EPITAXIAL-GROWTH OF AL ON SI(100) AND SI(111) BY EVAPORATION IN UHV

Growth of Al on Si(100) and Si(111) in uhv was investigated using in situ RHEED, LEED and AES and ex situ TEM. The substrates were kept at room temperature during growth. Al was found to grow epitaxially on Si(100) 2 × 1 with the orientation relationship Al(110)|Si(100). TEM and RHEED showed that the Al layer has two types of (110) oriented domains that were 90° rotated with respect to each other in accordance with the following relations Al[001]|Si[011] or Si[011]. The decay in the Si AES peak-to-peak intensity indicated a deviation from a layer-by-layer growth at an Al coverage of ∼4 ML. We suggest that the Al overlayer replicates the double domain Si(100) 2 × 1 surface and thus can map the step structure on the Si surface. On Si(111) Al grew epitaxially following the relation: Al(111)|Si(111), Si[110]|Al[110] for most of the film, while a few grains grew according to the relation Al(100)|Si(111) with Al[011]|Si[110]. © 1990.