JP2015173184A - Alkali etching mask agent composition, and etching method - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide: an alkali etching mask agent composition which enables the formation of an alkali etching mask superior in alkali resistance; and an alkali etching method arranged by use of such an alkali etching mask agent composition.SOLUTION: An alkali etching mask agent composition according to the present invention comprises polysiloxane having a structural unit expressed by the general formula (a1) below. The content of the structural unit expressed by the general formula (a1) is 15-100 mol% to all of structural units in the polysiloxane. In the formula, Rrepresents a single bond or an alkylene group with 1-5 carbon atoms; and Rrepresents an aryl group with 6-20 carbon atoms, which may have, as a substituent group, an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, an aryl group, a cyano group, or an amino group.

Description

  The present invention relates to an alkali etching mask agent composition and a method for alkaline etching of a silicon substrate using the same.

  In the manufacturing process of a semiconductor, particularly a solar cell, for example, a silicon substrate is partially selectively etched to texture the substrate surface to improve photoelectric conversion efficiency. As an etching process for such texture processing, there is a method using anisotropic etching using crystal orientation with an aqueous alkali solution such as sodium hydroxide or potassium hydroxide (hereinafter referred to as “alkali etching”).

  Conventionally, as a method of selectively performing alkali etching on a silicon substrate, an oxide film is formed on one surface of the substrate by thermal oxidation or CVD (chemical vapor deposition), and the oxide film is partially opened by photolithography. A method of selectively etching the portion after opening is common. For example, in Patent Document 1, an etching resistant film is formed on the surface of a substrate by thermal oxidation or CVD, a water repellent film guide is formed on the etching resistant film, and then a polyolefin mask pattern is formed. An alkaline etching is disclosed.

  However, such a conventional method results in an increase in the number of steps in the manufacturing process and involves a lot of capital investment, and thus has a very low productivity.

  A mask agent (etching mask agent) is used when performing partial selective etching on the substrate. For example, by using a printing type alkali etching mask, the problems associated with the above-described alkali etching treatment are improved. It is thought that it is possible.

  However, there is no known alkali etching mask agent that has excellent resistance (alkali resistance) to an alkaline aqueous solution that is an etching solution. Even if a mask agent is patterned on a silicon substrate, the mask agent is formed by alkali etching treatment. As a result, the etching of the silicon substrate under the masking agent progressed, and the desired pattern could not be effectively etched.

JP 2011-192921 A

  The present invention has been made in view of the above situation, and uses an alkali etching mask agent composition capable of forming an alkali etching mask having excellent alkali resistance, and the alkali etching mask agent composition. It is an object of the present invention to provide an alkaline etching method.

  As a result of intensive studies in order to solve the above-mentioned problems, the inventors of the present invention contain a polysiloxane having a specific structural unit, and the specific structural unit is predetermined with respect to all the structural units in the polysiloxane. It was found that the alkali resistance of the resulting mask was improved by using the alkali etching masking agent composition contained in the ratio, and the present invention was completed.

  1st aspect of this invention contains polysiloxane which has a structural unit represented by the following general formula (a1), and is represented by general formula (a1) with respect to all the structural units in the polysiloxane. It is an alkali etching mask agent composition whose content of a structural unit is 15-100 mol%.

（式中、Ｒ^１は単結合又は炭素数１〜５のアルキレン基であり、Ｒ^２は置換基としてアルキル基、アルコキシ基、ハロゲン原子、ハロゲン化アルキル基、アリール基、シアノ基、アミノ基を有していてもよい炭素数６〜２０のアリール基である。）

(In the formula, R ¹ represents a single bond or an alkylene group having 1 to 5 carbon atoms, and R ² represents an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, an aryl group, a cyano group or an amino group as a substituent. (It is an aryl group having 6 to 20 carbon atoms which may be present.)

  According to a second aspect of the present invention, there is provided a composition layer forming step of selectively forming a composition layer comprising the above-described alkali etching mask agent composition on a silicon substrate, and drying the composition layer to form a silicon substrate. An etching method for a silicon substrate, comprising: an alkali etching mask forming step for forming an alkali etching mask thereon; and an alkali etching step for treating the silicon substrate on which the alkali etching mask is formed with an alkali etching solution.

  According to the alkali etching mask agent composition of the present invention, an alkali etching mask having excellent alkali resistance can be formed. And the mask obtained using this alkali etching mask agent composition forms a pattern on a board | substrate, An etching process can be effectively given to the desired pattern with respect to the board | substrate.

It is a figure for demonstrating the flow of the process of an alkali etching method.

