Investigation of the influence of the proximity effect and randomness on a photolithographically fabricated photonic crystal nanobeam cavity

Tomohiro Tetsumoto, Hajime Kumazaki, Rammaru Ishida, Takasumi Tanabe

Research output: Chapter in Book/Report/Conference proceedingConference contribution


Recent progress on the fabrication techniques used in silicon photonics foundries has enabled us to fabricate photonic crystal (PhC) nanocavities using a complementary metal-oxide-semiconductor (CMOS) compatible process. A high Q two-dimensional PhC nanocavity and a one-dimensional nanobeam PhC cavity with a Q exceeding 100 thousand have been fabricated using ArF excimer laser immersion lithography. These are important steps toward the fusion of silicon photonics devices and PhC devices. Although the fabrication must be reproducible for industrial applications, the properties of PhC nanocavities are sensitively affected by the proximity effect and randomness. In this study, we quantitatively investigated the influence of the proximity effect and randomness on a silicon nanobeam PhC cavity. First, we discussed the optical properties of cavities defined with one- and two-step exposure methods, which revealed the necessity of a multi-stage exposure process for our structure. Then, we investigated the impact of block structures placed next to the cavities. The presence of the blocks modified the resonant wavelength of the cavities by about 10 nm. The highest Q we obtained was over 100 thousand. We also discussed the influence of photomask misalignment, which is also a possible cause of disorders in the photolithographic fabrication process. This study will provide useful information for fabricating integrated photonic circuits with PhC nanocavities using a photolithographic process.

Original languageEnglish
Title of host publicationNanophotonics Australasia 2017
ISBN (Electronic)9781510613935
Publication statusPublished - 2017 Jan 1
EventNanophotonics Australasia 2017 - Melbourne, Australia
Duration: 2017 Dec 102017 Dec 13


OtherNanophotonics Australasia 2017



  • CMOS process
  • optical nanocavities
  • photolithography
  • Photonic crystal
  • silicon photonics

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Condensed Matter Physics
  • Computer Science Applications
  • Applied Mathematics
  • Electrical and Electronic Engineering

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