A cleaning solution suitable for removing positive and negative photoresists

Abstract

The invention provides a cleaning solution for removing photoresist residues, which contains quaternary ammonium hydroxide, alcohol amine, alcohol solvent, silane, hydrazine and its derivatives, water, and the balance is an organic solvent. The cleaning solution effectively removes the photoresist residues on the wafer and has no corrosion to the substrate such as metal aluminum, copper, etc., and has good application prospects in the fields of semiconductor wafer cleaning.

Description

Technical Field

[0001] The invention relates to the technical field of cleaning liquids, and in particular to a cleaning liquid for removing photoresist residues. Background Art

[0002] In the semiconductor manufacturing process, by forming a mask of photoresist on the surface of some materials, pattern transfer is performed after exposure, and after obtaining the required pattern, the remaining photoresist needs to be stripped off before the next step. In this process, it is required to completely remove unnecessary photoresist and not to corrode any substrate.

[0003] 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 rinsing the semiconductor wafer with the cleaning solution.

[0004] JP1998239865 discloses a cleaning solution containing an aqueous system, which is composed of tetramethylammonium hydroxide (TMAH), dimethyl sulfoxide (DMSO), 1,3'-dimethyl-2-imidazolidinone (DMI) and water. The wafer is immersed in the cleaning solution to remove photoresists of more than 20 μm on metal and dielectric substrates at 50-100° C. The corrosion of the semiconductor wafer substrate is slightly higher, and the photoresist on the semiconductor wafer cannot be completely removed, and the cleaning ability is insufficient.

[0005] US5529887 discloses an alkaline cleaning solution composed of potassium hydroxide (KOH), alkyldiol monoalkyl ether, water-soluble fluoride and water, and the like, so that the wafer is immersed in the cleaning solution, and the photoresist on the metal and dielectric substrate are removed at 40 to 90°C. It has high corrosion on semiconductor wafer substrates.

[0006] US5480585 discloses a cleaning solution containing a non-aqueous system, which consists of ethanolamine, sulfolane or dimethylsulfoxide and catechol, which can remove photoresist on metals and dielectric substrates at 40 to 120°C, and is basically free from corrosion to metals.

[0007] US 2005119142 discloses a non-aqueous cleaning solution of a polymer containing an alkoxy group, a dipropylene glycol alkyl ether, N-methylpyrrolidone and methyl isobutyl ketone. The cleaning solution can be used for both positive photoresist and negative photoresist cleaning.

[0008] With the rapid development of semiconductors, especially in the field of convex ball packaging, the cleaning requirements for photoresist residues have also been increased accordingly; mainly because the number of pins (I / O) per unit area is increasing, and the removal of photoresist is becoming increasingly difficult.

[0009] It can be seen from this that finding effective cleaning liquids that can remove both positive photoresist and negative photoresist is the priority direction for the efforts of this type of photoresist cleaning liquid. In order to adapt to the new situation, it is necessary to develop a cleaning solution with strong removal capabilities of positive and negative photoresist and low metal corrosion rate. Summary of the invention

[0010] It is an object of the present invention to provide a cleaning solution capable of effectively removing photoresist residues. This cleaning solution effectively removes photoresist residues on the wafer. The synergistic effect of alcohol solvents and hydrazine and its derivatives is conducive to the removal of wafer positive photoresist. It can also have a good corrosion inhibition effect on metal aluminum and metal copper, and has good application prospects in semiconductor wafer cleaning and other fields.

[0011] The novel cleaning solution contains: (a) quaternary ammonium hydroxide; (b) alcohol amine; (c) alcohol solvent; (d) silane; (e) hydrazine and its derivatives; (f) water; and (g) the balance is organic solvent.

[0012] i. quaternary ammonium hydroxide 0.1-6%;

[0013] ii. 0.1-50wt% of alcohol amine, preferably 5-40wt%;

[0014] iii. Alcohol solvent 0.1-25wt%; more preferably, 3-20wt%;

[0015] iv. silane 0.1-8wt%, more preferably, 0.5-5wt%;

[0016] v. 0.05-5wt% of hydrazine and its derivatives, preferably 0.1-3wt%;

[0017] vi. Deionized water 0.1-10wt%, preferably 0.5-6wt%;

[0018] vii. The balance is organic solvent.

