半导体异质结器件数值计算的研究

发布时间：2018-08-01 12:48

【摘要】：新型半导体器件随着芯片行业的巨大需求日益层出不穷,其中异质结器件由于其独特的物理特性得到了广泛的应用。如今半导体器件的研究已然离不开仿真软件的帮助,因此研究半导体异质结器件的数值计算具有重要的应用价值。本文主要采用漂移扩散模型作为半导体模拟的基本物理模型。由于异质结构的独特性,本文还建立了异质结界面的电流密度计算模型,这两个模型奠定了异质结器件能够进行数值计算的理论基础。此外,本文还介绍了半导体异质结的基本物理理论,而且还详细介绍了异质结器件模拟中所采用的迁移率模型以及碰撞电离模型。接下来,本文介绍了数值计算中的网格技术、边界条件的处理、求解非线性方程组的收敛判据等,并以Poisson方程的离散为例,重点介绍了数值计算中用于方程离散的数值方法:有限体积法,其主要优点是微分方程离散后依然能保持原方程的守恒性,且物理意义清晰明确、方程形式规范。随后,还介绍了使用牛顿迭代法求解离散后的大型稀疏非线性方程组。而在实际的数值计算中,本论文采用第三方的函数库PETSc替代了这一繁复的工作,所要做的仅仅是设置好函数接口,这使得本论文可以重点关注器件的物理模型,因此大大提高了开发效率。器件的物理模型成功转变为数学模型后,高速发展的现代计算机技术帮助本论文处理复杂的计算问题,从而模拟得到器件的物理特性。本论文基于半导体器件模拟软件SDS,并参考开源软件Genius与商业软件Silvaco,构建了用于异质结器件数值模拟的计算模块,该模块具有耦合性低,可复用性好的优点。接下来,本论文使用SDS软件模拟了三种由不同材料组成的异质结二极管,得到了它们在不同掺杂浓度条件下的物理特性,其中包括平衡态内建电势差、正向以及反向偏压下的电流电压特性曲线等,并通过与Sivalco软件的仿真结果进行对比,检验了SDS软件中异质结器件计算模块的正确性。同时,通过大量的仿真对比优化该模块中的基本参数。最终,本论文依据大量仿真对比的结果,得出结论:本文所开发的半导体异质结计算模块是正确的,能够模拟异质结器件的基本物理特性,并且能得到精确的仿真结果。
[Abstract]:With the increasing demand of semiconductor devices, heterojunction devices have been widely used because of their unique physical properties. Nowadays, the research of semiconductor devices needs the help of simulation software, so the numerical calculation of semiconductor heterojunction devices has important application value. In this paper, drift diffusion model is used as the basic physical model of semiconductor simulation. Due to the uniqueness of the heterostructure, the current density calculation model of the heterojunction interface is established in this paper, which lays the theoretical foundation for the numerical calculation of the heterojunction devices. In addition, the basic physical theory of semiconductor heterojunction is introduced, and the mobility model and collision ionization model used in the simulation of heterojunction devices are also introduced in detail. Then, this paper introduces the grid technique, the boundary condition processing, the convergence criterion for solving the nonlinear equations, and takes the discretization of the Poisson equation as an example. This paper mainly introduces the numerical method for discretization of equations: the finite volume method, whose main advantage is that the differential equation can still maintain the conservation of the original equation after discretization, and the physical meaning is clear and clear, and the formal specification of the equation is also given. Then the Newton iteration method is introduced to solve the discrete large sparse nonlinear equations. In the actual numerical calculation, the third party's function library PETSc is used to replace this complicated work. All we have to do is to set up the function interface, which makes this paper focus on the physical model of the device. Therefore, the development efficiency is greatly improved. After the successful transformation of the physical model of the device into the mathematical model, the rapid development of modern computer technology helps this paper deal with complex computing problems, thus the physical characteristics of the device are simulated. Based on the semiconductor device simulation software SDSs and referring to the open source software Genius and the commercial software Silvaco a numerical simulation module for heterojunction devices is constructed. The module has the advantages of low coupling and good reusability. Then, we use SDS software to simulate three kinds of heterojunction diodes with different materials, and obtain their physical properties under different doping concentrations, including the potential difference built in equilibrium state. The current-voltage characteristic curves under forward and reverse bias voltages are compared with the simulation results of Sivalco software to verify the correctness of the heterojunction device calculation module in SDS software. At the same time, the basic parameters of the module are optimized by a large number of simulations. Finally, based on a large number of simulation results, this paper draws the conclusion that the semiconductor heterojunction calculation module developed in this paper is correct, can simulate the basic physical characteristics of heterojunction devices, and can obtain accurate simulation results.
【学位授予单位】：电子科技大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN303

【相似文献】