JPS6477119A - Manufacture of semiconductor device - Google Patents

Abstract

PURPOSE:To activate only the surface layer of a semiconductor substrate to form a shallow impurity diffused layer filled up with an amorphous layer by a method wherein a semiconductor substrate is annealed for a short time by irradiating it with energy beams to form the impurity diffused layer. CONSTITUTION:A single crystal silicon substrate 11 is implanted with boron ion to form an amorphous layer 12 in thickness around 0.4mum. Next, the silicon substrate 11 is irradiated with pulse laser beams from the surface to temporarily melt down a part of the amorphous layer 12. Consequently, the amorphous layer 12 is composed of an LG layer 13a comprising single crystal in large grain diameter, an FG layer 13b comprising single crystal in fine grain diameter, a melteddown part 13c and an amorphous layer 13d remaining as a part of the amorphous layer 12 hardened from the surface while the bottom part of the amorphous layer 12 is not yet completely melted down. Finally, when the crystallization is finished, the LG layer 12a, FG layer 13b and the amorphous layer 13d are formed while the single crystal part of the semiconductor substrate 11 is below the amorphous layer 13d. Through these procedures, the LG layer 13a and the FG layer 13b only can be activated to form thin active layers in thickness of 0.1mum.