| 摘要 |
PURPOSE:To improve the withstanding voltage of an oxide film by previously implanting iron ions to the surface of a semiconductor substrate and introducing said iron to said oxide film while an insulating film is formed on the surface of said substrate through thermal oxidation. CONSTITUTION:The ions of iron (Fe) are implanted to the surface of a silicon substrate 1 under the conditions of acceleration voltage of 30keV and the quantity of a dose of 1X10<11> atoms/cm<3>, and the distribution of ion implantation having peak concentration of 4X10<16> atoms/cm<3> is obtained at the position of 25nm under the surface of the substrate 1. Said substrate 1 is thermally oxidized for twenty min in a dried oxygen atmosphere at 1,000 deg.C to acquire a silicon oxide film 2 in 40nm thickness. The distribution curve 3 of iron concentration in the substrate and the silicon oxide film 2 is obtained at that time. An Al-Si electrode is formed on the upper surface of the substrate 1, and an ohmic contact surface is shaped on the lower surface of said substrate 1, thus manufacturing a semiconductor device. Accordingly, the SiO2 film 2 having excellent isolation voltage can be formed beccause the ions of a fixed quantity of Fe are implanted previously to the surface of the silicon substrate 1 and the substrate is thermally treated. |
