Solid phase epitaxy of Ge films on CaF2/Si(1 1 1)

✍ Scribed by E.P. Rugeramigabo; C. Deiter; J. Wollschläger

• Publisher: Elsevier Science
• Year: 2007
• Tongue: English
• Weight: 469 KB
• Volume: 254
• Category: Article
• ISSN: 0169-4332
• DOI: 10.1016/j.apsusc.2007.07.167

✦ Synopsis

At room temperature deposited Ge films (thickness < 3 nm) homogeneously wet CaF 2 /Si(1 1 1). The films are crystalline but exhibit granular structure. The grain size decreases with increasing film thickness. The quality of the homogeneous films is improved by annealing up to 200 8C. Ge films break up into islands if higher annealing temperatures are used as demonstrated combining spot profile analysis low energy electron diffraction (SPA-LEED) with auger electron spectroscopy (AES). Annealing up to 600 8C reduces the lateral size of the Ge islands while the surface fraction covered by Ge islands is constant. The CaF 2 film is decomposed if higher annealing temperatures are used. This effect is probably due to the formation of GeF x complexes which desorb at these temperatures.