Graphitic Carbon Nitride (g- C3N4)/Al2O3Heterostructure as Double Dielectric: A Comparative Study in MIS Based on a-IGZO

Abstract

We present a systematic study of how graphitic carbon nitride (g-C3N4) in combination with Al2O3 can be used as a double dielectric to control threshold and flat band voltage in capacitance-voltage (C-V) characteristics of an a-IGZO metal-insulator-semiconductor (MIS) device fabricated on ITO substrate. We study temperature dependence of C-V characteristics for Al2O3 based MIS structures with and without g-C3N4 in the oxide. The effective dielectric constants are estimated in both cases. We show that g-C3N4 in combination with Al2O3 can be used as an effective dielectric with larger relative permittivity than either of them. It also leads to positive threshold shift without affecting the active interface at the semiconductor. The carrier density in the semiconductor is measured from the depletion region showing small variation with respect to frequency and temperature.