| 摘要 |
PURPOSE:To provide a field effect transistor (FET) having desired crystal and impurity density by forming a gate columnar semiconductor region having a depth reaching a substrate in an n-type semiconductor layer on the substrate. CONSTITUTION:An n-type semiconductor layer 12 is formed on a semi-insulating substrate 1, and source and drain electrodes 13 and 14 are formed in an ohmic junction on the layer 12. Then, p-type columnar gate semicnductor regions 15a-15d are vertically extended to the surface of the layer 12 having a depth reaching the substrate 1. Thereafter, a gate electrode 16 is formed in an ohmic junction with the regions 15a-15d. |
