Crystalline Silicon Carbide Thin Films for Ultraviolet Detection

Abstract

UV light detection has a lot of applications including secured satellite communication, solar and celestial observation and biological imaging. Wide bandgap materials are used to sense UV light. SiC is an excellent material for UV detection, having properties like high hardness, chemical inertness, thermal stability, high breakdown voltage etc. making it a very reliable and stable material for use in harsh/unknown environments. Growing SiC is a difficult task as it shows 250 different crystal structures and needs very high temperature to form crystalline film. Most of the studies use SiH4 (toxic) and other gaseous precursors for growth of SiC. We are proposing formation of crystalline SiC thin film with DC magnetron sputtering using highly pure, naturally and commercially abundant Silicon, Argon and Methane at relatively lower temperature. The technique is well known in industry and is compatible with silicon technology. SiC thin films were grown on Si Substrate. For the study of formation of crystalline films, we varied the deposition parameters. Flow rate of methane inside the chamber and DC power supplied to the target were varied to observe the change in film’s bonding, structure and crystallinity. Deposited films were characterized using FTIR, Raman, X-Ray Diffraction, Optical profilometer and UV Visible spectroscopy. Films grown were found to be polycrystalline and the study gave the clear picture to get high quality reproducible cubic SiC thin films. Optimized films were used to make a heterostructure of Al/SiC/Si/Al configuration and a planar structure of Al/SiC/Al on quartz substrate to observe the response in UV region. Study proposes that the deposited film could be used for UV detection in various applications