Hs. Kim et al., Device performance improvement based on transient enhanced diffusion suppression in the deep sub-quarter micron scale, JPN J A P 1, 39(4B), 2000, pp. 2172-2176
In the deep sub-quarter micron scale, the transient enhanced diffusion (TED
) of the gate channel region gives rise to the variation of device characte
ristics due to the influence of interstitial silicon atoms generated by the
extension ion implantation damage. The channel impurity variation caused b
y TED becomes a dominant factor and brings about a more severe fluctuation
of the threshold voltage (V-th) than the physical Sate channel length (L-ga
te) or the gate-oxide (G(ox)) thickness variation does. This work presents
the results of suppressing the reverse short channel effect (RSCE) which is
shown due to TED by using the local channel implantation process. In the c
ase of using a boron source as an n-type channel (n-channel) dopant, the 10
% improvement of the RSCE and the 70% reduction of the V-th fluctuation are
achieved through TED suppression by rapid thermal anneal (RTA) treatment.
Furthermore, we not only demonstrates the 15% increase of the current drivi
ng capability but also clearly removes the RSCE by realizing the super-stee
p retrograded (SSR) channel doping profile with an indium species as the n-
channel dopant and adopting RTA process.