Method for manufacturing optical thin films
The method of forming wash-removable films on substrates with aluminum compounds addresses the high costs and complexity of integrating optical thin films, achieving cost-effective and simplified production of anti-reflective and light-shielding films.
Patent Information
- Authority / Receiving Office
- JP · JP
- Patent Type
- Patents
- Current Assignee / Owner
- TOKAI OPTICAL CO LTD
- Filing Date
- 2021-11-17
- Publication Date
- 2026-05-13
Smart Images
Figure 0007857668000008 
Figure 0007857668000009 
Figure 0007857668000010
Abstract
Description
Technical Field
[0001] The present invention relates to a manufacturing method for forming on the surface of a substrate or the like. Optical thin film
Background Art
[0002] A camera module incorporated in a mobile terminal such as a smartphone or an electronic device such as a digital camera includes an imaging element that captures an object and a lens unit that forms an image of the object on the imaging element. above In particular, a small lens unit may include a light-shielding member for forming an annular light-shielding portion. The light-shielding member allows light to enter inside the light-shielding portion (transmission portion) and cuts a part or all of the light in the surrounding light-shielding portion, thereby restricting the incident range of incident light into the lens unit, suppressing the generation of stray light in the lens unit, preventing the occurrence of halation, lens flare, ghost, etc., and contributing to the improvement of image quality. Patent Document 1 (Japanese Unexamined Patent Application Publication No. 2020-140130) discloses a metal thin plate having a through-hole portion formed in the center as such a light-shielding member. This metal thin plate is manufactured by forming a resist pattern on a metal substrate and performing etching using this as a mask.
Prior Art Documents
Patent Documents
[0003]
Patent Document 1
Summary of the Invention
Problems to be Solved by the Invention
[0004] The light-shielding member described in Patent Document 1 is made of a thin metal sheet, and therefore the transparent portion needs to be a through-hole. Forming the through-hole requires a resist pattern process and an etching process, which increases manufacturing costs. Furthermore, in the transparent portion of the light-shielding member described in Patent Document 1, optical thin films cannot be placed as is. In order for optical thin films to be placed in the transparent portion, a separate member with the optical thin film formed on a different substrate from the light-shielding portion must be bonded to the through-hole portion of the light-shielding member described in Patent Document 1. In this case, the structure becomes complex, and manufacturing costs increase.
[0005] Therefore, the main objective of the present invention is to provide a method for manufacturing an optical thin film in which a first thin film portion and a second thin film portion are separated, and which can be manufactured at low cost. [Means for solving the problem]
[0006] The invention described in claim 1 is a method for producing an optical thin film having a first thin film portion and a second thin film portion having a different film structure from the first thin film portion, either directly or via an interlayer on the film-forming surface of a substrate, comprising the steps of: forming the first thin film portion on the first film-forming portion on the film-forming surface; forming a wash-removable film on the first thin film portion, which is at least one of aluminum and an aluminum compound having at least one of a fuzzy structure, a pyramidal group structure, and a pincushion structure; forming the second thin film portion on the second film-forming portion on the film-forming surface which is different from the first film-forming portion, and on the first film-forming portion on which the first thin film portion and the wash-removable film are formed; and removing the wash-removable film and the second thin film portion thereon by washing. The invention described in claim 2 is characterized in that, in the above invention, the second thin film portion is ring-shaped or frame-shaped. The invention described in claim 3 is characterized in that, in the above invention, the cleaning removal film is formed by immersing a cleaning removal base film, which is formed by a physical vapor deposition method using at least one of aluminum and an aluminum compound as a material, in hot water. The invention described in claim 4 is characterized in that, in the above invention, the cleaning removal film and the second thin film portion thereon are cleaned by at least one of running water and ultrasonic waves. The invention described in claim 5 is characterized in that, in the above invention, the second thin film portion is a light-shielding film that cuts out visible light. The invention described in claim 6 is characterized in that, in the above invention, the first thin film portion is an anti-reflective film that suppresses the reflection of visible light. The invention described in claim 7 is characterized in that, in the step of forming the first thin film portion, the first thin film portion is formed only on the first film-forming portion using a mask. The invention described in claim 8 is characterized in that, in the step of forming the first thin film portion, after forming the first thin film portion on the entire or partial film surface or the interlayer film, which includes a part of the first film-forming portion, the first thin film portion on the film-forming surface or the interlayer film other than the first film-forming portion is removed by laser. [Effects of the Invention]
[0008] The main effect of the present invention is to provide a method for manufacturing optical thin films that can produce optical thin films in which a first thin film portion and a second thin film portion are separated at low cost. [Brief explanation of the drawing]
[0009] [Figure 1] (A) a rear view and (B) a side view of a light-shielding AR lens member, which is formed by forming an optical thin film according to the first embodiment of the present invention on a substrate. [Figure 2] (A) a rear view and (B) a side view of an infrared cut member comprising an optical thin film formed on a substrate according to a second embodiment of the present invention. [Figure 3] (A) to (K) are schematic diagrams showing the manufacturing method of Example 1, which corresponds to the first embodiment of the present invention, mainly from the side view of the light-shielding AR lens member. [Figure 4](A) to (H) are schematic views mainly showing the manufacturing method of Example 1 from the back side of the light-shielding AR lens member. [Figure 5] It is a micrograph showing a structural example of the film removed during cleaning according to the present invention. [Figure 6] It is a graph related to the optical constants of SiO2. [Figure 7] It is a graph related to the optical constants of TiO2. [Figure 8] It is a graph related to the optical constants of Nb2O5. [Figure 9] It is a graph related to the optical constants of Nb + Si (the sputtering source input powers of Nb and Si in sputtering are 6 kW and 8.5 kW in order). [Figure 10] It is a graph of the reflectance distribution in the first thin film portion (AR film) of Example 1. [Figure 11] It is a graph of the reflectance distribution in the second thin film portion (light-shielding film) of Example 1. [Figure 12] It is a graph of the transmittance distribution in the second thin film portion (light-shielding film) of Example 1. [Figure 13] (A) and (B) are schematic views related to the manufacture of a ring-shaped light-shielding film in a comparative example not belonging to the present invention, and (C) is a rear view of the light-shielding AR lens member LZ in the comparative example. [Figure 14] It is a graph of the transmittance distribution in the first thin film portion (infrared cut film) of Example 2. [Figure 20] It is an enlarged view of the inner peripheral portion at the lower part of the ring in FIG. 19. [Figure 21] It is a graph of the reflectance distribution in each of the first thin film portion (AR film) and the second thin film portion (light shielding film) in the sample of FIG. 17.
Embodiments for Carrying out the Invention
[0010] Hereinafter, examples of embodiments according to the present invention will be described as appropriate using the drawings. Note that the present invention is not limited to the following examples.
[0011] [First Embodiment] As shown in FIG. 1, the optical thin film 1 according to the first embodiment of the present invention is formed on the film-forming surface F of a disk-shaped base material 2. As the material of the base material 2, plastic is used, preferably a thermosetting resin, for example, a polyurethane resin, a thiourethane resin, an episulfide resin, a polycarbonate resin, a polyester resin, an acrylic resin, a polyethersulfone resin, a poly-4-methylpentene-1 resin, a diethylene glycol bisallyl carbonate resin, or a combination thereof is used. Note that the material of the base material 2 may be other than plastic such as glass. The base material 2 with the optical thin film 1 is used as a light shielding AR lens member L in the lens unit of the camera module. Note that the base material 2 with the optical thin film 1 may be used other than in the lens unit.
