Cleaning solution for copper damascus process

Abstract

This invention provides a cleaning solution for copper damascus etching, comprising: an oxidant, a chelating agent, an organic base, a surface tension modifier, a metal corrosion inhibitor, an organic acid ammonium salt, and water. By adding a surface tension modifier to the cleaning solution, this invention further reduces the surface tension of the cleaning solution while ensuring complete removal of the TiN hard mask and good protection of metallic, non-metallic, and low-k dielectric materials. This facilitates the desorption of the metal corrosion inhibitor from the wafer surface, thereby completely removing etching residues and enhancing the cleaning effect. This improves the yield of semiconductor devices. Furthermore, the cleaning solution for copper damascus etching in this application is fluoride-free, has a large operating window (suitable for 20℃~80℃), and a wide pH range (pH 5~14), showing promising application prospects in the field of high-end semiconductor cleaning.

Description

[Technical Field]

[0001] This invention relates to the field of wafer cleaning in semiconductor manufacturing processes, and more particularly to a high-end semiconductor cleaning solution for 14nm and smaller technology nodes. [Previous Technology]

[0002] Copper is a stable metal that does not produce volatile byproducts when reacting with etching gases. Therefore, unlike aluminum, copper cannot be directly etched using dry etching processes to form metal interconnect patterns in interconnect technology. In 1997, IBM developed the damascus process. This process uses photolithography and dry etching to form trenches for metal interconnect patterns on a dielectric material layer, followed by the deposition of a metal barrier layer, a copper seed layer, and metallic copper. Excess metal is then removed using CMP (Chemical Metallurgy Processing) to form the desired metal interconnects. Multilayer copper interconnect processes generally require a dual damascus process that simultaneously forms interconnect trenches and interconnect vias.

[0003] In integrated circuit (IC) manufacturing, the copper double damask process is becoming increasingly widespread, and high-speed rotating microcontroller cleaning has also become the mainstream cleaning method. As interconnect feature sizes are further reduced to 14nm and below, plasma damage during processes such as resist removal can severely affect the mechanical and physicochemical properties of low-k materials, causing a local increase in the k-value in the integrated structure and weakening the advantages of low-k dielectric materials. In addition, due to the low surface energy and cross-linking properties of etching residues, as well as the changes in the physical and chemical properties of the residue components, coupled with the compatibility issues between the cleaning solution and the equipment film materials and structures, finding a low-surface-tension cleaning solution that can effectively remove plasma etching residues while protecting low-k dielectric materials, non-metallic materials, and metallic materials is becoming increasingly challenging.

[0004] Currently, reports on semiconductor cleaning solutions in the integrated circuit field are mainly from foreign sources. Advanced Technology Materials, Inc. of the United States disclosed in patent CN101366107B an aqueous oxide composition for highly selectively removing titanium-containing (TiN) hard mask materials from microelectronic device substrates, as well as its preparation and application method. The substrate materials mainly include low-k dielectric materials such as organic polymers, organosilicon glass (OSG), carbon oxide-doped (CDO) glass, tetraethyl orthosilicate (TEOS), and FSG, while the main metallic materials are copper and cobalt. This cleaning solution composition primarily uses H₂O₂ as an oxidant, and amines such as primary, secondary, and tertiary amines and amine-N-oxides as oxidant stabilizers. At least one organic acid is selected as a metal chelating agent, and at least one azole is selected as a metal corrosion inhibitor. Combined with a buffer, an organic co-solvent, and water, under pH 3–9 and temperature conditions of 30–50°C, it selectively and effectively removes titanium-containing plasma etching residues, sidewall polymerization residues, copper-containing via residues, and / or titanium-containing hard mask layers from microelectronic devices. This cleaning solution can remain stable for 6–24 hours, achieving efficient cleaning of residual materials from microelectronic devices without damaging dielectric materials and metal interconnect materials.

[0005] In a recent report, Versum Material, Inc. of the United States disclosed a composition for removing TiN hard masks from electronic circuit devices in patent US2020035485A1. The composition primarily uses hydrogen peroxide as an oxidant, macromolecular organic acids as hydrogen peroxide stabilizers, azoles and polyols as metal corrosion inhibitors, quaternary ammonium hydroxide and ammonium salts as etchants, and water as a solvent. Optional fluorides are added to ensure cleaning power. This method selectively removes titanium nitride and residues from plasma etching processes in an environment with a pH greater than 5.5, while effectively protecting secondary materials such as Cu, Co, and low-k dielectric materials. In wafer or device processing, copper loss after removal with dilute hydrofluoric acid is affected by the thickness of the copper oxide layer. This invention mentions that corrosion inhibitors containing amino groups can provide better copper oxide thickness performance. [Summary of the Invention]

[0006] In order to solve the problem that the cleaning solution used in the copper damascus process in the prior art cannot completely remove the etching residue in the metal channel, this application provides a cleaning solution for the copper damascus process, comprising: an oxidant, a chelating agent, an organic base, a surface tension modifier, a metal corrosion inhibitor, an organic acid ammonium salt and water.

