Investigation of amorphous SiOx layer on gold surface for Surface Plasmon Resonance measurements

International audience; The present study demonstrates that thin layers of amorphous silicon oxide (SiOx) grown by inductivelycoupledplasma enhanced chemical vapor deposition (ICPECVD) technology at lower temperatures can besuccessfully combined with biosensors. In particular, gold-amorphous silica (Au/SiOx) interfaces were investigatedfor 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 SiOxthin layer properties in terms of refractive index, deposition rate, roughness, chemical bonds, Si2p andO1s bending energies, residual stress and contact angle were studied. The refractive index was found to decreasewith increasing pressure for all the films. The depositions rates were lower for films deposited athigher pressures. We report here on the fabrication and characterization of stable and good reliabilities ofSiOx deposited at two temperature 80 °C and 130 °C at pressures ranging from 2 Pa to 20 Pa. The resultsshow that the SPR responses were very sensitive to any changes in the deposition parameters. In thisstudy, we have shown that SiOx has good potential for further developments, as a wideband biosensor applicationwith a higher sensitivity in SPR response.