Semiconductor device and method for fabricating the same

Abstract

A method for fabricating semiconductor device includes the steps of first providing a substrate having a high-voltage (HV) region and a low-voltage (LV) region, forming a first gate structure on the HV region and a second gate structure on the LV region, forming a first lightly doped drain (LDD) adjacent to one side of the first gate structure and a second LDD adjacent to another side of the first gate structure, and then forming a third lightly doped drain (LDD) adjacent to one side of the second gate structure and a fourth LDD adjacent to another side of the second gate structure. Preferably, the first LDD and the second LDD are asymmetrical, the third LDD and the fourth LDD are asymmetrical, and the second LDD and the third LDD are symmetrical.

Dependencies are inferred from the claim text.