| 摘要 |
PURPOSE:To increase the performance and integration degree by a method wherein the influence by the impurity diffusion of a field inversion preventing region is eliminated by compensating the area of an element forming region for its reduction, and then the upper surface of a field oxide film and the surface of the element forming region are formed nearly into the same flat. CONSTITUTION:A thermal oxide film 12 is formed by thermally oxidizing a P type Si substrate 11. An Si nitride film 13 is deposited as an oxidation resistant film, and a photo resist pattern 14 is formed. An Si nitride film 13' is formed by selectively etching and removing the Si nitride film 13. Next, boron ion implanted layers 15 are formed. Field oxide films 16 are formed by performing thermal oxidation. The P<+> type field inversion preventing regions 17 are formed thereunder. The substrate 11 is exposed by etching treatment. A P type single crystal Si layer 18 is so deposited on an island form part of the substrate 11 as to be at the same height as the upper surface of the field oxide films 16. |
