing space V, and when both supply gas, the processing space. A mixed atmosphere of a sputtering gas and a reactive gas is formed in V.

  Specifically, the sputter gas supply unit 510 includes, for example, a sputtering gas supply source 511 that is a supply source of a sputtering gas, and a pipe 512. One end of the pipe 512 is connected to the sputtering gas supply source 511 and the other end is connected to each nozzle 514 communicating with the processing space V. Further, a valve 513 is provided in the course of the pipe 512. The valve 513 adjusts the amount of sputtering gas supplied to the processing space V under the control of the control unit 190. The valve 513 is preferably a valve that can automatically adjust the flow rate of the gas flowing through the pipe, and specifically includes, for example, a mass flow controller.

  Each nozzle 514 is provided on the ± X side of a row of inductive coupling antennas 151 provided between the rotary cathodes 5 and 6, and opens downward through the top plate of the chamber 100. For this reason, the sputtering gas supplied from the sputtering gas supply source 511 is introduced into the processing space V from each nozzle 514.

  Specifically, the reactive gas supply unit 520 includes, for example, a reactive gas supply source 521 that is a reactive gas supply source, and a pipe 522. One end of the pipe 522 is connected to the reactive gas supply source 521, and the other end is branched into a plurality (six in the example of FIG. 4) and a plurality of nozzles 12 (example of FIG. 4) provided in the processing space V. Then, a total of six nozzles 12) are connected, three on the + X side and three on the −X side. A valve 523 is provided in the middle of the route of the pipe 522. The valve 523 adjusts the amount of reactive gas supplied to the processing space V under the control of the control unit 190.

  Each nozzle 12 is provided so as to extend in the Y direction in a lower region of the processing space V. Each other end of the pipe 522 is connected to each outer end face of the X direction end faces of each nozzle 12. Each nozzle 12 is formed with a flow path that opens to each end face and is connected to the other end of the pipe 522 and branches into a plurality of portions inside the nozzle. The tip of each flow path reaches and opens each inner end face of both end faces in the X direction of the nozzle 12, and a plurality of discharge ports 11 are formed on each end face.

  An optical fiber probe 13 is provided above each nozzle 12 on the + X side. A spectroscope 14 capable of measuring the spectral intensity of plasma emission incident on the probe 13 is also provided. The spectroscope 14 is electrically connected to the control unit 190, and the measurement value of the spectroscope 14 is supplied to the control unit 190. The control unit 190 controls the valve 523 by the plasma emission monitor (PEM) method based on the output of the spectroscope 14, thereby introducing the reactive gas introduced into the chamber 100 from the reactive gas supply unit 520. To control. The valve 523 is preferably a valve that can automatically adjust the flow rate of the gas flowing through the pipe. For example, the valve 523 preferably includes a mass flow controller.

  Each component included in the sputtering apparatus 1 is electrically connected to the control unit 190, and each component is controlled by the control unit 190. Specifically, the control unit 190 includes, for example, a CPU that performs various arithmetic processes, a ROM that stores programs, a RAM that serves as a work area for arithmetic processes, a hard disk that stores programs and various data files, a LAN, and the like. A data communication unit having a data communication function via a general FA computer is connected to each other by a bus line or the like. The control unit 190 is connected to an input unit 191 that includes a display that performs various displays, a keyboard, a mouse, and the like. The input unit 191 is used, for example, when the operator of the apparatus designates and inputs color information when viewing the stacked body from one side (the upper side in FIG. 5).

  The sputter processing unit 50 is housed in the two rotary cathodes 5 and 6, the two rotary cathodes 19 that rotate the two rotary cathodes 5 and 6 about their respective central axes, and the two rotary cathodes 5 and 6, respectively. And two sputtering units 163 and 22 for supplying sputtering power to the two rotating cathodes 5 and 6, respectively.

  The rotating cathodes 5 and 6 are arranged to face each other with a certain distance in the X direction in the processing space V, and are configured as a cathode pair. By arranging the rotary cathodes 5 and 6 side by side in this manner, radicals are more concentrated on the film formation location P on the base material 91, and the film quality of the film obtained by the sputtering process can be improved.

  The sputter processing unit 50 includes a row of inductive coupling antennas 151 provided between the rotating cathodes 5 and 6, a matching circuit 154, and a high frequency power source 153 that supplies high frequency power to each inductive coupling antenna 151 via the matching circuit 154. And further comprising.

  Here, one line of inductively coupled antennas 151 means five inductively coupled antennas 151 provided at intervals along the Y direction.

