| 摘要 |
PROBLEM TO BE SOLVED: To provide a field effect transistor hard to get damaged even if high voltage is applied. SOLUTION: The field effect transistor includes a substrate 1, a channel layer 3 and a barrier layer 4, a source electrode 6, a gate electrode 7 and a drain electrode 8 which are separately provided on the barrier layer 4 in this order. A first n-type impurity diffusion region 12 is provided immediately below the source electrode 6. A second n-type impurity diffusion region 13 is provided immediately below the drain electrode 8. A third n-type impurity diffusion region 15 is provided in the channel layer 3 under the second n-type impurity diffusion region and the channel layer 3 and the barrier layer 4 on the side of the gate electrode of the second n-type impurity diffusion region. The third n-type impurity diffusion region 15 has a lower n-type impurity concentration than that of the second n-type impurity diffusion region 13. Concentration of an electric field exceeding a breakdown strength is thus prevented from occurring in the barrier layer 4 and the channel layer 3 when voltage is applied between the gate electrode and the drain electrode. COPYRIGHT: (C)2011,JPO&INPIT |
