阅读说明：本技术 一种用于铜大马士革工艺的清洗液 (Cleaning solution for copper damascene process ) 是由 肖林成 刘兵 彭洪修 于 2020-05-15 设计创作，主要内容包括：一种用于铜大马士革工艺的清洗液,包括：氧化剂、螯合剂、有机碱、表面张力调节剂、金属缓蚀剂、有机酸铵盐、和水。本发明通过在清洗液中添加表面张力调节剂,在TiN硬掩模完全去除,金属材料、非金属材料以及低k介质材料得到很好的保护前提下,进一步降低了清洗液的表面张力,使金属缓蚀剂易于从晶圆表面脱附,进而使刻蚀残留物完全去除,进一步增强了清洗效果,提高了半导体器件的良率,且本申请的用于铜大马士革工艺的清洗液不含氟化物,操作窗口较大(适用于20℃～80℃),PH值适用范围广(pH值为5～14),在高端半导体清洗领域具有良好的应用前景。(A cleaning solution for a copper damascene process comprises the following components: an oxidizing agent, a chelating agent, an organic base, a surface tension regulator, a metal corrosion inhibitor, an organic acid ammonium salt, and water. According to the invention, the surface tension regulator is added into the cleaning solution, so that the surface tension of the cleaning solution is further reduced on the premise that the TiN hard mask is completely removed and the metal material, the non-metal material and the low-k dielectric material are well protected, the metal corrosion inhibitor is easy to desorb from the surface of the wafer, the etching residues are completely removed, the cleaning effect is further enhanced, and the yield of semiconductor devices is improved.)

1. A cleaning solution for a copper damascene process is characterized by comprising the following components: an oxidizing agent, a chelating agent, an organic base, a surface tension regulator, a metal corrosion inhibitor, an organic acid ammonium salt, and water.

2. The cleaning solution for copper damascene process as claimed in claim 1, wherein the content of said oxidizing agent is 0.1 wt% to 30 wt%.

3. The cleaning solution for copper damascene process as claimed in claim 1, wherein the chelating agent is contained in an amount of 0.05 to 1000 ppm.

4. The cleaning solution for copper damascene process as claimed in claim 3, wherein the chelating agent is contained in an amount of 0.1 to 10 ppm.

5. The cleaning solution for copper damascene process as claimed in claim 1, wherein the content of said organic base is 0.1 wt% to 20 wt%.

6. The cleaning solution for copper damascene process as claimed in claim 1, wherein the content of said surface tension modifier is 10ppm-10 wt%.

7. The cleaning solution for copper damascene process as claimed in claim 6, wherein the content of said surface tension modifier is 10ppm-5 wt%.

8. The cleaning solution for copper damascene process as claimed in claim 7, wherein the content of said surface tension modifier is 10 ppm-3%.

9. The cleaning solution for copper damascene process as claimed in claim 1, wherein said metal corrosion inhibitor is contained in an amount of 0.01 wt% to 20 wt%.

10. The cleaning solution for copper damascene process as claimed in claim 1, wherein the content of said organic acid ammonium salt is 0.01 wt% to 50 wt%.

11. The cleaning solution for copper damascene process as claimed in claim 1, wherein said water content is 35.1 wt% to 96.9 wt%.

12. The cleaning solution for copper damascene process as claimed in claim 1, wherein said oxidizing agent is selected from H₂O₂One or more of N-methylmorpholine oxide, benzoyl peroxide, peracetic acid, carbamide peroxide, nitric acid, peracetic acid, perbenzoic acid, or alloxan.

13. The cleaning solution for copper damascene process as claimed in claim 1, wherein said chelating agent is selected from glycine, serine, proline, leucine, alanine, aspartic acid, asparagine, glutamine, valine, lysine, cystine, ethylenediaminetetraacetic acid, trans-1, 2 cyclohexanediaminetetraacetic acid, uric acid, picolinic acid, nitrilotriacetic acid, hydroxyethylidene diphosphonic acid, ethylenediamine-N, N' -disuccinic acid, glutamic acid, diethylenetriaminepentaacetic acid, hydroxyethylethylenediaminetriacetic acid, iminodiacetic acid, nitrilotriacetic acid, salicylic acid, gluconic acid, nicotinic acid, tartaric acid, citric acid, 1,4,7, 10-tetraazacyclododecane-1, 4,7, 10-tetraacetic acid, ethyleneglycoltetraacetic acid, 1, 2-bis (o-aminophenoxy) ethane-N, one or more of N, N ', N ' -tetraacetic acid, ethylenediamine-N, N ' -bis (2-hydroxyphenylacetic acid), or propylenediaminetetraacetic acid.

