| 摘要 |
<P>PROBLEM TO BE SOLVED: To achieve a highly reliable compound semiconductor device having a stable threshold with a small variation and achieving a sufficient high breakdown voltage even when a gate recess structure is introduced to enable a normally-off operation. <P>SOLUTION: An intermediate layer 5 made of i-AlN is formed between an electron transit layer 3 and an electron supply layer 4, and an opening 11a is formed at a position on a cap structure 7, the position where a gate electrode is to be formed, using the intermediate layer 5 as an etching stopper. Then, an opening 11b is formed at a position positionally aligned with the opening 11a of the intermediate layer 5 by wet etching using a hot phosphoric acid, and a gate electrode 13 is formed so that the lower portion thereof fills an opening 11 comprising the openings 11a and 11b via a gate insulating film 12 and the upper portion thereof projects above the cap structure 7. <P>COPYRIGHT: (C)2011,JPO&INPIT |