  Therefore, the high frequency power supply 153 supplies high frequency power (for example, power having a frequency of 13.56 MHz) to each inductive coupling antenna 151, so that each inductive coupling antenna 151 provided inside the chimney 60 is within the processing space V. Inductively coupled plasma is generated.

  Each inductive coupling antenna 151 is covered with a dielectric protective member 152 made of quartz glass or the like, and is provided so as to protrude through the top plate of the chamber 100 into the internal space of the chamber 100.

  For example, as shown in FIG. 3, each inductive coupling antenna 151 is formed by bending a metal pipe-like conductor into a U shape, and penetrates the top plate of the chamber 100 in a “U” shape. Projecting in the internal space of the chamber 100. The inductively coupled antenna 151 is appropriately cooled, for example, by circulating cooling water therein.

One end of each inductively coupled antenna 151 is electrically connected to a high frequency power source 153 via a matching circuit 154. The other end of each inductively coupled antenna 151 is grounded. In this configuration, when high frequency power is supplied from the high frequency power source 153 to the inductively coupled antenna 151, a high frequency induced magnetic field is generated around the inductively coupled antenna 151, and inductively coupled plasma (ICP) is generated in the internal space of the chamber 100. Will occur. This inductively coupled plasma is a high-density plasma having an electron spatial density of 3 × 10 ¹⁰ atoms / cm ³ or more.

  In addition, the U-shaped inductively coupled antenna 151 as in this embodiment corresponds to an inductively coupled antenna having less than one turn, and has a lower inductance than an inductively coupled antenna having more than one turn. For this reason, the high frequency voltage generated at both ends of the inductive coupling antenna 151 is reduced, and the high frequency fluctuation of the plasma potential accompanying the electrostatic coupling to the generated plasma is suppressed. For this reason, excessive electron loss accompanying the plasma potential fluctuation to the ground potential is reduced, and the plasma potential can be suppressed particularly low. Thereby, damage to the base material 91 can be reduced.

  The magnet unit 21 (22) forms a magnetic field (static magnetic field) in the vicinity of itself on the outer peripheral surface of the rotating cathode 5 (6). A row of inductively coupled antennas 151 provided between the rotating cathodes 5 and 6 generate inductively coupled plasma in a space including a portion of the processing space V where a magnetic field is formed by the magnet units 21 and 22.

  The rotating cathode 5 (6) includes a cylindrical base member 8 extending in the Y direction perpendicular to the transport direction in a horizontal plane, and a cylindrical target 16 (17) covering the outer periphery of the base member 8. Configured. The base member 8 is a conductor, and the target 16 is made of a material containing silicon (Si) for forming a silicon nitride film, and the target 17 is made of a material containing titanium (Ti) for forming a titanium film. It is done. The rotating cathode 5 (6) may be configured by the cylindrical target 16 (17) without including the base member 8. The target 16 (17) is formed by, for example, a technique of compressing and molding the target material powder into a cylindrical shape, and then inserting the base member 8 or the like.

  In the present specification, when the rotating cathodes 5 and 6 arranged side by side and the magnet units 21 and 22 arranged inside each are integrally expressed, they are referred to as a magnetron cathode pair.

  Both end portions in the direction of the central axis 2 (3) of each base member 8 are respectively closed by lid portions each having a circular opening at the center portion. The length of the rotating cathode 5 (6) in the direction of the central axis 2 (3) is set to 1,400 mm, for example, and the diameter is set to 150 mm, for example.

  The sputter processing unit 50 further includes two pairs of seal bearings 9 and 10 and two cylindrical support rods 7. Each pair of the seal bearings 9 and 10 is provided with the rotary cathode 5 (6) sandwiched in the longitudinal direction (Y direction) of the rotary cathode 5 (6). Each of the seal bearings 9 and 10 includes a pedestal that is erected from the lower surface of the top plate of the chamber 100 and a substantially cylindrical cylindrical portion that is provided at the lower part of the pedestal.

  One end of each support bar 7 is supported by the cylindrical portion of the seal bearing 9, and the other end is supported by the cylindrical portion of the seal bearing 10. Each support bar 7 is inserted into the rotary cathode 5 (6) from the opening of the lid at one end of the base member 8, and passes through the rotary cathode 5 (6) along the central axis 2 (3). 8 is out of the rotating cathode 5 (6) through the opening of the lid at the other end.

  The magnet unit 21 (22) includes a yoke 25 (support plate) formed of a magnetic material such as permeable steel, and a plurality of magnets (a central magnet 23a and a peripheral magnet 23b described later) provided on the yoke 25. It is prepared for.

