Influence of substrate temperature on incorporation of magnesium into Zn1-xMgxO layers growth by molecular beam epitaxy

Plasma-assisted molecular beam epitaxy growth of ZnO and Zn1-xMgxO epilayers on Al2O3 (11-20) substrates is described. The influence of the substrate temperature on the growth rate and magnesium concentration in Zn1-xMgxO epilayers was studied in detail. It was found that the composition of magnesium in Zn1-xMgxO epilayers increased with increasing substrate temperature. The composition variation in the alloys as a function of the growth temperature could be explained by the difference of vapor pressure of Mg and Zn at high growth temperature. Theoretical approaches to surface evaporation of metal atoms under different growth condition are difficult. Here, we describe an uncomplicated method determine quantities experimental to obtain. These results can be extended to other types of ternary or quaternary materials grown by MBE technique. (C) 2018 Elsevier B.V. All rights reserved.