Multilayer adsorption of Li on Si(100)2 x 1 surfaces studied with metastable de-excitation spectroscopy and thermal desorption spectroscopy

The multilayer adsorption of Li on Ta foil and Li on Si(100)2 x 1 surfaces is discussed, based on the experimental data of thermal desorption spectros copy and metastable de-excitation spectroscopy. Taking the former results o f Ba adsorption on Si(100)2 x 1 into account, it can be understood that abo ve about 1 ML of Li coverage, intermixing or silicide formation starts at r oom temperature. However, the outermost surface adsorbed by more than 3.3 M L is like pure Li. When this sample (with an adsorption of more than 3.3 ML of Li and with a surface like that of pure Li) is heated to 250 degrees C, its outermost surface is changed into silicide. (C) 1999 Elsevier Science B.V. All rights reserved.