MNTE CDTE INTERFACES CHARACTERIZATION - A MAGNETOOPTICAL STUDY/

This paper is devoted to the description of the interface between MnTe and CdTe, and to its magneto-optical properties. Indeed, the epitaxy of an heterojunction with these two II-VI semiconductors tends to form a few monolayers of Cd1-xMnxTe, which is a well known semimagnetic se miconductor very sensitive to a magnetic field [1], Thus, thanks to th e enhanced giant Zeeman splitting of the excitonic line observed in Mn Te/CdTe heterostructures under a magnetic field, we have a very powerf ul tool for probing the quality of this interface at the atomic scale. Systematic studies can be performed in order to analyse the influence of different growth conditions. It is shown that the magnetic propert ies of MnTe/CdTe interfaces grown at 280 degrees C are mainly due to a n exchange between Mn and Cd atoms that occurs, during thr growth, bet ween the last incorporated monolayer and the one being grown. Thanks t o a modelisation of the kinetics effects in the Mn segregation process , we can compute the Mn concentration profile monolayer by monolayer. We are then able to 'quantify' the experimentally observed influence o f the substrate temperature, of the impinging fluxes, of the growth me thod, and finally of the cations involved at the interfaces, on the Mn segregation process. By optimising all these parameters, we show how to control the abruptness of the MnTe/CdTe interfaces. (C) 1998 Elsevi er Science B.V.