| 摘要 |
PROBLEM TO BE SOLVED: To achieve normally-off of an HFET formed of a nitride-based III-V compound semiconductor. SOLUTION: On an Al<SB>0.2</SB>Ga<SB>0.8</SB>N barrier layer 4 laminated on a GaN channel layer 3, a gate electrode 7 is formed to fill the inside of a recess part 8 formed with random dimension and shape. When, in this way, an area where two-dimensional electron gas (2DEG) occurs is reduced and the overall 2DEG density is lowered, normally-off can be achieved. In this process, when a dislocation part (a crystal defect part) in the AlGaN barrier layer 4 is selectively subjected to wet etching, the recess part 8 with the random dimension and shape is formed without causing damage, and deterioration of channel mobility is suppressed to prevent increase in on-state resistance in a channel region. COPYRIGHT: (C)2010,JPO&INPIT |
