Low-temperature epitaxial growth of Si and Ge and fabrication of isotopic heterostructures by direct ion beam deposition

Abstract

Direct ion beam deposition (IBD) is utilized to deposit isotopic thin films and heterostructures and to achieve high-quality epitaxial growth of 74Ge on Ge(100) and 30Si on Si(100) at temperatures as low as 400°C. Anomalous damage is observed during IBD at 400° and 600°C that results in a band of buried loops at depths 50 times normal and a defect-free region near the original surface. An unexplained doping effect is reported for epitaxial growth of Si on Si at 20-40 eV, 400°C where high-quality epitaxy occurs on n-type Si but amorphous films form on p-type.