Method of forming semiconductor device and etching method

Abstract

This paper describes a method for forming a semiconductor device using a wet etching process, the process including a hard mask layer having at least one sidewall opening. A hydrophobic protective layer is formed on at least one sidewall of the hard mask layer. This hydrophobic protective layer contains a compound having at least one -NH2 group. Wet etching is performed on layers beneath the hard mask layer through the opening in the hard mask, and the hydrophobic protective layer prevents lateral etching of the next layer. Removing the hard mask layer with the hydrophobic protective layer yields a patterned layer.

Claims

1. A method for forming a semiconductor device, the method comprising: A metal layer is formed on a substrate; A hard mask layer is formed over the metal layer, the hard mask layer having an opening having at least one sidewall exposing the metal layer; a hydrophobic protective layer is formed on the at least one sidewall of the hard mask layer, the hydrophobic protective layer comprising a compound (1) (2) (3) having at least one of structure (1), structure (2) or structure (3) wherein A comprises an alkyl or ester group, X comprises at least one terminal NH2 group, BY is an antiwetting group, and CZ is a polar functional group, and in structure (1), each n is independently in the range of 0 to 50; the metal layer is wet-etched through the opening in the hard mask layer, the hydrophobic protective layer preventing lateral etching of the metal layer below the hard mask layer; and the hard mask layer having the hydrophobic protective layer is removed, leaving a patterned metal layer.

2. The method as described in claim 1, wherein a general formula of A is selected from the group consisting of -(CH2)m-, -C(=O)-O-(CH2)m-, -(CH2)mO-(CH2)mC(=O)O-CH2)m- and -(CH2)mOC(=O)-O-(CH2)m-, wherein each m in A is independently in a range from 0 to 10.

3. The method as described in claim 2, wherein a general formula of X is selected from the group consisting of , and , wherein each E is independently an alkyl, alkyl carbonyl or alkoxy group, each R group is independently H, OH, O(CH2)mCH3, NH2, straight-chain alkyl, isopropyl, tert-butyl, alkyl carbonyl or alkoxy group, and m is in the range of 1 to 10.

4. The method as described in claim 2, wherein X is selected from the group consisting of , , and , wherein each E is independently an alkyl, alkyl carbonyl or alkoxy group, each R group is independently H, OH, O(CH2)mCH3, NH2, straight-chain alkyl, isopropyl, tert-butyl, alkyl carbonyl or alkoxy group, and m is in the range from 0 to 10.

5. The method as described in claim 2, wherein X is of the general formula or, wherein each E is an alkyl, alkyl carbonyl or alkoxy group, each R group is independently H, OH, O(CH2)mCH3, NH2, straight-chain alkyl, isopropyl, tert-butyl, alkyl carbonyl or alkoxy group, and m is in the range from 0 to 10.

6. The method as described in claim 2, wherein X is of the general formula or, wherein each E is independently an alkyl, alkyl carbonyl or alkoxy group, each R group is independently H, OH, O(CH2)mCH3, NH2, straight-chain alkyl, isopropyl, tert-butyl, alkyl carbonyl or alkoxy group, and m is in the range from 0 to 10.

7. The method as described in claim 1, wherein Y is QR, where Q is –(CH2)m–, m is in the range of 1 to 10, and R is a straight-chain alkane, a branched-chain alkane, a monohalogenated straight-chain alkane, a monohalogenated branched-chain alkane, a phenyl or a monohalogenated phenyl.

8. The method as claimed in claim 1, wherein Z is an OR group and R is an alkyl group having a general formula -(CH2)m- or an alkoxy group having a general formula -(CH2)m-O-, -(CH2)m-C(=O)O-(CH2)m- or -(CH2)mOC(=O)-O-(CH2)m-, wherein each m is independently in a range from 0 to 10.

9. A method for forming a semiconductor device, the method comprising: A metal layer is formed on top of a substrate; A hard mask layer is formed over the metal layer, the hard mask layer having an opening having at least one sidewall exposing the metal layer; a hydrophobic protective layer is formed on the at least one sidewall of the hard mask layer, the hydrophobic protective layer comprising a compound having at least one -NH2 group; the metal layer is wet-etched through the opening in the hard mask layer, the hydrophobic protective layer preventing lateral etching of the metal layer below the hard mask layer; and the hard mask layer having the hydrophobic protective layer is removed, leaving a patterned metal layer.

10. An etching method, comprising: A patterned hard mask layer is formed over a substrate, the patterned hard mask layer having an opening having at least one sidewall exposing the substrate; A hydrophobic protective layer is formed on at least one sidewall of the patterned hard mask layer, the hydrophobic protective layer comprising a compound having at least one -NH2 group; and wet etching of the substrate through the opening in the patterned hard mask layer, the hydrophobic protective layer preventing a layer of lateral etching below the patterned hard mask layer, wherein the hydrophobic protective layer comprises a compound selected from any one of structure (1), structure (2) or structure (3) wherein A comprises an alkyl or an ester group, X comprises at least one terminal NH2 group, BY is an antiwetting group, and CZ is a polar functional group, and in structure (1), each n independently is in the range of 0 to 50.

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