Patent ID: 8647901
Filing Date: 2014-02-11
Classification: C30B,H01L

Abstract:
1. A method of forming a nitride semiconductor layer, comprising the following steps: providing a substrate; forming a patterned epitaxy layer on a top surface of the substrate, wherein the patterned epitaxy layer comprises a plurality of pier structures and the plurality of pier structures each has a bar-like cross-sectional profile so that a portion of the top surface of the substrate is exposed, wherein the substrate comprises a different material than in the pier structures forming a protective layer on the patterned epitaxy layer to cover all sidewalls of the pier structures and the exposed portion of the top surface of the substrate, wherein the protective layer exposes a top surface of the plurality of pier structures; forming a nitride semiconductor layer over the patterned epitaxy layer connected to the nitride semiconductor layer through the pier structure, wherein the nitride semiconductor layer, the pier structures, and the protective layer together form a space exposing a bottom surface of the nitride semiconductor layer; using an electrolytic solution to remove a portion of the bottom surface of the nitride semiconductor layer and to weaken a connection point between the top surface of the plurality of pier structures and the nitride semiconductor layer; and separating the nitride semiconductor layer from the substrate through the connection point.