Decorative film formation device, decorative film formation method, and decorative base material

Abstract

The present invention provides a technology with which it is possible to easily perform decoration for causing a base material to develop a color. This decorative film formation device comprises: a chamber; a titanium particle discharge unit which includes a titanium target disposed in the chamber and applies energy to the titanium target so as to discharge titanium particles; a gas supply unit which is connected to the chamber and supplies a reactive gas; and a control unit which controls the gas supply unit. The gas supply unit has: a carbon-containing gas supply unit for supplying a carbon-containing gas that contains carbon atoms into the chamber; a nitrogen-containing gas supply unit for supplying a nitrogen-containing gas that contains nitrogen atoms into the chamber; and a flow rate adjustment unit which is capable of adjusting the flow rate of the carbon-containing gas with respect to the flow rate of the nitrogen-containing gas. The control unit adjusts the visible light reflectance of a film that is formed on a film formation object by adjusting the flow rate of the carbon-containing gas using the flow rate adjustment unit.

Description

Decorative film formation apparatus, decorative film formation method, and decorative substrate

[0001] The subject matter disclosed herein relates to a decorative film deposition apparatus, a decorative film deposition method, and a decorative substrate.

[0002] Titanium nitride (TiN) is widely used for decorating ornaments and building materials because it can produce gold to bronze colors. Similarly, titanium aluminum nitride (TiAlN) is used for similar applications because it can produce blue and black colors. Unlike the interference colors seen in transparent thin films, these coatings are opaque films that absorb light, resulting in a complex coloration due to both interference colors and the coloration of the film itself. Because TiN and TiAlN have inherent color, their color is less likely to change with changes in film thickness due to friction, etc., and because the films are very hard, they are resistant to deterioration such as wear.

[0003] TiN and TiAlN can be deposited using methods such as vacuum deposition, arc ion plating, and sputtering, but sputtering is generally used due to its high production efficiency. For TiN sputtering, reactive sputtering using a Ti target and argon (Ar) / nitrogen (N2) gas is employed to coat / deposit the material to be decorated. Similarly, for TiAlN sputtering, a titanium aluminum (TiAl) alloy target is generally used. In actual film deposition examples, titanium (Ti) or titanium aluminum (TiAl) is deposited on the substrate as an adhesion layer by sputtering, and then TiN or TiAlN is deposited on top of that as a decorative layer to perform the decoration.

[0004] Furthermore, Patent Document 1 describes how to obtain a desired decorated resin molded product by directly forming a titanium nitride thin film on the decorative surface of a resin molded product using physical vapor deposition or chemical vapor deposition.

[0005] Japanese Patent Publication No. 2018-024202

[0006] However, with the conventional sputtering decoration method described above, applying a gold or other colored coating with a titanium target, followed by a blue or black coating, required returning the vacuum in the sputtering apparatus to atmospheric pressure, opening the sputtering chamber, and replacing the titanium target with a titanium-aluminum target. Similarly, if a gold or other colored coating, which can only be achieved with a titanium target, was required, the sputtering chamber had to be opened to the atmosphere and the titanium-aluminum target replaced with a titanium target. Furthermore, after target replacement, a waiting time occurred for the vacuum to be evacuated and for moisture adsorbed on the chamber walls during the target replacement to be released, resulting in reduced production efficiency. In addition, opening to the atmosphere altered the environment inside the chamber, reducing the reproducibility of color development and frequently requiring color adjustments.

[0007] Furthermore, the technology described in Patent Document 1 offers excellent productivity because it can produce blue color using only TiN. However, the substrate is limited to resin molded products with an L* value of 72.75 or less in the L*a*b* color system, resulting in extremely low versatility, and in some cases, it was difficult to decorate the substrate to produce the desired color.

[0008] The object of the present invention is to provide a technology that can easily perform decoration to color a substrate.

[0009] To solve the above problems, the first embodiment is a decorative film deposition apparatus for performing a film deposition process on a substrate, comprising: a chamber; a titanium particle emission unit including a titanium target disposed in the chamber and which imparts energy to the titanium target to release titanium particles; a gas supply unit connected to the chamber and which supplies a reactive gas; and a control unit that controls the gas supply unit, wherein the gas supply unit comprises a carbon-containing gas supply unit that supplies a carbon-containing gas containing carbon atoms into the chamber; a nitrogen-containing gas supply unit that supplies a nitrogen-containing gas containing nitrogen atoms into the chamber; and a flow rate adjustment unit that can adjust the flow rate of the carbon-containing gas with respect to the flow rate of the nitrogen-containing gas, and the control unit adjusts the flow rate of the carbon-containing gas by the flow rate adjustment unit to adjust the visible light reflectance of the film formed on the object to be deposited.

[0010] The second embodiment is a decorative film deposition apparatus according to the first embodiment, wherein the titanium particle emission unit comprises a cathode containing the titanium target and a voltage application unit for applying a voltage to the cathode, and the gas supply unit further comprises a sputter gas supply unit for supplying sputter gas for sputtering the titanium target into the chamber.

[0011] A third embodiment further comprises a conveying unit that transports a substrate relative to the titanium target so as to pass around the titanium target within the chamber, in the decorative film deposition apparatus of the second embodiment.

