Numerical simulation of the electrical current transport in a metal-ultra thin insulating layer-InP epitaxial layer junction

A new approach to the numerical simulation of the electrical current transport in a tunnel MIS epitaxial diode was developed. The theoretical model proposed took into account a voltage dependence distribution of interface states and the effect of the interface states on the oxide potential and included the barrier lowering due to the image force, the hole and electron tunneling currents through the ultra thin insulating layer, the surface-state current, the minority-carrier diffusion current and exact formula for the generation-recombination current. The theoretical analysis shows that none of electrical current mechanisms could dominate over the entire voltage range studied in this work (-1.0 V⩽V⩽0.5 V). Therefore, all the current components must be included. The verification for our theory was done by comparing the value of the barrier height at zero bias (φ_b0) and the position of peak value of the rectification ratio, as a function of shallow dopant concentration (N_A), with those reported in the literature and extracted from the I-V data. Excellent agreement between the experimental and numerical results strongly support the validity of our theoretical expression for the I-V characteristics. For an Au/p-InP epitaxial MIS diode, our results indicated that the values of φ_b0 is a linear function of the metal work function (φ_m)