[0019] In the present invention, the quaternary amine hydroxide is one or more selected from the group consisting of tetramethyl ammonium hydroxide, tetraethyl ammonium hydroxide, tetrapropyl ammonium hydroxide, tetrabutyammonium hydroxide, cetyltrimethyl ammonium hydroxide and benzyltrimethyl ammonium hydroxide.

[0020] In the present invention, alcohol amines are monoethanolamine, N-methylethanolamine, diethanolamine, triethanolamine, isopropanolamine, ethyldiethanolamine, N,N-diethylethanolamine, N-(2-aminoethyl)ethanolamine and diethylene glycolamine. Monoethanolamine, triethanolamine and mixtures thereof are preferred.

[0021] In the present invention, the alcohol solvent is selected from one or more of benzyl alcohol, ethylene glycol, propylene glycol, glycerol, 1,2-propylene glycol, tetrahydrofurfuryl alcohol, cyclohexanol, dipropylene glycol, diethylene glycol, 1,2-butanediol, 3-methoxybutanol, 1-phenoxy-2-propanol, and 1,3-butanediol.

[0022] In the present invention, the silane is one or more of tetramethoxysilane, tetraethoxysilane, trimethoxymethylsilane, trimethoxyethylsilane, trimethoxypropylsilane, dimethoxydimethylsilane, dimethoxydiethylsilane, triethoxymethylsilane, and (3-aminopropyl)triethoxysilane.

[0023] In the present invention, the derivatives of hydrazine and hydrazine are selected from one or more of hydrazine, 2-hydroxyethylhydrazine, benzohydrazine, salicylhydrazine, acetylhydrazine, benzenesulfonylhydrazine, benzenesulfonylhydrazine, carbohydrazine, methyl hydrazine, laurylhydrazine, tert-butyl hydrazine, hydrazine, ethyl hydrazine, hydrazine, hydrazine, methyl hydrazine, methyl hydrazine, adipic acid dihydrazine, butyryl hydrazine.

[0024] In the present invention, the organic solvent is one or more of sulfoxide, sulfone, imidazolidinone, pyrrolidone, imidazolinone, amide and alcohol ether. Preferably, the sulfoxide is one or more of dimethyl sulfoxide and methyl ethyl sulfoxide; the sulfone is one or more of methyl sulfone and cyclopentane sulfone; the imidazolidinone is one or more of 2-imidazolidinone and 1,3-dimethyl-2-imidazolidinone; the pyrrolidone is one or more of N-methylpyrrolidone and N-cyclohexylpyrrolidone; the imidazolinone is 1,3-dimethyl-2-imidazolidinone; the amide is one or more of dimethylformamide and dimethylacetamide;

[0025] The cleaning solution in the present invention can clean the photoresist residue on the wafer at 25°C to 80°C. The specific method is as follows: immerse the wafer containing the photoresist residue in the cleaning solution of the present invention, soak it at 25°C to 80°C for a suitable time, take it out and rinse it, and then blow dry with high-purity nitrogen.

[0026] The positive and progressive effects of the present invention are:

[0027] 1) The cleaning solution of the present invention effectively removes the photoresist residues on the wafer and has substantially no corrosion to the substrate such as metal aluminum, copper, etc.

[0028] 2) The synergistic effect of the alcohol solvent and hydrazine and its derivatives of the present invention can enhance the removal ability of positive photoresist; at the same time, the addition of hydrazine and its derivatives can protect metallic copper and have little corrosion to metallic copper;

[0029] 3) The cleaning liquid of the present invention has very good water resistance, which solves the problem of corrosion increase due to water absorption in the cleaning operation of the traditional cleaning liquid, and has good application prospects in the fields of semiconductor wafer cleaning and other fields.

[0030] The reagents and raw materials used in the present invention are all commercially available. The cleaning solution of the present invention can be prepared by simply mixing the above components evenly. DETAILED DESCRIPTION

[0031] The advantages of the present invention are further described below through specific examples, but the protection scope of the present invention is not limited to the following examples.

[0032] The reagents and raw materials used in the present invention are all commercially available. The cleaning solution of the present invention can be prepared by simply and evenly mixing the above components.

