| 摘要 |
PURPOSE:To widen the scope of selection of a power of laser beams employed for turning polysilicon to be of single crystal, by laser-annealing the part of an epitaxial layer which is located in the vicinity of a region in which an island is formed, and by laser-annealing the epitaxial layer in said region sequentially. CONSTITUTION:An insulation layer 12 of SiO2 is formed at intervals on a silicon substrate 11. Then, silicon is made to grow on the whole surface to form an epitaxial layer 13. On the occasion, a polysilicon layer 13b is formed on the insulation layer 12 made of SiO2, while a single-crystal layer 13a grows on the part in which the substrate is exposed. Next, laser annealing is started from a boundary portion, and a laser beam 14 is shifted toward the polysilicon layer 13b. Then polysilicon melted by the beam is turned to be of single crystal with single-crystal silicon working as a seed. Since the polysilicon layer 13b is located on the insulation layer 12 of SiO2 of small thermal conductivity, it is melted completely by a laser beam of low power. |