[0012] The base material 2 is a base material on which the optical thin film 1 is formed, and particularly in the case of a plate shape, it is a substrate. The base material 2 has translucency, and the transmittance of visible light, which is light having a wavelength in the visible range of the base material 2 (here, 400 nm (nanometers) or more and 750 nm or less), is almost 100%. The base material 2 has a flat base portion 2B and a lens portion 2L that bulges from the base portion 2B to form a convex lens at the center on the film-forming surface F (back surface) side of the base portion 2B. The base portion 2B has a disk shape with a diameter of about 8 mm (millimeters). The outer shape of lens section 2L is circular, with a diameter of approximately 4 mm. The surface of lens section 2L is mirror-polished. However, the mirror polishing may be omitted. The substrate 2 has a textured, ring-shaped rough surface 2R formed around the lens portion 2L, with fine irregularities (for example, convex or concave bodies with a height of several micrometers). The rough surface 2R scatters passing light. Due to this scattering, the rough surface 2R appears cloudy to the naked eye. Furthermore, a flat peripheral portion 2S, which is ring-shaped and flat when viewed from the back, is formed radially outward from the rough surface 2R. The width of the rough surface 2R is approximately 1 mm. Furthermore, the rough surface portion 2R may be formed by molding with a mold that provides a shape corresponding to fine irregularities on its inner surface, or it may be formed by coating and fixing particles. The rough surface portion 2R does not have to be textured, and may be omitted. Alternatively, the peripheral flat portion 2S may be omitted, and the base material 2 The roughened surface portion 2R may extend to the periphery of the film-forming surface F. The lens portion 2L may be a concave lens rather than a bulging convex lens, and multiple lenses may be provided. At least one of the following may be changed from the above: the size of the base material 2, the size of the part of the base material 2, and its position relative to the whole.
[0013] The film deposition surface F and lens portion 2L on the substrate 2, which have the optical thin film 1 attached, are positioned to be inside the lens unit. In addition, the surface of the base portion 2B that faces the lens portion 2L (the side opposite to the film deposition surface F) is flat and is positioned to be the outer surface of the lens unit. Furthermore, the light-shielding AR lens member L may be arranged in other forms within the lens unit. Also, one or more interlayers may be placed between the substrate 2 and the optical thin film 1. The optical thin film 1 (film deposition surface F) may be placed on the surface opposite to the lens portion 2L, either in place of the surface on the lens portion 2L side or together with the surface on the lens portion 2L side. The surface of the base portion 2B opposite to the film deposition surface F may be curved.
[0014] The optical thin film 1 has a first thin film portion 10 and a second thin film portion 12. The first thin film portion 10 is located on the surface (first film deposition portion) of the lens portion 2L. The first thin film portion 10 is an optical multilayer film having an anti-reflection (AR) function. No resist or other materials (materials other than those constituting the first thin film portion 10 and the second thin film portion 12) remain in the first thin film portion 10. Note that the first thin film portion 10 is not limited to an AR film. The second thin film portion 12 is ring-shaped when viewed from the back and is located on the surface of the rough surface portion 2R and the surface of the peripheral flat portion 2S (second film-forming portion). The second thin film portion 12 is a light-shielding film having a light-cutting function that cuts at least visible light. No resist or the like remains on the second thin film portion 12. Note that the second thin film portion 12 is not limited to a light-shielding film. The light-shielding film may be a single layer or a multilayer film having multiple layers. Light cutting includes complete cutting, where the transmittance is approximately 0% across the entire visible range, incomplete cutting, where the transmittance is approximately 10% or less within the visible range, and partial cutting, where the transmittance is reduced before and after transmission. The second thin film portion 12 has a second A thin film portion 12A on the rough surface portion 2R and a second B thin film portion 12B on the peripheral flat portion 2S. The film structure is the same in the second A thin film portion 12A and the second B thin film portion 12B; the difference between them is whether they rest on the rough surface portion 2R or the peripheral flat portion 2S. The arrangement of the first thin film portion 10 and the second thin film portion 12 is not limited to the arrangement in which the ring-shaped second thin film portion 12 is in contact with the outside of the first thin film portion 10, which is disc-shaped when viewed from the back. For example, the first thin film portion 10 and the second thin film portion 12 may overlap or be separated on the rough surface portion 2R. Also, the second thin film portion 12 does not have to be arranged on part or all of the peripheral flat portion 2S.
[0015] [Second form] As illustrated in Figure 2, the optical thin film 51 according to the second embodiment of the present invention is formed on the film surface of a rectangular plate-shaped plastic substrate 52. F2 It is formed on the (back) surface. The second embodiment may have modifications similar to those of the first embodiment as appropriate. For example, the base material 52 may be made of glass or the like. The substrate 52 with the optical thin film 51 is used as an infrared cut-off member R. However, the substrate 52 with the optical thin film 51 may be used for purposes other than the infrared cut-off member R. The substrate 52 has a central portion 52C and a rectangular frame-shaped peripheral portion 52R. The film-forming surface F side of the central portion 52C is mirror-finished. Also, the film-forming surface of the peripheral portion 52R F2 The sides are roughened, similar to the roughened surface section 2R of the first form.
[0016] The optical thin film 51 has a first thin film portion 60 and a second thin film portion 62. The first thin film portion 60 is rectangular in shape when viewed from the back and is located on the back side (first film deposition portion) of the central portion 52C. The first thin film portion 60 is an optical multilayer film having an infrared-cutting function. No resist or other materials remain on the first thin film portion 60, except for substances such as water that may adhere in the air. Note that the first thin film portion 60 is not limited to an infrared-cutting film. The second thin film portion 62 has a rectangular frame shape when viewed from the back and is located on the back side (second film deposition portion) of the peripheral edge portion 52R. The second thin film portion 62 is the same as the second thin film portion 12 of the first embodiment, except for its shape. The radially inner boundary of the second thin film portion 62 is in contact with the boundary of the first thin film portion 60. However, the arrangement of the first thin film portion 60 and the second thin film portion 62 is not limited to the arrangement in which the frame-shaped second thin film portion 62 is in contact with the outside of the first thin film portion 60, which is rectangular in rear view.
[0017] [Manufacturing method etc.] The first and second forms of optical thin films 1 and 51 are manufactured using a cleaning-removed film W (see Figures 3 and 4) which is ultimately removed by cleaning. The cleaning-removed film W is a manufacturing intermediate that is formed during manufacturing and does not remain after manufacturing. The film W removed during cleaning is aluminum, an aluminum alloy, or an aluminum compound. Preferably, the aluminum compound is a compound with aluminum as the main component. The main component may be a component that constitutes more than half by weight or more than half by volume compared to the other components. The film removed during cleaning, W, is, for example, aluminum (Al), aluminum oxide (Al2O3), aluminum nitride (AlN), or aluminum oxynitride (AlON). In the case of AlON, the ratio of oxygen atoms to nitrogen atoms can be anything; AlON may have a large proportion of oxygen atoms relative to nitrogen atoms, giving it properties similar to Al2O3, or it may have a small proportion of oxygen atoms relative to nitrogen atoms, giving it properties similar to AlN, or it may contain roughly equal amounts of oxygen and nitrogen atoms. The film W removed during cleaning has at least one of the following structures (hereinafter referred to as "fluffy structure, etc.") as shown in Figure 5 (AlN): a fine fuzzy structure, a pyramidal group structure, and a pincushion-like structure. Such a fuzzy structure, etc. imparts to the film removed during cleaning the property that it can be used to form a light-shielding film or the like on top of it, and that it can be removed by peeling or other means using cleaning with at least one of running water and ultrasound. The cleaning-removable film W having a fuzzy structure, etc., is formed from a cleaning-removable base film WB that does not have a fuzzy structure, etc., but is suitable for direct deposition by physical vapor deposition (PVD), vacuum deposition, sputtering, etc. The cleaning-removable film W is formed, for example, by subjecting the cleaning-removable base film WB to at least one of ultrasonic treatment (applying ultrasonic waves) and hot water immersion treatment (immersing in hot water). Furthermore, the film W removed during cleaning may not be completely removed by cleaning, and a small amount may remain after the formation of the optical thin film 1. Even in this case, the remaining substance is aluminum, aluminum alloy, or an aluminum compound, and does not substantially affect the optical properties of the optical thin film 1. The present invention includes the case in which a portion of the film W removed during cleaning remains.
