Mg2Si1-xGex layers were grown on silicon-germanium substrates by heat treatment of the substrates in Mg vapor. The layers were grown by an interdiffusion process between the deposited Mg atoms and the substrates. It has been demonstrated that smooth and continuous layers can be grown with an abrupt layer/substrate interface, and no Kirkendall void is formed. It was found that the Ge contents of the grown layers almost agree with those of the substrates used without any phase separation and/or additional compositional deviation caused by the thermal treatment. (c) 2005 Elsevier B.V. All rights reserved.