METHOD FOR PRODUCING MOSFET

摘要

PURPOSE: A method for producing a MOSFET(Metal Oxide Semiconductor Field Effect Transistor) is provided to simplify a producing process by proceeding a following process with performing an LDD(lightly doped drain) ion implantation after forming a gate electrode, and to improve the reliability of a processing yield rate and an element operation by improving a characteristic of a deviation with a diffusion into an LDD channel. CONSTITUTION: A production method of MOSFET comprises processes of: forming a gate insulating film on a semiconductor substrate(10); forming a gate electrode having a larger width than a designed critical size with a pattern of conductive layer to be able to thermally oxidize on the gate insulating film; performing an LDD ion implantation on the semiconductor substrate in both sides of the gate electrode; thermally oxidizing the exposed semiconductor substrate and the gate electrode, but forming a thicker thermally oxidized film than a substrate surface in a side wall of the gate electrode by a speed difference of thermal oxidation between the substrate and the conductive layer; and forming a source/drain region on the semiconductor substrate in both sides of the thermally oxidized film. The produced MOSFET is formed the oxidized film of gate(12) and the gate electrode(14) formed by a polycrystalline silicon on the P-typed semiconductor substrate of silicon wafer, the thermally oxidized film(24) formed by thermally oxidizing the gate electrode(10) is formed in the side wall of the gate electrode(14), and the LDD and the source/drain region(18)(22) are formed on the semiconductor substrate(10) in both sides of the gate electrode(10).