JP5403897B2 - Manufacturing method of color filter for solid-state imaging device - Google Patents

Description

The present invention relates to a method for manufacturing a color filter for a solid-state imaging device using a dry etching method.

  As a method for producing a color filter used for a liquid crystal display device or a solid-state imaging device, a dyeing method, a printing method, an electrodeposition method, and a pigment dispersion method are known.

  Among these, the pigment dispersion method is a method for producing a color filter by a photolithography method using a colored radiation-sensitive composition in which a pigment is dispersed in various photosensitive compositions. It has the advantage of being stable to heat and the like. Further, since patterning is performed by a photolithography method, it has been widely used as a suitable method for manufacturing a color filter for a large-screen, high-definition color display with high positional accuracy.

  When producing a color filter by a pigment dispersion method, a radiation sensitive composition is applied on a glass substrate by a spin coater or a roll coater and dried to form a coating film, and the coating film is subjected to pattern exposure and development. Colored pixels are formed, and a color filter can be obtained by repeating this operation for each color.

  Examples of the pigment dispersion method include a negative photosensitive composition in which a photopolymerizable monomer and a photopolymerization initiator are used in combination with an alkali-soluble resin (see, for example, Patent Documents 1 to 4).

  Furthermore, in order to cope with further higher image quality of the color filter that could not be realized with the negative photosensitive composition, an object is to provide a color filter in which the pixels of the color filter are controlled to a desired size and shape, As the alkali-soluble resin, there is one in which a negative photosensitive composition using an acrylic resin having an alkylene oxide chain and / or hydroxyethyl methacrylate (HEMA) in the molecule is described (for example, see Patent Document 5).

  On the other hand, in recent years, there has been a demand for higher definition in color filters for solid-state imaging devices. In particular, miniaturization of a solid-state imaging device is remarkable, and a high-resolution technique with a size of less than 2.0 μm is required, and the resolution of the conventional photolithographic method is becoming a limit.

In contrast to the color filter manufacturing method using the photolithographic method, a dry etching method has been known for a long time as a method for forming a fine pattern with a thinner film. The dry etching method has been conventionally employed as a method for forming a pattern on a dye-deposited thin film (see, for example, Patent Document 6), and the film is formed with the same spectral characteristics as that of a photolithographic system. A thin film having a thickness of 1/2 or less can also be formed. In addition, a pattern forming method combining a photolithographic method and a dry etching method has been proposed. (For example, refer to Patent Document 7). In addition, a technique for facilitating the peeling of the photoresist by removing the altered surface layer of the photoresist by ashing has been proposed (see, for example, Patent Document 8).
JP-A-2-181704 JP-A-2-199403 Japanese Patent Laid-Open No. 5-273411 JP-A-7-140654 JP 2005-326453 A JP-A-55-146406 JP 2001-249218 A JP 2003-332310 A

  In the production of a color filter using a dry etching method, there is a general tendency that a problem of damage to the support (scraping) due to an over-etching process occurs. For example, when a pattern is formed by removing the colored layer on the support by dry etching, even a part of the support in the region from which the colored layer is removed may be scraped and a step may be generated. In addition, after the etching end point is detected, an over-etching process may be performed to remove residues from the support. In this case, an organic film is present on the support, or an etching gas containing a fluorine-based gas is used. When using the overetching process, it has been difficult to avoid occurrence of damage to the support.

  The present invention has been made in view of the above problems, and an object of the present invention is to provide a method for producing a color filter in which occurrence of damage (scraping) of a support during dry etching is suppressed, and the object is achieved. This is the issue.

Specific means for solving the above problems are as follows.
<1> (a) a colored layer forming step of forming a colored layer on the support; (b) a photoresist layer forming step of forming a photoresist layer on the colored layer; and (c) the photoresist. An image forming step of forming an image on the colored layer by removing the layer in a pattern, and (d) a fluorine-based gas and an oxygen gas content ratio ( A portion of the colored layer is removed within a range where the support is not exposed by dry etching using a first mixed gas having a flow ratio of 2/1 to 8/1 in terms of a flow rate ratio of fluorine gas / oxygen gas). A first etching step for forming a colored layer removal portion in which the thickness of the colored layer is 10% to 20% like the pattern formed by the image forming step; and (e) after the first etching step. Including nitrogen gas and oxygen gas In addition, the colored layer removing portion is formed by a dry etching method using a second mixed gas in which the content ratio of nitrogen gas to oxygen gas (nitrogen gas / oxygen gas) is 10/1 to 3/1 in flow rate ratio. A second etching step of removing at least a part of the substrate to form a support exposed portion like the pattern; and (f) a photoresist layer removing step of removing the photoresist layer remaining after the second etching step. And a method for manufacturing a color filter for a solid-state imaging device.

<2> The method for producing a color filter for a solid-state imaging device according to <1>, wherein the second etching step uses the second mixed gas not containing a fluorine-based gas.

<3> Sidewalls generated in the second etching step by a dry etching method using a third mixed gas containing oxygen gas after the second etching step and before the photoresist layer removing step The method for producing a color filter for a solid-state imaging device according to <1> or <2>, further including a third etching step for removing deposits.
<4> The third mixed gas is a mixed gas of oxygen gas and argon gas, and the content ratio of oxygen gas to argon gas (oxygen gas / argon gas) is 10/800 to 100 in flow rate ratio. / 500. The method for producing a color filter for a solid-state imaging device according to <3>, wherein the color filter is / 500.
< 5 > After the third etching step and before the photoresist layer removing step, a dry etching method using oxygen gas is used to remove the altered layer derived from the sidewall deposit and the photoresist layer. The method for producing a color filter for a solid-state imaging device according to <3> or <4> , further comprising 4 etching steps.

< 6 > The method for producing a color filter for a solid-state imaging device according to any one of <1> to < 5 >, wherein the second etching step further includes an overetching treatment step. .
< 7 > The <1> to < 6, wherein the fluorine-based gas is at least one fluorine-based gas selected from the group consisting of CF ₄ , C ₄ F ₈ , C ₂ F ₆ and CHF _3. > A method for producing a color filter for a solid-state imaging device according to any one of the above.
<8> The first mixed gas is, Ar, He, Kr, further comprising at least one gas selected from the group consisting of _{N 2,} and Xe, Ar, He, Kr, from the group of _{N 2,} and Xe The solid-state imaging according to any one of <1> to < 7 >, wherein the content of at least one selected gas is 25 or less in flow rate ratio when oxygen gas is 1 It is a manufacturing method of the color filter for elements .
< 9 > The second mixed gas further includes at least one gas selected from the group consisting of Ar, He, Kr, and Xe, and at least one selected from the group consisting of Ar, He, Kr, and Xe. The production of a color filter for a solid-state imaging device according to any one of <1> to < 8 >, wherein the gas content is 25 or less in terms of a flow rate ratio when oxygen gas is 1. Is the method.

< 10 > The solid-state imaging device according to any one of <1> to < 9 >, wherein the first etching step has an internal pressure of the chamber of 2.0 to 6.0 Pa . It is a manufacturing method of a color filter.
< 11 > The solid-state imaging device according to any one of <1> to < 10 >, wherein in the second etching step, the internal pressure of the chamber is 1.0 to 4.0 Pa . It is a manufacturing method of a color filter.
< 12 > The temperature of the support in the first etching step and / or the second etching step is 30 ° C. to 100 ° C. Any one of the above <1> to < 11 > The manufacturing method of the color filter for solid-state image sensors as described in a term.

  ADVANTAGE OF THE INVENTION According to this invention, the manufacturing method of the color filter by which generation | occurrence | production of the support body damage (scraping) at the time of a dry etching process was suppressed can be provided.

[Colored layer forming step]
The method for producing a color filter of the present invention includes (a) a colored layer forming step of forming a colored layer on a support.
<Support>
The support in the present invention is not particularly limited as long as it is used for a color filter. For example, soda glass, borosilicate glass, quartz glass, and the like, which are used for liquid crystal display elements, and a transparent conductive film are attached to these. And photoelectric conversion element substrates used for imaging devices and the like, for example, silicon substrates, oxide films, silicon nitride, and the like. Moreover, you may provide other layers, such as an intermediate | middle layer, between these support bodies and a colored layer, unless the effect of this invention is impaired.

<Colored layer>
The colored layer in the present invention can constitute at least one of the pixels of the color filter in the present invention.
The colored layer in the present invention is preferably formed of a curable composition containing a colorant. Examples of the curable composition include a colored photocurable composition and a non-photosensitive colored thermosetting composition. The colored layer in the present invention is preferably formed using a non-photosensitive colored thermosetting composition from the viewpoint of spectral characteristics.

(Colored photocurable composition)
The colored photocurable composition used in the present invention contains at least a colorant and a photocurable component. Among these, the “photo-curable component” is a photo-curable composition usually used in the photolithography method, such as a binder resin (alkali-soluble resin, etc.), a photosensitive polymerization component (photo-photosynthesis monomer, etc.), a photopolymerization initiator. A composition containing at least the above can be used.
For the colored photocurable composition, for example, the matters described in paragraph numbers 0017 to 0064 of JP-A-2005-326453 can be suitably applied.

  The colored layer forming step in the present invention is a step of coating the above-mentioned colored photocurable composition directly on the support or via another layer and then drying to form a coating film (coating layer forming step); And a step of performing a heat treatment (post-bake step).