[0018] The first embodiment of the optical thin film 1 is manufactured, for example, by forming a first thin film portion 10 on a lens portion 2L, forming a cleaning removal film W on the first thin film portion 10, forming a light-shielding film of the second thin film portion 12 on the rough surface portion 2R, the peripheral flat portion 2S, and the cleaning removal film W, and then, through subsequent cleaning, the cleaning removal film W is removed together with the light-shielding film formed on it, while the light-shielding film on the rough surface portion 2R and the peripheral flat portion 2S remains even after cleaning, forming a back-view ring-shaped second thin film portion 12.
[0019] The second form of the optical thin film 51 is manufactured by, for example, forming a first thin film portion 60 on the central part of the film deposition surface F2, forming a cleaning-removable film W on the first thin film portion 60, forming a light-shielding film of the second thin film portion 62 over the entire surface of the film deposition surface F2 with the first thin film portion 60 and the cleaning-removable film W, and then, by subsequent cleaning, the cleaning-removable film W is removed together with the light-shielding film formed on it, and the film deposition surface F2 The light-shielding film on the periphery remains even after cleaning, forming a second thin film portion 62 in the shape of a rectangular frame when viewed from the back.
[0020] [Examples of changes, etc.] Further modifications based on the above forms or examples of changes are described below. In the first embodiment, a light-shielding film may be formed in the central part of the film-forming surface F, and an AR film may be formed in the peripheral part. In the second form, the film deposition surface F2 A light-shielding film may be formed in the central part, and an infrared-cutting film may be formed on the periphery. Not limited to the above-described forms and modifications, the manufacturing of a film using the cleaning-removed film W according to the present invention is applicable to the formation of different types of film portions on multiple parts of various film-forming surfaces. For example, AR film portions with different layer structures may be formed in the central and peripheral parts of film-forming surfaces F and F2. Alternatively, mirror film portions with different layer structures may be formed in the central and peripheral parts of film-forming surfaces F and F2. An AR film portion may be formed in the central part of film-forming surfaces F and F2 and a mirror film portion may be formed in the peripheral part, or the arrangement may be reversed. An AR film portion may be formed in the central part of film-forming surfaces F and F2 and an infrared-cutting film portion may be formed in the peripheral part, or the arrangement may be reversed. An infrared-cutting film portion may be formed in the central part of film-forming surfaces F and F2 and a mirror film portion may be formed in the peripheral part, or the arrangement may be reversed. The arrangement of each film portion is not limited to the central part and the peripheral part. The present invention may also be applied to optical thin films having three or more film portions.
[0021] [Third form] The optical thin film according to the third embodiment of the present invention is the same as that of the first embodiment, except for the manufacturing method. Components and parts that are the same as those of the first embodiment are appropriately denoted by the same reference numerals, and their descriptions are omitted.
[0022] The third form of the optical thin film 1 is manufactured by, for example, forming a first thin film portion 10 on the rough surface portion 2R, the peripheral flat portion 2S, and the lens portion 2L (on the film deposition surface F), forming a cleaning removal film W on the first thin film portion 10, and removing the first thin film portion 10 and the cleaning removal film W on the rough surface portion 2R and the peripheral flat portion 2S by laser irradiation or the like. The subsequent manufacturing method is the same as that of the first embodiment. Specifically, in the subsequent manufacturing process, a light-shielding film of the second thin film portion 12 is formed on the rough surface portion 2R, the peripheral flat portion 2S, and the film removed during cleaning W. During subsequent cleaning, the film removed during cleaning W is removed along with the light-shielding film formed on it, while the light-shielding film on the rough surface portion 2R and the peripheral flat portion 2S remains even after cleaning, forming a ring-shaped second thin film portion 12 when viewed from the back. Furthermore, the third form may have modifications similar to those of the first and second forms, as appropriate. [Examples]
[0023] Next, preferred embodiments of the present invention and comparative examples not belonging to the present invention will be described. Furthermore, the present invention is not limited to the following embodiments. Depending on how the present invention is interpreted, the following embodiments may substantially become comparative examples, and vice versa.
[0024] [Example 1] <<Configuration of optical thin films, etc.>> Example 1 corresponds to the first embodiment (light-shielding AR lens member L) described above. In Example 1, the first thin film portion 10 (AR film) of the optical thin film 1 is a five-layer optical multilayer film, as shown in Table 1, and consists of alternating layers of low refractive index layers formed from a low refractive index material and high refractive index layers formed from a high refractive index material. More specifically, the first thin film portion 10 consists of low refractive index layers (SiO2 layers) made of SiO2 as the 1st, 3rd, and 5th layers (odd-numbered layers) counting from the substrate 2 side, and high refractive index layers (TiO2 layers) made of TiO2 as the 2nd and 4th layers (even-numbered layers). Note that Table 1 also lists the base film WB (Al2O3), which is removed during cleaning and is not a component of the first thin film portion 10, as the 6th layer. Furthermore, the second thin film portion 12 (light-shielding film) of the optical thin film 1 is a total of nine optical multilayer films, as shown in Table 2 below, and consists of alternating layers of low refractive index layers and high refractive index layers. More specifically, the first thin film portion 10 consists of SiO2 layers for the 1st, 3rd, 5th, 7th, and 9th layers (odd-numbered layers) counted from the substrate 2 side, a high refractive index layer (Nb2O5 layer) made of niobium oxide (Nb2O5) for the 2nd layer (part of the even-numbered layers), and a high refractive index layer (Nb+Si layer) made of niobium silicon alloy (Nb+Si) for the 4th, 6th, and 8th layers (the other part of the even-numbered layers). The Nb+Si layer is a light-absorbing layer that absorbs visible light, and due to its properties, it exhibits similar behavior to the high refractive index layer. Furthermore, the low refractive index material may be calcium fluoride (CaF2), magnesium fluoride (MgF2), or a mixture of two or more of these including SiO2. The high refractive index material may also be zirconium oxide (ZrO2), tantalum oxide (Ta2O5), niobium oxide (Nb2O5), hafnium oxide (HfO2), selenium oxide (CeO2), aluminum oxide (Al2O3), yttrium oxide (YO2), or a mixture of two or more of these including TiO2. In the optical multilayer film related to the first thin film section 10, since one high refractive index material and one low refractive index material are used, film design is easy and the film deposition cost is low.
[0025] [Table 1] [Table 2]
[0026] Manufacturing of optical thin films, etc. Next, a method for manufacturing Example 1 will be described. Furthermore, the method for manufacturing the optical thin film 1 according to the present invention is not limited to the following forms, including the manufacturing apparatus.
