Patent ID: 8778206

Claim:
A substrate processing method performed in a substrate processing apparatus including a processing chamber that accommodates therein a wafer, the substrate processing method comprising: a main etching process for etching a silicon layer formed on the wafer with plasma generated from a processing gas containing bromine to form a hole within the silicon layer; an ashing process for ashing the etched silicon layer with plasma generated from a processing gas containing oxygen; and a break-through etching process for etching the ashed silicon layer with plasma generated from a processing gas containing fluorine, wherein in the main etching process, silicon bromide is generated and deposited on an inner surface of the hole, so that the silicon bromide covers an entire inner surface of the hole, in the ashing process, an oxygen radical generated from the processing gas containing oxygen oxidizes the silicon bromide, so that the silicon bromide is changed into a silicon dioxide, and in the break-through etching process, a fluorine cation and a fluorine radical generated from the processing gas containing fluorine etch and remove the silicon dioxide.