14. The cleaning solution for copper damascene process as claimed in claim 1, wherein said organic base is selected from one or more of quaternary amine hydroxide, organic amine, or organic alcohol amine.

15. The cleaning solution for copper damascene process as claimed in claim 14 wherein said quaternary amine hydroxide is selected from one or more of tetramethyl ammonium hydroxide, tetraethyl ammonium hydroxide, trimethylphenyl ammonium hydroxide, tetrapropyl ammonium hydroxide, tetrabutyl ammonium hydroxide, benzyltrimethyl ammonium hydroxide, benzyltriethyl ammonium hydroxide, choline hydroxide, ammonium hydroxide, dodecyl trimethyl ammonium hydroxide, or hexadecyl trimethyl ammonium hydroxide.

16. The cleaning solution for copper damascene process as claimed in claim 14, wherein said organic amine is selected from one or more of monoethylamine, diethylamine, triethylamine, tripropylamine, N' N-diethylethylenediamine, hydroxyethylethylenediamine, cyclohexylamine, 1, 2-propanediamine, or pentamethyldiethylenetriamine.

17. The cleaning solution for copper damascene process as claimed in claim 14, wherein said organic alcohol amine is selected from one or more of monoethanolamine, diethanolamine, triethanolamine, diglycolamine, isopropanolamine, or N-methylethanolamine.

18. The cleaning solution for copper damascene process as claimed in claim 1, wherein the content of metal ions of said organic base is < 50 ppb.

19. The cleaning solution for copper damascene process according to claim 1, wherein the surface tension modifier is a polar organic monohydric alcohol and/or a polar organic ether, and the structural formula of the polar organic ether is R-O-R, R-O-R ', Ar-O-R, Ar-O-Ar or Ar-O-Ar', wherein R ═ hydrocarbon group, Ar ═ hydrocarbon group.

20. The cleaning solution for copper damascene process as claimed in claim 19, wherein said 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.

21. The cleaning solution for copper damascene process as claimed in claim 19, wherein said polar organic ether is selected from one or more of ethyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether, propylene glycol phenyl ether, methyl t-butyl ether, tetrahydrofuran, ethylene oxide, anisole, 1, 2-propylene oxide, 1, 4-dioxane, methallyl ether, n-propyl ether, or butyl glycidyl ether.

22. The cleaning solution for copper damascene process as claimed in claim 1, wherein said metal corrosion inhibitor is azole heterocyclic compound.

23. The cleaning solution for copper damascene process as claimed in claim 22, wherein said azole heterocyclic compound is selected from benzotriazole, 1,2, 4-triazole, 5-methylbenzotriazole, hydroxybenzotriazole, pyrazole, tolyltriazole, 3, 5-dimethylpyrazole, tetrazole, 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, 3-isopropyl-1, 2, 4-triazole, 2- (5-amino-pentyl) -benzotriazole, tolyltriazole, and tolyltriazole, One or more of 5-benzenethiol-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.

24. The cleaning solution for copper damascene process as claimed in claim 1, wherein said 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, tetraammonium ethylenediaminetetraacetic acid, triammonium ethylenediaminetetraacetate, diammonium ethylenediaminetetraacetate, ammonium succinate, 1-H-pyrazole-3-ammonium formate, ammonium malonate, ammonium adipate, or ammonium iminodiacetate.

Technical Field

The application relates to the field of wafer cleaning in the semiconductor manufacturing process, in particular to the field of high-end semiconductor cleaning solution for 14nm and smaller technical nodes.

Background

Copper is a stable metal that does not produce volatile byproducts when reacted with the etching gas, and thus cannot be etched directly using a dry etching process to form a metal interconnect line pattern, like aluminum, in an interconnect process. IBM has developed a damascene process in 1997, which forms a trench of a metal interconnect pattern on a dielectric material layer by photolithography and dry etching processes, deposits a metal barrier layer, a copper seed layer and copper metal, and removes the excess metal by CMP to form the desired metal interconnect. A multi-level copper interconnect process typically requires the use of a dual damascene process that simultaneously forms interconnect trenches and interconnect vias.

