| 摘要 |
PURPOSE:To assure the dielectric isolation of an insulating film into a flat one without unevenness whatever the distances are between mutual elements, between mutual diffusion layers, and between any element and any diffusion layer by providing a selective oxidation/separation region between mutual trench separation regions. CONSTITUTION:When only trench isolation is insufficient to separate one element from another, one diffusion layer from another, and any element from any diffusion layer, an optimum trench isolation region 2 adjacent to the elements 4, 5, 6 or the diffusion layer 8 is provided, and a selective oxidation and isolation region 3 is provided in a region where no trench region is existent, for formation of an isolation region. There is assured no bad surface having any unevenness and any stepped part whatever such a distance is, for example the distance is insufficiently buried permitting the occurrence of any recess part or it is buried in excess permitting the occurrence of any projecting part. Furthermore, there is no fear of any broken line being produced or of any cavity from being formed in a metal layer or an insulating film. |
