JP2008240093A - Reflector and method for manufacturing the reflector - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a reflector which can exhibit various hues based on changes of deposition conditions by adequate combinations of reflection films and light transparent films and to provide a method for manufacturing the same. <P>SOLUTION: The reflector R includes a substrate 20, a reflection film 22 composed of titanium nitride on the substrate 20 and a light transparent film 23 composed of titanium oxide on the reflection film 22, and is constituted in such a manner that the hue of the light reflected by the reflection film 22 can be changed based on the thickness of the light transparent film 23, the composition ratio of the titanium nitride and the composition ratio of the titanium oxide. <P>COPYRIGHT: (C)2009,JPO&INPIT

Description

  The present invention relates to a reflector and a method for manufacturing the reflector.

  The vacuum film formation technique is often used for forming functional films for industrial products, but is not limited to this, and can also be used for forming decorative films for personal products.

  For example, a decorative film made of titanium oxide is formed on an aluminum film (reflective film) by a vacuum process, and various hues are created by changing the thickness of this decorative film and the oxidation degree (composition ratio) of titanium oxide. (See Patent Document 1 and Patent Document 2).

  There is also a prior art that describes that the hue of light transmitted from a laminate of a titanium nitride film and a titanium oxide film formed by a vacuum process can be adjusted by the thickness of these films (see Patent Document 3).

In addition, there is a prior art that describes that a titanium oxide film (translucent film) is formed on a titanium reflective film or a chrome reflective film by a vacuum process, and various hues are produced by the thickness of the translucent film (patent) (Ref. 4)
In addition, there is a prior art that describes that the titanium nitride film after heat treatment can have various colors by changing the composition ratio of titanium and nitrogen in the titanium nitride when the titanium nitride film is formed by a vacuum process (patent) Reference 5).
JP 2001-337212 A JP 2001-262316 A JP-A-2-44046 JP 2002-274101 A Japanese Patent Laid-Open No. 7-207446

  By the way, as a result of diligent research, the present inventors have found that a reflective film made of titanium nitride (hereinafter abbreviated as “titanium nitride film”) and a translucent film made of titanium oxide (hereinafter abbreviated as “titanium oxide film”) It has been found that a reflector that greatly expands the hue range than the above-described prior art can be efficiently obtained by combining the above. For example, it has been found that such a reflector can easily produce a bright hue from orange to red based on the interaction between the reflection characteristics of the titanium nitride film and the reflection characteristics of the oxygen-deficient titanium oxide film. .

  The present invention has been made in view of such circumstances, and a reflector capable of exhibiting various hues based on changes in the film forming conditions by an appropriate combination of a reflective film and a translucent film. And it aims at providing the manufacturing method of a reflector.

  First, the results of evaluating the spectral reflectance of a titanium nitride film or a titanium oxide film will be described. Various reflectance data described below are measured with a spectrophotometer ("U-4100" manufactured by Hitachi).

  FIG. 1 is a diagram comparing the reflection characteristics of a titanium nitride film with the reflection characteristics of a titanium film. In FIG. 1, the spectral reflectance of the titanium nitride film is indicated by a solid line, and the spectral reflectance of the titanium film is indicated by a broken line.

  As shown in FIG. 1, the reflectance in the visible region is constant in the titanium film exhibiting a silver metallic luster, whereas the reflectance on the short wavelength side in the visible region in the titanium nitride film exhibiting the gold color. Is low.

FIG. 2 is a diagram illustrating reflection characteristics based on various thicknesses of a titanium oxide film of a reflector (TiN / TiO _x reflector) composed of a titanium nitride film (reflection film) and a titanium oxide film (translucent film). It is.

For example, in FIG. 2, the thickness of the titanium oxide film is 150 mm (thick broken line; brown), 450 mm (thick solid line; light blue), 750 mm (thin broken line; light gray), 1050 mm (thin dotted line; light orange), The spectral reflectance of the TiN / TiO _x reflector is illustrated for 1350Å (thick two-dot chain line; purple), 1650Å (thick one-dot chain line; pale green), and 2000Å (thin solid line; skin color).

