  A 2D quantum ballistic transport model based on the non-equilibrium Green's
function formalism has been used to theoretically investigate the effects
induced by an oxide crenel in a very short (7 nm) thin-film
metal-oxide-semiconductor-field-effect-transistor. Our investigation shows that
a well adjusted crenel permits an improvement of on-off current ratio Ion/Ioff
of about 244% with no detrimental change in the drive current Ion. This
remarkable result is explained by a nontrivial influence of crenel on
conduction band-structure in thin-film. Therefore a well optimized crenel seems
to be a good solution to have a much better control of short channel effects in
transistor where the transport has a strong quantum behavior.
