Photoresist stripping liquid and use method thereof

Abstract

The invention relates to the technical field of semiconductors, in particular to photoresist stripping liquid and a use method thereof. The cleaning agent comprises the following components in percentage by weight: 70%-90% of an aprotic polar solvent, 10%-30% of organic alkanolamine, 0.01%-1.5% of a metal inhibitor and 0.05%-0.3% of an interfacial agent, the metal inhibitor comprises at least one of a tetrazole derivative and a gallic acid derivative. The metal inhibitor comprises a tetrazole derivative and a gallic acid derivative, so that the stripping capability of the stripping liquid on photoresist can be improved while metal on a wafer is not damaged; the weight ratio of the tetrazole derivative to the gallic acid derivative is (0.5-5): 1, so that the stripping efficiency of the stripping liquid on photoresist can be improved, and the stripping of the photoresist can be completed under the conditions that the temperature is 60-90 DEG C and the time is 10-40 minutes.

Description

Technical Field

[0001] The present invention relates to the field of semiconductor technology, and in particular to a photoresist stripping solution and a method for using the same. Background Art

[0002] Photoresist removal is a key technology in semiconductor patterning processes, and photoresist strippers are crucial for determining the yield and reliability of photoresist removal and, ultimately, the patterning process. Currently, cleaning agents for removing etch residues contain one or more polar solvents and one or more organic alkanolamines. These alkanolamines can cause severe corrosion, particularly to the Al and Ag wiring during photoresist removal, particularly to vapor-deposited Ag and Al, which have poor density. Consequently, the stripper requires not only high removal performance but also stringent metal corrosion resistance.

[0003] Chinese invention patent application CN120065657A discloses a low-corrosion alkaline photoresist stripping solution, its preparation method, and its use. The solution comprises the following components in the following weight ratios: 0.1-5 parts of a metal protective agent; 5-25 parts of an organic base; 10-40 parts of a polar solvent; and 15-45 parts of ultrapure water. The metal protective agent comprises water-soluble carbon dots and an alkyl phosphate. While the solution is virtually non-corrosive to copper and its alloys, it does not investigate its corrosion resistance against less dense Ag and Al. Summary of the Invention

[0004] The first aspect of the present invention provides a photoresist stripping solution, which comprises, by weight percentage, 69-89.85% of an aprotic polar solvent, 10-30% of an organic alkanolamine, 0.01-1.5% of a metal inhibitor, and 0.05-0.3% of a surfactant; the metal inhibitor comprises at least one of a tetrazole derivative and a gallic acid derivative.

[0005] The metal inhibitors include tetrazole derivatives and gallic acid derivatives.

[0006] The weight ratio of the tetrazole derivative to the gallic acid derivative is (0.5-5):1.

[0007] Optionally, the weight ratio of the tetrazole derivative to the gallic acid derivative is (0.5-2.5):1.

[0008] Optionally, the weight ratio of the tetrazole derivative to the gallic acid derivative is (2-7):3.

[0009] Optionally, the content of the metal inhibitor in the photoresist stripping solution is 0.1-1 wt %.

[0010] The general structural formula of the tetrazole derivative is shown in Formula 1: Wherein R1 includes one of the following substituents: H, -NH2, -(CH2)nCH3, where 1≤n≤3; R2 includes one of the following substituents: -H, -NH2, -SH, -(CH2)nCH3 n NH2, -(CH2)nCH3, where 1≤n≤3.

[0011] Optionally, the tetrazole derivatives include at least one of 5-amino-1-tetrazole, 5-amino-1-methyltetrazole, 5-methyltetrazole, tetrazole-1,5-diamine, 5-mercapto-1-methyltetrazole, 1-methyl-1H-tetrazole, 5-ethyl-1H-1,2,3,4-tetrazole, and 1-(2-dimethyl-aminoethyl)-1H-5-mercapto-tetrazole.

