JP4184498B2 - Zinc / indium BM film and BM film manufacturing method - Google Patents

Description

[0001]
BACKGROUND OF THE INVENTION
The present invention relates to a low reflection BM film (black matrix film) used for a color display element such as a liquid crystal, and a method for producing the BM film.
[0002]
[Prior art]
In recent years, color liquid crystal displays have been actively produced and used for notebook computers and car navigation systems.
In a color liquid crystal display, a color filter (CF) as an essential component as indicated by reference numeral 100 in FIG.
[0003]
In general, the color filter 100 has red, green, and blue color filter layers 103 ₁ , 103 ₂ , and 103 ₃ formed on a glass substrate 101, and a transparent conductive film 106 patterned through a protective film 105 on the surface thereof. Is formed so that a voltage can be applied to the liquid crystal disposed on the transparent conductive film 106.
[0004]
Between each of the color filter layers 103 _{1 to} 103 ₃ , a black matrix (BM) film 102 is disposed for improving the contrast of color display, reducing external light reflection, and improving visibility.
[0005]
Such a BM film 102 is required to have a low reflection and a high light-shielding property, and there are various materials such as a resin film and a metal reflection layer. A BM film having a laminated structure composed of a transparent light-transmitting layer and a metal reflecting layer is used.
[0006]
As a BM film having a laminated structure, a chromium-based laminated film in which a translucent CrOx thin film is formed on a glass substrate to form a translucent layer, and a metal chromium thin film is continuously formed on the surface to form a metal reflecting layer is widely used. It is used.
[0007]
In such a chromium-based laminated BM film, the reflected light at the interface between the CrOx thin film and the glass substrate interferes with the reflected light at the interface between the CrOx thin film and the metal chromium thin film, and an antireflection effect is obtained. Thus, a large reduction in reflection is achieved.
[0008]
However, when the interference effect is used, the wavelength dependence of the reflectance spectrum greatly affects the interference effect. As a result, there is a problem that the BM film having a two-layer structure is slightly colored.
[0009]
In order to eliminate such coloring and make the hue closer to black, a BM film in which three or more thin films are stacked may be used. In the case of a BM film having a multilayer structure, a translucent layer is formed by laminating a plurality of translucent thin films, so that the refractive index of each thin film is changed in the film thickness direction, and a high interference effect is obtained in a wide wavelength range. Accordingly, coloring can be prevented and the BM film can be further blackened.
[0010]
Conventionally, as such a BM film having a multilayer structure, a BM film in which a light-transmitting layer is formed by changing the degree of oxidation of a chromium thin film, such as Cr / CrOy / CrOx, or a reaction such as Cr / CrNy / CrOx, is used. There is a BM film in which a kind of reactive gas is changed and a nitride thin film and an oxide thin film are laminated to form a light-transmitting layer.
[0011]
However, since all of the BM films having the above-described laminated structure use a metal chromium thin film or a light-transmitting layer made of a chromium compound, when patterning the BM film by wet etching, harmful substances such as hexavalent chromium are contained in the waste liquid. It has been pointed out that the substance may elute and cause pollution problems.
[0012]
In addition, since thin films such as a metal chromium thin film and a CrOx film have relatively high stress and are easily peeled off, when the BM film is formed by a sputtering method, the thin film adheres to a deposition plate or the like in the sputter deposition chamber. It peeled off, causing the generation of particles.
[0013]
[Problems to be solved by the invention]
The present invention was created to solve the above-described disadvantages of the prior art, and an object of the present invention is to provide a BM film with low pollution and less particle generation, and a method for manufacturing the BM film.
[0014]
[Means for Solving the Problems]
In order to solve the above-mentioned problem, the invention according to claim 1 is a BM film having a light-transmitting layer formed on a glass substrate and a metal reflecting layer formed on the light-transmitting layer, the main component of the metal reflective layer, Ri either one der indium or zinc, the transparent layer is that it has a nitride film on the basis of either the nitride or nitrides of zinc indium Features .
[0015]
The invention according to claim 2 is a BM film having a light-transmitting layer formed on a glass substrate and a metal reflecting layer formed on the light-transmitting layer, and the main component of the metal reflecting layer is: Ri either one der indium or zinc, the transparent layer is characterized by having an oxide film on the basis of either the oxide or zinc indium.