  As can be easily understood from FIG. 2, the spectral reflection characteristic of the reflector can be changed by adjusting the thickness of the titanium oxide film. Note that, due to the effect of the reflection characteristics of the titanium nitride film described above, the peak of the spectral reflectance of the reflector shown in FIG. 2 becomes lower from the long wavelength side to the short wavelength side in the visible range.

FIG. 3 shows the reflection characteristics of the TiN / TiO _x reflector (150 Å) when the thickness of the titanium oxide film is 150 mm (see the broken line in FIG. 3), and the reflector of the titanium reflector film (Ti / TiO _x reflector). It is the figure compared with the reflection characteristic of.

In FIG. 3, the spectral reflectance of the Ti / TiO _x (150 Å) reflector when the thickness of the titanium oxide film is 150 で is indicated by a solid line. Further, the spectral reflectance of Ti / TiO _x (300 mm) when the thickness of the titanium oxide film is 300 mm is indicated by a one-dot chain line.

According to FIG. 3, the TiN / TiO _x (150 （) reflector and the Ti / TiO _x (150Å) reflector exhibit completely different hues, whereas the TiN / TiO _x (150Å) reflector and Ti It can be seen that the / TiO _x (300Å) reflector exhibits a similar hue (brown here). Therefore, the thickness of the titanium oxide film in the TiN / TiO _x (150 （) reflector is half the thickness of the titanium oxide film in the Ti / TiO _x (300Å) reflector in order to produce a brown hue. . In addition, although description is abbreviate | omitted here, the same tendency exists also in hues other than brown type.

  Summarizing the evaluation results of the reflection characteristics listed above, the following conclusions can be obtained.

  First, if a titanium nitride film is used as a reflective film instead of a titanium film, the reflectivity of purple to green hues will be kept low, and it will be possible to easily produce vivid hues of orange to red hues. it can.

Here, it is said that the transmissivity of the titanium oxide film whose composition ratio is oxygen deficient titanium oxide “hereinafter abbreviated as“ oxygen deficient titanium oxide film ”” also has a lower reflectance on the short wavelength side. (See Patent Document 1 above). For this reason, when an oxygen-deficient titanium oxide film is formed on the titanium nitride film, the reflectance on the short wavelength side can be appropriately and sufficiently lowered due to the interaction between both reflection characteristics. As a result, as a decorative use, a reflector exhibiting a bright hue from orange to red can be appropriately produced. In this specification, the term "oxygen deficiency type titanium oxide", of the composition formula "TiO _X", the composition ratio of oxygen to titanium value is less than "2" in the "x" (x <2) It shall refer to a certain titanium oxide material.

  Second, when a titanium nitride film is used as a reflective film, it can be determined that a reflector exhibiting a different hue can be efficiently obtained by changing the thickness of the titanium oxide film. In other words, the thickness of the titanium oxide film when the titanium nitride film is used as the reflective film can be made thinner than the thickness of the titanium oxide film when the titanium film is used as the reflective film. Efficiency can be improved.

  Here, when the composition ratio between titanium (Ti) and nitrogen (N) in titanium nitride is changed, a different hue, such as a golden hue, a copper hue, or a hue close to purple or black, is reflected on the reflector. (See the above-mentioned Patent Document 5). For this reason, a reflector capable of exhibiting various hues can be obtained by cooperation between the adjustment of the thickness of the titanium oxide film and the adjustment of the composition ratio of titanium nitride, which is preferable.

  The present invention has been devised on the basis of the knowledge described above, and includes a substrate, a reflective film made of titanium nitride formed on the substrate, and a titanium oxide formed on the reflective film. And the hue of the light reflected by the reflection film can be changed based on the thickness of the light transmission film, the composition ratio of the titanium nitride, and the composition ratio of the light transmission film. A reflector configured as described above is provided.

