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 journalArticlepeer-review

27 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

Keywords

  • CF
  • SF
  • SiO
  • reactive ion etching
  • silicon waveguide
  • silicon-on-insulator

ASJC Scopus subject areas

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

Fingerprint

Dive into the research topics of 'Low-loss silicon waveguides with sidewall roughness reduction using a SiO<sub>2</sub> hard mask and fluorine-based dry etching'. Together they form a unique fingerprint.

Cite this