An etching composition

Abstract

This invention provides a titanium nitride etching composition comprising an oxide, a corrosion inhibitor, an ammonium salt, a surfactant, and water. Using this composition, titanium nitride can be effectively removed while avoiding etching of silicon oxide, providing a wide operating window and showing promising application prospects in semiconductor etching processes.

Description

Technical Field

[0001] This invention relates to an etching composition, and more particularly to a titanium nitride etching composition. Background Technology

[0002] As scale continues to shrink to smaller feature sizes, the reliability of integrated circuits (ICs) is receiving increasing attention in IC manufacturing technology. Higher device performance and reliability requirements place greater demands on integration schemes, interconnect materials, and process flows. Optimal low-k dielectric materials and their associated deposition, patterning, photolithography, etching, and cleaning processes are needed to form dual damascene interconnect patterns. The hard mask design approach for interconnect pattern mirror fabrication utilizes the ability to transfer patterns to the underlying layer with the most stringent optimal dimensional control.

[0003] As technology nodes advance to nanotechnology, metallic hard mask materials such as titanium nitride are used to achieve better etch / removal selectivity, better pattern retention, and contour control compared to low-k materials during patterning etching. After patterning is complete, these types of metallic hard masks need to be withdrawn from or removed from the substrate. Summary of the Invention

[0004] The present invention provides an etching composition comprising: an oxide, a corrosion inhibitor, an ammonium salt, a surfactant, and water.

[0005] Further, the oxidant is selected from one or more of hydrogen peroxide, periodic acid, iodic acid, nitric acid, ammonium chlorate, ammonium iodate, ammonium perborate, ammonium perchlorate, ammonium periodate, ammonium persulfate, peracetic acid, perbenzoic acid, 1,4-benzoquinone, chlorobenzoquinone, and N-methylmorpholine N-oxide.

[0006] Further, the corrosion inhibitor is selected from one or more of 5-aminotetrazole, 1-hydroxy-benzotriazole, benzimidazole, pyrazole, benzotriazole, 1,2,4-triazole, 5-methyl-benzotriazole, 3-amino-1,2,4-triazole, 3-mercapto-1,2,4-triazole, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 3-amino-5-mercapto-1,2,4-triazole, pentylenetetrazol, 5-phenyl-1H-tetrazole, 3-amino-5-methylthio-1H-1,2,4-triazole, benzothiazole, imidazole, indazole, and carbazole.

[0007] Furthermore, the ammonium salt is selected from one or more of ammonium phosphate, diammonium hydrogen phosphate, diammonium hydrogen phosphate, ammonium sulfate, ammonium sulfite, ammonium thiosulfate, ammonium thiocyanate, ammonium acetate, ammonium benzoate, ammonium citrate, ammonium hydrogen citrate, ammonium tartrate, ammonium succinate, and ammonium lactate.

[0008] Furthermore, the surfactant is selected from one or more of hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, hexadecylpyridinium chloride monohydrate, benzylammonium chloride, benzyldimethyldodecylammonium chloride, benzyldimethylhexadecylammonium chloride, dodecyltrimethylammonium chloride, tetraheptylammonium bromide, tetra(decyl)ammonium bromide, tetradecyltrimethylammonium chloride, decyltrimethylammonium chloride, and benzyldimethylammonium chloride.

[0009] Furthermore, the oxidant has a mass percentage concentration of 5wt%-20wt%.

[0010] Furthermore, the mass percentage concentration of the corrosion inhibitor is 0.1wt%-2wt%.

[0011] Furthermore, the mass percentage concentration of the ammonium salt is 0.2wt%-5wt%.

[0012] Furthermore, the mass percentage concentration of the surfactant is 0.1wt%-2wt%.

[0013] This invention provides a titanium nitride etching composition. Using this composition, titanium nitride can be effectively etched while avoiding etching of silicon oxide, resulting in a wider operating window and promising applications in semiconductor etching processes. Detailed Implementation

[0014] The advantages of the present invention will be further illustrated below with reference to specific embodiments.

[0015] It should be understood that all contents mentioned in this invention refer to mass percentages.

[0016] The chemical compositions of Examples 1-19 and Comparative Examples 1-5 were prepared according to the components and their contents in Table 1, with water as the balance.

[0017] The reagents and raw materials used in this invention are all commercially available.

[0018] Table 1. Components and their contents in the embodiments and comparative examples of the present invention.

[0019]

[0020]

[0021]

[0022]

[0023] To further test the performance of the above-mentioned chemical etching solution, the compositions of some examples and comparative examples were selected to perform etching tests on TiN and silicon oxide respectively. The specific test conditions are as follows:

[0024] Etching rate of metal The etching solution was placed in a reactor and heated to 50°C. The metal film was then placed in the solution and etched for 2 minutes. The etching rate was calculated by measuring the thickness change before and after etching using a four-probe resistance meter.