(Colored thermosetting composition)
In the present invention, a colored layer can be formed using a non-photosensitive colored thermosetting composition. The non-photosensitive colored thermosetting composition in the present invention contains a colorant and a thermosetting compound, and the colorant concentration in the total solid content is 50% by mass or more and less than 100% by mass. preferable.

-Colorant-
The colorant that can be used in the present invention is not particularly limited, and various conventionally known dyes and pigments can be used alone or in combination.

  Examples of the pigment that can be used in the present invention include conventionally known various inorganic pigments or organic pigments. Further, considering that it is preferable to have a high transmittance, whether it is an inorganic pigment or an organic pigment, it is preferable to use a pigment having an average particle size as small as possible, and considering the handling properties, the average particle size of the pigment is 0.01 μm to 0.1 μm is preferable, and 0.01 μm to 0.05 μm is more preferable.

  Examples of pigments that can be preferably used in the present invention include the following. However, the present invention is not limited to these.

C. I. Pigment yellow 11,24,108,109,110,138,139,150,151,154,167,180,185;
C. I. Pigment orange 36, 71;
C. I. Pigment red 122,150,171,175,177,209,224,242,254,255,264;
C. I. Pigment violet 19, 23, 32;
C. I. Pigment blue 15: 1, 15: 3, 15: 6, 16, 22, 60, 66;
C. I. Pigment Black 1

  In the present invention, when the colorant is a dye, it can be uniformly dissolved in the composition to obtain a non-photosensitive thermosetting colored resin composition.

  The dye that can be used as the colorant constituting the composition in the present invention is not particularly limited, and conventionally known dyes for color filters can be used.

  The chemical structure includes pyrazole azo, anilino azo, triphenyl methane, anthraquinone, anthrapyridone, benzylidene, oxonol, pyrazolotriazole azo, pyridone azo, cyanine, phenothiazine, pyrrolopyrazole azomethine, Xanthene-based, phthalocyanine-based, benzopyran-based and indigo-based dyes can be used.

  The colorant content in the total solid content of the colored thermosetting composition in the present invention is not particularly limited, but is preferably 50% by mass or more and less than 100% by mass, and 55% by mass or more and 90% by mass or less. Is more preferable. When the content is 50% by mass or more, an appropriate chromaticity as a color filter can be obtained. Moreover, photocuring can fully be advanced by setting it as less than 100 mass%, and the strength reduction as a film | membrane can be suppressed.

-Thermosetting compound-
The thermosetting compound that can be used in the present invention is not particularly limited as long as the film can be cured by heating. For example, a compound having a thermosetting functional group can be used. As the thermosetting compound, for example, those having at least one group selected from an epoxy group, a methylol group, an alkoxymethyl group, and an acyloxymethyl group are preferable.

  More preferable thermosetting compounds include (a) an epoxy compound, (b) a melamine compound, a guanamine compound, and a glycoluril substituted with at least one substituent selected from a methylol group, an alkoxymethyl group, and an acyloxymethyl group. A compound or a urea compound, (c) a phenol compound, a naphthol compound, or a hydroxyanthracene compound substituted with at least one substituent selected from a methylol group, an alkoxymethyl group, and an acyloxymethyl group. Among these, a polyfunctional epoxy compound is particularly preferable as the thermosetting compound.

  Although the total content of the thermosetting compound in the colored thermosetting composition varies depending on the material, it is preferably 0.1 to 50% by mass with respect to the total solid content (mass) of the curable composition. 0.2-40 mass% is more preferable, and 1-35 mass% is especially preferable.

-Various additives-
In the colored thermosetting composition of the present invention, various additives such as a binder, a curing agent, a curing catalyst, a solvent, a filler, and a high amount other than those described above may be used as long as the effects of the present invention are not impaired. Molecular compounds, surfactants, adhesion promoters, antioxidants, ultraviolet absorbers, aggregation inhibitors, dispersants, and the like can be blended.

~binder~
The binder is often added at the time of preparing the pigment dispersion, does not require alkali solubility, and may be soluble in an organic solvent.

  The binder is preferably a linear organic polymer that is soluble in an organic solvent. Examples of such linear organic high molecular polymers include polymers having a carboxylic acid in the side chain, such as JP-A-59-44615, JP-B-54-34327, JP-B-58-12577, and JP-B-54-. No. 25957, JP-A-59-53836, JP-A-59-71048, methacrylic acid copolymer, acrylic acid copolymer, itaconic acid copolymer, crotonic acid copolymer, etc. Examples thereof include polymers, maleic acid copolymers, partially esterified maleic acid copolymers, and acidic cellulose derivatives having a carboxylic acid in the side chain are also useful.

  Among these various binders, from the viewpoint of heat resistance, polyhydroxystyrene resins, polysiloxane resins, acrylic resins, acrylamide resins, and acrylic / acrylamide copolymer resins are preferable. Acrylic resins, acrylamide resins, and acrylic / acrylamide copolymer resins are preferred.

As the acrylic resin, a copolymer comprising monomers selected from benzyl (meth) acrylate, (meth) acrylic acid, hydroxyethyl (meth) acrylate, (meth) acrylamide, and the like, for example, benzyl methacrylate / methacrylic acid, Each copolymer such as benzyl methacrylate / benzylmethacrylamide, KS resist-106 (manufactured by Osaka Organic Chemical Industry Co., Ltd.), cyclomer P series (manufactured by Daicel Chemical Industries, Ltd.) and the like are preferable.
By dispersing the colorant in these binders at a high concentration, it is possible to impart adhesion to the lower layer and the like, which also contributes to the coated surface shape during spin coating and slit coating.

~ Curing agent ~
In this invention, when using an epoxy resin as a thermosetting compound, it is preferable to add a hardening | curing agent. There are many types of curing agents for epoxy resins, and their properties, pot life with resin and curing agent mixture, viscosity, curing temperature, curing time, heat generation, etc. vary greatly depending on the type of curing agent used. An appropriate curing agent must be selected according to the purpose of use, use conditions, working conditions, and the like. The curing agent is described in detail in Chapter 5 of Hiroshi Kakiuchi “Epoxy resin (Shojodo)”. Examples of the curing agent are as follows.
Those that act catalytically include tertiary amines, boron trifluoride-amine complexes, those that react stoichiometrically with functional groups of epoxy resins, polyamines, acid anhydrides, etc .; Examples include diethylenetriamine, polyamide resin, and medium temperature curing examples such as diethylaminopropylamine and tris (dimethylaminomethyl) phenol; examples of high temperature curing include phthalic anhydride and metaphenylenediamine. In terms of chemical structure, in the case of amines, diethylenetriamine as an aliphatic polyamine; metaphenylenediamine as an aromatic polyamine; tris (dimethylaminomethyl) phenol as a tertiary amine; phthalic anhydride as an acid anhydride; polyamide resin Polysulfide resin, boron trifluoride-monoethylamine complex; Synthetic resin initial condensate includes phenol resin, dicyandiamide and the like.

  These curing agents react with an epoxy group by heating and polymerize to increase the crosslinking density and cure. For thinning, both the binder and the curing agent are preferably as small as possible. In particular, the curing agent is 35% by mass or less, preferably 30% by mass or less, more preferably 25% by mass or less with respect to the thermosetting compound. It is preferable that

~ Curing catalyst ~
In order to achieve a high colorant concentration in the present invention, curing by reaction between epoxy groups is effective in addition to curing by reaction with the curing agent. For this reason, a curing catalyst can be used without using a curing agent. The addition amount of the curing catalyst is about 1/10 to 1/1000, preferably about 1/20 to 1/500, more preferably 1/30, based on the mass of the epoxy resin having an epoxy equivalent of about 150 to 200. It can be cured with a slight amount of about 1/250.
~solvent~
The colored thermosetting composition in the present invention can be used as a solution dissolved in various solvents. Each solvent used in the colored thermosetting composition in the present invention is basically not particularly limited as long as the solubility of each component and the coating property of the colored thermosetting composition are satisfied.

~ Dispersant ~
The dispersant can be added to improve the dispersibility of the pigment. As the dispersant, known ones can be appropriately selected and used, and examples thereof include a cationic surfactant, a fluorosurfactant, and a polymer dispersant.
As these dispersants, many kinds of compounds are used. For example, a phthalocyanine derivative (commercial product EFKA-745 (manufactured by Efka)), Solsperse 5000 (manufactured by Nippon Lubrizol); organosiloxane polymer KP341 (Shin-Etsu) Chemical Industry Co., Ltd.), (meth) acrylic acid (co) polymer polyflow No. 75, No. 90, No. 95 (manufactured by Kyoeisha Chemical Co., Ltd.), W001 (manufactured by Yusho Co., Ltd.), etc. Cationic surfactants of: polyoxyethylene lauryl ether, polyoxyethylene stearyl ether, polyoxyethylene oleyl ether, polyoxyethylene octyl phenyl ether, polyoxyethylene nonyl phenyl ether, polyethylene glycol dilaurate, polyethylene glycol distearate, sorbitan fatty acid Nonionic surfactants such as stealth; Anionic surfactants such as W004, W005 and W017 (manufactured by Yusho Co., Ltd.); EFKA-46, EFKA-47, EFKA-47EA, EFKA polymer 100, EFKA polymer 400, Polymer dispersing agents such as EFKA polymer 401, EFKA polymer 450 (manufactured by Morishita Sangyo Co., Ltd.), Disperse Aid 6, Disperse Aid 8, Disperse Aid 15, Disperse Aid 9100 (manufactured by San Nopco); Solsperse 3000, 5000, 9000, 12000, 13240, 13940, 17000, 24000, 26000, 28000 and other various Solsperse dispersants (manufactured by Nippon Lubrizol); Adeka Pluronic L31, F38, L42, L44, L61, L64, F68, L 2, P95, F77, P84, F87, P94, L101, P103, F108, L121, P-123 (manufactured by Asahi Denka Co.) and Isonetto S-20 (manufactured by Sanyo Chemical Co.) and the like

  The dispersants may be used alone or in combination of two or more. The amount of the dispersant added in the colored thermosetting composition of the present invention is usually preferably about 0.1 to 50 parts by mass with respect to 100 parts by mass of the pigment.