[0007] Further, the content of the oxidant is 0.1 wt%-30 wt%.

[0008] Further, the content of the chelating agent is 0.05-1000ppm.

[0009] Further, the content of the chelating agent is 0.1-10 ppm.

[0010] Further, the content of the organic base is 0.1 wt%-20 wt%.

[0011] Further, the content of the surface tension modifier is 10 ppm-10 wt%.

[0012] Further, the content of the surface tension modifier is 10ppm-5wt%.

[0013] Further, the content of the surface tension modifier is 10ppm-3%.

[0014] Further, the content of the metal corrosion inhibitor is 0.01 wt%-20 wt%.

[0015] Further, the content of the organic acid ammonium salt is 0.01 wt%-50 wt%.

[0016] Further, the water content is 35.1 wt%-96.9 wt%.

[0017] Further, the oxidant is selected from one or more of H2O2, N-methylmorpholine oxide (NMMO or NMO), benzoyl peroxide, peracetic acid (CH3(CO)OOH), urea peroxide ((CO(NH2)2)H2O2), nitric acid, peracetic acid, perbenzoic acid or alloxan.

[0018] Further, the chelating agent is selected from glycine, serine, proline, leucine, alanine, aspartic acid, aspartamine, glutamine, valine, lysine, cystine, ethylenediaminetetraacetic acid (EDTA), trans-1,2-cyclohexanediaminetetraacetic acid (CDTA), uric acid, pyridinecarboxylic acid, nitroglycerin triacetic acid (NTA), hydroxyethylidene diphosphonic acid (HEDP), ethylenediamine-N,N'-disuccinic acid (EDDS), glutamic acid, diethylenetriaminepentaacetic acid (DTPA), hydroxyethylidene diphosphonic acid (HEDPA), etc. The following are some of the following: ethylenediaminetetraacetic acid (HEDTA), iminodiacetic acid (IDA), aminotriacetic acid, salicylic acid, gluconic acid, nicotinic acid, tartaric acid, citric acid, 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid (DOTA), ethylene glycol tetraacetic acid (EGTA), 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid, ethylenediamine-N,N'-bis(2-hydroxyphenylacetic acid) (HDDHA), or propylenediaminetetraacetic acid.

[0019] Further, the organic base is selected from one or more of quaternary amine hydroxides, organic amines, or organic alcohol amines.

[0020] Further, the quaternary amine hydroxide is selected from one or more of tetramethylammonium hydroxide (TMAH), tetraethylammonium hydroxide (TEAH), trimethylphenylammonium hydroxide (TMPAH), tetrapropylammonium hydroxide (TPAH), tetrabutylammonium hydroxide (TBAH), benzyltrimethylammonium hydroxide (BTMAH), benzyltriethylammonium hydroxide (BTEAH), choline hydroxide, ammonium hydroxide, dodecyltrimethylammonium hydroxide (DTAH), or hexadecyltrimethylammonium hydroxide (CTOH).

[0021] Further, the organic amine is selected from one or more of monoethylamine, diethylamine, triethylamine, tripropylamine, N,N-diethylethylenediamine, hydroxyethylethylenediamine, cyclohexylamine, 1,2-propanediamine, or pentamethyldiethylenetriamine.

[0022] Further, the organic alcohol amine is selected from one or more of monoethanolamine (MEA), diethanolamine (DEA), triethanolamine (TEA), diethylene glycolamine (DGA), isopropanolamine, or N-methylethanolamine.

[0023] Further, the content of metal ions in the organic base is <50 ppb.

[0024] Further, the surface tension modifier is a polar organic monohydric alcohol and / or a polar organic ether, the general structural formula of the polar organic ether is ROR, RO-R', Ar-OR, Ar-O-Ar or Ar-O-Ar', wherein R = hydrocarbon group, R' = hydrocarbon group, R and R' can be the same or different, if they are the same, it is a symmetrical ether, if they are different, it is a mixed ether, if R and R' are the carbon atoms at both ends of an organic group, it is called a cyclic ether, Ar = aromatic group, Ar' = aromatic group, Ar and Ar' can be the same or different.

[0025] Further, the polar organic monohydric alcohol is selected from one or more of methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, secondary butanol, tertiary butanol, neopentyl alcohol, cyclohexanol, octanol, benzyl alcohol, citronellol, or nerol.

