Low-corrosion and easy-to-clean chip photoresist stripping liquid as well as preparation method and application thereof

Abstract

The invention provides a low-corrosion and easy-to-clean chip photoresist stripping liquid as well as a preparation method and application thereof. The low-corrosion and easy-to-clean chip photoresist stripping liquid comprises the following components in parts by weight: 5-20 parts of an amine compound; 60 to 80 parts of an amide solvent; 1-10 parts of a hydroxyphenethyl alcohol compound; and 0.5 to 1 part of (2-(benzodihydropyran-4-yl) thiazole-4-yl) methanol. The invention further provides a preparation method of the low-corrosion and easy-to-clean chip photoresist stripping liquid and application of the low-corrosion and easy-to-clean chip photoresist stripping liquid in the field of semiconductor chip cleaning. The low-corrosion and easy-to-clean chip photoresist stripping liquid disclosed by the invention is high in photoresist removal capacity, high in selectivity, low in corrosion to a chip material and easy to clean, and has a very good application prospect and large-scale industrial popularization potential in the field of semiconductor chip cleaning.

Description

Technical Field

[0001] The invention relates to chip photoresist stripping solution technology, and in particular to a low-corrosion, easy-to-clean chip photoresist stripping solution, and a preparation method and application thereof. Background Art

[0002] In the process of manufacturing semiconductor components, a photoresist mask is formed on the surface of some materials, and the pattern is transferred after exposure. After obtaining the required pattern, the residual photoresist needs to be removed before the next process. The selection and use of photoresist stripping liquid directly affects the quality and efficiency of chip manufacturing.

[0003] At present, the photoresist cleaning solution is mainly composed of polar organic solvents, strong alkaline compounds and / or water, surfactants, buffers, other additives, etc. The photoresist on the semiconductor wafer is removed by immersing the semiconductor wafer in the cleaning solution or rinsing the semiconductor wafer with the cleaning solution.

[0004] However, existing photoresist stripping solutions may encounter some problems during use. First, the removal effect is poor. Sometimes the photoresist stripping solution cannot completely remove the photoresist, resulting in photoresist residues remaining on the chip surface, affecting subsequent process steps or device performance. Second, the impact on chip materials. Some photoresist stripping solutions may be corrosive to chip materials, which may cause device damage or performance degradation.

[0005] Therefore, in order to overcome the problems of insufficient cleaning ability and corrosion to metals caused by existing photoresist cleaning solutions, it is urgent to develop a low-corrosion and easy-to-clean chip photoresist stripping solution. Summary of the invention

[0006] The purpose of the present invention is to propose a low-corrosion, easy-to-clean chip photoresist stripping solution to address the problems of insufficient cleaning ability and corrosion to metals in existing chip photoresist cleaning solutions. The photoresist stripping solution has strong photoresist removal ability and high selectivity, low corrosion to chip materials, and is easy to clean. It has very good application prospects and large-scale industrial promotion potential in the field of semiconductor chip cleaning.

[0007] It should be noted that, in the present invention, unless otherwise specified, the specific meaning of "including" in relation to composition limitations and descriptions includes both open-ended "including", "comprising", etc. and similar meanings, as well as closed-ended "composed of", "composed of", etc. and similar meanings.

[0008] To achieve the above object, the technical solution adopted by the present invention is: a low-corrosion, easy-to-clean chip photoresist stripping solution, comprising the following components in weight proportions:

[0009] 5-20 parts of amine compounds;

[0010] 60-80 parts of amide solvent;

[0011] 1-10 parts of hydroxyphenethanol compounds;

[0012] 0.5-1 part of (2-(chroman-4-yl)thiazol-4-yl)methanol.

[0013] Furthermore, the amine compound is an aromatic diamine.

[0014] Furthermore, the aromatic diamine is one or more of o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 2,4-diaminotoluene, 2,6-diaminotoluene, 3,3'-diaminobenzidine, benzidine, 1,8-diaminonaphthalene and 4,4'-diaminotriphenylamine.

[0015] Furthermore, the amine compound is preferably 4,4'-diaminotriphenylamine.

[0016] Furthermore, the amine compound is 7-12 parts.

[0017] The amine compound selected in the present invention has strong alkalinity and can decompose the photoresist molecular chain into small molecules, thereby effectively removing the photoresist that is ashed after etching.

