Etching method, method of manufacturing article, and etching solution

Abstract

Disclosed herein is an etching solution containing hydrofluoric acid, an oxidizer, and an organic additive, wherein the organic additive is one or more compounds selected from polyethylene glycol, succinic acid, malic acid, dipropylamine, and alanine. This disclosure also includes an etching solution that removes a portion of a structure made of a semiconductor that is in contact with a catalyst layer made of a noble metal.

What is claimed is: 
     
         1 . An etching method comprising:
 forming a catalyst layer made of a noble metal on a structure made of a semiconductor; and   dipping the structure in an etching solution containing hydrofluoric acid, an oxidizer, and an organic additive to remove a portion of the structure that is in contact with the catalyst layer.   
     
     
         2 . The method according to  claim 1 , wherein molecules of the organic additive are polar molecules. 
     
     
         3 . The method according to  claim 1 , wherein the organic additive has a molecular weight of 60 to 20,000. 
     
     
         4 . The method according to  claim 1 , wherein the organic additive is one or more compounds selected from the group consisting of alcohol, carboxylic acid, hydroxy acid, amine, amino acid, an organic fluorine compound, and a chelating agent. 
     
     
         5 . The method according to  claim 1 , wherein the organic additive is one or more compounds selected from the group consisting of polyethylene glycol, succinic acid, malic acid, dipropylamine, and alanine. 
     
     
         6 . The method according to  claim 1 , wherein a concentration of the organic additive in the etching solution is 0.01 to 1 mass %. 
     
     
         7 . The method according to  claim 1 , wherein a concentration of hydrogen fluoride in the etching solution is 5 to 10 mol/L. 
     
     
         8 . The method according to  claim 1 , wherein a concentration of the oxidizer in the etching solution is 2 to 4 mol/L. 
     
     
         9 . The method according to  claim 1 , wherein an aggregate of particles each made of the noble metal is formed as the catalyst layer, and the structure is dipped in the etching solution to remove portions of the structure that are close to the particles and a portion of the structure that corresponds to a gaps between the particles. 
     
     
         10 . A method of manufacturing an article, comprising etching the structure by the etching method according to  claim 1 . 
     
     
         11 . The method according to  claim 10 , wherein the article is a semiconductor device. 
     
     
         12 . An etching solution containing hydrofluoric acid, an oxidizer, and an organic additive. 
     
     
         13 . The solution according to  claim 12 , wherein molecules of the organic additive are polar molecules. 
     
     
         14 . The solution according to  claim 12 , wherein the organic additive has a molecular weight of 60 to 20,000. 
     
     
         15 . The solution according to  claim 12 , wherein the organic additive is one or more compounds selected from the group consisting of alcohol, carboxylic acid, hydroxy acid, amine, amino acid, an organic fluorine compound, and a chelating agent. 
     
     
         16 . The solution according to  claim 12 , wherein the organic additive is one or more compounds selected from the group consisting of polyethylene glycol, succinic acid, malic acid, dipropylamine, and alanine. 
     
     
         17 . The solution according to  claim 12 , wherein a concentration of the organic additive is 0.01 to 1 mass %. 
     
     
         18 . The solution according to  claim 12 , wherein a concentration of hydrogen fluoride is 5 to 10 mol/L. 
     
     
         19 . The solution according to  claim 12 , wherein a concentration of the oxidizer is 2 to 4 mol/L.