| 摘要 |
PURPOSE:To improve the remaining accuracy of a polySi layer and to facilitate the production of a memory cell by a method wherein the termination of the etching to be performed on the polySi layer in a trench is detected using the polySi layer remained on a semiconductor substrate. CONSTITUTION:A trench 12 and an oxide film 13 are formed in and on a semiconductor substrate 11 and when a polySi layer 14 is laminated in a prescribed thickness and selectively etched until the film 13 is exposed, the layer 14 is remained in the trench 12 up to the position of the surface of the substrate 11. Then, a photo resist layer 15 is removed, the whole surface of the substrate 11 is subjected to anisotropic etching and when the film 13 on the surface of the substrate 11 is exposed, the termination of the etching is detected and the etching ends. Thereby, the layer 14 in the trench 12 is etched by the thickness of the layer 14 remained on the substrate 11 and the layer 14 to act as an electrode for the capacity of a memory cell is remained with good accuracy. |
