Method of manufacturing a distributed feedback type semiconductor device

Abstract From the Canadian patent

A method of manufacturing a distributed feedback type semiconductor laser comprises a first cladding layer an, active layer disposed on the first cladding layer a guiding, layer disposed on the active layer and a second cladding layer disposed on the guiding layer respectively in which a, grating is disposed on the guiding layer wherein the method, comprises, a step of forming a predetermined material layer on the guiding layer, a step of selectively etching the material layer and the guiding layer until the guiding layer is at least partially exposed thereby forming undulation substantially in a trigonal waveform to the surface of the material layer and the guiding layer, and a step of …