Monte Carlo particle modelling of small semiconductor devices

Abstract

Abstract We have at Reading developed a self consistent Monte Carlo particle model for simulation of semiconductor devices, and proved that it is capable of correctly reproducing laboratory measurements. The method consists of following the detailed transport histories of individual carriers. Physical processes such as interaction between the carriers (holes and electrons) and the lattice (various types of phonon scattering), and the imperfections (impurities). Electron-hole pair creation (i.e. in devices interacting with light) and recombination, avalanche effects, trapping and tunnelling have been included in the model. Although the method was first developed with GaAs MESFETs in mind, it has now been generalised to all cubic semiconductors and to any sort of device. As the model reflects the basic physics of semiconductor devices, it can be used to deepen the physical understanding of such devices. It can also be used as a design tool to evaluate novel ideas. These aspects are discussed. This model is aimed at describing devices of geometrical dimensions of the order of, and smaller than the free flight path of the carriers. As no assumptions have been made regarding diffusion or relaxation of the carriers, like in previous models, this model can be used where non-stationary transport becomes dominant. A review of device simulation carried out by us so far has been given.