~ Other additives ~
Various additives can be further added to the non-photosensitive colored curable composition of the present invention as necessary. Specific examples of the various additives include, for example, various additives described in JP-A-2005-326453.

The colored layer in the present invention can be formed, for example, by applying the colored thermosetting composition described above to a support and drying it. Specifically, for example, the colored thermosetting composition in the present invention containing a solvent may be formed by coating on a support by a coating method such as spin coating, slit coating, cast coating, roll coating or the like. it can.
The specific thickness of the colored layer is preferably 0.005 μm to 0.9 μm, preferably 0.05 μm to 0.8 μm, and more preferably 0.1 μm to 0.7 μm.

  The colored layer forming step in the present invention preferably further includes a heating step (may be a post-baking step). Specifically, the colored layer can be formed by coating the colored thermosetting composition of the present invention on a support to form a coating film, and then thermally curing the coating film by a heating step. The heating step may be performed at the same time as drying after coating, or a separate thermosetting step may be provided after coating and drying. In the heating step, a known heating means such as an oven or a hot plate is used, preferably 130 to 300 ° C., more preferably 150 to 280 ° C., particularly preferably 170 to 260 ° C., preferably 10 to 10 ° C. Second to 3 hours, more preferably 30 seconds to 2 hours, particularly preferably 60 seconds to 60 minutes. However, considering the production, the time required for curing is preferably as short as possible.

[Photoresist layer forming step]
The method for producing a color filter of the present invention includes (b) a photoresist layer forming step of forming a photoresist layer on the colored layer.
In the method for producing a color filter of the present invention, the colored layer can be formed into a desired shape (for example, a rectangle) by performing an etching process in a later etching process using the photoresist layer as a mask.
As described above, after the colored layer is formed in the colored layer forming step (a) on the support, a photoresist layer (photosensitive resin layer) is further formed on the colored layer. Specifically, a positive or negative photosensitive resin composition is applied on the colored layer and dried to form a photoresist layer. In the formation of the photoresist layer of the present invention, it is preferable to further perform a pre-bake treatment.

As the positive or negative photosensitive resin composition, for example, the matters described in paragraph numbers 0112 to 0117 of JP-A No. 2007-11324 can be suitably applied also in the present invention.
As the coating method of the photosensitive resin composition, the above-described coating method can be suitably used. The specific thickness of the photosensitive resin layer is preferably 0.01 μm to 3 μm, more preferably 0.1 μm to 2.5 μm, and still more preferably 0.15 μm to 2 μm.

  The positive photosensitive resin composition is used for positive photoresists that are sensitive to radiation such as ultraviolet rays (g rays, i rays), deep ultraviolet rays including excimer lasers, electron beams, ion beams, and X rays. Any suitable positive resist composition can be used. Of the radiation, the one that exposes the photosensitive resin layer is preferably g-line or i-line for the purpose of the present invention, and i-line exposure is particularly preferable.

[Image forming process]
The method for producing a color filter of the present invention includes (c) an image forming step of forming an image on the colored layer by removing the photoresist layer in a pattern manner. Here, the colored layer may be composed of a single colored layer or may be composed of two or more kinds of colored layers.

In the present invention, the pattern formed by removing the photoresist layer is a pattern including a region where a second colored layer different from the already formed colored layer (first colored layer) is formed on the support. Preferably there is.
In the image forming step, the photoresist layer is exposed in a desired pattern, for example, a pattern corresponding to a region in which the second colored layer is formed on the support, and is developed with a developing solution to form an etching mask ( Pattern image) can be formed.

By the image forming step, the surface of the first colored layer (surface opposite to the side facing the support) is exposed like the pattern. On the other hand, in the first colored layer, the region other than the region where the second colored layer is formed on the support is in a state covered with the photoresist layer.
In the color filter manufactured by the manufacturing method of the present invention, by forming the second colored layer on the support, in addition to the pixels constituted by the first colored layer, another type of pixel is further added. Can be formed. Since the photoresist layer serving as a mask material can be miniaturized and has rectangularity, each pixel of the color filter manufactured by the manufacturing method of the present invention can be formed in a fine and rectangular shape.

  The photoresist layer is exposed to a positive or negative photosensitive resin composition through a predetermined (image-like) mask pattern, such as g-line, h-line, i-line, preferably i-line. It can be done by applying.

  As the developer, any developer can be used as long as it does not affect the colored layer containing the colorant and dissolves the exposed portion of the positive resist and the uncured portion of the negative resist. Specifically, a combination of various organic solvents or an alkaline aqueous solution can be used.

[First etching step]
In the method for producing a color filter of the present invention, (d) a part of the colored layer is removed in a range where the support is not exposed by a dry etching method using a first mixed gas containing a fluorine-based gas and an oxygen gas. And a first etching step of forming a colored layer removing portion in which the thickness of the colored layer is 10% to 20% like the pattern formed by the image forming step.
Representative examples of the dry etching method include JP-A-59-126506, JP-A-59-46628, JP-A-58-9108, JP-A-58-2809, JP-A-57-148706, JP-A-61-41102. Methods such as those described in publications such as No. are known.

In the present invention, in the (c) image forming step, only the region corresponding to the region where the second colored layer is formed on the support is exposed in the first colored layer. In this state, by performing anisotropic etching by a dry etching method (for example, plasma etching process) using a first mixed gas containing a fluorine-based gas and an oxygen gas, the pattern formed in the image forming process is in, it shall be the first layer 10% to 20% of the thickness of the thickness of the colored layer colored layer partially formed to on the support removal.
Further, in the first etching step, when the colored layer removal portion is formed like the pattern formed in the image forming step, the etching process is terminated before the support is exposed, so that the support damage is reduced. Occurrence can be avoided.

(First mixed gas)
In the present invention, (d) the first mixed gas used in the etching step is at least one fluorine-based gas from the viewpoint that the colored layer portion (the portion to be etched) removed by the dry etching method can be processed into a rectangle. And oxygen gas.

A known fluorine-based gas can be used as the fluorine-based gas, but a fluorine-based compound gas represented by the following formula (I) is preferable.
C _n H _m F _l Formula (I)
[In formula, n represents 1-6, m represents 0-13, and l represents 1-14. ]

Examples of the fluorine-based gas represented by the formula (I) include CF ₄ , C ₂ F ₆ , C ₃ F ₈ , C ₂ F ₄ , C ₄ F ₈ , C ₄ F ₆ , C ₅ F ₈ , Mention may be made of at least one selected from the group of CHF ₃ . As the fluorine-based gas in the present invention, one kind of gas can be selected from the above group, and two or more kinds of gases can be used in combination.
The fluorine-based gas in the present invention is preferably at least one selected from the group of CF ₄ , C ₂ F ₆ , C ₄ F ₈ , and CHF ₃ from the viewpoint of maintaining the rectangularity of the etched portion. ₄ and / or C ₂ F ₆ is more preferable, and CF ₄ is particularly preferable.

The first mixed gas in the present invention, the content ratio (fluorine-based gas / oxygen gas) with the fluorine-based gas and oxygen gas is 2 / 1-8 / 1 at a flow rate ratio. By setting it within the above range, it is possible to prevent the etching product from adhering to the sidewall of the photoresist layer during the etching process, and the photoresist layer can be easily peeled off in the photoresist layer removing step described later. In particular, the content ratio of the fluorine-based gas and the oxygen gas is 2/1 to 6/1 in terms of preventing the re-deposition of the etching product to the photoresist sidewall while maintaining the rectangularity of the etched portion. It is preferable that the ratio is 3/1 to 5/1.

In the present invention, the first mixed gas is further made of helium (in addition to the fluorine-based gas and oxygen gas) in addition to the fluorine-based gas and the oxygen gas from the viewpoint of maintaining the partial pressure control stability of the etching plasma and the perpendicularity of the shape to be etched. He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe) and other rare gases, and halogen gases containing halogen atoms such as chlorine atoms, fluorine atoms, bromine atoms (for example, CCl ₄ , CClF ₃ , AlF ₃ , AlCl _3, etc.), preferably N ₂ , CO, and CO ₂ , preferably at least one selected from the group of Ar, He, Kr, N ₂ , and Xe It is more preferable that 1 type is included, and it is still more preferable that at least 1 type chosen from the group of He, Ar, and Xe is included.
However, in the case where it is possible to maintain the partial pressure control stability of the etching plasma and the perpendicularity of the shape to be etched, the first mixed gas may consist only of a fluorine-based gas and an oxygen gas.
In the first mixed gas in the present invention, the content of other gases that may be contained in addition to the fluorine-based gas and the oxygen gas is preferably 25 or less in terms of a flow rate ratio when the oxygen gas is 1. It is more preferably 10 or more and 20 or less, and particularly preferably 14 or more and 18 or less.