[0012] The structure of the gallic acid derivative is shown in Structural Formula 2: That

[0013] R3 includes one of the following substituents: -H, -Na, -K, -(CH2)nCH3, 1≤n≤5.

[0014] Optionally, the gallic acid derivatives include at least one of gallic acid, sodium gallate, and gallic acid esters.

[0015] The surfactant includes at least one of polyoxyethylene type and polyether type.

[0016] The polyoxyethylene type includes at least one of fatty alcohol polyoxyethylene ether, fatty acid polyoxyethylene ester, alkylphenol polyoxyethylene ether, polyoxyethylene amide, polyoxyethylene fatty amine and Tween.

[0017] Fatty alcohol polyoxyethylene ether is preferred.

[0018] The polyether type includes at least one of isomeric alcohol polyether, trans polyether, polyether-modified silicone, glycerol polyether, and propylene glycol block polyether;

[0019] Optionally, the polyether type includes at least one of polyether-modified silicone and propylene glycol block polyether.

[0020] The organic alkanolamine includes at least one of monoethanolamine, diethanolamine, triethanolamine, 2-methylaminoethanolamine, methyldiethanolamine, isopropanolamine, diisopropanolamine and diglycolamine.

[0021] The aprotic polar solvent includes at least one of a sulfone organic solvent, N-methylpyrrolidone, and an amide organic solvent.

[0022] Optionally, the sulfone organic solvent is selected from at least one of dimethyl sulfone, phenethyl sulfone, diethyl sulfone, diphenyl sulfone, dimethyl sulfoxide, sulfolane and bisphenol S.

[0023] Optionally, the sulfone organic solvent is selected from at least one of dimethyl sulfoxide and sulfolane.

[0024] Optionally, the amide organic solvent includes at least one of N,N-dimethylformamide, N,N-dimethylacetamide, and N,N-dimethylpropionamide.

[0025] Optionally, the aprotic polar solvent includes dimethyl sulfoxide, N-methylpyrrolidone and N,N-dimethylacetamide.

[0026] Optionally, the weight ratio of dimethyl sulfoxide, N-methylpyrrolidone and N,N-dimethylacetamide is 1:(0.1-6):(0.25-4).

[0027] The second aspect of the present invention provides a method for using a photoresist stripping solution, comprising the following steps: placing a wafer containing cured photoresist in the photoresist stripping solution for cleaning; the cleaning temperature is 60-90° C. and the cleaning time is 10-40 minutes.

[0028] Optionally, the cleaning temperature is 65-80°C.

[0029] Beneficial effects

[0030] 1. Metal inhibitors include tetrazole derivatives and gallic acid derivatives, which can improve the stripping ability of the stripping solution on the photoresist without damaging the metal on the wafer.

[0031] 2. The weight ratio of tetrazole derivatives and gallic acid derivatives is (0.5-5):1, which can improve the stripping liquid

[0032] As for the stripping efficiency of the photoresist, the stripping of the photoresist can be completed at 60-90°C and 10-40 minutes.

[0033] 3. The content of the metal inhibitor in the photoresist stripping solution is 0.1-1 wt%, which can prevent the stripping solution from damaging Ag and Al.

[0034] 4. The photoresist stripping solution of the present application is easy to use.

[0035] 5. The photoresist stripping solution of this application can meet the needs of continuous wafer cleaning with little performance degradation. BRIEF DESCRIPTION OF THE DRAWINGS

[0036] Figure 1 This is a test image obtained using a 3D profilometer after the Ag-plated wafer is corroded by the stripping solution of Example 1.

[0037] Figure 2 This is a test image obtained using a 3D profilometer after the Ag-plated wafer is corroded by the stripping solution of Example 2.

[0038] Figure 3 This is a test image obtained using a 3D profilometer after the Ag-plated wafer is corroded by the stripping solution of Example 3.

[0039] Figure 4 This is a test image obtained using a 3D profilometer after the Ag-plated wafer is corroded by the stripping solution of Example 4.

[0040] Figure 5 This is a test image obtained using a 3D profilometer after the Ag-plated wafer is corroded by the stripping solution of Example 5.

