Selberherr S. – Page 2 – TechConnect Briefs

A Physics-Based Impact Ionization Model Using Six Moments of the Boltzmann Transport Equation

Grasser T., Kosina H., Gritsch M., Selberherr S., TU Wien, AT

Due to the ever decreasing device geometries non-local effects gain more and more importance. It is particularly well known that impact ionization is not properly described by neither a local field nor a local energy [...]

A Qualitative Study on Global and Local Optimization Techniques for TCAD Analysis Tasks

Binder T., Heitzinger C., Selberherr S., Technical University Wien, AT

We compare the two well-known global optimization methods, simulate annealing and genetic optimization, to a local gradient-based optimization techniques. We rate the applicability of each method in terms of the minimal achievable target value for [...]

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 [...]

Transient Simulation of Ferroelectric Hysteresis

Dragosits K., Hagenbeck R., Selberherr S., Technical University of Vienna, AT

We present amodel that allows the analysis of the behavior of ferroelectric materials in a wide range of frequencies. A common approach to the transient properties of dielectrics based on differential equations was extended by [...]

Inductance Calculation in Interconnect Structures

Harlander C., Sabelka R., Selberherr S., Technical University of Vienna, AT

We present a package based fnite elements for two and three-dimensional analyses of interconnect structures. Two preprocessors allow a layer-based input of the simulation geometry and the specification of the boundary conditions. Additionally, a third [...]

Automatic Device Design Optimization with TCAD Frameworks

Stockinger M., Selberherr S., Technical University of Vienna, AT

A design optimization method is presented which utilizes automatic optimization capabilities within TCAD frameworks. This method is applied to doping profile optimizations of ultra-low-power CMOS transistors with 0.25 and 0.1 um gate lengths. Two different [...]

Closed-Loop MOSFET Doping Profile Optimization for Portable Systems

Stockinger M., Strasser R., Plasun R., Wild A., Selberherr S., TU Vienna, AT

We present a new closed-loop simulation-based optimization process for a 100 nm MOSFET for portable systems such as subscriber units for wireless communications, yielding an almost double drive performance at equivalent stand-by power when compared [...]

A New Analytical Energy Relaxation Time Model for Device Simulation

Palankovski V., Kosina H., Hernandez A., Selberherr S., TU Vienna, AT

We present an empirical model for the electron energy relaxation time. It is based on Monte-Carlo simulation results and is applicable to all relevant diamond and zinc-blende structure semiconductors. The energy relaxation times are expressed [...]

Accurate Three-Dimensional Simulation of Damage Caused by Ion Implantation

Hössinger A., Selberherr S., TU Vienna, AT

We present a Monte-Carlo ion implantation simulation method that allows a very accurate prediction of implantation induced point defects, generation of amorphous areas, and impurity distributions. The implanted impurity profiles can be calculated as well [...]

Numeric Aspects of the Simulation of Two-Dimensional Ferroelectric Hysteresis

Dragosits K., Selberherr S., TU Vienna, AT

Simulation of ferroelectric hysteresis allows the analysis of nonvolatile memory cells which are based on ferroelectric materials. We give an overview of our algorithm for the calculation of effects caused by field rotation. Implementation of [...]