Patent ID: 7265058

Claim:
A method of manufacturing a semiconductor device in patterning of a conductive film and a thin dielectric film, comprising the steps of: a first etching step of carrying out anisotropic etching until most of the conductive film in a flat portion of the dielectric film disappears, the first etching step using a mixed gas including O 2 ; and a second etching step of increasing a selective ratio to the dielectric film, by increasing the flow ratio of O 2 to etch the conductive film in a first desired portion of the dielectric film in a state in which the conductive film is caused to remain in a second desired portion of the dielectric film such that a thickness of the dielectric film provided under a grain boundary between the conductive film and the dielectric film provides a pattern to prevent oxidation species associated with the mixed gas from reaching an interface with a substrate after the first etching step; wherein the second etching step uses a hydrogen bromide (HBr)/Cl 2 /O 2 plasma, wherein the second etching step is executed at an in-chamber pressure of 2 mTorr or less, and further wherein the conductive film is a silicon type conductive film.