Models for electron and hole mobilities in MOS accumulation layers

We present new physically based effective mobility models for both electron s and holes in MOS accumulation layers. These models take into account carr ier-carrier scattering, in addition to surface roughness scattering, phonon and fixed interface charge scattering, and screened Coulomb scattering. Th e newly developed effective mobility models show excellent agreement with e xperimental data over the range 1 x 10(16)-4 x 10(17) cm(-3) for which expe rimental data are available. Local-field dependent mobility models have als o been developed for both electrons and holes, and they have been implement ed in the two-dimensional (2-D) device simulators, PISCES and MINIMOS, thus providing for more accurate prediction of the terminal characteristics in deep submicron CMOS devices. In addition, transition region mobility models have been developed to account for the transition in the mobility in going from the accumulation layer in the gate-to-source overlap region to the in version layer region in the channel.