Chemical composition for removing etching residues

Abstract

The invention provides a chemical composition for removing etching residues, which comprises organic ammonium, a corrosion inhibitor, an organic solvent, an inhibitor, hydroxylamine and deionized water, the organic ammonium is selected from one or more of choline hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutyl ammonium hydroxide, tributyl methylammonium hydroxide, benzyl trimethyl ammonium hydroxide, ethyl trimethyl ammonium hydroxide, diethyl dimethyl ammonium hydroxide and tris (2-ethoxyl) methylammonium hydroxide, and the organic ammonium is selected from one or more of choline hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutyl ammonium hydroxide, tributyl methylammonium hydroxide, benzyl trimethyl ammonium hydroxide, ethyl trimethyl ammonium hydroxide, diethyl dimethyl ammonium hydroxide and tris (2-ethoxyl) methylammonium hydroxide; the inhibitor is selected from one or more of fructose, galactose, lactose, maltose, glucose, ascorbic acid, hydroxylamine sulfate and ethanol hydrazine. Compared with the prior art, the chemical composition for removing the etching residues can effectively remove the residues after plasma etching, meanwhile, etching of AlCu, TiN / Ti and silicon oxide is avoided, an operation window is large, and the chemical composition has good application prospects in the semiconductor etching process.

Description

Technical Field

[0001] The present invention relates to the field of etching technology, and in particular, to a chemical composition for removing etching residues. Background Art

[0002] In the manufacturing process of semiconductor devices, many steps in the manufacturing and packaging processes of integrated circuit chips are etching processes. Therefore, in recent years, many different types of etching methods have been developed to remove corresponding materials, sometimes removing materials in selective areas. These etching methods are extremely crucial and decisive steps for etching different layers that make up the final integrated circuit chip. These methods have been applied to varying degrees.

[0003] Positive photoresist has been widely used as a mask material to form patterns and vias on a substrate, so that the patterns can then be etched, and thus patterns are formed in the substrate. The final step in manufacturing the substrate includes removing the unexposed photoresist material from the substrate. However, methods such as plasma etching and reactive ion etching used to form patterns and vias in the substrate make the photoresist material more difficult to remove. For example, in the production of multi-layer wiring at the back end of the wire interconnection of logic devices, reactive ion etching is used to generate vias through the interlayer dielectric, so that silicon, silicide, or metal wiring on one horizontal plane provides contact with the wiring on the next horizontal plane. These vias usually expose Al, AlCu, Cu, Ti, TiN, Ta, TaN, silicon, or silicide, etc. The residues of the complex mixture generated by the reactive ion etching method may include re-sputtered oxides and may also contain a small amount of organic materials in the photoresist used to form the vias. Similarly, when manufacturing conductive lines of Al, Cu, and their alloys, there will be etching residues on the conductive lines, and these residues must be removed. The residues are difficult to remove, and at the same time, selectivity is required for other exposed dielectrics and metals, etc., which poses a challenge to the performance of the removal composition.

[0004] Therefore, there is a need to provide a selective method for removing photoresist and etching residues, which has higher selectivity for etching residues compared to the removal of metals, silicon, silicides, and re-sputtered oxides that may also be exposed to the cleaning composition. Summary of the Invention

[0005] In order to provide a chemical composition that can effectively remove residues after plasma etching while avoiding etching of AlCu, TiN / Ti, and silicon oxide by the chemical composition for removing etching residues, the object of the present invention is to provide a chemical composition for removing etching residues, including: organic ammonium, corrosion inhibitor, organic solvent, inhibitor, hydroxylamine, and deionized water;

[0006] The organic ammonium is selected from one or more of choline hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, tributylmethylammonium hydroxide, benzyltrimethylammonium hydroxide, ethyltrimethylammonium hydroxide, diethyldimethylammonium hydroxide, and tris(2-hydroxyethyl)methylammonium hydroxide;

[0007] The inhibitor is selected from one or more of fructose, galactose, lactose, maltose, glucose, ascorbic acid, hydroxylamine sulfate, and ethanol hydrazine.

[0008] Preferably, the mass percentage content of the organic ammonium is 0.1 wt% - 20 wt%.

[0009] Preferably, the corrosion inhibitor is a compound with the chemical formula R1(R2,R3,R4,R5,R6,R7), where R1 is a phenyl group, and R2 - R7 are each independently selected from H, an alkyl group, a hydroxyl group, or a carboxyl group.

[0010] Preferably, the mass percentage content of the corrosion inhibitor is 0.1 wt% - 8 wt%.

[0011] Preferably, the organic solvent is selected from one or more of isopropyl alcohol, butanol, butylene carbonate, propylene carbonate, diethylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether (DPM), dipropylene glycol dimethyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether, propylene glycol phenyl ether, N-methylpyrrolidone, N-ethylpyrrolidone, N,N-dimethylacetamide, and dimethyl sulfoxide;

[0012] The mass percentage content of the organic solvent is 5 wt% - 30 wt%.

[0013] Preferably, the mass percentage content of the hydroxylamine is 0.5% - 5 wt%.

[0014] Preferably, the mass percentage content of the inhibitor is 1% - 10 wt%.

[0015] Compared with the prior art, the chemical composition for removing etching residues in the present invention can effectively remove the residues after plasma etching, while avoiding etching of AlCu, TiN / Ti, and silicon oxide, has a large operation window, and has good application prospects in semiconductor etching processes. Detailed Embodiments

[0016] The advantages of the present invention are further elaborated below in conjunction with specific embodiments.

[0017] Prepare the chemical compositions for removing etching residues of Examples 1 - 18 and Comparative Examples 1 - 5 according to the formulations shown in Table 1. The balance is water. Among them, the contents all refer to mass percentage contents.

