Impact of nitrogen implantation in lightly doped drain (NIL) on deep sub-micron CMOS devices

In this study, we investigate the device characteristics of lightly doped d rain (LDD) metal-oxide-semiconductor field effect transistors (MOSFETs) wit h nitrogen implantation in the gate overlapped LDD region. As expected, the hot carrier lifetime under drain avalanche hot carrier (DAHC) stress condi tion is sufficiently improved in nMOSFETs with nitrogen implantation as par t of the LDD (NIL) technique. However, the nitrogen-enhanced short channel effect is observed. The function of nitrogen atoms in pMOS devices has the opposite characteristic, In addition, the effective channel lengths shift i n opposite directions in nMOSFET and pMOSFET. Off-state currents of NIL nMO SFET are degraded, resulting in the deterioration of the short channel leng th margin characteristic, while the short channel length margin is improved in NIL pMOSFET.