[0027] In the manufacturing of Example 1, the first thin film portion 10, the base film WB removed during cleaning, and the second thin film portion 12 of the optical thin film 1 are all formed by DC sputtering in a DC sputtering deposition apparatus. In the manufacturing of Example 1, Al2O3 is used as the base film WB removed during cleaning. Table 3 shows the process conditions for various sputtering processes. Furthermore, Figures 6 to 9 show the optical constants (refractive index distribution and extinction coefficient in the visible and adjacent regions) of various materials. Furthermore, at least one of the first thin film portion 10, the base film WB removed during cleaning, and the second thin film portion 12 may be formed by other methods such as vapor deposition. Also, an RF sputtering deposition apparatus may be used instead of a DC sputtering deposition apparatus. Moreover, the number of layers of each film and the thickness of each layer can be changed as appropriate.
[0028] [Table 3]
[0029] As shown in Figure 4(A), the substrate 2 before film deposition is placed in the vacuum deposition chamber of the sputter deposition apparatus in a horizontal position with the film deposition surface F (back surface) facing upwards. A mask M is then set above the film deposition surface F on the substrate 2 before film deposition, as shown in Figures 3(A) and 4(B). The mask M has a plate-shaped base MB and a through-hole MH in the center of the base MB, which is shaped to correspond to the shape of the first thin film portion 10. The mask M is supported by a film deposition holder via a support. Furthermore, the various arrangements and number of components used in the manufacturing method of the optical thin film 1 are not limited to those described above. For example, the substrate 2 and the mask M may be in a vertical position. Multiple substrates 2 may be arranged vertically and horizontally, and the mask M may have multiple through holes corresponding to that arrangement.
[0030] Next, as shown in Figures 3(B) and 4(C), the first thin film portion 10 is formed, followed by the base film WB removed during cleaning. Note that the first thin film portion 10 and the base film WB removed during cleaning may be manufactured using separate equipment. Specifically, first, various targets are set and the deposition chamber is evacuated. Then, as shown in Table 3 as "pretreatment," O2 gas is supplied from a radical source to the deposition chamber at a flow rate of 500 ccm for 30 seconds, after being converted into radical oxygen by the application of a high-frequency voltage. This cleans the substrate 2 and mask M. More specifically, even if organic matter is attached to the substrate 2 and mask M, such radical oxygen irradiation decomposes and removes it due to the ultraviolet light generated by the radical oxygen and plasma. This cleaning improves the adhesion of the film that is subsequently formed. Then, the first layer (SiO2 layer) of the first thin film section 10 is sputtered under the process conditions described above (Table 3). Here, the Si sputtering source is activated along with the introduction of argon gas (Ar gas), and oxygen gas (O2 gas) is introduced into the deposition chamber as a radical source. The mask M is placed between the substrate 2 and the sputtering source. Next, the second layer (TiO2 layer) of the first thin film section 10 is sputtered in the same manner. Here, the Ti sputtering source is activated, and O2 gas is introduced into the deposition chamber as a radical source. Subsequently, the 3rd to 5th layers are sputtered in the same manner, and the first thin film section 10 is deposited. Note that Ar gas may be introduced as a radical source instead of, or together with, the sputtering source. The Ar gas may be a rare gas other than Ar. Such changes regarding Ar gas may be made as appropriate in other film deposition processes as well. Next, the base film WB (Al2O3) removed during cleaning is sputtered onto the first thin film portion 10 under the process conditions described above (Table 3). Here, the Al sputtering source operates with the introduction of Ar gas, and the radical source operates with oxygen radicals. The first thin film portion 10 and the base film WB removed during cleaning are formed on the lens portion 2L of the substrate 2 through the through-holes MH of the mask M.
[0031] Next, as shown in Figures 3(C) and 4(D), the substrate 2 with the first thin film portion 10 and the base film WB removed during cleaning is temporarily removed from the sputtering deposition apparatus. Then, as shown in Figure 3(D), the substrate 2 with the first thin film portion 10 and the base film WB to be removed during cleaning is immersed in hot water HW in the water tank T. As a result, as shown in Figures 3(E) and 4(E), the base film WB to be removed during cleaning becomes the film W to be removed during cleaning, which has a fuzzy structure, etc. That is, the uniformly distributed structure of Al2O3 in the base film WB to be removed during cleaning changes to exhibit a fuzzy structure, etc., accompanied by dissolution in the hot water HW. In other words, the base film WB to be removed during cleaning gradually changes into the film W to be removed during cleaning, as it dissolves partially as appropriate in the hot water HW and grows numerous fine fluff, pyramidal structures, cones, needle-like structures, etc., in the direction of film thickness. The change from the base film WB to the film W to be removed during cleaning can be considered etching, as the strength of the film decreases due to the presence of the fuzzy structure, etc. On the other hand, hot water HW does not cause any adverse effects on the first thin film portion 10, such as deformation or short-term weakening. Furthermore, the orientation (direction) of the substrate 2 during immersion is not limited to the vertical orientation shown in Figure 3. In addition to immersion in hot water, etching can also be performed by applying ultrasound in addition to immersion in hot water. The temperature of the hot water HW is 90°C, preferably 60°C to 100°C, more preferably 80°C to 100°C, and even more preferably 90°C to 100°C, from the viewpoint of obtaining a fuzzy structure and the like in the shortest possible time. To reach a temperature of 100°C or higher, it is necessary to subject the water to special treatments such as pressurization or to use something other than water, which is time-consuming. Furthermore, the immersion time in hot water HW is preferably 2 seconds to 10 minutes, more preferably 5 seconds to 5 minutes, and even more preferably 15 seconds to 3 minutes, from the viewpoint of obtaining a fuzzy structure, etc., in the shortest possible time. If the immersion time is too short, a fuzzy structure, etc., will not be sufficiently obtained, and if the immersion time is too long, the processing time will be longer and the efficiency will be reduced accordingly.
[0032] Subsequently, as shown in Figure 3(F), the substrate 2 with the first thin film portion 10 and the film removed during cleaning W attached is removed from the water tank T and returned to the sputtering deposition apparatus, and as shown in Figures 3(G) and 4(F), the light-shielding film of the second thin film portion 12 is deposited over the entire deposition surface F. Note that the first thin film portion 10 and the light-shielding film may be manufactured using separate apparatuses. Specifically, first, without mask M, the first layer (SiO2 layer) of the second thin film section 12 is sputtered in the same way as the SiO2 layer of the first thin film section 10. Next, the second layer (Nb2O5 layer) of the second thin film section 12 is sputtered under the process conditions described above (Table 3). Here, the Nb sputtering source operates along with the introduction of Ar gas, and O2 gas is introduced into the deposition chamber as a radical source. Subsequently, the third layer (SiO2 layer) of the second thin film section 12 is sputtered in the same way. Next, the fourth layer (Nb+Si layer) of the second thin film section 12 is sputtered in the same way. In the sputtering of the Nb+Si layer, the Nb sputtering source and the Si sputtering source operate simultaneously, and the radical source does not operate. Next, the 5th to 7th layers are sputtered in the same manner, and the light-shielding film relating to the second thin film portion 12 is formed on the rough surface portion 2R and the peripheral flat portion 2S of the substrate 2, as well as on the film removed during cleaning W.