  The yoke 25 is a flat member and extends in the longitudinal direction (Y direction) of the rotary cathode 5 so as to face the inner peripheral surface of the rotary cathode 5 (6). A central magnet 23 a extending in the longitudinal direction of the yoke 25 is disposed on a center line along the longitudinal direction of the yoke 25 on the surface of the yoke 25 facing the inner peripheral surfaces of the rotary cathodes 5 and 6. On the outer edge portion of the surface of the yoke 25, an annular (endless) peripheral magnet 23b surrounding the periphery of the central magnet 23a is further provided. The central magnet 23a and the peripheral magnet 23b are constituted by permanent magnets, for example.

  The polarities of the center magnet 23a and the peripheral magnet 23b on the target 16 (17) side are different from each other. The polarities of the two magnet units 21 and 22 are configured to be complementary. For example, in the magnet unit 21, the central magnet 23 a on the target 16 (17) side has a north pole and the peripheral magnet 23 b has a south pole, while in the magnet unit 22, the central magnet on the target 16 (17) side. The polarity of 23a is the S pole and the polarity of the peripheral magnet 23b is the N pole.

  One end of the fixing member 27 is joined to the back surface of the yoke 25. The other end of the fixing member 27 is joined to the support bar 7. Thereby, the magnet units 21 and 22 are connected to the support rod 7. In the present embodiment, the magnet units 21 and 22 constituting the magnetron cathode pair are fixed in a state of being rotated by a predetermined angle in the −Z direction approaching the film-forming location P from a position facing each other. For this reason, a relatively strong static magnetic field is formed between the magnet units 21 and 22 in the space between the rotary cathodes 5 and 6 and on the film formation location P side.

  The base part of each seal bearing 9 is provided with a rotating part 19 having a motor and gears (not shown) for transmitting the rotation of the motor. In addition, gears (not shown) that mesh with the gears of the respective rotary portions 19 are provided around the opening of the + Y side lid portion of the base member 8 of the rotary cathodes 5 and 6.

  Each rotating portion 19 rotates the rotating cathode 5 (6) about the central axis 2 (3) by the rotation of the motor. More specifically, the rotating unit 19 is arranged around the central axes 2 and 3 so that the portions of the outer peripheral surfaces of the rotating cathodes 5 and 6 facing each other move from the lower side toward the upper side. The rotating cathodes 5 and 6 are rotated in the reverse direction. The rotation speed is set to, for example, 10 to 20 rotations / minute, and the constant rotation is performed at the rotation speed and the rotation direction described above during the sputtering process. The rotary cathodes 5 and 6 are appropriately cooled by circulating cooling water through the seal bearing 10 and the support rod 7.

  The electric wire connected to the power supply 163 for the sputter is branched into two and led into the sealed bearings 10 of the rotary cathodes 5 and 6. At the tip of each electric wire, a brush that contacts the lid portion on the −Y side of the base member 8 of the rotary cathodes 5 and 6 is provided. The power source 163 for sputter supplies sputtering power to the base member 8 through this brush. In this embodiment, as will be described later, the sputtering power source 163 first supplies a negative potential DC power to the rotating cathode 6, and then the sputtering power source 163 supplies a negative potential DC power to the rotating cathode 5.

  When sputtering power is supplied to each base member 8 (and thus each target 16, 17), plasma of sputtering gas is generated on the surface of each target 16, 17 in the processing space V. This plasma is confined with high density in the space between the rotating cathodes 5 and 6 and on the film-forming location P side by the static magnetic field formed by the magnet units 21 and 22. In the present specification, the plasma densified by the magnetic field confinement effect is referred to as magnetron plasma. In the embodiment in which the magnetron cathode pair generates magnetron plasma as in the present embodiment, the plasma is densified compared to the case where one magnetron cathode generates magnetron plasma. For this reason, the aspect of this embodiment is desirable from the viewpoint of improving the film formation rate.

  As described above, one row of inductively coupled antennas 151 provided between the rotating cathodes 5 and 6 generates inductively coupled plasma in a space including a portion where a magnetic field is formed by the magnet units 21 and 22 in the processing space V. To do. As a result, the magnetron plasma generated by the magnetron cathode pair and the inductively coupled plasma generated by the inductively coupled antenna 151 overlap each other to form a mixed plasma. The high-density inductively coupled plasma generated by the inductively coupled antenna 151 also contributes to sputtering of the targets 16 and 17 together with the magnetron plasma generated by the magnetic units 21 and 22 in the vicinity of the outer peripheral surfaces of the rotating cathodes 5 and 6. .

  When the inductively coupled plasma contributes to sputtering in this way, the sputtering voltage can be lowered even when the sputter power supplied to the rotating cathodes 5 and 6 is the same as compared with the case where no inductively coupled plasma contributes ( Impedance can be reduced). Thereby, the film forming process is executed at a high film forming rate while the damage given to the film forming surface of the base material 91 by recoil argon or negative ions flying from the targets 16 and 17 is reduced.

