Surface morphology evolution and optoelectronic properties of heteroepitaxial Si-doped β-Ga2O3 thin films grown by metal-organic chemical vapor deposition

Heteroepitaxial growth of conductive Si-doped beta-Ga2O3 films on c-plane sapphire substrates by metal-organic chemical vapor deposition (MOCVD) was successfully performed. The effect of Si content on the structural, morphological, electrical and optical properties of Si-doped beta-Ga2O3 films was investigated in detail. Distinctive surface morphology evolution of films depending on Si content was observed and presented. The Si-doped beta-Ga2O3 films exhibited high transmittance in the ultraviolet-visible regions. The temperature-dependent PL was carried out especially to discuss the photoluminescence properties of Si-doped beta-Ga2O3 films. More importantly, the results suggested that the conductivity of heteroepitaxial Si-doped beta-Ga2O3 films by MOCVD could be realized and controlled by adjusting the Si content. The minimum resistivity of 1.79 x 10(-1) Omega.cm was obtained for the films grown under the SiH4 flow rate of 0.08 sccm.