[0033] After the entire surface of the light-shielding film has been formed, as shown in Figure 3(H), the substrate 2 with the light-shielding film, the film removed during washing W, and the first thin film portion 10 is placed back into the water tank T and immersed in hot water HW. As shown in Figures 3(I) and 4(G), the light-shielding film on the film W removed during cleaning becomes a weakened second thin film portion 12E having cracks and a weakened structure. The change from the second thin film portion 12 to the weakened second thin film portion 12E on the film W removed during cleaning can be considered etching, and since it is the second etching, it can be considered re-etching. In re-etching, the second thin film portion 12 and the first thin film portion 10 on the substrate 2 are not affected by weakening or other adverse effects, and there is no change in the adhesion of the first thin film portion 10 and the second thin film portion 12 to the film-forming surface F. Furthermore, during re-etching, the fluffy structure of the film W removed during cleaning is further refined, and a portion of the film W removed during cleaning is dissolved. Furthermore, the water tank T for removing the film W during cleaning and the water tank T for the second thin film portion 12 may be provided separately from each other. Also, in these water tanks T, T, at least one of the temperature of the hot water HW and the immersion time may be different from each other. Moreover, the re-etching may have appropriate modifications to the first etching. For example, in the re-etching, ultrasonic treatment may be performed instead of, or in conjunction with, the hot water immersion treatment. In addition, the weakened structure of the weakened second thin film portion 12E is not limited to cracks.
[0034] The substrate 2, with the first thin film portion 10, the second thin film portion 12, the weakened second thin film portion 12E, and the film removed during cleaning W, is removed from the water tank T and then washed with running water as shown in Figure 3(J) (see arrow A). Alternatively, cleaning may be performed by ultrasound instead of, or in conjunction with, running water. As a result, the weakened second thin film portion 12E and the film removed during cleaning W are separated from the first thin film portion 10, and a substrate 2 with an optical thin film 1, i.e., a light-shielding AR lens member L, is completed, in which the second thin film portion 12 is arranged around the first thin film portion 10 with a uniform film thickness, as shown in Figures 3(K) and 4(H). That is, the film removed during cleaning W and the second thin film portion 12 on it are removed by cleaning, the first thin film portion 10 appears on the surface of the lens portion 2L, and the state in which the second thin film portion 12 is arranged changes from a state in which it is arranged on the surface of the rough surface portion 2R and the surface of the peripheral flat portion 2S to a state in which it is arranged only on the surface of the rough surface portion 2R and the peripheral flat surface portion 2S. In such an optical thin film 1, the Al2O3 in the film W removed during cleaning has reduced adhesion to the first thin film portion 10 below it due to its fine, fuzzy structure, and is therefore completely removed by cleaning with at least one of running water and ultrasonic waves, leaving no residue. Furthermore, due to the weakened second thin film portion 12E having cracks and the film W removed during cleaning having a fuzzy structure, the light-shielding film is selectively removed only from the portion above the lens portion 2L. Since the adhesion of the first thin film portion 10 to the surface of the lens portion 2L and the adhesion of the second thin film portion 12 to the rough surface portion 2R and the peripheral flat portion 2S are both ensured, the first thin film portion 10 and the second thin film portion 12 in these respective portions do not peel off and are not removed from the substrate 2 by cleaning with at least one of running water and ultrasonic waves. Moreover, as described above, even if a small amount of the film W removed during cleaning remains, it does not have a significant impact on the optical thin film 1, etc. Furthermore, the film W removed during cleaning can be removed without using organic solvents, thus preventing the effects of organic solvents on the optical thin film 1, the substrate 2, and the interlayer. In particular, many plastic substrates 2 are susceptible to organic solvents, and dissolution and cracking occur due to the action of organic solvents. However, by removing the film W during cleaning without using organic solvents, such dissolution and cracking are prevented. Therefore, forming the optical thin film 1 using the film W removed during cleaning is particularly effective for plastic substrates 2. The water temperature of the flowing water can be anything, but from the viewpoint of ease of handling, it is preferable that it be around room temperature (tap water temperature). The flow rate of the water can be any amount that is sufficient to separate the entire weakened second thin film portion 12E and the film removed during cleaning W. The same applies to the output of the ultrasound. The cleaning time, which is the time spent treating with at least one of running water and ultrasound, can be any time required for the entire weakened second thin film portion 12E and the cleaning-removed film W to be separated. From the viewpoint of shortening the time while ensuring sufficient cleaning, it is preferably 30 seconds to 10 minutes, more preferably 1 minute to 5 minutes, and even more preferably 2 minutes to 3 minutes.
[0035] Characteristics of Example 1 Figure 10 is a graph of the reflectance distribution in the visible and adjacent regions on the surface (center point) of the lens portion 2L on which the first thin film portion 10 (AR film) of Example 1 is formed. This graph shows that low reflectivity to visible light is achieved in the lens portion 2L of Example 1. The surface of the lens portion 2L is mirror-finished and given a first thin film portion 10, and since the substrate 2 is light-transmitting, the lens portion 2L of Example 1 transmits most of the visible light.
[0036] Figure 11 is a graph of the reflectance distribution in the visible and adjacent regions for the surface of the rough surface 2R on which the second thin film portion 12 (light-shielding film) of Example 1 is formed, relating to the reflectance of reflected light incident from the air and reflected by the second thin film portion 12 (second A thin film portion 12A) (reflectance on the light-shielding film), and the reflectance of reflected light incident from the substrate 2 side and reflected by the surface of the rough surface 2R (interface reflectance). Reflectance is measured by the proportion of test light emitted from the reflectance meter that returns to the meter. Since the test light is scattered by the irregularities of the rough surface 2R, the reflectance on the light-shielding film and the reflectance at the interface in Example 1 are both sufficiently low, at 0.5% or less across the entire visible spectrum. Figure 12 is a graph of the transmittance distribution in the visible and adjacent regions on the rough surface 2R of Example 1, where the second thin film portion 12 (light-shielding film) is formed. In the roughened surface portion 2R of Example 1, extremely low transmittance is achieved in the visible and adjacent regions. With the roughened surface portion 2R having the second thin film portion 12, the light-shielding AR lens member L of Example 1 sufficiently suppresses the generation of stray light within the lens unit.
[0037] The uniformity of the film thickness in the second thin film portion 12 of Example 1 will be explained below with reference to a comparative example. Figures 13(A) and (B) are schematic diagrams relating to the manufacturing of the ring-shaped light-shielding film in the comparative example, and Figure 13(C) is a rear view of the light-shielding AR lens member LZ in the comparative example. In the comparative example, after forming the AR film 10Z in the center, as in Example 1, the base film WB that is removed during washing is not formed, and a light-shielding film 12Z is formed around the AR film 10Z using a bridged mask MZ. The bridge-equipped mask MZ comprises a base MZB, a circular through-hole MZH in the center thereof which is the same size as the light-shielding AR lens member LZ, a central mask MZC which is a disc the same size as the lens portion 2LZ and is concentric with the through-hole MZH, and a bridge MZR which extends inward from the outer portion of the through-hole MZH in the base MZB and reaches the central mask MZC to support the central mask MZC. The through-holes MZH in the bridged mask MZ, excluding the central mask MZC portion, form a ring-shaped light-shielding film 12Z. The central mask MZC prevents the formation of the light-shielding film on the AR film 10Z. However, during the formation of the light-shielding film 12Z, the multiple (four) bridges MZR supporting the central mask MZC prevent the film material from reaching the substrate 2Z. As a result, the light-shielding film 12Z of the comparative example has thinned areas 12ZT corresponding to the bridges MZR, and its film thickness becomes non-uniform. In some cases, there may be no film material for the light-shielding film 12Z at all in the thinned areas 12ZT (unformed areas). Such thinned areas 12ZT can occur even if the bridges MZR are reduced to their minimum size while still being able to support the central mask MZC. In contrast, the second thin film portion 12 of Example 1 is formed in a ring shape with extremely high uniformity of film thickness due to the film W removed during cleaning. Furthermore, while the comparative example requires two types of masks—a mask for the AR film 10Z and a bridged mask MZ—Example 1 requires only one mask M for the first thin film portion 10 and the base film WB removed during cleaning. Thus, Example 1 is easier to manufacture than the comparative example.
