MANUFACTURE OF FIELD EFFECT TRANSISTOR

PURPOSE:To form the title field effect transistor in extremely fine gate length shorter than the limit size of pattern rule using a dummy gate. CONSTITUTION:Before the formation of a dummy gate, an aluminum film 5a as the first mask layer and a resist layer 6 as the second mask layer are laminated and after the selective exposure of a resist layer 6, the aluminum film 5a is patterned while being side-etched using the resist layer 6 as a mask. At this time, the aluminum film 5a is undercut by the side-etching step thereby enabling a residual dummy gate in extremely fine size to be formed.