Hot carrier modeling in metal-oxide-semiconductor devices using the convective scheme

A model for the simulation of the electron energy distribution in nanoscale MOSFET devices, using a kinetic simulation technique, is implemented. The Convective Scheme (CS), a method of characteristics, is an accurate method of solving the Boltzmann Transport Equation, a nonlinear integrodifferential equation, for the distribution of electrons in a MOSFET device. The method is used to find probabilities for use in an iterative scheme which iterates to find collision rates in cells. The CS is also a novel approach to 2D semiconductor device simulation. The CS has been extended to handle boundary conditions in 2D as well as to calculation of polygon overlap for polygons of more than three sides. Electron energy distributions in the channel of a MOSFET are presented. Voltage conditions on the semiconductor device represent high stress (Vg ≃Vd) conditions. As the gate voltage approaches the drain voltage, the worst-case stress condition results in injection of the "high-energy tail" electrons into the oxide. This model is used to compute the electron energy distribution and to explore the importance of Coulomb collisions in the channel of nanoscale MOSFETs. Electron-electron scattering is implemented using a single-particle electron-electron approach in which the scattering frequency depends upon the energy of the incident electron. It is shown that the electron-electron scattering has an influence on the "high-energy tail" and is essential to elucidating the physics of short channel MOSFETs. The CS has low numerical errors so it is an efficient tool to look for subtle effects such as electron-electron collisions. The substrate and gate currents obtained indicate that hot-carrier effects continue to be an issue for device performance, even for nanoscale devices.