PURPOSE: To improve the characteristics of a transistor to a large extent, by depositing a silicon dioxide film on a silicon thin film from the outside, thereafter performing thermal oxidation, thereby making the thickness of the silicon thin film further thin.
CONSTITUTION: A silicon thin film 302 is deposited on an n insulating substrate 301. The film thickness is made to be, e.g. t0=500. Then, a silicon dioxide film 303 is deposited on the entire surface. The film thickness is made to be, e.g. toxo=1,300. In this case, the silicon dioxide film can be formed by any method if the film is not formed by oxidizing the silicon thin film but is directly depsited from the outside. Thermal oxidation treatment is performed, and a film thickness 304 of the silicon dioxide film on the silicon thin fil is grown. The final film thickness of the silicon thin film becomes t1=400 by the thermal oxidation. After a gate electrode 305 has been formed, impurities are introduced into the silicon thin film, and a source region 306 and a drain region 307 are formed. Then, an interlayer insulating film 308 is deposited, contact holes are provided, and a source electrode 309 and a drain electrode 310 are formed.
KODAIRA TOSHIMOTO
MANO TOSHIHIKO
