Dielectrics for GaN based MIS-diodes

摘要

GaN MIS diodes were demonstrated utilizing AlN and Ga(sub 2)O(sub 3)(Gd(sub 2)O(sub 3)) as insulators. A 345 (angstrom) of AlN was grown on the MOCVD grown n-GaN in a MOMBE system using trimethylamine alane as Al precursor and nitrogen generated from a wavemat ECR N2 plasma. For the Ga(sub 2)O(sub 3)(Gd(sub 2) O(sub 3)) growth, a multi MBE chamber was used and a 195 (angstrom) oxide is E- beam evaporated from a single crystal source of Ga(sub 5)Gd(sub 3)O(sub 12). The forward breakdown voltage of AlN and Ga(sub 2)O(sub 3)(Gd(sub 2)O(sub 3)) diodes are 5V and 6V, respectively, which are significantly improved from (approximately) 1.2 V of schottky contact. From the C-V measurements, both kinds of diodes showed good charge modulation from accumulation to depletion at different frequencies. The insulator GaN interface roughness and the thickness of the insulator were measured with x-ray reflectivity.