JP4512092B2 - Thinner composition for removing photosensitive resin - Google Patents

Description

  The present invention relates to a thinner composition for removing a photoresist, and more particularly to a thinner composition capable of effectively removing a photoresist unnecessary in a manufacturing process of a semiconductor device or a liquid crystal display device.

  During the TFT-LCD manufacturing process, the TFT-array process is similar to the silicon semiconductor manufacturing process using photolithography. The photolithography process is a process in which a photosensitive film is applied to a substrate, a photomask pattern is transferred and developed, and an electronic circuit is formed by an etching process.

  A TFT-array is formed on a substrate for manufacturing a TFT-LCD through a photolithography process. Due to the phenomenon of penetration into the photoresist interface by the thinner composition in such a process, defects may occur in subsequent processes such as etching and ion implantation, resulting in a decrease in productivity in all processes. .

  Such a permeation phenomenon into the photoresist interface causes defocusing at the time of exposure after passing through the baking process, and decreases the productivity of the TFT-LCD manufacturing process.

  Unlike the edge part of the silicon wafer on which the centrifugal force acts, the TFT-LCD glass substrate is square, so that rotating EBR (edge bead removing) work is impossible. In addition, since the glass substrate is fixed and the spray nozzle moves linearly along the four surfaces of the glass substrate, the photoresist does not evaporate rapidly. Penetration into the interface occurs at the edge of the surface. This is different from rotating EBR in which the silicon wafer rotates at high speed and the penetration phenomenon from the edge of the photoresist into the interface is reduced even if the volatilization is slow. In other words, since the LCD glass substrate is fixed and only the thinner injection port moves, if a conventional highly soluble thinner is used, a penetration phenomenon to the photoresist interface occurs when rinsing the edge part, Reduce productivity.

  Next, a conventional thinner composition will be described.

  Japanese Unexamined Patent Publication No. 63-69563 discloses a method for removing unnecessary photoresist by bringing a thinner into contact with a substrate. Examples of organic solvents for cleaning removal include cellosolve, cellosolve acetate, propylene glycol. Ethers and ether acetates such as ether and propylene glycol ether acetate; ketones such as acetone, methyl ethyl ketone, methyl isobutyl ketone and cyclohexanone; esters such as methyl lactic acid, ethyl lactate, methyl acetate, ethyl acetate and butyl acetate are used as thinners To do. Japanese Unexamined Patent Publication No. 4-49938 discloses the use of propylene glycol methyl ether acetate as a thinner, and Japanese Unexamined Patent Publication No. 4-42523 discloses a method of using an alkylalkoxypropionate as a thinner. ing.

  That is, these solvents may be used alone or mixed for reasons of physical properties and safety. Unlike TFT-LCD processes where the substrate is fixed and linear EBR is performed, these solvents have also been used in the rotating EBR process at high rotational speeds.

  However, the conventional method cannot solve the problem of the penetration phenomenon into the photoresist interface.

  The present invention suppresses the interfacial penetration phenomenon with respect to the photoresist in the edge portion of the substrate used for manufacturing the liquid crystal display element, particularly a large glass substrate for an organic EL display element, and efficiently removes the photoresist in a short time. An object of the present invention is to provide a thinner composition for removing a photoresist.

  To achieve the above object, the present invention provides a thinner composition for removing a photoresist, comprising a) propylene glycol monoalkyl ether, b) alkyl acetate, and c) cycloketone.

  Preferably, the thinner composition comprises a) 10 to 90 parts by weight of propylene glycol monoalkyl ether, b) 10 to 70 parts by weight of alkyl acetate, and c) 1 to 70 parts by weight of cycloketone.

  The thinner composition of the present invention may further include a compound selected from the group consisting of d) a fluorinated acrylic copolymer and e) a polyethylene oxide-based condensate.

  Preferably, the thinner composition comprises a) 10 to 90 parts by weight of propylene glycol monoalkyl ether, b) 10 to 70 parts by weight of alkyl acetate, c) 1 to 70 parts by weight of cycloketone, and d) fluorinated acrylic copolymer 0. 0.001 to 1 part by weight may be included.

  In addition, the thinner composition comprises a) 10 to 90 parts by weight of propylene glycol monoalkyl ether, b) 10 to 70 parts by weight of alkyl acetate, c) 1 to 70 parts by weight of cycloketone, and e) polyethylene oxide condensate 0. 0.001 to 1 part by weight may be included.

