Transport Property Of Electrons In GaN Heterojunction

Group III nitride semiconductor materials have received much attention, and become a research hot spot in recent years. GaN-based high electron mobility transistors (HEMT) have broad potential application prospects. The main contents of this thesis is to investigate the sub-band energy levels, the density, the distribution, and the mobility of two dimensional electron gas (2DEG) in group III nitride heterojunctions, which is from basic structure of GaN-HEMTs.First of all, by solving the Poisson equation and Schrodinger equation self-consistently, we obtain the sub-band energy levels and electron distribution of2DEG. Schottky barrier height was using to determine the Fermi energy level, which is a new method for that.In the following chapter, several important scattering mechanisms, such as interface roughness scattering, alloy disorder scattering, polar optical phonon scattering are introduced. The dependence of defect scattering rate to temperature was studied by taking the dependence of the electron thermal kinetic energy on temperature into account.Finally, two new scattering mechanisms, surface roughness scattering and interfacial misfit dislocation scattering, are presented with detailed description and calculation. Results show that they play significant roles to scatter the electron. The used method of treatment can be applied not only to GaN heterojunction but also to other type heterojunction systems.Work of this thesis is a good guidance for application.