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The behaviors of ZnO films using t-BuOH and H2O as oxygen precursors were investigated.Despite the fact that both t-BuOH and H2O are of lower activity,the ZnO epilayer has a higher growth rate when t-BuOH is used as oxygen precursor,due to its more effective prevention of the gas phase pre-reaction.Compared with H2O,ZnO epilayer get a better crystal quality by using t-BuOH as oxygen precursor.And the Hall mobility up to 37.0 cm2·V-1·s-1 is achieved in the flim where t-BuOH is used as oxygen precursor.The research shows that t-BuOH is more suitable for oxygen precursor of the MOCVD growth of ZnO epilayer.

The characteristics of a ZnO/ZnMgO heterostructure field-effect transistor(HFET) were reported in this paper.The HFET was grown on α-plane sapphire substrate by metal-organic vapor phase epitaxy(MOVPE) technology,and was fabricated by a conventional photolithography technique combined with wet etching.The experiment results indicated that the HFET was an n-channel depletion type with a transconductance of 180 μS·mm-1 and mobility of 182 cm2·V-1·s-1 at room temperature.The property was limited by leakage current through the SiO2 gate insulator.At low temperature,the performance was improved due to the reduced leakage current.

ZnMgO films were grown on the Al_2O_3(sapphire)and ZnO substrates by metal-organic chemical vapor deposition(MOCVD)under different pressures.By analyzing the crystal structure,surface properties, optical and electrical properties of ZnMgO films,We found that different substrates and pressures have an important influence on growth and properties of ZnMgO films.Both high pressure of 5 kPa and ZnO substrate are better for Mg doping in ZnMgO.