INITIAL-STAGE GROWTH OF IN AND AL ON A SINGLE-DOMAIN SI(001)2X1 SURFACE

Initial stage growth of In and Al on a wide-terrace single-domain Si(001)2 X 1 surface has been studied by low-energy electron diffraction (LEED) and X-ray photoelectron spectroscopy. Several submonolayer phases that were not reported on double-domain Si(001)2 X 1 substrates are observed, in addition to those already reported. The resulting sequences of two-dimensional (2D) phases for In and Al coverages of less than or equal to 0.5 ML can be interpreted based on an order-disorder transition of arrays of 1D metal-dimer chains. The results show close resemblance to the initial growth of Ga on Si(001) and thus indicate that there is a general mode of growth for the Group-III metals on a Si(001)2 X 1 surface below 0.5 ML. Growth for coverages greater than 0.5 ML and the onset of 3D growth are also discussed.