TWI696898B - Cleaning liquid for photoresist residue removal - Google Patents

Abstract

This invention related to a kind of cleaning liquid used for removing photoresist residue, wherein, it contains alkanolamine, esters and non-ester solvent. This cleaning liquid has a low corrosion rate for metal or non-metal materials and has a better compatibility with quartz device.

Description

Photoresist residue cleaning solution

The invention discloses a cleaning solution for photoresist residues.

In the general LED and semiconductor manufacturing process, by forming a photoresist mask on the surface of some materials, the pattern is transferred after exposure, and after obtaining the desired pattern, the remaining photoresist needs to be stripped off before the next process. . In this process, it is required to completely remove the unnecessary photoresist, and at the same time, it cannot corrode any substrate.

At present, the photoresist cleaning solution is mainly composed of polar organic solvents, strong alkalis, and/or water. The photoresist on the semiconductor wafer is removed by immersing the semiconductor wafer in the cleaning solution or washing the semiconductor wafer with the cleaning solution. One of them is a photoresist cleaning solution containing water, the water content of which is generally greater than 5%; for example, JP1998239865 discloses a cleaning solution of an aqueous system, which consists of tetramethylammonium hydroxide (TMAH) and dimethyl sulfoxide (DMSO) ), 1,3'-dimethyl-2-imidazolidinone (DMI) and water. Immerse the wafer in the cleaning solution to remove the photoresist of more than 20 μm on the metal and dielectric substrates at 50-100°C; its corrosion of the semiconductor wafer substrate is slightly higher, and the photoresist on the semiconductor wafer cannot be completely removed, Insufficient cleaning ability; for example, US5529887 discloses an alkaline cleaning solution composed of potassium hydroxide (KOH), alkyl glycol monoalkyl ether, water-soluble fluoride, and water. The wafer is immersed in the cleaning solution at 40~ Remove photoresist on metal and dielectric substrates at 90°C. The corrosion of the semiconductor wafer substrate is relatively high. In this type of cleaning solution, Contains free strong basic group -OH, and there is water, so it will often cause certain corrosion to the metal substrate. The other type is photoresist cleaning liquid that does not substantially contain water, and its water content is generally less than 5%, or even contains substantially no water. For example, US5480585 discloses a cleaning solution containing a non-aqueous system, the composition of which is ethanolamine, cyclobutane or dimethylsulfoxide and catechol, which can remove the photoresist on the metal and dielectric substrate at 40~120 ℃, Basically no corrosion to metal. For another example, US2005119142 discloses a non-aqueous cleaning solution containing an alkoxy group polymer, dipropylene glycol alkyl ether, N-methylpyrrolidone and methyl isobutyl ketone. The cleaning solution can be used for cleaning both positive photoresist and negative photoresist. Non-aqueous photoresist cleaning liquid does not contain water, so it has no corrosion to metal substrates; however, when this type of cleaning liquid is mixed with a small amount of water in the operating system, the corrosion rate of its metal will increase significantly, resulting in metal-based Corrosion of wood. Therefore, there is a problem that the operation window is small.

The object of the present invention is to provide a composition and application of a photoresist stripping solution for effectively removing photoresist residues. This photoresist cleaning liquid has the ability to quickly remove the photoresist in the semiconductor, at the same time it has a very low etching rate for metal aluminum and the like, and also has good water resistance. The photoresist cleaning liquid can not only effectively remove the photoresist but also protect the metal, and can also prevent the metal corrosion rate from increasing due to water absorption.

The purpose of the present invention is to provide a low-cost semiconductor wafer cleaning liquid capable of removing photoresist residues on a wafer, which does not contain water, hydroxylamine and fluoride, and the cleaning liquid has a low corrosion rate to metals and non-metals And compatible with quartz equipment.

The cleaning solution of the present invention contains: i. alcohol amine 1%-40%, preferably 1-30%; ii. ester 1%-40%, preferably 1%-30%; iii. non-ester solvent, balance.