  Also, the thinner composition comprises a) 10 to 90 parts by weight of propylene glycol monoalkyl ether, b) 10 to 70 parts by weight of alkyl acetate, c) 1 to 70 parts by weight of cycloketone, and d) fluorinated acrylic copolymer. 001 to 1 part by weight, and e) 0.001 to 1 part by weight of a polyethylene oxide-based condensate.

  The thinner composition for removing a photoresist according to the present invention is used on the periphery and back surface of a substrate used for manufacturing a liquid crystal display element, particularly a large glass substrate for organic EL, and can efficiently remove unnecessary photoresist in a short time. It can be removed at the same time, and the step difference at the interface can be reduced, and in particular, the phenomenon of penetration of the photoresist into the interface can be suppressed. Therefore, not only the economic advantage but also the simplification of the manufacturing process and the productivity can be improved. it can.

  Hereinafter, the present invention will be described in detail.

  The present invention is characterized in that the phenomenon of interfacial penetration into a photoresist can be suppressed, and is effective for use in the manufacture of semiconductor devices and liquid crystal display devices.

  Such a thinner composition for removing a photoresist of the present invention contains propylene glycol monoalkyl ether, alkyl acetate, and cycloketone.

  The propylene glycol monoalkyl ether, alkyl acetate and cycloketone used as solvents in the present invention are high purity and can be used in semiconductor grade, and in VLSI grade, those filtered at 0.1 μm level should be used. Is preferred.

  As the propylene glycol monoalkyl ether, those having an alkyl group having 1 to 5 carbon atoms can be used. Specific examples include propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, and propylene. It is preferable that at least one selected from the group consisting of glycol monobutyl ether. Among these, it is more preferable to use propylene glycol monomethyl ether having excellent solubility in polymers.

The propylene glycol monomethyl ether is harmless to the human body when exposed to the air and is rapidly decomposed into propylene glycol and alcohol by the human body. LD _50, which shows 50% lethal dose by oral administration to mice in toxicity experiments, is 4.4 g / kg and is rapidly degraded by hydrolysis. The boiling point is 132.8 ° C., the flash point (determined by closed cup method) is 32 ° C., the viscosity (at 25 ° C.) is 1.86 cps, the surface tension is 26.5 dyne / cm ² , and the solubility parameter is 10.4.

  The content of the propylene glycol monoalkyl ether is preferably 10 to 90 parts by weight with respect to 100 parts by weight of the total composition. If the content of the propylene glycol monoalkyl ether is less than 10 parts by weight, there is a problem that the dissolving power of the photosensitive film is lowered, and if it exceeds 90 parts by weight, the volatility is lowered and the thinner remains on the surface after drying. is there.

  Further, the alkyl acetate preferably has 1 to 4 carbon atoms in the alkyl group. Specifically, at least one selected from the group consisting of methyl acetate, ethyl acetate, isopropyl acetate, normal propyl acetate, and butyl acetate is selected. Is preferred. Among them, it is more preferable to use a solvent such as isopropyl acetate, normal propyl acetate or butyl acetate, which has a relatively low viscosity and an appropriate volatility. The amount of alkyl acetate used is preferably 10 to 70 parts by weight based on the total composition. If the content of the alkyl acetate is less than 10 parts by weight, the volatility of the thinner is reduced and the thinner remains on the substrate after drying. If the content exceeds 70 parts by weight, the thinner has a problem of decreasing the dissolving power. .

At this time, in the case of butyl acetate, which is one of the alkyl acetates, the solubility in various resins is excellent, especially the surface tension is low, the volatility is excellent, and even if only a small amount is added to the thinner composition. Excellent interfacial properties can be exhibited. The butyl acetate shows 50% lethal dose by oral administration to mice in toxicity experiments. LD ₅₀ shows 7.0 g / kg, decomposes rapidly by hydrolysis, has a boiling point of 126.1 ° C., flash point (closed cup side) Constant) 23 ° C., viscosity (at 25 ° C.) 0.74 cps, surface tension 25 dyne / cm ² .

  Examples of the cycloketone include cyclopentanone, cyclohexanone, and cycloheptanone. Among these, it is more preferable to use cyclohexanone having excellent solubility in various resins.

  The cycloketone is used in an amount of 1 to 70 parts by weight based on 100 parts by weight of the total composition. If the content of the cycloketone is less than 1 part by weight, there is a problem that the ability to remove a plurality of photosensitive films is reduced, and if it exceeds 70 parts by weight, there is a problem that the dissolving power is reduced with respect to the specific photosensitive film.

  In addition, the thinner composition of the present invention may further include a compound selected from the group consisting of a fluorinated acrylic copolymer and a polyethylene oxide-based condensate.

