Transmission electron microscopy study of rapid thermally annealed Pd/Ge contacts on In0.53Ga0.47As
P. Ressel1, W. Österle2, I. Urban2, I. Dörfel2, A. Klein1, K. Vogel1 and H. Kräutle3
Published in:
J. Appl. Phys., vol. 80, no. 7, pp. 3910-3914 (1996).
Abstract:
Phase formation in rapid thermally annealed Pd/Ge contacts on In0.53Ga0.47As has been investigated by means of cross-sectional transmission electron microscopy, convergent-beam electron diffraction, and energy-dispersive x-ray analysis.Solid-phase regrowth is observed to occur similarly as in Pd/Ge contacts on GaAs or InP. The reaction starts at low temperatures with the formation of an amorphous Pd-In-Ga-As layer, which crystallizes at elevated temperatures yielding hexagonal Pd4In0.53Ga0.47As being first described in this work. At temperatures ≥250°C, this phase decomposes due to epitaxial solid-phase regrowth of In0.53Ga0.47As and formation of Pd-Ge phases. The stable composition is reached at temperatures ≥350°C with excess Ge diffused through top Pd-Ge to the contact interface and growing epitaxially on the semiconductor.
1 Ferdinand-Braun-Institut für Höchstfrequenztechnik, Rudower Chaussee 5, D-12489 Berlin, Germany
2 Bundesanstalt für Materialforschung und ‐prüfung, Unter den Eichen 87, D‐12200 Berlin, Germany
3 Deutsche Telekom AG, Tz Am Kavalleriesand 3, D‐64295 Darmstadt, Germany
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