[0038] Examples of changes to the formation of the base film removed during cleaning, etc. Table 4 shows examples of manufacturing conditions, etc., related to changes in the formation of the base film WB removed during cleaning. Note that the top manufacturing conditions in Table 4 relate to Example 1. Also, "EB" in Table 4 refers to electron beam.
[0039] [Table 4]
[0040] In other words, as shown in the second manufacturing condition from the top in Table 4, the base film WB removed during cleaning may be an Al film formed by vapor deposition. Furthermore, as shown in the third manufacturing condition from the top in Table 4, the base film WB removed during cleaning may be an Al2O3 film formed by vapor deposition. Furthermore, as shown in the fourth manufacturing condition from the top in Table 4, the base film WB removed during cleaning may be an Al film formed by sputtering. Furthermore, as shown in the fifth manufacturing condition from the top in Table 4, the base film WB removed during cleaning may be an AlN film formed by sputtering. Note that forming an AlN film is difficult with conventional vapor deposition. In addition, as shown in the manufacturing conditions listed first from the bottom in Table 4, the base film WB removed during cleaning may be an AlON film formed by sputtering. Note that AlON film formation is difficult with conventional vapor deposition. Alternatively, the base film WB removed during cleaning may be a combination of these, including Al alone. These washable base films WB can be transformed into washable films W by immersing them in hot water to create a fine, fuzzy structure, as in the washable base film WB of Example 1.
[0041] [Example 2] <<Configuration of optical thin films, etc.>> Example 2 corresponds to the second embodiment (infrared-cutting member R) described above. In Example 2, the first thin film portion 60 (infrared cut film) of the optical thin film 51 is an optical multilayer film with a total of 45 layers, as shown in Table 5 below, and consists of alternating layers of low refractive index layers (SiO2 layers, odd-numbered layers) and high refractive index layers (TiO2 layers, even-numbered layers). Furthermore, the second thin film portion 62 (light-shielding film) of the optical thin film 51 is the same as the second thin film portion 12 of Example 1. Furthermore, Example 2 may have modifications similar to those in Example 1, including its manufacturing process.
[0042] [Table 5]
[0043] Manufacturing of optical thin films, etc. Next, a method for manufacturing Example 2 will be described. Furthermore, the method for manufacturing the optical thin film 51 according to the present invention is not limited to the following forms, including the manufacturing apparatus.
[0044] In the manufacturing of Example 2, the first thin film portion 60, the base film WB removed during cleaning, and the second thin film portion 62 of the optical thin film 51 are all formed by DC sputtering in the same manner as in Example 1, except for the number of layers of the first thin film portion 60 and the shape of the mask M. Alternatively, the first thin film portion 60 of the optical thin film 51 may be formed by vapor deposition. The process conditions in this case are shown in Table 6. If the first thin film portion 60 is formed by vapor deposition, and the base film WB removed during cleaning is also formed by vapor deposition (see the second and third manufacturing conditions in Table 4), then the first thin film portion 60 and the base film WB removed during cleaning can be formed using the same apparatus, thus ensuring ease of manufacturing.
[0045] [Table 6]
[0046] The DC sputtering process in Example 2 is carried out in the same manner as in Example 1 (see Figures 3 and 4). When the first thin film portion 60 and the base film WB removed during cleaning are formed by vapor deposition, Figures 3(A) and 3(B) show the vapor deposition process using a vapor deposition apparatus, and Figure 3(G) shows the sputtering process using a sputtering apparatus. Furthermore, various conditions such as immersion time in at least one of etching (Figures 3(D) to (E)) and re-etching (Figures 3(H) to (I)) may be adjusted according to the characteristics of the first thin film portion 60 (infrared cut film).
[0047] ≪Characteristics of Example 2≫ Figures 14 and 15 are graphs of the transmittance and reflectance distributions in the visible region, near-infrared region (here, 750 nm to 1200 nm) and adjacent regions at the central part 52C surface (center point) where the first thin film portion 60 (infrared cut film) of Example 2 is formed. This graph shows that in the central part 52C of Example 2, the near-infrared light cutoff is mainly achieved by reflection.
[0048] The properties such as transmittance on the peripheral portion 52R surface where the second thin film portion 62 (light-shielding film) of Example 2 is formed are the same as the properties such as transmittance on the rough surface portion 2R surface where the second thin film portion 12 of Example 1 is formed (see Figures 11 and 12). Therefore, in the peripheral portion 52R of Example 2, extremely low transmittance is achieved in the visible and adjacent regions. With the peripheral portion 52R with the second thin film portion 12, the infrared cut member R of Example 2 sufficiently suppresses the generation of stray light inside.
[0049] Summary etc. The method for producing Examples 1 and 2 is a method for producing an optical thin film 1,51 having first thin film portions 10,60 and second thin film portions 12,62 having a different film structure from the first thin film portions 10,60 on the film formation surfaces F,F2 of a substrate 2,52, and includes the steps of: forming the first thin film portions 10,60 on the first film formation portion on the film formation surfaces F,F2; forming a washable film W on the first thin film portions 10,60 which is at least one of aluminum and an aluminum compound having a fuzzy structure or the like; forming the second thin film portions 12,62 on the second film formation portion on the film formation surface F,F2 which is different from the first film formation portion, and on the first film formation portion on which the first thin film portions 10,60 and the washable film W are formed; and removing the washable film W and the second thin film portions 12,62 thereon by washing. Therefore, an optical thin film in which the first thin film portion and the second thin film portion are separated can be manufactured at a high quality and low cost without using a resist, a bridging mask MZ, or an organic solvent. Furthermore, the phrase "on top of" the film-forming surface, the first film-forming portion, and the second film-forming portion includes both states where the object is in contact with the film-forming surface, the first film-forming portion, and the second film-forming portion, and states where the object is not in contact with the film-forming surface, the first film-forming portion, and the second film-forming portion, but is separated by an interlayer, yet is located above them.
[0050] Furthermore, in the method for manufacturing Examples 1 and 2, the second thin film portions 12 and 62 are ring-shaped and frame-shaped, respectively. Therefore, ring-shaped or frame-shaped thin film portions, which were previously difficult to manufacture at low cost and with high quality, can now be manufactured at low cost and with high quality. Furthermore, in the method for producing Examples 1 and 2, the cleaning removal film W is formed by immersing a cleaning removal base film WB, which is formed by a physical vapor deposition method using at least one of aluminum and an aluminum compound as the material, in hot water. Therefore, a cleaning removal film W having a fuzzy structure necessary for forming the second thin film portions 12 and 62, which are separated from the first thin film portions 10 and 60, can be easily formed. Furthermore, in the method for producing Examples 1 and 2, the film W removed during cleaning and the second thin film portions 12 and 62 thereon are cleaned by at least one of running water and ultrasonic waves. Therefore, the cleaning process can be easily carried out.