Among them, the above-mentioned contents are all quality percentage contents and do not contain water, hydroxylamine and fluoride.

In the present invention, the alcohol amine is selected from monoethanolamine, N-methylethanolamine, diethanolamine, triethanolamine, isopropanolamine, ethyldiethanolamine, N,N-diethylethanolamine, N-(2- One or more of aminoethyl)ethanolamine and diethylene glycolamine.

In the present invention, the esters are selected from ethyl acetate, isoamyl acetate, propyl acetate, ethyl 2-methylbutyrate, ethyl hexanoate, ethyl 1,2-dimethylbutyrate, ethylene glycol One of carbonate, 1,2-propanediol carbonate, 1,4-butanediol diacrylate, 1,4-butanediol diacetate, pentaerythritol phosphate, phosphate and lauryl ether phosphate Multiple.

In the present invention, the non-ester solvent is selected from one or more of sulfonamide, ash, imidazolidone, pyrrolidone, imidazolinone, amide and alcohol ether. Preferably, the sulfonamide is selected from one or more of dimethyl sulfoxide and methylethyl sulfoxide; the benzene is selected from one or more of methyl sulfoxide and cyclobutane; the imidazolidone is selected from 2-imidazolidinone and One or more of 1,3-dimethyl-2-imidazolidinone; one or more of pyrrolidone selected from N-methylpyrrolidone and N-cyclohexylpyrrolidone; imidazolinone selected from 1,3-dimethyl Yl-2-imidazolidinone; amides are selected from one or more of dimethylformamide and dimethylacetamide; alcohol ethers are selected from the group consisting of diethylene glycol monobutyl ether and dipropylene glycol monomethyl ether One or more.

The cleaning solution in the present invention can clean the photoresist residue on the wafer at 50°C to 95°C. The specific method is as follows: the LED metal pad (Pad) wafers containing photoresist residues are immersed in the above cleaning solution, and oscillated at a vibration frequency of about 60 rpm at a temperature of 50 rpm to 95 ℃ for 10 to 30 at a temperature of 50 to 95 Minutes, then rinse with high-purity nitrogen after rinsing.

The positive effects of the present invention are as follows: 1) The cleaning solution of the present invention can effectively remove the photoresist residues on the wafer through the action of alcohol amines, esters, and non-ester solvents. Very low corrosion of metal aluminum etc. 2) The cleaning solution of the present invention solves the problems of single source of hydroxylamine, expensive, explosive, fluoride is not environmentally friendly, and large corrosion in the traditional hydroxylamine cleaning solution; 3) the cleaning solution of the present invention has very good water resistance, It solves the problem of increased corrosion caused by the absorption of water in the cleaning operation of the traditional cleaning liquid, and has a good application prospect in the field of semiconductor wafer cleaning and the like.

The advantages of the present invention are further described below through specific embodiments, but the protection scope of the present invention is not limited to the following embodiments.

The reagents and raw materials used in the present invention are commercially available. The cleaning solution of the present invention can be prepared by simply and uniformly mixing the above components.

Prepare the cleaning solution according to the ingredients and proportions of the examples in Table 1, mix them evenly, and make up the quality percentage to 100% with the solvent.

Effect example

In order to further investigate the cleaning situation of this type of cleaning liquid, the present invention adopts the following technical means: that is, immersing the LED metal pad (Pad) wafers containing photoresist residues in the cleaning liquid respectively, at 50 ℃ to 95 ℃ Use a constant temperature oscillator to oscillate at a vibration frequency of about 60 rpm for 10 to 30 minutes, then rinse with high-purity nitrogen after rinsing. The cleaning effect of the photoresist residue and the corrosion of the cleaning solution on the wafer are shown in Table 2.

As can be seen from Table 2, the cleaning solution of the present invention has a good cleaning effect on LED metal pad (Pad) wafers containing photoresist residues and has a wide temperature range.

