Method for etching oxide film in plasma etching system

Claim 1

A method for etching an oxide film in a plasma etching system, wherein the oxide film is etched using a mixture gas consisting essentially of: a first gas which is a main etching source gas; a second gas for adjusting a profile angle of an etching object; and a third gas for providing a high selectivity of the oxide film to materials other than the oxide film, wherein the first, second and third gases are fluorocarbons.

Claim 2

A method for etching an oxide film in a plasma etching system, wherein the oxide film is etched using a mixture gas consisting essentially of: a first gas which is a main etching source gas; a second gas for adjusting a profile angle of an etching object; and a third gas for providing a high selectivity of the oxide film to materials other than the oxide film, wherein the first, second and third gases are fluorocarbons.

Claim 13

A method for etching an oxide film in a plasma etching system, comprising the steps of: forming an oxide film on a substrate; forming a mask on the oxide film; and etching portions of the oxide film unmasked by the mask using a mixture gas consisting essentially of CHF 3 /C 2 HF 5 /C 4 F 8 .

Claim 14

A method for etching an oxide film in a plasma etching system, comprising the steps of: forming an oxide film on a substrate; forming a mask on the oxide film; and etching portions of the oxide film unmasked by the mask using a mixture gas consisting essentially of CHF 3 /C 2 HF 5 /C 4 F 8 .

Claim 15

A method for etching an oxide film in a plasma etching system, comprising the steps of: forming a gate electrode and a cap gate insulating film on a semiconductor substrate; forming a source region and a drain region in the semiconductor substrate on both sides of the gate electrode; forming a sidewall insulating films at sides of the gate electrode; forming an oxide film on an entire surface of the substrate including the gate electrode and the sidewall insulating films; forming a photoresist film on the oxide film such that a portion of the oxide film over the drain region is exposed; and selectively etching the portion of the oxide film using a mixture gas consisting essentially of CHF 3 /C 2 HF 5 /C 4 F 8 .

Claim 16

A method for etching an oxide film in a plasma etching system, comprising the steps of: forming a gate electrode and a cap gate insulating film on a semiconductor substrate; forming a source region and a drain region in the semiconductor substrate on both sides of the gate electrode; forming a sidewall insulating films at sides of the gate electrode; forming an oxide film on an entire surface of the substrate including the gate electrode and the sidewall insulating films; forming a photoresist film on the oxide film such that a portion of the oxide film over the drain region is exposed; and selectively etching the portion of the oxide film using a mixture gas consisting essentially of CHF 3 /C 2 HF 5 /C 4 F 8 .