  Hereinafter, specific embodiments of the present invention will be described. In addition, this invention is not limited to the following embodiment, A various change is possible in the range which does not change the summary of this invention.

<< 1. Alkali Etching Mask Agent Composition >>
The alkali etching mask agent composition according to the present invention contains a polysiloxane having a structural unit represented by the following general formula (a1), and the following general formula (a1) with respect to all structural units in the polysiloxane. The content of the structural unit represented by is 15 to 100 mol%.

In the formula (a1), R ¹ is a single bond or an alkylene group having 1 to 5 carbon atoms, and R ² is an alkyl group, an alkoxy group, a halogen atom, a halogenated alkyl group, an aryl group, a cyano group as a substituent, And / or an aryl group having 6 to 20 carbon atoms which may have an amino group.

  According to such an alkali etching mask agent composition, an etching mask formed by printing using an ink made of this composition has excellent alkali resistance. Thereby, only the part other than the mask pattern can be effectively etched by performing an alkali etching process using the etching mask. Moreover, without increasing the number of manufacturing process steps and capital investment as in the conventional method of selectively etching an oxide film formed by thermal oxidation or CVD method by partially opening a window by photolithography method. An efficient alkali etching process can be performed on the silicon substrate.

  Here, in the alkali etching mask agent composition according to the present invention, it is preferable that the composition does not contain an inorganic filler such as silica. If an inorganic filler is present in the composition, the alkali resistance of the alkali etching mask formed by printing may not be sufficiently obtained. Although the viscosity of the ink made of the alkali etching mask agent composition can be increased by containing an inorganic filler, it can be easily increased by adding a thixotropic agent as required without containing the inorganic filler. The mask pattern can be formed by a suitable printing method.

<Polysiloxane>
As described above, the alkali etching mask agent composition according to the present invention contains polysiloxane having a structural unit represented by the general formula (a1).

In the general formula (a1), R ¹ is a single bond or an alkylene group having 1 to 5 carbon atoms, and R ¹ is preferably a single bond. Further, when R ¹ is an alkylene group, preferably an alkylene group having 1 to 4 carbon atoms. Specific examples in the case where R ¹ is an alkylene group include a methylene group, a 1,2-ethylene group, a 1,1-ethylene group, a propane-1,3-diyl group, and a propane-1,2-diyl group. Propane-1,1-diyl group, propane-2,2-diyl group, butane-1,4-diyl group, butane-1,3-diyl group, butane-1,2-diyl group, butane-1, Examples include 1-diyl group, butane-2,2-diyl group, butane-2,3-diyl group, pentane-1,5-diyl group, and pentane-1,4-diyl group.

In the general formula (a1), R ² is an aryl group having 6 to 20 carbon atoms which may have a substituent, and may have a substituent in that it can be synthesized at low cost. A good aryl group having 6 to 10 carbon atoms is preferred. In addition, examples of the substituent that the aryl group may have include alkyl groups such as methyl group, ethyl group, propyl group, and isopropyl group, alkoxy groups such as methoxy group, ethoxy group, propoxy group, and butoxy group, fluorine , Halogen atoms such as chlorine, iodine, bromine, etc., aryl groups such as halogenated alkyl groups, phenyl groups, naphthyl groups, etc. in which some or all of the hydrogen atoms of the above-mentioned alkyl groups such as fluorinated alkyl groups are substituted with halogen atoms , A cyano group, and / or an amino group. Specific examples of R ² include a phenyl group, an ethylphenyl group, a methoxyphenyl group, a naphthyl group, and a methylnaphthyl group.

  The polysiloxane contains the structural unit represented by the general formula (a1) at a ratio of 15 to 100 mol% with respect to all the structural units in the polysiloxane. Moreover, it is more preferable to contain the structural unit represented by the said general formula (a1) in the ratio of 40-100 mol%. When the content of the structural unit represented by the general formula (a1) is 15 to 100 mol%, the alkali resistance of the etching mask formed using the ink composed of the alkali etching mask agent composition according to the present invention is improved. Can be effectively increased.

  The mass average molecular weight (Mw) of the polysiloxane is not particularly limited as long as the effects of the present invention are not impaired, but for example, it is preferably 500 to 30000, more preferably 1000 to 10000. 1000 to 5000 is particularly preferable. In addition, in this specification, a mass average molecular weight (Mw) means the thing of standard polystyrene conversion measured by gel permeation chromatography (GPC).

  The polysiloxane is preferably a polysiloxane represented by the following general formula (a2).