  In the sputtering process, a sputtering gas and a reactive gas are introduced into the processing space V of the chamber 100 to sputter the targets 16 and 17 covering the outer periphery of the rotating cathodes 5 and 6 in the mixed plasma atmosphere. , 17, a titanium film and a silicon nitride film are formed on the substrate 91 facing each other.

<1.2 Relationship Between Film Thickness of Transparent Layer 201 and Color of Laminate 200>
FIG. 5 is a longitudinal sectional view showing an example of a laminated body 200 obtained by a film forming process. As shown in FIG. 5, in this embodiment, the sputtering apparatus 1 forms two layers of films on one side of the upper surface of the base material 91, so that the transparent layer 201 is sequentially viewed from one side (the upper side in the figure). And a laminated body 200 having a metal opaque layer 202 is obtained.

  Below, the technique which adjusts the color of the laminated body 200 when performing the film-forming process to the base material 91 and obtaining the laminated body 200 is demonstrated. In the present specification, the “color of the laminated body 200” means a color when the laminated body 200 is viewed from the one side.

  Hereinafter, a correspondence relationship in which each optical constant of each layer constituting the stacked body 200, the film thickness of the transparent layer 201, and the color information of the stacked body 200 are associated will be described with reference to the mathematical formulas 1 to 18. . In each formula, the subscript “0” means air, the subscript “1” means the film to be deposited, and the subscript “2” means the substrate 91. . The subscript “p” means p-polarized light, and the subscript “s” means s-polarized light.

  When the complex refractive index is N, the following formula 1 is established using the optical constant (refractive index n and extinction coefficient k) and imaginary number i.

  Further, when the incident angle to each layer is θ, the following formula 2 is established according to Snell's law.

  At this time, if the phase change is β, the following equation 3 holds.

  When the amplitude reflection coefficient is r, the amplitude transmission coefficient is t, the reflectance is R, and the film thickness of the transparent layer 201 is d, the following equations 4 to 9 are established from the Fresnel equation.

  FIG. 6 is a diagram showing the reflectance spectrum of the stacked body 200 when silicon nitride films having the same optical constant and different film thicknesses are formed as the transparent layer 201. In FIG. 6, the horizontal axis indicates the wavelength, and the vertical axis indicates the reflectance.

  When the reflectance distribution is S (λ) and the color matching functions in the XYZ color system are x (λ), y (λ), and z (λ), the following equations 10 to 13 are established.

Here, when color conversion is performed from the XYZ color system to the L ^* a ^* b ^* color system, the following equations 14 to 18 are established.

  As described above, a correspondence relationship in which the optical constants of the respective layers constituting the stacked body 200, the film thickness of the transparent layer 201, and the color information are associated in a one-to-one manner is obtained by theoretical calculation.

  As shown in FIG. 6, in the stacked body 200, the reflectance in the visible region (wavelength region of about 380 nm to 780 nm) is increased as the thickness of the opaque layer 202 made of a silicon nitride film increases from 60 nm to 90 nm. It can be seen that the maximum peak of is shifted to the long wavelength side. That is, when the film thickness of the transparent layer 201 is 60 nm, the color of the laminated body 200 becomes a bluish blue, and when the film thickness of the transparent layer 201 is 90 nm, the color of the laminated body 200 is more red. It turns out that it becomes blue with a taste.

  As described above, even when the sputtering process is performed under the same conditions such as the gas supply amount, the sputtering voltage value, the high-frequency power value, and the pressure value in the chamber, the laminated body 200 having a constant optical constant is obtained. As long as the film thickness of the transparent layer 201 is adjusted according to the processing time, the color of the laminate 200 can be adjusted.

  In addition, when the sputtering process is performed with various conditions such as the gas supply amount, the sputtering voltage value, the high-frequency power value, the pressure value in the chamber, etc., and the optical constant is adjusted to obtain the laminated body 200, it is transparent depending on the processing time. By adjusting the film thickness of the layer 201, the color of the stacked body 200 can be adjusted in a wider range.

  The reason why the color of the laminate 200 changes depending on the film thickness of the transparent layer 201 is considered as follows. When irradiation light is applied to the multilayer body 200 from the one side, the irradiation light is reflected by the surface of the one side of the multilayer body 200 (that is, the surface of the transparent layer 201) to obtain first reflected light. Further, when irradiation light is applied to the laminate 200 from the one side, it passes through the transparent layer 201 of the laminate 200 and is reflected at the interface between the transparent layer 201 and the metal opaque layer 202 (reflective layer). Second reflected light is obtained. It is considered that the color adjustment of the laminate 200 is realized by the action of the first reflected light and the second reflected light interfering with each other. Then, since the interference action changes according to the film thickness of the transparent layer 201, it is considered that the color of the laminate 200 can be adjusted by adjusting the film thickness of the transparent layer 201.

