| 摘要 |
PURPOSE:To enhance accuracy, and to enable to form a unit transistor in a fine type at a semiconductor device by a method wherein a polysilicon layer for formation of a main electrode, an oxide film having the prescribed thickness and an electrode region are provided. CONSTITUTION:A poly-silicon layer 33 is formed on an epitaxial layer 32, and the poly-silicon layer 33 is patterned using a resist layer 34 as a mask. After the resist layer 34 is peeled off, by forming an oxide film 36 according to an oxidation treatment under the normal oxidation condition of silicon, the lateral direction (the circumference) of the poly-silicon layer 33 is also oxidized nearly uniformly, and an oxide film 36 having the prescribed thickness is formed. After a nitride film 35 is removed, by performing thermal diffusion or ion implantation of P type impurities of boron, etc., to the epitaxial layer 32, a gate region 37 having the outside circumferential edge to be lined up with the outside circumferential edge of the oxide film 36 is formed. After a nitride film 39 is removed, N type imprities of P, As, etc., are doped to the poly-silicon layer to make the poly-silicon layer thereof to function as a source electrode 33'. |
