Adsorption of SiH or Si H on PrSi 100/ at room temperatures

Effects of predeposition of phosphorus on room temperature adsorption of SiH4or Si2H6 on Si 100.surfaces have been investigated by H2-temperature-programmed-desorption measurements. As a result, it was clarified that the amount of adsorbed SiH4 or Si2H6 molecules after saturation, as measured from the hydrogen coverage u H sat., decreases from that on a bare-Si surface, satisfying the relation uH sat.quPs1, with u P the predeposited phosphorus coverage. This relation indicates that neither SiH4 nor Si2H6 chemisorbs at phosphorus sites at room temperatures. For initial adsorptions, by contrast, the adsorption of SiH4 or Si2H6 were less affected, for which migration of physisorbed molecules from P-sites toward bare-Si sites is suggested. q1998 Elsevier Science B.V. All rights reserved.