GaN metal-semiconductor-metal photodetectors grown on lithium gallate substrates by molecular-beam epitaxy

The growth, fabrication, and characterization of ultraviolet metal-semiconductor-metal (MSM) GaN photodetectors grown on LiGaO2 by molecular-beam epitaxy are reported herein. GaN/LiGaO2 material with dislocation densities of approximately 10(8) cm(-2) and x-ray diffraction (00.4) full width at half maximum of 75 arcsec results in MSMs showing high responsivity, 0.105 A/W, at a reverse bias voltage of 20 V at 308 nm, and low dark currents of 7.88 pA at a 60 V reverse bias. Given the etch selectivity of the GaN/LiGaO2 system and the excellent performance of these devices, GaN device integration onto alternative substrates appears promising. (C) 2001 American Institute of Physics.