Parameter Modeling for Higher-Order Transport Models in UTB SOI MOSFETs

The accurate description of carrier transport in emerging devices based on Boltzmann’s equation (BTE) is of fundamental importance. The BTE is conventionally solved by applying the Monte-Carlo (MC) technique, which is very accurate but time consuming [1, 2]. A more efficient way to find approximate solutions is the method of moments. For an accurate description of carrier transport it is important to model several transport parameters, like the carrier mobility in the drift-diffusion model, with as few simplifying assumptions as possible. A good choice is the calculation of parameter tables extracted from MC simulations for a parameter interpolation within a device simulator [3]. So far only bulk MC data has been taken into account. The application of this data to MOSFET devices is problematic due to the importance of surface scattering and quantization in the channel [4]. In [5] the influence of surface roughness scattering on the carrier mobility has been considered using the semiempirical Matthiesen rule. However, the impact of quantization effects and surface roughness scattering on higher-order parameters like the energy relaxation time or the energy mobility has not been described satisfactorily yet. We extract this data from a subband MC (SMC) simulator selfconsistently to a Schrödinger Poisson solver [6] where quantization effects and surface roughness scattering are automatically considered.