| 摘要 |
PURPOSE:To obtain a vertical MOSFET in such the structure that no breakdown is generated by brakedown current by a method wherein oxide films, a polycrystalline silicon film and a gate electrode are formed on the substrate and after a film is evaporated on the step part of the end part of the gate electrode, an impurity is diffused through the gap part of the film evaporated, which is generated in the step part, and the source region is formed. CONSTITUTION:An oxide film 22, a phosphorus-added polycrystalline silicon film 23 and an oxide film 24 are made to grow on an N type Si substrate 21, and after that, an etching is continuously performed on the oxide film 24, the silicon film 23 and the oxide film 22 and the etched end surface only of the polycrystalline silicon film 23 is oxidized. Moreover, boron is ion-implanted in the substrate, a back gate region 25 is formed, Al is evaporated from the normal direction to the substrate and an Al layer 26, which is thinly evaporated on the step part of the end part of the gate electrode, is formed. When an etching is performed lightly on the Al layer 26 using phosphoric water solution and so forth, a gap 27, from where the Si substrate 21 is made to expose, is formed in the step part. As<+> ions are implanted through this gap, an N<+> type region 28 is formed and after the Al layer 26 is removed, annealing LAs<+> ions are activated and an Al layer 29 for wiring is formed to use as the source electrode. |
