| 摘要 |
PURPOSE:To obtain a semiconductor device without any over and side etching by forming a mask on the surface where the stepped portion is removed of semiconductor material to be etched by the reactive/ion etching and by implanting impurity to the stepped portion of semiconductor material. CONSTITUTION:A gate oxide film 12 is deposited on an Si substrate 11, a P- doped polycrystalline Si gate electrode 13 is provided on the center thereof, the exposed area is surrounded by an oxide film 14 and a polycrystalline Si film 15 which is a film to be processed is deposited on the entire part including it. Then, a mask material of SiN film 17 is provided on the surface of film 15 which is extruded due to existence of electrode 13 and the film 15 which is not extruded, phosphorus P is doped to both extruded side surfaces being exposed, thereby a polycrystalline region 18 which reaches the film 12 is formed. Thereafter, the film 17 is removed, the one of region 18 is covered with the photo resist film 19, the other region 18 and the film 15 connected thereto are removed by the reactive ion etching. Thereby, a device having a highly accurate pattern can be obtained. |
