Fabrication and characterization of silicon nitride thin film planar waveguides produced by RF magnetron sputtering technique

Silicon nitride based planar waveguides play an important role in biosensing applications. Conventional fabrication of silicon nitride waveguides utilizes the chemical vapor deposition (CVD) technologies. Silicon nitride waveguide abrication through magnetron sputtering is still unexplored and a few literatures are available only on microelectronic and optoelectronic applications. In current study, the silicon nitride thin film planar waveguides were fabricated on SiO2 coated silicon substrates by RF magnetron sputtering technique. Sputtering power, sputtering pressure and target to substrate distance was varied from 100 to 300 W, 5 to 15 mTorr and 8 to 14 cm respectively to investigate the influence of sputtering parameters on film properties. The deposited films were characterized with FESEM, AFM and surface profile to observe the surface morphology. The structure and composition of deposited thin films were characterized with XRD and EDX spectroscopy techniques respectively. Optical properties such as refractive index and optical transmission were investigated through spectral reflectance and UV-VIS spectroscopy techniques respectively. After a detailed analysis, suitable sputtering parameters were selected as sputtering power 300 W, sputtering pressure 5 mTorr and target to substrate distance 14 cm to fabricate the asymmetric planar waveguide. The purpose of this fabrication was to investigate the optical propagation and to measure the propagation loss using prism coupling technique. The optical properties and thickness was determined first using spectroscopic ellipsometry technique. The thickness of waveguide was intended to greater than 400 nm as a requirement of prism coupling technique. The fabricated waveguide demonstrated a successful propagation of light at wavelength, λ = 448 nm and 633 nm. The estimated loss at 633 nm was 20 – 25 db/cm. This study supports the possibility of producing silicon nitride thin film planar waveguides by RF magnetron sputtering technique

Name dc:type.qualificationname

phd

Level dc:type.qualificationlevel

doctoral

Grantor dc:publisher.institution

Universiti Tun Hussein Onn Malaysia

Year dc:date.issued

2016

Author dc:creator

• Majeed, Uzair

• TP200-248 Chemicals: Manufacture, use, etc.

Language dc:language

en