[0018] Furthermore, the amide solvent is one or more of N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylformamide, N-methylformamide, N-propylformamide, N,N-diethylacetamide, N-pyrrolidine-2-methyl-acetamide, N,N-diethylpyrrolidine-2-formamide, N-isopropyl-N-pyrrolidine-2-methyl-acetamide and N-ethylformamide.

[0019] Furthermore, the amide solvent is preferably N,N-dimethylformamide.

[0020] Furthermore, the amide solvent is 65-75 parts.

[0021] Furthermore, the hydroxyphenylethanol compound is one or more of 3,4-dihydroxyphenylethanol, 3,4-dihydroxyphenylethylene glycol, 4-(2-hydroxypropyl)benzene-1,2-diol and 3,4,5-trihydroxyphenylethanol.

[0022] Furthermore, the hydroxyphenethanol compound is preferably 3,4,5-trihydroxyphenethanol.

[0023] The structural formula of the 3,4-dihydroxyphenylethanol is as follows:

[0024]

[0025] The structural formula of the 3,4-dihydroxyphenyl glycol is as follows:

[0026]

[0027] The structural formula of the 4-(2-hydroxypropyl)benzene-1,2-diol is as follows:

[0028]

[0029] The structural formula of the 3,4,5-trihydroxyphenylethanol is as follows:

[0030]

[0031] Furthermore, the hydroxyphenethanol compound is 5-8 parts.

[0032] The advantages of the hydroxyphenethanol selected by the present invention are: the hydroxyphenethanol compounds provide phenolic hydroxyl groups as hydrogen donors, which have a scavenging effect on various active oxygen species, can reduce singlet oxygen to triplet oxygen with lower activity, and reduce the possibility of oxygen free radical generation; on the other hand, the hydroxyphenethanol compounds can also scavenge various free radicals by reacting with dissolved oxygen O2 to generate polyphenol free radicals with lower activity, thereby interrupting the chain reaction of free radical oxidation; in addition, the ortho-phenolic hydroxyl groups of the hydroxyphenethanol compounds can chelate metal ions, reducing the chance of metal ion catalyzing oxidation reactions. The hydroxyphenethanol compounds are amphiphilic, making them both soluble in water and soluble in oily substances. This property makes it easier for the stripping liquid to contact the grooves and gaps on the chip surface, further reducing residues and improving cleaning ability.

[0033] Furthermore, the (2-(chroman-4-yl)thiazol-4-yl)methanol is 0.5-0.7 parts.

[0034] Furthermore, the mass ratio of the (2-(chroman-4-yl)thiazol-4-yl)methanol to the hydroxyphenylethanol compound is 1:1-20.

[0035] Furthermore, the mass ratio of the (2-(chroman-4-yl)thiazol-4-yl)methanol to the hydroxyphenylethanol compound is preferably 1:10.

[0036] The molecular formula of (2-(chroman-4-yl)thiazol-4-yl)methanol is C 13 H 13 NO2S, the structural formula is as follows:

[0037]

[0038] The advantage of selecting (2-(chroman-4-yl)thiazol-4-yl)methanol in the present invention is that: (2-(chroman-4-yl)thiazol-4-yl)methanol, on the one hand, contains O, S, and N atoms in the molecule, wherein the lone pair of electrons can form a coordination bond with the 2p orbit of the metal atom to generate chemical adsorption, thereby preventing the corrosive medium from contacting the metal surface; on the other hand, the large π bond in the benzene ring and the heterocyclic ring can also form a coordination bond with the 2p orbit of the metal atom, thereby further enhancing the chemical adsorption.

[0039] Another object of the present invention is to disclose a method for preparing a low-corrosion, easy-to-clean chip photoresist stripping solution, comprising the following steps:

[0040] Step 1: Weigh each component separately;

[0041] Step 2: Evenly mix the amine compound and the amide solvent, add the hydroxyphenylethanol compound and mix evenly, add (2-(benzodihydropyran-4-yl)thiazol-4-yl)methanol and mix evenly to prepare a low-corrosion, easy-to-clean chip photoresist stripping solution.

[0042] Another object of the present invention is to disclose the use of a low-corrosion, easy-to-clean chip photoresist stripping solution in the field of cleaning semiconductor chips.

[0043] Furthermore, the semiconductor chip is cleaned by using the low-corrosion and easy-to-clean chip photoresist stripping solution, comprising the following steps:

[0044] Step 1: Soak the chip in a low-corrosion, easy-to-clean chip photoresist stripping solution at 80-95° C. for 10-40 minutes to obtain a soaked chip;

[0045] Step 2: Rinse the soaked chip in ultrapure water to complete the cleaning of the semiconductor chip.

