| 摘要 |
PROBLEM TO BE SOLVED: To obtain a high-quality polycrystal semiconductor layer, by etching the surface layer of a polycrystal semiconductor layer obtained by projecting an energy beam on a semiconductor layer having a thickness not larger than a predetermined value, and by exposing to the outside the etched new crystal surface, and further, by forming a next semiconductor layer thereon to polycrystallize it. SOLUTION: In the manufacturing method of a semiconductor device, after depositing an SiO2 film 2 on the surface of a glass substrate 1 by a chemical vapor phase deposition, etc., an amorphous Si film 3 is formed on the SiO2 film 2 by a plasma CVD. Then, after projecting an excimer laser beam on the surface of the amorphous Si layer 3 at a room temperature in a nitrogen atmosphere, the amorphous Si layer 3 is melted and cooled to change it into a polycrystal Si layer 3a. Subsequently, after processing in an aqueous solution of hydrofluoric acid the substrate 1 having the polycrystal Si layer 3a, its surface is changed into a non-amorphous Si layer 3b by an ion doping. Then, after etching the non-amorphous Si layer 3b by a hydrogen plasma, a non-amorphous Si layer 5 is deposited on the polycrystal Si layer 3a. Next, after subjecting the substrate 1 to a heat treatment, an excimer laser beam 6 is projected thereon to convert the non-amorphous Si layer 5 into a polycrystal Si layer 5a.
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