Solution for removal of residue after semiconductor dry processing, and residue removal method using the same

Abstract

Disclosed is a solution for removing a residue after a dry processing, which can prevent the cracking or roughening of a Cu surface which cannot be overcome by a conventional liquid polymer stripper, which can prevent the oxidation of a Cu surface, and which contains a surface-protecting agent. Also disclosed is a method for producing a semiconductor device by using the solution. Specifically disclosed is a solution for removing a residue remaining on a semiconductor substrate after dry etching and / or ashing, which comprises: a Cu surface-protecting agent comprising at least one compound selected from the group consisting of (1) a compound which has, as a basic skeleton, a 5-membered heterocyclic aromatic compound having a structure represented by the formula: =N-NH- (provided that one having three contiguous N atoms is excluded) and which shows a pH value of 7 or less in the form of an aqueous solution (10 ppm, 23 DEG C); (2) a compound which has, as a basic skeleton, a 5-membered heterocyclic compound having a structure represented by the formula: -N=C(SH)-X- [wherein X represents NH, O or S] and which shows a pH value of 7 or less in the form of an aqueous solution (10 ppm, 23 DEG C) and (3) a compound which has, as a basic skeleton, a 6-membered heterocyclic aromatic compound having at least one nitrogen atom (N) and which shows a pH value of 7 or more in the form of an aqueous solution (10 ppm, 23 DEG C); a compound capable of forming a complex or chelate in coordination with Cu (copper); and water. The solution has a pH value ranging from 4 to 9.

Description

technical field [0001] The present invention relates to a chemical solution for removing residues formed during dry etching and / or ashing in a manufacturing process of a semiconductor device, and a method of manufacturing a semiconductor device using the chemical solution to remove these residues. In particular, it relates to a residue removal liquid used in the manufacture of a Cu / Low-k multilayer wiring structure. Background technique [0002] Conventionally, Al or an Al alloy has been used as a wiring material, and SiO has been used as an interlayer insulating film. 2 Al / SiO film 2 A semiconductor device with a multilayer wiring structure is produced as a core. In recent years, in order to reduce the interconnect delay (interconnect delay) caused by the miniaturization of semiconductor devices, a low-resistance interconnect material Cu (copper) and an interlayer insulating film Low-k film with a small capacitance between interconnects are often produced. (Low dielectri...

AI Technical Summary

Problems solved by technology

However, at this concentration, the pH of the oxalic acid aqueous solution is 1.5 to 3. Since this pH is lower than the pKa=pH (=3.82) of oxalic acid, the effect of preventing Cu oxidation is poor, and the surface of Cu is prone to cracks and roughness.

[0014] Therefore, it is desired to develop a residue removal solution after a dry process that prevents the oxidation of the Cu surface and also has the function of preventing the cracking and roughening of the Cu surface, but such a product has not been developed so far.

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