[0046] Furthermore, the flushing in step 2 is performed more than or equal to twice.

[0047] Furthermore, the ultrapure water is deionized water with a resistance greater than or equal to 18 MΩ.

[0048] The low-corrosion, easy-to-clean chip photoresist stripping solution of the present invention, its preparation method and use have the following advantages compared with the prior art:

[0049] (1) The photoresist stripping solution of the present invention uses (2-(chroman-4-yl)thiazol-4-yl)methanol and hydroxyphenylethanol compounds. The (2-(chroman-4-yl)thiazol-4-yl)methanol molecule contains O, S, and N atoms, in which the lone pair of electrons can form a coordination bond with the 2p orbital of the metal atom to undergo chemical adsorption, thereby preventing the corrosive medium from contacting the metal surface; on the other hand, the large π bond in the benzene ring and the heterocyclic ring can also form a coordination bond with the 2p orbital of the metal atom, further enhancing chemical adsorption. At the same time, the hydroxyphenylethanol compound can provide a phenolic hydroxyl group with extremely high reduction activity, which has a scavenging effect on various active oxygen species, and can reduce singlet oxygen to triplet oxygen with lower activity, thereby reducing the possibility of generating oxygen free radicals.

[0050] (2) The polyphenol free radicals with low activity generated by the hydroxyphenylethanol compounds in the photoresist stripping solution of the present invention through the reaction with dissolved oxygen O2 can also remove various free radicals generated by the oxidation reaction, thereby interrupting the chain reaction of free radical oxidation; in addition, the ortho-phenolic hydroxyl groups of the hydroxyphenylethanol compounds can chelate metal ions and reduce the occurrence of metal ion-catalyzed oxidation reactions. At the same time, the hydroxyphenylethanol compounds have amphiphilicity, making them soluble in both water and oily substances. This property makes the stripping solution easier to contact the grooves and gaps on the chip surface, further reducing residues and improving cleaning ability.

[0051] (3) The amide solvent in the photoresist stripping solution of the present invention is a strong polar solvent, which can effectively swell and soften the photoresist, disentangle the molecular chains, swell the resin layer, and further accelerate the dissolution of the photoresist, so that the amine compound can contact the photoresist in a larger range and decompose the molecular chains in the photoresist into small molecules, effectively removing the photoresist that has become ashed after etching.

[0052] Therefore, the low-corrosion and easy-to-clean chip photoresist stripping solution of the present invention can be used for cleaning photoresist in semiconductor manufacturing. While improving the degumming ability, it has a good protective effect on metal electrodes such as Ag, can effectively inhibit their corrosion, and prolong their service life. It has very good application prospects and large-scale industrial promotion potential in the field of semiconductor chip cleaning. BRIEF DESCRIPTION OF THE DRAWINGS

[0053] Figure 1 This is a microscope picture of the Cu substrate chip before cleaning after 50 times magnification;

[0054] Figure 2 This is a microscope picture magnified 50 times of the Cu substrate chip after being cleaned with the photoresist stripping solution of Example 1;

[0055] Figure 3 This is a microscope picture magnified 50 times of the Cu substrate chip after cleaning with the photoresist stripping solution of Comparative Example 1;

[0056] Figure 4 This is a 500-fold magnified image of the Ag electrode chip that has not been immersed in photoresist stripping solution under a microscope;

[0057] Figure 5 This is a picture of the Ag electrode chip after being immersed in the photoresist stripping solution of Example 1, magnified 500 times under a microscope;

[0058] Figure 6 This is a picture of the Ag electrode chip after being immersed in the photoresist stripping solution of Comparative Example 1, magnified 500 times under a microscope. DETAILED DESCRIPTION

[0059] The present invention is further described below with reference to the examples. The description of the technical features described below is based on representative embodiments and specific examples of the present invention, but the present invention is not limited to these embodiments and specific examples. It should be noted that:

[0060] Unless otherwise stated, the units used in this specification are all international standard units, and the numerical values ​​and numerical ranges appearing in the present invention should be understood to include the inevitable systematic errors in industrial production.

[0061] In this specification, the numerical range expressed using "a numerical value A to a numerical value B" means a range including the endpoints numerical values ​​A and B.

[0062] In the present specification, a numerical range expressed using "above" or "below" means a numerical range including the number.

