The heterogenous integration of GaN thin-film metal-semiconductor-metal photodetectors onto silicon

Abstract

The heterogeneous integration of GaN thin-film metal-semiconductor-metal (MSM) photodetectors onto a host substrate of SiO/sub 2/-Si is reported. Thin-film GaN photodetectors were separated from the lithium gallate (LiGaO/sub 2/) growth substrate using selective etching, and contact bonded onto a SiO/sub 2/-Si host substrate. The thin-film MSMs exhibited a dark current of 13.36 pA and an UV photoresponse at 308 nm of 0.11 A/W at a reverse bias voltage of 20 V. This first demonstration of GaN thin-film device integration onto SiO/sub 2/-Si using a low-temperature integration process, combined with the advances in GaN material quality on LiGaO/sub 2/ substrates, enables the integration of GaN devices with Si circuitry for heterogeneously integrated systems.