| 摘要 |
PROBLEM TO BE SOLVED: To realize a vertical field-effect transistor comprising an MES-type structure, dielectric strength of which is high and which can be operated by a large current by effectively, using a GaN compound semiconductor. SOLUTION: The vertical field-effect transistor is realized with a source electrode being formed in the upper part of a GaN semiconductor multilayered film layer and with the drain electrode being formed in its lower part. An n+ GaN layer 8 (a fourth semiconductor layer) which is to be used as a source region is formed, via an undoped i-GaN layer 5 (a second semiconductor layer), a p+ GaN layer 6 and a p- GaN layer 7 (a third semiconductor layer) in a low-carrier-concentration n- GaN layer 4 (a first semiconductor layer), which forms a current passage between the source electrode and the drain electrode. An n+ GaN layer 9 (a fifth semiconductor layer) is formed thin in the upper part of the n- GaN layer 4, directly under a gate electrode. |