  Thereby, a reflector that greatly expands the hue range can be obtained by selecting film forming conditions such as the thickness of the light transmissive film, the composition ratio of titanium nitride, and the composition ratio of the light transmissive film.

  The translucent film may be made of oxygen-deficient titanium oxide.

  Thus, the reflector appropriately exhibits a bright hue from orange to red based on the interaction between the reflection characteristics of the titanium nitride film and the reflection characteristics of the oxygen-deficient titanium oxide film.

  The present invention also includes a substrate disposed in a vacuum chamber, a reflective film made of titanium nitride formed on the substrate, and a translucent film made of titanium oxide formed on the reflective film. A method for manufacturing a reflector configured to change the hue of light reflected by the reflective film based on the thickness of the light-transmitting film, the composition ratio of the titanium nitride, and the composition ratio of the titanium oxide A step of forming a discharge plasma in the vacuum chamber; and a discharge plasma between titanium and nitrogen gas sputtered from a target in the vacuum chamber by adding nitrogen gas into the vacuum chamber. Based on the reaction, the step of forming the reflective film on the substrate, and the addition of oxygen gas into the vacuum chamber allows the reflective film to be based on a discharge plasma reaction between the titanium and oxygen gas. Up To provide a method of manufacturing a reflector including the steps of forming said transparent film.

  Thus, a reflector manufacturing method can be obtained that greatly expands the hue range by selecting film forming conditions such as the thickness of the translucent film, the composition ratio of titanium nitride, and the composition ratio of titanium oxide.

  In the step of forming the translucent film, the discharge state of the sputtering may be controlled to a transition region.

  Thereby, speeding up of the translucent film formation by sputtering can be achieved.

  Further, the amount of the oxygen gas added may be adjusted based on the light intensity of the spectrum emitted from titanium in the discharge plasma in the transition region.

  As a result, the film quality of the light-transmitting film can be stabilized in the reactive sputtering transition region.

  The present invention has a configuration described above, and a reflector and a reflector that can exhibit various hues based on changes in the film formation conditions by an appropriate combination of a reflective film and a light-transmitting film. There is an effect of providing a manufacturing method.

  First, a schematic configuration of a vacuum film forming apparatus (sputtering apparatus) for manufacturing the reflector according to the present embodiment will be described with reference to the drawings.

  FIG. 4 is a schematic view showing a main part of a sputtering apparatus used for manufacturing the reflector according to the embodiment of the present invention. In addition, in FIG. 4, the mode inside the vacuum chamber 10 of the sputtering device 100 is planarly viewed from the action direction of gravity.

  The sputtering apparatus 100 of this embodiment includes a vacuum chamber 10 having a space P that can be depressurized. A vacuum pump (not shown) for evacuating the inside P of the vacuum chamber 10 through an opening (not shown) in the wall of the vacuum chamber 10 is arranged. If the inside of the vacuum chamber 10 in a vacuum state is opened to the atmosphere by an appropriate leak valve (not shown), the inside P of the vacuum chamber 10 can be accessed by opening and closing the door 12.

Further, as shown in FIG. 4, the sputtering apparatus 100 has an argon gas supply means (for example, an argon gas supply source valve) capable of guiding argon gas (Ar gas) as a discharge gas to the inside P of the vacuum chamber 10. ₂ ), an oxygen gas supply means 16 (for example, an oxygen gas supply source valve) capable of introducing oxygen gas (O ₂ gas) as the first reaction gas to the inside P of the vacuum chamber 10, and the inside of the vacuum chamber 10 Nitrogen gas supply means 17 (for example, a nitrogen gas supply source valve) capable of introducing nitrogen gas (N ₂ gas) as the second reaction gas to P. In FIG. 4, an oxygen gas supply means 16 and a nitrogen gas supply means 17 for a central target 11 (described later) facing the door 12 are shown. A gas supply means (not shown) is also provided.

