Patent ID: 7981591

Claim:
A method of forming a grating profile in a semiconductor laser structure comprising: providing a semiconductor wafer comprising a wafer substrate, an etch stop layer disposed over the wafer substrate, a grating layer disposed over the etch stop layer, an etch mask layer disposed over the grating layer, and a photoresist layer disposed over the etch mask layer, wherein the wafer substrate comprises an active lasing region; forming a photoresist grating pattern in the photoresist layer; transferring the photoresist grating pattern into the grating layer via dry etching; removing the photoresist layer; performing a first selective wet etching on the grating layer to form the grating profile in the grating layer, wherein the placement of the grating layer between the etch mask layer and the etch stop layer controls the first selective wet etching; performing a second selective wet etching after the first selective wet etching to remove the etch mask layer without altering the grating profile of the grating layer; and regrowing an upper cladding layer over the grating layer to produce the semiconductor laser structure.