Patent ID: 9613823
Date: 2017-04-04
CPC Classifications: H01L

Claim:
1. An etching method, comprising: disposing a target substrate within a chamber, the target substrate having a first silicon oxide film formed on a surface of the target substrate by a chemical vapor deposition method or an atomic layer deposition method, a second silicon oxide film that includes a thermally-oxidized film and a silicon nitride film, and the second silicon oxide film and the silicon nitride being formed adjacent to the first silicon oxide film; and supplying an HF gas and an alcohol gas or water vapor into the chamber to selectively etch the first silicon oxide film with respect to the second silicon oxide film and the silicon nitride film, wherein, in the etching, an internal pressure of the chamber is set to fall within a range from 66.7 to 1333.3 Pa, and wherein, a volume ratio of the alcohol gas or the water vapor to the total volume of the HF gas+the alcohol gas or the water vapor is set to fall within a range from 3 to 50 volume % when performing the etching.