建立了光刻工艺中内应力的三维有限元分析模型，采用热-结构耦合分析，研究了胶膜厚度、后烘温度以及降温速率对SU-8胶层中的内应力产生的影响。综合以上因素发现，较胶膜厚度和后烘温度，降温速率对胶膜应力影响最大，降温速率越小，胶膜内应力越小，当降温速率小于6 ℃/h时，进一步降低降温速率对内应力影响不大。根据上述仿真结果进行了全金属光栅的工艺实验，发现与内应力相关的问题得到了有效解决。

A three-dimensional finite element analysis (FEA) model is constructed and the influences of some parameters such as the film thickness, post-exposure-bake (PEB) temperature, cooling rate on the stress are numerically investigated employing thermal-structural coupling analysis based on the model. The simulation results shows that cooling rate has much more influence on the stress than the film thickness and PEB temperature and the stress is inversely proportional to the cooling rate. And the stress drops slightly when the cooling rate is lower than 6 ℃/h. The optimization experiment is carried out according to the simulation results and the phenomenon concerning the stress disappears, which proves the validity of the simulation method and results.