Forming single crystal silicon on insulator by irradiating a laser beam having dual peak energy distribution onto polysilicon on a dielectric substrate having steps

摘要

A process for the production of semiconductor devices comprising: (1) forming a first oxide film on a semiconductor substrate, (2) forming a groove or grooves on the first oxide film, (3) forming a first polycrystalline silicon film as an active layer on the whole surface of the first oxide film, (4) forming a second oxide film on the first polycrystalline silicon film, (5) forming a second polycrystalline silicon film on the second oxide film, said second polycrystalline silicon film serving as a buffer layer which absorbs the fluctuation of a scanning laser beam irradiating the first polycrystalline silicon film in step (7), (6) forming an anti-reflection film made of an oxide film on said buffer layer, and (7) irradiating the first polycrystalline silicon film with a scanning laser beam having a dual peak type power distribution to melt said first polycrystalline silicon film in such a manner that both peaks in the power distribution of the laser beam are positioned at both outer sides of said grooves, respectively, thereby achieving a single crystallization of said first polycrystalline silicon film serving as an active layer within each of said grooves in which said semiconductor devices are to be formed.