Investigation of amorphous SiOx layer on gold surface for Surface Plasmon Resonance measurements
Résumé
The present study demonstrates that thin layers of amorphous silicon oxide (SiOx) grown by inductivelycoupled
plasma enhanced chemical vapor deposition (ICPECVD) technology at lower temperatures can be
successfully combined with biosensors. In particular, gold-amorphous silica (Au/SiOx) interfaces were investigated
for their potential applications as a low-cost Surface Plasmon Resonance (SPR) sensor chip.
ICPECVD silicon dioxide films up to 25 nm-thick were deposited at different pressure. Details of the SiOx
thin layer properties in terms of refractive index, deposition rate, roughness, chemical bonds, Si2p and
O1s bending energies, residual stress and contact angle were studied. The refractive index was found to decrease
with increasing pressure for all the films. The depositions rates were lower for films deposited at
higher pressures. We report here on the fabrication and characterization of stable and good reliabilities of
SiOx deposited at two temperature 80 °C and 130 °C at pressures ranging from 2 Pa to 20 Pa. The results
show that the SPR responses were very sensitive to any changes in the deposition parameters. In this
study, we have shown that SiOx has good potential for further developments, as a wideband biosensor application
with a higher sensitivity in SPR response.