| 摘要 |
PURPOSE:To enable to enhance the density of an element by forming an oxidized film isolation with an ultrafine width and flat surface, thereby removing the adverse influence to the reliability and electric characteristics of a semiconductor device. CONSTITUTION:The first SiO2 film 2 and the first Si3N4 film 3 are formed on a silicon substrate 1, a recess 4 is formed by an anisotropic etching on the surface of a semiconductor substrate, and insulating films 12, 13 are formed on the overall surface of the substrate 1 including the recess surface. A window 15 having a width narrower than the bottom of the recess is opened at the films on the bottom of the recess. Then, with the insulating films as masks the surface of the semiconductor substrate in the bottom of the recess is formed in a smooth curved surface. The exposed surface 16 of the substrate is oxidized, an oxidized film 5 is formed, thereafter the films 13 and 3 are removed, and an oxidized isolation 5 having a flat surface is completed. |
