TW201418452A - Slurry for removing residual photoresist - Google Patents

Abstract

The invention relates to photo-resist strippers. The photo-resist stripper includes fluoride, organic solvent, water, oxidant and chelating agent. And the photo-resist stripper does not include nano/micro, organic/inorganic particle. The stripper could remove the photo-resist on the wafer, and inhibit the corrosion of substrates, such as aluminium, and silica dioxide. The stripper possesses the potential application prospect in cleaning semiconductor wafer.

Description

Cleaning liquid for removing photoresist residue

The present invention relates to a cleaning solution, and more particularly to a cleaning solution for removing photoresist residues.

In the fabrication of semiconductor components, the application, exposure and imaging of the photoresist layer are necessary process steps for the pattern fabrication of the components. The residue of the photoresist layer material needs to be completely removed before the next process step (ie, after coating, imaging, ion implantation, and etching of the photoresist layer). In the doping step, ion bombardment hardens the photoresist polymer, thus making the photoresist layer less soluble and more difficult to remove. Up to now, in the semiconductor manufacturing industry, this layer of photoresist film has been removed using a two-step process (dry ashing and wet etching). In the first step, the majority of the photoresist layer (PR) is removed by dry ashing; the second step is to remove and clean the remaining photoresist layer by a wet etching/cleaning process of the corrosion inhibitor composition, the steps of which are generally cleaning. Liquid cleaning / rinsing / drying. Only the residual polymer photoresist layer and inorganic matter can be removed in this process, and the damage to the metal layer such as the aluminum layer cannot be attacked.

In the current wet cleaning process, the most used cleaning solution is hydroxy Amine and fluorinated cleaning solutions, and typical examples of hydroxylamine cleaning fluids are US 6,319,885, US 5,672,577, US 6,030,932, US 6,825,156 and US 5,419,779. After continuous improvement, the corrosion rate of the solution itself to the metal aluminum has been greatly reduced, but this kind of cleaning liquid has a single source and is easy to explode due to the use of hydroxylamine. However, existing fluoride-based cleaning solutions have been greatly improved, such as US 5,972,862, US 6,828,289, etc., but there is still a good control of the corrosion of metal and non-metal substrates at the same time, and it is easy to cause channel characteristics after cleaning. Size changes. The third type of cleaning solution currently in use in the industry is a cleaning solution containing neither hydroxylamine nor fluoride. For example, US 5,988,186 discloses a cleaning solution containing a solvent, an alcohol amine, water, and gallic acid and esters thereof, which solves the problem of single source and safety and environmental protection of hydroxylamine, and solves the problem of non-metal of fluorine-containing cleaning liquid. The problem of unstable corrosion rate. However, such cleaning liquids often have great limitations in use because they contain neither hydroxylamine nor fluoride.

Therefore, although some cleaning fluid compositions have been disclosed, it is still necessary to prepare a cleaning fluid that is more versatile.

The technical problem to be solved by the present invention is to provide a semiconductor wafer cleaning solution capable of removing photoresist residue on a wafer, which has a small corrosion rate for metal aluminum and non-metal cerium oxide.

In order to solve the above technical problems, the present invention provides a novel cleaning liquid containing a fluoride, an organic solvent, water, an oxidizing agent, and a chelating agent.

Wherein, the content of the fluoride is 0.05-20% by weight (mass%).

The content of the organic solvent is from 10 to 75% by weight, preferably from 20 to 60% by weight.

Among them, the water content is from 15 to 85% by weight.

The content of the oxidizing agent is from 0.1 to 10% by weight, preferably from 0.5 to 5% by weight.

Wherein, the content of the chelating agent is 0.05-20% by weight.

Among them, the fluoride is preferably one or more selected from the group consisting of hydrogen fluoride, ammonium fluoride, ammonium hydrogen fluoride, tetramethylammonium fluoride, and trishydroxyethyl ammonium fluoride.

