The electrical properties of Au/AlN/Au metal-insulator-metal (MIM) capacitors and Au/AlN/n-Si/Ga metal-insulator-semiconductor (MIS) diodes have been investigated by capacitance-voltage (CV) and current-voltage (IV) techniques. MIM capacitors, fabricated by magnetron sputtering, and MIS diodes prepared by molecular beam epitaxy showed improved electrical properties after annealing at 200 degrees C in a nitrogen ambient. For MIM devices prepared with a sculptured AlN film, there was a remarkable improvement in electrical properties after annealing. The dielectric constant for MIM devices ranged from 9.5 to 11. Ionic conduction with activation energies of 0.10, 2.0 and 4.0 eV was identified as a possible conduction mechanism. As deposited MIS devices showed characteristic diode behavior with a turn-on voltage of 0.5 V but presented a breakdown field of only 0.21 MV/cm. After annealing, only the dynamic impedance of the device was increased. A Frenkel-Poole model of charge transport was identified. From cyclic CV measurements on annealed sample the maximum capacitance (616 pF), dielectric constant (12) and the density of trapped charge (1.6 x 10(11) cm(-2)) was obtained. (C) 2013 Elsevier Ltd. All rights reserved.