| 摘要 |
PURPOSE:To give no bad influence to characteristics of a device existing in a low layer by doing ion implantation of a same semiconductor element into a boundary surface between a semiconductor film and a semiconductor single crystal layer in a seed portion and the whole of the semiconductor film for making an amorphous and then by annealing them to reduce energy required for annealing. CONSTITUTION:On an Si single crystal substrate 1 is formed an SiO2 film 2, on which a polycrystalline Si film 3 is built up and the whole of the polycrystal line Si film 3 and boundary region between the polycrystal line Si film and the single crystal substrate 1 are made to be an amorphous by implanting multiple ions of Si into them. Next, an Si thin film 4 made to be an amorphous is heated and fused to hasten recrystallization. Because a region including a seed crystal is made to be an amorphous, the region is provided with a lower fusion point than that of the Si polycrystal, thereby to allow a laser power to be reduced. Furthermore, since an absorption coefficient of the amorphous Si is larger by one digit than that of the polycrystal Si at the wavelength of the laser, the amorphous Si can be effectively heated. An amorphous Si thin film contacted with the Si single crystal substrate 1 just after fusion starts recrystallization selectively and epitaxially because of large thermal conductivity, and moreover, hastens recrystallization to an amorphous Si film on the SiO2. |
