Semi-Analytic Boltzmann Model for the Substrate Current of Short-Channel MOSFETs with Lightly Doped Drains

H.C. Morris, M.M. De Pass
San Jose State University, US

Keywords: boltzmann equation, lightly doped drain, impact ionization, substrate current

Abstract:
As MOSFET sizes have been reduced to nano-scale dimensions, existing models of device behavior, such as the drift diffusion equations, cease to be valid. In the nano domain, more fundamental equations, such as the Boltzmann equation and its quantum analogs, must be utilized. This paper presents a new technique for obtaining practical formulae for the impact ionization (I.I.) generation rate Gii in ultra-short-channel Lightly Doped Drain (LDD) MOSFETs. We present relevant new formulae for the substrate current Isub that can be compared with empirical data and utilized in SPICE-type simulations.

NSTI Nanotech 2003 Conference Technical Program Abstract