| 摘要 |
PURPOSE:To obtain a polycrystalline thin film having large crystal grains by forming on a predetermined substrate a semiconductor thin film to be divided into crystal grains by heat treatment, heat-treating the thin film, then superposing thereon a second semiconductor thin film, implanting a predetermined ion, and performing heat treatment. CONSTITUTION:A polycrystalline Si thin film 3 of a predetermined shape is formed on the SiO2 film on a quartz substrate 1, annealed in N2 at 1,000 deg.C thereby to be divided into a large number of crystal grins 8. This structure is covered with a resist 9 and lapped to planarize the surface of the crystal grains, thereafter the resist is removed and a polycrystalline film 10 is superposed thereon. Then, Si<+> is implanted to change the film 10 into an amorphous Si layer 11 except the lowermost portion thereof. When annealing is performed at 600 deg.C, the crystal grains 8 become a seed and a polycrystalline Si film 7 recrystrallizes. The size of the crystal grains of this polycrystalline Si thin film is larger than the conventional ones, and with this thin film, a thin film semiconductor device having a good characteristic can be obtained. |
