| 摘要 |
PURPOSE:To increase a threshold voltage and to improve the characteristics of an element, by patterning and forming a first semiconductor layer in the vicinity of the boundary between an element region and a field region through a first insulating film. CONSTITUTION:Corner parts 411 of a device forming region are not inverted by an insulating film 403, a multicrystal silicon film 404, and a gate insulating film 405, which are formed on the region. That is, a channel is not formed. Therefore a reverse channel effect does not appear and a kinky phenomenon does not appear. Thus the excellent MOSFET characteristics are obtained. Furthermore, since the polycrystal film 404 is present, reduction in a field film 402, which is embedded in the vicinity of the corner parts, due to the following various etching treating processes, is hard to occur (etching speed in the vicinity of the corner parts is especially faster than that at the flat part in the field region, a concave part is formed, and high reliability is feared to be impaired). |
