TRANSISTOR MANUFACTURING METHOD USING ARC-MODE SIDEWALL SPACER

PURPOSE: To eliminate the factors of a junction leakage at a source-drain region by forming the outer side face of a sidewall spacer in arc mode, such that the angle between the outer side face of the sidewall spacer and a silicon substrate is 90 deg. or less. CONSTITUTION: A polysilicon sidewall spacer 25 is oxidized for a specified time in a terminal oxidation process to form a oxidized polysilicon sidewall spacer 26. The oxidized polysilicon sidewall spacer 26 is then removed by an anisotropic or isotropic etching, e.g. wet etching or dry etching, where the etching selection ratio between oxide and polysilicon is high thus forming an arc made sidewall spacer 25A. Since the angle between the spacer and a lower layer becomes 90 deg. or less, silicon defects due to As ions indispensably employed in an N-type MOSFET process is eliminated, and leakage current is suppressed resulting in a stabilized operation.