Patent ID: 8212288
Filing Date: 2012-07-03
Classification: H01L

Abstract:
1. A compound semiconductor substrate, arranged such that a multilayer buffer layer in which Al x Ga 1-x N single crystal layers (0.6≦X≦1.0) containing carbon from 1×10 18 atoms/cm 3 to 1×10 21 atoms/cm 3 and Al y Ga 1-y N single crystal layers (0≦y≦0.5) containing carbon from 1×10 17 atoms/cm 3 to 1×10 21 atoms/cm 3 are alternately and repeatedly stacked, and a nitride active layer comprising an electron transport layer having a carbon concentration of 5×10 17 atoms/cm 3 or less and an electron supply layer are deposited successively on a Si single crystal substrate, wherein a carbon concentration of said Al