The colored layer removing portion is formed by removing a part of the colored layer formed on the support by a dry etching method. That is, when the dry etching process using the first mixed gas is performed on the colored layer exposed like the pattern, the dry etching process is finished before the support under the colored layer is exposed. Thereby, the colored layer removal part from which a part of colored layer was removed can be formed.
In order to end the dry etching process before the support is exposed, it is preferable to end the dry etching process after a predetermined processing time has elapsed since the start of the dry etching process. The processing time of the dry etching process can be calculated by, for example, the following “calculation method of etching processing time”.
The thickness of the colored layer removal portion in the present invention is set to a thickness of 10 % to 20% of the thickness of the colored layer formed on the support in terms of maintaining pattern rectangularity.

(Etching processing time calculation method)
In the first etching step of the present invention, it is preferable to obtain the etching processing time in advance by the following method.
1) The etching rate (nm / min.) In the first etching step is calculated.
2) A processing time required to etch a desired thickness in the first etching step is calculated from the etching rate calculated above.

The etching rate can be calculated, for example, by collecting data indicating the relationship between the etching time and the remaining film.
In the present invention, the etching treatment time is preferably 10 minutes or less, more preferably 7 minutes or less.

(Internal pressure of chamber)
In the first etching step of the present invention, the internal pressure of the chamber is preferably 2.0 to 6.0 Pa, and more preferably 4.0 to 5.0 Pa. When the internal pressure of the chamber is within the above range, the rectangularity of the pattern is improved, and adhesion of the sidewall protective film generated by etching to the photoresist can be suppressed.
The internal pressure of the chamber can be adjusted, for example, by appropriately controlling the flow rate of the etching gas and the degree of decompression of the chamber.

(Support temperature)
In the first etching step of the present invention, the temperature of the support is preferably 30 ° C. or higher and 100 ° C. or lower. Thereby, adhesion of the etching product to the side wall of the photoresist layer during the etching process can be further suppressed, and peeling of the photoresist layer in the photoresist layer removing step described later can be facilitated. Among these, the support temperature is more preferably 30 ° C. to 80 ° C., and more preferably 40 ° C. to 60 ° C. from the viewpoint of maintaining the rectangularity of the etched portion and suppressing the reattachment of the etching product to the photoresist layer side wall. It is particularly preferable that the temperature is C.
In the first etching step, for example, the temperature of the support can be set to 30 ° C. or more and 100 ° C. or less by controlling the temperature of the wafer stage to 30 ° C. or more and 100 ° C. or less.

(Other conditions)
The dry etching conditions in the first etching step vary depending on the material of the colored layer, the layer thickness, and the like, but preferable conditions other than the above conditions will be described below.
1) The gas flow rate of the first mixed gas in the present invention is preferably 1500 mL / min (0 ° C., 1013 hPa) or less, and more preferably 500 to 1000 mL / min (0 ° C., 1013 hPa).
2) The high frequency can be selected from 400 kHz, 60 MHz, 13.56 MHz, 2.45 GHz, etc., and can be processed with an RF power of 50 to 2000 W, preferably 100 to 1000 W.
3) Regarding the relationship between source power (RF) and bias, RF power / antenna bias / substrate bias (wafer bias) is preferably 600 to 1000 W / 300 to 500 W / 150 to 250 W, and more preferably 700. It is -900W / 350-450 / 200W.

[Second etching step]
In the color filter manufacturing method of the present invention, after (d) the first etching step, at least a part of the colored layer removing portion is formed by a dry etching method using a second mixed gas containing nitrogen gas and oxygen gas. And a second etching step of forming a support exposed portion like the pattern.
As described above, the colored layer removing portion is formed in the region on the support where the second colored layer is formed by the first etching step, and the other regions on the support are covered with the photoresist layer. A colored layer is formed. In this state, the colored layer formed on the support is removed by performing anisotropic etching by a dry etching method (for example, plasma etching process) using a second mixed gas containing nitrogen gas and oxygen gas. Part or all of the portion is removed, and the support exposed portion can be formed like the pattern.

Conventionally, in an etching process for removing the colored layer in a pattern, if the etching process is performed using the first mixed gas until the support is exposed, the support tends to be damaged. Further, the generated support damage was particularly remarkable when an overetching process was performed. On the other hand, in the present invention, a colored layer removing portion is formed in which the thickness of the colored layer formed on the support in the first etching step is set to a thickness in the range of 10% to 20% of the original. And an etching process in which the occurrence of damage to the support is suppressed by performing the second etching step using a second mixed gas containing nitrogen gas and oxygen gas, which is different from the first mixed gas used. Is possible.

(Second mixed gas)
Although the 2nd mixed gas in this invention contains nitrogen gas and oxygen gas, it may contain fluorine-type gas in the range which does not impair the effect of this invention. The content ratio of the fluorine-based gas (fluorine-based gas / oxygen gas) is preferably 5% or less in terms of flow rate ratio, and particularly preferably does not contain the fluorine-based gas. When the content of the fluorine-based gas is within the above range, damage to the support can be more effectively suppressed.
The content ratio of nitrogen gas and oxygen gas in the second mixed gas (nitrogen gas / oxygen gas), a flow rate ratio of 10 / 1-3 / 1. By making it within the above range, it is possible to more effectively suppress the adhesion of the etching product to the side wall of the photoresist layer during the etching process, and the peeling of the photoresist layer in the photoresist layer removing step described later can be further suppressed. Can be easily. The content ratio is preferably 20/1 to 3/1 from the viewpoint of maintaining the rectangularity of the portion to be etched and preventing the redeposition of the etching product to the side wall of the photoresist layer, and 15/1 to 4 / 1 is more preferable, and 10/1 to 5/1 is particularly preferable.

In the present invention, the second mixed gas is further made of helium (He) as another gas in addition to the nitrogen gas and the oxygen gas from the viewpoint of maintaining the partial pressure control stability of the etching plasma and maintaining the perpendicularity of the shape to be etched. ), Neon (Ne), argon (Ar), krypton (Kr), and xenon (Xe), and preferably contains at least one gas selected from the group consisting of He, Ar, and Xe. More preferably, it contains at least one gas.
However, when it is possible to maintain the partial pressure control stability of the etching plasma and the perpendicularity of the shape to be etched, the second mixed gas can be composed of only nitrogen gas and oxygen gas.
In the second mixed gas, in addition to the nitrogen gas and the oxygen gas, the content of other gases that may be further contained is preferably 25 or less in terms of a flow rate ratio when the oxygen gas is 1. It is preferably 20 or more and particularly preferably 8 or more and 12 or less.

In the second etching processing step of the present invention, for example, after the processing time calculated in the same manner as the “method for calculating the etching processing time” has elapsed since the start of the dry etching processing for removing the colored layer removal portion, dry etching is performed. Processing can be terminated. Moreover, you may manage the dry etching processing time which removes a colored layer removal part by endpoint detection. In the second etching process in the present invention, it is preferable to manage the dry etching process time for removing the colored layer removal portion by detecting the end point.
The etching processing time is preferably within 10 minutes, more preferably within 7 minutes.

  The second etching step in the present invention preferably further includes an overetching treatment step. After removing the colored layer removal portion by dry etching using the second mixed gas and forming the support exposed portion, the remaining etching residue is further removed by over-etching using the second mixed gas. Further, it can be efficiently removed while maintaining the rectangularity of the pattern, and the occurrence of damage to the support can be more effectively suppressed.

The overetching process is preferably performed by setting an overetching time. Although the over-etching time can be set arbitrarily, the etching process time (t ₁ ) in the first etching step and the colored layer in the second etching step are the points of maintaining the etching resistance of the photoresist and the rectangularity of the pattern to be etched. The total processing time (t ₁ + t ₂ ) with the etching processing time (t ₂ ) for removing the removed portion is preferably 30% or less, more preferably 5 to 25%, and more preferably 15 to 20%. It is particularly preferred.

(Internal pressure of chamber for dry etching)
In the present invention, in the second etching step, the internal pressure of the chamber is preferably 1.0 to 5.0 Pa, and more preferably 2.0 to 4.0 Pa.
A pattern in which the occurrence of damage to the support is suppressed can be more efficiently formed without impairing the rectangularity of the pattern under conditions that satisfy the mixing ratio of the mixed gas and the internal pressure of the chamber.

  The high frequency in the second etching step can be selected from 400 kHz, 60 MHz, 13.56 MHz, 2.45 GHz, and the like, for example, processing with RF power of 50 to 2000 W, preferably with RF power of 100 to 1000 W. Can do.

Regarding the relationship between the source power (RF) and the bias in the second etching step, the RF power / antenna bias / substrate bias is preferably 400 to 800 W / 50 to 200 W / 100 to 300 W, more preferably 500, respectively. It is -700W / 100-150W / 200-300W.
Regarding the support temperature and other conditions during the etching process in the second etching process, the matters described in the first etching process can be suitably applied.