A plurality of (here, three) plate-like targets 11 made of titanium (Ti) are disposed at appropriate positions on the inner side wall surface of the vacuum chamber 10. A turntable 14 (substrate holder) on which the substrate 20 can be placed and rotated is disposed on the bottom wall inside the vacuum chamber 10. The above-mentioned target 11 is a thin film base material deposited on the substrate 20 and becomes a cathode by a DC constant power source (not shown) for the purpose of forming an electric field that attracts ions (Ar ⁺ ) in the discharge plasma. So that constant power is supplied. The grounded vacuum chamber 10 is connected to the anode side of the constant power source.

Although not shown, a magnetic field generating means composed of a plurality of magnets is arranged on the back surface of the target 11, and a predetermined leakage magnetic field is formed in the vicinity of the surface of the target 11 by magnetic lines generated by these magnets. Yes. In this state, when the argon gas is introduced into the inside P of the vacuum chamber 10 by the argon gas supply means, an Ar gas discharge (magnetron discharge) is caused by the action of the tunnel-like leakage magnetic field for confining the discharge plasma and the above-described electric field. ) Occurs. For this reason, a high-density discharge plasma 13 composed of a large number of charged particles (Ar ⁺ and electrons) is formed near the surface of the target 11.

  Further, when the sputtering apparatus 100 deposits a titanium nitride film 22 and a titanium oxide film 23 (both described later) on the substrate 20 by reactive sputtering, the light intensity emitted from titanium in the discharge plasma 13 is changed to an optical fiber. The spectroscope 31 which can be detected using 32 is provided. In FIG. 4, the optical fiber 32 and the spectroscope 31 for the center target 11 facing the door 12 are illustrated, but actually, an optical fiber and a spectroscope (not shown) for the two left and right targets 11 are illustrated. A bowl is also provided.

  The control device 30 of the sputtering apparatus 100 includes, for example, a microprocessor, an arithmetic processing unit including a CPU, a storage unit including a memory such as a ROM and a RAM, an output unit such as a display monitor, and an operation such as a keyboard. It has an input part (all are not shown). The arithmetic processing unit reads a predetermined control program stored in the storage unit, and performs various controls relating to the sputtering apparatus 100 based on the control program.

  For example, the control device 30 uses the oxygen gas supply means 16 to appropriately adjust the flow rate (addition amount) of oxygen gas supplied to the sputtering device 100 so that the titanium oxide film 23 can be deposited at high speed. The operation of the sputtering apparatus 100 can be controlled. Detailed operation contents of the sputtering apparatus 100 will be described later.

  In this specification, the control device means not only a single control device but also a control device group in which a plurality of control devices cooperate to execute control of the film forming device. For this reason, the control device does not need to be configured by a single control device, and a plurality of control devices may be arranged in a distributed manner so as to control the film forming apparatus in cooperation with each other.

  Next, the operation of the sputtering apparatus 100 of this embodiment will be described with reference to FIGS. 4 and 5.

  FIG. 5 is a cross-sectional view illustrating a configuration example of the reflector according to the present embodiment. According to FIG. 5, a titanium nitride film 22 and a titanium oxide film 23 are formed on the substrate 20 in this order.

  First, in a state where the discharge plasma 13 is formed in the vacuum chamber 10, nitrogen gas is introduced into the interior P of the vacuum chamber 10 by the nitrogen gas supply means 17, and the interior P of the vacuum chamber 10 has a desired vacuum. It becomes a state.

Then, Ar ⁺ is attracted to the target 11 by the action of the constant power electric field applied to the target 11 from the constant power source. Thereby, the constituent atoms (titanium in this case) of the target 11 are knocked out from the surface of the target 11 by the collision energy of Ar ⁺ . This titanium becomes titanium nitride after reacting with the nitrogen gas activated by the discharge plasma 13. Then, the titanium nitride film 22 is deposited on the substrate 20 to a desired thickness that can appropriately exhibit its reflecting function. The thickness of the titanium nitride film 22 is controlled by the film formation time.

