| 摘要 |
PURPOSE:To make the surface of an isolation region flat, by making an aperture on an insulative film formed on the surface of a semiconductor substrate to expose a part of the substrate on which an U-shaped groove is formed, and providing in the groove a dielectric isolation region on a channel-cut regions as underlay, while the aperture on the insulative film is widened. CONSTITUTION:On the surface of Si substrate 1, a SiO2 film 2 and a Si3N4 film 3 are formed by lamination. An U-shaped groove 6 corresponding to a dielectric isolation region to be formed is formed by etching. In the peripheral bottom part of the groove, a channel-cut region CC is formed by ion implantation. A film 2 surrounding the surface of the groove 6 is retreated by wet etching applying hydrofluoric acid, etc. to form a side etching part 7, and a SiO2 film is stuck on the aperture edge, side wall and the bottom of the groove 6. A polycrystalline Si layer 9, which is a dielectric material, is filled in the groove 6, and extented to the side etching part 7 in order to make crystal structure compact and make its surface a gentle concavity, and is covered with a SiO2 film 10. Thus, the discontinuations of a wiring to be formed thereon are prevented.
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