[0016]
Invention of Claim 3 is a BM film | membrane manufacturing method which manufactures BM film | membrane of any one of Claim 1 or Claim 2 , Comprising : Sputtering gas and oxygen gas of the pressure of 1 * 10 ^<-2 > Pa or less The metal indium thin film is formed by sputtering a target containing indium as a main component in a sputtering atmosphere containing a metal.
[0018]
This invention is comprised as mentioned above and is a BM film | membrane of the laminated structure which consists of a metal reflective layer and a translucent layer.
[0019]
The reflectance characteristics of the BM film having such a laminated structure will be described. For example, as shown in FIG. 5A, a translucent layer (oxide thin film or nitride thin film) 54 made of a translucent metal compound, When the BM film 51 having a two-layer structure including the reflective metal reflective layer 55 is laminated on the glass substrate 52, the light 60 incident on the BM film 51 from the direction of the glass substrate 52 In addition to being reflected at the interface 57 of the translucent layer 54 and returning as reflected light 61 in the incident direction, the light 60 transmitted through the translucent layer 54 is reflected at the interface 58 between the translucent layer 54 and the metal reflective layer 55. The reflected light 62 is returned in the incident direction.
[0020]
Accordingly, two types of reflected light 61 and 62 are returned in the incident direction, but when the light-transmitting layer 54 has appropriate (transparency), the light intensity R of the two types of reflected light 61 and 62 is reflected. ₁ and R ₂ are R ₁ ≈R ₂ , and when the phases are inverted, the intensity of the reflected light 61 and 62 is attenuated by the interference of the two reflected lights 61 and 62, and the BM film 51 is reduced in reflection.
[0021]
On the other hand, when the transparency of the translucent layer 54 is high and the refractive index is too small, R ₁ >> R ₂ , and conversely, when the refractive index is too large, R ₁ << R ₂ . A sufficient interference effect cannot be obtained.
[0022]
Further, as shown in FIG. 5B, the light-transmitting layer 74 of the BM film 71 includes the first thin film 74 ₁ formed on the glass substrate 72 and the second layer formed on the surface thereof. If the thin film 74 _2, further comprising a metal reflective layer 75. which is formed on the thin film 74 ₂ of the second layer, the light 80 incident from the glass substrate 72 side is reflected by the interfaces, three types of Reflected light 81, 82, 83 is reflected in the incident direction, and low reflection is achieved by their multiple interference effect.
[0023]
In the case of such a three-layer BM film, the interference balance of the reflected lights 81 to 83 is optimized (the refractive index of the first light-transmitting layer 74 is set to the refractive index of the second light-transmitting layer 75). When compared with a BM film having a two-layer structure, the wavelength dependence of the reflectance value is small, and a black BM film can be obtained with lower reflection.
[0024]
As described above, when the BM film of the laminated structure, it is necessary to adjust the refractive index of the transparent layer 54, 74, oxidizing gas depending on the target to be used (O _2, CO _2), nitriding It is necessary to obtain a desired refractive index by appropriately combining gas (N ₂ ) and reducing gas (H ₂ , CxHy).
[0025]
In any case, the BM film of the present invention uses a metal oxide thin film or metal nitride thin film having an appropriate refractive index without using chromium, and forms a low reflectivity laminated film. A non-polluting BM film with reflectivity is obtained.
[0026]
DETAILED DESCRIPTION OF THE INVENTION
The BM film of the present invention will be described together with its manufacturing method.
For the production of the BM film, a load lock type sputtering apparatus of a horizontal substrate transport system was used. The substrate is a 210 mm × 210 mm × 1.1 mm thick glass substrate (Corning # 7059), the target is a metal zinc target or an indium alloy target (In-5 wt% Sn), and a direct current magnetron sputtering method is used. Film formation was performed.
[0027]
The sputtering gas was an argon gas, and the sputtering atmosphere was a pressure of 0.67 Pa. The substrate during sputtering was not heated.
The reflectance of the BM film (laminated film of oxide thin film or nitride thin film and metal reflective layer) formed on the glass substrate was measured in the wavelength range of 400 to 700 nm. The reflectance spectrum was based on an aluminum vapor deposition film.
[0028]
【Example】
(Example 1)
<Production of In-based two-layer film>
A predetermined amount of sputtering gas and oxygen gas (O ₂ gas) is introduced, and an indium alloy target is sputtered by a reactive sputtering method in a sputtering atmosphere at a pressure of 0.67 Pa. An indium oxide thin film was formed.
