METHOD FOR FABRICATING GATE OF SEMICONDUCTOR DEVICE

摘要

PURPOSE: A method for fabricating a gate of a semiconductor device is provided to prevent an undercut from being formed in the lower portion of a damascene groove when a silicon layer for a dummy gate and a silicon oxide layer are wet-etched, by patterning the silicon layer for the dummy gate and by performing a thermal oxide process. CONSTITUTION: An insulation layer for the dummy gate is formed on a semiconductor substrate(20) having a field oxide layer. The silicon layer for the dummy gate and a hard mask layer are sequentially deposited on the insulation layer. The hard mask layer is transformed to a mask pattern. The silicon layer for the dummy gate is patterned by using the mask pattern as an etch barrier. A thermal oxide process is performed regarding the resultant structure to form a thermal oxide layer(24) on both sidewalls of the silicon layer for the dummy gate. A spacer(25) is formed on both sidewalls of the silicon layer for the dummy gate. An interlayer dielectric(26) is deposited on the resultant structure. The interlayer dielectric is polished to expose the silicon layer for the dummy gate. The silicon layer for the dummy gate and the insulation layer for the dummy gate are removed to form a damascene structure by using the interlayer dielectric as an etch barrier. A gate insulation layer and a metal layer for a gate are deposited. The metal layer for the gate and the gate insulation layer are polished until the interlayer dielectric is exposed.