Numerical Modeling of Schottky Barrier Diode Characteristics

Abstract

Herein, a comprehensive model is presented for the calculation of entire current–voltage (IV) characteristics of Schottky contacts (SCs). This treatment allows to analyze in detail the physical and technological origins of empirical fit parameters like the ideality factor. This model considers variations of the semiconductor net doping density in growth direction and barrier height inhomogeneities. The only input parameters required are the doping profile, the mean value, and the standard deviation of the barrier height distribution as well as material parameters. As measuring conditions like the integration time impact measured IV characteristics, similar sweep parameters as applied during a measurement are included in the model and proven to be necessary for the understanding of charging currents and the shift of the voltage for zero current. Using this model, various nonidealities reported in literature are explained. Further, the influence of differently doped interfacial layers on the characteristics is studied. Finally, the model is applied to multiple datasets of IV characteristics of SCs on different materials published in literature and from this laboratory, enabling a fundamental understanding of the origins of the nonidealities observed as well as the distinction between the contributions of different transport mechanisms to the total current.