In the formula (a2), R ¹ and R ² are as described above. R ³ is an alkyl group having 1 to 6 carbon atoms which may have a substituent. Substituents include alkyl groups such as methyl, ethyl, propyl and isopropyl groups, alkoxy groups such as methoxy, ethoxy, propoxy and butoxy, halogen atoms such as fluorine, chlorine, iodine and bromine, fluorine A halogenated alkyl group in which a part or all of the hydrogen atoms of the above-described alkyl group such as an alkylated alkyl group are substituted with a halogen atom; a cyano group; an amino group; a vinyl group, an allyl group, a butenyl group, an ethenyl group, a propynyl group, etc. An alkenyl group, an epoxy group, a glycidoxy group, an acryloyloxy group, and / or a methacryloyloxy group. Note that the subscripts p and q represent the mole percentage of structural units to which subscripts are attached to all the structural units in the polysiloxane, p is 15 to 100 mol%, and q is 0 to 85 mol%. , P and q are 100 mol%.

In the polysiloxane represented by the above formula (a2), each structural unit in the polysiloxane may have two or more different structural units of R ^{1 to} R ³ . When two or more structural units containing R ^{1 to} R ² are present, a combination of structural units in which R ¹ is a single bond and an alkylene group having 1 to 5 carbon atoms, or R ² is an unsubstituted aryl group and R ^2. The combination of the structural unit which becomes the aryl group which has the substituent mentioned above in is preferable. Also, if the structural units containing R ³ is 2 or more, R ³ is an alkyl group having 1 to 6 carbon atoms having a substituent described above in the alkyl group and R ³ having 1 to 6 carbon atoms unsubstituted Combinations of structural units are preferred.

  In the solid content of the alkali etching mask agent composition according to the present invention, the content ratio of the polysiloxane is not particularly limited, but is preferably a ratio of 85% by mass or more in the solid content. When the content of the polysiloxane in the solid content is 85% by mass or more, an etching mask having better alkali resistance can be formed, and the progress of etching to the silicon substrate under the mask agent is more effective. Can be prevented.

<Organic solvent>
The alkali etching mask agent composition according to the present invention is preferably used in the form of a solution (ink) by dissolving all the components such as the above-described polysiloxane and additives described later in an appropriate organic solvent. The organic solvent can be used singly or in combination of two or more.

  Specifically, examples of the organic solvent 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 -Ketones such as n-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, polyhydric alcohols or Monoalkyl ethers such as monomethyl ether, monoethyl ether, monopropyl ether, monobutyl ether of compounds having an ester bond Derivatives of polyhydric alcohols such as compounds having an ether bond such as ruthenium or monophenyl ether; cyclic ethers such as dioxane; methyl lactate, ethyl lactate, methyl acetate, ethyl acetate, butyl acetate, methyl pyruvate, ethyl pyruvate , Esters such as methyl methoxypropionate and ethyl ethoxypropionate; anisole, ethylbenzyl ether, cresyl methyl ether, diphenyl ether, dibenzyl ether, phenetole, butylphenyl ether, ethylbenzene, diethylbenzene, amylbenzene, isopropylbenzene, toluene, Aromatic organic solvents such as xylene, cymene, and mesitylene are listed. Among these, it is preferable to use diethylene glycol monoethyl ether acetate, propylene glycol monomethyl ether acetate (PGMEA), propylene glycol monomethyl ether (PGME), and n-butanol.

  The blending amount of the organic solvent is not particularly limited, but is preferably an amount such that the concentration of the polysiloxane described above is about 0.1 to 50% by mass, and is an amount that is about 1 to 40% by mass. More preferably, the amount is about 1 to 30% by mass.

<Other ingredients>
The alkali etching mask agent composition according to the present invention may contain other components in addition to the above-described polysiloxane and organic solvent, if necessary. Examples of other components include, but are not limited to, surfactants and thixotropic agents.

(Surfactant)
Specifically, the surfactant is not particularly limited, and a known one can be used. For example, a silicon-based, acrylic-based, or fluorine-based surfactant can be used. By adding such a surfactant, when an alkali etching mask composition (ink) was printed on a silicon substrate, the printed pattern width on the substrate was actually printed. It is possible to increase the printing stability by suppressing the occurrence of so-called printing bleeding, such as an increase in the width of the pattern.

