光刻中驻波效应的影响分析

Analysis of standing wave effect in photolithography

驻波效应是抗蚀剂在曝光过程中的寄生现象。一般认为,驻波效应对薄胶的光刻图形有较大的影响,而对厚胶的光刻图形影响不大。根据DILL曝光模型进行了模拟计算,分析了在曝光过程中抗蚀剂折射率的改变对驻波强度和位置的影响以及驻波效应引起抗蚀剂曝光剂量分布的变化,并结合MACK显影模型分析了当抗蚀剂的厚度改变时,驻波效应对其显影轮廓的影响程度,计算分析得出了一个可以不采用后烘工序的抗蚀剂厚度值。

Standing wave effect in the resist is companied with the exposure process. It is accepted that standing wave does more effect on the lithography patterns of thin resist,whereas less of thick resist. Based on DILL model,we analyze the change of intensity and position of standing wave resulting from the variation of resist refractive index,and the variation of exposure dose induced by standing wave effect in the exposure process. Combined with MACK model,we also analyze its influence extent on the development profile,give a thickness value with which lithography doesn't need PEB procedure.