Capacitance–voltage characterization of AlN/GaN metal–insulator–semiconductor structures grown on sapphire substrate by metalorganic chemical vapor deposition

Abstract

Electrical characterization of AlN/GaN interfaces was carried out by the capacitance–voltage (C–V) technique in materials grown by metalorganic chemical vapor deposition. The high-frequency C–V characteristics showed clear deep-depletion behavior at room temperature, and the doping density derived from the slope of 1/C2 plots under the deep depletion condition agreed well with the growth design parameters. A low value of interface state density Dit of 1×1011 cm−2 eV−1 or less around the energy position of Ec−0.8 eV was demonstrated, in agreement with an average Dit value estimated from photoassisted C–V characteristics.