  Examples of the silicone-based surfactant include SF8421EG (manufactured by Toray Dow Corning Co., Ltd.), BYK-310 (manufactured by BYK Chemie Co., Ltd.) mainly composed of polyester-modified polydimethylsiloxane, and aralkyl-modified polymethylalkylsiloxane. BYK-323 (manufactured by Big Chemie Co., Ltd.), BYK-SILCLEAN 3720 (manufactured by BYK Chemie Co., Ltd.), whose main component is a polyether-modified hydroxyl group-containing polydimethylsiloxane, and polyether-modified methylpolysiloxane as a main component. KF-353 (manufactured by Shin-Etsu Chemical Co., Ltd.) and the like. Examples of the acrylic surfactant include BYK-354 (manufactured by Big Chemie Co., Ltd.). Moreover, as a fluorine-type surfactant, KL-600 (made by Kyoeisha Chemical Co., Ltd.) etc. are mentioned, for example. Among these, it is preferable to add a silicon-based surfactant.

  Although it does not specifically limit as addition amount of surfactant, For example, it is preferable to set it as about 0.001-1.0 mass%, and it is more preferable to set it as about 0.01-0.3 mass%.

(Thixotropic agent)
The thixotropic agent can be added as a so-called rheology control agent, and can effectively increase the viscosity of the alkali etching mask agent composition and form a mask pattern by a method such as screen printing during pattern printing. In particular, in the alkali etching mask agent composition according to the present invention, it is preferable not to contain an inorganic filler as described above. Therefore, the viscosity of the composition is likely to be lowered by not containing an inorganic filler. At this time, by adding a thixotropic agent as an additive, the viscosity of the composition can be effectively increased, and a mask pattern can be formed by a suitable printing method such as screen printing.

  Specifically, the thixotropic agent is not particularly limited, and a known commercial product can be used. For example, BYK-405, BYK-410, BYK-430 (each manufactured by BYK Chemie Co., Ltd.) and the like are commercially available as thixotropic agents.

  As described above, the alkali etching mask agent composition according to the present invention contains the polysiloxane having the structural unit represented by the general formula (a1), and the above general formula for all structural units in the polysiloxane. Content of the structural unit represented by (a1) is 15-100 mol%. According to such an alkali etching mask agent composition, the resistance (alkali resistance) of an alkali etching mask formed by printing to an alkali etching solution can be extremely effectively improved. As a result, unlike the conventional method, an oxide film is formed by thermal oxidation, CVD, or the like, and a portion of the formed oxide film is selectively etched after opening a window by a photolithography method. An alkali etching process can be performed with high productivity while suppressing an increase in the number and capital investment.

≪2. Alkaline etching method >>
Next, an alkali etching method using the above-described alkali etching mask agent composition will be described. FIG. 1 is a schematic diagram for explaining the flow of steps of an alkali etching method according to the present invention.

  As shown in FIGS. 1A to 1C, the alkali etching method according to the present invention includes a composition layer forming step of selectively forming a composition layer on a silicon substrate, and drying the formed composition layer. And an alkali etching mask forming step for forming an alkali etching mask, and an alkali etching step for treating the silicon substrate with an alkali etching solution.

<Composition layer formation step>
In the composition layer forming step, the composition layer 20 is selectively formed on the silicon substrate 10 as shown in FIG. More specifically, in the alkali etching method according to the present invention, the polysiloxane having the structural unit represented by the general formula (a1) is contained, and the general formula (a1) with respect to all the structural units in the polysiloxane. An ink comprising an alkali etching mask agent composition having a content of a structural unit represented by 15 to 100 mol% is selectively printed on the silicon substrate 10 by pattern printing, and a layer comprising the composition ( A composition layer 20) is formed.

  The ink pattern printing method comprising the alkali etching mask agent composition described above is not particularly limited, and examples thereof include screen printing methods, ink jet printing methods, roll coat printing methods, letterpress printing methods, intaglio printing methods, and offsets. A mask pattern is formed using a printing method such as a printing method.

  Although it does not specifically limit as thickness (film thickness) of the composition layer 20 formed at a composition layer formation process, For example, it is preferable to set it as about 5-100 micrometers, and it is more preferable to set it as about 10-50 micrometers.

  In this composition layer forming step, various pretreatments may be performed on the silicon substrate 10 as necessary prior to forming the composition layer 20 on the silicon substrate 10. Examples of the pretreatment include a cleaning process for a silicon substrate and a liquid crystal layer forming process. With respect to the formation process of the lyophobic layer, for example, a method described in JP-A-2009-253145 may be mentioned.

<Alkali etching mask formation process>
Next, in the alkali etching mask forming step, as shown in FIG. 1B, the composition layer 20 formed selectively on the silicon substrate 10 is dried, and the alkali etching mask is formed on the silicon substrate 10. 20A (also simply referred to as “mask 20A”) is formed.

