Semi-analytic Modeling for Hot Carriers in Electron Devices

The paradigm shift from a field- to an energy-based framework in the modeling of hot-carrier-induced degradation has triggered a detailed microscopic view on the degradation mechanisms in MOSFET devices (see also chapter “The Spherical Harmonics Expansion Method for Assessing Hot Carrier Degradation”). The knowledge of the carrier energy distribution inside the device is the main ingredient enabling the energy-dependent approaches. However, efficient and reliable hot-carrier modeling in electron devices is a challenging task. This chapter presents a novel semi-analytical approach to model hot-carrier transport in MOSFET devices. The new approach is inherently non-local and: (a) considers full-band aspects of the silicon band structure, (b) includes major inelastic scattering mechanisms such as optical phonons, impact ionization and carrier-carrier scattering. The model is extensively compared against reference full-band Monte Carlo simulations in terms of distribution functions as well as bulk and gate currents over a wide range of gate lengths and bias conditions. The obtained good agreement confirms the accuracy of the adopted approach that offers an efficient alternative to Monte Carlo and Spherical Harmonics Expansion for hot-carrier modeling.