X射线光刻掩模背面刻蚀过程中的形变仿真

Simulation of X-ray Lithography Mask Distortion during Back-etching

开发了理论模型以验证有限元方法用于X射线光刻掩模刻蚀过程数值仿真的正确性。利用相同的有限元技术,对X射线光刻掩模的背面开窗、Si片刻蚀过程进行数值仿真。结果表明,图形区域的最大平面内形变(IPD)出现在上、下边缘处,最大非平面形变(OPD)出现在左、右边缘处。此外对Si片单载荷步刻蚀和多载荷步刻蚀的仿真进行比较,结果表明图形区域最终的形变量与Si片刻蚀的过程无关。

An analytical model is developed to verify the numerical simulation for X-ray lithography mask etching process using finite element (FE). The same FE technique was used for the simulation of backside window-opening process and Si wafer back-etching process. The results indicate that the maximum in-plane distortion (IPD) of the pattern area occurred at the top and bottom edge, and the maximum out-of-plane distortion (OPD) occurred at the left and right edge. In addition, the results were compared between the single load step and multi-load steps for Si wafer etching process, which indicate the resulting distortions of pattern area is independent of the Si wafer etching process.