Effects of SiO2 hard masks on si nanophotonic waveguide loss for photonic device integration

Doris K.T. Ng, Qian Wang, Kim Peng Lim, Jing Pu, Kun Tang, Yicheng Lai, Chee Wei Lee, Seng-Tiong Ho

Research output: Contribution to journalArticlepeer-review

2 Scopus citations


As the basic building block for photonic device integration, silicon nanophotonic waveguide requires low-loss propagation for high-performance ultra-compact photonic device. We experimentally study silicon dioxide hard masks grown by two different methods, i.e., thermal oxidation and plasma-enhanced chemical vapor deposition (PECVD) for silicon nano-waveguides fabrication and their effects on the propagation loss. It is found that the denser and smoother quality of thermally grown silicon dioxide increases the etch selectivity against silicon and reduces the line edge roughness transferred to the silicon nano-waveguide sidewalls, hence resulting in a lower loss as compared with the PECVD silicon dioxide hard mask. With thermally grown silicon dioxide as a hard mask, the silicon nano-waveguides loss can be halved for a 650-nm-wide nano-waveguide, and the loss is comparable with a waveguide fabricated with a resist etch mask.

Original languageEnglish (US)
Article number6646203
Pages (from-to)70-73
Number of pages4
JournalIEEE Photonics Technology Letters
Issue number1
StatePublished - Jan 1 2014


  • Dielectric materials
  • Loss measurement
  • Optical waveguides

ASJC Scopus subject areas

  • Electronic, Optical and Magnetic Materials
  • Atomic and Molecular Physics, and Optics
  • Electrical and Electronic Engineering

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