Capacitance--voltage characteristics of /[Al.sub.2] [O.sub.3]/n-GaN MIS structures

The capacitance-voltage characteristics of (Al/Ti)/[Al.sub.2][O.sub.3]/n-GaN metal--insulator--semiconductor (MIS) structures are measured and analyzed. n-Type GaN films are grown on sapphire (0001) substrates by the metal-organic chemical vapor deposition method. An aluminum-oxide layer with a thickness of 60 nm is deposited onto the surface of GaN by the method of atomic-layer deposition from the gas phase. Metallic contacts are deposited by the electron-beam evaporation of titanium and aluminum in vacuum. According to the measurement results, the breakdown-field strength of the oxide, its dielectric constant, and the integrated electron density of states at the oxide--semiconductor interface are 5 x [10.sup.6] V/cm, 7.5, and 3 x [10.sup.12] [cm.sup.-2], respectively. DOI: 10.1134/S106378261508009