As can be seen from Comparative Example 1-1 and Example 1, in Example 1, an ester compound is used as the corrosion inhibitor. With the addition of the ester substance, Example 1 compares to Comparative Example 1-1 on the corrosion inhibition of aluminum metal. Better, so Comparative Example 1-1 and Example 1 verified that the addition of esters is beneficial to the suppression of metal aluminum corrosion. Similarly, with the addition of esters in Comparative Examples 1-2, the other components are the same and the operating conditions are the same, it is verified that the addition of esters is beneficial to the suppression of metal aluminum corrosion, and it can be seen that the Comparative Examples 1-1 and 1-2 are not as good as in Example 1 in inhibiting corrosion of metallic aluminum. It can be seen from the effect examples of the above Comparative Examples 1-1, 1-2 and Example 1, that with the addition of the ester substance, the corrosion of metallic aluminum can be better suppressed.

The comparison between Comparative Example 1-1 and Example 1 verifies that the corrosion of the metal is more severe without the addition of esters. Comparison of Comparative Examples 1-1, 1-2, 1-3, 1-4 and Example 1 verifies that the amount of esters added exceeds a certain range, although it has a good suppression of metal corrosion, but it has a photoresist resistance The cleaning effect is great, with a large amount of photoresist remaining.

In summary, the positive progress of the present invention is that the cleaning solution of the present invention can effectively remove photoresist residues and protect the substrate, and can also prevent the problem of increased metal corrosion rate caused by water absorption. The field has good application prospects.

The specific embodiments of the present invention have been described in detail above, but they are only used as examples, and the present invention is not limited to the specific embodiments described above. For those skilled in the art, any equivalent modifications and substitutions to the present invention are also within the scope of the present invention. Therefore, equivalent transformations and modifications made without departing from the spirit and scope of the present invention should be covered within the scope of the present invention.

Claims (9)

A cleaning liquid for photoresist residues, the cleaning liquid includes alcohol amines, esters and non-ester solvents, wherein the esters are selected from ethyl acetate, isoamyl acetate, propyl acetate, and 2-methylbutyrate Ethyl acetate, ethyl hexanoate, ethyl 1,2-dimethylbutyrate, ethylene glycol carbonate, 1,2-propylene glycol carbonate, 1,4-butanediol diacrylate, 1,4- One or more of butanediol diacetate, pentaerythritol phosphate, phosphate, and lauryl ether phosphate. . The photoresist residue cleaning solution according to claim 1, wherein the alcoholamine is selected from monoethanolamine, N-methylethanolamine, diethanolamine, triethanolamine, isopropanolamine, ethyldiethanolamine, N,N -One or more of diethylethanolamine, N-(2-aminoethyl)ethanolamine and diethylene glycolamine. The photoresist residue cleaning solution according to claim 1, wherein the non-ester solvent is one or more selected from the group consisting of sulfonamide, ash, imidazolidone, pyrrolidone, imidazolinone, amide, and alcohol ether. The photoresist residue cleaning solution according to claim 3, wherein the arsenic is selected from one or more of dimethyl arsenic and methyl ethyl arsenic; the arsenic is selected from the group consisting of methyl cerium and cyclobutan One or more; imidazolidone is selected from one or more of 2-imidazolidone and 1,3-dimethyl-2-imidazolidone; pyrrolidone is selected from N-methylpyrrolidone and N-cyclohexylpyrrolidone One or more; imidazolinone is selected from 1,3-dimethyl-2-imidazolidinone; amide is selected from one or more of dimethylformamide and dimethylacetamide; alcohol ether is selected from One or more of diethylene glycol monobutyl ether and dipropylene glycol monomethyl ether. The photoresist residue cleaning solution according to claim 1, wherein the content of the alcohol amine is 1%-40%. The photoresist residue cleaning solution according to claim 1, wherein the content of the alcohol amine is 1-30%. The photoresist residue cleaning solution according to claim 1, wherein the content of the ester is 1%-40%. The preferred photoresist residue cleaning solution according to claim 1, wherein the content of the ester is 1%-30%. The photoresist residue cleaning solution according to claim 1, which does not contain water, hydroxylamine and fluoride.