低能气相腐蚀系统的建模与仿真

Modeling and Simulation of the Low Energy Gas-Phase Etching System

低能气相腐蚀系统在微电子机械系统(MEMS)生产工艺中的应用非常广泛,但是该系统的设计和开发十分复杂。为了降低系统设计的复杂度和生产成本,对低能气相腐蚀系统进行了基于可视化开发工具Lab VIEW的建模和仿真。以Xe F2腐蚀MEMS中的无定形硅为例,对腐蚀速率、时间与腐蚀效果之间的关系进行了研究,重点分析和讨论了建模中需要解决的三个重要问题:循环控制回路中交换腔气体压强的计算方法、恒定腐蚀速率下腐蚀气体压强的计算方法以及非晶硅牺牲材料表面积与时间的关系。根据对反应趋势的计算结果进行仿真,表明在腐蚀一个微结构的过程中,腐蚀速率能够维持恒定。仿真结果验证了该方法可以快速模拟真实的低能气相腐蚀环境,具有准确性和可行性,为后期系统的设计和开发提供了数据参考和技术指导。

Low - energy gas - phase etching systems are widely used in the production process of MEMS, but the design and development of the system are very complex. In order to reduce the complexity of the system design and the production costs, the modeling and simulation of the low - energy gas - phase etching system based on visual development tools Lab VIEW are carries out. With the XeF2 etching amorphous siliconin MEMS as example, the relationship between etching rate, time and etching effect are researched, and three of the essential issues to be resolved in modeling are analyzed emphatically ： the calculation method of the gas pressue in the exchange chamber in the cycling control loop ; the calculation method of the pressure of etching gas under constant etching rate; and the relationship beteen the surface area of the amorphous silicon sacrificial materialand the time. The simulation is conducted in accordance with the calculation results of the reaction trend, in which the constant etching rate can be maintained in the process of etching a microstructure. The simulation results show that the method can emulate the real low - energy gas - phase etching environment quickly,and the simulation method is correct and feasible. It provides reference data and technical guidance for the design and development of the late system.