[0026] Further, the polar organic ether is selected from one or more of diethyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether (DPM), propylene glycol phenyl ether, methyl tert-butyl ether, tetrahydrofuran (THF), ethylene oxide, anisole, 1,2-epoxypropane, 1,4-dioxane, methyl allyl ether, n-propyl ether, or butyl glycidyl ether.

[0027] Further, the metal corrosion inhibitor is an azole heterocyclic compound.

[0028] Further, the azole heterocyclic compound is selected from benzotriazole (BTA), 1,2,4-triazole, 5-methylbenzotriazole (TTA), hydroxybenzotriazole, pyrazole, toluenetriazole, 3,5-dimethylpyrazole, tetrazolium, 4-amino-1,2,4-triazole, benzothiazole, methyl-1H-benzotriazole (TTL), 2-aminobenzothiazole, 2-mercaptobenzothiazole, 3-amino-5-hydroxypyrazole, 1-phenylpyrazole, mercaptobenzimidazole, 5-aminotetrazole, 3-mercapto-1,2,4-triazole, One or more of the following: 3-isopropyl-1,2,4-triazole, 2-(5-amino-pentyl)-benzotriazole, 5-benzylthiol-benzotriazole, methyltetrazole, 5-phenyl-benzotriazole, 5-nitro-benzotriazole, 3-amino-5-mercapto-1,2,4-triazole, 1-amino-1,2,4-triazole, hydroxybenzotriazole, 1-amino-1,2,3-benzotriazole, or thiazole.

[0029] Further, the organic acid ammonium salt is selected from one or more of ammonium formate, ammonium oxalate, ammonium lactate, ammonium tartrate, triammonium citrate, ammonium acetate, ammonium carbamate, ammonium carbonate, ammonium benzoate, EDTA tetraammonium (EDTA tetraammonium), EDTA triammonium, EDTA diammonium, ammonium succinate, 1-H-pyrazole-3-carboxylate ammonium, ammonium malonate, ammonium adipate, or iminodiacetate ammonium. Preferably, the organic acid ammonium salt is an organic acid ammonium salt with strong chelating ability.

[0030] All materials and reagents used in this application are commercially available.

[0031] Compared with the prior art, the advantages of the present invention are as follows:

[0032] This invention discloses a cleaning solution for copper damascus etching, primarily for use in the field of high-end semiconductor cleaning solutions for 14nm and smaller technology nodes. By adding a surface tension modifier to the cleaning solution, this invention further reduces the surface tension of the cleaning solution while ensuring complete removal of the TiN hard mask and good protection of metallic, non-metallic, and low-k dielectric materials. This facilitates the desorption of metal corrosion inhibitors from the wafer surface, thereby enabling the complete removal of etching residues within the metal channels of the wafer after cleaning. This further enhances the cleaning effect and improves the yield of semiconductor devices. Furthermore, the cleaning solution for copper damascus etching in this application is fluoride-free, has a large operating window (suitable for 20℃~80℃), and a wide pH range (pH 5~14), demonstrating promising application prospects in the field of high-end semiconductor cleaning.

Implementation Method

[0033] The advantages of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments.

[0034] Preparation method: The components are simply mixed according to the formulations (specific components and their corresponding specific contents) of the various examples and comparative examples in Table 1 below.

