| 摘要 |
PURPOSE:To sufficiently reduce the resistance of the source and drain regions even in the case of reducing the film thickness of an active layer, by a method wherein a gate oxide film and an active layer having a smaller film thickness than a semiconductor film are formed by thermally oxidizing a required section of the semiconductor film. CONSTITUTION:A polycrystalline Si film 2, an SiO2 film 11, and an Si3N4 film 12 are formed on a quartz substrate 1, and a polycrystalline Si film 2b is exposed by etching and thermally oxidized, resulting in the contruction of the gate oxide film and the active layer. Then, an SiO2 film 3 and a polycrystallin Si film 2c are formed. A DOPOS film 13a is formed by adhesion and etching of a DOPOS film 13, and the films 12 and 11 are removed. A PSG film 14 is adhered, and the source region 6 and the drain region 7 are formed by diffusing phosphorus into the film 2 on heating to hight temperatures. Then, the active layer can be constructed extremely thin, and the resistance of the source region 6 and the drain region 7 can be reduced can be reduced because of large film thicknesses of polycrystalline Si films 2d and 2e. |