[Third etching step]
In the present invention, after the second etching step and before the photoresist layer removing step, which will be described later, it is generated in the second etching step by a dry etching method using a third mixed gas containing oxygen gas. It is preferable to further include a third etching step for removing the side wall deposit. Thereby, the side wall deposit which may be produced | generated by a 2nd etching process and the residue on a support body can be removed effectively.
The term “side wall deposit” as used herein means a nitride or oxynitride etching product generated by an etching process, which is deposited on the side wall of the colored layer formed around the exposed portion of the support. When a large amount of side wall deposits adhere, it is effective to perform the third etching step in the present invention in order to deteriorate the spectral performance. In addition, the third etching process can be performed continuously in the same chamber after the second etching process, or can be performed discontinuously in another chamber. In terms of production efficiency, it is preferable to perform continuous treatment in the same chamber.

(Third mixed gas)
The third mixed gas in the present invention contains oxygen gas. The third mixed gas preferably contains another gas for the purpose of maintaining the perpendicularity of the shape to be etched. The other gas is preferably at least one selected from the group consisting of helium (He), neon (Ne), argon (Ar), krypton (Kr), and xenon (Xe), more preferably helium (He). And / or argon (Ar), more preferably argon (Ar).

The oxygen gas content ratio (oxygen gas / other gas) is preferably 10/800 or more and 100/100 or less, more preferably 4/100 or more and 20/100 or less in terms of a flow rate ratio. When the content ratio of the oxygen gas is within the above range, the verticality of the shape to be etched is maintained, and the product deposited on the side wall of the colored layer to be etched and the residue on the support in the second etching step are more effective. Can be removed.
The third mixed gas in the present invention is particularly preferably a gas composed of oxygen and argon and mixed in the range of oxygen / argon = 10/800 to 100/500.

(Other conditions)
In the third etching step of the present invention, the internal pressure of the chamber is preferably 1.0 to 5.0 Pa, and more preferably 2.0 to 4.0 Pa.
In addition, the high frequency in the third etching step can be selected from 400 kHz, 60 MHz, 13.56 MHz, 2.45 GHz, and the like, for example, processing with an RF power of 50 to 2000 W, preferably with an RF power of 100 to 1000 W. can do.
Furthermore, as a relationship between the source power (RF) and the bias, the RF power / antenna bias / substrate bias (wafer bias) is preferably 300 to 800 W / 50 W to 500 W / 50 to 600 W, more preferably 300, respectively. It is -500W / 100W / 100W-150W.

The etching time in the third etching step is in the range of 10% to 30% of the total etching time, which is the sum of the etching time in the first etching step and the etching time in the second etching step. It is preferable. By performing the treatment in the above range, the verticality of the shape to be etched can be maintained, and the product deposited on the side wall of the colored layer to be etched and the residue on the support can be effectively removed.
In the present invention, instead of performing the overetching process in the second etching step, the overetching process can be performed in the third etching process. By performing the over-etching process using the third mixed gas, it is possible to more effectively suppress the occurrence of support damage.

[Fourth etching step]
In the present invention, after the third etching step and before the photoresist layer removing step described later, the altered layer derived from the sidewall deposit and the photoresist layer is formed by a dry etching method using oxygen gas. It is preferable to further include a fourth etching step for removing. This effectively removes the sidewall deposits that may be generated by the second etching process and the altered layer caused by the plasma formed on the surface layer of the photoresist layer during the first to third etching processes. Can be removed. Furthermore, sidewall deposits generated by the second etching step and residues on the support can be effectively removed.
By removing the altered layer formed on the surface layer of the photoresist layer, it is possible to more easily remove the photoresist layer using a stripping solution or a solvent described later. In the fourth etching step, after the third etching step, the continuous processing can be performed in the same chamber or the discontinuous processing can be performed in another chamber. From the viewpoint of production efficiency, it is preferable to perform continuous processing in the same chamber.

The fourth etching step in the present invention is characterized by using oxygen gas. The purity of the oxygen gas used is preferably 90% or more, and more preferably 99% or more.
The gas flow rate of oxygen gas in the etching process is preferably 10 to 100 ml / min.

In the present invention, the internal pressure of the chamber in the fourth etching step is preferably 1.0 to 5.0 Pa, and more preferably 2.0 to 4.0 Pa.
In addition, the high frequency in the third etching step can be selected from 400 kHz, 60 MHz, 13.56 MHz, 2.45 GHz, and the like, for example, processing with an RF power of 50 to 2000 W, preferably with an RF power of 100 to 1000 W. can do.
Furthermore, as a relationship between the source power (RF) and the bias, the RF power / antenna bias / substrate bias (wafer bias) is preferably 200 to 400 W / 50 W to 300 W / 50 to 300 W, more preferably 300, respectively. It is -350W / 100W / 100W-150W.

  In the present invention, the etching time in the fourth etching step is an etching time in which the altered layer caused by the plasma formed on the surface of the photoresist layer can be removed in the first to third etching steps. preferable. Specifically, the etching processing time is preferably within 15 seconds, and more preferably within 5 seconds.

[Photoresist layer removal step]
The method for producing a color filter of the present invention includes (f) a photoresist layer removing step of removing the photoresist layer remaining after the second etching step.
After completion of the etching process, the mask resist (photosensitive resin layer after curing) is removed with a special stripping solution or solvent.
In the present invention, by further performing the fourth etching step using oxygen gas, it is possible to more easily remove the photoresist layer with a remover or a solvent.

The photoresist layer removing step in the present invention includes (1) a step of applying a stripping solution or a solvent on the photoresist layer to make the photoresist layer removable, and (2) the photoresist layer, And removing with washing water.
As a process of applying a stripping solution or solvent on the photoresist layer to make it removable, for example, a paddle development process in which the stripping solution or solvent is applied on at least the photoresist layer and stagnated for a predetermined time. Can be mentioned. Although there is no restriction | limiting in particular as time to make stripping solution or a solvent stagnant, It is preferable that it is several dozen seconds to several minutes.

The step of removing the photoresist layer using cleaning water includes, for example, a step of removing the photoresist layer by spraying cleaning water onto the photoresist layer from a spray type or shower type spray nozzle. Can do.
As the washing water, pure water can be preferably used.
Further, examples of the injection nozzle include an injection nozzle in which the entire support is included in the injection range, and an injection nozzle that is a movable injection nozzle and in which the movable range includes the entire support. When the spray nozzle is movable, the photoresist layer is more effectively removed by moving the support from the center of the support to the end of the support more than twice during the step of removing the photoresist layer and spraying the cleaning water. Can be removed.

The stripping solution generally contains an organic solvent, but may further contain an inorganic solvent. Examples of organic solvents include 1) hydrocarbon compounds, 2) halogenated hydrocarbon compounds, 3) alcohol compounds, 4) ether or acetal compounds, 5) ketones or aldehyde compounds, and 6) ester compounds. 7) polyhydric alcohol compounds, 8) carboxylic acids or acid anhydride compounds thereof, 9) phenol compounds, 10) nitrogen compounds, 11) sulfur compounds, and 12) fluorine compounds.
The stripping solution in the present invention preferably contains a nitrogen-containing compound, and more preferably contains an acyclic nitrogen-containing compound and a cyclic nitrogen-containing compound.

The acyclic nitrogen-containing compound is preferably an acyclic nitrogen-containing compound having a hydroxyl group. Specific examples include monoisopropanolamine, diisopropanolamine, triisopropanolamine, N-ethylethanolamine, N, N-dibutylethanolamine, N-butylethanolamine, monoethanolamine, diethanolamine, triethanolamine and the like. Monoethanolamine, diethanolamine, triethanolamine, and more preferably monoethanolamine (H ₂ NCH ₂ CH ₂ OH).

  Examples of the cyclic nitrogen-containing compound include isoquinoline, imidazole, N-ethylmorpholine, ε-caprolactam, quinoline, 1,3-dimethyl-2-imidazolidinone, α-picoline, β-picoline, γ-picoline, 2-pipecoline, 3-pipecoline, 4-pipecoline, piperazine, piperidine, pyrazine, pyridine, pyrrolidine, N-methyl-2-pyrrolidone, N-phenylmorpholine, 2,4-lutidine, 2,6-lutidine and the like are preferable, N-methyl-2-pyrrolidone and N-ethylmorpholine are preferable, and N-methyl-2-pyrrolidone (NMP) is more preferable.

The stripping solution in the present invention preferably contains an acyclic nitrogen-containing compound and a cyclic nitrogen-containing compound, and among them, as the acyclic nitrogen-containing compound, at least one selected from monoethanolamine, diethanolamine and triethanolamine More preferably, the cyclic nitrogen-containing compound includes at least one selected from N-methyl-2-pyrrolidone and N-ethylmorpholine, and further includes monoethanolamine and N-methyl-2-pyrrolidone. preferable.
The content of the acyclic nitrogen-containing compound is 9 parts by mass or more and 11 parts by mass or less with respect to 100 parts by mass of the stripping solution, and the content of the cyclic nitrogen-containing compound is 65 parts by mass or more and 70 parts by mass or less. It is desirable.
Moreover, it is preferable that the stripping solution in the present invention is obtained by diluting a mixture of a non-cyclic nitrogen-containing compound and a cyclic nitrogen-containing compound with pure water.

