Naval Research Laboratory, Washington. Monte Carlo simulations are made to examine the basic failure mechanisms in semiconductor devices. This Monte Carlo particle model is a completely physical method of solving Boltzmann's transport equation and Poisson's field equation self-consistently in both time and space. There are no fitting parameters. The method is based on first principles of physics in that the transport histories of individual particles are followed in detail.
Transport consists of free flights of electrons and holes interrupted by scattering.
The duration of the flights and the occurrence of scattering are distributed statistically. Computer simulation is carried out by selecting random numbers of the same distributions. Potential profiles and location of carriers at time intervals as short as 5 fs allows excellent insight into the physics of the device under study. Failure mechanisms resulting from accelerated RF life testing of HEMTs were simulated. In the failed HEMTs it was also found that the peak transconductance was reduced and shifted to lower gate bias.