高保真度五步加载纳米压印光刻的研究

Five-Step Loading Locus for High-Conformity Patterning in Nanoimprint Lithography

从理论上建立了压印光刻工艺中留膜厚度与压印力的关系,为压印预设曲线的建立提供了理论依据.基于液态光敏抗蚀剂在紫外光照射下发生光固化反应这一特性,对固化过程进行了详细的分析,建立了抗蚀剂的固化深度与紫外光曝光量之间的关系.在分析了现有压印工艺存在的问题后,提出了一个全新的压印工艺:高保真度固化压印,即包括特征转移-抗蚀剂减薄-脱模回弹力释放-保压光固化-脱模等压印过程.实验结果表明,高保真度固化压印过程与加载路线能实现复杂图形特征的复制,从而保证了压印图形的保真度,并可保证图形复制的一致性及适度留膜厚度,压印图形的分辨率可达100 nm.

In the nanoimprint lithography process, a mathematical equation is formulated to demonstrate the relationship of the residual resist thickness and the pressing force during pressing the template toward the resist-coated wafer. Associated with ultraviolet-curing characteristics of the liquid polymer resist, the relationship between the curing depth of resist and ultraviolet exposure is also established. Based on these analytical investigations, a five-step loading locus, which includes a pre-cure release of the pressing force, is proposed for the high-conformity transfer of nano-patterns from the template to the wafer. It is experimentally shown that this loading process can effectively reduce the residual resist thickness while maintaining a uniform residual resist and non-distorted transfer of nano patterns to the resist coated wafer, and a high-conformity of 100nm feature can be achieved.