Breakdown Phenomena Of Semiconductor Devices Under The Impact Of Hemp

The reliability of semiconductor devices has become increasingly important in their applications for both civilian and military systems. In some situations, semiconductor devices or circuits must be operated under possible impact of an electromagnetic interference (EMI). In particular, as a high-power EMP is suddenly injected into a transistor, electrical or thermal breakdown can be definitely caused. Normally, there are two methods to investigate the burnout and breakout phenomena of electronic devices under the impact of EMP, one is experiment test, and the other is theoretical research. The theoretical research is very essential because precise test results are difficult to get since the restrictions of complicated semiconductor structures and test environment.We investigate the burnout and breakout phenomena of transistors with theoretical method in this thesis.Firstly, the physical mechanism of device breakout with the impact of EMP is analyzed.Secondly, the semiconductor operation equations for two-dimensional simulation, which are stiff, coupled and nonlinear partial differential, are set up. And the parameters of these equations have been discussed.Then, hybrid time-domain finite element method (FEM) is employed for our mathematical treatment. The heat source generated by the injection of pulse is determined by PISCES-IIB, i.e. a two-dimensional semiconductor device modeling software.Finally, the electrical and thermal characteristics in thin-film transistors and bipolar-junction transistors under the impact of an electromagnetic pulse are simulated by our program.The thesis is mainly about the programming of the two-dimensional semiconductor model simulation. Begun with the basic semiconductor theory,the Maxwell equations and thermal conductivity equation, boundary conditions of the device are analyzed and a two-dimensional model is set up. Then normalization, auto-adjusting grids, discretized equations, and coupled methods are employed to solve the model by TD-FEM (Time Domain-Finite Element Method). Two-dimensional model relates to many equations, complex boundary conditions and a large number of nodes, so a great computing work is necessary.