| 摘要 |
PROBLEM TO BE SOLVED: To provide a hetero-junction field-effect transistor, in which a source resistance and a drain resistance are reduced and which has excellent high-output characteristics and noise characteristics. SOLUTION: The hetero-junction field-effect transistor has a channel layer 12 successively formed on a substrate 10 and composed of In<SB>x</SB>Gal-<SB>x</SB>N (0≤<SB>x</SB>≤1), an electron supply layer 13 composed of Al<SB>y</SB>Gal-<SB>y</SB>N (0<<SB>y</SB>≤1), an intermediate layer 14 and an n-type cap layer 15 composed of GaN. A gate electrode 9 is formed while being brought into contact with the layer 13 and a source electrode 8S and a drain electrode 8D while being brought into contact with the layer 15 respectively, and the layer 14 contains an N-type impurity layer as at least one layer. Accordingly, since polarization negative charges generated between the layer 13 and the layer 15 can be offset by the ionized positive charges of the layer 14, a barrier to electrons is reduced, and the source resistance and the drain resistance can be lowered. COPYRIGHT: (C)2005,JPO&NCIPI
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