[0025] Etching rate of non-metals The etching solution was placed in a reactor and heated to 50°C. A silicon oxide film was then placed in the solution and etched for 5 minutes. The etching rate was calculated by measuring the thickness change before and after etching using a non-metallic film thickness meter.

[0026] The etch rate data obtained from the test are recorded in Table 2.

[0027] Table 2 shows the etching rates of some examples and comparative examples.

[0028]

[0029]

[0030] As shown in Table 2, the etching solution of the present invention has strong etching ability and can effectively etch TiN films, while exhibiting good compatibility with silicon oxide and a low etching rate. Comparison of Example 4 and Comparative Example 1 shows that without the addition of an oxidant, TiN cannot be effectively etched away, indicating that the etching of these films requires the direct participation of an oxidant, and the etching rate of silicon oxide is also low. Comparison of Example 4 and Comparative Example 2 shows that without the addition of an ammonium salt compound, the etching rate of TiN is significantly reduced, indicating that the etching of TiN films can be more effective in the presence of ammonium salts. Comparison of Example 4 and Comparative Example 3 shows that the absence of a surfactant also has a certain impact on the etching rate of TiN. Surfactants can reduce surface tension, effectively improve the contact between the etching solution and the film, thereby improving etching efficiency. Comparison of Example 4 and Comparative Example 4 shows that excessive oxidant will lead to a significant increase in the TiN etching rate, exceeding the control range, and may also affect etching uniformity. Comparison of Example 4 and Comparative Example 5 shows that with insufficient oxidant, the TiN etching rate is low and cannot meet the etching removal rate requirements.

[0031] In summary, the positive and progressive effects of this invention are as follows: it provides a titanium nitride etching composition, which includes an oxidant, a corrosion inhibitor, an ammonium salt, a surfactant, and water. Using the composition of this invention, titanium nitride can be effectively etched while avoiding etching of silicon oxide, resulting in a wider operating window and promising application prospects in semiconductor etching processes.

[0032] It should be noted that the embodiments of the present invention have better implementability and are not intended to limit the present invention in any way. Any person skilled in the art may use the above-disclosed technical content to change or modify it into equivalent effective embodiments. However, any modifications or equivalent changes and modifications made to the above embodiments based on the technical essence of the present invention without departing from the content of the technical solution of the present invention shall still fall within the scope of the technical solution of the present invention.

Claims

1. An etching composition, characterized in that, include: Oxides, corrosion inhibitors, ammonium salts, surfactants, and water.

2. The composition according to claim 1, characterized in that, The oxidant is selected from one or more of hydrogen peroxide, periodic acid, iodic acid, nitric acid, ammonium chlorate, ammonium iodate, ammonium perborate, ammonium perchlorate, ammonium periodate, ammonium persulfate, peracetic acid, perbenzoic acid, 1,4-benzoquinone, chlorobenzoquinone, and N-methylmorpholine N-oxide.

3. The composition according to claim 1, characterized in that, The corrosion inhibitor is selected from one or more of the following: 5-aminotetrazole, 1-hydroxy-benzotriazole, benzimidazole, pyrazole, benzotriazole, 1,2,4-triazole, 5-methyl-benzotriazole, 3-amino-1,2,4-triazole, 3-mercapto-1,2,4-triazole, 2-mercaptobenzimidazole, 2-mercaptobenzothiazole, 3-amino-5-mercapto-1,2,4-triazole, pentylenetetrazol, 5-phenyl-1H-tetrazole, 3-amino-5-methylthio-1H-1,2,4-triazole, benzothiazole, imidazole, indazole, and carbazole.

4. The composition according to claim 1, characterized in that, The ammonium salt is selected from one or more of ammonium phosphate, diammonium hydrogen phosphate, diammonium hydrogen phosphate, ammonium sulfate, ammonium sulfite, ammonium thiosulfate, ammonium thiocyanate, ammonium acetate, ammonium benzoate, ammonium citrate, ammonium hydrogen citrate, ammonium tartrate, ammonium succinate, and ammonium lactate.

5. The composition according to claim 1, characterized in that, The surfactant is selected from one or more of hexadecyltrimethylammonium bromide, hexadecyltrimethylammonium chloride, hexadecylpyridinium chloride monohydrate, benzylammonium chloride, benzyldimethyldodecylammonium chloride, benzyldimethylhexadecylammonium chloride, dodecyltrimethylammonium chloride, tetraheptylammonium bromide, tetra(decyl)ammonium bromide, tetradecyltrimethylammonium chloride, decyltrimethylammonium chloride, and benzyldimethylammonium chloride.

6. The composition according to claim 1, characterized in that, The oxidant has a mass percentage concentration of 5wt%-20wt%.

7. The composition according to claim 1, characterized in that, The corrosion inhibitor has a mass percentage concentration of 0.1wt%-2wt%.

8. The composition according to claim 1, characterized in that, The ammonium salt has a mass percentage concentration of 0.2 wt% to 5 wt%.

9. The composition according to claim 1, characterized in that, The surfactant has a mass percentage concentration of 0.1 wt% to 2 wt%.

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