[0012] A fourth aspect is a decorative film formation method for forming a film on a substrate, comprising the steps of: placing the substrate in a chamber; applying energy to a titanium target placed in the chamber to release titanium particles; supplying gas into the chamber; and controlling the flow rate of the gas supplied into the chamber by the gas supply step, wherein the gas supply step involves supplying a carbon-containing gas containing carbon atoms and a nitrogen-containing gas containing nitrogen atoms into the chamber; and the control step involves adjusting the flow rate of the carbon-containing gas to adjust the visible light reflectance of the film formed on the object to be film-formed.

[0013] A fifth embodiment is a decorative substrate comprising a substrate and a titanium carbonitride film formed on the substrate, wherein the average reflectance of the titanium carbonitride film in the wavelength range of 600 nm to 800 nm is smaller than the average reflectance in the wavelength range of 400 nm to 500 nm.

[0014] The sixth embodiment is a decorative substrate according to the fifth embodiment, wherein the average reflectance of the titanium carbonitride film in the wavelength range of 600 nm to 800 nm is 20% or less.

[0015] According to the first to fourth embodiments, films with different visible light reflectances can be easily formed by adjusting the addition rate of carbon-containing gas. Therefore, decorations that produce the target color can be applied to the substrate efficiently and stably.

[0016] According to the decorative film deposition apparatus of the second embodiment, film deposition can be performed by sputtering.

[0017] According to the third embodiment of the decorative film deposition apparatus, the film deposition process can be performed continuously on the substrate.

[0018] According to the decorative substrates of the fifth to sixth embodiments, the substrate can be colored blue by the titanium carbonitride film.

[0019] This figure shows the configuration of a sputtering apparatus according to an embodiment. This figure schematically shows an example of the plasma processing unit and its surroundings. This is a flowchart showing a decorative film deposition method using the sputtering apparatus shown in Figure 1. This is a graph showing the refractive index for each of the five types of thin films. This is a graph showing the extinction coefficient for each of the five types of thin films. This figure shows the reflection spectra for each of the five types of thin films. This figure shows the Lab* color system for each of the five types of thin films calculated from the reflection spectra.

[0020] The embodiments will be described below with reference to the drawings. In the drawings, parts having the same or similar configuration and function will be denoted by the same reference numeral, and redundant explanations may be omitted. In the drawings, the dimensions and number of parts may be exaggerated or simplified in order to facilitate understanding. Also, each drawing may include XYZ Cartesian coordinate axes as appropriate to explain direction. In the coordinate axes, the Z direction indicates the vertical direction, and the XY plane indicates the horizontal plane. Hereafter, one side of the X direction may be referred to as the +X side, and the opposite side as the -X side. The same applies to the Y axis and Z axis. The +Z side indicates the vertically upward side.

[0021] <1. Embodiment> Figure 1 is a diagram showing the configuration of a sputtering apparatus 1 according to an embodiment. The sputtering apparatus 1 is a decorative film-forming apparatus that produces a decorated substrate 91 by forming a thin film on the film-forming target surface of the substrate 91 by continuous sputtering. The substrate 91 is, for example, a glass substrate. The sputtering apparatus 1 performs, for example, reactive sputtering. The thin film formed by the sputtering apparatus 1 is specifically titanium carbonitride (TiCN). Here, the case of forming a single thin film will be described, but a multilayer film may be formed by laminating thin films. As shown in FIG. 1, the sputtering apparatus 1 includes a chamber 100, a transport unit 10, a plasma processing unit 20, a gas supply unit 500, and a control unit 200.

[0022] The chamber 100 is, for example, a vacuum chamber and is a hollow member having a rectangular parallelepiped shape. The chamber 100 is arranged such that the upper surface of its bottom plate is in a horizontal posture. Each of the X-axis and the Y-axis is parallel to the side wall of the chamber 100.

[0023] The transport unit 10 is provided in the chamber 100, holds the substrate �1, and transports the substrate 91 along the transport path L. The transport path L extends in the X direction, which is the horizontal direction.

[0024] The gas supply unit 500 supplies a sputter gas and a reactive gas into the processing space V described later. As the sputter gas, for example, an inert gas such as argon gas or xenon gas can be used. The reactive gas is a carbon-containing gas and a nitrogen-containing gas. The carbon-containing gas is a gas containing carbon atoms, specifically methane (CH ４ ), propane (C ３ H ８ ), butane (C ４ H １０ ), acetylene (C ２ H ２ ), or toluene (C ７ H ８ ). The nitrogen-containing gas is a gas containing nitrogen atoms, specifically nitrogen (N ２ ), ammonia (NH ３ ), or hydrazine (N２ H ４ ) and so on.

[0025] The plasma processing unit 20 is located within the processing space V, opposite the transport path L. In the example shown in Figure 1, the plasma processing unit 20 is located away from the transport path L on the -Z side.

[0026] Figure 2 is a schematic diagram showing an example of a plasma processing unit 20 and its surroundings. As shown in Figure 2, the plasma processing unit 20 includes a titanium target 32. The plasma processing unit 20 generates plasma and performs sputtering on the titanium target 32. Titanium particles ejected from the titanium target 32 ​​by sputtering react with carbon and nitrogen contained in the reactive gas and are deposited on the film deposition target surface of the substrate 91, forming a thin film (film deposition process).

[0027] As the transport unit 10 transports the substrate 91 along the transport path L from the -X side to the +X side, the substrate 91 passes over the plasma processing unit 20 in a plan view. As the substrate 91 passes over the plasma processing unit 20, it undergoes a substantial film deposition process from the plasma processing unit 20. In other words, as the substrate 91 passes over the plasma processing unit 20, a thin film is formed on the film deposition target surface of the substrate 91.

