中文摘要：

在晶圆等离子刻蚀过程中,静电吸盘对调节和控制晶圆表面温度均匀性、保障晶圆加工质量起着重要作用。本文对静电吸盘的传热以及温度控制方法进行了仿真研究。首先对静电吸盘的结构和传热进行分析,将其简化为二维轴对称模型,并验证了模型的可靠性;然后研究了静电吸盘分区PID控制方法,分析了各PID参数对静电吸盘表面温度—时间响应特性的影响;最后引入试验设计方法,结合替代模型方法和遗传优化算法,对PID参数进行整定优化。结果表明,利用该简化的二维模型,可以在误差允许范围内,提高有限元计算的速率;同时本文提出的PID整定方法可有效提高PID参数整定效率,整定结果能够有效改善静电吸盘温度——时间响应特性。

英文摘要：

We addressed via simulation the proportional-integral-derivative（ PID） control of the temperature distribution of the electrostatic chuck in plasma etching of Si wafers,300 ~ 450 mm in diameter. First,the impact of the chuck structure,including the dielectric and heater layers,base and water-cooling channels,on the heat transfer was empirically simplified,mathematically modeled,and numerically simulated with finite element method. The simulated results show that the 2-D symmetric model works pretty well. Next,the influence of the multi-zone PID control variables,such as Kp,Kiand Kd,on the time evolution of the chuck＇s surface temperature in the central,middle and edge heating-zones was simulated. Finally,tuning of the PID controller was performed in design of experiment method combined with surrogate model and genetic optimization algorithm. The results show that the 2-D model greatly simplifies the simulation with allowable uncertainties,and the newly-developed PID tuning technique significantly increases the tuning efficiency and improves the time evolution of the chuck＇s surface temperature.