TW202424173A - Semi-water-based wafer substrate cleaning solution composition and use method thereof - Google Patents

Abstract

The invention provides a semi-aqueous wafer substrate cleaning solution composition. The semi-aqueous wafer substrate cleaning solution composition comprises organic alcohol amine, a polar organic solvent, [gamma]-butyrolactone, a corrosion inhibitor and water, wherein the weight ratio of the organic alcohol amine to the gamma-butyrolactone to the water is (1-80): (30-2): (40-1). The invention also provides a use method of the semi-water-based wafer substrate cleaning solution composition, which comprises the following steps of: providing a patterned wafer with polymer impurities after etching and photoresist removal. The method comprises the following steps: soaking or spraying a patterned wafer with the semi-aqueous wafer substrate cleaning solution composition to remove polymer impurities; and cleaning the patterned wafer with deionized water after the polymer impurities are removed.

Description

Semi-aqueous wafer substrate cleaning liquid composition and use method thereof

The present invention relates to the technical field of semiconductor wafer manufacturing process wet electronic chemicals, and specifically relates to a semi-aqueous wafer substrate cleaning liquid composition suitable for stripping and removing photoresist, photoresist residues and etching residues on a wafer and a method for using the same.

In the back-end of line preparation process of microelectronic components on aluminum (Al) or aluminum/copper (Cu) metallized substrates, an essential step is to deposit a photoresist film on the wafer substrate, and then use the photoresist as a mask to form a circuit pattern. After baking and developing, the resulting pattern is then transferred to the underlying substrate material (electrolyte or metal layer) through a reactive plasma etching gas. During the plasma etching process, due to the interaction between the plasma gas, the etching substrate material and the photoresist, etching residues will be formed on the side walls or around the etching substrate, and at the same time, the photoresist mask material will be cross-linked, making it more difficult to remove.

After etching is completed, the photoresist mask and etching residues must be removed from the patterned wafer in order to proceed to the next step. Currently, the mainstream cleaning step of Al or Al(Cu) metallization substrates after etching and removing the photoresist mask (ashing) is to use hydroxylamine cleaning fluids. The advantage of hydroxylamine cleaning fluids is that they can effectively remove various insoluble inorganic residues and organic residues. However, the operating temperature of hydroxylamine cleaning agents is usually above 65 ^o C, and hydroxylamine is very unstable and has the risk of explosion at higher operating temperatures. At the same time, the higher operating temperature will cause the rapid decomposition of system components and the volatility of water, making the tank life of hydroxylamine cleaning fluids usually only about 1000 minutes, and constant replenishment is required to maintain the tank life.

In addition, after the etched and ashed patterned wafer is treated with a hydroxylamine cleaning solution, it needs to be rinsed with an organic solvent such as isopropanol ( IPA) or N-methylpyrrolidone (NMP) before being rinsed with deionized water to avoid corrosion of the metal substrate on the surface of the patterned wafer, thereby increasing the wafer manufacturing cost. In addition, due to the high risk of manufacturing and purification processes of hydroxylamine, the source of hydroxylamine is single. Currently, electronic-grade hydroxylamine is exclusively supplied by BASF, and the price is extremely expensive.

Due to the various problems existing in current hydroxylamine cleaning fluid products, there is an urgent need to develop a non-hydroxylamine cleaning fluid with excellent cleaning performance, stability, and a larger operating window.

In order to solve the various problems of the above-mentioned prior art, after detailed research, the present invention provides a semi-aqueous wafer substrate cleaning liquid composition suitable for the field of semiconductor process, which has good stability and excellent removal performance for sidewall polymer impurities and residual photoresist on patterned wafers after etching and ashing, and at the same time will not corrode the substrate materials of the process such as aluminum, aluminum/copper, aluminum/silicon/copper, titanium, titanium nitride, titanium/tungsten, tungsten, silicon oxide, polycrystalline silicon, etc.