[0028] As shown in Figure 1, the sputtering apparatus 1 further includes a temperature control unit 120. The temperature control unit 120 is located, for example, on the opposite side of the transport path L from the plasma processing unit 20 (the +Z side in Figure 1). The temperature control unit 120 heats or cools the substrate 91 being transported within the chamber 100. Note that the temperature control unit 120 is optional.

[0029] As shown in Figure 1, the sputtering apparatus 1 further comprises a chimney 130. The chimney 130 is a partition member, positioned within the chamber 100 to surround the plasma processing unit 20, and has an opening on the transport path L side (the +Z side in the figure). This opening faces a part of the transport path L in the Z direction. Hereinafter, the internal space of the chimney 130 and the space between the opening of the chimney 130 and the transport path L will be defined as the processing space V.

[0030] As shown in Figure 1, a gate 160 for loading the substrate 91 into the chamber 100 is located at the -X end of the transport path L in the chamber 100. A gate 161 for unloading the substrate 91 from the chamber 100 is located at the +X end of the transport path L in the chamber 100. The +X and -X ends of the chamber 100 have a structure that allows for airtight connection to the openings of other chambers, such as a load-lock chamber or an unload-lock chamber. Each gate 160, 161 has a structure that allows it to be switched open or closed.

[0031] As shown in Figure 1, a high-vacuum evacuation system 170 is connected to the chamber 100. The high-vacuum evacuation system 170 has the function of reducing the gas in the internal space of the chamber 100 to a predetermined process pressure (for example, 0.5 Pa). The high-vacuum evacuation system 170 is electrically connected to the control unit 200 and operates in accordance with commands from the control unit 200. The control unit 200 controls the high-vacuum evacuation system 170 to maintain the pressure in the processing space V at a predetermined process pressure during the film deposition process.

[0032] <Conveying Unit> As shown in Figure 1, the conveying unit 10 has a plurality of conveying rollers 11 and a drive unit (not shown). The plurality of conveying rollers 11 are arranged at intervals along the direction in which the conveying path L extends (X direction). Each conveying roller 11 is composed of a pair of sub-rollers arranged on both sides of the conveying path L in the Y direction. In Figure 1, only the sub-roller on the -Y side of a pair of adjacent sub-rollers in the Y direction is shown. The drive unit is a mechanism that rotates the plurality of conveying rollers 11 in a synchronized manner and includes, for example, an electric motor and a reduction gear. The drive unit is electrically connected to the control unit 200 and operates in response to commands from the control unit 200.

[0033] The base material 91 is detachably held under the carrier 90 by, for example, a claw-shaped member (not shown) provided on the lower surface of the carrier 90. The transfer unit 10 holds the base material 91 such that the film-forming target surface of the base material 91 faces the plasma processing unit 20 side (here, the -Z side). The carrier 90 is constituted by, for example, a plate-like tray. Note that the holding mode of the base material 91 by the carrier 90 is not limited to this. For example, the base material 91 may be held in a state where the lower surface of the base material 91 can be film-formed by fitting the base material 91 into the hollow portion of a plate-like tray having a hollow portion penetrating in the vertical direction.

[0034] When the carrier 90 on which the base material 91 is disposed is carried into the chamber 100 through the gate 160, each transfer roller 11 rotates synchronously to transfer the carrier 90 and the base material 91 along the transfer path L. Each transfer roller 11 can transfer the carrier 90 and the base material 91 in both directions (±X direction).

[0035] The transfer path L includes a film-forming target location P (see FIGS. 1 and 2) facing the plasma processing unit 20. Specifically, the film-forming target location P is a location facing the opening of the chimney 130. Therefore, during the period when the base material 91 transferred by the transfer unit 10 passes through the film-forming target location P, a film-forming process is performed on the film-forming target surface of the base material 91, and during the period when the base material 91 does not pass through the film-forming target location P, the film-forming process on the film-forming target surface of the base material 91 is not performed. Thus, by performing film formation at the film-forming target location P while transferring the base material 91 by the transfer unit 10, continuous film formation can be performed. By repeatedly transferring the base material 91 by the transfer unit 10 in both directions (±X direction), film formation can be performed.

[0036] The gas supply unit 500 supplies a sputtering gas and a reactive gas into the processing space V. The gas supply unit 500 includes a reactive gas supply unit 510 and a sputtering gas supply unit 520.

[0037] The reactive gas supply unit 510 includes a carbon-containing gas supply source 511a, a nitrogen-containing gas supply source 511b, and pipes 512a, 512b, 512c, 512, and 612. One end of pipe 512a is connected to the carbon-containing gas supply source 511a, and one end of pipe 512b is connected to the nitrogen-containing gas supply source 511b. The other ends of pipes 512a and 512b merge at one end of pipe 512c. The other end of pipe 512c then branches into pipe 512 and pipe 612. The other end of pipe 512 branches into multiple pipes, and each branch is connected to a plurality of nozzles 514 that communicate with the processing space V. The other end of pipe 612 also branches into multiple pipes, and each branch is connected to a plurality of nozzles 614 that communicate with the processing space V.

[0038] A valve 513a is provided along the path of the piping 512a. The valve 513a is for adjusting the flow rate of the carbon-containing gas flowing through the piping 512a, and preferably includes a mass flow controller or the like. The valve 513a is electrically connected to the control unit 200 and operates in response to commands from the control unit 200. By adjusting the flow rate of the valve 513a, the amount of carbon-containing gas supplied to the processing space V per unit time is adjusted.

