JP2008031370A - Flattened film-forming composition - Google Patents

Abstract

<P>PROBLEM TO BE SOLVED: To provide a flattened film-forming composition suppressing generation of striation of a film surface and forming a flattened film with excellent flatness in a coating by spin coating without using a surfactant. <P>SOLUTION: In the flattened film-forming composition containing a resin component and a solvent, the solvent is at least one kind of solvent selected from 3-methoxybutyl acetate and 3-methoxy-1-butanol. Further, the resin component is preferably an acrylic-based resin. <P>COPYRIGHT: (C)2008,JPO&INPIT

Description

  The present invention relates to a composition for planarization film formation. In particular, the present invention relates to a planarization film forming composition for forming a planarization film used for a CCD color filter, a CMOS color filter, and the like.

  In recent years, image-related photographing devices and display devices have been spreading at a remarkable pace, and these devices are required to have higher functions. In these devices, for example, various display devices such as a color liquid crystal display device (LCD), imaging devices such as a charge coupled device image sensor (CCD) and a complementary metal oxide semiconductor image sensor (CMOS), in most cases, The color filter is an essential component.

  In general, the color filter uses the red (R), green (G), and blue (B) colored layers, and a planarizing film is formed to cover and protect the colored layers. The planarizing film is required to have excellent transparency and excellent flatness so as not to adversely affect the sufficient hardness and adhesion and the color of the pixel.

This flattened film is formed by applying a composition dissolved in a solvent by spin coating, but there is a problem that striation occurs on the film surface and the flatness is poor. Therefore, a composition to which a surfactant is added to improve flatness is used (see Patent Document 1).
JP 2000-344866 A

  However, when a planarization film is formed using a composition containing a surfactant, there is a problem that foreign matter is generated due to a change with time, and the color of the pixel is adversely affected.

  The present invention has been made in view of the problems as described above. In the application by spin coating without using a surfactant, the occurrence of striations on the film surface is suppressed, and the flatness is excellent. It aims at providing the composition for planarization film formation which can form a chemical film.

  As a result of intensive studies to solve the above problems, the present inventors have found that the above problems can be solved by using a specific solvent for the composition for forming a planarizing film, and the present invention is completed. It came to. More specifically, the present invention provides the following.

  The present invention is a planarization film-forming composition comprising a resin component and a solvent, wherein the solvent comprises at least one solvent selected from 3-methoxybutyl acetate and 3-methoxy-1-butanol. A composition for forming a planarizing film.

  The composition for forming a flattened film of the present invention includes at least one selected from 3-methoxybutyl acetate and 3-methoxy-1-butanol as a solvent, so that the film does not contain a surfactant. Generation of surface striation can be suppressed. In particular, the use of an acrylic resin as the resin can effectively suppress the occurrence of striation.

<Composition for planarization film formation>
The planarization film-forming composition of the present invention contains a resin component and a solvent, and the solvent contains at least one solvent selected from 3-methoxybutyl acetate and 3-methoxy-1-butanol. Hereinafter, each component will be described.

[solvent]
The solvent contained in the composition for forming a planarizing film is at least selected from 3-methoxybutyl acetate (hereinafter also referred to as “MA”) and 3-methoxy-1-butanol (hereinafter also referred to as “MB”). Contains one species. By using this solvent, the occurrence of striation on the film surface can be suppressed.

In addition, other solvents can be added as long as the effects of the present invention are not impaired. Examples of other solvents include alcohols such as methanol, ethanol, propanol, and n-butanol; polyhydric alcohols such as ethylene glycol, diethylene glycol, propylene glycol, and dipropylene glycol; acetone, methyl ethyl ketone, cyclohexanone, and methyl-n- Ketones such as amyl ketone, methyl isoamyl ketone, 2-heptanone; compounds having an ester bond such as ethylene glycol monoacetate, diethylene glycol monoacetate, propylene glycol monoacetate, dipropylene glycol monoacetate, the polyhydric alcohols or the esters Monoalkyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether of compounds having a bond Derivatives of polyhydric alcohols such as compounds having an ether bond such as ter or monophenyl ether; cyclic ethers such as dioxane, methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, Esters such as ethyl pyruvate, methyl methoxypropionate, ethyl ethoxypropionate; anisole, ethyl benzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetole, butyl phenyl ether, ethyl benzene, diethyl benzene, amyl benzene, isopropyl benzene And aromatic organic solvents such as toluene, xylene, cymene and mesitylene.
When these other solvents are added, the total amount of 3-methoxybutyl acetate and 3-methoxy-1-butanol is preferably 50% by mass or more, more preferably 80% by mass with respect to the whole solvent. That's it.
In particular, the solvent is preferably only at least one of 3-methoxybutyl acetate and 3-methoxy-1-butanol.