  In the photoresist layer removing step in the present invention, it is only necessary that the photoresist layer formed on the colored layer is removed, and a deposit as an etching product adheres to the side wall of the colored layer. However, the deposit may not be completely removed. Here, the deposit means an etching product deposited on the side wall of the colored layer.

  In the method for producing a color filter of the present invention, the colored layer and the support exposed portion are formed in a pattern on the support as described above. By forming a colored layer different from the colored layer already formed on the exposed portion of the support, for example, a two-color color filter can be manufactured. Further, (b) photoresist layer formation step to (f) photoresist layer removal step in this invention are performed in this order, and then a colored layer is newly formed on the formed support exposed portion, for example, three colors The color filter can be manufactured.

Hereinafter, one aspect of a method for producing a color filter of the present invention will be described with reference to the drawings.
(A) Colored layer forming step As shown in FIG. 1, a colored thermosetting composition corresponding to a predetermined color component is applied to the surface of the support 1 with a desired film thickness, and a post-baking treatment is performed for coloring. Layer 2 is formed.

(B) Photoresist Layer Formation Step As shown in FIG. 2, a positive or negative photoresist composition is applied on the colored layer 2 and prebaked to form a photoresist layer 3 having a desired film thickness.

(C) Image forming step As shown in FIG. 3, the photoresist layer 3 is exposed through a photomask having an opening region corresponding to a predetermined filter array (pixel group) composed of the second colored layer. Then, the latent image area 4 is formed.
FIG. 4 shows a state after the photoresist layer portion of the latent image region 4 to be removed is removed by development processing. A colored layer exposed portion 5 from which the photoresist layer is removed is formed on the support, and this colored layer exposed portion 5 corresponds to a region where the colored layer 2 (first colored layer) is to be removed. The photoresist layer is removed only in a region where a colored layer (second colored layer) different from the colored layer 2 is formed, and the photoresist on the colored layer on which the colored layer 2 and the third and subsequent colored layers are formed. Layer 3 is left.

(D) First Etching Step Next, as shown in FIG. 5, a first etching process is performed using the photoresist layer 3 as a mask to remove a part of the colored layer 2. The etching process is terminated before the support under the colored layer 2 is exposed, and the colored layer removing portion 6 is formed in a region on the support on which the second colored layer is formed. At this time, the colored layer removing unit 6 is in a state of being formed on the support 1 as a thin film in which a portion of the colored layer 2 close to the support is left.

(E) Second Etching Step Next, as shown in FIG. 6, the second etching process is performed using the photoresist layer 3 as a mask, and the colored layer removing portion 6 is removed to form the second colored layer. (Support exposed part 7) is formed.

(F) Photoresist layer removing step After performing the etching process, the photoresist layer 3 is dissolved and removed with a stripping solution or the like. After the completion of the photoresist layer removal step, as shown in FIG. 7, the support exposed by etching is in a flat surface state that is not scraped and has no damage.

  The color filter produced by the production method of the present invention can be used for a solid-state imaging device such as a liquid crystal display device or a CCD, and is particularly suitable for a high-resolution CCD device or a CMOS having more than 1 million pixels. The color filter of the present invention can be used as, for example, a color filter disposed between a light receiving portion of each pixel constituting a CCD and a microlens for condensing light.

  In the method for producing a color filter of the present invention, the first etching step uses a first mixed gas containing a fluorine-based gas and an oxygen gas to perform a dry etching process to remove a part of the colored layer for coloring. Dry etching is performed by forming a layer removing portion and performing a dry etching process using a second mixed gas containing nitrogen gas and oxygen gas in the second etching step to remove the colored layer removing portion. It has become possible to suppress the occurrence of support damage due to the treatment. In addition, when the dry etching method using the mixed gas in the present invention is used, adhesion of the sidewall protective film produced by etching to the photoresist can be suppressed, and the photoresist layer remaining after the dry etching process can be peeled off. It became possible to do it easily. Further, by removing the colored layer by dry etching, it becomes possible to form a rectangular pattern while maintaining the pattern anisotropy. Thus, if the method for producing a color filter of the present invention is used, the occurrence of support damage is suppressed, and a color filter having a very high pattern rectangularity can be produced, which is very useful.

  EXAMPLES The present invention will be specifically described below with reference to examples, but the present invention is not limited to these examples.

  In each of the following steps, when processing using a commercially available processing solution was performed, each processing was performed according to the method specified by the manufacturer unless otherwise specified.

Example 1
[(A) Colored layer forming step]
SG-5000L manufactured by Fuji Film Electronics Materials Co., Ltd. was applied on a silicon wafer with a spin coater (Mark 8 manufactured by Tokyo Electron) so as to form a coating film having a thickness of 0.8 μm. Using a hot plate, heating was performed at 220 ° C. for 5 minutes to cure the coating film and form a colored layer. The thickness of the colored layer formed from the pigment-containing thermosetting composition (colored thermosetting composition) was 0.6 μm.

[(B) Photoresist layer forming step]
Next, a positive photoresist “FHi622BC” (manufactured by FUJIFILM Electronics Materials Co., Ltd.) is applied on the SG-5000L with a spin coater (manufactured by Tokyo Electron, Mark 8), and heat treatment is performed at 100 ° C. for 2 minutes. A photoresist layer was formed so that the film thickness was 0.8 μm.

[(C) Image forming step]
Next, the area corresponding to the filter array of RED was subjected to pattern exposure of 350 mJ / cm ² using an i-line stepper (manufactured by Canon Inc., FPA3000i5 +), heat-treated at 110 ° C. for 1 minute, and then developed. After developing for 1 minute with the liquid “FHD-5” (manufactured by FUJIFILM Electronics Materials), a post-baking process is performed at 120 ° C. for 2 minutes to form a photoresist in the region where the RED filter array is to be formed. This was removed to form an island pattern having a size of 1.5 μm × 1.5 μm.

[(D) First etching step]
Next, RF power: 800 W, antenna bias: 400 W, wafer bias: 200 W, chamber internal pressure: 4.0 Pa, substrate temperature: 50 ° C., mixing in dry etching apparatus (U-621, manufactured by Hitachi High-Technologies Corporation) The gas type and flow rate of the gas were set to CF ₄ : 200 mL / min. , O ₂ : 50 mL / min. , Ar: 800 mL / min. And an etching process for 90 seconds was performed.
The etching rate of SG-5000L under the above-described etching conditions is 326 nm / min, and the shaving amount of the colored layer is 489 nm. Therefore, in the first etching step, 81.5% of the thickness of the colored layer formed of SG-5000L is removed, and an SG-5000L residual film (colored layer removing portion) having a thickness of 111 nm is formed on the support. It was done.

[(E) Second etching step]
Next, in a dry etching apparatus (U-621, manufactured by Hitachi High-Technologies Corporation), RF power: 600 W, antenna bias: 100 W, wafer bias: 250 W, chamber internal pressure: 2 Pa, substrate temperature: 50 ° C., mixed gas The gas type and flow rate were set at N ₂ : 500 mL / min. , O ₂ : 50 mL / min. , Ar: 500 mL / min. (N ₂ / O ₂ / Ar = 10/1/10), and the etching process was performed with the over-etching rate in the total etching being 20%.
The etching rate under the second etching condition was 700 nm / min, and it took about 9.5 seconds to etch the SG-5000L residual film. The sum of the first etching time of 90 seconds and the second etching time of 9.5 seconds was calculated as the total processing time (total etching time). As a result, the total etching time was 90 + 9.5 = 99.5 seconds, and the over-etching time was 99.5 × 0.2 = 19.9 seconds. The etching process was performed with the total etching time set to 99.5 + 19.9 = 1119.4 seconds.

[(F) Photoresist layer removal step]
Next, using a photoresist stripping solution “MS-230C” (manufactured by FUJIFILM Electronics Materials Co., Ltd.), the stripping treatment was performed for 120 seconds to remove the photoresist.
As described above, a color filter pattern was formed to produce a single color filter.

(Example 2)
A monochromatic color filter was produced in the same manner as in Example 1 except that (e) part of the etching conditions in the second etching step in Example 1 was changed to the following conditions.
RF power: 600 W, antenna bias: 150 W, chamber internal pressure: 2 Pa, substrate temperature: 50 ° C., mixed gas type and flow rate are N ₂ : 400 mL / min. , O ₂ : 50 mL / min. , Ar: 500 mL / min. (N ₂ / O ₂ / Ar = 8/1/10). The etching rate at this time was 760 nm / min, and it took about 8.7 seconds to etch the remaining film of SG-5000L. The total etching time was calculated by adding the first etching time of 90 seconds and the second etching time of 8.7 seconds. As a result, the total etching time was 90 + 8.7 = 98.7 seconds, and the over-etching time was 98.7 × 0.2 = about 19.7 seconds. The etching process was performed with the total etching time set to 98.7 + 19.7 = 18.4 seconds.

