| 摘要 |
PURPOSE:To eliminate the influence of a distortion in a transistor forming region by forming a selectively oxidized film in the same degree as the width of a groove on the bottom surface of the film. CONSTITUTION:Before a field region is formed, a groove is formed on a semiconductor substrate 3, with an Si3N4 film 6 as a mask a thermally oxidized film 7 is selectively formed on the same bottom of the groove after a field region is established in advance, the end 8 of lateral expansion of the film 7 is finished at the side wall of the groove, thereby intruding the field oxidized film directly under the surface Si3N4 film like a conventional LOCOS method, i.e., bird beak is entirely eliminated, and the decrease in the integration is prevented. When a (100) substrate is used as a substrate 3, a dislocation occurs in (111) plane on the low and deep part of the groove, i.e., the part isolated from the active region. Accordingly, the possibility of causing the dislocation to become the collecting level of carrier can be reduced. |