  The conditions for the drying (Bake) treatment of the composition layer 20 are not particularly limited, and can be appropriately set according to the film thickness of the composition layer 20, the components of the alkali etching mask agent composition, and the like. Specifically, for example, a drying process of about 3 minutes can be performed under a temperature condition of 150 to 200 ° C. By processing in this way, the solvent in the composition layer 20 formed on the silicon substrate 10 is dried, and the alkali etching mask 20A can be formed on the silicon substrate 10.

  Moreover, in this alkali etching mask formation process, after performing the drying process with respect to the composition layer 20, a baking (Cure) process can also be performed. The conditions for the baking treatment are not particularly limited, and can be appropriately set according to the film thickness of the composition layer 20, the components of the alkali etching mask agent composition, and the like. Specifically, for example, a baking process for about 15 minutes can be performed under a temperature condition of 250 to 400 ° C. In addition, when the temperature in a baking process is too high (for example, 600 degreeC or more), the organic group of the polysiloxane contained in the composition layer 20 will lose | disappear, and alkali tolerance with respect to the alkali etching liquid mentioned later may not fully be acquired. There is.

<Alkali etching process>
In the alkali etching step, as shown in FIG. 1C, the silicon substrate 10 on which the alkali etching mask 20A is formed is treated with an alkali etching solution. That is, an etching process is performed on portions other than the portion where the alkali etching mask 20A is formed on the silicon substrate 10.

The alkali etching solution (alkali etchant) used in the alkali etching step is not particularly limited, and a known one can be used. Specifically, for example, an etching solution having a composition of potassium hydroxide (KOH): 2% by mass, isopropyl alcohol (IPA): 8% by mass, water (H ₂ O): 90% by mass, potassium hydroxide (KOH) ): 10 wt%, water _(H 2 O): may be carried out using an etching solution or the like consisting of 90% by weight of the composition.

  Further, the alkali etching conditions are not particularly limited, and can be appropriately set according to a desired etching depth or the like with respect to the silicon substrate 10 other than the portion where the alkali etching mask 20A is formed. Specifically, for example, the temperature of the alkaline etching solution can be set to 80 ° C., and the silicon substrate 10 can be immersed in the alkaline etching solution for 1 to 30 minutes.

  In addition, after performing the alkali etching process as described above, the alkali etching mask 20A is removed. The removal method is not particularly limited. For example, using an organic solvent such as acetone or a commercially available stripping solution, the stripping method is performed by immersing the silicon substrate in the stripping solution at room temperature for about 5 to 10 minutes. Etc.

  As described above, the alkali etching mask 20A is formed on the silicon substrate 10, and the silicon substrate 10 on which the mask 20A is formed is subjected to the alkali etching process, so that only the portion where the mask 20A is not formed is selected. Can be etched. That is, in the alkali etching method according to the present invention, the mask 20A contains polysiloxane having a structural unit represented by the general formula (a1), and the general formula ( By forming with the ink which consists of an alkali etching mask agent composition whose content of the structural unit represented by a1) is 15-100 mol%, it can be set as the mask 20A which has the outstanding alkali tolerance. This effectively prevents the portion where the mask 20A is formed (under the mask agent) from being dissolved in the silicon substrate 10 by the alkaline etchant, and can effectively perform the etching process.

  EXAMPLES Hereinafter, although an Example is shown and this invention is demonstrated further in detail, this invention is not limited to these Examples.

≪Ink preparation, alkali etching mask formation, alkali etching treatment≫
[Example 1]
(Preparation of alkali etching mask agent composition)
As shown in the following Table 1, polysiloxane, an organic solvent, and additives as necessary were mixed to prepare an alkali etching mask agent composition. The numbers in parentheses “()” shown in the component indications in Table 1 indicate the content (blending amount) in the composition.

  Specifically, it is a polysiloxane (hereinafter referred to as “(A) -3”) containing a structural unit represented by the following formula (a3) in a proportion of 100 mol%, and has a mass average molecular weight Mw of 500 to 500. 40% by mass of 1500, 54.7% by mass of diethylene glycol monoethyl ether acetate (hereinafter referred to as “(S) -1”), and surfactant (product name: SF8421EG, Toray) as additive (1) -Dow Corning Co., Ltd. (hereinafter referred to as “SF8421EG”) is 0.3 mass%, and the thixotropic agent (product name: BYK-430, manufactured by BYK Chemie) (hereinafter “ BYK430 ”) was prepared, and an ink comprising an alkali etching masking agent composition containing 5% by mass was prepared.

