| 摘要 |
PURPOSE:To obtain an MOS semiconductor device which has preferable device charateristics by uniformly or decreasingly forming the crystal defect density of a semiconductor layer formed on an insulator in thicknesswise direction, thereby reducing the drain leakage current and reducing the depth of the diffusing length of source and drain regions. CONSTITUTION:A silicon film 2 is epitaxially grown by thermal decomposition of silane SiH4 on a sapphire substrate 1, silicon ions are implanted in the boundary of the silicon and the sapphire, thereby forming the boundary in amorphous state. The region having preferable crystallinity of the silicon surface is converted to single crystal as seeds of solid phase epitaxial growth, thereby improving the crystallinity of the silicon and sapphire boundary region. Then, silicon ions are implanted in the surface of the silicon film, are converted to amorphous state, and are heat treated, thereby growing solid epitaxially from the region of the boundary between the silicon and the sapphire. |
