| 摘要 |
PURPOSE:To microscopically form the titled semiconductor device as well as to eliminate the parasitic effect generating thereon by a method wherein, when an isolation region is provided on the IC which contains a bipolar element, an insulating region is formed at the upper part of said isolation region and a P-N junction isolation region is formed at the lower part in such a manner that the width of the former is narrowered while that of the latter is widened. CONSTITUTION:A P type buried region 16 is formed on a P type substrate 1 using a solid-state source of diffusion such as boron, and an N type buried region 15 is provided surrounding said region 16 using a POCl3 liquid source of diffusion. Then, an N type layer 2 is epitaxially grown on the whole surface of the regions 15 and 16, a resist film 6 having the described aperture is provided on the layer 2 as a mask, and a plurality of grooves 7 entering into the region 16 are formed by performing an anisotropic etching. Subsequently, a plurality of layers 2 remaining in the grooves 7 are converted into SiO2 by performing a thermal oxidization and, at the same time, the insulating material 5 which will be turned to an isolation region is filled in the grooves 7 by cubically expanding said material 5. Through these procedures, the width of the insulation isolation region 5, to be provided at the upper part of the substrate 1, is narrowered and, at the same time, a field oxide film 4 is grown on the whole surface including said insulation isolation region 5. |