[0035] Table 1. Formulations and cleaning temperatures of different embodiments and comparative examples Oxidizing agent wt% Chelating agents ppm Organic bases wt% Surface tension modifier Metal corrosion inhibitor wt Organic acid ammonium salt wt% Water wt% Temperature ℃ Example 1 H2O2: 3.0 Glycine: 0.5 TMAH: 0.4 Benzyl alcohol: 0.1 wt% BTA: 0.5 Ammonium formate: 0.5 95.5 50℃ Example 2 H2O2: 6.0 EDTA: 1.0 TEAH: 1.0 n-Butanol: 0.5 wt% 1,2,4-Triazole: 1.0 Ammonium oxalate: 0.2 91.3 50℃ Example 3 H2O2: 9.0 CDTA: 100 TBPH: 1.0 Neopentyl alcohol: 1.0 wt% TTA: 1.0 Ammonium lactate: 2.0 85.99 50℃ Example 4 H2O2: 12.0 Uric acid: 0.05 BTMAH: 0.5 Cyclohexanol: 2.0 wt% Hydroxybenzotriazole: 1.0 Ammonium tartrate: 1.0 83.5 50℃ Example 5 H2O2: 15.0 Pyridinecarboxylic acid: 1 BTEAH: 10 Isopropanol: 5.0 wt% Pyrazole: 1.0 Ammonium citrate: 1.0 68.0 50℃ Example 6 H2O2: 18.0 IDA: 10 Isopropanolamine: 1 Octyl alcohol: 8.0 wt% Toluenetriazole: 0.5 Ammonium lactate: 1 71.5 50℃ Example 7 H2O2: 21.0 EDDS: 8 DTAH: 1.0 Ethanol: 10.0 wt% Tetrazolium: 5 Ammonium carbamate: 1.0 62.0 50℃ Example 8 H2O2: 24.0 Glutamic acid: 80 CTOH: 1.0 n-Propanol: 0.05 wt% Benzothiazol: 0.5 Ammonium carbonate: 0.5 73.95 50℃ Example 9 H2O2: 27.0 DTPA: 8 Monoethylamine: 10 Propylene glycol methyl ether: 1.5 wt% 2-Aminobenzothiazole: 0.01 Ammonium benzoate: 1.0 60.49 50℃ Example 10 NMO: 0.1 HEDTA: 8 Diethylamine: 1.0 DPM: 0.5 wt% 2-Mercaptobenzothiazole: 0.5 EDTA tetraammonium: 1.0 96.9 20℃ Example 11 Peracetic acid: 30.0 HEDP: 0.1 Triethylamine: 1.0 Ethylene oxide: 2.5 wt% TTL: 0.5 EDTA triammonium: 1.0 65.0 30℃ Example 12 Benzoic acid peroxide: 5.3 EGTA: 8 Cyclohexylamine: 1.0 Benzyl ether: 10 ppm Methyltetrazole: 0.5 EDTA diammonium: 1.0 92.2 40℃ Example 13 H2O2: 18.0 Ammoniated triacetic acid: 5 MEA: 0.1 Ether: 20ppm 1-Amino-1,2,4-triazole: 3.5 Ammonium succinate: 0.8 77.6 50℃ Example 14 H2O2: 16.0 Niacin: 10 DEA: 0.5 n-Propyl ether: 50 ppm Hydroxybenzotriazole: 5 1-H-pyrazole-3-carboxylic acid ammonium: 3.5 75.0 50℃ Example 15 H2O2: 14.0 Tartaric acid: 20 TEA: 1 Butyl glycidyl ether: 100 ppm Thiazole: 0.5 Ammonium malonate: 2.5 82.0 50℃ Example 16 H2O2: 18.0 Citric acid: 30 DGA: 2 Citronellol: 200ppm 3-Mercapto-1,2,4-triazole: 0.05 Ammonium adipate: 10 69.95 20℃ Example 17 Alloxan: 8 DOTA: 40 Isopropanolamine: 4 Nerol: 500ppm 5-Nitro-benzotriazole: 0.5 Ammonium iminodiacetate: 2.4 85.1 30℃ Example 18 H2O2: 12.0 Leucine: 8 MEA: 2 DPM: 800ppm 4-Amino-1,2,4-triazole: 0.25 Ammonium benzoate: 1 84.75 50℃ Example 19 Nitric acid: 5.0 HDDHA: 60 DEA: 8 Methanol: 0.1 wt% Mercaptobenzimidazole: 0.5 Ammonium benzoate: 0.01 86.39 40℃ Example 20 NMO: 5.5 Aspartic acid: 70 TMPAH: 10 n-Propanol: 0.2 wt% 3,5-Dimethylpyrazole: 3.5 Ammonium acetate: 1 79.8 60℃ Example 21 H2O2: 10.0 Gluconic acid: 80 1,2-Propanediamine: 12 Isobutanol: 0.5 wt% 1-Phenylopyrazole: 5 Ammonium citrate: 5 67.5 70℃ Example 22 H2O2: 9.0 Serine: 90 TPAH: 15 THF: 1.0 wt% 5-Aminotetrazole: 15 Ammonium tartrate: 10 50.0 80℃ Example 23 Benzoyl peroxide: 8.0 Salicylic acid: 5 Choline hydroxide: 1 Propylene glycol phenyl ether: 1.5 wt% 3-Amino-5-hydroxypyrazole: 0.5 Ammonium acetate: 1.0 88.0 50℃ Example 24 Carbohydrate peroxide: 6.0 Propylenediaminetetraacetic acid: 200 N-Methylethanolamine: 20 1,4-Dioxane: 3.0 wt% 3-Isopropyl-1,2,4-triazole: 10 Ammonium oxalate: 2 58.98 50℃ Example 25 Peracetic acid: 4.0 Proline: 0.05 Ammonium hydroxide: 5 Methyl tert-butyl ether: 5.0 wt% 1-Amino-1,2,3-benzotriazole: 20 Ammonium formate: 30 36.0 50℃ Example 26 NMMO: 2.0 Aspartic acid: 0.5 Tripropylamine: 1.0 1,2-Propylene oxide: 8.0 wt% 5-Phenylacetazole: 0.5 Ammonium tartrate: 40 48.5 50℃ Example 27 H2O2: 3.0 NTA: 1 N,N-Diethylethylenediamine: 1.0 Methyl allyl ether: 10.0 wt% 2-(5-Amino-pentyl)-benzotriazole: 0.9 Ammonium citrate: 50 35.1 50℃ Example 28 H2O2: 22.0 Lysine: 1000 Hydroxyethyl ethylenediamine: 0.5 Secondary butanol: 0.5 wt% 5-Benzylthiol-benzotriazole: 0.5 Ammonium tartrate: 0.5 75.9 50℃ Example 29 H2O2: 15.0 Cystine: 3 Pentamethyldiethylenetriamine: 1.0 Tertiary butanol: 0.5 wt% 3-Amino-5-mercapto-1,2,4-triazole: 0.5 Ammonium benzoate: 0.5 82.5 60℃ Example 30 H2O2: 16.0 Glutamic acid: 3 TMAH: 0.4 Neopentyl alcohol: 0.05 wt% BTA: 0.3 Ammonium benzoate: 0.5 82.75 50℃ Example 31 H2O2: 16.0 Glutamic acid: 3 TMAH: 0.4 Neopentyl alcohol: 0.5 wt% BTA: 0.3 Ammonium benzoate: 0.5 82.3 50℃ Example 32 H2O2: 16.0 EDTA: 3 TEA: 0.4 Propylene glycol phenyl ether: 0.1 wt% TTL: 0.3 Ammonium tartrate: 0.5 82.7 50℃ Example 33 H2O2: 16.0 EDTA: 3 TEA: 0.4 Propylene glycol phenyl ether: 0.3 wt% TTL: 0.3 Ammonium tartrate: 0.5 82.5 50℃ Comparative Example 1 H2O2: 16.0 Glutamic acid: 3 TMAH: 0.4 / BTA: 0.3 Ammonium benzoate: 0.5 82.8 50℃ Comparative Example 2 H2O2: 16.0 EDTA: 3 TEA: 0.4 / TTL: 0.3 Ammonium tartrate: 0.5 82.8 50℃ Comparative Example 3 H2O2: 16.0 Glutamic acid: 3 TMAH: 0.4 Propylene glycol: 0.5 wt% BTA: 0.3 Ammonium benzoate: 0.5 82.3 50℃ Comparative Example 4 H2O2: 16.0 Glutamic acid: 3 TMAH: 0.4 Sorbitol: 0.5 wt% BTA: 0.3 Ammonium benzoate: 0.5 82.3 50℃