[0051] Furthermore, in the method for manufacturing Examples 1 and 2, the second thin film portions 12 and 62 are light-shielding films that cut visible light. Therefore, ring-shaped or frame-shaped light-shielding films for purposes such as preventing stray light in lens units can be formed at low cost and with high quality. Furthermore, in the method for manufacturing Examples 1 and 2, the first thin film portions 10 and 60 are AR films that suppress the reflection of visible light. Therefore, the first thin film portions 10 and 60 are provided with the function of suppressing the reflection of visible light.
[0052] In addition, the optical thin films 1,51 of Examples 1 and 2 have a first thin film portion 10,60 and a second thin film portion 12,62 having a different film structure, with the second thin film portion 12,62 surrounding the first thin film portion 10,60, and no resist remaining on the first thin film portion 10,60. Therefore, in the optical thin films 1.51 of Examples 1 and 2, no resist remains as in the one described in Patent Document 1, and no thinned portion 12ZT is formed as in the comparative example above. Thus, an optical thin film 1.51 is provided in which the first thin film portion 10,60 and the second thin film portion 12,62 are simply separated in a high-quality state.
[0053] Furthermore, in the optical thin film 1.51 of Examples 1 and 2, the second thin film portions 12 and 62 are light-shielding films that cut visible light. Therefore, the optical thin film 1.51 having a ring-shaped or frame-shaped light-shielding film for stray light prevention in a lens unit is of high quality. Furthermore, in the optical thin film 1,51 of Examples 1 and 2, the first thin film portion 10,60 is an AR film that suppresses the reflection of visible light. Therefore, the reflection of visible light is suppressed in the first thin film portion 10,60 surrounded by the second thin film portion 12,62. In addition, in the process of forming the first thin film portions 10 and 60 in Examples 1 and 2 (Figures 3(A) to (B), Figures 4(A) to (D)), the mask M is used to form the first thin film portions 10 and 60 only on the first film deposition area (the surface of the lens portion 2L). Therefore, the first thin film portions 10 and 60 can be easily formed in a desired shape corresponding to the shape of the mask M.
[0054] [Example 3] <<Configuration of optical thin films, etc.>> Example 3 corresponds to the third embodiment (light-shielding AR lens member L) described above. In Example 3, the configuration of the first thin film portion 10 (AR film) and the second thin film portion 12 (light-shielding film) are the same as in Example 1 described above.
[0055] Manufacturing of optical thin films, etc. Next, a method for manufacturing Example 3 will be described. Furthermore, the method for manufacturing the optical thin film 1 according to the present invention is not limited to the following forms, including the manufacturing apparatus.
[0056] The manufacturing method for Example 3 is the same as that for Example 1, except for the first half. Figure 16 is a schematic diagram showing the first half of the manufacturing method for Example 3. As shown in Figure 16(A), the substrate 2 before film deposition is placed in the vacuum deposition chamber of the sputter deposition apparatus in a horizontal position with the deposition surface F (back surface) facing upwards. Unlike the manufacturing method in Example 1, the mask M is not used in the manufacturing method of Example 3.
[0057] Next, as shown in Figure 16(B), the first thin film portion 10 and then the base film WB removed during cleaning are formed in the same manner as in Example 1, except that there is no mask M. The first thin film portion 10 and the base film WB removed during cleaning are formed on the film-forming surface F of the substrate 2.
[0058] Next, as shown in Figure 16(C), the substrate 2 with the first thin film portion 10 and the base film WB removed during cleaning is removed from the sputtering deposition apparatus, and the laser LA is irradiated onto each of the first thin film portions 10 and each of the base films WB removed during cleaning on the rough surface portion 2R and the peripheral flat portion 2S. The first thin film portions 10 and the base film WB removed during cleaning are removed from the rough surface portion 2R and the peripheral flat portion 2S by irradiation with the laser LA. The first thin film portions 10 and the base film WB removed during cleaning are located only on the lens portion 2L. The output of the laser LA is set to a level that removes the first thin film portion 10 and the base film WB removed during cleaning, without causing any shape changes or other effects on the rough surface portion 2R and the peripheral flat portion 2S beyond a predetermined extent. The output of the laser LA can be adjusted in various ways. For example, if a predetermined amount or less of the remaining first thin film portion 10 and the base film WB removed during cleaning is permitted, the output of the laser LA may be lower than the output required for complete removal. Also, when a shape change (such as the occurrence of fine scratches) below a predetermined extent is permitted, such as when a light-shielding film is formed on the rough surface portion 2R and the peripheral flat portion 2S, the output of the laser LA may be higher than the minimum output required to remove the first thin film portion 10 and the base film WB removed during cleaning. In this way, if the output of the laser LA is higher than the minimum output, the first thin film portion 10 and the base film WB removed during cleaning will be removed more reliably. The laser LA traces over the rough surface 2R and the peripheral flat surface 2S, depending on the size of the spot diameter. For example, the laser LA is irradiated in a state where it scans the rough surface 2R and the peripheral flat surface 2S with a scanning width that is the same as or slightly smaller than the spot diameter. By irradiating with the laser LA in this manner, the removed portions of the first thin film 10 and the base film WB removed during cleaning are patterned, and as a result, the remaining portions of the first thin film 10 and the base film WB removed during cleaning are patterned (Figure 16(D)).
[0059] The substrate 2 having the patterned first thin film portion 10 and the base film WB to be removed during cleaning is then made in the same manner as in Figure 3(C) of Example 1 and subjected to the same processes as in Figure 3(D) and subsequent figures.
[0060] Characteristics of Example 3 To investigate the properties of Example 3 in a more diverse and simpler manner, a sample was prepared in which an optical thin film was formed on a parallel plate substrate 2 using the same manufacturing method as in Example 3. The sample substrate 2 is made of polycarbonate and measures 50 mm in length, 50 mm in width, and 1.0 mm in thickness. Furthermore, the manufacturing method of Example 3 may have modifications similar to those of the manufacturing method of Example 1. Figure 17 is a photograph of the sample. The black areas are the second thin film portion 12 (light-shielding film) and the substrate 2 beneath it, while the other areas are the first thin film portion 10 (AR film) and the substrate 2 beneath it. As shown in Figure 17, optical thin films 1 are formed that are patterned in various shapes, such as black circles, black crosses, white crosses, thick black crosses, thick white crosses, small black rings, and large black rings. Furthermore, the method for manufacturing the optical thin film 1 according to the present invention is not limited to the form of manufacturing the sample. In addition, the method for manufacturing the sample may be modified in the same way as the other manufacturing methods described above.
[0061] The manufacturing of the sample will be explained further. On the entire surface of one side of the parallel plate base material 2, 2The first thin film portion 10 (AR film) is deposited under the conditions shown in Table 6 above (corresponding to Figures 16(A) to (B)). The first thin film portion 10 (AR film) consists of a total of 7 layers, which are alternating layers of SiO2 (odd-numbered layers) and TiO2 (even-numbered layers). The film structure of the first thin film portion 10 (AR film) is shown in Table 7.
[0062] [Table 7]
[0063] Furthermore, an Al layer, which serves as a base film WB to be removed during cleaning, is formed on the entire surface of one side of the substrate 2 with the first thin film portion 10 (AR film) by DC sputtering under the conditions of the fourth row of Table 4 (corresponding to Figure 16(B)).