The semi-aqueous wafer substrate cleaning liquid composition of the present invention comprises: organic alcohol amine, polar organic solvent, γ-butyrolactone, buffer and water, wherein the weight ratio of organic alcohol amine, γ-butyrolactone and water is 1-80:30-2:40-1.

The method for using the semi-aqueous wafer substrate cleaning liquid composition of the present invention comprises: providing a patterned wafer after etching and removing the photoresist, which has polymer impurities; soaking or spraying the patterned wafer with the semi-aqueous wafer substrate cleaning liquid composition of the present invention to remove the polymer impurities; and cleaning the patterned wafer after removing the polymer impurities with deionized water.

Since the semi-aqueous wafer substrate cleaning liquid composition of the present invention does not contain hydroxylamine and has good stability, it has excellent performance in removing residual sidewall polymer impurities on patterned wafers after etching and ashing, and will not corrode the substrate material. It also has substantial characteristics such as a wide range of implementation and a large operating window.

In order to enable persons familiar with the art to understand the purpose, features and effects of the present invention, the present invention is described in detail as follows through the following specific embodiments and in conjunction with the attached drawings.

The following is a more detailed description of the implementation of the present invention so that those familiar with the art can understand the technical features and technical effects of the present invention after reading this manual.

The terms used herein are used only to describe specific embodiments and are not intended to limit the present invention. Unless the context clearly indicates otherwise, the singular forms of the terms "a", "an" and "the" used herein are intended to include the plural forms as well. The term "and/or" used herein includes any and all combinations of one or more of the relevant listed items. "Ashing" as used herein refers to the step of removing the photoresist mask in the semiconductor lithography process.

The semi-aqueous wafer substrate cleaning liquid composition of the present invention comprises an organic alcohol amine, a polar organic solvent, γ-butyrolactone, a buffer and water, wherein the weight ratio of the organic alcohol amine, γ-butyrolactone and water is 1-80:30-2:40-1. Calculated by the overall weight percentage of the semi-aqueous wafer substrate cleaning liquid composition, the weight ratio of the organic alcohol amine may be between 1-80%, such as 2-50%; the weight ratio of the polar organic solvent may be between 10-75%, such as 30-50%; the weight ratio of γ-butyrolactone may be between 2-30%, such as 5-20%; the weight ratio of the buffer may be between 1-20%, such as 2-10%; and the weight ratio of water may be between 1-40%, such as 10-30%.

Specifically, the organic alcoholamine can be selected from at least one of monoethanolamine, N,N-dimethylethanolamine, N,N-diethylethanolamine, isopropanolamine, diisopropanolamine, triisopropanolamine, diethanolamine, triethanolamine, 3-propanolamine, 2-aminoethanolamine, ethyldiethanolamine, N-(2-aminoethyl)ethanolamine and diglycolamine. Preferred organic alcoholamines include monoethanolamine, diglycolamine, N-methylethanolamine and N'N-dimethylethanolamine.

Specifically, the polar organic solvent is selected from at least one of formamide, N-methylformamide, N-methylacetamide, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, tetrahydrothiophene sulfone (cyclobutane sulfone), acetonitrile, benzonitrile, N-methyl-pyrrolidone, N-ethyl-pyrrolidone, 1-cyclohexyl-2-pyrrolidone, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, hexamethylenetetramine, and propylene carbonate.

The γ-butyrolactone in the semi-aqueous wafer substrate cleaning liquid composition of the present invention will slowly hydrolyze under strong alkaline conditions. The hydrolysis of γ-butyrolactone is reversible. Under neutral conditions, lactone is generated again, which has a certain weak acidity and has the effect of a corrosion inhibitor. In addition, in terms of solubility, it has good solubility in various oils and fats, and is also an excellent solvent.

