Patent ID: 9312165
Filing Date: 2016-04-12
CPC Classification: H01L

Claim Text:
1. A group III nitride composite substrate comprising a group III nitride film and a support substrate formed from a material different in chemical composition from said group III nitride film, said group III nitride film being joined to said support substrate in one of a direct manner and an indirect manner, said group III nitride film having a thickness of 10 μm or more, and a sheet resistance of a group III-nitride-film-side main surface of said group III nitride composite substrate being 200 Ω/sq or less, said group III-nitride-film-side main surface being a main surface common to said group III nitride composite substrate and said group III nitride film, wherein an area of a joined region joining said group III nitride film and said support substrate is 70% or more relative to an area of the main surface, and a non-joined region failing to join said group III nitride film and said support substrate includes at least one non-joined partial region, and said non-joined partial region is a small non-joined partial region having a maximum size in radial direction of less than 20 mm.