  In this sputtering process, the composition ratio between titanium (Ti) and nitrogen (N) in titanium nitride is adjusted by adjusting the amount of nitrogen gas added to the inside P of the vacuum chamber 10 by the nitrogen gas supply means 17. Can be changed.

  Next, the introduction of nitrogen gas into the interior P of the vacuum chamber 10 is stopped by the nitrogen gas supply means 17, and the oxygen gas is introduced into the interior P of the vacuum chamber 10 by the oxygen gas supply means 16, and the vacuum chamber The inside P of 10 becomes a desired vacuum state. For example, the control device 30 uses the oxygen gas supply means 16 to control the amount of oxygen gas added so that the reactive sputtering discharge state is in a transition region (described later). Thereby, the sputtering process of the titanium oxide film 23 can be speeded up. In reactive sputtering, it is known that as the amount of oxygen gas added increases, the metal mode deposits at a high rate metal mode and the oxide film is deposited at a low rate reactive mode. It has been. Such a mode in which the film quality easily changes between the metal mode and the reactive mode is called a transition region. That is, in the present embodiment, sputtering in such a transition region is positively used for the purpose of increasing the deposition rate of the reactive sputtering of the titanium oxide film 23.

  The titanium described above becomes titanium oxide after reacting with the oxygen gas activated by the discharge plasma 13 in the transition region of reactive sputtering. Thereby, the titanium oxide film 23 can be deposited at a high speed on the substrate 20 (precisely on the titanium nitride film 22) to a desired thickness corresponding to a desired hue. The thickness of the titanium oxide film 23 is controlled by the film formation time.

  During the sputtering process, the spectroscope 31 obtains a spectral spectrum of light emitted from titanium. The controller 30 supplies oxygen gas supply means so that the light intensity is constant based on the light intensity of the spectrum having the wavelength that governs the characteristics of the titanium oxide film 23 among the spectrum dispersed by the spectroscope 31. 16 is used to control the amount of oxygen gas added. Thereby, the film quality of the titanium oxide film 23 can be stabilized in the reactive sputtering transition region.

  Moreover, in the transition region of reactive sputtering, the composition ratio of titanium oxide can be easily changed. As a result, an oxygen-deficient titanium oxide film can be formed on the substrate 20.

  Here, the reactive sputtering of the titanium oxide film 23 whose deposition rate is extremely slow compared with the titanium nitride film 22 is exemplified in the transition region, but the reactive sputtering of the titanium nitride film 22 is also performed. You may perform in a transition area | region by the method described above.

  Thus, a reflector R comprising the titanium nitride film 22 (reflective film) formed on the substrate 20 and the titanium oxide film 23 (translucent film) formed on the titanium nitride film 22 is obtained. It is done.

Thereby, in this Embodiment, the hue of the reflector R can be changed based on the thickness of the titanium oxide film 23. Further, the hue of the reflector R can be changed based on the composition ratio of titanium nitride. Further, the hue of the reflector R can be changed based on the composition ratio of titanium oxide. Therefore, various hues can be created in the reflector R based on the change of these film forming conditions. In particular, as described above, due to the interaction between the reflection characteristics of the titanium nitride film 22 and the reflection characteristics of the oxygen-deficient titanium oxide film, the reflector R can exhibit a bright hue from orange to red, It is suitable as a decorative use.
(Modification)
The reflector R of the present embodiment includes a titanium nitride film 22 (reflection film) formed on the substrate 20 and a titanium oxide film 23 (translucent film) formed on the titanium nitride film 22. Although it has a laminated structure, this is only an example until it gets tired. This reflector can be modified into various laminated structures.

