X射线光刻掩模加工过程中的形变研究

Simulation of X-ray Lithography Mask Distortion in Device Fabrication

对以SiNx 为衬基的X射线光刻掩模在背面刻蚀过程中的形变进行数值仿真 ,研究了Si片和衬基的各种参数对掩模最大平面内形变和非平面形变的影响。结果表明 ,参数的变化明显影响最大非平面形变量。当Si片的厚度和直径增大 ,衬基的厚度和初始应力减小时 ,最大平面内形变与非平面形变减小 ,而衬基的材料对两者的影响不明显。

Numerical simulation of the distortion during back-etching, for the SiNx membrane in X-ray lithography mask, was done. Influences of various factors, including the initial stress, the size of silicon wafer, and the thickness of the Si wafer and the membrane, on both the in-plane distortion (IPD) and out-of-plane distortions (OPD) were studied. The results show that the maximum OPD is most likely affected by variations in factors under consideration. For instance, as the diameter and thickness of silicon wafer increase, and the initial stress and the membrane thickness decrease, both IPD and OPD improve. However, the type of membrane material little affects the two types of distortion.