Patent ID: 9123637
Filing Date: 2015-09-01
Classification: H01L

Abstract:
1. A semiconductor epitaxial structure, comprising: a nitride nucleation layer formed on a substrate including silicon, sapphire, patterned sapphire substrate (PSS) or silicon carbide; a nitride layer including a first nitride layer and a second nitride layer formed on the nitride nucleation layer; and a multi-layer structure formed between the first nitride layer and the second nitride layer, wherein the multi-layer structure comprises a first intermediate layer and a second intermediate layer formed on the first intermediate layer, the first intermediate layer comprises AlGaN, the second intermediate layer comprises AlGaN or aluminium nitride, and the average composition of Al in the first intermediate layer is less than that in the second intermediate layer; and wherein a thickness of the second intermediate layer is greater than a critical thickness of the second intermediate layer and a growth stress in the second intermediate layer is partially or fully relaxed.