SEMICONDUCTOR DEVICE AND METHOD FOR FABRICATING THE SAME

摘要

PURPOSE: A semiconductor device and a fabrication method thereof are provided to improve yield and reliability of the device by forming a lightly doped impurity region with a tilt ion implantation without a gate sidewall. CONSTITUTION: A field oxide layer(32) is grown on an isolation region in a semiconductor substrate(31). A gate oxide layer(33) is formed on the substrate(31) including the field oxide layer(32). A gate electrode(34) is formed on a portion of the gate oxide layer(33) to have a relatively smaller lower part than an upper part. A cap gate nitride layer(35) is formed above the gate electrode(34) to have a relatively smaller lower part than an upper part. A gate bird's beak(36) is formed at a lower edge of the gate electrode(34). Lightly and heavily doped impurity regions(38,40) are formed beneath a surface of the substrate(31) near a side of the gate electrode(34). While the gate electrode(34) and the cap nitride layer(35) formed in a negative sloping profile are used as a mask, a tilt ion implantation is performed to form the lightly doped impurity region(38) without a typical gate sidewall insulator.