| 摘要 |
PURPOSE:To simplify and rationalize entire processes, by forming tapered parts at the periphery and the bottom part of a hole part of a trench by oxidizing process, which is also used for annealing. CONSTITUTION:After an oxide film 2 is formed on a semiconductor substrate 1, a window is provided by using photoresist 3. Then, the oxide film 3 is etched by wet etching. Thereafter, a trench 4 is formed by anisotropic etching. Then the resist 3 is removed. A groove is formed and impurities are introduced by means such as the introduction of impurities. Then speed-increasing oxidation is performed by thermal oxidation, and tapered parts are formed at the corner parts of the upper and lower parts in the trench 4. Finally, an oxide film 7 is etched away, and the 7 tapered trench 4 is obtained. Thus the entire processes are simplified and rationalized. |
