多晶硅薄膜热应力的在线提取方法

In-Situ Measurement for Thermal Stress of Polysilicon Membrane

提出了一种薄膜热应力的在线提取方法.建立了多晶硅薄膜的热学模型,计算了电流加热后产生的热应力;然后用双端固支梁静电吸合模型计算出吸合电压随热应力的变化,此变化与Coventor Ware软件模拟出的结果一致.在此分析基础上,提出了通过测量加热前后双端固支梁吸合电压的变化值来测其热应力的方法,并给出了测试结构.最后用Coventor Ware软件进行模拟,并经过迭代计算,验证了该测试方法的可行性.该方法测量方便,并且以电学量形式输出,对于多晶硅薄膜热应力的在线提取有较高的参考价值.

A method for in-situ measuring thermal stress of polysilicon membrane was presented. A thermal model of polysilicon membrane was established to calculate the thermal stress generated by the current heating. Based on the electrostatically actuated model of fixed-fixed beam, the change of pull-in voltage with thermal stress was calculated, and the results were in agreement with those simulated by Coventor Ware. On the basis of this analysis, the thermal stress of fixed-fixed beam after heating can be measured by measuring the change of pull-in voltages before and after heating. And the measurement structure was established. Finally Coventor Ware was used to verify this method. The result of iterative computation shows the feasibility of the method, and its output is in the form of electricity. So it is a good reference for in-situ measuring thermal stress of polysilicon membrane.