(Example 3)
A monochromatic color filter was produced in the same manner as in Example 1 except that (e) part of the etching conditions in the second etching step in Example 1 was changed to the following conditions.
RF power: 600 W, antenna bias: 150 W, chamber internal pressure: 2 Pa, substrate temperature: 50 ° C., gas type and flow rate of mixed gas are set to N ₂ : 300 mL / min. , O ₂ : 50 mL / min. , Ar: 500 mL / min. (N ₂ / O ₂ / Ar = 6/1/10), the etching rate at this time was 815 nm / min, and it took about 8.2 seconds to etch the SG-5000L residual film. . The sum of the first etching time 90 seconds and the second etching time 8.2 seconds was calculated as the total etching time. As a result, the total etching time was 90 + 8.2 = 98.2 seconds, and the over-etching time was 98.2 × 0.2 = about 19.6 seconds. The etching process was performed with the total etching time set to 98.2 + 19.6 = 117.8 seconds.

Example 4
A monochromatic color filter was produced in the same manner as in Example 1 except that (e) part of the etching conditions in the second etching step in Example 1 was changed to the following conditions.
RF power: 600 W, antenna bias: 150 W, chamber internal pressure: 2 Pa, substrate temperature: 50 ° C., gas type and flow rate of mixed gas are set to N ₂ : 200 mL / min. , O ₂ : 50 mL / min. , Ar: 500 mL / min. (N ₂ / O ₂ / Ar = 4/1/10), the etching rate at this time was 860 nm / min, and it took about 7.7 seconds to etch the SG-5000L residual film. . The total etching time was calculated by adding 90 seconds of the first etching time and 7.7 seconds of the second etching time. As a result, the total etching time was 90 + 7.7 = 97.7 seconds, and the over-etching time was 97.7 × 0.2 = about 19.5 seconds. The etching process was performed with the total etching time set to 97.7 + 19.5 = 17.2 seconds.

( Reference Example 5)
A monochromatic color filter was produced in the same manner as in Example 1 except that (e) part of the etching conditions in the second etching step in Example 1 was changed to the following conditions.
RF power: 600 W, antenna bias: 150 W, chamber internal pressure: 2 Pa, substrate temperature: 50 ° C., gas type and flow rate of mixed gas are set to N ₂ : 100 mL / min. , O ₂ : 50 mL / min. , Ar: 500 mL / min. (N ₂ / O ₂ / Ar = 2/1/10), and the etching rate at this time was 890 nm / min, and it took about 7.5 seconds to etch the SG-5000L residual film. . The total etching time was calculated by adding 90 seconds of the first etching time and 7.5 seconds of the second etching time. As a result, the total etching time was 90 + 7.5 = 17.5 seconds, and the over-etching time was 97.5 × 0.2 = 19.5 seconds. The etching process was performed with the total etching time set to 97.5 + 19.5 = 117 seconds.

(Examples 6 to 10)
A monochromatic color filter was produced in the same manner as in Example 1 except that (e) part of the etching conditions in the second etching step in Example 1 was changed to the following conditions.
RF power: 600 W, antenna bias: 150 W, chamber internal pressure was changed to 1.0, 3.0, 4.0, 6.0, 8.0 Pa, respectively.
The etching rate and total etching time at each internal pressure were as follows.
-Example 6 (1.0 Pa) Etching rate: 680 nm / min, Remaining film etching time: 9.7 seconds, Total etching time: (90 + 9.7) x 1.2 = 119.6 seconds-Example 7 (2 Etching rate: 710 nm / min, remaining film etching time: 9.4 seconds, total etching time: (90 + 9.4) × 1.2 = 119.3 seconds Example 8 (4.0 Pa) Etching rate: 725 nm / min, remaining film etching time: 9.2 seconds, total etching time: (90 + 9.2) × 1.2 = 119.0 seconds Example 9 (6.0 Pa) Etching rate: 735 nm / min, remaining film Etching time: 9.1 seconds, total etching time: (90 + 9.1) × 1.2 = 119.0 seconds Example 10 (8.0 Pa) Etching rate: 740 nm / min Quenching time: 9 seconds, the total etching time: (90 + 9) × 1.2 = 119.0 seconds

(Examples 11-14)
Example 1 except that the substrate temperature was changed to 30 ° C., 70 ° C., 100 ° C., and 120 ° C. in the etching conditions of (d) the first etching step and (e) the second etching step in Example 1, respectively. In the same manner as in Example 1, a monochromatic color filter was produced.
The etching rate at each temperature and the total etching time were as follows.
Example 11 (30 ° C.) Etching rate: 680 nm / min, residual film etching time: 9.7 seconds, total etching time: (90 + 9.7) × 1.2 = 119.6 seconds Example 12 (70 ° C. Etching rate: 725 nm / min, Residual film etching time: 9.2 seconds, Total etching time: (90 + 9.2) × 1.2 = 119.0 seconds Example 13 (100 ° C.) Etching rate: 730 nm / min Residual film etching time: 9.1 seconds, Total etching time: (90 + 9.1) × 1.2 = 119.0 seconds Example 14 (120 ° C.) Etching rate: 735 nm / min, Residual film etching time: 9 .1 second, total etching time: (90 + 9.1) × 1.2 = 119.0 seconds

(Examples 15 to 17)
Example 1 except that the over-etching rate was changed to 0%, 10%, and 30% among the etching conditions of (d) the first etching step and (e) the second etching step in Example 1. A monochromatic color filter was prepared in the same manner as described above.
The total etching time for each condition was as follows.
Example 15 (0%) Total etching time: 90 + 9.5 = 99.5 seconds Example 16 (10%) Total etching time: (90 + 9.5) × 1.1 = 109.5 seconds Example 17 (30%) Total etching time: (90 + 9.5) × 1.3 = 129.5 seconds

(Example 18)
In Example 8, after performing the second etching process and before the photoresist layer removing process, the third etching process and the fourth etching process were performed under the following conditions. A monochromatic color filter was produced.
(1) Third etching step RF power: 600 W, antenna bias: 100 W, wafer bias: 100 W, chamber internal pressure: 2.0 Pa, substrate temperature: 50 ° C., gas type and flow rate: oxygen gas: 25 mL / min, Ar gas: 250 mL / min (O ₂ / Ar = 1: 10), and the etching time was set to 20 seconds.
(2) Fourth etching step RF power: 300 W, antenna bias: 100 W, wafer bias: 100 W
The internal pressure of the chamber was 2.0 Pa, the substrate temperature was 50 ° C., the oxygen gas flow rate was 50 mL / min, and the treatment time was set to 5 seconds.

(Example 19)
In Example 18, a monochromatic color filter was produced in the same manner as in Example 18 except that the third etching step was changed to the following conditions.
(1) Third etching step RF power: 600 W, antenna bias: 100 W, wafer bias: 100 W
Internal pressure of the chamber: 4.0 Pa, substrate temperature: 50 ° C., gas type and flow rate: oxygen gas: 25 mL / min, Ar gas: 250 mL / min (O ₂ / Ar = 1: 10), and processing time is 20 seconds. Was set.

(Example 20)
In Example 8, a monochromatic color filter was produced in the same manner as in Example 8 except that the third etching process was performed under the following conditions after the second etching process and before the photoresist layer removing process. did.
(1) Third etching step RF power: 600 W, antenna bias: 100 W, wafer bias: 100 W, chamber internal pressure: 2.0 Pa, substrate temperature: 50 ° C., gas type and flow rate: oxygen gas: 25 mL / min, Ar gas: 250 mL / min (O ₂ / Ar = 1: 10), and the etching time was set to 20 seconds.

(Example 21)
In Example 8, a monochromatic color filter was produced in the same manner as in Example 8 except that the third etching process was performed under the following conditions after the second etching process and before the photoresist layer removing process. did.
(1) Third etching step RF power: 600 W, antenna bias: 100 W, wafer bias: 100 W, chamber internal pressure: 2.0 Pa, substrate temperature: 50 ° C., gas type and flow rate: oxygen gas: 50 mL / min, Ar gas: 250 mL / min (O ₂ / Ar = 1: 5), and the etching treatment time was set to 10 seconds.

(Example 22)
In Example 8, a monochromatic color filter was produced in the same manner as in Example 8 except that the third etching process was performed under the following conditions after the second etching process and before the photoresist layer removing process. did.
(1) Third etching step RF power: 600 W, antenna bias: 100 W, wafer bias: 100 W, chamber internal pressure: 2.0 Pa, substrate temperature: 30 ° C., gas type and flow rate: oxygen gas: 25 mL / min, Ar gas: 250 mL / min (O ₂ / Ar = 2: 5), and the etching time was set to 20 seconds.

(Example 23)
In Example 8, a monochromatic color filter was produced in the same manner as in Example 8 except that the third etching process was performed under the following conditions after the second etching process and before the photoresist layer removing process. did.
(1) Third etching step RF power: 600 W, antenna bias: 100 W, wafer bias: 100 W, chamber internal pressure: 4.0 Pa, substrate temperature: 50 ° C., gas type and flow rate: oxygen gas: 25 mL / min, Ar gas: 250 mL / min (O ₂ / Ar = 1: 10), and the etching time was set to 20 seconds.

(Example 24)
In Example 8, a monochromatic color filter was produced in the same manner as in Example 8 except that the third etching process was performed under the following conditions after the second etching process and before the photoresist layer removing process. did.
(1) Third etching step RF power: 600 W, antenna bias: 100 W, wafer bias: 100 W, chamber internal pressure: 2.0 Pa, substrate temperature: 50 ° C., gas type and flow rate: oxygen gas: 25 mL / min, Ar gas: 500 mL / min (O ₂ / Ar = 1: 20), and the etching time was set to 20 seconds.

