The evidence for a preferential growth of a MnAs thin film on an as-preadsorbed Si 001/surface

We have investigated the initial stage of the MnAs film growth using photoelectron spectroscopy. Two types of p-type Si 001.substrates, with a Mn first layer and an As first layer were used. It is found that, a manganese silicide MnSi.and silicon oxide are formed around the interface when 1 ML of Mn is deposited first on Si. On the other hand, there is no silicon oxide formed at the interface when As is deposited first. Because of this As-passivation, the sample on which As is deposited first, has the sharper interface and the better film quality than the Mn-first sample. The interfacial alloys were analyzed by cross-sectional transmission electron microscope TEM.observation in the MnAsrSi system. To prevent the formation of interfacial alloys, we have tried to insert GaAs between MnAs and Si, resulting in the growth of MnAs film with improved film quality. q1998 Elsevier Science B.V. All rights reserved