| 摘要 |
PROBLEM TO BE SOLVED: To reduce defects of a semiconductor substrate. SOLUTION: An Al0.5Ga0.5N layer 27 is grown on a crystal substrate 1 to a thickness of 1.5μm. Here, trimethylgallium, trimethylaluminum, and ammonia are used as the material so that a mol supply ratio among Ga, Al, and N, is set so that Ga:Al:N=0.5:0.5:5,500. Then, a zigzag shape step of the height of 2μm is formed at the Al0.5Ga0.5N layer 27 through reactive ion etching. The step is deeper than the thickness of the Al0.5Ga0.5N layer 27, with a bottom part reaching the GaN substrate 1. An Al0.5Ga0.5N layer 28 is grown on the Al0.5Ga0.5N layer 27 to a depth of 30μm. |