[0039] A valve 513b is provided along the path of the piping 512b. Valve 513b is a valve for adjusting the flow rate of nitrogen-containing gas flowing through the piping 512b, and preferably includes a mass flow controller or the like. Valve 513b is electrically connected to the control unit 200 and operates in response to commands from the control unit 200. By adjusting the flow rate of nitrogen-containing gas with valve 513b, the amount of nitrogen-containing gas supplied to the processing space V per unit time is adjusted. Valves 513a and 513b are examples of flow rate adjustment units.

[0040] A valve 513 is provided along the path of the piping 512. The valve 513 is for adjusting the flow rate of gas flowing through the piping 512 and preferably includes a mass flow controller or the like. The valve 513 adjusts the amount of reactive gas (carbon-containing gas and nitrogen-containing gas) supplied to the processing space V (specifically, near the inductively coupled antenna 151). The valve 513 is electrically connected to the control unit 200 and operates in response to commands from the control unit 200.

[0041] A valve 613 is provided along the path of the piping 612. The valve 613 is for adjusting the flow rate of gas flowing through the piping 612, and preferably includes a mass flow controller or the like. The valve 613 adjusts the amount of reactive gas (carbon-containing gas and nitrogen-containing gas) supplied to the processing space V. The valve 613 is electrically connected to the control unit 200 and operates in response to commands from the control unit 200.

[0042] As shown in Figure 2, the two nozzles 614 are positioned at a height between the transport path L and the chimney 130. The two nozzles 614 are positioned opposite each other in the X direction relative to the opening of the chimney 130. In the illustrated example, in a plan view (i.e., viewed along the Z direction), the two nozzles 614 are positioned so as not to overlap with the opening of the chimney 130. The nozzles 614 may be bar nozzles extending in the Y direction. Multiple discharge ports are formed on the opposing surfaces of the two nozzles 614, spaced apart in the Y direction. The two nozzles 614 discharge reactive gas from each discharge port along the X direction toward the opening of the chimney 130. The discharged reactive gas spreads within the processing space V.

[0043] It is not essential to combine the carbon-containing gas and the nitrogen-containing gas in the piping 512c. In other words, the gas supply unit may be configured to supply the carbon-containing gas and the nitrogen-containing gas independently to the processing space V.

[0044] The sputter gas supply unit 520 includes a sputter gas supply source 521, which is a source of sputter gas, and pipes 522 and 622. One end of pipe 522 is connected to the sputter gas supply source 521, and the other end branches into multiple pipes, each branched end of which is connected to a nozzle 524 provided in the processing space V. Similarly, one end of pipe 622 is connected to the sputter gas supply source 521, and the other end of pipe 622 is connected to multiple nozzles 624.

[0045] In the example shown in Figure 2, the two nozzles 524 are positioned within the chimney 130 at a height between the ceiling surface of the chimney 130 and the upper end of the rotating cathode 30 (described later). The two nozzles 524 are positioned on opposite sides of the opening of the chimney 130 in the X direction. In the illustrated example, in a plan view, the nozzles 524 are positioned so as not to overlap with the opening of the chimney 130. The nozzles 524 may be bar nozzles extending in the Y direction, similar to the nozzle 614. The two nozzles 524 discharge spatter gas from their respective outlets along the X direction toward the opening of the chimney 130. The discharged spatter gas spreads within the processing space V.

[0046] A valve 523 is provided along the path of the piping 522. The valve 523 is for adjusting the flow rate of gas flowing through the piping 522 and preferably includes a mass flow controller or the like. The valve 523 is electrically connected to the control unit 200 and operates in response to commands from the control unit 200. The valve 523 adjusts the amount of sputter gas supplied per unit time to the processing space V.

[0047] As shown in Figure 2, the sputtering apparatus 1 comprises a probe 140 made of optical fiber and a spectrometer 180. The probe 140 is located upstream of the nozzle 524 in the transport path L, at a position away from the -Z side. The spectrometer 180 can measure the spectral intensity of the plasma emission incident on the probe 140. The spectrometer 180 is a sensor that monitors plasma emission spectroscopy and outputs its measured value to the control unit 200. Based on the output of the spectrometer 180, the control unit 200 controls the valve 523 using the plasma emission monitor (PEM) method to adjust the amount (flow rate) of sputtering gas introduced.

[0048] <Plasma Processing Unit> As shown in Figures 1 and 2, the plasma processing unit 20 includes a rotating cathode 30, a rotating drive unit 19, and a sputtering power supply 311 (voltage application unit).

[0049] The rotating cathode 30 functions as an electrode used for sputtering. The rotating cathode 30 is located inside the chimney 130. The rotating cathode 30 is formed in a cylindrical shape and is supported so as to be rotatable around its central axis Q1. The central axis Q1 of the rotating cathode 30 intersects (e.g., perpendicular to) the direction in which the transport path L extends (here, the X direction). In the illustrated example, the central axis Q1 of the rotating cathode 30 is parallel to the Y direction. The rotation drive unit 19 is electrically connected to the control unit 200 and rotates the rotating cathode 30 around the central axis Q1 in response to commands from the control unit 200.

