Trade-off Characteristic between Gate Length Margin and Hot Carrier Lifetime by Considering ESD on NMOSFETs of Submicron Technology

Abstract

Hot carrier degradation and roll off characteristics of threshold voltage () on NMOSFETs as I/O transistor are studied as a function of Lightly Doped Drain (LDD) structures. Pocket dose and the combination of Phosphorus (P) and Arsenic (As) dose are applied to control roll off down to the gate length margin. It was seen that the relationship between roll off characteristic and substrate current depends on P dopant dose. For the first time, we found that the n-p-n transistor triggering voltage () depends on drain current, and both and snapback holding voltage () depend on the substrate current by characterization with a transmission line pulse generator. Also it was found that the improved lifetime for hot carrier stress could be obtained by controlling the P dose as loosing the roll off margin. This study suggests that the trade-off characteristic between gate length margin and channel hot carrier (CHC) lifetime in NMOSFETs should be determined by considering Electrostatic Discharge (ESD) characteristic.