| 摘要 |
PURPOSE:To form the gentle surface and acquire high quality wiring by respectively forming a narrow inter-element isolation region which the buried structure and a wide inter-element isolation region by the selective oxidation method. CONSTITUTION:A narrow inter-element isolating region 15, wherein an SiO2 14 is buried through a thermal oxide film 13 in the inter-element isolation groove 12 formed on an Si substrate 11, is formed in the memory cell region of the substrate 11 where active elements are mainly arranged in a high density. Moreover, a wide inter-element isolation region 17 consisting of selective oxidation film 16 is formed in the peripheral circuit forming region of the substrate 11. In addition, a cell transistor Tr1 is formed on the substrate surface defined and isolated by the region 15, while the peripheral transistor Tr2 is formed on the substrate surface defined and isolated by the region 17 and on the substrate surface defined and isolated by the regions 15 and 17, respectively. When a semiconductor IC is thus formed, the surface becomes gentle and high quality wiring can be acquired. |
