| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To improve RF characteristics by reducing a current collapse, and to obtain breakdown strength required for an amplifier for a portable-telephone base station. <P>SOLUTION: When an AlGaN layer 3 is grown and formed, the AlGaN layer (an i-AlGaN layer) 11 having an Al composition ratio of approximately 15% is grown on an i-GaN layer 2 in a film thickness of approximately 3 nm. The AlGaN layer (an n-AlGaN layer) 12, to which Si is doped in a concentration of approximately 2×10<SP>18</SP>/cm<SP>3</SP>and which has the Al composition ratio of approximately 15%, is grown in a film thickness of approximately 17 nm, and the AlGaN layer 3 composed of these two-layer structure is formed. <P>COPYRIGHT: (C)2005,JPO&NCIPI</p> |
