Barrier height enhancement of Ni/n-type InP Schottky contact using a thin praseodymium interlayer

A praseodymium interlayer with a thickness of 100 angstroms at Ni/InP Schottky contacts is shown to enhance the barrier height and reduce the reverse-bias current density. It is demonstrated that even though the contact was baked for 8 h at a temperature of 300 °C, its barrier height and reverse-bias current density could still be maintained at about 1.05 eV and 1.86×10^-10 A/cm² at -3 V, respectively. It is believed that praseodymium has high reactivity with oxygen to form praseodymium oxide with a wide band gap and a strong chemical bond. Similar to metal-insulator-semiconductor diodes, praseodymium can effectively increase the Schottky barrier height and reduce the reverse leakage current.