[0064] Then, patterning is performed by irradiation with a laser LA (corresponding to Figures 16(C)~(D)). Here, the laser LA was emitted using a Keyence MD-X1520 with a wavelength of 1.06 μm, a frequency of 40 kHz (kilohertz), a spot diameter of 80 μm, and a scanning speed of 2000 mm / second. The laser LA was a YAG laser. Scanning was mainly performed by driving a galvanometer mirror. Patterning is performed by scanning the shape corresponding to the second thin film portion 12 (light-shielding film, black area) with a laser. Furthermore, at least one of the following may be changed from those described above: the type of laser LA, various settings, and the patterning shape. In particular, the output of the laser LA should be sufficient to remove the first thin film portion 10 (AR film) and the base film WB removed during cleaning (while appropriately allowing a predetermined residual amount). If overlap between the first thin film portion 10 (AR film) and the second thin film portion 12 (light-shielding film) is permitted, the output of the laser LA should be sufficient to remove the base film WB removed during cleaning. In addition, if overlap between the first thin film portion 10 (AR film) and the second thin film portion 12 (light-shielding film) is permitted, and if a residual amount of the film W removed during cleaning is allowed to be less than a specific amount, the output of the laser LA should be sufficient to remove (partially remove) the base film WB removed during cleaning while leaving a residual amount less than a specific amount.
[0065] Subsequently, as shown in Figures 3(D) to (F), the base film WB removed during cleaning is transformed into a film W having a fuzzy structure, etc., by immersion in hot water HW. Furthermore, as shown in Figure 3(G), a second thin film portion 12 (light-shielding film) is formed on the entire surface of one side of the substrate 2 with the first thin film portion 10 (AR film) and the film removed during cleaning W. The film structure of the second thin film portion 12 (light-shielding film) here is the same as the film structure shown in Table 2 above for Example 1. Then, as shown in Figures 3(H) to (J), a sample having a first thin film portion 10 (AR film) and a second thin film portion 12 (light-shielding film) is formed by immersion in hot water HW and washing with running water, as shown in Figure 3(K).
[0066] Figure 18 is a magnified view of the lower right portion of the black cross shape and the upper right portion of the white cross shape in Figure 17. Figure 19 is a magnified view of the small black ring-shaped portion in Figure 17. Figure 20 is a magnified view (bright-field image from a microscope) of the inner circumference of the lower part of the ring in Figure 19, with the upper part of Figure 20 being the first thin film portion 10 (AR film) and the lower part of Figure 20 being the second thin film portion 12 (light-shielding film). These figures (photographs) show that the patterning is performed to a certain level of quality or higher. Furthermore, the quality of the patterning can be further improved by reducing the spot diameter of the laser LA and reducing the scanning speed, at least one of the above.
[0067] Figure 21 is a graph showing the reflectance distribution in the visible and adjacent regions for the first thin film portion 10 (AR film) and the second thin film portion 12 (light-shielding film) of the sample. This graph shows that the first thin film portion 10 (AR film), which is transparent in the visible range, achieves low reflectivity to visible light. Furthermore, it can be seen that the second thin film portion 12 (light-shielding film), which has a light-shielding function due to light absorption, also possesses an anti-reflective function in the visible range and adjacent ranges.
[0068] Summary etc. The method for producing Example 3 (Sample) is a method for producing an optical thin film 1 having a first thin film portion 10 and a second thin film portion 12 having a different film structure from the first thin film portion 10 on the film deposition surface F of a substrate 2, and includes the steps of: forming a first thin film portion 10 on the first film deposition portion of the film deposition surface F; forming a washable film W on the first thin film portion 10, which is at least one of aluminum and an aluminum compound having a fuzzy structure or the like; forming a second thin film portion 12 on the second film deposition portion of the film deposition surface F that is different from the first film deposition portion, and on the first film deposition portion on which the first thin film portion 10 and the washable film W are formed; and removing the washable film W and the second thin film portion 12 thereon by washing. Therefore, an optical thin film in which the first thin film portion and the second thin film portion are separated can be manufactured at a high quality and low cost without using a resist, a bridging mask MZ, or an organic solvent. Furthermore, the phrase "on top of" the film-forming surface, the first film-forming portion, and the second film-forming portion includes both states where the object is in contact with the film-forming surface, the first film-forming portion, and the second film-forming portion, and states where the object is not in contact with the film-forming surface, the first film-forming portion, and the second film-forming portion, but is separated by an interlayer, yet is located above them.
[0069] In addition, in the process of forming the first thin film portion 10 of Example 3 (Sample), the first thin film portion 10 is formed over the entire film deposition surface F, which includes a portion of the first film deposition portion (Figure 16(A)~(B)), and then the first thin film portion 10 on the portion of the film deposition surface F other than the first film deposition portion (second film deposition portion) is removed by laser LA (Figure 16(C)~(D)). Therefore, the first thin film portion 10 (second thin film portion 12) can be patterned in any shape. Furthermore, when damage to the second film portion, etc., due to removal by laser LA (e.g., clouding, surface roughness, surface dissolution, remaining of at least one of the first thin film portion 10 and the base film WB removed during cleaning) is acceptable, such as when the second thin film portion 12 is a light-shielding film, setting up the laser LA for removal becomes easier, and the optical thin film 1 is manufactured more efficiently. [Explanation of Symbols]
[0070] 1.51...Optical thin film, 2.52...Substrate, 10,60...First thin film portion, 12,62...Second thin film portion, F,F2...Film deposition surface, W...Film removed during cleaning, WB...Base film removed during cleaning.
Claims
1. A method for manufacturing an optical thin film having a first thin film portion and a second thin film portion having a different film structure from the first thin film portion, either directly or via an interlayer on the film deposition surface of a substrate, A step of forming the first thin film portion on the first film-forming portion of the film-forming surface, A step of forming a cleaning removal film on the first thin film portion, which is at least one of aluminum and an aluminum compound having at least one of a fuzzy structure, a pyramidal group structure, and a pincushion structure. A step of forming the second thin film portion on the second thin film portion which is different from the first thin film portion on the film-forming surface, and on the first thin film portion on which the first thin film portion and the film removed during cleaning are formed, A step of removing the aforementioned cleaning-removed film and the second thin film portion thereon by cleaning, including A method for manufacturing an optical thin film, characterized by the following features.
2. The second thin film portion is ring-shaped or frame-shaped. A method for manufacturing an optical thin film according to claim 1.
3. The aforementioned cleaning removal film is formed by immersing a cleaning removal base film, which is formed by a physical vapor deposition method using at least one of aluminum and an aluminum compound as the material, in hot water. A method for manufacturing an optical thin film according to claim 1 or 2.
4. The aforementioned film removed during cleaning and the second thin film portion thereon are cleaned by at least one of running water and ultrasonic waves. A method for manufacturing an optical thin film according to any one of claims 1 to 3.
5. The second thin film portion is a light-shielding film that cuts out visible light. A method for manufacturing an optical thin film according to any one of claims 1 to 4.
6. The first thin film portion is an anti-reflective coating that suppresses the reflection of visible light. A method for manufacturing an optical thin film according to any one of claims 1 to 5.
7. In the step of forming the first thin film portion, the first thin film portion is formed only on the first film-forming portion using a mask. A method for manufacturing an optical thin film according to any one of claims 1 to 6.
8. In the step of forming the first thin film portion, after forming the first thin film portion on the entire or partial surface or interlayer, including a portion of the first film-forming portion, the first thin film portion on the portion of the surface or interlayer other than the first film-forming portion is removed by laser. A method for manufacturing an optical thin film according to any one of claims 1 to 6.