Specifically, the buffer can be selected from at least one of phenol and its derivative compounds. Preferred phenol and its derivative compounds include phenol, 4-methylphenol, 3,4-dicarboxyphenol, o-catechol, resorcinol, hydroquinone, 3-methyl o-catechol, 4-methyl o-catechol, 3-carboxy o-catechol, 4-carboxy o-catechol, dimethyl o-catechol, 3-tert-butyl o-catechol, 4-tert-butyl o-catechol, o-catechol acetate, trihydroxybenzene, gallic acid, methyl gallate, ethyl gallate, n-propyl gallate, isopropyl gallate, and n-butyl gallate.

To prepare the semi-aqueous wafer substrate cleaning liquid composition of the present invention, the above components only need to be added to pure water in sequence and stirred to dissolve. During the dissolution process, the exothermic phenomenon of the organic base should be controlled and the temperature of the entire dissolution process should be controlled below 50 degrees. After the dissolution is complete, it can be filtered with a filter element below 0.1 μm.

Specifically, the patterned wafer is formed with at least one of a metal pad, a metal line, and a through hole.

Specifically, the temperature for removing polymer impurities using the semi-aqueous wafer substrate cleaning liquid composition is between 40-75 ^° C.

Specifically, the time for removing polymer impurities using the semi-aqueous wafer substrate cleaning liquid composition is between 10 and 120 minutes.

The semi-aqueous wafer substrate cleaning liquid composition of the present invention has no special restrictions during use, and can be used in an immersion or spraying manner.

In order to enable those who are familiar with the technical field to which the present invention belongs and have ordinary knowledge to further understand the present invention and implement it accordingly, the present invention is described in detail through the following specific embodiments.

The compositions of the embodiments and comparative examples are shown in Table 1.

Table 1 Embodiment Organic alcohol amine Polar organic solvents Etch inhibitor γ-Butyrolactone water Name Content wt% Name Content wt% Name content Content Wt% Content Wt% 1 Isopropanolamine 10 Dimethyl sulfoxide 25 4-Carboxy-o-Catechol 15 20 30 2 Monoethanolamine 10 N-Methylpyrrolidone 20 Ophthalmic acid 10 5 15 Triethanolamine 30 Diethylene glycol monomethyl ether 10 3 Diglycolamine 10 Diethylene glycol butyl ether 50 Gallic acid 15 10 5 Diethanolamine 10 4 N,N-Dimethylethanolamine 10 N-Methylformamide 50 phenol 6 11 13 Ethanolamine 5 N-Methylacetamide 5 5 N-Methylethanolamine 13 Diethylene glycol butyl ether 37 Ophthalmic acid 5 10 30 Gallic acid 5 6 Diisopropylamine 30 Dimethyl sulfoxide 10 Methyl Gallate 8 20 20 Triisopropanolamine 6 N-Methylpyrrolidone 6 7 Ethanolamine 50 Formamide 10 Trihydroxybenzene 5 15 20 8 3-Propanolamine 30 Diethylene glycol dimethyl ether 40 4-tert-Butyl o-catechol 8 5 17 9 N-Methylethanolamine 15 Diethylene glycol dimethyl ether 50 Resorcinol 5 10 20 10 Isopropanolamine 20 N-Methylacetamide 40 Methyl Gallate 5 10 25 Comparative Example 1 Isopropanolamine 20 N-Methylacetamide 50 Methyl Gallate 5 25 Comparative Example 2 Isopropanolamine N-Methylacetamide 60 Methyl Gallate 5 10 25 Comparative Example 3 Isopropanolamine 20 N-Methylacetamide 65 Methyl Gallate 5 10

In order to test the effect of the semi-aqueous wafer substrate cleaning liquid composition of the present invention, an 8-inch patterned wafer after etching and ashing was cut into samples of 10 cm * 10 cm small pieces. The etched pattern includes at least one of a metal pad, a metal line, and a via. Then, the sample was cleaned by immersion or spraying with the cleaning liquid of the above-mentioned embodiment and comparative example. The cleaned sample was cleaned with deionized water and dried with nitrogen. The cleaning effect and substrate corrosion were evaluated using a scanning electron microscope (SEM) and a focused ion beam (FIB) microscope. The evaluation results are shown in Tables 2 to 4 below.

