Lundy Ross, Flynn Shauna P, Cummins Cian, Kelleher Susan M, Collins Maurice N, Dalton Eric, Daniels Stephen, Morris Michael A, Enright Ryan
Thermal Management Research Group, Efficient Energy Transfer (ηET) Dept., Bell Labs Ireland, Nokia, Blanchardstown Business & Technology Park, Snugborough Rd., Dublin 15, Ireland.
National Centre for Plasma Science and Technology, Dublin City University, Glasnevin, Dublin 9, Ireland.
Phys Chem Chem Phys. 2017 Jan 25;19(4):2805-2815. doi: 10.1039/c6cp07633e.
Molecular self-assembling block copolymers (BCPs) have shown promise as a next generation bottom-up lithography technology. However, a critical step in advancing this approach is the elimination of polymer dewetting due to bulk solvent nucleation and thermodynamically driven film rupture that can occur during the solvent vapor annealing process. We report on the pattern formation via phase segregation of spin coated diblock copolymer films through the investigation of annealing parameters in the limit of high solvent vapor saturation conditions that results in wafer-scale patterning without observing polymer dewetting defects. Specifically, the work addresses polymer dewetting in diblock copolymer nanodot templates through the use of a "neutral" functionalization layer and the development of a custom-built solvent vapor annealing chamber to precisely control saturation conditions. Furthermore, the long anneal times (4 h) using a standard static solvent vapor annealing procedure were reduced to ∼15-30 minutes with our dynamic solvent vapor annealing system for the high χ, cylindrical forming poly(styrene)-block-poly(4-vinyl-pyridine) [PS-b-P4VP] diblock copolymer system. We discuss the kinetic mechanism governing the phase segregation process that highlights the small processing window bounded by long phase segregation timescales (≳1 min) on one side and the initiation of polymer film dewetting on the other. These results demonstrate a key step towards realizing a high fidelity, low cost BCP patterning technique for large-scale "bottom-up" feature definition at nanometer length scales.
分子自组装嵌段共聚物（BCPs）已展现出作为下一代自下而上光刻技术的潜力。然而，推进这种方法的关键一步是消除由于本体溶剂成核和在溶剂蒸汽退火过程中可能发生的热力学驱动的薄膜破裂导致的聚合物去湿现象。我们通过研究在高溶剂蒸汽饱和条件下的退火参数，报道了旋涂二嵌段共聚物薄膜通过相分离形成图案的过程，该条件导致晶圆级图案形成且未观察到聚合物去湿缺陷。具体而言，这项工作通过使用“中性”功能化层以及开发定制的溶剂蒸汽退火腔室以精确控制饱和条件，解决了二嵌段共聚物纳米点模板中的聚合物去湿问题。此外，对于高χ值、形成圆柱形的聚（苯乙烯）-嵌段-聚（4-乙烯基吡啶）[PS-b-P4VP]二嵌段共聚物体系，我们的动态溶剂蒸汽退火系统将使用标准静态溶剂蒸汽退火程序的长时间退火时间（4小时）缩短至约15 - 30分钟。我们讨论了控制相分离过程的动力学机制，该机制突出了由长相分离时间尺度（≳1分钟）在一侧界定以及聚合物薄膜去湿在另一侧引发所限定的小加工窗口。这些结果展示了朝着实现用于纳米长度尺度大规模“自下而上”特征定义的高保真、低成本BCP图案化技术迈出的关键一步。
