METHOD FOR MANUFACTURING SEMICONDUCTOR DEVICE

PURPOSE: A method for manufacturing a semiconductor device is provided to improve a threshold voltage, short channel effect and ESD(ElectroStatic Discharge) by forming an air-tunnel at lower part of a channel. CONSTITUTION: An SiGe film and the first polysilicon layer(15) are sequentially formed on a substrate(11). A contact hole is formed by selectively etching the first polysilicon layer. An air-tunnel(17) is formed by wet-etching of the exposed SiGe film. The second polysilicon layer(19) is filled into the contact hole. A gate insulating pattern(21), a gate electrode(23) and a mask insulating pattern(25) are sequentially stacked on the resultant structure. After forming an LDD(Lightly Doped Drain) region(27), an insulating spacer(29) is formed at both sidewalls of the stacked structure. Then, a source/drain region(31) is formed in the substrate.