Influence of electronic transmission on the electrical transport properties in metal-semiconductor contacts

A Pt/Si Schottky diode was prepared by depositing thin-film Pt on Si (100) via RF magnetron sputtering. The I-V characteristics of the nano-Schottky structure were measured by conductive-AFM (CAFM) and probe-based measurement, where nano- and micro-size tip was used, respectively. Result from both measurements showed the rectifying behaviors, whereas the leakage current detected by CAFM is about six orders of magnitude larger than that detected by the micromeasurement. It was proposed that this electronic transport discrepancy is mainly ascribed to the different electronic transmission. In order to reveal the characteristics of the Schottky junction, a thermionic emission (TE) model and thermionic-field emission (TFE) model were applied for the I-V data fitting. It was proved that the result can be well fitted by the TE model, with an ideality factor (IF) n = 1-2 and barrier height (BH) 0.75-0.85 eV, indicating this Schottky diode approximates to an ideal Schottky diode (n = 1).