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 drain (LDD) metal-oxide-semiconductor field effect transistors (MOSFETs) with nitrogen implantation in the gate overlapped LDD region. As expected, the hot carrier lifetime under drain avalanche hot carrier (DAHC) stress condition is sufficiently improved in nMOSFETs with nitrogen implantation as part of the LDD (NIL) technique. However, the nitrogen-enhanced short channel effect is observed. The function of nitrogen atoms in pMOS devices has theopposite characteristic. In addition, the effective channel lengths shift in opposite directions in nMOSFET and pMOSFET. Off-state currents of NIL nMOSFET are degraded, resulting in the deterioration of the short channel length margin characteristic, while the short channel length margin is improved in NIL pMOSFET.