METHOD FOR FORMING TRANSISTOR OF SEMICONDUCTOR DEVICE TO IMPROVE CURRENT DRIVING ABILITY

摘要

PURPOSE: A method for forming a transistor of a semiconductor device is provided to improve a current driving ability by forming a gate oxide layer having a native oxide layer and an oxynitride layer on a semiconductor substrate in a cell region. CONSTITUTION: The first gate oxide layer(33) made of an oxynitride layer is formed in a cell region and a peripheral circuit region on a semiconductor substrate(31). Only the cell part of the first gate oxide layer is left by a photolithography process using a mask for forming a dual gate oxide layer. A gate electrode in which the second gate oxide layer(37) and the first gate oxide layer are stacked in the cell region in a subsequent process while a gate electrode including the second gate oxide layer is formed in the peripheral circuit region.