Electrical characterization of silicon nitride interlayer-based MIS diode

In this study, silicon nitride (Si 3 N 4 ) thin film on p-type GaAs wafer was deposited by RF magnetron sputtering. The surface morphology of Si 3 N 4 /GaAs structure was analyzed by atomic force microscopy (AFM). The electrical characteristics of the fabricated Au/Si 3 N 4 /p-GaAs metal–insulator-semiconductor (MIS) diode were investigated by using current–voltage ( I – V ) measurements at room temperature. The electronic parameters such as ideality factor (n) and barrier height (Φ bo ) of the MIS diode were derived using thermionic emission (TE). The Φ bo was also extracted from Norde method. The barrier height values obtained from both TE and Norde were found to be in harmony with each other. The interface state density ( N ss ) and series resistance ( R s ) parameters of the MIS diode were determined from the measured I – V data. In addition, the dominant current conduction mechanisms of the MIS diode were also investigated by forward bias ln( I F ) − ln( V F ) and reverse bias ln( I R ) − V R 0.5 plot. At high forward bias, the current conduction was associated with the space charge limited current (SCLC). At reverse bias region, the current conduction was associated with the Schottky emission (SE).