Method of manufacturing semiconductor device by two stage heating of deposited noncrystalline semiconductor

Abstract

A polycrystalline or polysilicon film having large grain size, such as 1 &mgr;m to 2 &mgr;m in diameter or greater, is obtained over the methods of the prior art by initially forming a silicon film, which may be comprised of amorphous silicon or micro-crystalline silicon or contains micro-crystal regions in the amorphous phase, at a low temperature via a chemical vapor deposition (CVD) method, such as by plasma chemical vapor deposition (PCVD) with silane gas diluted with, for example, hydrogen, argon or helium at a temperature, for example, in the range of room temperature to 600° C. This is followed by solid phase recrystallization of the film to form a polycrystalline film which is conducted at a relatively low temperature in the range of about 550° C. to 650° C. in an inert atmosphere, e.g., N or Ar, for a period of about several hours to 40 or more hours wherein the temperature is gradually increased, e.g., at a temperature rise rate below 20° C./min, preferably about 5° C./min, to a prescribed recrystallization temperature within the range about 550° C. to 650° C. Further, between the step of film formation and the step of solid phase recrystallization, the film may be thermally treated at a relatively low temperature, e.g., over 300° C. and preferably between approximately 400° C. to 500° C. for a period of several minutes, such as 30 minutes, to remove hydrogen from the film prior to solid phase recrystallization.