Synthesis and Characterization of Nanocrystalline Silicon Carbide Thin Films on Multimode Fiber Optic by means 150 MHz VHF-PECVD

In recent years, a number of advantages such as modification of nano-crystalline thin films, the ability for low-temperature deposition processes, the controlling of process, as well as high efficiency and repeatability of process, were offered using plasma deposition technique [1]. Silicon carbide (SiC) as a leading candidate for the replacement of Silicon (Si) for hightemperature and power electronic devices has attracted more attention due to its mechanical robustness and chemical inertness at elevated temperatures [2,3]. It also becomes an attractive and promising material for fabricating high-temperature pressure sensors. Furthermore, the wide band gap, a high-breakdown electric field, fast response time, mechanical strength and a low leakage current of SiC made it a better material than silicon in high-temperature electronic applications [4-8]. In addition, the semiconductor coating layers such as SiC and Si have features apart from sensitivity enhancement of the optical fiber, such as fiber protection, tunability of the resonance wavelength region and bio-chemical compatibility of the sensor [9,10]. According to a study reported by Kumar et al. [3], the performance of an optical fiber sensor fabricated using surface plasmon resonance (SPR) technique can be enhanced by using silicon carbide (SiC). Nowadays, the plasma enhanced chemical vapor deposition (PECVD) [11-13], reactive magnetron sputtering [14], hot wire chemical vapor deposition (HW-CVD) [15] and radio frequency plasma enhanced chemical vapor deposition (RF-PECVD) systems [16] are common techniques that are used to grow the nanocrystalline SiC films. PECVD is the most widely used method for the growth of the SiC thin films because of its lower working temperature compared to the other techniques.