[0050] The rotating cathode 30 includes a base member 31 and a titanium target 32. The base member 31 is formed in a cylindrical shape. The central axis Q1 of the base member 31 is parallel to the Y direction. The base member 31 is a conductor. The titanium target 32 ​​is also formed in a cylindrical shape. The titanium target 32 ​​covers the outer circumference of the base member 31. The outer surface of the titanium target 32 ​​is exposed in the processing space V. Note that if the titanium target 32 ​​is conductive, the base member 31 may be omitted. That is, the rotating cathode 30 may consist only of the titanium target 32 ​​without including the base member 31.

[0051] The plasma processing unit 20 further includes a magnet unit 40. The magnet unit 40 is located inside the rotating cathode 30 and forms a magnetic field near the outer circumferential surface of the titanium target 32. The magnet unit 40 has magnetic pole surfaces 40a and 40b, which face a portion of the inner circumferential surface of the rotating cathode 30 in the circumferential direction. In the illustrated example, the magnet unit 40 is positioned with its magnetic pole surfaces 40a and 40b facing the transport path L side (the +Z side in the illustrated example), so the magnetic pole surfaces 40a and 40b face the region of the inner circumferential surface of the rotating cathode 30 on the transport path L side. This magnet unit 40 forms a magnetic field near that region on the outer circumferential surface of the titanium target 32.

[0052] The rotating cathode 30 is provided so as to be rotatable relative to the magnet unit 40. As the rotating cathode 30 rotates relative to the magnet unit 40, the magnetic field circulates relative to the outer surface of the titanium target 32. In other words, the magnetic field acts around the entire circumference of the titanium target 32.

[0053] The base member 31 and the magnet unit 40 are collectively referred to as a magnetron cathode (cylindrical magnetron cathode). If the base member 31 is not provided, the titanium target 32 ​​and the magnet unit 40 constitute the magnetron cathode.

[0054] In the example shown in Figure 2, the magnet unit 40 includes a yoke 41 (support plate) and a plurality of magnets 43. The yoke 41 is made of a magnetic material such as magnetic steel. The plurality of magnets 43 include a central magnet 43a and peripheral magnets 43b, and are mounted on the yoke 41.

[0055] The yoke 41 is, for example, a flat plate-shaped member and extends in the longitudinal direction (Y direction) of the rotating cathode 30, facing the inner circumferential surface of the rotating cathode 30. A central magnet 43a and peripheral magnets 43b are erected on the main surface (surface) of the yoke 41 facing the inner circumferential surface of the rotating cathode 30. The central magnet 43a extends in the longitudinal direction of the yoke 41 and is positioned on the center line along the longitudinal direction of the yoke 41. The peripheral magnets 43b are provided in an annular (endless) shape surrounding the central magnet 43a at the outer edge of the surface of the yoke 41. The central magnet 43a and peripheral magnets 43b are permanent magnets, such as neodymium magnets.

[0056] The polarities of the magnetic pole surfaces 40a and 40b of the central magnet 43a and the peripheral magnet 43b, respectively, on the titanium target 32 ​​side, are different from each other. For example, the polarity of the magnetic pole surface 40a of the central magnet 43a is the north pole, and the polarity of the magnetic pole surface 40b of the peripheral magnet 43b is the south pole.

[0057] One end of a fixing member 47 is joined to the other main surface (back surface) of the yoke 41. The other end of the fixing member 47 is joined to a support rod 2 that extends along the central axis Q1. Both ends of the support rod 2 extend outward from the rotating cathode 30 and are fixed to the floor surface of the chamber 100 via predetermined support members (not shown). Seal bearings are attached to both ends of the rotating cathode 30 in the Y direction. The rotating cathode 30 is rotatably connected to the support rod 2 via a pair of seal bearings. Each seal bearing is fixed to the floor surface of the chamber 100 via a base 9.

[0058] A base 9 connected to one of the sealed bearings is provided with a rotary drive unit 19, which includes a motor and a gear (not shown) that transmits the rotation of the motor. The rotary cathode 30 is also provided with a gear (not shown) that meshes with the gear of the rotary drive unit 19. The rotary drive unit 19 rotates the rotary cathode 30 around the central axis Q1 by the rotation of the motor. The rotational speed of the rotary cathode 30 is set to, for example, 10 to 20 revolutions per minute, and it rotates at a constant speed at the above rotational speed during the film formation process. The rotary cathode 30 rotates clockwise, for example, in Figure 2.

[0059] The internal space of the rotating cathode 30 is sealed by a pair of seal bearings. The rotating cathode 30 is cooled as appropriate by circulating cooling water through its internal space via the seal bearings and support rod 2.

[0060] The sputtering power supply 311 applies a sputtering voltage to the rotating cathode 30. The wire connected to the sputtering power supply 311 is introduced into the processing space V and guided into the seal bearing of the rotating cathode 30. The end of the wire is provided with a brush that is electrically connected to the base member 31 of the rotating cathode 30. The sputtering power supply 311 applies a sputtering voltage, including a negative voltage, to the base member 31 via this brush. The sputtering voltage is also referred to as the target voltage, cathode applied voltage, or bias voltage.

[0061] The sputtering power supply 311 includes, for example, a switching power supply circuit (not shown). This switching power supply circuit is, for example, a constant voltage type switching power supply circuit, and outputs the sputtering voltage to the rotating cathode 30. The sputtering power supply 311 can output a pulsed sputtering voltage by controlling the switching power supply circuit. The sputtering power supply 311 can control the sputtering voltage by controlling the duty cycle of this pulse. The duty cycle is the ratio of the pulse width to one period of the pulse.