[0036] Effective Examples

[0037] Test objects used for testing etching rates and their sources: TiN (Titanium Nitride) blank wafer – Ramco Specialties Inc. (USA) Cu (Copper) blank wafer – Ramco Specialties Inc. Co (Cobalt) blank wafer – Ramco Specialties Inc. SiON (Silicon Oxide) blank wafer – Ramco Specialties Inc. TEOS (Silicon Dioxide) blank wafer – Ramco Specialties Inc. BDII (Low Dielectric Silicon Oxide) blank wafer – Ramco Specialties Inc.

[0038] Method for testing the etching rate of metals such as TiN, Cu, and Co: (1) Use a Napson four-point probe to test the initial resistance value (Rs1) of a 5*5cm blank metal wafer (TiN blank wafer, Cu blank wafer, Co blank wafer); (2) Run the 5*5cm blank metal wafer on a mini-SWT microcontroller at 400rpm. Treat the TiN blank wafer with cleaning solution for 5min, and chemically treat the Cu and Co blank wafers for 10min; (3) Take out the 5*5cm blank metal wafer, clean it with deionized water (DIW), blow it dry with high-purity nitrogen, and then use a Napson four-point probe to test the resistance value (Rs2) of the 5*5cm blank metal wafer; (4) Input the above resistance value and etching time into a suitable program to calculate the etching rate of the metal.

[0039] Test method for non-metallic etching rate (Etch Rate) of SiON, TEOS, BDII, etc.: (1) Turn on the Nanospec6100 thickness gauge according to the standard, select the appropriate test program, put the 5*5cm non-metallic blank wafer (SiON blank wafer, TEOS blank wafer, BDII blank wafer) into the Nanospec6100 thickness gauge to test the thickness of the non-metallic blank wafer, rotate the non-metallic blank wafer 90° and continue to test, test 4 times in a row and record the value; (2) If the non-metallic blank wafer is BDII, it needs to be rinsed with water, treated in a muffle furnace at 350℃ for 20min, and cooled to room temperature in a dryer before testing the previous value; (other wafers do not need step 2) (3) Treat the 5*5cm non-metallic blank wafer at 400rpm on a mini-SWT with cleaning solution for 10min; (4) Take out the 5*5cm non-metallic blank wafer, clean it with DIW, dry it with high-purity nitrogen, test the wafer thickness on the Nanospec6100 thickness gauge according to program 1, and record the value; (5) If the non-metallic blank wafer is BDII, it needs to be rinsed with water, treated in a muffle furnace at 350℃ for 20 minutes, cooled to room temperature in a dryer, and then the value is tested; (step 5 is not required for other wafers) (6) Input the above thickness values ​​and etching time into a suitable program. The etching rate is calculated as the thickness change divided by the chemical treatment time.

