Plasmonic Waveguide Lithography for Patterning Nanostructures with High Aspect-Ratio and Large-Area Uniformity

plasmonic waveguide;nanomanufacturing;UV lithography;spatial filtering;hyperbolic metamaterial;next-generation lithography;Electrical Engineering;Engineering (General);Physics;Engineering;Science;Applied Physics

Chen, XiNorris, Theodore B ;

University of Michigan

关键词: plasmonic waveguide;    nanomanufacturing;    UV lithography;    spatial filtering;    hyperbolic metamaterial;    next-generation lithography;    Electrical Engineering;    Engineering (General);    Physics;    Engineering;    Science;    Applied Physics;   

Others  :  https://deepblue.lib.umich.edu/bitstream/handle/2027.42/144126/sxichen_1.pdf?sequence=1&isAllowed=y

瑞士|英语

来源: The Illinois Digital Environment for Access to Learning and Scholarship

【 摘 要 】

The rapid development of the semiconductor industry in the past decades has driven advances in nano-manufacturing technologies towards higher resolution, higher throughput, better large-area uniformity, and lower manufacturing cost. Along with these advancements, as the size of the devices approaches tens of nanometers, challenges in patterning technology due to limitations in physics, equipment and cost have quickly arisen. To solve these problems, unconventional lithography systems have attracted considerable interest as promising candidates to overcome the diffraction limit. One recently evolved technology, plasmonic lithography, can generate subwavelength features utilizing surface plasmon polaritons (SPPs). Evanescent waves generated by the subwavelength features can be transmitted to the photoresist (PR) using plasmonic materials. Another approach of plasmonic lithography involves the use of hyperbolic metamaterial (HMM) structures, which have been studied intensively because of their unique electromagnetic properties. Specifically, epsilon near zero (ENZ) HMMs offer the potential to produce extremely small features due to their high optical anisotropy. Despite the advancements in plasmonic lithography, several key issues impede progress towards more practical application, which includes shallow pattern depth (due to the evanescent nature of SPPs), non-uniformity over a large area (due to the interference of multiple diffraction orders) and high sensitivity of the roughness on the films and defects on the mask. The light intensity in the PR is very weak which results in an extremely long exposure time. To this end, this dissertation is dedicated to plasmonic lithography systems based on SPP waveguides and ENZ HMMs for patterning nanostructures with high aspect-ratio and large-area uniformity.New schemes are exploited in this thesis to address these challenges. Lithography systems based on a specially designed waveguide and an ENZ HMM are demonstrated. By employing the spatial filtering properties of the waveguide and the ENZ HMM, the period, linewidth and height of the patterns can be well controlled according to various design purposes. Periodic structures were achieved in both systems with a half-pitch of approximately 50 ~ 60 nm, which is 1/6 of the exposure wavelength of 405 nm. The thickness of the PR layer is around 100 ~ 250 nm, which gives an aspect-ratio higher than 2:1. The subwavelength patterns are uniform in cm2 areas. In addition to the design principle, various numerical simulations, fabrication conditions and corresponding results are discussed. The design principle can be generalized to other materials, structures and wavelengths. The real-world performance of the lithography system considering non-idealities such as line edge roughness and single point defect is analyzed. Comparisons between the plasmonic systems based on different design rules are also carried out, and the advantages of the spatial frequency selection principle is verified.The plasmonic waveguide lithography systems developed in this dissertation provide a technique to make deep subwavelength features with high aspect-ratio, large-area uniformity, high light intensity distribution, and low line-edge-roughness for practical applications. Compared with the previously reported results, the performance of plasmonic lithography is drastically improved. A plasmonic roller system combining the photo-roller system and plasmonic lithography is also developed. This plasmonic roller system can support a continuous patterning with a high throughput for cost sensitive applications. Several potential applications of the plasmonic materials including near field spin Hall effects and a particle based Lidar design are explored. Other advances towards plasmonic functional devices including silicon (Si) nanowire (NW) arrays, light-thermal converters and plasmonic lasers are also reported.