Growth of MnSi1.7 on Si(001) by MBE

The silicides of manganese most rich in silicon, the so-called higher manganese silicides (HMS) have a composition MnSix with x in the range from 1.67 to 1.75. This material group with a tetragonal crystal structure shows semiconducting electronic properties promising the application in thermoelectric devices (C.B. Viniing, Proceedings of the IX International Conference on Thermoelectrics, California Institute of Technology, Pasadena, 1991 249). This paper reports on structural and morphological properties of the HMS prepared on Si(0 0 1) by various MBE processes under UHV conditions. The deposition of Mn only as well as the codeposition of Mn and Si do not allow epitaxial growth of the HMS. But, after the preparation of a thin Mn template at room temperature, the codeposition of Mn and Si at high substrate temperatures results in the growth of epitaxial HMS. The fraction of epitaxially grown HMS strongly depends on the thickness of the template layer. The epitaxial relationship between the silicide and the Si has been determined by X-ray diffraction. (C) 2001 Elsevier Science B.V. All rights reserved.