[0040] The surface tension of different cleaning solutions prepared according to the examples and comparative examples in Table 1 was tested using a Krüz K100 surface tension meter with the pendant drop method. The etching rate of different blank wafers was tested according to the above etching rate test method, and the adsorption of metal corrosion inhibitors on the surface of copper or cobalt blank wafers was tested using X-ray photoelectron spectroscopy (XPS). Since the metal corrosion inhibitors contain nitrogen, the amount of metal corrosion inhibitors adsorbed on the copper surface was determined by the nitrogen content on the copper surface. At the same time, the patterned wafers were cleaned for 90 seconds using a mini-SWT microcontroller at 50°C and 400 rpm / min, rinsed with water, dried with nitrogen, and the cleaning effect of the patterned wafers was observed using a Hitachi SU8220 scanning electron microscope (SEM). The etching rate, surface adsorption results, surface tension, and cleaning effect of different blank wafers are shown in Table 2.

[0041] Table 2 Etching rate, surface adsorption results, surface tension and cleaning results of different embodiments and comparative examples Titanium nitride etching rate Metal Etching Rate Non-metallic etch rate Surface adsorption results Surface tension Graphic wafers Cleaning results TiN ER (Å / min) Cu ER (Å / min) Co ER (Å / min) SiON ER (Å / min) TEOS ER (Å / min) BDII ER (Å / min) XPS (Based on N) Hanging drop method (mN / m) Damascus metal channel Example 30 246.31 0.68 0.22 0.13 0.31 -0.17 ○ 64.20 ○ Example 31 246.83 0.71 0.18 0.12 0.27 0.11 ◎ 53.35 ◎ Example 32 253.69 0.62 0.17 0.21 0.23 -0.12 ○ 62.56 ○ Example 33 255.31 0.67 0.22 0.12 0.18 -0.11 ◎ 60.09 ◎ Comparative Example 1 246.65 0.76 0.17 0.06 0.24 -0.11 △ 64.85 △ Comparative Example 2 254.58 0.69 0.19 -0.04 0.17 0.13 △ 63.06 △ Comparative Example 3 247.04 0.62 0.05 0.13 0.11 -0.08 ○ 63.88 ○ Comparative Example 4 247.37 0.58 0.17 -0.05 -0.09 0.14 ○ 64.76 ○ Surface adsorption results (XPS) Wafer cleaning results ◎ Completely non-adsorbent ◎ Clean thoroughly ○ Slight adsorption ○ Small amount of residue △ More adsorption △ A significant amount of residue × Severe adsorption × Large amount of residue

[0042] As can be seen from Table 2, the cleaning solution of the present invention will not etch metals (such as Cu and Co) and non-metals (SiON, TEOS, BDII) used in semiconductor processes when the TiN hard mask is completely removed. The corrosion conditions meet the requirements of the semiconductor industry for cleaning microcontrollers at high speeds.

[0043] Comparison of Example 1 and Example 30 shows that without the addition of a surface tension modifier, the surface tension of the solution is high, the adsorption of metal corrosion inhibitor on the surface of the blank copper wafer (XPS) is greater, and there are more metal channel residues after wafer cleaning; with the addition of the surface tension modifier neopentyl alcohol, the surface tension of the solution is reduced to a certain extent, the adsorption of metal corrosion inhibitor on the surface of the blank copper wafer is also less than that without the addition, and thus there are fewer cleaning residues on the patterned wafer.

[0044] Examples 30 and 31 show that by adding different concentrations of neopentyl alcohol, the surface tension of the solution can be controlled. As the concentration of neopentyl alcohol increases, the surface tension of the solution decreases, and the amount of cleaning solution adsorbed on the wafer surface and the residue after cleaning are gradually reduced, which is beneficial to improving the yield of semiconductor devices.

