Naqvi S S, Gaspar S, Hickman K, Bishop K, McNeil J R
Appl Opt. 1992 Apr 1;31(10):1377-84. doi: 10.1364/AO.31.001377.
A novel laser scatterometer linewidth measurement tool has been developed for critical dimension metrology of photomasks. Calculation of the linewidth is based on a rigorous theoretical model, thus eliminating the need for calibrations. In addition the effect of the glass substrate on which the photomask grating is placed is explicitly taken into account. The experimental arrangement consists of a chrome photomask diffraction grating that is illuminated with a laser. A rigorous theoretical model is used to provide a lookup table that gives the power in the transmitted zero-order beam as a function of the linewidth for a fixed pitch of the grating. The predicted linewidth values are compared with those that are obtained by using commercial optical linewidth measurement systems, and excellent agreement is obtained.
一种用于光掩模关键尺寸计量的新型激光散射仪线宽测量工具已被开发出来。线宽的计算基于一个严格的理论模型，因此无需进行校准。此外，明确考虑了放置光掩模光栅的玻璃基板的影响。实验装置包括一个用激光照射的铬光掩模衍射光栅。使用一个严格的理论模型来提供一个查找表，该查找表给出了对于固定光栅间距，透射零级光束中的功率作为线宽的函数。将预测的线宽值与使用商业光学线宽测量系统获得的值进行比较，结果吻合良好。