<1.3 Processing example>
<1.3.1 Process Flow>
FIG. 7 is a diagram showing the overall flow of processing in the present embodiment.

  Hereinafter, a case will be described in which the sputtering process is performed under the same conditions as the sputtering process performed in the past, and the stacked body 200 having the same optical constant as that of the stacked body 200 obtained in the past process is described. As described above, also in this case, the color of the stacked body 200 can be adjusted by adjusting the film thickness of the opaque layer 202 according to the processing time.

Prior to the sputtering process, the color information (for example, one color in the L ^* a ^* b ^* color system) is associated with the film forming conditions for obtaining the laminate 200 that has the color when viewed from the one side. Data is stored in the storage unit of the control unit 190 (step ST1). Specifically, in this embodiment, the operator actually measured each optical constant (refractive index and extinction coefficient) for each layer of the laminate 200 using a measuring device such as ellipsometry during the past processing. Each optical constant and the corresponding relationship are stored in advance in the storage unit of the control unit 190.

After the correspondence data is stored in the control unit 190, the operator of the apparatus can specify the color of the stacked body 200 from the input unit 191 in the sputtering process. Specifically, the operator inputs color information (for example, each value of L ^* a ^* b ^* ) of a color desired as the obtained stacked body 200 to the input unit 191 (step ST2).

  The control unit 190 determines whether the color information input from the input unit is included in the compatible range of the corresponding data (step ST3). Here, when the color information is included in the compatible range of the corresponding data, the case where there is a film forming condition capable of forming a color film that completely matches the color information input in the corresponding data corresponds to This includes both the case where there is a film forming condition in which a film having a color whose deviation from the color information input in the data is within an allowable range exists.

  If the input color information is included in the compatible range of the corresponding data, the process branches to Yes in step ST3, and the control unit 190 refers to the corresponding data based on the color information input from the input unit 191. Then, the film forming conditions for obtaining the laminate 200 of that color are determined by the sputtering apparatus 1 (step ST4). Thereafter, a sputtering process to be described later is executed (step ST5).

  On the other hand, if the input color information is not included in the compatible range of the corresponding data, the process branches to No in step ST3, and the control unit 190 informs the operator of the fact through a display on the display or a warning sound. (Step ST6).

  Thus, in addition to the function of controlling each part of the apparatus, the control unit 190 has a function as a determination unit that determines whether an input color can be formed, a function as a determination unit that determines film formation conditions, And a function as a notification unit for notifying the operator when the input color cannot be formed.

  In the present embodiment, the film formation conditions are determined with reference to correspondence data in which color information and film formation conditions are associated with each other. For this reason, in the aspect of the present embodiment, it is possible to obtain a laminate 200 of a desired color with high accuracy and stability, compared to other aspects in which colors and film forming conditions are associated with each other based on operator intuition and empirical rules. .

  In the present embodiment, when the input color information is not included in the compatible range of the corresponding data, the operator is notified immediately. For this reason, it is desirable that the time and labor required for the operator to perform trial and error for colors that cannot be formed by the current correspondence data are omitted.

  Further, in this case, the operator of the apparatus can use other elements other than the film thickness as elements for color adjustment in the film forming conditions (for example, gas supply amount, sputtering voltage value, high-frequency power value, pressure value in the chamber, etc.) Corresponding data may be created while changing the optical constant while changing. As a result, the correspondence data is updated and the number of data increases, so that it is possible to form a color that cannot be formed with the correspondence data at the previous time point with the updated correspondence data.

<1.3.2 Sputter treatment>
The flow of the sputtering process in step ST5 will be described.

  First, an atmosphere of argon gas is formed in the processing space V by the sputtering gas supply unit 510. High frequency power is supplied to each inductive coupling antenna 151 disposed between the rotary cathodes 5 and 6 by a high frequency power source 153. Thereby, inductively coupled plasma is generated in the processing space V. In addition, when inductively coupled plasma is generated in the processing space V, the exhaust unit 170 exhausts the gas in the chamber 100 until a process pressure suitable for performing plasma processing in the chamber 100 is reached. When the pressure in the chamber 100 reaches the process pressure, sputtering power is supplied to the rotating cathode 6 by the sputtering power source 163. Thereby, a magnetron plasma is generated at the center position in the Y direction of the processing space V. As a result, the mixed plasma of the magnetron plasma and the inductively coupled plasma is generated at the center position in the Y direction of the processing space V (specifically, between the rotary cathodes 5 and 6 and in the space on the deposition site P side). It is formed.

