| 摘要 |
PROBLEM TO BE SOLVED: To provide a semiconductor device wherein a high-quality nitride semiconductor crystal layer having a large thickness can be obtained in a state of reduced internal strain with a good reproducibility. SOLUTION: The semiconductor device has a stacked structure wherein an AlN layer (having a thickness of 150 nm) as a nucleation layer 2, a compositionally graded In<SB>1-X</SB>Al<SB>X</SB>N layer as a buffer layer 3 (having a thickness of 210 nm, and the mole fraction 1-X of In varying from 0.17 to 0.1 from top to bottom at a rate of change being 0.01 per 30 nm of thickness); a GaN layer (having a thickness of 1,000 nm); and AlGaN barrier layer (having a thickness of 25 nm and a mole fraction of Al being 0.25) as a nitride semiconductor crystal layer 4 are stacked in order on an Si substrate as a substrate 1. COPYRIGHT: (C)2008,JPO&INPIT
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