[0041] Figure 6 This is a test image obtained using a 3D profilometer after the Ag-plated wafer is corroded by the stripping solution of Example 6.

[0042] Figure 7 This is a test image obtained using a 3D profilometer after the Ag-plated wafer is corroded by the stripping solution of Example 7.

[0043] Figure 8 This is a test image obtained using a 3D profilometer after the Ag-plated wafer is corroded by the stripping solution of Comparative Example 1.

[0044] Figure 9 This is a test image obtained using a 3D profilometer after the Ag-plated wafer is corroded by the stripping solution of Comparative Example 2.

[0045] Figure 10 This is a test image obtained using a 3D profilometer after the Ag-plated wafer is corroded by the stripping solution of Comparative Example 3.

[0046] Figure 11 This is a test image obtained using a 3D profilometer after the Ag-plated wafer is corroded by the stripping solution of Comparative Example 4.

[0047] Figure 12 This is a test image obtained using a 3D profilometer after the Ag-plated wafer is corroded by the stripping solution of Comparative Example 5.

[0048] Figure 13 This is a test image obtained using a 3D profilometer after the Al-plated wafer is corroded by the stripping solution of Example 1.

[0049] Figure 14 This is a test image obtained using a 3D profilometer after the Al-plated wafer is corroded by the stripping solution of Comparative Example 1.

[0050] in, Figure 1-14The left-center images are all wafer surface morphologies under OM dark field mode; the middle images are all surface morphologies at a magnification of 100 times; the right images are all three-dimensional profiles (surface roughness) of the wafer. DETAILED DESCRIPTION

[0051] Examples 1-7

[0052] A photoresist stripping solution, the components of which are shown in Table 1 by weight percentage, wherein the blank areas are added with 0:

[0053] Table 1

[0054]

[0055] The preparation method of the photoresist stripping solution is as follows: the components are mixed in proportion, stirred for 60 minutes, and filtered through a 0.2 micron filter element.

[0056] A method for using a photoresist stripping solution comprises the following steps: placing a wafer containing cured photoresist in the photoresist stripping solution for cleaning; the cleaning temperature is 70° C. and the cleaning time is 20 minutes.

[0057] Comparative Example 1

[0058] A photoresist stripping solution comprises the following components by weight: 10% dimethyl sulfoxide, 10% monoethanolamine, 0.05% L61, and the balance is made up of N-methylpyrrolidone.

[0059] Comparative Example 2

[0060] A photoresist stripping solution comprises the following components by weight: 10% dimethyl sulfoxide, 10% monoethanolamine, 0.05% 5-aminotetrazole, 0.05% L61, and the balance is made up of N-methylpyrrolidone.

[0061] Comparative Example 3

[0062] A photoresist stripping solution comprises the following components by weight: 10% dimethyl sulfoxide, 10% monoethanolamine, 0.05% gallic acid, 0.05% L61, and the balance is made up of N-methylpyrrolidone.

[0063] Comparative Example 4

[0064] A photoresist stripping solution comprises the following components by weight: 10% dimethyl sulfoxide, 10% monoethanolamine, 0.03% 5-aminotetrazole, 0.03% gallic acid, 0.05% L61, and the balance is made up of N-methylpyrrolidone.

[0065] Comparative Example 5

[0066] A photoresist stripping solution comprises the following components by weight: 10% dimethyl sulfoxide, 10% monoethanolamine, 0.6% 5-aminotetrazole, 0.6% gallic acid, 0.05% L61, and the balance is made up of N-methylpyrrolidone.

[0067] Performance testing methods

[0068] The stripping solutions prepared in the examples and comparative examples were subjected to performance tests, and the test data are listed in Table 2.

[0069] 1. Stripping ability: Clean the cured photoresist film using the stripping solution described in the examples and comparative examples. After drying, observe the glass surface using a scanning electron microscope to see if there is any residual adhesive. ○: indicates no residue; ☆: indicates some residue; ×: indicates residue.

