Enhancement of Optical Response in Nanowires by Negative-Tone PMMA Lithography
Author(s)Charaev, Ilya; Dane, Andrew; Agarwal, Akshay; Berggren, Karl K.
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The method of negative-tone polymethyl methacrylate (PMMA) electron-beam lithography is investigated to improve the performance of nanowire-based superconducting detectors. Using this approach, the superconducting nanowire single-photon detectors (SNSPDs) have been fabricated from 5-nm-thick NbN film sputtered at room temperature. To investigate the impact of this process, SNSPDs were prepared by positive-tone- and negative-tone-PMMA lithography, and their electrical and photodetection characteristics at 4.2 K were compared. The SNSPDs made by negative-tone-PMMA lithography show higher critical-current density and higher photon count rate at various wavelengths. Our results suggest a higher negative-tone-PMMA technology may be preferable to the standard positive-tone-PMMA lithography for this application. Keywords: Films; Nanowires; Lithography; Temperature measurement; Detectors; Current measurement; Niobium compounds
DepartmentMassachusetts Institute of Technology. Department of Electrical Engineering and Computer Science
IEEE Transactions on Applied Superconductivity
Institute of Electrical and Electronics Engineers (IEEE)
Charaev, Ilya et al "Enhancement of Optical Response in Nanowires by Negative-Tone PMMA Lithography." IEEE Transactions on Applied Superconductivity 29, 5 (August 2019): 1100905 ©2019 IEEE.