[0063] In this specification, the word "may" includes both performing a certain process and not performing a certain process.

[0064] In this specification, the use of "optional" or "optional" indicates that certain substances, components, execution steps, application conditions and other factors are used or not used.

[0065] In this specification, when "normal temperature" or "room temperature" is used, the temperature may be 15-25°C.

[0066] In this manual, the reagents or instruments used without indicating the manufacturer are all conventional products that can be obtained through commercial purchase.

[0067] Examples 1-10

[0068] Examples 1-10 disclose a variety of low-corrosion, easy-to-clean chip photoresist stripping solutions, the components and weight ratios of which are shown in Table 1.

[0069] The method for preparing the low-corrosion and easy-to-clean chip photoresist stripping solution comprises the following steps:

[0070] Step 1: Weigh each component in its respective amount;

[0071] Step 2: After the amine compound and the amide solvent are stirred evenly, a hydroxyphenylethanol compound is added, and after stirring evenly, (2-(benzodihydropyran-4-yl)thiazol-4-yl)methanol is added, and after stirring evenly, a low-corrosion, easy-to-clean chip photoresist stripping solution is prepared.

[0072] Table 1 Components and weight ratios of photoresist stripping solutions in Examples 1-10

[0073]

[0074]

[0075] Comparative Examples 1-3

[0076] Comparative Examples 1-3 disclose a variety of photoresist stripping solutions, the components and weight ratios of which are shown in Table 2, and the preparation methods thereof are the same as those of Example 1.

[0077] Table 2 Components and weight ratios of photoresist stripping solutions of Comparative Examples 1-3

[0078]

[0079]

[0080] The photoresist stripping solutions of the above embodiments or comparative examples were tested as follows.

[0081] Performance 1 The test method for cleaning effect is:

[0082] Step 1: Immerse a Cu substrate chip coated with a 100 μm thick negative photoresist in a photoresist stripping solution at 85° C. for 10 minutes to obtain an immersed chip;

[0083] Step 2: Rinse the soaked chip twice in ultrapure water to complete the chip cleaning process. Use SEM to observe the chip cleaning effect. The test results are shown in Figure 2-3 .

[0084] The ultrapure water used in step 2 is deionized water with a resistance of at least 18 MΩ.

[0085] Performance 2 The test method for metal corrosion is:

[0086] The four-probe method was used to test the corrosion performance of different photoresist stripping solutions on metal Ag.

[0087] The specific test method is: immerse a 2cm×2cm Ag sheet in 85°C photoresist stripping solution for 60 minutes.

[0088] Then the four-probe method was used to measure the thickness of the Ag film before and after immersion in the photoresist stripping solution, and the respective corrosion rates ( Right now It can also be called "etching rate"), thereby investigating the corrosion rate of different photoresist stripping solutions on metals. The test results are shown in Figure 5-6 and Table 3.

[0089] Table 3 Test data

[0090]

[0091]

[0092] Based on Table 3, it can be seen that the Ag corrosion rate of the photoresist stripping solution of the embodiment of the present invention at a stripping temperature of 85°C is

[0093] In Comparative Examples 1-3, the metal corrosion rate at the degumming temperature of 85°C is

[0094] It can be seen that the photoresist stripping solution provided in the embodiment of the present invention has a good protective effect on the photoresist and the Ag metal electrode, and can effectively inhibit the corrosion of the Ag metal.

[0095] From the comparison between Examples 1-10 of the present invention and Comparative Examples 1-3, it can be seen that when hydroxyphenylethanol compounds and (2-(chroman-4-yl)thiazol-4-yl)methanol are simultaneously present in the photoresist stripping solution, the two can exert a synergistic effect, thereby achieving an excellent anti-corrosion effect;

[0096] Comparative Example 1 uses ethylene glycol without adding hydroxyphenylethanol compounds, which results in an increase in the metal corrosion rate;

[0097] Comparative Example 2 did not add hydroxyphenylethanol compounds, and its corrosion rate was similar to that of Comparative Example 1, but its photoresist stripping ability was lower than that of Comparative Example 1, and more residual glue appeared. Compared with Example 1, the metal corrosion rate increased;

[0098] Comparative Example 3 did not add (2-(chroman-4-yl)thiazol-4-yl)methanol, resulting in an increase in the metal corrosion rate.

