MANUFACTURING METHOD OF SEMICONDUCTOR DEVICE

摘要

A method for manufacturing a semiconductor device is provided to prevent the contamination of an oxide film due to a residual photoresist pattern and to form easily gate dielectrics having different thickness each other by forming a sacrificial nitride film on the gate oxide film of a low voltage region. A device isolation region(12) dividing a first and a second device regions is formed. A first oxide film is formed on the first and second device regions. A sacrificial nitride film is formed on a substrate. The sacrificial nitride film and the first oxide film of the second device region are removed. The second oxide film having a thickness different from the first oxide film is formed on the substrate of the second device region. The sacrificial nitride film is removed. A first gate(14,20) and a second gate(18,20) are formed by selectively etching a polycrystal silicon film and the first and second oxide films. A low density doping region(22) is formed on the substrate. A spacer is formed on the side wall of the first and second gates. A source and drain region(28) is formed by doping an impurity ion with a high density.