In the manufacture of Integrated Circuits (IC), the copper dual damascene process is more and more widely applied, and the cleaning of a high-speed rotating single chip microcomputer also becomes a mainstream cleaning mode. With the further reduction of the interconnect line feature size to 14nm and below technology nodes, plasma damage in the photoresist stripping process can have a severe impact on the mechanical and physical and chemical properties of the low-k material, so that the k value in the integrated structure is locally increased, and the advantages of the low-k dielectric material are weakened. In addition, due to the low surface energy and cross-linking properties of the etching residues, and the variation of the physical and chemical properties of the components of the etching residues, and the compatibility between the cleaning solution and the equipment film materials and structures, it is increasingly challenging to find a low surface tension cleaning solution that can effectively remove the plasma etching residues and protect the low-k dielectric materials, the non-metallic materials and the metallic materials.

At present, the main reports on semiconductor cleaning solutions in the field of integrated circuits are abroad. U.S. advanced technology materials corporation, patent CN101366107B, discloses an aqueous oxidizing composition for the removal of etch residues from microelectronic device substrates with high selectivity for the removal of Titanium (TiN) -containing hard mask materials, and methods of making and using the same. The substrate material is mainly low-k dielectric material such as organic polymer, organosilicate glass OSG, carbon-doped oxide (CDO) glass, tetraethyl orthosilicate (TEOS), FSG, etc., and the metal material is mainly copper and cobalt. The cleaning solution composition mainly uses H2O2 as an oxidant, amine substances such as primary amine, secondary amine, tertiary amine and amine-N-oxide as an oxidant stabilizer, at least one organic acid as a metal chelating agent, at least one azole as a metal corrosion inhibitor, a buffering agent, an organic cosolvent and water, and selectively and effectively removes residues after titanium-containing plasma etching, side wall polymerization residues, copper-containing through hole residues and/or a titanium-containing hard mask layer from a microelectronic device under the conditions of pH value of 3-9 and temperature of 30-50 ℃. The cleaning solution can be stable for 6-24 h to realize high-efficiency cleaning of residual materials from microelectronic devices, and simultaneously dielectric materials and metal interconnection materials cannot be damaged.

In a recent report, the company Versum Material, usa, disclosed in patent US2020035485a1 a composition for removing TiN hard masks from electronic circuit devices. The method mainly uses hydrogen peroxide as an oxidant, macromolecular organic acid as a hydrogen peroxide stabilizer, azoles and polyols as metal corrosion inhibitors, quaternary ammonium hydroxide and ammonium salt as an etchant, water as a solvent and optional fluoride to ensure the cleaning power, selectively removes titanium nitride and residues from the plasma etching process in the environment with the pH value of more than 5.5, and effectively protects second materials such as Cu, Co, low-k dielectric materials and the like. Copper loss is affected by the thickness of the copper oxide after removal by dilute hydrofluoric acid during wafer or device processing, and the invention mentions that corrosion inhibitors containing amino groups provide better copper oxide thickness performance.

Disclosure of Invention

In order to solve the problem that the cleaning solution for the copper damascene process in the prior art cannot completely remove etching residues in a metal pore channel, the application provides a cleaning solution for the copper damascene process, which comprises the following steps: an oxidizing agent, a chelating agent, an organic base, a surface tension regulator, a metal corrosion inhibitor, an organic acid ammonium salt, and water.

Further, the content of the oxidant is 0.1 wt% to 30 wt%.

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

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

Further, the content of the organic alkali is 0.1 wt% to 20 wt%.

Further, the content of the surface tension regulator is 10ppm-10 wt%.

Further, the content of the surface tension regulator is 10ppm to 5 wt%.

Further, the content of the surface tension regulator is 10 ppm-3%.

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

Further, the content of the organic acid ammonium salt is 0.01 wt% to 50 wt%.

Further, the content of the water is 35.1 wt% to 96.9 wt%.

