| 摘要 |
PURPOSE:To flatten the isolation region between elements and to attain high integration without birdbeak by providing a groove reaching a substrate at an epitaxial layer wherein the surface of poly crystal is selectively oxidized after shallowly filling poly crystal Si in the groove through an oxide film. CONSTITUTION:A mask consisting of an oxide film 3 and a nitride film 4 is formed on the surface of an Si substrate 1 consisting of a (100) plane providing a opposite conductive type epitaxial layer 2 and a V-shaped groove 5 reaching the substrate is formed at an isolation region between elements by anisotropic etching, for example. Next, after forming an oxide film 6 on the surface of the groove 5, a poly Si layer 7 is piled on the whole surface of the film 6 with about twice the depth of the groove 5 in thickness. Next, chemical polishing is applied to the surface of the poly Si to leave the layer 7 about half the depth of the groove in thickness in the groove 5. Then, after forming an oxide film 10 on the surface of the layer 7 by selective oxidization by consisting the films 3, 4 as masks, the films 4, 3 are removed by etching. In this way, a semiconductor device can be composed by flattening the isolation region between elements and also by eliminating a birdbeak section. |