  In this state, the transport mechanism 30 loads the base material 91 from the gate 160 and transports the base material 91 along the transport path surface L. More specifically, the transport mechanism 30 moves the base material 91 in the ± X direction along the transport path surface L so that the base material 91 passes through the film formation location P a plurality of times. Moreover, the base material 91 by which the heating part 40 is conveyed is heated. As a result, titanium particles sputtered from the target 17 of the rotating cathode 6 are crystallized and deposited on the upper surface of the substrate 91 to be transported to form a titanium film. As a result, an opaque layer 202 containing titanium as a main component is formed on the upper surface of the substrate 91.

  Thereafter, supply of the reactive gas into the processing space V by the reactive gas supply unit 520 is started, and a mixed atmosphere of nitrogen gas and argon gas is formed in the processing space V. Further, the control unit 190 controls the sputtering power source 163 to switch from the state in which the sputtering power is supplied to the rotating cathode 6 to the state in which the sputtering power is supplied to the rotating cathode 5. Further, after this switching, the high frequency power is continuously supplied to each inductive coupling antenna 151 by the high frequency power supply 153.

  In this state, the transport mechanism 30 moves the base material 91 in the ± X direction along the transport path surface L so that the base material 91 passes through the deposition position P a plurality of times. Moreover, the base material 91 by which the heating part 40 is conveyed is heated. As a result, silicon nitride particles sputtered from the target 16 of the rotary cathode 5 are crystallized on the upper surface of the substrate 91 to be conveyed (more specifically, the upper surface of the opaque layer 202 formed on the substrate 91). Then, a silicon nitride film is formed. Thereby, the transparent layer 201 mainly composed of silicon nitride is formed on the upper surface of the base material 91.

  When the predetermined processing time elapses and the film thickness of the transparent layer 201 reaches the film thickness input from the input unit 191, the sputtering process ends. Specifically, the application of the sputtering voltage to the rotating cathode 5 by the sputtering power source 163 is stopped. The supply of the sputtering gas by the sputtering gas supply source 511 is stopped. Further, the supply of the reactive gas by the reactive gas supply source 521 is stopped. Further, the supply of the high frequency power to each inductive coupling antenna 151 by the high frequency power supply 153 is stopped. Then, the transport mechanism 30 unloads the substrate 91 after film formation from the gate 161 to the outside of the sputtering apparatus 1.

  The laminate 200 obtained in the present embodiment includes, in order from the one side, a transparent layer 201 containing silicon nitride as a main component and an opaque layer 202 containing titanium as a main component. And the color at the time of seeing the laminated body 200 from the said one side has dependence with respect to the film thickness of the transparent layer 201 (FIG. 6).

  Since the film thickness of the transparent layer 201 can be easily adjusted by the processing time of the sputtering process, the color of the laminate 200 can be easily adjusted, which is desirable.

  In general, alloy targets are more expensive than single metal targets. For this reason, compared to other embodiments in which an alloy target is sputtered to obtain a laminate of a desired color, a single metal target is sputtered while adjusting the processing time to obtain a laminate 200 of the desired color. In the embodiment, the laminate 200 can be generated at a low cost.

  Further, when the transparent layer 201 is a functional film, the transparent layer 201 is provided on the most surface side of the stacked body 200, and thus the function of the transparent layer 201 is imparted to the stacked body 200, which is desirable. For example, a silicon nitride film is excellent in chemical function (solvent resistance, acid resistance, base resistance) and mechanical function.

  Further, the opaque layer 202 containing titanium as a main component has a function as an adhesion layer that improves the adhesion of the transparent layer 201 to the base material 91. For this reason, compared with the other aspect which forms the transparent layer 201 directly on the base material 91, and obtains a laminated body, the transparent layer 201 and the base material 91 are closely_contact | adhered through the opaque layer 202 of this embodiment. In the aspect, the transparent layer 201 is hardly peeled off from the laminate 200. As described above, the laminated body 200 is used as a decorative material for interior or exterior of a building, and the laminated body 200 is subjected to processing such as cutting and bending as necessary. In view of the technical field of processing in this way, it is particularly effective that the laminate 200 has the opaque layer 202 as an adhesion layer.

<2 Modification>
While the embodiments of the present invention have been described above, the present invention can be modified in various ways other than those described above without departing from the spirit of the present invention.

