METHOD FOR FABRICATING ASYMMETRICAL LDD MOS DEVICES

摘要

A method of fabricating a true-LDD MOS transistor is described. The fabrication method includes the step of forming an LDD photoresist mask layer on a semiconductor substrate. The mask is aligned to the gate structure and extended to cover a drain region, a lightly doped ion implant is performed in the drain region which is self-aligned with the gate structure and the LDD photoresist mask is removed. Spacers are then formed on the source side and the drain side of the gate structure and a heavily doped ion implant is applied to dope the source region and the drain region which are self-aligned with the gate structure and spacers.