Epitaxial growth of NbN on an ultrathin MgO/semiconductor system

NbN epitaxial growth on an ultrathin MgO/semiconductor system was carried out by reactive sputtering. It was revealed that (100)-oriented NbN epitaxy was achieved on a (100)-oriented Si substrate by introducing a MgO buffer layer as thin as 5 Å at the interface. An interrupt-sputtering technique was newly conducted to obtain the epitaxial films, which were intermittently deposited by rf sputtering. A metal-insulator-semiconductor tunneling Schottky diode with epitaxial NbN was prepared using this technique, and evaluated in its current-voltage characteristics. Our study indicated that the NbN epitaxy mechansim can be explained by its growth on a (100) naturally oriented 5-Å MgO layer.