[0029]
Next, the amount of oxygen gas introduced was reduced to 2 × 10 ⁻³ Pa, and the same indium alloy target was sputtered in a state where oxygen gas was present in the sputtering atmosphere.
[0030]
When an indium alloy target is sputtered only with argon gas, a metal thin film cannot be obtained and a powdery substance is deposited. As described above, a trace amount of 1 × 10 ⁻² Pa or less is present in the sputtering atmosphere. When oxygen gas is introduced, a metal reflection layer made of an indium thin film can be formed. Sputtering was terminated when a 1000 mm indium thin film was formed on the indium oxide thin film, and a BM film having a two-layer structure was obtained.
[0031]
As a result of forming the indium oxide thin film by varying the amount of oxygen gas introduced, when oxygen gas of 3 × 10 ⁻² Pa is introduced into the sputtering atmosphere, the average reflectance is the lowest at a wavelength of 400 to 700 nm, and the reflectance value A low reflection BM film having a small wavelength dependence was obtained. The measurement result of the reflectance of the BM film is shown in the graph of FIG.
[0032]
【Example】
(Example 2)
<Preparation of In-based three-layer film>
Using an indium target (In-5 wt% Sn) having the same component as in Example 1, a predetermined amount of oxygen gas was introduced into the sputtering atmosphere, and a first indium oxide thin film having a thickness of 350 mm was formed by reactive sputtering. Next, the amount of oxygen gas introduced was changed to form a second indium oxide thin film having a thickness of 350 mm to form a light-transmitting layer having a two-layer structure.
[0033]
Finally, sputtering was performed with a small amount (2 × 10 ⁻³ Pa) of oxygen gas introduced into the sputtering atmosphere, and an indium thin film was formed on the surface of the second indium oxide thin film.
[0034]
When an indium thin film having a thickness of 1000 mm was obtained, sputtering was terminated, and the indium thin film was used as a metal reflective layer to obtain a BM film composed of a laminated film having a three-layer structure.
[0035]
As a result of forming the first and second indium oxide thin films by varying the amount of oxygen gas introduced into various values and measuring the reflectance of the BM films, the first indium oxide thin film was 3.5 × 10 ^-2 Pa when forming, when introduced to 2.5 × 10 ^-2 Pa for oxygen gas when forming the indium oxide thin film of the second layer, the average reflectance in the wavelength 400~700nm is A BM film having the lowest wavelength dependency of the reflectance value was obtained. The reflectance characteristics of the BM film are shown in the graph of FIG.
[0036]
When the graph of FIG. 2 is compared with the graph of FIG. 1, the wavelength dependency of the reflectance characteristics of the BM film having the three-layer structure is further reduced as compared with the BM film having the two-layer structure.
[0037]
【Example】
Example 3
<Preparation of Zn-based two-layer film>
Next, using a target made of metallic zinc, a predetermined amount of oxygen gas was introduced into the sputtering atmosphere, and a zinc oxide thin film having a thickness of 500 mm was formed by a reactive sputtering method to obtain a light-transmitting layer.
[0038]
Next, the introduction of oxygen gas is stopped, the same target is sputtered in a sputtering atmosphere containing only argon gas, and a zinc metal reflective layer having a thickness of 1000 mm is continuously formed to form a metal reflective layer. A membrane was obtained.
[0039]
When a BM film was formed by varying the amount of oxygen gas introduced when forming the zinc oxide thin film and the reflectance was measured, a wavelength of 400 to 700 nm was obtained when 2.5 × 10 ⁻² Pa of oxygen gas was introduced. A BM film having the lowest average reflectance and a small wavelength dependence of the reflectance value was obtained. The reflectance characteristics of the BM film are shown in the graph of FIG.
[0040]
As can be seen from the graph of FIG. 3, the reflectance characteristics of the BM film are almost the same as the performance of the BM film having the indium-based two-layer structure (FIG. 1).
[0041]
【Example】
Example 4
<Preparation of Zn-based three-layer film>
As in Example 3, a target made of zinc metal was used, oxygen gas was introduced into the sputtering atmosphere, and a first zinc oxide thin film having a thickness of 350 mm was formed by reactive sputtering, The target is sputtered by changing the amount of oxygen gas added to form a second zinc oxide thin film having a thickness of 350 mm on the surface of the first zinc oxide thin film, and the first and second zinc oxide thin films. A light-transmitting layer was formed.