For example, as shown in FIG. 6, the reflector R1 of this modification includes a mixed film 21 (Ti / TiO _x mixed film 21) made of titanium and titanium oxide formed on the substrate 20, and this Ti / TiO _x. A titanium film 24 formed on the mixed film 21, a titanium nitride film 22 (reflective film) formed on the titanium film 24, and a titanium oxide film 23 (translucent film) formed on the titanium nitride film 22 And may be provided.

According to such a reflector R1, the adhesion between the substrate 20 and the titanium film 24 or the titanium nitride film 22 is sometimes improved by the action of the Ti / TiO _x mixed film 21, which may be beneficial.

Since the uppermost layer of the laminated structure of the reflector R1 is the titanium oxide film 23, titanium oxide as an impurity (oxide film) is formed on the surface of the titanium target 11 at the end of the production of the reflector R1. It is thought that it is deposited. For this reason, if the pre-sputtering (impurity removing process of the target 11) of the sputtering apparatus 100 in the next production of the reflector R1 is used well, the oxygen gas can be put on the substrate 20 without introducing oxygen gas into the vacuum chamber 10 of the sputtering apparatus 100. The Ti / TiO _x mixed film 21 can be easily formed.

  The reflector of the present invention can exhibit various hues based on changes in the film formation conditions by an appropriate combination of a reflective film and a light-transmitting film, and can be used, for example, as a product decoration application. .

It is the figure compared with the reflective characteristic of a titanium film about the reflective characteristic of a titanium nitride film. It is the figure which illustrated the reflective characteristic based on various thickness of the titanium oxide film of the reflector which consists of a combination of a titanium nitride film (reflection film) and a titanium oxide film (translucent film). It is the figure which compared the reflective characteristic of the reflector in FIG. 2 whose thickness of a titanium oxide film is 150 mm with the reflective characteristic of the reflector used for the titanium film (reflective film). It is the schematic diagram which showed the principal part of the sputtering device used for manufacture of the reflector of embodiment of this invention. It is sectional drawing which showed one structural example of the reflecting plate of this embodiment. It is sectional drawing which showed the other structural example of the reflecting plate of this embodiment.

Explanation of symbols

DESCRIPTION OF SYMBOLS 10 Vacuum chamber 11 Target 12 Door 13 Discharge plasma 14 Turntable 16 Oxygen gas supply means 17 Nitrogen gas supply means 20 Substrate 22 Titanium nitride film 23 Titanium oxide film 30 Control device 31 Spectroscope 32 Optical fiber 100 Sputtering device

Claims (5)

A substrate, a reflective film made of titanium nitride formed on the substrate, and a translucent film made of titanium oxide formed on the reflective film,
A reflector configured to change a hue of light reflected by the reflective film based on a thickness of the light-transmitting film, a composition ratio of the titanium nitride, and a composition ratio of the titanium oxide.   The reflector according to claim 1, wherein the translucent film is made of oxygen-deficient titanium oxide. A substrate disposed in a vacuum chamber; a reflective film made of titanium nitride formed on the substrate; and a light-transmitting film made of titanium oxide formed on the reflective film; Based on the thickness, the composition ratio of the titanium nitride, and the composition ratio of the titanium oxide, a method of manufacturing a reflector configured to be able to change the hue of light reflected by the reflective film,
Forming a discharge plasma in the vacuum chamber;
Forming the reflective film on the substrate based on a discharge plasma reaction between titanium and nitrogen gas sputtered from a target in the vacuum chamber by adding nitrogen gas into the vacuum chamber; ,
Forming the translucent film on the reflective film based on a discharge plasma reaction between the titanium and the oxygen gas by adding oxygen gas into the vacuum chamber;
The manufacturing method of the reflector containing this.   The method of manufacturing a reflector according to claim 3, wherein in the step of forming the translucent film, a discharge state of the sputtering is controlled to a transition region.   The method for manufacturing a reflector according to claim 4, wherein the addition amount of the oxygen gas is adjusted based on a light intensity of a spectrum emitted from titanium in the discharge plasma in the transition region.

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