| 摘要 |
PURPOSE:To enable the improvement of yield without generating warps even with the dielectric-isolating structure of wafers by a method wherein a polycrystalline Si layer serving as the seed is formed thinly on an insulation layer, and this Si layer is single-crystallized by energy beam annealing; thereafter, the bottom surface of a semiconductor substrate is polished. CONSTITUTION:The Si layer serving as the seed, e.g., an Si layer 9 made of polycryatalline Si is grown on an oxide film 5. Next, the process goes into a heat treatment; that is, when the thickness of the polycrystalline Si 9 subjected to e.g. laser annealing is approx. 0.4mum, this Si becomes single-crystallized by an irradiation of 1.2-2.0jJ/cm<2> with Q switch pulse beam lasers 10. A polycrystalline layer 11 of polycrystalline Si is grown on the Si layer 9 thus single-crystallized so as to be approx. 620mum in thickness in total with that of this Si layer. Then, the wafer 1 is lapped to the position 7 shown by a one-dot chain line 7 by polishing from its bottom surface 1a, thereby semiconductor elements and the like are formed in the part having island regions 1b. |
