反向开关复合管的物理模型与数值方法实现

Physical Model and Numerical Algorithm Realization for RSD

从大注入半导体物理的基本理论推导得到了反向开关复合管(RSD)工作的基本物理方程.通过考虑大注入和强电场效应,建立了RSD以pnn+二极管方式工作于反向预充阶段,以pin二极管方式工作于正向导通阶段的物理模型.采用有限差分法把器件工作的偏微分方程转化为差分方程,并将相应的边界条件转化为精度较高的离散化形式.结合RSD工作的典型电路建立电路方程组,采用Runge-Kutta方法求解,由非平衡载流子分布得到了RSD的电压、电流波形.通过RSD的放电实验与模型计算进行比较,分析了误差产生的原因,论证了物理模型本身及数值方法的合理性.通过应用电路说明了模型及算法的实用价值.物理模型和数值方法对于RSD器件设计及仿真电路的开发具有指导意义.

Fundamental equations for an RSD are derived through semiconductor theory. By considering the high level injec-tion and high electric field effects,a physical model of an RSD is constructed,in which the reverse injection process is under pnn＋ diode operation and the forward conduction process is under pin diode operation. Through the limit difference method, the partial differential equation of the semiconductor device is transformed into a difference equation, and the corresponding boundary condition is discretized with high accuracy. Combined with a typical RSD circuit,the circuit equations are written, and the voltage-time and current-time waveforms are gotten by means of the Runge-Kutta algorithm and the non-equilibrium carrier distribution. By comparing an RSD discharge experiment and model computation, the difference between the theoreti-cal results and the experimental results are analyzed. The practical value of the model and algorithm is shown through an ap-plication circuit. As a result,the physical model and the numerical algorithm are proved valid, which lead a predictive role for RSD device design and circuit simulation.