[0062] When a sputtering voltage is applied to the rotating cathode 30, plasma is generated near the outer surface of the rotating cathode 30, particularly in the magnetic field provided by the magnet unit 40. High-energy particles such as ions in this plasma then collide with the titanium target 32, causing titanium particles to be ejected from the titanium target 32 ​​(so-called sputtering). In this way, the plasma processing unit 20 causes titanium particles to be released from the titanium target 32 ​​by imparting energy to it. The plasma processing unit 20 is an example of a "titanium particle emission unit". The titanium particles released from the titanium target 32 ​​react with a reactive gas, and a thin film of the compound is formed on the -Z side surface (film deposition target surface) of the substrate 91.

[0063] As the rotating cathode 30 rotates relative to the magnet unit 40, the magnetic field circulates relative to the outer surface of the titanium target 32, so that sputtering is performed over the entire circumference of the outer surface of the titanium target 32. Therefore, the titanium target 32 ​​can be utilized efficiently. Note that the magnet unit 40 is not required in the sputtering apparatus 1.

[0064] <Inductively Coupled Antennas> The plasma processing unit 20 further includes a pair of inductively coupled antennas 151. As shown in Figure 2, the pair of inductively coupled antennas 151 are embedded in the bottom plate of the chamber 100. One of the pair of inductively coupled antennas 151 is located away from the rotating cathode 30 on the -X side, and the other is located away from the rotating cathode 30 on the +X side. Multiple inductively coupled antennas 151 may be arranged in the Y direction on both the +X and -X sides of the rotating cathode 30. In other words, multiple inductively coupled antennas 151 may be arranged in the Y direction on the -X side of the rotating cathode 30, and multiple inductively coupled antennas 151 may be arranged in the Y direction on the +X side of the rotating cathode 30. Each inductively coupled antenna 151 is covered by a dielectric protective member 152 made of quartz (quartz glass) or the like, and is provided penetrating the bottom plate of the chamber 100.

[0065] Each inductively coupled antenna 151 is, for example, a metal pipe-shaped conductor bent into a U-shape, and is positioned with the U-shape facing inverted vertically, penetrating the bottom plate of the chamber 100 and protruding into the processing space V. The inductively coupled antennas 151 are cooled as appropriate, for example, by circulating cooling water inside.

[0066] One end of each inductively coupled antenna 151 is electrically connected to a high-frequency power supply 153 via a matching circuit 154. The other end of each inductively coupled antenna 151 is grounded. In this configuration, when high-frequency power (for example, 13.56 MHz high-frequency power) is supplied from the high-frequency power supply 153 to the inductively coupled antenna 151, a high-frequency induced magnetic field is generated around the inductively coupled antenna 151, and an inductively coupled plasma (ICP) of sputtered gas and reactive gas is generated in the processing space V. This inductively coupled plasma is also called high-frequency inductively coupled plasma.

[0067] As described above, the inductively coupled antenna 151 has a U-shape. Such a U-shaped inductively coupled antenna 151 corresponds to an inductively coupled antenna with less than one turn, and has a lower inductance than an inductively coupled antenna with one or more turns. Therefore, the high-frequency voltage generated at both ends of the inductively coupled antenna 151 is reduced, and high-frequency fluctuations of the plasma potential associated with electrostatic coupling to the generated plasma are suppressed. As a result, excessive electron loss associated with plasma potential fluctuations relative to ground is reduced, and the plasma potential is kept particularly low. Note that the inductively coupled antenna 151 is not required in the sputtering apparatus 1.

[0068] <Control Unit> The control unit 200 is composed of a computer (for example, a Factory Automation (FA) computer). Specifically, the control unit 200 has a processor such as a CPU (Central Processing Unit) that performs various calculations, a ROM (Read Only Memory) that stores computer programs, a RAM (Random Access Memory) that serves as a workspace for calculations, an auxiliary storage device such as a hard disk that stores computer programs and various data files, a data communication unit that has a data communication function via a LAN (Local Area Network), and a bus line that electrically connects these elements. The control unit 200 is also connected to an output unit such as a display that shows various information, and an input unit such as a keyboard or mouse. In the sputtering apparatus 1, the processor of the control unit 200 executes a computer program, and under the control of the control unit 200, a predetermined film deposition process is performed on the substrate 91.

[0069] <Decorative Film Formation Method> Next, a decorative film formation method for the substrate 91 will be described. The decorative film formation method is a method of decorating the substrate 91 by forming a titanium carbonitride film having a predetermined visible light reflectance on the substrate 91. Visible light reflectance is the ratio of the reflected light flux to the incident light flux when light with a wavelength of 360 nm to 830 nm (visible light) is incident on it. The color of the film can be adjusted by adjusting the visible light reflectance. Figure 3 is a flowchart of the decorative film formation method using the sputtering apparatus 1 shown in Figure 1. Each step shown in Figure 3 is performed under the control of the control unit 200 unless otherwise specified.

[0070] The control unit 200 sets processing conditions based on user input (step S1). Specifically, the quantity of substrates 91 to be processed, the color of the colored substrate (surface color), etc., are set. In the case of sputtering apparatus 1, if several substrates 91 are to be decorated with different surface colors, the respective surface colors and their respective quantities may be set. Also, if thin films are to be laminated, the number of laminations may be set.

[0071] The control unit 200 is configured to accept input of parameters such as Lab value, RGB value, HSL value, or spectral reflectance in order to set the surface color. This allows the user to set the desired surface color by inputting the parameters.