[0033] Prepare a cleaning solution according to the ingredients and proportions of each embodiment in Table 1, mix them evenly, and the mass percentage reaches 100%.

[0034] Table 1 Components and contents of the cleaning solution in the embodiment

[0035]

[0036]

[0037]

[0038] Table 2 Components and contents of the cleaning solution of the comparative example

[0039]

[0040]

[0041]

[0042] Effect Example

[0043] In order to further investigate the cleaning performance of such cleaning liquid, the present invention adopts the following technical means: the wafers containing photoresist residues after the convex balls have been electroplated in the wafer microsphere implantation process are immersed in the cleaning liquid and oscillated at a constant temperature oscillator at a vibration frequency of about 60 rpm for 30 to 120 minutes at 25°C to 80°C, and then dried with high-purity nitrogen after rinsing. The cleaning effect of the photoresist residues and the corrosion of the cleaning liquid on the wafer are shown in Table 3.

[0044] Table 3: Wafer cleaning conditions of some examples

[0045]

[0046] The meanings of the symbols for each corrosion condition in Table 3 are shown in Table 4.

[0047] Table 4 Meaning of symbols for various corrosion conditions

[0048] Corrosion conditions: Photoresist removal: ◎Basically no corrosion; ◎Completely remove; ○ Slightly corroded; ○A small amount of residue; △ Moderate corrosion; △More residues; ×Severe corrosion. ×A lot of residue

[0049] It can be seen from Table 3 that the cleaning liquid of the present invention has a good cleaning effect on wafers containing photoresist residues after the convex ball has been electroplating in the wafer microsphere implantation process, and has a good inhibitory effect on corrosion of metal aluminum and copper, and has a wide temperature range of use.

[0050] It can be seen from Comparative Example 4-1 and Example 4 that the alcohol solvent was not added, and all the amount of alcohol solvents not added to the solvent. Under the conditions of the same components and the same operating conditions, it was verified that the addition of alcohol solvents was conducive to the removal of wafer positive photoresist. Although there was no obvious difference between the two for corrosion of metal aluminum and copper, Comparative Example 4-1 for the removal of positive photoresist was not as good as Example 4;

[0051] Comparison between Comparative Example 4-2 and Example 4: No silane was added, and all the silane not added was added to the solvent. Under the same other components and operating conditions, it was verified that the addition of silane was beneficial to the removal of the negative photoresist on the wafer and the inhibition of metal aluminum corrosion. Although there was no significant difference in the removal effect of the two on metal copper corrosion and positive photoresist, Comparative Example 4-2 was not as good as Example 4 in removing the negative photoresist and inhibiting metal aluminum corrosion;

[0052] Comparison between Comparative Example 4-3 and Example 4: No hydrazine and its derivatives were added, and all the amount of hydrazine and its derivatives not added was added to the solvent. Under the same other components and operating conditions, it was verified that the addition of hydrazine and its derivatives was beneficial to the removal of the positive photoresist of the wafer and the inhibition of metal copper corrosion. Although no obvious difference was seen in the removal effect of the two on metal aluminum corrosion and negative photoresist, the removal of positive photoresist and the inhibition of metal copper corrosion in Comparative Example 4-3 were not as good as those in Example 4;

[0053] Comparison between Comparative Example 4-4 and Example 4: No hydrazine and its derivatives were added, and the amount of hydrazine and its derivatives not added was added to the alcohol solvent. Under the conditions of the same other components and the same operating conditions, it was verified that the addition of hydrazine and its derivatives was beneficial to the removal of the positive photoresist of the wafer and the inhibition of metal copper corrosion, and the removal of the negative photoresist of the wafer and the inhibition of metal aluminum corrosion were not affected; Comparison between Comparative Example 4-5 and Example 4: No alcohol solvent was added, and the amount not added was added to hydrazine and its derivatives. Under the conditions of the same other components and the same operating conditions, it was verified that the addition of alcohol solvent was beneficial to the removal of the positive photoresist of the wafer, and the removal of the negative photoresist and the inhibition of metal aluminum and copper corrosion were not affected. Comparative Examples 4-4 and 4-5 also verified that the synergistic effect of alcohol solvents and hydrazine and its derivatives was beneficial to the removal of the positive photoresist of the wafer.

