Analysis of I-V-T Characteristics of Au/n-InP Schottky Barrier Diodes with Modeling of Nanometer-Sized Patches at Low Temperature

The current-voltage (I-V) characteristics of inhomogeneous Au/n-InP Schottky barrier (SB) diodes have been investigated in the temperature range of 100K to 300K, and detailed numerical simulation study carried out using a physical device simulator. The experimental I-V curves for the diode in both forward- and reverse-bias conditions were fit to explain the current transport mechanisms at low temperature. Tunneling current flows through the native oxide and nanometer-sized patches embedded at the Au/n-InP interface. These patches result in a lower (local) barrier height which is temperature dependent and responsible for the diode current behaviors in the low-bias regime. The patch area is on the order of one-millionth of the total diode area, and the SB is between 0.01eV and 0.3eV in the patch region. The simulation results are in good agreement with the measurements in the whole explored current range extending over six orders of magnitude.