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

Further, the chelating agent is selected from glycine, serine, proline, leucine, alanine, aspartic acid, asparagine, glutamine, valine, lysine, cystine, ethylenediaminetetraacetic acid (EDTA), trans-1, 2 cyclohexanediaminetetraacetic acid (CDTA), uric acid, picolinic acid, nitrilotriacetic acid (NTA), hydroxyethylidene diphosphonic acid (HEDP), ethylenediamine-N, N' -disuccinic acid (EDDS), glutamic acid, diethylenetriaminepentaacetic acid (DTPA), hydroxyethylethylenediaminetriacetic acid (HEDTA), iminodiacetic acid (IDA), nitrilotriacetic acid, salicylic acid, gluconic acid, nicotinic acid, tartaric acid, citric acid, 1,4,7, 10-tetraazacyclododecane-1, 4,7, 10-tetraacetic acid (DOTA), ethyleneglycoltetraacetic acid (EGTA), 1, 2-bis (o-aminophenoxy) ethane-N, one or more of N, N ', N ' -tetraacetic acid, ethylenediamine-N, N ' -bis (2-hydroxyphenylacetic acid) (HDDHA), or propylenediaminetetraacetic acid.

Further, the organic base is selected from one or more of quaternary amine hydroxide, organic amine, or organic alcohol amine.

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).

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

Further, the organic alcohol amine is selected from one or more of Monoethanolamine (MEA), Diethanolamine (DEA), Triethanolamine (TEA), Diglycolamine (DGA), isopropanolamine, or N-methylethanolamine.

Further, the content of metal ions of the organic base is < 50 ppb.

The surface tension regulator is a polar organic monohydric alcohol and/or a polar organic ether, the structural general formula of the polar organic ether is R-O-R, R-O-R ', Ar-O-R, Ar-O-Ar or Ar-O-Ar', wherein R ═ hydrocarbyl and R '═ hydrocarbyl, R and R' can be the same or different, and can be symmetrical ether and can be mixed ether, if R, R 'is carbon atoms at two ends of an organic group, the cyclic ether is called, Ar ═ arene and Ar ═ arene, and Ar' can be the same or different.

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.

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 tertiary butyl ether, Tetrahydrofuran (THF), ethylene oxide, anisole, 1, 2-propylene oxide, 1, 4-dioxane, methallyl ether, n-propyl ether, or butyl glycidyl ether.

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

Further, the azole heterocyclic compound is selected from Benzotriazole (BTA), 1,2, 4-triazole, 5-methylbenzotriazole (TTA), hydroxybenzotriazole, pyrazole, tolyltriazole, 3, 5-dimethylpyrazole, tetrazole, 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, 3-isopropyl-1, 2, 4-triazole, 2- (5-amino-pentyl) -benzotriazole, tolyltriazole, and tolyltriazole, One or more of 5-benzenethiol-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.

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, tetraammonium ethylenediaminetetraacetate (tetraammonium EDTA), triammonium EDTA, diammonium EDTA, ammonium succinate, 1-H-pyrazole-3-ammonium formate, ammonium malonate, ammonium adipate, or ammonium iminodiacetate. Preferably, the organic acid ammonium salt is an organic acid ammonium salt with strong chelating ability.

All materials and reagents of the present application are commercially available.

Compared with the prior art, the invention has the advantages that:

the invention discloses a cleaning solution for a copper damascene process, which is mainly used in the field of high-end semiconductor cleaning solutions of 14nm and smaller technical nodes. According to the invention, the surface tension regulator is added into the cleaning liquid, so that the surface tension of the cleaning liquid is further reduced on the premise that the TiN hard mask is completely removed and the metal material, the non-metal material and the low-k dielectric material are well protected, the metal corrosion inhibitor is easy to desorb from the surface of the wafer, further, etching residues in a metal pore channel of the cleaned wafer can be completely removed, the cleaning effect is further enhanced, and the yield of a semiconductor device is improved.

Detailed Description

The advantages of the invention are explained in detail below with reference to specific embodiments.

The preparation method comprises the following steps: the components were simply mixed according to the formulations (specific components and their corresponding specific contents) of the respective examples and comparative examples in the following table 1.

TABLE 1 formulation and cleaning temperature for different examples and comparative examples

Effects of the embodiment

Test objects and their sources for testing etch rates:

TiN (titanium nitride) blank wafer-Ramco Specialties Inc. (Lambda specialty Co., USA)

Cu (copper) blank wafer — Ramco Specialties Inc.

