Low-loss silicon waveguides with sidewall roughness reduction using a SiO2 hard mask and fluorine-based dry etching

Dong Ho Lee, Sung Joong Choo, Uiseok Jung, Kyung Woon Lee, Kwang Woong Kim, Jung ho Park

Research output: Contribution to journalArticle

22 Citations (Scopus)

Abstract

High optical field confinement-possible silicon waveguides are used in various fields. The performance of a silicon waveguide depends on its sidewall roughness, which is responsible for scattering loss. The fabrication process for a silicon waveguide with a smooth sidewall for low loss was studied. The propagation loss of an optical silicon waveguide was reduced by using a SiO2 hard mask and reactive ion etching (RIE) with fluorine gases. The sidewall angle was controlled by Si etching with a SF6 and CF4 gas mixture. The thickness of the SiO2 hard mask affects the sidewall smoothing treatment. The roughness of the sidewall was reduced in the SiO2 etching process with a CF4 and O2 gas mixture as the thickness of the SiO2 hard mask was increased. The minimum propagation loss (0.89 dB cm-1) of the fabricated silicon waveguide was achieved by using the fabrication method introduced in this paper.

Original languageEnglish
Article number015003
JournalJournal of Micromechanics and Microengineering
Volume25
Issue number1
DOIs
Publication statusPublished - 2015 Jan 1

ASJC Scopus subject areas

  • Mechanical Engineering
  • Electrical and Electronic Engineering
  • Mechanics of Materials
  • Electronic, Optical and Magnetic Materials

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