  Although the usage-amount of a solvent will not be specifically limited if the composition for planarization film formation can be apply | coated uniformly, The density | concentration of solid content is 10-50 mass%, Preferably it is 15-35 mass%. It is preferable to adjust within the range.

[Resin component]
Although it does not specifically limit as a resin component contained in the composition for planarization film formation, Acrylic resin is preferable. By combining the acrylic resin and the solvent in the present invention, generation of striation can be effectively prevented.

  The acrylic resin preferably contains a copolymer (A) containing the structural unit (a) shown below and at least one selected from the structural unit (b) and the structural unit (c). .

（Ｒ^１、Ｒ^２、Ｒ^３は水素、または炭素数１から５のアルキル基を示し、ｍ、ｎは１から８の整数を示す。）

(R ¹ , R ² and R ³ represent hydrogen or an alkyl group having 1 to 5 carbon atoms, and m and n represent an integer of 1 to 8)

  Here, examples of the alkyl group having 1 to 5 carbon atoms include linear and branched alkyl groups. Examples of the linear or branched alkyl group include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, and a tert-butyl group.

  By using the resin component containing the structural unit (a), it is possible to suppress the occurrence of striation and form a flattened film with excellent flatness. Moreover, the hardness of the film | membrane after thermosetting can be improved by containing the structural unit (b) or (c) which has an epoxy group.

  Furthermore, it is preferable to contain the copolymer (B) containing the said structural unit (a) and the structural unit (d) represented by a following formula. By containing the structural unit (d), the etching resistance of the planarization film can be improved. Further, the dry etching rate can be adjusted by adjusting the content of the structural unit (d).

（Ｒ^４は水素または炭素数１から５のアルキル基、Ｒ^５は、水素、水酸基、または炭素数１から５のアルキル基を示す。）
ここで、炭素数１から５のアルキル基としては、直鎖状、分岐状のアルキル基を挙げることができる。直鎖状、分岐状のアルキル基としては、メチル基、エチル基、ｎ−プロピル基、ｉ−プロピル基、ｎ−ブチル基、ｔｅｒｔ−ブチル基などを挙げることができる。

(R ⁴ represents hydrogen or an alkyl group having 1 to 5 carbon atoms, and R ⁵ represents hydrogen, a hydroxyl group, or an alkyl group having 1 to 5 carbon atoms.)
Here, examples of the alkyl group having 1 to 5 carbon atoms include linear and branched alkyl groups. Examples of the linear or branched alkyl group include a methyl group, an ethyl group, an n-propyl group, an i-propyl group, an n-butyl group, and a tert-butyl group.

  The content of the structural unit (a) is preferably 30 to 90 mol%, more preferably 40 to 80 mol%, of all the structural units in the resin component.

  Further, the total content of the structural units (b) and (c) is preferably 10 mol% or more, more preferably 20 mol% or more, of all the structural units in the resin component.

  Moreover, it is preferable that content of a structural unit (d) is 10-80 mol% among all the structural units in a resin component.

  When the resin component contains the copolymer (A) and the copolymer (B), the mass ratio of the copolymer (A) and the copolymer (B) is (A) :( B) = 90: 10. It is preferably ~ 100: 0.

  The resin component contains a copolymer (C) containing the structural unit (a), at least one selected from the structural unit (b) and the structural unit (c), and the structural unit (d). May be. The content ratio of each structural unit in the copolymer (C) is such that the total amount of (b) and (c) is 10 mol% or more in the total structural units of the copolymer (C), and the structural unit (a): (D) = 10: 90 to 100: 0 (molar ratio) is preferable.

  The molecular weight of each component in the resin component is preferably 2000 to 15000, respectively. By making molecular weight into the said range, it becomes possible to make the solubility to a solvent favorable, and applicability | paintability can be improved. Further, the flatness of the formed flattening film can be further improved.

<Method for forming planarization film>
A method for forming a flattened film using the flattened film forming composition of the present invention will be described.
The flattened film forming composition of the present invention is applied to a substrate on which wiring, black matrix, color filters and the like are formed using a roll coater, spin coater, rotary cup coater, non-spin coater, or the like.

  After applying this flattening film-forming composition, it is dried to remove the solvent. The drying method is not particularly limited, and (1) a method of drying on a hot plate, (2) a method of leaving at room temperature for several hours to several days, (3) several tens to several tens of minutes in a warm air heater or an infrared heater Any method of removing the solvent with time may be used.

  Next, the planarization film-forming composition can be fired to obtain a planarization film. The baking method is not particularly limited, and for example, a method of baking on a hot plate can be used.

  Examples of the present invention will be described below. However, these examples are merely examples for suitably explaining the present invention, and do not limit the present invention.

