Details

Autor(en) / Beteiligte

• Yurasov, D. V.
• Antonov, A. V.
• Drozdov, M. N.
• Schmagin, V. B.
• Spirin, K. E.
• Novikov, A. V.

Titel

Antimony segregation in Ge and formation of n-type selectively doped Ge films in molecular beam epitaxy

Ist Teil von

• Journal of applied physics, 2015-10, Vol.118 (14)

Ort / Verlag

Melville: American Institute of Physics

Erscheinungsjahr

2015

Quelle

American Institute of Physics (AIP) Journals

Beschreibungen/Notizen

• Antimony segregation in Ge(001) films grown by molecular beam epitaxy was studied. A quantitative dependence of the Sb segregation ratio in Ge on growth temperature was revealed experimentally and modeled theoretically taking into account both the terrace-mediated and step-edge-mediated segregation mechanisms. A nearly 5-orders-of-magnitude increase in the Sb segregation ratio in a relatively small temperature range of 180–350 °C was obtained, which allowed to form Ge:Sb doped layers with abrupt boundaries and high crystalline quality using the temperature switching method that was proposed earlier for Si-based structures. This technique was employed for fabrication of different kinds of n-type Ge structures which can be useful for practical applications like heavily doped n+-Ge films or δ-doped layers. Estimation of the doping profiles sharpness yielded the values of 2–5 nm per decade for the concentration gradient at the leading edge and 2–3 nm for the full-width-half-maximum of the Ge:Sb δ-layers. Electrical characterization of grown Ge:Sb structures revealed nearly full electrical activation of Sb atoms and the two-dimensional nature of charge carrier transport in δ-layers.