  FIG. 8 shows a first laminate in which a titanium nitride film is formed as an opaque layer 202 on a base material 91, and a titanium nitride film is formed as an opaque layer 202 on the base material 91, and further a transparent layer 201 is formed thereon. FIG. 6 is a diagram showing a reflectance spectrum of a second stacked body in which a silicon nitride film is formed as a film. In FIG. 8, the horizontal axis indicates the wavelength, and the vertical axis indicates the reflectance.

  The second laminate has a transparent layer (silicon nitride film) and a metal opaque layer (titanium nitride film) in this order as viewed from the one side, and the color of the laminate is relative to the film thickness of the transparent layer. Has dependency. Therefore, the 2nd laminated body in this modification is also contained in the scope of the present invention. As shown in FIG. 8, the reflectance spectrum of the second stacked body is substantially 0 in the visible region. Thus, the color of the laminate can be made closer to black by adjusting the film thickness of the transparent layer.

  Moreover, although the said embodiment demonstrated the aspect whose transparent layer 201 is a silicon nitride layer, it is not restricted to this. For example, the transparent layer 201 may be a titanium oxide layer. In this case, the antifouling property of the laminate 200 is particularly enhanced by the catalytic effect of titanium oxide. The transparent layer 201 may be an aluminum oxide layer. In this case, since the hardness of aluminum oxide is high, the wear resistance of the laminate 200 is particularly enhanced. The transparent layer 201 may be a titanium nitride layer. In this case, since titanium nitride is chemically stable, the corrosion resistance of the laminate 200 is particularly enhanced.

  Moreover, although the said embodiment demonstrated the aspect which forms the film | membrane of two layers on the base material 91 and obtains the laminated body 200, it is not restricted to this. A laminated body may be obtained by forming a single film on the substrate 91. In this case, the present invention can be applied by the base material 91 functioning as a metal opaque layer and the single layer film functioning as a transparent layer. Alternatively, a laminate may be obtained by forming three or more layers on the substrate 91. Even in this case, the present invention can be applied because the laminate includes a metal opaque layer and a transparent layer.

  Moreover, although the said embodiment demonstrated the aspect in which the base material 91 was comprised with a SUS board, as the base material 91, resin, wood, glass, etc. may be used.

  Moreover, although the said embodiment demonstrated the aspect which uses the sputtering apparatus 1 as a film-forming apparatus, it is not restricted to this. The present invention can also be applied to other film forming apparatuses (for example, a vapor deposition apparatus).

Moreover, although the said embodiment demonstrated the case where the color information input into the input part 191 is color information in a L ^* a ^* b ^* color system, it is not restricted to this. The color information input to the input unit 191 may be color information in a color system other than the L ^* a ^* b ^* color system such as the XYZ color system.

  Moreover, although the said embodiment demonstrated the aspect in which the conveyance mechanism 30 which conveys holding the base material 91 as a base material holding part was demonstrated, the base material holding part which hold | maintains the base material 91 in a stationary state is used. It doesn't matter. Further, the direction in which the transport mechanism 30 transports the base material 91 may be, for example, the vertical direction in addition to the horizontal direction as in the above embodiment.

  Moreover, although the said embodiment demonstrated each aspect which provided each inductive coupling antenna 151 by protruding through the top plate of the chamber 100 and protruding in the internal space of the chamber 100, it is not restricted to this. Each inductive coupling antenna 151 may be provided so as to penetrate the side wall or bottom plate of the chamber 100 and protrude into the internal space of the chamber 100. Further, each inductively coupled antenna 151 may be provided in such a manner that it is embedded in the inner wall (top plate, side wall, or bottom plate) of the chamber 100 and does not protrude into the internal space of the chamber 100.

  Moreover, although the case where the two rotating cathodes 5 and 6 were arranged in parallel was demonstrated in the said embodiment, one rotating cathode may be sufficient. Further, instead of using a rotating cathode, a flat cathode may be used.

  Moreover, although the said embodiment demonstrated the case where the number of the inductive coupling antennas 151 which comprise 1 row was five, this number should just change suitably according to the length of the rotating cathode 5 (6). . A plurality of rows of inductively coupled antennas 151 may be provided. In addition, design items such as the position, number, and length of each part can be changed as appropriate.

  Moreover, although the said embodiment demonstrated the aspect in which the film-forming process was performed on the upper surface among the surfaces of the base material 91 conveyed, it is not restricted to this. For example, a film forming process may be performed on the other surface (side surface, lower surface, or the like) of the surface of the substrate 91 to be conveyed, or a plurality of surfaces (for example, the surface of the substrate 91 to be conveyed (for example, , The upper surface and the lower surface) may be simultaneously formed.

