| 摘要 |
PROBLEM TO BE SOLVED: To provide an etching method of a wafer W including a SiN film and a SiOfilm on the surface in which etching processing with a high selective ratio of the SiOfilm to the SiN film can be performed.SOLUTION: In an etching method, process gas, for example, including NHgas and HF gas premixed in a gas supply part in advance is intermittently supplied to a processing container 1 after a wafer W including a SiN film 66 and a SiOfilm 69 on the surface is carried in the processing container 1. More specifically, the NHgas is intermittently supplied from a gas supply part to the processing container 1 while the HF gas is continuously supplied. The SiOfilm 69 can quickly react with the process gas including the HF gas and the NHgas, and the SiN film 66 has time lag to react with the process gas. The process gas is supplied by utilizing the time lag so that etching processing with a high selective ratio of the SiOfilm 69 to the SiN film 66 can be performed by repeatedly stopping supply of the process gas before reaction of the SiN film actively occurs. |
