Patent ID: 7781245

Claim:
A method to form a semiconductor optical device, comprising: growing a stack on a semiconductor substrate, said stack including a plurality of semiconductor layers each made of group III-V compound semiconductor material; forming a silicon oxide film with a thickness greater than 2 μm on said stack by using an induction coupled plasma enhanced chemical vapor deposition apparatus to apply bias power to said semiconductor substrate; patterning said silicon oxide film; dry-etching said stack with said patterned silicon oxide film as an etching mask to form a semiconductor mesa structure; and growing a burying region made of group III-V compound semiconductor material in a growth temperature from 500 to 700° C. so as to bury said semiconductor mesa structure, wherein said silicon oxide film has a stress from −250 to −150 MPa at a room temperature, a stress greater than −200 MPa and less than 100 MPa in said growth temperature, and a positive temperature co-efficient of stress in a range from said room temperature to said growth temperature.