[0042]
Finally, the same target is sputtered in a sputtering atmosphere of only argon gas without introducing oxygen gas, and a metal zinc thin film having a thickness of 1000 mm is formed on the surface of the second zinc oxide thin film to form a metal reflective layer. Thus, a BM film composed of a laminated film having a three-layer structure was obtained.
[0043]
As a result of changing the oxygen gas introduction amount to various values and forming the first and second zinc oxide thin films, the reflectance characteristics of the obtained BM film are 3 × 10 ⁻² in the first layer. When oxygen gas of 2 × 10 ⁻² Pa was introduced into Pa and the second layer, the average reflectance at 400 to 700 nm was the lowest, and the wavelength dependence of the reflectance value was small.
The reflectance characteristics of the BM film are shown in the graph of FIG. The reflectance characteristics are equivalent to those of the BM film having the indium-based three-layer structure shown in the graph of FIG.
[0044]
【Example】
In Examples 1 to 4 above, an indium target (In-5 wt% Sn) or a metallic zinc target was used as the target. However, the target is an alloy target containing either indium or zinc as a main component (for example, In -Zn-based, Zn-Al-based, etc.) can be used.
Alternatively, an indium oxide (In-Sn-O-based) target or a zinc oxide (In-Zn-O-based, Zn-Al-O-based) target may be used.
[0045]
In Examples 1 to 4, argon gas is used as the sputtering gas, but other inert gases (Ne, Kr, Xe) and N ₂ gas may be used. Further, N ₂ gas may be added to the inert gas.
[0046]
In the first to fourth embodiments, oxygen gas is added to the sputtering gas when forming the oxide thin film, but carbon dioxide gas (CO ₂ gas) may be used instead of oxygen gas.
[0047]
When an oxide target is used as the target, a reducing gas such as hydrogen gas (H ₂ gas) or methane gas (CH ₄ gas) is used instead of the oxidizing gas, and the refractive index of the resulting oxide thin film is adjusted. It is also possible to do.
[0048]
In Examples 1 to 4, although the oxide thin film is used as the optical interference film, the light transmissive layer may be formed using a nitride thin film or a nitrided oxide thin film instead of the oxide thin film.
[0049]
In Examples 1 to 4 described above, a BM film having a two-layer structure or a three-layer structure is formed. However, the wavelength dependency of the reflectance value can be further reduced by forming the BM film with a laminated film of four or more layers.
[0050]
【The invention's effect】
By using a laminated film of a metal reflective layer mainly composed of indium or zinc and an oxide thin film or a nitride thin film instead of a BM film composed of a chromium-based laminated film, low pollution and low particle generation A reflective black BM film can be obtained.
In addition, the refraction of a light-transmitting thin film can be achieved by appropriately combining an oxidizing gas (O ₂ , CO ₂ ), a nitriding gas (N ₂ ), and a reducing gas (H ₂ , CxHy) according to the target used. By adjusting the rate, a BM film having a lower reflection than that of a conventional BM film made of a Cr-based laminated film can be obtained.
[Brief description of the drawings]
FIG. 1 is a graph showing the reflectance characteristics of an indium-based two-layer BM film. FIG. 2 is a graph showing the reflectance characteristics of an indium-based three-layer BM film. FIG. 4 is a graph showing the reflectance characteristics of a BM film having a zinc-based three-layer structure. FIGS. 5A and 5B are diagrams for explaining the light interference effect of the BM film. FIG. 6 is a diagram for explaining a color filter.
51, 71 ... BM film 54, 74 ... Translucent layer 55, 75 ... Metal reflective layer

Claims (3)

A translucent layer formed on a glass substrate;
A BM film having a metal reflective layer formed on the translucent layer,
The main component of the metal reflective layer, Ri either one der indium or zinc,
The light-transmitting layer has a nitride thin film containing either one of indium nitride or zinc nitride as a main component. A translucent layer formed on a glass substrate;
A BM film having a metal reflective layer formed on the translucent layer,
The main component of the metal reflective layer, Ri either one der indium or zinc,
The light-transmitting layer has an oxide thin film containing either indium oxide or zinc oxide as a main component . A BM film manufacturing method for manufacturing the BM film according to any one of claims 1 and 2 ,
A method for producing a BM film, comprising forming a metal indium thin film by sputtering a target mainly composed of indium in a sputtering atmosphere containing a sputtering gas and an oxygen gas having a pressure of 1 × 10 ⁻² Pa or less .

Images