Boltzmann equation – TechConnect Briefs

Simulation of Gas Flows in Micro Devices by Solving the Boltzmann Kinetic Equation

Anikin Yu.A., Dodulad O.I., Kloss Yu.Yu., Martynov D.V., Tcheremissine F.G., Shuvalov P.V., Moscow Institute of Physics and Technology, National research centre “Kurchatov institute”, RU

Numerical modeling of gas flows in micro devices has practical value due to the high application opportunities of such devices to the relevant industries. Gas behavior is accurately described by the Boltzmann equation of the [...]

Failure of Macroscopic Transport Models in Nanoscale Devices near Equilibrium

Jungemann C., Grasser T., Meinerzhagen B., Technische Universität Braunschweig, DE

The shrinking of the device dimensions below 100nm is pushing the classical TCAD tools like the drift-diffusion (DD) or hydrodynamic (HD) models to their limits. While the impact of the shrinking on the accuracy of [...]

Analytic Formulae for the Impact Ionization Rate for use in Compact Models of Ultra-Short Semiconductor Devices

Morris H.C., DePass M.M., Abebe H., San Jose State University, US

Quade, Schöll and Rudan have showed that in the limit of large screening length the impact ionization rate per unit time can be expressed as an integral involving the electron density function. The assumption of [...]

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

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

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 [...]

An Impact Ionization Model Including an Explicit Cold Carrier Population

Grasser T., Kosina H., Heitzinger C., Selberherr S., TU Vienna, AT

Conventional macroscopic impact ionization models which use the average carrier energy as main parameter cannot accurately describe the phenomenon in modern miniaturized devices. Here we present a new model which is based on an analytic [...]

Non-Parabolicity and Non-Maxwellian Effects on Gate Oxide Tunneling

Gehring A., Grasser T., Selberherr S., TU Vienna, AT

Simulation of gate oxide tunneling currents in subquartermicron devices requires correct modeling of the electron energy distribution function in the channel region. However, the common assumption of a heated Maxwellian distribution function leads to a [...]

The Failure of the Hydrodynamic Transport Model for Simulation of Partially Depleted SOI MOSFETs and its Revision

Gritsch M., Kosina H., Grasser T., Selberherr S., Linton T., Singh S., Yu S., Giles M.D., TU Vienna, AT

An anomalous output characteristics is observed in hydrodynamic simulations of partially depleted SOI MOSFETs. The effect that the drain current reaches a maximum and then decreases is peculiar to the hydrodynamic transport model. It is [...]

Variance Reduction in Monte Carlo Device Simulation by Means of Event Biasing

Kosina H., Nedjalkov M., Selberherr S., Technical University of Vienna, AT

A theoretical analysis of the Monte Carlo (MC) method for the solution of the stationary boundary value problem defined by the Boltzmann equation is briefly outlined. This analysis clearly shows how event biasing can be [...]