(Formation of etching mask)
The ink prepared as described above was screen-printed on a silicon substrate using a 500 μm line pattern plate. Screen printing was performed at a temperature of 25 ° C. under the conditions of 300 mm / s and emulsion thickness of 10 μm.

  Subsequently, the solvent was baked on a 200 ° C. hot plate for 3 minutes. Thereafter, a baking process (Cure) was performed at 400 ° C. for 15 minutes to form an alkali etching mask on the silicon substrate.

(Alkaline etching treatment)
The baking treatment substrate (silicon substrate) on which the alkali etching mask was formed as described above was 80% with respect to the alkali etching solution (KOH: 2% by mass, IPA: 8% by mass, H ₂ O: 90% by mass). An alkali etching treatment was performed by immersing the substrate under etching conditions of -30 ° C.

[Example 2]
In Example 2, except that the content of polysiloxane ((A) -3) was 30% by mass and the content of diethylene glycol monoethyl ether acetate ((S) -1) was 64.7% by mass, An ink comprising an alkali etching mask agent composition was prepared in the same manner as in Example 1, and an etching mask was formed.

[Example 3]
In Example 3, the content of polysiloxane ((A) -3) was 20 mass%, the content of diethylene glycol monoethyl ether acetate ((S) -1) was 74.7 mass%, and the additive (2 The ink comprising the alkali etching mask agent composition was prepared in the same manner as in Example 1 except that the thixotropic agent (1) was not added.

  In Example 3, a mask pattern was printed on a silicon substrate by the ink jet printing method using the ink thus prepared.

[Example 4]
In Example 4, Example 1 was performed except that, when an etching mask was formed, an alkali etching mask was formed on a silicon substrate by performing a baking process (Cure) at 250 ° C. for 15 minutes after a drying (Bake) process. And the same.

[Example 5]
In Example 5, polysiloxane ((A) -3) containing the structural unit represented by the above formula (a3) at a ratio of 100 mol% and having a mass average molecular weight Mw of 30000 (note that In Table 1, “(A) -3 [Mw: 30000]”) is 40% by mass, diethylene glycol monoethyl ether acetate ((S) -1) is 54.9% by mass, and additive (1). An ink comprising an alkali etching mask agent composition containing 0.1% by mass of the surfactant (SF8421EG) and 5% by mass of the thixotropic agent (BYK430) of the additive (2) was prepared. Using this ink, pattern printing was performed by screen printing in the same manner as in Example 1 to form an etching mask, and alkaline etching treatment was performed.

[Example 6]
In Example 6, 40 masses of polysiloxane (Mw: 2000 to 4000) (hereinafter referred to as “(A) -4”) containing a structural unit represented by the following formula (a4) at a ratio of 100 mol%. %, 54.9% by mass of diethylene glycol monoethyl ether acetate ((S) -1), 0.1% by mass of surfactant (SF8421EG) of additive (1), thixotropic agent (BYK430) of additive (2) ) Was prepared from an alkali etching mask agent composition containing 5% by mass. Using this ink, pattern printing was performed by screen printing in the same manner as in Example 1 to form an etching mask, and alkaline etching treatment was performed.

[Example 7]
In Example 7, 40% by mass of polysiloxane (Mw: 4500) represented by the following formula (a5) (hereinafter referred to as “(A) -5”), diethylene glycol monoethyl ether acetate ((S) -1 Etching mask containing 54.9% by mass of surfactant (SF8421EG) of additive (1) and 5% by mass of thixotropic agent (BYK430) of additive (2) An ink comprising the agent composition was prepared. Using this ink, pattern printing was performed by screen printing in the same manner as in Example 1 to form an etching mask, and alkaline etching treatment was performed.

[Example 8]
In Example 8, 40% by mass of polysiloxane ((A) -3), 54.7% by mass of diethylene glycol monoethyl ether acetate ((S) -1), and surfactant (product name) as additive (1) : KL401, manufactured by Kyoeisha Chemical Co., Ltd. (hereinafter referred to as “KL401”) 0.3% by mass and an additive (2) thixotropic agent (BYK430) in a proportion of 5% by mass An ink comprising the composition was prepared.

Using this ink, after performing pattern printing by screen printing in the same manner as in Example 1, in Example 8, the substrate was subjected to alkaline etching treatment (KOH: 10% by mass, H ₂ O: 90) during the alkali etching treatment. (Mass%) was immersed in etching conditions at 80 ° C. for 5 minutes to perform alkali etching treatment.

