Effect of amorphous SiC layer on electrical and optical properties of Al/a-SiC/c-Si Schottky diode for optoelectronic applications

In this work, we report on the study of the electrical and optical properties of amorphous silicon carbide (a-SiC)-based Schottky diodes for optoelectronic applications. A significant decrease of reflectivity and an enhancement of the passivating properties of more than 97% were reached after a-SiC layer deposition on silicon substrate. The deposited a-SiC film exhibits a dielectric constant of 2.143. Temperature effect on Schottky diode performances was carried out through the analysis of the current–voltage (I–V) characteristics at temperature range of 298–573 K. The ideality factor at room temperature was found to be 1.651, and it was improved to 1.132 when temperature was increased to 573 K. The calculated barrier height of the diode at room temperature was c 0.812 eV and it increased with temperature to reach 1.640 at 573 K. The change in the barrier height was attributed to the effective leakage current at high temperature. Shunt resistance R sh remained at around 85 KΩ along this range with a slight decrease at high temperature. Series resistance R s was sharply decreased from 520 Ω at room temperature to 45 Ω at 573 K. Thanks to the optical and electrical characterization performed, we have demonstrated the possibility of using such non hydrogenated amorphous SiC layers to improve the properties of based silicon Schottky diodes.