Shear-solvo defect annihilation of diblock copolymer thin films over a large area

Abstract

Achieving defect-free block copolymer (BCP) nanopatterns with a long-ranged orientation over a large area remains a persistent challenge, impeding the successful and widespread application of BCP self-assembly. Here, we demonstrate a new experimental strategy for defect annihilation while conserving structural order and enhancing uniformity of nanopatterns. Sequential shear alignment and solvent vapor annealing generate perfectly aligned nanopatterns with a low defect density over centimeter-scale areas, outperforming previous single or sequential combinations of annealing. The enhanced order quality and pattern uniformity were characterized in unprecedented detail via scattering analysis and incorporating new mathematical indices using elaborate image processing algorithms. In addition, using an advanced sampling method combined with a coarse-grained molecular simulation, we found that domain swelling is the driving force for enhanced defect annihilation. The superior quality of large-scale nanopatterns was further confirmed with diffraction and optical properties after metallized patterns, suggesting strong potential for application in optoelectrical devices.

Developing Anisotropy in Self‐Assembled Block Copolymers: Methods, Properties, and Applications

“…Additionally, reducing the defect density of BCP films is of paramount importance for their practical implantation into microelectronic applications, which has been explicitly discussed in many research articles. [543][544][545] Nevertheless, these emerging techniques provide exciting new opportunities to hasten the leap from research lab to large-scale manufacturing.…”

Defect recognition in line-space patterns aided by deep learning with data augmentation

“…The experimental dataset of 575 L/S pattern SEM images was acquired by performing experiments on cylinder-forming block copolymers. The experimental protocol details are published in a previous paper by Kim et al 19 In summary, once block copolymers are spin coated, the dual processing steps of shear alignment and solvent vapor annealing (SVA) in sequence were performed. The shear aligned BCP thin film obtained by applying shear stress with a cured polydimethylsiloxane pad undergoes SVA treatment in a glass chamber at room temperature.…”

“…The SEM dataset was collected after carrying out experiments using cylinder forming block copolymers under shear-solvo annealing conditions. 19 The numbers of convolutional layers and filters in a network were optimized for the network's accuracy. Further examination of various activation functions and different loss functions was implemented.…”

Directed Self-Assembly of Block Copolymers for the Fabrication of Functional Devices

“…Additionally, recent research on DSA has also been greatly focused on the study, understanding and mitigation of defects [ 98 , 99 , 100 , 101 , 102 , 103 , 104 , 105 , 106 , 107 ]. Minimization of defects is crucial for the incorporation of DSA into high-volume manufacturing, either as a primary patterning option or in combination with already established techniques like DUV or EUV.…”