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

Abstract

The present invention provides a semi-aqueous wafer substrate cleaning liquid composition comprising: an organic alcohol amine, a polar organic solvent, γ-butyrolactone, a corrosion inhibitor and water, wherein the weight ratio of the organic alcohol amine, the polar organic solvent, γ-butyrolactone, the corrosion inhibitor and the water is 10-50%: 10-55%: 5-20%: 5-15%: 5-30%. The present invention also provides a method for using the semi-aqueous wafer substrate cleaning liquid composition, comprising: providing a patterned wafer after etching to remove 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 polymer impurities; and washing the patterned wafer after removing the polymer impurities with deionized water.

Description

Technical Field

[0001] The invention relates to the technical field of wet electronic chemicals for semiconductor wafer manufacturing process, and in particular to a semi-aqueous wafer substrate cleaning liquid composition suitable for stripping and removing photoresist, photoresist residue and etching residue on a wafer and a use method thereof. Background Art

[0002] 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 chip substrate, and then use the photoresist as a mask to form a circuit pattern. After baking and development, the resulting pattern is then transferred to the underlying substrate material (electrolyte or metal layer) via 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 sidewalls or around the etching substrate, and the photoresist shielding material will also be cross-linked, making it more difficult to remove.

[0003] After etching is completed, the photoresist mask and etching residues must be removed from the pattern wafer in order to proceed to the next step. Currently, the mainstream Al or Al (Cu) metallized substrate cleaning step after etching and removing the photoresist mask (ashing) uses hydroxylamine cleaning liquid. The advantage of hydroxylamine cleaning liquid is that it can effectively remove various insoluble inorganic residues and organic residues. However, the operating temperature of hydroxylamine cleaning agents is usually above 65°C, and hydroxylamine is very unstable and has the risk of explosion at higher operating temperatures. At the same time, higher operating temperatures will cause rapid decomposition of system components and volatilization of water, making the tank life of hydroxylamine cleaning liquids usually only about 1000 minutes, and continuous replenishment is required to maintain the tank life.

[0004] In addition, after the etching and ashing of the patterned wafer, 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.

[0005] In view of 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 large operating window. Summary of the invention

[0006] 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, polysilicon, etc.

[0007] The semi-aqueous wafer substrate cleaning liquid composition of the present invention comprises organic alcohol amine, polar organic solvent, gamma-butyrolactone, corrosion inhibitor and water, wherein the weight ratio of the organic alcohol amine, gamma-butyrolactone and water is 1-80:30-2:40-1.

[0008] The method for using the semi-aqueous wafer substrate cleaning liquid composition of the present invention comprises: providing a patterned wafer after etching to remove 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 with deionized water after removing the polymer impurities.

[0009] 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 sidewall polymer impurities remaining on patterned wafers after etching and ashing, and at the same time will not corrode the substrate material, and has substantial characteristics such as a large implementation range and a large operating window.

[0010] In order to make those skilled in the art understand the purpose, characteristics and effects of the present invention, the present invention is described in detail through the following specific embodiments. DETAILED DESCRIPTION

[0011] The following is a more detailed description of the embodiments of the present invention so that those skilled in the art can understand the technical features and effects of the present invention after reading this specification.

[0012] The terms used herein are only used to illustrate 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 shield in the semiconductor lithography process.

[0013] The semi-aqueous wafer substrate cleaning liquid composition of the present invention comprises an organic alcohol amine, a polar organic solvent, γ-butyrolactone, a corrosion inhibitor 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 corrosion inhibitor may be between 1-20%, such as 2-10%; and the weight ratio of water may be between 1-40%, such as 10-30%.

[0014] Specifically, the organic alcohol amine 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 alcohol amines include monoethanolamine, diglycolamine, N-methylethanolamine and N'N-dimethylethanolamine.

[0015] 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 (cyclopentane 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.

[0016] 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 function of a corrosion inhibitor. In addition, in terms of solubility, it has good solubility for various oils and fats and is also an excellent solvent.

[0017] Specifically, the corrosion inhibitor can be selected from at least one of phenol and its derivatives. Preferred phenol and its derivatives are, for example, phenol, 4-methylphenol, 3,4-dicarboxyphenol, catechol, resorcinol, hydroquinone, 3-methylcatechol, 4-methylcatechol, 3-carboxycatechol, 4-carboxycatechol, dimethylcatechol, 3-tert-butylcatechol, 4-tert-butylcatechol, catechol acetate, trihydroxybenzene, gallic acid, methyl gallate, ethyl gallate, n-propyl gallate, isopropyl gallate, and n-butyl gallate.

