| 摘要 |
PURPOSE:To accelerate the oxidization speed in the direction of a substrate thickness, to prevent a bird peak from taking place and to prevent the rediffusion of an inversion preventing layer, by implanting O2 ions preliminerily into the portion where a field oxidized film is to be formed on an Si substrate. CONSTITUTION:An Si3N4 film 13 is formed on an SiO2 film 12 on a P<-> type substrate. Then with a resist-mask 14 coated it is etched so that an Si3N4 mask 13' is formed. By implanting B ions a P<+> inversion layer is formed. Thereafter by implanting 0 ions a layer 16 is formed. After removing the resist mask 14, wet oxidization at a high temperature is performed. The oxidization proceeds from the layer 12 and 16, forming a field oxidized film 17. Then a semiconductor device is formed on the substrate in a region surrounded by the oxidized film 17. With such an arrangement, the oxidized film 17 suppress the oxidization in the lateral direction and grows thickly in a short period of time so that it prevents the bird peak and the rediffusion of the inversion preventing layer, resulting in the improved properties and the greater integration. |
