掩膜板凸出环隔离压缩式纳米压印施压气体的研究

Analysis of gas isolation by prominent O-ring on the mold in compressional gas cushion press nanoimprint lithography

在半导体微纳加工技术中,纳米压印由于具备低成本、高产出、超高分辨率等诸多优势而备受研究者和半导体厂商的青睐,有望成为下一代光刻技术的重要备选支撑技术之一.然而在其施压流程中,由于气体诱捕或陷入所造成的气泡缺陷问题直接关系到图案复制的成功率和完整性,因此避免气泡缺陷,阻止气泡进入模穴是亟待解决的关键问题.提出一种适用于在气体环境中进行气压压缩式纳米压印工艺并避免气体进入掩膜板基板间隙的方法.采用带有刻蚀一定宽度凸出环的掩膜板,凸出环与基板形成环板毛细缝隙,图形转移介质流体在其中形成毛细液桥,使掩膜板-介质-基板形成独立的封闭腔,转移介质黏附力所产生的静摩擦力及介质流体表面张力所诱导的毛细力抵抗施压气体,有效地阻止气体进入空穴形成气泡缺陷.通过理论解析推导求出针对具有不同表面特性转移介质流体的凸出环有效宽度,为掩膜板制备提供理论依据.

Nanoimprint lithography has the advantages of low-cost, high-throughput, ultrahigh resolution, which could make it one of the next generation lithography technologies. However, the bubble-defect is always a problem which may damage the duplicate patterns, so it is an urgent issue to propose effective solutions. A novel methods, which is suitable for compressional gas cushion press nanoimprint lithography in gas atmosphere and could prevent gas from entering the gap between mold and substrate, is presented here. The annular plate capillary gap formed between the smooth substrate and the prominent O-ring processed by etching the original mold would be filled with the fluid medium. The capillary liquid bridge between the O-ring and substrate produces a closed cavity. The stiction induced by adhesion force and the capillary force induced by air-liquid surface tension could resist the compressed gas and avoid the bubble defect. The effective widths of the prominent O-ring, which are different for various fluids with different surface properties, are deduced by theory analysis. The analysis results provide theoretical basis for the preparation of the mold.