METHOD FOR FORMING GATE OXIDE LAYER OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for forming a gate oxide layer of a semiconductor device is provided to be capable of reproductively forming an ultra-thin film as the gate oxide layer by using a conventional furnace. CONSTITUTION: An isolation layer(22) is formed at a silicon wafer(21) for defining an isolation region and an active region. At this time, the active region is divided into a thick film region and thin film region. The first gate oxide layer(23a) containing nitrogen is formed at the thick and thin film region of the silicon wafer. Then, the first gate oxide layer of the thin film region is etched for selectively exposing the silicon wafer. The second gate oxide layer(26) is formed at the thin film region by carrying out a thermal oxidation in a conventional furnace under oxygen gas atmosphere. At this time, the second gate oxide layer is thinner than the first gate oxide layer.