  Fluoroacrylic copolymer has excellent solubility in water and various solvents, and “Megaface R-08” manufactured by Dainippon Ink & Chemicals, Inc. is a commercial product.

  The content of the fluorinated acrylic copolymer is preferably 0.001 to 1 part by weight based on 100 parts by weight of the total composition. If the content of the copolymer is less than 0.001 part by weight, the dissolving power in the photoresist is remarkably reduced, and if it exceeds 1 part by weight, the dynamic surface tension is lowered at the interface to show excellent removal performance. On the other hand, bubbles may be generated violently, causing malfunction of the liquid level sensor during use.

  The fluorinated acrylic copolymer has a weight average molecular weight of 3000 to 10,000, a flash point (determined by an open cup system) 200 ° C., a specific gravity 1.10 g / ml (25 ° C.), and a viscosity (20 ° C.) 2100 cst. The surface tension is 24.0 mN / m (measured by the Wilhermy method) on ethyl lactate, and it is preferably diluted with ethyl lactate.

  The polyethylene oxide condensate acts as a nonionic surfactant, and specific examples thereof include linear or side chain alkyl groups having 6 to 12 carbon atoms and 5 per mole of the alkylphenol. Condensation products obtained by condensation of up to 25 moles of ethylene oxide are included. Here, the alkyl group of the alkylphenol may be derived from propylene, diisobutylene, octene or nonene. Examples of such condensates include nonylphenol condensed with about 9.5 moles of ethylene oxide per mole of phenol, dodecylphenol condensed with about 12 moles of ethylene oxide per mole of phenol, about 15 moles per mole of phenol. Examples include diisooctylphenol condensed with ethylene oxide. These compounds have excellent solubility in water and various solvents, and play a role in reducing the level difference at the interface when the thinner comes into contact with the photoresist. Commercialized products include the non-ionic monopol series from Tonan Gosei Co., Ltd.

  The polyethylene oxide-based condensate is preferably 0.001 to 1 part by weight with respect to 100 parts by weight of the total composition, and if the content is less than 0.001 part by weight, the volatilization of thinner at the edge of the substrate is performed. When it exceeds 1 part by weight, the bubbles are generated vigorously.

  After the photoresist is applied to the substrate using a coating machine, the thinner composition is removed by dropping or spraying on unnecessary photoresist on the edge and back of the substrate. The dropping amount or spraying amount of the thinner composition of the present invention can be adjusted according to the type of photoresist used and the thickness of the film, and the amount can be selected and used within the range of 5 to 100 cc / min. Is preferred. After spraying the thinner composition, a fine circuit pattern can be formed through a subsequent photolithography process.

  Hereinafter, the present invention will be described in more detail through examples. However, the following examples are for illustrating the present invention, and are not limited to these inventions.

  A substrate specimen was prepared as follows.

  A silicon oxide substrate having a diameter of 8 inches was used. These substrates were first washed in two baths each containing hydrogen peroxide and sulfuric acid (soaked for 5 minutes in each bath) and then rinsed with ultrapure water. This process was performed with specially designed cleaning equipment. Thereafter, the substrate was dried with a rotary dryer (product of VERTEQ, model SRD1800-6). Next, a photoresist was applied on the substrate to a certain thickness. The photoresist was applied using a spin coater (product of Koryo Semiconductor Co., Ltd., model EBR TRACK).

  In the spin coating operation, 10 cc of photoresist was dropped on the center of the stationary substrate. Thereafter, the photoresist was dispersed for 3 seconds at 500 rpm using a spin coater. Next, it was accelerated at a rotational speed of about 2000 to 4000 rpm and adjusted to a predetermined thickness. At this speed, the rotation time was about 20-30 seconds.

Examples 1-5 and Comparative Examples 1-5
The thinner compositions of Examples 1 to 5 and Comparative Examples 1 to 5 having compositions and contents as shown in Table 1 below were produced.

note)
1. PGME: Propylene glycol monomethyl ether,
2. PGMEA: Propylene glycol monoethyl ether acetate,
3. n-PE: normal propyl acetate,
4). CXN: cyclohexanone,
5). GBL: γ -butyrolactone,
6). OP-1015: Condensate prepared by condensing 5 moles of ethylene oxide per mole of octylphenol, “Monopol OP-1015” manufactured by Tonan Gosei Co., Ltd.
7). R-08: Fluoroacrylic copolymer, 'Megaface R-08' from Dainippon Ink & Chemicals, Inc.

