Patent ID: 9524877
Filing Date: 2016-12-20
CPC Classification: H01L

Claim Text:
1. A plasma-less dry etching method for etching a silicon layer as a processing target in a processing room, comprising: supplying an iodine heptafluoride-containing etching gas from a gas supply source at a supply pressure of 66 kPa to 0.5 MPa; evacuating the processing room to an internal pressure lower than the supply pressure of the etching gas; and, while maintaining the etching gas at the supply pressure, introducing the etching gas into the evacuated processing room so as to etch the silicon layer by the etching gas, wherein the ratio Ps/Pn between the supply pressure (Ps) of the etching gas and the internal pressure (Pn) of the processing room is in a range of 20 to 1×10 wherein plasma excitation is not required.