[0072] By increasing or decreasing the ratio of the flow rate of the carbon-containing gas to the flow rate of the nitrogen-containing gas, the proportion of carbon in the titanium carbonitride film formed on the substrate 91 increases or decreases. Depending on this proportion of carbon, the reflectance of the titanium carbonitride film in the visible light wavelength range (400 nm to 800 nm) changes, and the surface color changes. Therefore, the control unit 200 sets the flow rate of the reactive gas so that the surface color (reflected color) of the processed substrate 91 becomes a specified color. The control unit 200 then controls valves 513a and 513b so that the flow rate of the reactive gas becomes a set value.

[0073] The flow rate of the reactive gas corresponding to a specified surface color is determined, for example, by using table data showing the relationship between surface color and flow rate, obtained through experiments or simulations. Such table data is stored in the memory of the control unit 200. Alternatively, a regression model can be used instead of table data. In this case, by using a model that has learned the relationship between surface color and flow rate, the flow rate can be calculated according to the target color. Using a regression model allows for highly accurate estimation of complex color-flow rate relationships, enabling flexible color adjustment.

[0074] After the processing conditions are set, the control unit 200 forms a titanium film as an underlayer on the film-forming surface of the substrate 91 (step S2). Specifically, the substrate 91 is transported toward the film-forming area P by transporting it at a predetermined transport speed. At the same time, the gas supply unit 500 supplies sputtering gas, and the plasma processing unit 20 generates plasma, causing high-energy bodies such as ions to collide with the titanium target 32, thereby releasing titanium particles from the titanium target 32 ​​(sputtering). As the substrate 91 passes through the film-forming area P, the film material is deposited on the film-forming surface of the substrate 91, forming a thin film (titanium film).

[0075] By forming a titanium film underlayer in this manner and then forming a titanium carbonitride film, the adhesion of the titanium carbonitride film to the substrate 91 can be improved. Note that the titanium film may be formed using a device other than the sputtering device 1. Also, the underlayer does not have to be a titanium film; for example, it may be a titanium-aluminum film.

[0076] After the base layer is formed in step S2, the control unit 200 adjusts the flow rate of the reactive gas (step S3). Specifically, the control unit 200 adjusts the flow rate of the carbon-containing gas by controlling valve 513a and the flow rate of the nitrogen-containing gas by controlling valve 513b, according to the conditions set in step S1. This adjusts the flow rate of the carbon-containing gas and the ratio of the flow rate of the carbon-containing gas to the flow rate of the nitrogen-containing gas to be suitable for the specified surface color.

[0077] In step S3, the flow rate of the reactive gas is adjusted, and the titanium carbonitride film deposition process is performed (step S4). Specifically, the substrate 91 is transported toward the deposition site P by transporting it at a predetermined transport speed. The gas supply unit 500 supplies reactive gas and sputtering gas, and the plasma processing unit 20 generates plasma, causing high-energy objects such as ions to collide with the titanium target 32, thereby releasing titanium particles from the titanium target 32 ​​(sputtering). As the substrate 91 passes through the deposition site P, the film material is deposited on the deposition surface of the substrate 91, forming a titanium carbonitride film.

[0078] As described above, the sputtering apparatus 1 makes it easy to decorate the substrate 91 to the desired color by adjusting the flow rate of the carbon-containing gas to match the specified surface color.

[0079] Furthermore, with the sputtering apparatus 1, both the titanium film (the base layer) and the titanium carbonitride film (the decorative layer) can be formed using only the titanium target 32. This reduces the time and effort required for target replacement, thereby improving production efficiency. In addition, it prevents a decrease in color reproducibility due to changes in the chamber environment, enabling the creation of a coating with a stable color.

[0080] <Regarding Color Development> Next, we will explain the color development of the thin films formed on the substrate 91. Here, we will explain the color development when a total of five types of thin films are formed: titanium film (Ti), titanium nitride film (TiN), titanium aluminum nitride (TiAlN), and two types of titanium carbonitride films with different carbon content (TiCN#1, TiCN#2).

[0081] Furthermore, in the formation of TiCN#1 and #2 thin films, the deposition pressure was set to 1 Pa, and the raw material gas was butane gas (C), a carbon-containing gas. ４ H １０ ), nitrogen-containing gas (N ２ The samples used were butane, nitrogen, and argon (Ar) as a sputtering gas. The flow rates for each gas were set to 100 sccm for butane gas in TiCN#1 and 70 sccm for TiCN#2, 140 sccm for nitrogen gas in both samples, and 60 sccm for argon gas in both samples. Note that sccm is a unit representing the gas flow rate per minute under standard conditions (1 atmosphere, 0°C).

[0082] Figure 4A is a graph showing the refractive index n for each of the five types of thin films. Figure 4B is a graph showing the extinction coefficient k for each of the five types of thin films. Figure 4C shows the reflection spectra for each of the five types of thin films. Figure 5 shows the Labs color system for each of the five types of thin films calculated from the reflection spectra.

[0083] The optical constants, refractive index n and extinction coefficient k, were measured by ellipsometry (ISO 23131). The reflectance spectrum R was calculated using the film thickness, the optical constants (n, k), and Fresnel's formula described below.

[0084]

[0085] In each of the above formulas, r p is the amplitude reflectance of the p-wave, t p is the amplitude transmittance of the p-wave, r s is the amplitude reflectance of the s-wave, t s R is the amplitude transmittance of the s-wave. s,p is the energy reflectivity of s-waves and p-waves, T s,p This is the energy transmittance of s-waves and p-waves, N 1、 N2 is the birefringence of the incident and reflected light sides.

