METHOD FOR FABRICATING A FREE-STANDING GROUP III NITRIDE SUBSTRATE

摘要

A method for fabricating a free-standing group III nitride substrate (100) comprises the steps of depositing a first group III nitride layer (102) on a growth substrate (101); forming a mechanically weakened sacrificial layer (110); depositing a second group III nitride layer (107) on the first group III nitride layer (102); and separating the second group III nitride layer (107) from the growth substrate (101) along the sacrificial layer (110). According to the present invention, the step of forming a mechanically weakened sacrificial layer (110) comprises forming openings (105) extending from the free surface of the first group III nitride layer (102) to the interfacial region (109) between the first group III nitride layer (102) and the growth substrate (101); and etching laterally, via the openings (105), the first group III nitride layer (102) in said interfacial region (109).