Wherein, the organic solvent is preferably one or more of an anthracene, an anthracene, an imidazolidinone, a pyrrolidone, an imidazolidinone, a guanamine, an alcohol, an alcohol amine, and an alcohol ether; and the hydrazine is preferably a dimethyl hydrazine. And one or more of methyl ethyl hydrazine; the hydrazine is preferably one or more of methyl hydrazine and cyclobutyl hydrazine; the imidazolidinone is preferably 2-imidazolidinone and 1,3-di One or more of methyl-2-imidazolidinone; the pyrrolidone is preferably one or more of N-ethylpyrrolidone, N-cyclohexylpyrrolidone and N-hydroxyethylpyrrolidone; the imidazolidinone is preferably 1,3-Dimethyl-2-imidazolidinone; the decylamine is preferably one or more of dimethylformamide and dimethylacetamide; the alcohol is preferably isopropanol, propylene glycol and One or more of glycerol; the alcohol amine is preferably one or more of ethanolamine, diethanolamine, triethanolamine; the alcohol ether is preferably one or more of ethylene glycol alkyl ether and propylene glycol alkyl ether. . The ethylene glycol alkyl ether is preferably one or more of ethylene glycol monoethyl ether, diethylene glycol monomethyl ether and diethylene glycol monobutyl ether; the propylene glycol alkyl ether is preferably propylene glycol monomethyl ether, One or more of propylene glycol monobutyl ether and dipropylene glycol monomethyl ether.

Among them, the oxidizing agent is preferably one or more of hydrogen peroxide, persulfuric acid, ammonium persulfate, peracetic acid, and ammonium peroxyacetate.

Among them, the chelating agent is preferably one or more of an organic polyamine and an organic polybasic acid. The organic polyamine is preferably one or more of diethylenetriamine, pentamethyldiethylenetriamine and polyethene polyamine; the organic polybasic acid is preferably oxalic acid, malonic acid, succinic acid, pentane Diacid, adipic acid, citric acid, tartaric acid, malic acid, fumaric acid, maleic acid, phthalic acid, isophthalic acid, terephthalic acid, iminodiacetic acid, ammonia triacetic acid, ethylenediamine One or more of tetraacetic acid, trans-1,2-cyclohexanediaminetetraacetic acid.

In the cleaning liquid of the present invention, the photoresist residue on the wafer can be cleaned at 20 ° C to 50 ° C. The specific method is as follows: the wafer containing the photoresist residue is immersed in the cleaning liquid in the present invention, immersed at 20 ° C to 50 ° C for 10-30 min, taken out and rinsed, and then blown dry with high-purity nitrogen gas.

The positive effects of the present invention are:

1) The cleaning liquid of the present invention can remove the photoresist residues on the wafer which cannot be completely removed by the fluorine-containing system by the combination of the fluoride and the oxidizing agent, and at the same time achieve corrosion of the metal aluminum and the non-metal cerium oxide. inhibition;

2) The cleaning solution of the invention solves the problems of single source, high price and easy explosion of hydroxylamine in the traditional hydroxylamine cleaning solution.

The reagents and starting materials used in the present invention are commercially available. The cleaning liquid of the present invention can be obtained by simply and uniformly mixing the above components.

The advantages of the present invention are further illustrated by the following specific examples, but the scope of the present invention is not limited only to the following examples.

The polishing liquid was prepared in accordance with the ingredients of the respective examples in Table 1 and their ratios, and mixed uniformly.

Effect embodiment

In order to further investigate the cleaning of the cleaning liquid, the present invention adopts the following technical means: the metal pad (Pad) wafer containing the photoresist residue is immersed in each cleaning liquid as shown in Table 2 at 20 ° C. Use constant temperature vibration to 50 °C The vortexer was shaken at a vibration frequency of about 60 rpm for 10 to 30 minutes, then washed by rinsing and then dried with high purity nitrogen. 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 liquid of the present invention has a good cleaning effect on a wafer containing a photoresist residue (Pad), and has a wide temperature range. From Comparative Example 1 and Example 8 and Comparative Example 2 and Example 10, it can be seen that in the same fluorine-containing system, that is, in Comparative Examples 1 and 2, under the same conditions of other components, since no oxidizing agent is added, the light is applied thereto. The residue is not thoroughly cleaned and remains on the wafer. Under the same operating conditions, the system in which the oxidizing agent was added, that is, Examples 8 and 10, was effective in removing the residue, indicating that the addition of the oxidizing agent facilitated the removal of the photoresist residue. It can also be seen from Table 2 that the cleaning solution of the present invention does not corrode metallic aluminum and non-metallic cerium oxide while effectively removing photoresist residues.