（構成単位（ａ１）：構成単位（ｃ１）＝２５：７５（モル比）、分子量：１００００）２５ｇをＭＡ７５ｇに溶解し、２５％樹脂溶液（Ａ）を得た。
下記構成単位を有する共重合体（Ｂ）

（構成単位（ａ１）：構成単位（ｄ１）＝２５：７５（モル比）、分子量：８０００）２５ｇをＭＡ７５ｇに溶解し、２５％樹脂溶液（Ｂ）を得た。
樹脂溶液（Ａ）５０ｇ、樹脂溶液（Ｂ）５０ｇを混合し組成物を得た。 (Example 1)
Copolymer (A) having the following structural units

(Constitutional unit (a1): constitutional unit (c1) = 25: 75 (molar ratio), molecular weight: 10,000) 25 g was dissolved in 75 g of MA to obtain a 25% resin solution (A).
Copolymer (B) having the following structural units

(Constituent unit (a1): constituent unit (d1) = 25: 75 (molar ratio), molecular weight: 8000) 25 g was dissolved in 75 g of MA to obtain a 25% resin solution (B).
50 g of the resin solution (A) and 50 g of the resin solution (B) were mixed to obtain a composition.

(Comparative Example 1)
In Example 1, a composition was obtained in the same manner as in Example 1 except that 0.017 g of XR-104 (Dainippon Ink Co., Ltd.) was added as a surfactant.

(Comparative Example 2)
In Example 1, a composition was obtained in the same manner as in Example 1 except that 0.017 g of X-70-093 (manufactured by Shin-Etsu Chemical Co., Ltd.) was added as a surfactant.

(Comparative Example 3)
25 g of copolymer (A) was dissolved in 75 g of propylene glycol monomethyl ether to obtain a 25% resin solution (C).
25 g of copolymer (B) was dissolved in 75 g of propylene glycol monomethyl ether to obtain a 25% resin solution (D).
50 g of the resin solution (C) and 50 g of the resin solution (D) were mixed to obtain a composition.

[Formation of planarization film]
The compositions of Example 1 and Comparative Examples 1 to 3 were applied to an 8-inch wafer by spin coating. Drying was performed on a hot plate at 90 ° C. for 120 seconds. Then, it baked for 10 minutes at 200 degreeC with the hotplate, and formed the planarization film | membrane. It adjusted so that the film thickness after baking might be set to about 1.4 micrometers.

[Evaluation]
The striation on the flattened film surface was confirmed under a sodium lamp.
In addition, with an optical film thickness meter (SCANNING UV 210 (product name): manufactured by NANOMETRICS), flatness passes through the center of the wafer every 8 mm from the position 12 mm inside from the edge of the wafer, and the edge of the opposite wafer It was evaluated by measuring the film thickness at 23 points. The results are shown in Table 1.
The film thickness variation is
[{(Maximum value−minimum value) / 2} / average value] × 100
Determined by

From the results shown in Table 1, the flattened film-forming composition of Example 1 showed high flatness and no occurrence of striations. Compared with Comparative Examples 1 and 2 to which a surfactant was added, an equivalent quality product could be obtained. Moreover, the comparative example 3 which changed the solvent had bad flatness.

Claims (9)

A composition for forming a flattened film comprising a resin component and a solvent,
The composition for forming a planarizing film, wherein the solvent contains at least one solvent selected from 3-methoxybutyl acetate and 3-methoxy-1-butanol.   The planarization film-forming composition according to claim 1, wherein the resin component is an acrylic resin. The flat resin according to claim 2, wherein the acrylic resin contains a copolymer (A) containing the structural unit (a) and at least one selected from the structural unit (b) and the structural unit (c). Composition for forming a chemical film.

(R ¹ , R ² and R ³ represent hydrogen or an alkyl group having 1 to 5 carbon atoms, and m and n represent an integer of 1 to 8) The said acrylic resin contains the copolymer (B) containing the said structural unit (a) and the structural unit represented by following formula (d), The composition for planarization film formation of Claim 3 .

(R ⁴ represents hydrogen or an alkyl group having 1 to 5 carbon atoms, and R ⁵ represents hydrogen, a hydroxyl group, or an alkyl group having 1 to 5 carbon atoms.)   5. The composition for forming a planarizing film according to claim 3, wherein the content of the structural unit (a) is 30 mol% or more of all structural units in the resin component.   6. The planarization film-forming composition according to claim 3, wherein the total content of the structural unit (b) and the structural unit (c) is 10 mol% or more of all the structural units in the resin component. object.   The composition for forming a flattened film according to any one of claims 4 to 6, wherein a mass ratio of the copolymer (A) to the copolymer (B) is 90:10 to 100: 0.   The acrylic resin is a copolymer comprising the structural unit (a), at least one selected from the structural unit (b) and the structural unit (c), and the structural unit (d) ( The composition for planarization film formation in any one of Claim 4 to 7 containing C). The composition for forming a planarizing film according to any one of claims 1 to 8, wherein the molecular weight of each component in the resin component is 2000 to 15000, respectively.