[Example 9]
In Example 9, 30% by mass of polysiloxane ((A) -3), 64.7% by mass of diethylene glycol monoethyl ether acetate ((S) -1), and surfactant (SF8421EG) of additive (1) Was prepared from an alkaline etching masking agent composition containing 0.3% by mass of a thixotropic agent (BYK430) of additive (2) at a rate of 5% by mass.

  In Example 9, after using this ink to form a pattern on a silicon substrate by screen printing and drying (Bake), an alkali etching mask is formed on the silicon substrate without performing a baking process (Cure). Then, alkali etching treatment was performed. The drying process and the like and the etching process after the mask formation were performed under the same conditions as in Example 1.

[Examples 10 to 15]
In Examples 10 to 15, polysiloxane (Mw: 2500) represented by the following general formula (a6) and propylene glycol monomethyl ether acetate (PGMEA) as an organic solvent were mixed at a mass ratio of 10:90. Thus, an ink comprising an alkali etching mask agent composition was prepared.

（なお、上記一般式（ａ６）中の添え字ｐ１、ｑ１、及びｒ１は、ポリシロキサン中の全構造単位に対する添え字が付された構造単位のモル百分率を表す。）

(Note that the subscripts p1, q1, and r1 in the general formula (a6) represent the mole percentage of the structural unit to which the subscript is attached to all the structural units in the polysiloxane.)

Specifically, in Examples 10 to 15, the following were contained as polysiloxanes represented by the general formula (a6). That is,
Example 10 Polysiloxane [A] (in the above formula, p1: 59, q1: 1, r1: 40)
Example 11 Polysiloxane [B] (in the above formula, p1: 19, q1: 1, r1: 80)
Example 12 Polysiloxane [C] (in the above formula, p1: 39, q1: 1, r1: 60)
Example 13 Polysiloxane [D] (in the above formula, p1: 69, q1: 1, r1: 30)
Example 14 Polysiloxane [E] (in the above formula, p1: 79, q1: 1, r1: 20)
Example 15 Polysiloxane [F] (in the above formula, p1: 84, q1: 1, r1: 15)

  Using the ink thus prepared, pattern printing was performed by screen printing in the same manner as in Example 1 to form an etching mask, and alkaline etching treatment was performed.

[Comparative Example 1]
In Comparative Example 1, polysiloxane (Mw: 2400) represented by the following formula (b1) (hereinafter referred to as “(B) -1”) is 40% by mass, diethylene glycol monoethyl ether acetate ((S) -1 Etching mask containing 54.7% by weight of surfactant (0.3) by weight of additive (1) (SF8421EG) and 5% by weight of thixotropic agent (BYK430) of additive (2) An ink comprising the agent composition was prepared.

  Using this ink, a pattern is formed on a silicon substrate by screen printing and dried (Bake), and then an alkali etching mask is formed on the silicon substrate without performing a baking process (Cure), and an alkali etching process is performed. Was given. The drying process and the like and the etching process after the mask formation were performed under the same conditions as in Example 1.

[Comparative Example 2]
In Comparative Example 2, polysiloxane (Mw: 2000) represented by the following formula (b2) (hereinafter referred to as “(B) -2”) was 40% by mass, diethylene glycol monoethyl ether acetate ((S) -1 Etching mask containing 54.7% by weight of surfactant (0.3) by weight of additive (1) (SF8421EG) and 5% by weight of thixotropic agent (BYK430) of additive (2) An ink comprising the agent composition was prepared.

  Using this ink, a pattern is formed on a silicon substrate by screen printing and dried (Bake), and then an alkali etching mask is formed on the silicon substrate without performing a baking process (Cure), and an alkali etching process is performed. Was given. The drying process and the like and the etching process after the mask formation were performed under the same conditions as in Example 1.

[Comparative Example 3]
In Comparative Example 3, polysiloxane (Mw: 7000) represented by the following formula (b3) (hereinafter referred to as “(B) -3”) was 40% by mass, diethylene glycol monoethyl ether acetate ((S) -1 Etching mask containing 54.7% by weight of surfactant (0.3) by weight of additive (1) (SF8421EG) and 5% by weight of thixotropic agent (BYK430) of additive (2) An ink comprising the agent composition was prepared.

  Using this ink, a pattern is formed on a silicon substrate by screen printing and dried (Bake), and then an alkali etching mask is formed on the silicon substrate without performing a baking process (Cure), and an alkali etching process is performed. Was given. The drying process and the like and the etching process after the mask formation were performed under the same conditions as in Example 1.

