GROWTH OF EPITAXIAL MGO FILMS ON SB-PASSIVATED (001)GAAS - PROPERTIES OF THE MGO/GAAS INTERFACE

The growth of epitaxial MgO films on Sb-passivated (001)GaAs using pulsed laser deposition has been investigated. The temperature at which the Sb-passivation layer was desorbed was found to have a significant effect on the interfacial properties of MgO/GaAs heterostructures. Heating the substrates to 350-380°C in vacuum resulted in a (1×3) GaAs surface reconstruction suitable for the growth of epitaxial MgO films. However, residual Sb was found to persist on the GaAs surface at temperatures as high as 500°C. MgO growth after Sb desorption at 350-380°C resulted in a nonuniform interfacial layer which varied in thickness from ∼0.1 to 1.5 nm, whereas substrates heated to 500°C prior to MgO growth displayed abrupt interfaces. Capacitance-voltage measurements indicated a qualitative difference in the interfacial electronic properties for the two cases.© 1995 American Institute of Physics.