Monte Carlo Simulation Of Electron Transport Properties In Ⅲ-Ⅴ Compound Semiconductors

The GaAs, InP-based III-V compound semiconductors, which are known as their wide band-gaps, direct-band transition, high photoelectric conversion efficiency and high saturated electron drift velocity and mobility, become increasingly important and have been widely used in microelectronics and optoelectronics. It is quite valuable to study their transport properties which are the foundation of the applications using these materials.Monte Carlo simulation method is a popular and reliable tool which has been applied to study the carrier transport properties of semiconductor device for many years. It is a statistical probability method which solves physics problems using statistical numerical theory and solves Boltzmann equation directly based on semi-classical transport mode. It's a effective way to simulate the non-local transport properties of semiconductor materials and small size devices.The Monte Carlo method applied to semiconductor carrier transport simulates the movement of the carriers in the semiconductor crystal under the scattering and the external electric field. The carrier's movement depends on the collision and external electric field. The impact of the collision can be estimated by the scattering rate, and the process of carrier under the electric field can be calculated using classical mechanics. This paper presents a systematic theoretical Monte Carlo simulation model and its optimization, including the main scattering mechanisms of carriers, the calculation of electric field and electron charge in devices and the statistical calculation of the primary physical quantities. The transport and current-voltage properties of submicron GaAs MESFET device are calculated firstly based on the nonparabolic effective mass energy band model and Monte Carlo method which includes all major scattering mechanisms. The electron drift velocity, electric field and the non-homogeneity of mobility distribution in device are obtained. The influences of different gate lengths to electron drift velocity and drain current are analyzed. It is shown that the electron drift velocity decreases rapidly and the drain current decreases linearly when increasing gate length. Secondly, the spatial distribution of transport properties of GaP and InP bulks, including electric fields, drift velocities and mobility, are calculated at different applied voltages and an overshoot phenomena in the electron densities and drift velocities of the GaP and InP bulks under the high electric field was found.The results obtained by this paper make further explanations of III-V compound semiconductor transport phenomena, and are helpful for designing semiconductor devices.