| 摘要 |
PURPOSE:To stabilize an ion implantation without using a resist film by employing the difference of oxidation speed in low temperature oxidation of high impurity density polysilicon and substrate and forming a mask oxidized film by the oxidation thereof on the gate electrode of polysilicon. CONSTITUTION:A P-well region 21, a buried field oxidized film 22 and a gate oxidized film 23 are formed on an Si substrate 20, and an N type doped polysilicon gate electrode 24 is formed on the film. The entire substrate is oxidized at a low temperature, thereby forming a mask oxidized film 24. P type source and drain regions 26, 27 of P channel IGFFET are formed on the substrate 20. The source and drain regions 30, 31 of an N channel IGFET are formed on the region 21. In this manner, an ion implantation is stabilized without using a photoresist film as a mask for ion implantation. |