[0018] To prepare the semi-aqueous wafer substrate cleaning liquid composition of the present invention, it is only necessary to add the above components into pure water in sequence and stir to dissolve. During the dissolution process, the heat release of the organic base must be controlled, and the temperature of the entire dissolution process is controlled below 50 degrees. After complete dissolution, it can be filtered with a filter element below 0.1μm.

[0019] Specifically, the patterned wafer is formed with at least one of a metal pad, a metal line, and a via.

[0020] Specifically, the temperature for removing polymer impurities with the semi-aqueous wafer substrate cleaning fluid composition is between 40° C. and 75° C.

[0021] Specifically, the time for removing polymer impurities using the semi-aqueous wafer substrate cleaning liquid composition is between 10 and 120 minutes.

[0022] 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.

[0023] In order to enable those skilled in the art who are familiar with the present invention to further understand the present invention and implement it accordingly, the present invention is described in detail through the following specific embodiments.

[0024] The compositions of the embodiments and comparative examples are shown in Table 1 below.

[0025] Table 1

[0026]

[0027]

[0028]

[0029] 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 10cm*10cm small pieces of samples. 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 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.

[0030] Table 2: Cleaning effect of metal pad and substrate corrosion

[0031]

[0032]

[0033] Table 3: Metal line cleaning effect and substrate corrosion

[0034]

[0035]

[0036] Table 4: Via cleaning effect and substrate corrosion

[0037]

[0038] 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 large implementation range and a large operating window.

[0039] It is worth noting that compared with Example 10, Comparative Example 1 does not add γ-butyrolactone. Although it can remove side wall polymer impurities, it seriously corrodes the substrate material; Comparative Example 2 does not contain organic alcohol amine and cannot effectively remove side wall polymer impurities; Comparative Example 3 does not contain water and cannot effectively remove substrate polymer impurities.

[0040] 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 large implementation range and a large operating window.

[0041] The above describes the implementation of the present invention through specific embodiments. Those skilled in the art 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 intended to limit the scope of the present invention; any other equivalent changes or modifications that do not deviate from the spirit disclosed by the present invention should be included in the scope of the claims.

Claims

1. A semi-aqueous wafer substrate cleaning liquid composition, characterized in that: The invention is composed of the following components: organic alcohol amine, polar organic solvent, γ-butyrolactone, corrosion inhibitor and water, wherein the weight percentage of the organic alcohol amine, polar organic solvent, γ-butyrolactone, corrosion inhibitor and water is 10-50%, 10-55%, 5-20%, 5-15% and 5-30%, 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, 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, and The corrosion inhibitor is selected from at least one of phenol and its derivatives.

2. The semi-aqueous wafer substrate cleaning liquid composition according to claim 1, characterized in that: The weight percentages of the organic alcohol amine, polar organic solvent, gamma-butyrolactone, corrosion inhibitor and water are 10-50%, 30-50%, 5-15%, 5-10% and 10-30%.

3. The semi-aqueous wafer substrate cleaning liquid composition according to claim 1, characterized in that: 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.

4. The semi-aqueous wafer substrate cleaning liquid composition according to claim 1, characterized in that: The corrosion inhibitor is selected from at least one of phenol, 4-methylphenol, 3,4-dicarboxylic acid phenol, catechol, resorcinol, hydroquinone, 3-methylcatechol, 4-methylcatechol, 3-carboxycatechol, 4-carboxycatechol, dimethylcatechol, 3-tert-butylcatechol, 4-tert-butylcatechol, catechol acetate, trihydroxybenzene, gallic acid, methyl gallate, ethyl gallate, n-propyl gallate, isopropyl gallate, and n-butyl gallate.

5. A method for using a semi-aqueous wafer substrate cleaning liquid composition, characterized in that: Include: Providing a patterned wafer after etching away the photoresist, which has polymer impurities; Soaking or spraying the patterned wafer with the semi-aqueous wafer substrate cleaning liquid composition according to any one of claims 1 to 4 to remove the polymer impurities; and The patterned wafer is cleaned with deionized water to remove the polymer impurities.

6. The method for using the semi-aqueous wafer substrate cleaning liquid composition as claimed in claim 5, characterized in that: The patterned wafer is formed with at least one of a metal pad, a metal line and a through hole.

7. The method for using the semi-aqueous wafer substrate cleaning liquid composition as claimed in claim 5, characterized in that: The operating temperature for removing the polymer impurities by using the semi-aqueous wafer substrate cleaning liquid composition is between 40-75°C.

8. The method for using the semi-aqueous wafer substrate cleaning liquid composition as claimed in claim 5, characterized in that: The time for removing the polymer impurities by using the semi-aqueous wafer substrate cleaning liquid composition is between 10 and 120 minutes.

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