EPITAXIAL SILICIDES - NEW RESULTS FROM RHEED ANALYSIS

The growth kinetics and surface structure of Y, Dy and Co silicides ar e examined using a new reflection high-energy electron diffraction (RH EED) method. We prepared epitaxial silicide films on (111) Si by (1) d eposition of metal and contact reaction (solid phase epitaxy), and (2) deposition of metal on hot substrates (reactive deposition). Subseque nt annealing at temperatures up to 600 degrees C yielded monocrystalli ne, continuous layers, whose properties were examined by means of RHEE D (in situ) and X-ray diffraction and scanning electron microscopy (ex situ). Method 2 was shown to give better results. We have measured di rectly the yttrium silicide formation temperature which can be as low as 120 degrees C for thin (60 Angstrom) metal layer deposited on (111) Si substrate. RHEED azimuthal plots of the Si layer which was grown on silicides depends strongly on the crystalline quality of the epitaxia l layers. A study of the growth of thin (10-150 Angstrom) silicon over layers on yttrium, dysprosium and cobalt silicide films epitaxially gr own on (111)Si was also made.