[0099] Description of the attached drawings:

[0100] Figure 1 This is a microscope picture of the Cu substrate chip before cleaning after 50 times magnification; Figure 2 This is a microscope picture magnified 50 times of the Cu substrate chip after being cleaned with the photoresist stripping solution of Example 1; Figure 3This is a microscope picture of the Cu substrate chip after cleaning with the photoresist stripping solution of Comparative Example 1, magnified 50 times; Figure 1-3 It can be seen that there is no residual glue on the Cu substrate chip after being cleaned with the chip photoresist stripping solution of Example 1 of the present invention.

[0101] Figure 4 This is a 500-fold magnified image of the Ag electrode chip that has not been immersed in photoresist stripping solution under a microscope; Figure 5 This is a picture of the Ag electrode chip after being immersed in the photoresist stripping solution of Example 1, magnified 500 times under a microscope; Figure 6 This is a 500-fold magnified image of the Ag electrode chip after being treated with the photoresist stripping solution of Comparative Example 1. Figure 4-6 It can be seen that Figure 6 The appearance of corrosion bright spots proves that the Ag electrode chip has been corroded after being cleaned with the chip photoresist stripping solution of Comparative Example 1.

[0102] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it. Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art should understand that they can still modify the technical solutions described in the aforementioned embodiments, or replace some or all of the technical features therein with equivalents. However, these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A low-corrosion, easy-to-clean chip photoresist stripping solution, characterized in that: The composition includes the following components in weight ratio: 5-20 parts of amine compounds; 60-80 parts of amide solvent; 1-10 parts of hydroxyphenethanol compounds; 0.5-1 part of (2-(chroman-4-yl)thiazol-4-yl)methanol.

2. The low-corrosion, easy-to-clean chip photoresist stripping solution according to claim 1, characterized in that: The amine compound is an aromatic diamine.

3. The low-corrosion, easy-to-clean chip photoresist stripping solution according to claim 2, characterized in that: The aromatic diamine is one or more of o-phenylenediamine, m-phenylenediamine, p-phenylenediamine, 2,4-diaminotoluene, 2,6-diaminotoluene, 3,3'-diaminobenzidine, benzidine, 1,8-diaminonaphthalene and 4,4'-diaminotriphenylamine.

4. The low-corrosion, easy-to-clean chip photoresist stripping solution according to claim 1, characterized in that: The amide solvent is one or more of N,N-dimethylformamide, N,N-dimethylacetamide, N,N-diethylformamide, N-methylformamide, N-propylformamide, N,N-diethylacetamide, N-pyrrolidine-2-methyl-acetamide, N,N-diethylpyrrolidine-2-formamide, N-isopropyl-N-pyrrolidine-2-methyl-acetamide and N-ethylformamide.

5. The low-corrosion, easy-to-clean chip photoresist stripping solution according to claim 1, characterized in that: The hydroxyphenylethanol compound is one or more of 3,4-dihydroxyphenylethanol, 3,4-dihydroxyphenylethylene glycol, 4-(2-hydroxypropyl)benzene-1,2-diol and 3,4,5-trihydroxyphenylethanol.

6. The low-corrosion, easy-to-clean chip photoresist stripping solution according to claim 1, characterized in that: The mass ratio of the (2-(chroman-4-yl)thiazol-4-yl)methanol to the hydroxyphenylethanol compound is 1:1-20.

7. A method for preparing the low-corrosion, easy-to-clean chip photoresist stripping solution according to any one of claims 1 to 6, characterized in that: The steps include: Step 1: Weigh each component separately; Step 2: Evenly mix the amine compound and the amide solvent, add the hydroxyphenylethanol compound and mix evenly, add (2-(benzodihydropyran-4-yl)thiazol-4-yl)methanol and mix evenly to prepare a low-corrosion, easy-to-clean chip photoresist stripping solution.

8. Use of the low-corrosion, easy-to-clean chip photoresist stripping solution according to any one of claims 1 to 6 in the field of cleaning semiconductor chips.

9. The use according to claim 8, characterized in that: The method of using the low-corrosion and easy-to-clean chip photoresist stripping solution to clean a semiconductor chip comprises the following steps: Step 1: Soak the chip in a low-corrosion, easy-to-clean chip photoresist stripping solution at 80-95° C. for 10-40 minutes to obtain a soaked chip; Step 2: Rinse the soaked chip in ultrapure water to complete the cleaning of the semiconductor chip.

10. The use according to claim 9, characterized in that: The flushing in step 2 is performed twice or more.

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