Mosaic superstructure in manganese silicide films on Si(111)-(3×3):Bi-α

Thin films of Mn are grown on Si(111)-(3×3):Bi-α. The film growth is epitaxial. Flat films with deep holes are observed. The film material is MnSi. The surface of the epitaxial MnSi films is modulated in height with a periodicity of about 200 Å due to the mismatch between the MnSi and the underlying Si(1 1 1) substrate. The observed modulation is clearly due to morphology since scanning tunneling microscopy and low-energy electron diffraction lead to consistent results. A likely growth model is discussed.