It should be understood that the wt% of the present invention refers to the mass percentage content.

The specific embodiments of the present invention have been described in detail above, but are merely exemplary, and the invention is not limited to the specific embodiments described above. Any equivalent modifications and substitutions to the invention are also within the scope of the invention. Accordingly, equivalents and modifications may be made without departing from the spirit and scope of the invention.

Claims (16)

A cleaning solution for removing photoresist residues, comprising fluoride, organic solvent, water, oxidant, and chelating agent. The cleaning liquid according to claim 1, wherein the fluoride is contained in an amount of from 0.05 to 20% by weight. The cleaning liquid according to claim 1, wherein the organic solvent is contained in an amount of 10 to 75 wt%. The cleaning liquid according to claim 3, wherein the organic solvent is contained in an amount of 20 to 60% by weight. The cleaning liquid according to claim 1, wherein the water is contained in an amount of from 15 to 85% by weight. The cleaning solution according to claim 1, wherein the oxidizing agent is contained in an amount of 0.1 to 10% by weight. The cleaning liquid according to claim 6, wherein the oxidizing agent is contained in an amount of from 0.5 to 5% by weight. The cleaning solution according to claim 1, wherein the chelating agent is contained in an amount of from 0.05 to 20% by weight. The cleaning solution according to claim 1, wherein the fluoride is selected from one or more of hydrogen fluoride, ammonium fluoride, ammonium hydrogen fluoride, tetramethylammonium fluoride, and trishydroxyethyl ammonium fluoride. The cleaning solution according to claim 1, wherein the organic solvent is one or more selected from the group consisting of anthraquinone, anthracene, imidazolidinone, pyrrolidone, imidazolidinone, decylamine, an alcohol, an alcohol amine, and an alcohol ether. The cleaning solution according to claim 10, wherein the hydrazine is selected from one or more of dimethyl hydrazine and methyl ethyl hydrazine, and the hydrazine is selected from the group consisting of methyl hydrazine and cyclo hydrazine. One or more of the oxime; the imidazolidinone is selected from one or more of 2-imidazolidinone and 1,3-dimethyl-2-imidazolidinone; the pyrrolidone is selected from the group consisting of N-ethyl One or more of pyrrolidone, N-cyclohexylpyrrolidone and N-hydroxyethylpyrrolidone; said imidazolidinone is 1,3-dimethyl-2-imidazolidinone; said guanamine is selected from the group consisting of dimethyl One or more of carbamide and dimethyl acetamide; the alcohol is selected from one or more of isopropanol, propylene glycol and glycerol; the alcohol amine is selected from the group consisting of ethanolamine, diethanolamine, One or more of triethanolamine; the alcohol ether is selected from one or more of ethylene glycol alkyl ether and propylene glycol alkyl ether. The cleaning solution according to claim 11, wherein the ethylene glycol alkyl ether is one or more selected from the group consisting of ethylene glycol monoethyl ether, diethylene glycol monomethyl ether and diethylene glycol monobutyl ether; The propylene glycol alkyl ether is selected from one or more of propylene glycol monomethyl ether, propylene glycol monobutyl ether and dipropylene glycol monomethyl ether. The cleaning solution according to claim 1, wherein the oxidizing agent is one or more selected from the group consisting of hydrogen peroxide, persulfuric acid, ammonium persulfate, peroxyacetic acid, and ammonium peroxyacetate. The cleaning solution according to claim 1, wherein the chelating agent is selected from one or more of an organic polyamine and an organic polybasic acid. The cleaning solution according to claim 14, wherein the organic polyamine is one or more selected from the group consisting of diethylenetriamine, pentamethyldiethylenetriamine, and polyethene polyamine; and the organic polybasic acid is selected from the group consisting of Oxalic acid, malonic acid, succinic acid, glutaric acid, adipic acid, citric acid, tartaric acid, malic acid, fumaric acid, maleic acid, phthalic acid, isophthalic acid, terephthalic acid One or more of iminodiacetic acid, ammonia triacetic acid, ethylenediaminetetraacetic acid, and trans-1,2-cyclohexanediaminetetraacetic acid Kind. The cleaning solution of claim 1, wherein the cleaning solution does not contain inorganic and/or organic nanoparticles and/or microparticles.