Table 2: Metal pad cleaning effect and substrate corrosion Embodiment Operating temperature ( ^o C) Operation time (min) Cleaning effect Sidewall polymer impurities Substrate corrosion 1 40 10 Clean without residue No corrosion 2 50 10 Clean without residue No corrosion 3 70 60 Clean without residue No corrosion 4 50 60 Clean without residue No corrosion 5 60 30 Clean without residue No corrosion 6 55 50 Clean without residue No corrosion 7 75 120 Clean without residue No corrosion 8 50 5 Clean without residue No corrosion 9 40 30 Clean without residue No corrosion 10 50 20 Clean without residue No corrosion Comparative Example 1 50 20 Clean without residue Corrosion Comparative Example 2 50 20 Residue No corrosion Comparative Example 3 50 20 Residue No corrosion

Table 3: Metal line cleaning effect and substrate corrosion Embodiment Operating temperature ( ^o C) Operation time (min) Cleaning effect Sidewall polymer impurities Substrate corrosion 1 40 5 Clean without residue No corrosion 2 50 5 Clean without residue No corrosion 3 70 10 Clean without residue No corrosion 4 50 60 Clean without residue No corrosion 5 60 120 Clean without residue No corrosion 6 55 10 Clean without residue No corrosion 7 75 60 Clean without residue No corrosion 8 50 30 Clean without residue No corrosion 9 40 45 Clean without residue No corrosion 10 50 60 Clean without residue No corrosion Comparative Example 1 50 60 Clean without residue Corrosion Comparative Example 2 50 60 Residue No corrosion Comparative Example 3 50 60 Residue No corrosion

Table 4: Via cleaning effect and substrate corrosion Embodiment Operating temperature ( ^o C) Operation time (min) Cleaning effect Sidewall polymer impurities Substrate corrosion 1 40 20 Clean without residue No corrosion 2 50 20 Clean without residue No corrosion 3 70 120 Clean without residue No corrosion 4 50 30 Clean without residue No corrosion 5 60 10 Clean without residue No corrosion 6 55 30 Clean without residue No corrosion 7 75 90 Clean without residue No corrosion 8 50 75 Clean without residue No corrosion 9 40 20 Clean without residue No corrosion 10 50 10 Clean without residue No corrosion Comparative Example 1 50 10 Clean without residue Corrosion Comparative Example 2 50 10 Residue No corrosion Comparative Example 3 50 10 Residue No corrosion

The polymer impurities on the sidewalls are more difficult to remove than the polymer impurities on the substrate. If the polymer impurities on the sidewalls can be removed, it means that the impurities on the patterned wafer after etching and ashing have been completely removed. From the results in Tables 2 to 4, it can be seen that the semi-aqueous wafer substrate cleaning liquid composition of the present invention can effectively remove the polymer impurities on the sidewalls of the metal pads, metal wires, and through holes of the patterned wafer after etching and ashing, and does not corrode the substrate material, and has substantial characteristics such as a wide range of implementation and a large operating window.

It is worth noting that, compared with Example 10, Comparative Example 1 does not add γ-butyrolactone. Although it can remove the side wall polymer impurities, it seriously corrodes the base material; Comparative Example 2 does not contain organic alcohol amine and cannot effectively remove the side wall polymer impurities; Comparative Example 3 does not contain water and cannot effectively remove the base polymer impurities.

In summary, the semi-aqueous wafer substrate cleaning liquid composition of the present invention does not contain non-hydroxylamine, has good stability, has excellent cleaning effect on sidewall polymer impurities, does not corrode the substrate, and has substantial characteristics such as a wide implementation range and a large operating window.