  As described above, the film forming apparatus and the laminate according to the embodiment and the modifications thereof have been described. However, these are examples of the preferred embodiment of the present invention, and do not limit the scope of the present invention. Within the scope of the invention, the present invention can be freely combined with each embodiment, modified with any component in each embodiment, or increased or decreased with any component in each embodiment.

DESCRIPTION OF SYMBOLS 1 Sputtering device 5,6 Rotating cathode 7 Support rod 8 Base member 16,17 Target 19 Rotating part 21,22 Magnet unit 30 Conveying mechanism 31 Conveying roller 50 Sputter processing part 100 Chamber 151 Inductive coupling antenna 153 High frequency power supply 163 Power supply for sputter 190 Control unit 191 Input unit 60 Chimney 90 Carrier 91 Base material 200 Laminate 201 Transparent layer 202 Opaque layer 510 Sputter gas supply unit 520 Reactive gas supply unit V Processing space

Claims (16)

A film forming apparatus for obtaining a laminate by forming at least one film on one side of a surface of a substrate,
A processing chamber having a processing space therein;
A substrate holding part for holding the substrate in the processing chamber;
A gas supply unit for supplying gas to the processing space;
An exhaust section for discharging the gas in the processing chamber;
A film formation processing unit that performs a film formation process on the surface of the base material held by the base material holding unit;
An input unit for inputting color information when the laminate is viewed from the one side;
For a plurality of colors, a storage unit storing correspondence data in which color information is associated with film forming conditions for obtaining the laminate that is the color when viewed from the one side;
A determination unit that determines the film formation condition with reference to the corresponding data based on the color information input from the input unit;
With
The laminate has a transparent layer and a metal opaque layer in order as viewed from the one side,
The film forming condition is characterized in that at least the film thickness of the transparent layer is included as an element of color adjustment. The film forming apparatus according to claim 1,
The first reflected light obtained by reflecting the irradiation light on the surface of the one side of the laminate when the irradiation light is applied to the laminate from the one side, and the irradiation light to the laminate from the one side The color adjustment is performed by the action of interference between the second reflected light obtained by passing through the transparent layer of the laminate and reflecting at the interface between the transparent layer and the metal opaque layer. Realized,
The film forming apparatus characterized in that the interference action changes according to the film thickness of the transparent layer. The film forming apparatus according to claim 1 or 2,
A determination unit that determines whether or not the color information input from the input unit is included in a compatible range of the corresponding data;
When the color information is not included in the available range, a notification unit that notifies the operator of the fact,
The film forming apparatus further comprising: A film forming apparatus according to any one of claims 1 to 3,
The correspondence data is data in which each optical constant of each layer constituting the laminate and the film thickness of the transparent layer are associated with color information of the laminate viewed from the one side by theoretical calculation. A film forming apparatus characterized in that: A film forming apparatus according to any one of claims 1 to 4,
The film forming apparatus, wherein the laminate is used as a decorative material for an interior or exterior of a building. A film forming apparatus according to any one of claims 1 to 5,
The film forming apparatus, wherein the transparent layer is a silicon nitride layer. A film forming apparatus according to any one of claims 1 to 5,
The film forming apparatus, wherein the transparent layer is a titanium oxide layer. A film forming apparatus according to any one of claims 1 to 5,
The film forming apparatus, wherein the transparent layer is an aluminum oxide layer. A film forming apparatus according to any one of claims 1 to 5,
The film forming apparatus, wherein the transparent layer is a titanium nitride layer. A laminate obtained by forming a film of at least one layer on one side of the surface of the substrate,
In order from the one side,
A transparent layer,
A metal opaque layer,
Have
The laminated body, wherein the color when the laminated body is viewed from the one side has a dependency on the film thickness of the transparent layer. The laminate according to claim 10, wherein
The dependency is obtained by reflecting the irradiation light on the surface of the one side of the laminate when the irradiation light is applied to the laminate from the one side, and the first reflection light obtained from the one side. When the irradiation light is applied to the laminate, the second reflected light obtained by passing through the transparent layer of the laminate and reflecting at the interface between the transparent layer and the metal opaque layer interferes. Is due to
A laminate in which this interference action changes according to the film thickness of the transparent layer. It is a laminated body of Claim 10 or Claim 11,
A laminate characterized by being used as a decorative material for the interior or exterior of a building. A laminate according to any one of claims 10 to 12,
The laminated body, wherein the transparent layer is a silicon nitride layer. A laminate according to any one of claims 10 to 12,
The laminated body, wherein the transparent layer is a titanium oxide layer. A laminate according to any one of claims 10 to 12,
The laminated body, wherein the transparent layer is an aluminum oxide layer. A laminate according to any one of claims 10 to 12,
The laminated body, wherein the transparent layer is a titanium nitride layer.

Images