[0045] Comparison Example 3 with Example 31 shows that, for cleaning solutions containing the same quality of propylene glycol and monohydric alcohol, the surface tension of the cleaning solution containing propylene glycol is much greater than that of the cleaning solution containing monohydric alcohol. Comparison Example 4 with Comparative Example 3 and Example 31 shows that the surface tension of the cleaning solution containing the same quality of sorbitol is much greater than that of the cleaning solution containing the same quality of neopentyl alcohol (monohydric alcohol), and also slightly greater than that of the cleaning solution containing the same quality of propylene glycol (diol). This will affect the adsorption and desorption process of the cleaning solution on the wafer surface, thus affecting the cleaning effect. As shown in Table 2, Example 31, Comparative Example 3 and Comparative Example 4 show that the cleaning solution containing neopentyl alcohol has no adsorption on the wafer surface, and the metal channel residues are completely cleaned. However, the cleaning solutions containing propylene glycol or sorbitol have slight adsorption on the wafer surface, and a small amount of residues remain in the metal channels after cleaning. Therefore, the lower the surface tension of the cleaning solution, the easier it is for the cleaning solution to desorb from the wafer surface, and the less residue remains in the metal channels after cleaning.

[0046] Comparative Example 2 and Example 32 show that without the addition of a surface tension modifier, the surface tension of the solution is high, resulting in more adsorption on the surface of the blank copper wafer and more metal channel residue after wafer cleaning. The system with the addition of the surface tension modifier propylene glycol phenyl ether can reduce the surface tension of the solution, decrease the adsorption of the solution on the surface of the blank copper wafer, and improve the cleaning ability. Examples 32 and 33 show that increasing the concentration of propylene glycol phenyl ether reduces the surface tension of the solution, further reducing the amount of cleaning solution adsorbed on the wafer surface and the residue, significantly improving the cleaning effect. The principle is that alcohol ethers are polar organic compounds containing hydrophilic groups in their molecules. In aqueous solution, the hydrophilic groups come into contact with water molecules and are attracted downwards by the water molecules. Because the polarity of hydrophilic groups is weaker than that of water molecules, this attraction is weaker than the attraction between water molecules. Therefore, the surface of an aqueous solution with alcohol and ether molecules is less unbalanced than the surface of an aqueous solution without polar organic substances such as alcohols and ethers. The inward movement of molecules is weakened, the surface molecular density increases, the effective distance between molecules becomes shorter, the intermolecular attraction weakens, the surface "tightness" decreases, and the surface tension decreases.

[0047] In summary, the positive and progressive effects of the present invention are as follows: The cleaning solution developed by the present invention for copper damascus steel processing, by adding a surface tension modifier, further reduces the surface tension of the cleaning solution under the premise that the TiN hard mask is completely removed and the metal materials, non-metal materials and low-k dielectric materials are well protected. This makes it easier for the metal corrosion inhibitor to desorb from the wafer surface, completely removes the etching residue, further enhances the cleaning effect, improves the yield of semiconductor devices, has a larger operating window, and has good application prospects in the field of high-end semiconductor cleaning.

[0048] The specific embodiments of the present invention have been described in detail above, but they are merely 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 to the present invention are also within the scope of the present invention. Therefore, all equivalent transformations and modifications made without departing from the spirit and scope of the present invention should be covered within the scope of the present invention. [Simplified Explanation of the Diagram]

[0050] None [Biomaterial Storage]

[0051] None

Claims

1. A cleaning solution for copper damascus sizing, characterized in that the cleaning solution comprises an oxidizing agent, a chelating agent, an organic base, a surface tension modifier, a metal corrosion inhibitor, an organic acid ammonium salt, and water, wherein, The surface tension modifier is a polar organic monohydric alcohol and / or a polar organic ether, wherein the polar organic ether has the general structural formula ROR, RO-R', Ar-OR, Ar-O-Ar, or Ar-O-Ar', wherein R = hydrocarbon group, R' = hydrocarbon group, Ar = aromatic group, and Ar' = aromatic group; and the polar organic monohydric alcohol is selected from one or more of methanol, ethanol, n-propanol, isopropanol, n-butanol, isobutanol, secondary butanol, tertiary butanol, neopentyl alcohol, cyclohexanol, octanol, benzyl alcohol, citronellol, or nerol; the content of the organic acid ammonium salt is 0.01 wt%-50 wt%; the content of the surface tension modifier is 10 ppm-5 wt%; the content of the oxidant is 0.1 wt%-30 wt%; the content of the chelating agent is 0.05-1000 ppm; and the content of the organic base is 0.1 wt%-20 wt%. The content of the metal corrosion inhibitor is 0.01 wt%-20 wt%; the content of the water is 35.1 wt%-96.9 wt%.

2. The cleaning solution for the copper damascus process as described in claim 1, wherein, The content of the chelating agent is 0.1-10 ppm.

3. The cleaning solution for the copper damascus process as described in claim 1, wherein, The content of the surface tension modifier is 10 ppm to 10 wt%.

4. The cleaning solution for the copper damascus process as described in claim 3, wherein, The content of the surface tension modifier is 10 ppm to 3 wt%.

