University Grenoble Alpes, Grenoble, France, CEA, LETI, Minatec Campus, Grenoble, France, Applied Materials Inc., Sunnyvale, CA, United States

We have studied in the 300-350°C temperature range, the 100 Torr epitaxy of heavily in-situ phosphorous doped Ge and high Sn content GeSn alloys in a 200 mm industrial Reduced Pressure - Chemical Vapor Deposition tool. We have first of all quantified the impact of the phosphine (PH3) flow on the structural and electrical properties of Ge:P layers. To that end, we have used a dedicated low temperature Ge precursor, digermane (Ge2H6), in order to promote P incorporation. We have reached very high atomic and electrically active P concentrations, at most 5 × 1020 cm-3 and 7.5 × 1019 cm-3, respectively. We have then evaluated the impact of the Ge2H6 and SnCl4 flows on the GeSn growth kinetics at 325°C, 100 Torr. As expected, the GeSn growth rate increases almost linearly with the Sn concentration, from 5 up to 21 nm.min-1. The Sn atoms seem to catalyze H desorption from the surface, resulting in higher GeSn growth rates, then. Finally, we have studied the impact of temperature, in the 300-350°C range, on the GeSn growth kinetics. The GeSn growth rate exponentially increases with the temperature, from 15 up to 32 nm.min-1. The associated activation energy is low, e.g. Ea = 11 kcal.mol-1. Really high Sn concentrations (at most 15%) were obtained in smooth, single crystalline layers. © 2016 The Electrochemical Society. All rights reserved.

Digermane, GeSn growth kinetics, High Sn content GeSn alloys, In-situ phosphorous doping of germanium, Phosphine, Reduced-pressure chemical vapor deposition, Tin tetrachloride, Very low temperature epitaxy

Activation energy, Chemical vapor deposition, Deposition, Epitaxial growth, Germanium, Growth kinetics, Growth rate, Kinetics, Phosphorus, Phosphorus compounds, Temperature, Tin, Vapor deposition, Digermane, GeSn alloys, Phosphine, Phosphorous doping, Reduced pressure chemical vapor deposition, Very low temperatures, Tin alloys