The above is to illustrate the implementation of the present invention through specific embodiments. Those with ordinary knowledge in the relevant technical field can easily understand other advantages and effects of the present invention from the contents disclosed in this specification. The preferred embodiments of the present invention are not used to limit the scope of the present invention; any other equivalent changes or modifications that are completed without departing from the spirit disclosed by the present invention should be included in the following patent scope.

Claims (10)

A semi-aqueous wafer substrate cleaning liquid composition comprises: organic alcohol amine, polar organic solvent, γ-butyrolactone, buffer and water, wherein the weight ratio of the organic alcohol amine, γ-butyrolactone and water is 1-80:30-2:40-1. The semi-aqueous wafer substrate cleaning liquid composition as described in claim 1, wherein the weight ratio of the organic alcohol amine, γ-butyrolactone and water is 2-50:20-5:30-5. A semi-aqueous wafer substrate cleaning liquid composition as described in claim 1, wherein the organic alcohol amine is selected from at least one of monoethanolamine, N,N-dimethylethanolamine, N,N-diethylethanolamine, isopropanolamine, diisopropanolamine, triisopropanolamine, diethanolamine, triethanolamine, 3-propanolamine, 2-aminoethanolamine, ethyldiethanolamine, N-(2-aminoethyl)ethanolamine and diglycolamine. The semi-aqueous wafer substrate cleaning liquid composition as described in claim 1, wherein the polar organic solvent is selected from at least one of formamide, N-methylformamide, N-methylacetamide, N,N-dimethylformamide, N,N-dimethylacetamide, dimethyl sulfoxide, tetrahydrothiophene sulfone (cyclobutane sulfone), acetonitrile, benzonitrile, N-methyl-pyrrolidone, N-ethyl-pyrrolidone, 1-cyclohexyl-2-pyrrolidone, diethylene glycol monomethyl ether, diethylene glycol monoethyl ether, diethylene glycol monobutyl ether, dipropylene glycol monomethyl ether, dipropylene glycol monoethyl ether, dipropylene glycol monobutyl ether, diethylene glycol dimethyl ether, diethylene glycol dimethyl ether, triethylene glycol dimethyl ether, tetraethylene glycol dimethyl ether, hexamethylenetetramine and propylene carbonate. The semi-aqueous wafer substrate cleaning liquid composition as described in claim 1, wherein the buffer is selected from at least one of phenol and its derivative compounds. The semi-aqueous wafer substrate cleaning liquid composition as described in claim 1, wherein the buffer is selected from at least one of phenol, 4-methylphenol, 3,4-dicarboxyphenol, o-catechol, resorcinol, hydroquinone, 3-methyl o-catechol, 4-methyl o-catechol, 3-carboxy o-catechol, 4-carboxy o-catechol, dimethyl o-catechol, 3-tert-butyl o-catechol, 4-tert-butyl o-catechol, o-catechol acetate, trihydroxybenzene, gallic acid, methyl gallate, ethyl gallate, n-propyl gallate, isopropyl gallate, and n-butyl gallate. A method for using a semi-aqueous wafer substrate cleaning liquid composition comprises: Providing a patterned wafer after etching and removing photoresist, which has polymer impurities; Soaking or spraying the patterned wafer with the semi-aqueous wafer substrate cleaning liquid composition of any one of claims 1 to 6 to remove the polymer impurities; and Cleaning the patterned wafer with deionized water after removing the polymer impurities. A method for using a semi-aqueous wafer substrate cleaning liquid composition as described in claim 7, wherein the patterned wafer is formed with at least one of a metal pad, a metal wire, and a through hole. The method for using the semi-aqueous wafer substrate cleaning liquid composition as described in claim 7, wherein the temperature for removing the polymer impurities using the semi-aqueous wafer substrate cleaning liquid composition is between 40-75 ^° C. A method for using the semi-aqueous wafer substrate cleaning liquid composition as described in claim 7, wherein the time for removing the polymer impurities using the semi-aqueous wafer substrate cleaning liquid composition is between 10 and 120 minutes.