[0054] By comparing comparative examples 15-1, 15-2, 15-3, 15-4, 15-54 with embodiment 15, it can be seen that comparative examples 4-1, 4-2, 4-3, 4-4, 4-5 and embodiment 4 exhibit the same rules.

[0055] In summary, the positive progress of the present invention is that the cleaning solution of the present invention can effectively remove photoresist residues under the same conditions; at the same time, there is basically no corrosion for substrates such as metal aluminum and copper, and it can be applied to the removal of positive wafer photoresist or negative wafer photoresist, and has good application prospects in the fields of semiconductor wafer cleaning and other fields.

[0056] It should be understood that the wt % mentioned in the present invention refers to the mass percentage.

[0057] The specific embodiments of the present invention are described in detail above, but they are only 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 made to the present invention are also within the scope of the present invention. Therefore, the equalization changes and modifications made without departing from the spirit and scope of the present invention should be included in the scope of the present invention.

Claims

1. A cleaning solution for removing photoresist residues, characterized in that: The cleaning solution is composed of quaternary ammonium hydroxide, alcohol amine, alcohol solvent, silane, hydrazine and its derivatives, water and organic solvent; The content of the silane is 0.1-8% by mass; The content of hydrazine and its derivatives is 0.05-5% by mass; The quaternary ammonium hydroxide is one or more selected from tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, hexadecyltrimethylammonium hydroxide and benzyltrimethylammonium hydroxide; The content of the quaternary ammonium hydroxide is 0.1-6% by mass; The alcohol amine is monoethanolamine, N-methylethanolamine, diethanolamine, triethanolamine, isopropanolamine, ethyldiethanolamine, N,N-diethylethanolamine, N-(2-aminoethyl)ethanolamine and diglycolamine; The content of the alcohol amine is 0.1-50% by mass; The alcohol solvent is selected from one or more of benzyl alcohol, ethylene glycol, propylene glycol, glycerol, tetrahydrofurfuryl alcohol, cyclohexanol, dipropylene glycol, diethylene glycol, 1,2-butanediol, 3-methoxybutanol, 1-phenoxy-2-propanol, and 1,3-butanediol; The content of the alcohol solvent is 0.1-25% by mass; The silane is one or more selected from tetramethoxysilane, tetraethoxysilane, trimethoxymethylsilane, trimethoxyethylsilane, trimethoxypropylsilane, dimethoxydimethylsilane, dimethoxydiethylsilane, triethoxymethylsilane and (3-aminopropyl)triethoxysilane; The hydrazine and its derivatives are selected from one or more of hydrazine, 2-hydroxyethylhydrazine, benzoylhydrazide, salicylic hydrazide, acetic hydrazide, benzenesulfonylhydrazide, carbohydrazide, methyl carbazate, lauryl hydrazide, tert-butyl carbazate, ethyl carbazate, hydrazinecarboxylic acid, methyl hydrazinedithiocarboxylate, formic hydrazide, adipic acid dihydrazide, and butyric hydrazide; The water content is 0.1-10% by mass; The organic solvent is one or more of sulfoxide, sulfone, imidazolidinone, pyrrolidone, imidazolinone and amide; The amide is one or more of dimethylformamide and dimethylacetamide.

2. The cleaning solution according to claim 1, characterized in that: The content of the alcohol amine is 5-40% by mass.

3. The cleaning solution according to claim 1, characterized in that: The content of the silane is 0.5-5% by mass.

4. The cleaning solution according to claim 1, characterized in that: The content of hydrazine and its derivatives is 0.1-3% by mass.

5. The cleaning solution according to claim 1, characterized in that: The water content is 0.5-6% by mass.

6. The cleaning solution according to claim 1, characterized in that: The sulfoxide is one or more of dimethyl sulfoxide and methyl ethyl sulfoxide; the sulfone is one or more of methyl sulfone and cyclopentane sulfone; the imidazolidinone is one or more of 2-imidazolidinone and 1,3-dimethyl-2-imidazolidinone; the pyrrolidone is one or more of N-methylpyrrolidone and N-cyclohexylpyrrolidone; and the imidazolinone is 1,3-dimethyl-2-imidazolidinone.

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