T. Furukawa et al., RECOVERY OF TIME-DEPENDENT DIELECTRIC-BREAKDOWN LIFETIME OF THIN OXIDE-FILMS BY THERMAL ANNEALING, Journal of applied physics, 82(7), 1997, pp. 3462-3468
Electrical properties of thin silicon dioxide films have been investig
ated for samples that suffered from the Fowler-Nordheim (F-N) stress a
nd subsequent annealing. The time-dependent dielectric breakdown (TDDB
) lifetime for samples after annealing > 400 degrees C was found to be
longer than that without anneal; about 60% of the amount of damage re
sponsible for the lifetime was annealed out at a temperature of typica
lly 800 degrees C for 30 min. On the other hand, capacitance-voltage (
C-V) measurements indicated that trapped charges were almost annealed
out even at a temperature of 300 degrees C for 30 min. Moreover, the r
einjection of F-N current showed that the trapping sites of holes and
electrons which are electrically neutral remained after the annealing
of trapped charges at temperatures > 300 degrees C. It follows that th
e recovery of TDDB lifetime presently observed through annealing at te
mperatures >400 degrees C was caused by the anneal of neutral trapping
sites created by F-N stresses. (C) 1997 American Institute of Physics
.