Initial stages of al growth from dimethylaluminum hydride on silicon

We use scanning tunneling microscopy to study the initial stages of ultrahigh-vacuum chemical vapor deposition of Al on the (Formula presented) surface from dimethylaluminum hydride (DMAH). At room temperature (300 K), the DMAH molecules adsorb intact in seven distinct configurations, which we identify as the DMAH dimer. After annealing above 525 K the molecules decompose into H, (Formula presented) and Al. By contrast, the majority of impinging DMAH molecules crack when dosed on a surface as cool as 350 K. Dosing at the industrial process temperature of 575 K produces the cleanest aluminum growth.