[0086] TiAlN is generally used for the purpose of producing blue color. As shown in Figure 4B, focusing on the extinction coefficient k, TiAlN falls within the range of 0.5 to 1.0, which is lower and less variable in the visible light region compared to other Ti and TiN materials. It is thought that by reproducing optical constants equivalent to those of TiAlN, it will be possible to produce blue color with a titanium target.

[0087] Here, we confirmed that optical constants similar to those of TiAlN can be reproduced by adding carbon C to TiN. For example, as shown in Figure 4B, in TiCN#2 with a small butane gas supply, the extinction coefficient k is higher than that of TiCN#1, similar to the trend of the extinction coefficient k of TiAlN. Also, as shown in Figure 4C, the reflectance spectrum of TiCN#2 is similar to the trend of the reflectance spectrum of TiAlN.

[0088] Furthermore, the average reflectance (average value of reflectance obtained in 10 nm increments) in the long-wavelength region (ranging from 600 nm to 800 nm) of TiCN#1 and TiCN#2 is lower than the average reflectance in the short-wavelength region (ranging from 400 nm to 600 nm) and also lower than the average reflectance in the blue-wavelength region (ranging from 400 nm to 500 nm). In addition, the average reflectance in the long-wavelength region is 20% or less. In particular, the average reflectance of the long-wavelength bubbles of TiCN#1 is 10% or less, which is smaller than that of TiAlN and TiCN#2. This is reflected in the magnitude of the b value in the Lab value, where the b value of TiCN#1 is larger on the negative side than the b value of TiAlN.

[0089] In terms of Lab values, TiAlN is positioned between TiCN#1 and TiCN#2. From this, we were able to confirm that the blue hue can be adjusted by increasing or decreasing the amount of carbon added, and that the Lab value can be made to match that of TiAlN to a similar extent.

[0090] <2. Modifications> Although embodiments have been described above, the present invention is not limited to those described above, and various modifications are possible.

[0091] For example, the decorative film deposition apparatus releases titanium particles from the titanium target 32 ​​by sputtering, by imparting energy from ions generated by plasma to the titanium target 32. However, the release of titanium particles can also be achieved by other methods. For example, titanium particles can be released by imparting energy by heating, such as in vacuum deposition, or by imparting energy by arc discharge, such as in arc ion plating.

[0092] Although this invention has been described in detail, the above description is illustrative in all respects, and the invention is not limited thereto. It is understood that countless variations not illustrated can be conceived without falling outside the scope of this invention. The components described in each of the above embodiments and variations can be combined or omitted as appropriate, as long as they do not contradict each other.

[0093] 1: Sputtering apparatus (decorative film deposition apparatus) 10: Transport section 20: Plasma processing section (titanium particle emission section) 32: Titanium target 91: Substrate 100: Chamber 200: Control section 500: Gas supply section 513a: Valve (flow rate adjustment section) 513b: Valve (flow rate adjustment section) 520: Sputter gas supply section

Claims

1. A decorative film deposition apparatus for performing a film deposition process on a substrate, comprising: a chamber; a titanium particle release unit including a titanium target disposed in the chamber and for releasing titanium particles by applying energy to the titanium target; a gas supply unit connected to the chamber and for supplying a reactive gas; and a control unit for controlling the gas supply unit, wherein the gas supply unit comprises: a carbon-containing gas supply unit for supplying a carbon-containing gas containing carbon atoms into the chamber; a nitrogen-containing gas supply unit for supplying a nitrogen-containing gas containing nitrogen atoms into the chamber; and a flow rate adjustment unit capable of adjusting the flow rate of the carbon-containing gas with respect to the flow rate of the nitrogen-containing gas, and the control unit adjusts the flow rate of the carbon-containing gas by the flow rate adjustment unit to adjust the visible light reflectance of the film formed on the object to be deposited.

2. A decorative film deposition apparatus according to claim 1, wherein the titanium particle emission unit comprises a cathode containing the titanium target and a voltage application unit for applying a voltage to the cathode, and the gas supply unit further comprises a sputtering gas supply unit for supplying sputtering gas for sputtering the titanium target into the chamber.

3. A decorative film deposition apparatus according to claim 2, further comprising a transport unit that transports a substrate relative to the titanium target so as to pass around the titanium target within the chamber.

4. A decorative film formation method for forming a film on a substrate, comprising: a step of placing the substrate in a chamber; a titanium release step of applying energy to a titanium target placed in the chamber to release titanium; a gas supply step of supplying gas into the chamber; and a control step of controlling the flow rate of the gas supplied into the chamber by the gas supply step, wherein the gas supply step comprises supplying a carbon-containing gas containing carbon atoms and a nitrogen-containing gas containing nitrogen atoms into the chamber; and the control step comprises adjusting the flow rate of the carbon-containing gas to adjust the visible light reflectance of the film formed on the object to be formed.

5. A decorative substrate comprising: a substrate; and a titanium carbonitride film formed on the substrate, wherein the titanium carbonitride film has an average reflectance in the wavelength range of 600 nm to 800 nm that is smaller than the average reflectance in the wavelength range of 400 nm to 500 nm.

6. The decorative substrate according to claim 5, wherein the average reflectance of the titanium carbonitride film in the wavelength range of 600 nm to 800 nm is 20% or less.

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