X-ray interface characterization of Ge δ layers on Si (001)

✍ Scribed by D. Bahr; J. Falta; G. Materlik; B.H. Müller; M. Horn-von Hoegen

• Publisher: Elsevier Science
• Year: 1996
• Tongue: English
• Weight: 387 KB
• Volume: 221
• Category: Article
• ISSN: 0921-4526
• DOI: 10.1016/0921-4526(95)00911-6

✦ Synopsis

Detailed characterization of extremely thin buried Ge films of monolayer thickness (6 layers) was performed by combination of grazing incidence X-ray reflectivity, crystal truncation rods, and X-ray standing waves. Grazing incidence reflectivity and crystal truncation rods are used to determine the average layer thicknesses and interface roughnesses as well as the stoichiometry of the layers. X-ray standing wave measurements give an independent measure of the epitaxial quality of the Ge film. Ge 6 layers on Si(0 0 l ) were grown by molecular beam epitaxy (MBE) at 350 °C with coverage ranging from 1 to 6 ML. We find strong segregation of the first deposited Ge monolayer with subsequent Si deposition. Upon deposition of more Ge, additional Ge forms a Ge film at the Si/Ge interface. The thickness of this film is limited by Ge island formation for Ge coverage exceeding 3-4 ML.