5. The cleaning solution for the copper damascus process as described in claim 1, wherein, The oxidant is selected from one or more of H2O2, N-methylmorpholine oxide, benzoyl peroxide, peracetic acid, urea peroxide, nitric acid, peracetic acid, perbenzoic acid, or alloxan.

6. The cleaning solution for the copper damascus process as described in claim 1, wherein, The chelating agent is selected from one or more of glycine, serine, proline, leucine, alanine, aspartic acid, aspartamine, glutamine, valine, lysine, cystine, ethylenediaminetetraacetic acid, trans-1,2-cyclohexanediaminetetraacetic acid, uric acid, pyridinecarboxylic acid, hypozoxytriacetic acid, hydroxyethylidene diphosphonic acid, ethylenediamine-N,N'-disuccinic acid, glutamic acid, diethylenetriaminepentaacetic acid, hydroxyethylethylenediaminetriacetic acid, iminodiacetic acid, aminotriacetic acid, salicylic acid, gluconic acid, nicotinic acid, tartaric acid, citric acid, 1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid, ethylene glycol tetraacetic acid, 1,2-bis(o-aminophenoxy)ethane-N,N,N',N'-tetraacetic acid, ethylenediamine-N,N'-bis(2-hydroxyphenylacetic acid), or propylenediaminetetraacetic acid.

7. The cleaning solution for the copper damascus process as described in claim 1, wherein, The organic base is selected from one or more of quaternary amine hydroxides, organic amines, or organic alcohol amines.

8. The cleaning solution for the copper damascus process as described in claim 7, wherein, The quaternary amine hydroxide is selected from one or more of tetramethylammonium hydroxide, tetraethylammonium hydroxide, trimethylphenylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, benzyltrimethylammonium hydroxide, benzyltriethylammonium hydroxide, choline hydroxide, ammonium hydroxide, dodecyltrimethylammonium hydroxide, or hexadecyltrimethylammonium hydroxide.

9. The cleaning solution for the copper damascus process as described in claim 7, wherein, The organic amine is selected from one or more of monoethylamine, diethylamine, triethylamine, tripropylamine, N,N-diethylethylenediamine, hydroxyethylethylenediamine, cyclohexylamine, 1,2-propanediamine, or pentamethyldiethylenetriamine.

10. The cleaning solution for the copper damascus process as described in claim 7, wherein, The organic alcohol amine is selected from one or more of monoethanolamine, diethanolamine, triethanolamine, diethylene glycolamine, isopropanolamine, or N-methylethanolamine.

11. The cleaning solution for the copper damascus process as described in claim 1, wherein, The content of metal ions in the organic base is <50 ppb.

12. The cleaning solution for the copper damascus process as described in claim 1, wherein, The polar organic ethers are selected from one or more of the following: diethyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether, propylene glycol phenyl ether, methyl tert-butyl ether, tetrahydrofuran, ethylene oxide, anisole, 1,2-epoxypropane, 1,4-dioxane, methyl allyl ether, n-propyl ether, or butyl glycidyl ether.

13. The cleaning solution for the copper damascus process as described in claim 1, wherein, The metal corrosion inhibitor is an azole heterocyclic compound.

14. The cleaning solution for the copper damascus process as described in claim 13, wherein, The azole heterocyclic compounds are selected from benzotriazole, 1,2,4-triazole, 5-methylbenzotriazole, hydroxybenzotriazole, pyrazole, toluenetriazole, 3,5-dimethylpyrazole, tetrazolium, 4-amino-1,2,4-triazole, benzothiazole, methyl-1H-benzotriazole, 2-aminobenzothiazole, 2-mercaptobenzothiazole, 3-amino-5-hydroxypyrazole, 1-phenylpyrazole, mercaptobenzimidazole, 5-aminotetrazole, 3-mercapto-1,2,4-triazole. One or more of the following: 3-isopropyl-1,2,4-triazole, 2-(5-amino-pentyl)-benzotriazole, 5-benzylthiol-benzotriazole, methyltetrazole, 5-phenyl-benzotriazole, 5-nitro-benzotriazole, 3-amino-5-mercapto-1,2,4-triazole, 1-amino-1,2,4-triazole, hydroxybenzotriazole, 1-amino-1,2,3-benzotriazole, or thiazole.

15. The cleaning solution for the copper damascus process as described in claim 1, wherein, The organic acid ammonium salt is selected from one or more of the following: ammonium formate, ammonium oxalate, ammonium lactate, ammonium tartrate, triammonium citrate, ammonium acetate, ammonium carbamate, ammonium carbonate, ammonium benzoate, ethylenediaminetetraacetate tetraammonium, ethylenediaminetetraacetate triammonium, ethylenediaminetetraacetate diammonium, ammonium succinate, 1-H-pyrazole-3-carboxylate ammonium, ammonium malonate, ammonium adipate, or iminodiacetate ammonium.