Unnecessary photoresist removal experiment After each photoresist was applied to an 8-inch silicon oxide substrate, unnecessary photoresist on the edge was formed using the thinner compositions of Examples 1 to 7 and Comparative Examples 1 to 5. An experiment to remove the resist (edge bead removing experiment: hereinafter referred to as EBR experiment) was performed. The EBR experiment also used the spin coater that was used to apply the photoresist to the substrate.

  Each thinner composition shown in Table 1 was sprayed under the conditions shown in Table 3 through an EBR nozzle onto a substrate coated with the photoresist shown in Table 2 below. Each thinner composition was supplied from a pressurized container equipped with a pressure gauge, the pressurized pressure at this time was 1.0 kgf, and the flow rate of the thinner composition was 10 to 20 cc / min.

  The EBR experimental evaluation is shown in Table 4 below.

  In Table 4, “'” indicates that there is no penetration phenomenon into the photoresist interface during the EBR experiment, and “◯” indicates that the penetration phenomenon into the interface with respect to the photoresist is 80% or more in a linear state. The evaluation symbol “△” indicates that the penetration phenomenon into the interface with respect to the photoresist is in a linear state with 50% or more favorable, and the evaluation symbol “×” indicates that the penetration phenomenon is 20% or more favorable. This indicates that the film is in a straight line state, and that a film tailing phenomenon has occurred at the edge portion.

  As shown in Table 4, the thinner compositions of Examples 1 to 7 according to the present invention exhibited excellent EBR performance (suppression of penetration phenomenon) for all photoresists. In particular, the thinner compositions of Examples 5 and 7 showed very excellent EBR performance and permeation suppression performance. Therefore, it can be seen that a thinner composition containing a polyethylene oxide-based condensate, a fluorinated acrylic copolymer, or a mixture thereof as in the present invention has excellent photoresist removal performance.

  On the other hand, the thinner compositions of Comparative Examples 1 to 5 had a very low ability to suppress the penetration phenomenon into the photoresist. This acts as a factor that lowers the productivity of semiconductor elements and liquid crystal display elements in subsequent processes.

Claims (11)

a) with propylene glycol monoalkyl ether;
b) with alkyl acetate;
c) A thinner composition for removing a photoresist containing cycloketone. a) 10 to 90 parts by weight of propylene glycol monoalkyl ether;
b) 10 to 70 parts by weight of alkyl acetate;
The thinner composition according to claim 1, comprising 1 to 70 parts by weight of c) cycloketone.   The thinner composition according to claim 1, wherein the composition further comprises a compound selected from the group consisting of d) a fluorinated acrylic copolymer; and e) a polyethylene oxide-based condensate. a) 10 to 90 parts by weight of propylene glycol monoalkyl ether;
b) 10 to 70 parts by weight of alkyl acetate;
c) 1 to 70 parts by weight of a cycloketone;
d) A thinner composition according to claim 1, comprising 0.001 to 1 part by weight of a fluorinated acrylic copolymer. a) 10 to 90 parts by weight of propylene glycol monoalkyl ether;
b) 10 to 70 parts by weight of alkyl acetate;
c) 1 to 70 parts by weight of a cycloketone;
The thinner composition according to claim 1, comprising 0.001 to 1 part by weight of e) polyethylene oxide condensate. a) 10 to 90 parts by weight of propylene glycol monoalkyl ether;
b) 10 to 70 parts by weight of alkyl acetate;
c) 1 to 70 parts by weight of a cycloketone;
d) 0.001 to 1 part by weight of a fluorinated acrylic copolymer;
The thinner composition according to claim 1, comprising 0.001 to 1 part by weight of e) polyethylene oxide condensate.   The thinner composition according to claim 1, wherein the propylene glycol monoalkyl ether is selected from the group consisting of propylene glycol monomethyl ether, propylene glycol monoethyl ether, propylene glycol monopropyl ether, and propylene glycol monobutyl ether.   The thinner composition according to claim 1, wherein the alkyl acetate is selected from the group consisting of methyl acetate, ethyl acetate, isopropyl acetate, normal propyl acetate, and butyl acetate.   The thinner composition according to claim 1, wherein the cycloketone is selected from the group consisting of cyclopentanone, cyclohexanone, and cycloheptanone.   The thinner composition according to claim 3, wherein the fluorinated acrylic copolymer has a weight average molecular weight of 3000 to 10,000. The polyethylene oxide-based condensate is a condensation product of an alkylphenol having a linear or side-chain C _{6 to} C ₁₂ alkyl group and 5 to 25 moles of ethylene oxide per mole of such alkylphenols. The thinner composition described in 1.