不同杂散光模型对光刻掩膜特征尺寸影响研究

Different Ration of Flare on Critical Dimensions Based on Improved Stray Light Simulation Model

杂散光仿真模型在光刻投影系统应用中具有重要的作用。由于杂散光对光刻掩模特征尺寸CD(Critical Dimension)成像有一定的影响,亟需一种恰当的杂散光成像模型。通过采用PSF_F函数杂散光拟合模型和Kirk杂散光模拟模型,提出了一种改进的考虑杂散光成像的光刻模型。利用改进的杂散光模型研究了在相同杂散光总量下,不同比例中程、远程杂散光对特征尺寸的影响。结果显示,当总杂散光量相同时,仿真分析得出远程杂散光的影响大于中程杂散光,即远程杂散光的比例占的越大,显影后的特征尺寸比实际特征尺寸越小。

The model of analyzing stray light is very important in optical lithography. Because the CD (Critical Dimension) variation is influenced by stray light. In that case, it is needed an appropriate model for description of imaging with stray light. By using PSF F function model and Kirk flare model, an improved lithography imaging model is proposed. The effect of flare on CD is studied, which the total flare is the same but different ratio of local range and long rang flare. The simulation results show that the long range flare has bigger impact on CD than local range flare, and the bigger its ratio the smaller line-width of CD.