[Comparative Example 4]
In Comparative Example 4, an ink composed of the same alkali etching mask agent composition as in Comparative Example 3 was prepared, and an etching mask was formed using the ink. After drying (Bake), the ink was subjected to 400 ° C. for 15 minutes. A baking process (Cure) was performed to form an alkali etching mask on the silicon substrate. The other conditions were the same as in Comparative Example 3.

[Comparative Examples 5 and 6]
In Comparative Examples 5 and 6, polysiloxane (Mw: 2500) represented by the above general formula (a6) and propylene glycol monomethyl ether acetate (PGMEA) as an organic solvent were mixed at a mass ratio of 10:90. Thus, an ink comprising an alkali etching mask agent composition was prepared.

Specifically, in Comparative Examples 5 and 6, the following were contained as polysiloxanes represented by the general formula (a6). That is,
Comparative Example 5 Polysiloxane [G] (in the above formula, p1: 90, q1: 10, r1: 0)
Comparative Example 6 Polysiloxane [H] (wherein p1: 89, q1: 1, r1: 10)

  Using the ink thus prepared, pattern printing was performed by screen printing in the same manner as in Example 1 to form an etching mask, and alkaline etching treatment was performed.

≪Evaluation of alkali resistance of etching mask≫
As described above, with respect to the substrate subjected to the alkali etching treatment in each example and comparative example, the presence or absence of the printing pattern (masking agent) and the presence or absence of the Si etching under the printing pattern (under the masking agent) are confirmed and etched. The alkali etching resistance of the mask was evaluated. Specifically, the alkali etching resistance was classified and evaluated as follows. Table 1 below shows the evaluation results of each example and comparative example.
“◯”: There was a print pattern, and Si etching under the print pattern did not progress.
“×”: The print pattern was dissolved at least partially and disappeared, and there was progress of Si etching under the print pattern.

  As shown in Table 1, it is a composition containing a polysiloxane having a structural unit represented by the general formula (a1), and is represented by the general formula (a1) with respect to all structural units in the polysiloxane. In Examples 1 to 15 in which an alkali etching mask was formed on a silicon substrate using an alkali etching mask composition having a content of a structural unit represented by 15 to 100 mol%, the alkali etching treatment was excellent. Alkali resistance was exhibited, and no etching progressed under the masking agent.

  In contrast, Comparative Examples 1 to 4 using a composition containing a polysiloxane having no structural unit represented by the general formula (a1), and a structure represented by the general formula (a1) In Comparative Examples 5 and 6 using a composition containing a polysiloxane having a unit, but the content of the structural unit of the general formula (a1) is less than 15 mol% with respect to all the structural units in the polysiloxane In contrast to the alkali etching treatment, Si etching under the masking agent has progressed. That is, it is considered that a part of the mask was dissolved because the alkali resistance of the formed alkali etching mask was weak, and as a result, the Si etching under the masking agent proceeded.

10 Silicon substrate 20 Composition layer 20A Alkaline etching mask

Claims (3)

A polysiloxane having a structural unit represented by the following general formula (a1) is contained, and the content of the structural unit represented by the following general formula (a1) is 15 to 15 with respect to all the structural units in the polysiloxane. An alkali etching mask composition which is 100 mol%.

(In the formula, R ¹ is a single bond or an alkylene group having 1 to 5 carbon atoms, and R ² is an alkyl group, alkoxy group, halogen atom, halogenated alkyl group, aryl group, cyano group, and / or as a substituent. (It is an aryl group having 6 to 20 carbon atoms which may have an amino group.) The alkali etching mask agent composition according to claim 1, wherein the polysiloxane is a polysiloxane represented by the following general formula (a2).

Wherein R ¹ and R ² are as defined above, and R ³ is an alkyl group, alkoxy group, halogen atom, halogenated alkyl group, cyano group, amino group, alkenyl group, epoxy group, glycidoxy group as a substituent. , An acryloyloxy group, and / or a methacryloyloxy group, and an alkyl group having 1 to 6 carbon atoms, and the subscripts p and q are attached to the subscripts for all structural units in the polysiloxane. The percentage of structural units formed, p is 15-100 mol%, q is 0-85 mol%, provided that the sum of p and q is 100 mol%.) A composition layer forming step of selectively forming a composition layer comprising the alkaline etching mask agent composition according to claim 1 or 2 on a silicon substrate;
An alkali etching mask forming step of drying the composition layer to form an alkali etching mask on the silicon substrate;
And an alkali etching step of treating the silicon substrate on which the alkali etching mask is formed with an alkali etching solution.

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