Ds. Ang et Ch. Ling, A NEW ASSESSMENT OF THE SELF-LIMITING HOT-CARRIER DEGRADATION IN LDD NMOSFETS BY CHARGE-PUMPING MEASUREMENT, IEEE electron device letters, 18(6), 1997, pp. 299-301
By progressively lowering the gate-base level in the charge pumping (C
P) measurement, the channel accumulation layer is caused to advance in
to the LDD gate-drain overlap and spacer-oxide regions, extending the
interface that can be probed. This constitutes the basis of a new tech
nique that separates the hot-carrier-induced interface states in the r
espective regions. Linear drain current degradation, measured at low a
nd high gate bias, provides clear evidence that interface state genera
tion initiates in the spacer region and progresses rapidly into the ov
er-lap/channel regions with stress time in a two-stage mechanism, invo
lving first a series resistance increase and saturation, followed by a
carrier mobility reduction.