Patent ID: 9449844
Filing Date: 2016-09-20
CPC Classification: C23F,H01L

Claim Text:
1. An etching method for anisotropically etching a Cu film on a surface of a substrate, the method comprising: providing the substrate in a chamber and supplying a gas of an organic compound into the chamber while setting an inside of the chamber to a vacuum state, the organic compound selected from one of a carboxylic acid, aldehyde, and alcohol; irradiating an oxygen gas cluster ion beam to the Cu film; and oxidizing Cu of the Cu film to a copper oxide by oxygen gas cluster ions in the oxygen gas cluster ion beam and anisotropically etching the Cu film by a reaction between the copper oxide and the gas of the organic compound, wherein said supplying the gas of the organic compound and said irradiating the oxygen gas cluster ion beam are carried out simultaneously, and wherein said anisotropically etching the Cu film is performed in a state where a processing temperature of the substrate is controlled to be between zero degrees Celsius and a temperature lower than or equal to a boiling point of the organic compound, wherein the organic compound remains a gas during the etching process, wherein a partial pressure of the organic compound is controlled between 10