Patent ID: 8357555

Claim:
A method for producing a semiconductor optical device, comprising the steps of: forming a semiconductor layer on a substrate; forming a non-silicon-containing resin layer on the semiconductor layer; forming a first pattern having a projection and a recess in the non-silicon-containing resin layer; forming a silicon-containing resin layer on the non-silicon-containing resin layer so as to cover the projection and the recess; etching the silicon-containing resin layer until a surface of the projection of the non-silicon-containing resin layer is exposed, the silicon-containing resin layer being left in the recess of the non-silicon-containing resin layer, the silicon-containing resin layer having a second pattern reverse to the first pattern; selectively etching the non-silicon-containing resin layer through the patterned silicon-containing resin layer by a reactive ion etching method employing a gas mixture containing CF 4 gas and O 2 gas, the non-silicon-containing resin layer having the second pattern; and etching the semiconductor layer through the patterned non-silicon-containing resin layer, wherein, in the step of selectively etching the non-silicon-containing resin layer, a side wall of the second pattern in the silicon-containing resin layer and the non-silicon-containing resin layer is formed, the silicon-containing resin layer and the non-silicon-containing resin layer are maintained at a temperature equal to or less than a freezing point of SiF 4 , and a protective layer containing SiF 4 is formed on the side wall of the second pattern in the silicon-containing resin layer and the non-silicon-containing resin layer.