| 摘要 |
PURPOSE:To obtain a desired threshold voltage without decreasing the withstand voltage of a drain by a method wherein a semiconductor layer of a double layer with conductivity type varied alternately is formed on a substrate, and the semiconductor layer is treated by a prescribed method. CONSTITUTION:An N type epitaxial layer of required thickness is grown on the N type semiconductor substrate 1, and a P type Si layer 2 is formed by boron ion implantation and an N type Si layer 3 by arsenic ion implantation. Next, a V-groove reaching the substrate 1 is formed by anisotropic etching, and then the first oxide film 8 is formed on the surface. After etch-removal of this film 8, a gate oxide film 4 is grown to a required thickness. An oxide film 4 is bored at the part serving as a source, and a gate electrode 5 and a source electrode 6 are formed by evaporating Al over the entire surface; besides, a drain electrode 7 is formed on the substrate 1. An oxide film 4 is formed again after the film 8 is formed, so as to obtain a desired threshold voltage without decreasing the withstand voltage of the drain. |