[0018] Table 1 Components and contents of the chemical composition for removing etching residues in Examples 1-18 and Comparative Examples 1-5

[0019]

[0020]

[0021]

[0022] To further test the performance of the above chemical composition for removing etching residues, the compositions of some examples and Comparative Examples 1-5 were selected to conduct etching tests on AlCu, TiN, and silicon oxide respectively. The specific test conditions are as follows:

[0023] Etching rate of AlCu and TiN The etching composition solution was placed in a reactor and heated to 50°C. Then the AlCu film was placed in it for etching for 3 minutes, and the etching rate was calculated by measuring the thickness change before and after etching with a four-probe resistance tester.

[0024] Etching rate of silicon oxide The etching composition solution was placed in a reactor and heated to 50°C. Then the silicon oxide film was placed in it for etching for 3 minutes, and the etching rate was calculated by measuring the thickness change before and after etching with a non-metallic film thickness tester.

[0025] The obtained etching rate data are recorded in Table 2.

[0026] Table 2 Etching test data of some examples and Comparative Examples 1-6

[0027]

[0028] Note: Removal effect of residues after etching: ◎ Basically removed completely; ○ A small amount of residue; △ More residue; × A large amount of residue

[0029] It can be seen from Table 2 that the cleaning solution of the present invention has strong cleaning ability, can effectively remove the residues after etching, and has only a small corrosion rate for AlCu, silicon oxide and titanium nitride. The comparison between Example 2 and Comparative Example 1 shows that without adding organic ammonium, the residues after etching cannot be removed, and at the same time, the etching rate of AlCu also decreases. The comparison between Example 2 and Comparative Example 2 shows that without adding a corrosion inhibitor, the etching rate of AlCu is greatly affected, the rate increases significantly, and at the same time, the removal of residues is also affected to a certain extent. The comparison between Example 2 and Comparative Example 3 shows that without adding a solvent, the removal effect of the residues after etching is also affected to a certain extent. The comparison between Example 2 and Comparative Example 4 shows that without adding an inhibitor, it has a certain impact on inhibiting the etching of AlCu, and the etching rate increases. The comparison between Example 2 and Comparative Example 5 shows that without adding hydroxylamine, the residues after etching cannot be effectively removed, and the etching rate of AlCu will increase to a certain extent. The comparison between Example 2 and Comparative Example 6 shows that adding other alkalis and their content exceeding 20% will greatly increase the corrosion rate of AlCu, which is not conducive to the selective removal effect of the composition on the residues after etching and causes greater corrosion to the metal.

[0030] In summary, the positive and progressive effects of the present invention are as follows: A composition for wet removal of residues after etching is provided, and the composition may include an organic base, a corrosion inhibitor, an organic solvent, a polyol, deionized water, etc. Using the chemical composition for removing residues after etching of the present invention can effectively remove the residues after etching, while avoiding etching of AlCu, TiN / Ti and silicon oxide, and has a large operating window, and has good application prospects in the semiconductor etching process.

[0031] It should be noted that the embodiments of the present invention have better implementability and are not any form of limitation to the present invention. Any person skilled in the art may use the disclosed technical content to change or modify it into an equivalent effective embodiment. However, as long as it does not depart from the technical content of the technical solution of the present invention, any modification, equivalent change or modification made to the above embodiments according to the technical essence of the present invention still belongs to the scope of the technical solution of the present invention.

Claims

1. A chemical composition for removing etching residues, characterized in that, Comprising: Organic ammonium, corrosion inhibitor, organic solvent, inhibitor, hydroxylamine and deionized water; The organic ammonium is selected from one or more of choline hydroxide, tetramethylammonium hydroxide, tetraethylammonium hydroxide, tetrapropylammonium hydroxide, tetrabutylammonium hydroxide, tributylmethylammonium hydroxide, benzyltrimethylammonium hydroxide, ethyltrimethylammonium hydroxide, diethyldimethylammonium hydroxide, tris(2-hydroxyethyl)methylammonium hydroxide; The inhibitor is selected from one or more of fructose, galactose, lactose, maltose, glucose, ascorbic acid, hydroxylamine sulfate, ethanol hydrazine.

2. The chemical composition for removing etching residues according to claim 1, wherein, The mass percentage content of the organic ammonium is 0.1 wt% - 20 wt%.

3. The chemical composition for removing etching residues according to claim 1, wherein, The corrosion inhibitor is a compound with the chemical formula R1(R2,R3,R4,R5,R6,R7), R1 is a phenyl group, and R2 - R7 are each independently selected from H, alkyl group, hydroxyl group or carboxyl group.

4. The chemical composition for removing etching residues according to claim 1, wherein, The mass percentage content of the corrosion inhibitor is 0.1 wt% - 8 wt%.

5. The chemical composition for removing etching residues according to claim 1, wherein, The organic solvent is selected from one or more of isopropanol, butanol, butylene carbonate, propylene carbonate, diethylene glycol monomethyl ether, ethylene glycol monobutyl ether, diethylene glycol monobutyl ether, propylene glycol methyl ether, dipropylene glycol methyl ether (DPM), dipropylene glycol dimethyl ether, propylene glycol n-butyl ether, dipropylene glycol n-butyl ether, tripropylene glycol n-butyl ether, propylene glycol phenyl ether, N-methylpyrrolidone, N-ethylpyrrolidone, N,N-dimethylacetamide, dimethyl sulfoxide; The mass percentage content of the organic solvent is 5 wt% - 30 wt%.

6. The chemical composition for removing etching residues according to claim 1, wherein, The mass percentage content of the hydroxylamine is 0.5% - 5 wt%.

7. The chemical composition for removing etching residues according to claim 1, wherein, The mass percentage content of the inhibitor is 1% - 10 wt%.

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