(Comparative Example 1)
In the same manner as in Example 1, (a) colored layer forming step, (b) photoresist layer forming step, and (c) image forming step, a silicon wafer having a colored layer on which an image formed by a photoresist layer was formed. did. Next, (d) the first etching step and (e) the second etching step in Example 1 were not carried out, and the etching step was carried out under the following etching conditions. (F) Photoresist layer as in Example 1 Removal was performed to produce a single color filter.
-Etching conditions-
RF power: 800 W, antenna bias: 400 W, wafer bias: 200 W, chamber internal pressure: 4.0 Pa, substrate temperature: 50 ° C., mixed gas with dry etching apparatus (Hitachi High Technologies, U-621) The gas type and flow rate were set to CF ₄ : 80 mL / min. , O ₂ : 40 mL / min. , Ar: 800 mL / min. It was. The overetching rate was 20%.
It took about 110 seconds to etch (remove) the colored layer formed of SG-5000L under the above etching conditions to expose the support like a pattern. Since the overetching rate was 20%, the etching time was 110 seconds, the overetching time was 110 × 0.2 = 22 seconds, and the total etching time was set to 110 + 22 = 132 seconds.

(Comparative Example 2)
In Comparative Example 1, a monochromatic color filter was produced in the same manner as Comparative Example 1 except that the overetching treatment was not performed.

-Evaluation-
(Peelability)
For the color filters produced in Examples 1 to 4, Examples 6 to 24, Reference Example 5 and Comparative Examples 1 to 2, the surface of the colored layer was observed with a microscope (50,000 times magnification), scanning electron microscope (SEM) Evaluation was performed by observation of the surface of the colored layer and the side wall (magnification: 30,000). Evaluation was performed according to the following evaluation criteria. The evaluation results are shown in Table 1.
~Evaluation criteria~
○: No peeling residue of the photoresist was observed, and the peelability was very good.
Δ: Photoresist peeling residue was slightly observed, but was in a practically acceptable range.
X: The remaining peeling of the photoresist was seen on the entire surface, and the peelability was poor.

(Rectangularity)
The color filters produced in Examples 1 to 4, Examples 6 to 24, Reference Example 5 and Comparative Examples 1 and 2 were observed with a scanning electron microscope (SEM) (magnification: 100,000 times), and according to the following criteria. evaluated. The evaluation results are shown in Table 1.
~Evaluation criteria~
A: The cross section was a rectangle or a square with a right angle.
(Triangle | delta): The cross section was not a right angle | corner but a little roundness.
X: The cross section was tapered.

(Support damage)
The color filters produced in Examples 1 to 4, Examples 6 to 24, Reference Example 5 and Comparative Examples 1 and 2 were observed with a scanning electron microscope (SEM) (magnification: 20,000 times), and in accordance with the following criteria. evaluated. The evaluation results are shown in Table 1.
~Evaluation criteria~
○: There was no support damage.
Δ: Support damage is at an allowable level (there is a step, but the support scraping was 50 nm or less)
X: The support was scraped by 50 nm or more.

(Residue, etching residue)
The color filters produced in Examples 1 to 4, Examples 6 to 24, Reference Example 5 and Comparative Examples 1 and 2 were observed with a scanning electron microscope (SEM) (magnification: 20,000 times), and the residue and etching residue Evaluated. Evaluation was performed according to the following evaluation criteria. The evaluation results are shown in Table 1.
~Evaluation criteria~
A: There was no residue and no etching residue.
○: There was almost no residue or etching residue.
Δ: Residue and etching residue were partially generated in the wafer surface, but were at an acceptable level.
X: Residue and etching residue exceeded the allowable range for practical use.

(Side deposits)
The color filters produced in Examples 1 to 4, Examples 6 to 24, Reference Example 5 and Comparative Examples 1 and 2 were observed with a scanning electron microscope (SEM) (magnification: 20,000 times), and the side wall deposits were observed. The amount of adhesion was evaluated. Evaluation was performed according to the following evaluation criteria. The evaluation results are shown in Table 1.
~Evaluation criteria~
○: Side wall deposits were removed and there was no deposit at all.
Δ: There was a little side wall deposit, but it was an acceptable level.
X: A large amount of side wall deposits adhered.

From the results of Table 1 above, in the color filters of Examples 1 to 4 and 6 to 24 produced by the production method of the present invention, the support damage was not permissible or recognized. Moreover, the peelability of the photoresist layer was good, and no photoresist peeling residue was observed in the photoresist layer removal step. Furthermore, the rectangularity of the colored layer pattern was also good.
Further, in Examples 18 to 24 in which the third etching process was performed, the side wall deposits and the residue on the support were more effectively removed than in the case where the third etching process was not performed. It was. Furthermore, damage to the support accompanying the overetching treatment was also effectively suppressed.

It is sectional drawing which shows the state in which the colored layer was formed on the support body. It is sectional drawing which shows the state in which the photoresist layer was formed on the colored layer. It is sectional drawing which shows the state of the photoresist layer after exposure. It is sectional drawing which shows the state of the photoresist layer after image development processing. It is sectional drawing which shows the layer structure after a 1st etching process. It is sectional drawing which shows the layer structure after a 2nd etching process. It is sectional drawing which shows the layer structure after a photoresist layer removal.

Explanation of symbols

DESCRIPTION OF SYMBOLS 1 Support body 2 Colored layer 3 Photoresist layer 4 Uncured latent image area 5 Colored layer exposure part 6 Colored layer removal part 7 Support body exposure part

Claims (12)

(A) a colored layer forming step of forming a colored layer on the support;
(B) a photoresist layer forming step of forming a photoresist layer on the colored layer;
(C) an image forming step of forming an image on the colored layer by removing the photoresist layer in a pattern-like manner;
(D) 1st mixing which contains fluorine-type gas and oxygen gas, and the content ratio (fluorine-type gas / oxygen gas) of said fluorine-type gas and said oxygen gas is 2/1-8/1 by flow rate ratio A part of the colored layer is removed by dry etching using gas in a range where the support is not exposed, and the thickness of the colored layer is 10% to 20% like the pattern formed by the image forming process. A first etching step for forming a colored layer removal portion,
(E) After the first etching step, nitrogen gas and oxygen gas are included, and the content ratio of nitrogen gas and oxygen gas (nitrogen gas / oxygen gas) is 10/1 to 3/1 in flow rate ratio. A second etching step of removing at least a part of the colored layer removal portion by a dry etching method using a second mixed gas and forming a support exposed portion like the pattern;
(F) a photoresist layer removing step of removing the photoresist layer remaining after the second etching step;
Of manufacturing a color filter for a solid-state imaging device.   2. The method of manufacturing a color filter for a solid-state imaging device according to claim 1, wherein the second etching step uses the second mixed gas not containing a fluorine-based gas.   After the second etching step and before the photoresist layer removing step, the sidewall deposit generated in the second etching step is formed by a dry etching method using a third mixed gas containing oxygen gas. The method for manufacturing a color filter for a solid-state imaging device according to claim 1, further comprising a third etching step for removing the solid-state image sensor.   The third mixed gas is a mixed gas of oxygen gas and argon gas, and the content ratio of oxygen gas to argon gas (oxygen gas / argon gas) is 10/800 to 100/500 in flow rate ratio. The manufacturing method of the color filter for solid-state image sensors of Claim 3 characterized by the above-mentioned.   After the third etching step and before the photoresist layer removing step, a fourth etching for removing the altered layer derived from the sidewall deposit and the photoresist layer by a dry etching method using oxygen gas. The method for producing a color filter for a solid-state imaging device according to claim 3, further comprising a step.   6. The method for manufacturing a color filter for a solid-state imaging device according to claim 1, wherein the second etching step further includes an over-etching treatment step. The fluorine _gas, one of _{CF 4, C 4 F 8,} C 2 F 6 and claim 1 to claim 6, characterized in that at least one fluorine-based gas selected from the group consisting of CHF ₃ The manufacturing method of the color filter for solid-state image sensors of item 1. At least the first mixed gas is, Ar, He, Kr, further comprising at least one gas selected from the group consisting of _{N 2,} and Xe, Ar, He, Kr, selected from the group consisting of _{N 2,} and Xe The content of the one kind of gas in the first mixed gas is 25 or less in terms of a flow rate ratio when oxygen gas is set to 1, 8. The manufacturing method of the color filter for solid-state image sensors of description.   The second mixed gas further includes at least one gas selected from the group of Ar, He, Kr, and Xe, and the at least one gas selected from the group of Ar, He, Kr, and Xe 9. The solid-state imaging device according to claim 1, wherein the content in the second mixed gas is 25 or less in terms of a flow ratio when the oxygen gas is 1. A method for producing a color filter.   10. The manufacturing of a color filter for a solid-state imaging device according to claim 1, wherein in the first etching step, the internal pressure of the chamber is 2.0 to 6.0 Pa. 11. Method.   11. The manufacturing of a color filter for a solid-state imaging device according to claim 1, wherein in the second etching step, the internal pressure of the chamber is 1.0 to 4.0 Pa. Method.   The temperature of the said support body in a said 1st etching process and / or a said 2nd etching process is 30 to 100 degreeC, It is any one of Claims 1-11 characterized by the above-mentioned. Manufacturing method of color filter for solid-state image sensor.