Blank wafer of Co-Ramco Specialties Inc.

SiON (silicon oxynitride) blank wafer — Ramco Specialties Inc.

TEOS (silicon dioxide) blank wafer — Ramco Specialties Inc.

BDII (Low dielectric constant silica) blank wafer — Ramco Specialties Inc.

The testing method of the etching rate of TiN, Cu, Co and other metals comprises the following steps:

(1) testing initial resistance values (Rs1) of 5 x 5cm metal blanks (TiN blanks, Cu blanks, Co blanks) by using a Napson four-point probe instrument;

(2) placing the 5 x 5cm metal blank wafer on a mini single chip microcomputer mini-SWT at 400rpm, treating the TiN blank wafer for 5min by cleaning solution, and chemically treating the Cu blank wafer and the Co blank wafer for 10 min;

(3) taking out the 5 x 5cm metal blank wafer, cleaning the 5 x 5cm metal blank wafer by using deionized water (DIW), drying the 5 x 5cm metal blank wafer by using high-purity nitrogen, and testing the resistance value (Rs2) of the 5 x 5cm metal blank wafer by using a Napson four-point probe instrument;

(4) the etching rate of the metal can be calculated by inputting the resistance value and the etching time into a proper program.

Non-metal etching Rate (Etch Rate) test methods such as SiON, TEOS, BDII and the like:

(1) starting a Nanospec6100 thickness meter according to the standard, selecting a proper test program, putting 5 x 5cm nonmetal blank wafers (SiON blank wafer, TEOS blank wafer and BDII blank wafer) on the Nanospec6100 thickness meter to test the thickness of the nonmetal blank wafers, rotating the nonmetal blank wafers by 90 degrees to continue the test, continuously testing for 4 times, and recording the numerical value;

(2) if the non-metal blank wafer is BDII, washing the BDII by water, treating the BDII for 20min at 350 ℃ in a muffle furnace, cooling the BDII to room temperature by a dryer, and testing the previous value; (other wafers do not require step 2)

(3) Treating the 5 x 5cm nonmetal blank wafer on a mini-SWT at 400rpm for 10min by using a cleaning solution;

(4) taking out the 5 x 5cm nonmetal blank wafer, cleaning with DIW, drying with high-purity nitrogen, testing the thickness of the wafer on a Nanospec6100 thickness meter according to the procedure 1, and recording the numerical value;

(5) if the non-metal blank wafer is BDII, washing the BDII by water, treating the BDII for 20min at 350 ℃ in a muffle furnace, cooling the BDII to room temperature by a dryer, and testing the BDII; (other wafers do not require step 5)

(6) The above-mentioned before and after thickness values and etching time are inputted into an appropriate program, and the etching rate is calculated as the change in thickness divided by the chemical treatment time.

Different cleaning solutions prepared according to the examples and comparative examples of table 1 were tested for surface tension using the pendant drop method using a kluzer model K100 surface tension meter. And testing the etching rates of different blank wafers according to the etching rate testing method, and testing the adsorption condition of the metal corrosion inhibitor on the surface of the copper or cobalt blank wafer by using an X-ray photoelectron spectroscopy (XPS), wherein the adsorption quantity of the metal corrosion inhibitor on the surface of the copper is judged according to the content of the N element on the surface of the copper because the metal corrosion inhibitor contains the N element. And simultaneously, cleaning the pattern wafer for 90s by using a mini-SWT single chip microcomputer at the temperature of 50 ℃ and the speed of 400rpm/min, rinsing the pattern wafer with water, drying the pattern wafer with nitrogen, and observing the cleaning effect of the pattern wafer by using a Hitachi SU8220 Scanning Electron Microscope (SEM). The etch rates, surface adsorption results, surface tensions and cleaning results for the different blank wafers are shown in table 2.

TABLE 2 etch Rate, surface adsorption results, surface tension and cleaning results for the different examples and comparative examples

As can be seen from table 2: the cleaning solution of the invention basically does not etch metals (such as Cu and Co) and non-metals (SiON, TEOS and BDII) used in the semiconductor manufacturing process under the condition that the TiN hard mask is completely removed, and the corrosion condition of the cleaning solution meets the requirement of the semiconductor industry on cleaning a high-speed rotating singlechip.

