| 摘要 |
PURPOSE:To improve turn off performance and to permit high-frequency operation as well by a method wherein cathode N layer are formed by split and surface gate layers and buried gate layers are formed on a gate P layer by dispersion. CONSTITUTION:Cathode N2 layers are formed with broad rectangular shape and buried gate layers 4 formed low-resistance layers P2<++> are arranged in a P2 layer corresponding to the central sections of the N2 layers by diffusion. And surface gate layers 5 consisting of high-impurity layers are arranged on the surface of the P2 layer lain between each N2 layer by diffusion. Oxide films 6 are arranged on the surfaces of the layes 5 by riding on the N2 layers by diffusion and the short-circuits between the N2 layers and the layers 5 are prevented when a cathode electrode 7 is covered on the whole surfaces of the N2 layers. And a load current flowing to the N2 layers is turned off by the gate action at both the layers 4 and layers 5. In this composition, the width of effective cathode layers becomes narrow even if the width of the layers 4 is made narrower than the width of the N2 layers. Furthermore, the influence of autodope can be eliminated even if each interval Wg of the layers 4 is broaden. As a result, turn on time and turn off time can be shortened. |
