Microwave Irradiation Assisted Deposition of Ga2O3 on III-nitrides for deep-UV opto-electronics

Abstract

We report on the deposition of gallium oxide using microwave irradiation technique on III nitride epi layers. We also report on the first demonstration of a gallium oxide device, a visible blind deep UV detector, with GaN based heterostructure as the substrate. The film deposited in the solution medium, at less than 200 C, using a metalorganic precursor, was nanocrystalline. XRD confirms that as deposited film when annealed at high temperature turns polycrystalline beta gallium oxide. SEM shows the as deposited film to be uniform, with a surface roughness of 4 to 5 nm, as revealed by AFM. Interdigitated metal semiconductor metal MSM devices with Ni,Au contact exhibited peak spectral response at 230 nm and a good visible rejection ratio. This first demonstration of a deep-UV detector on beta-gallium oxide on III nitride stack is expected to open up new possibilities of functional and physical integration of beta gallium oxide and GaN material families towards enabling next generation high performance devices by exciting band and heterostructure engineering.