Comparison between the comparative example 1 and the example 30 shows that the surface tension of the solution is higher without adding the surface tension regulator, the adsorption (XPS) of the metal corrosion inhibitor on the surface of the blank copper chip is more, and the metal pore canal residue is more after the wafer is cleaned; the surface tension regulator neopentyl alcohol is added, the surface tension of the solution is reduced to a certain degree, the adsorption of the metal corrosion inhibitor on the surface of the blank copper chip is less than that of the metal corrosion inhibitor without the addition of the neopentyl alcohol, and then the cleaning residues on the pattern wafer are less.

Examples 30 and 31 show that the surface tension of the solution can be regulated and controlled by adding different concentrations of neopentyl alcohol, the surface tension of the solution is reduced along with the increase of the concentration of the neopentyl alcohol, and the adsorption amount of the corresponding cleaning liquid on the surface of the wafer and the residue after cleaning are gradually reduced, thereby being beneficial to improving the yield of semiconductor devices.

Comparative example 3 in comparison with example 31 shows that the surface tension of the cleaning solution comprising propylene glycol is much greater than the surface tension of the cleaning solution comprising monohydric alcohol, with the same mass of propylene glycol cleaning solution and with the same mass of monohydric alcohol cleaning solution; comparison between comparative example 4 and comparative example 3 and example 31 shows that the surface tension of the cleaning solution containing sorbitol is much greater than that of the cleaning solution containing neopentyl alcohol (monohydric alcohol) and propylene glycol (dihydric alcohol), which affects the adsorption and desorption processes of the cleaning solution on the wafer surface, and further affects the cleaning effect. As can be seen from example 31, comparative example 3 and comparative example 4 of table 2, the cleaning solution containing neopentyl alcohol was completely non-adsorbed on the wafer surface and the metal pore canal residue was completely cleaned, while the cleaning solution containing propylene glycol or sorbitol was slightly adsorbed on the wafer surface and a small amount of residue remained in the metal pore canal after cleaning. From this, it is found that the smaller the surface tension of the cleaning liquid, the easier the cleaning liquid is to desorb on the wafer surface, and the less the residue in the metal via after cleaning.

Comparison between the comparative example 2 and the example 32 shows that the solution has higher surface tension without adding the surface tension regulator, more adsorption on the surface of a blank copper wafer and more metal pore residues after the wafer is cleaned; the system added with the surface tension regulator propylene glycol phenyl ether can reduce the surface tension of the solution, reduce the adsorption of the solution on the surface of a blank copper wafer and improve the cleaning capability. Examples 32 and 33 show that the increase of the concentration of propylene glycol phenyl ether, the decrease of the surface tension of the solution, the further decrease of the adsorption amount and residue of the cleaning solution on the wafer surface, and the significant improvement of the cleaning effect. The principle is as follows: the alcohol ether polar organic matter contains hydrophilic radical in its molecule, and in the water solution, the hydrophilic radical contacts with water molecule and is attracted by water molecule downwards. Because the polarity of the hydrophilic group is weaker than that of water molecules, the attraction force is weaker than that between the water molecules, so that the surface of the aqueous solution with the arrangement of alcohol ether molecules is weaker than the state of unbalanced stress on the surface of the aqueous solution without polar organic matters such as alcohol ether and the like, the movement of molecules to the inside is weakened, the surface molecular density is increased, the effective distance between the molecules is shortened, the intermolecular attraction force is weakened, the degree of surface tension is reduced, and the surface tension is reduced.

In conclusion, the positive progress effects of the invention are as follows: according to the cleaning solution for the copper damascene process, the surface tension regulator is added, so that the surface tension of the cleaning solution is further reduced on the premise that the TiN hard mask is completely removed and the metal material, the nonmetal material and the low-k medium material are well protected, the metal corrosion inhibitor is easy to desorb from the surface of the wafer, the etching residues are completely removed, the cleaning effect is further enhanced, the yield of semiconductor devices is improved, the operation window is larger, and the cleaning solution has a good application prospect in the field of cleaning of high-end semiconductors.

The embodiments of the present invention have been described in detail, but the embodiments are merely examples, and the present invention is not limited to the embodiments described above. Any equivalent modifications and substitutions to those skilled in the art are also within the scope of the present invention. Accordingly, equivalent changes and modifications made without departing from the spirit and scope of the present invention should be covered by the present invention.