Patent ID: 8283254

Claim:
An etching method comprising: forming an antireflection coating layer on an etching target layer; forming a patterned resist film on the antireflection coating layer; and forming a desired pattern on the antireflection coating layer by introducing an etching gas including a CF 4 gas, a COS gas and an O 2 gas into a processing chamber and etching the antireflection coating layer by the etching gas while using the resist film as a mask, wherein the COS gas, at a certain flow rate, can become deposited on an etched surface of the antireflection coating layer and the O 2 gas is used to suppress the deposition of the COS gas, and a flow rate of the COS gas and a flow rate of the O 2 gas included in the etching gas are controlled proportionately to each other to balance the deposition of the COS gas and suppression of the deposition by the O 2 gas.