John Dallesasse

University of Illinois at Urbana-Chamapign
  • Transfer of Thin Film Gallium Phosphide onto Glass for Integrable Optical Filters

    Maanav Ganjoo, University of Illinois, Urbana-Champaign
    John Carlson, University of Illinois, Urbana-Champaign
    Saoud Al-Mulla, University of Illinois, Urbana-Champaign
    James Brown, University of Illinois, Urbana-Champaign
    Brian Cunningham, University of Illinois, Urbana-Champaign
    John Dallesasse, University of Illinois at Urbana-Chamapign

    A single-layer optical filter made from thin film gallium phosphide (GaP) is envisioned and a fabrication flow is outlined, with current progress on process development reported. Ion-implantation is simulated and performed on bulk GaP with He+, followed by a field-assisted thermal bonding technique that simultaneously bonds a thin GaP film onto a borofloat glass substrate and removes the GaP substrate. The resulting thin films have consistent thickness, both within and between runs, and RMS surface roughness of < 10 nm. Dry-etch processes that further reduce the thin film material are characterized and designs for etching gratings into them are developed. This process is shown to be a reliable means of creating thin films of consistent thickness and smoothness in GaP, for the purpose of establishing visible wavelength filters for spectroscopic applications.

    Download Paper