[0070] 2. Corrosion resistance: Wafers plated with Ag or Al were placed in a 70°C stripping solution for 2 hours. After drying, they were tested using a 3D profilometer. ○ indicates no corrosion; × indicates corrosion.

[0071] 3. Stripping solution sol amount: Take 100g of stripping solution and put it into a beaker, heat it to 70℃, and continuously put 5cm×5cm pieces of cured photoresist into the stripping solution. The stripping time is 5 minutes, and the total number of pieces stripped when it fails is recorded; ○: indicates that the number of pieces stripped is greater than 250 pieces; ☆: indicates that the number of pieces stripped is between 150 and 250 pieces; ×: indicates that the number of pieces stripped is less than 150 pieces.

[0072] Performance test data

[0073] Table 2

[0074] Stripping ability Corrosion resistance Sol volume test Example 1 ○ ○ ○ Example 2 ○ ○ ○ Example 3 ○ ○ ○ Example 4 ○ ○ ○ Example 5 ○ ○ ○ Example 6 ○ ○ ○ Example 7 ○ ○ ○ Comparative Example 1 ○ × × Comparative Example 2 ○ × × Comparative Example 3 ○ × × Comparative Example 4 ○ × × Comparative Example 5 ○ × ×

[0075] Combined with Table 2, the photoresist stripping solution composition provided by the embodiment of the present invention has an excellent ability to remove the cured photoresist, such as Figure 1-7 As shown in FIG. 1 , the stripping solution of the embodiment has no corrosion on the wafer plated with Ag. Figure 13 As shown in FIG. 1 , the stripping solution of Example 1 has no corrosion on the Al-plated wafer; Figure 8-12 as well as Figure 14 As shown, the stripping solutions with components and contents outside the preferred range all caused certain corrosion to the wafers plated with Al or Ag.

Claims

1. A photoresist stripping solution, characterized in that The components include, by weight percentage, 69-89.85% of aprotic polar solvent, 10-30% of organic alkanolamine, 0.01-1.5% of metal inhibitor, and 0.05-0.3% of surfactant; the metal inhibitor includes at least one of tetrazole derivatives and gallic acid derivatives.

2. The photoresist stripping solution according to claim 1, wherein The metal inhibitors include tetrazole derivatives and gallic acid derivatives.

3. The photoresist stripping solution according to claim 2, wherein The weight ratio of the tetrazole derivative to the gallic acid derivative is (0.5-5):

1.

4. The photoresist stripping solution according to claim 3, wherein The weight ratio of the tetrazole derivative to the gallic acid derivative is (0.5-2.5):

1.

5. The photoresist stripping solution according to claim 1 or 4, characterized in that The content of the metal inhibitor in the photoresist stripping solution is 0.1-1 wt %.

6. The photoresist stripping solution according to claim 5, characterized in that The general structural formula of the tetrazole derivative is shown in Formula 1: Wherein R1 includes one of the following substituents: H, -NH2, -(CH2)nCH3, where 1≤n≤3; R2 includes one of the following substituents: -H, -NH2, -SH, -(CH2)nCH3 n NH2, -(CH2)nCH3, where 1≤n≤3.

7. The photoresist stripping solution according to claim 1, 3 or 6, wherein: The structure of the gallic acid derivative is shown in Structural Formula 2: Wherein R3 includes one of the following substituents: -H, -Na, -K, -(CH2)nCH3, 1≤n≤5.

8. The photoresist stripping solution according to claim 1, wherein The surfactant includes at least one of polyoxyethylene type and polyether type.

9. A method for using the photoresist stripping solution according to any one of claims 1 to 8, characterized in that: The following steps are involved: placing the wafer containing the cured photoresist in a photoresist stripping solution for cleaning; The cleaning temperature is 60-90° C. and the cleaning time is 10-40 minutes.

10. The method for using the photoresist stripping solution according to claim 9, wherein: The cleaning temperature is 65-80°C.

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