Selective-area growth of β-Ga2O3 nanowire films on nano-patterned Si(111) substrate by metal-organic chemical vapor deposition

ss-Ga2O3 nanowire films were prepared on Si(111) substrate by selective area growth (SAG) using metal-organic chemical vapor deposition (MOCVD). A large-area periodic nano-hole array TiN mask was fabricated. The effects of MOCVD process parameters on SAG were discussed by calculating Ga supersaturation. It was found that the SAG is closely related to the selective area nucleation and inhibition of lateral growth. Transmission electron microscopy confirmed that ss-Ga2O3 nanowires have a preferential orientation of the (002) crystal plane. The sample after in-situ O-2 annealing showed an x-ray diffraction intensity increase of (400), (002), and (-111) crystal planes. On this basis, P-Si/ss-Ga2O3 nanowire heterojunctions were fabricated and presented high resistance of the films. At a bias voltage of 20 V, the current decreased from 6.14 x 10(-6) to 2.25 x 10(-6) A. The MOCVD-based SAG paves a novel way to fabricate ss-Ga2O3 nanowire films with high surface-to-volume ratio and homogeneity.