High electron mobilities in surfactant-grown Germanium on Silicon substrates
In: Japanese Journal of Applied Physics, Jg. 36 (1997), S. 1082-1085
Zeitschriftenaufsatz / Fach: Physik
Fakultät für Physik » Experimentalphysik
We present the first investigation of the electrical properties of relaxed Ge layers grown on Si(111) substrates by surfactant-mediated epitaxy with Sb. Electron Hall mobilities and carrier concentrations of 1 µ m thick epitaxial Ge layers grown on p-type Si-substrates at temperatures between 640° C and 720° C were determined at 300 K and 77 K. The highest electron mobilities, 3100 cm2/Vs and 12300 cm2/Vs, at 300 K and 77 K, were observed in the 720° C sample. At 300 K an electron concentration of only 1.1×1016 cm-3 was measured suggesting a substantially lower incorporation of the surfactant Sb compared to earlier publications. The low Sb doping was independently supported by secondary ion mass spectroscopy (SIMS).