Studies of n-SiCN/p-Si diode for low cost and high temperature ultraviolet light sensing applications

In this paper, we study of n-SiCN/p-Si heterojunction for low cost and high temperature ultraviolet (UV) detecting applications in details. The cubic crystalline SiCN film was deposited on p-Si (100) substrate using C3H8 for carbon source by rapid thermal chemical vapor deposition (RTCVD) technique. The developed device has a high photo/dark current ratio (PDCR) of 32.7 under room temperature (25 °C) with and without an irradiation of 254 nm, 0.5 mW/cm2 power UV light source. Even up to 175 °C, the PDCR can keep at 3.03. Although, these results are less than the reported n-SiCN/PS/p-Si diode with a porous Si (PS) as buffer layer; however, it still better than the reported ZnO on GaAs substrate or ZnO nanowires on p-silicon substrate UV detectors. Without the PS layer, one can simplify preparing process and thus improving yield. More important, it immunizes some interface reliability issues, due to the absorption of ambient gases by the higher reactive PS surface. Therefore, the new developed n-SiCN/p-Si heterojunction has a better potential for the low cost and high temperature UV sensing applications.