Berlin 2008 – wissenschaftliches Programm
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HL: Fachverband Halbleiterphysik
HL 17: Poster I
HL 17.15: Poster
Montag, 25. Februar 2008, 16:30–19:00, Poster D
High Resolution Measurement of the Thermal Expansion Coefficient of Semiconductor Multilayer Lateral Nanostructures — •björn brüser1, ullrich pietsch1, souren grigorian1, tobias panzner1, jörg grenzer2, and ute zeimer3 — 1Festkörperphysik, Universität Siegen, Walter-Flex-Str. 3, D-57068 Siegen, Germany — 2Forschungszentrum Rossendorf e.V., P.O.Box 510119, D-013414 Dresden, Germany — 3Ferdinand-Braun Institut für Höchstfrequenztechnik, Gustav-Kirchhoff-Str. 24, D-12489 Berlin, Germany
We measured the thermal expansion coefficient of a vertically stacked multi-quantum-well structure buried under a thick GaAs top layer before and after lateral patterning of the GaAs top layer. After patterning the thermal expansion coefficient of the whole multi-quantum-well structure differs from that of the planar structure by about 20%. Based on calculations in terms of methods of finite elements the effect is explained by the influence of the strain field originating from the bottom edges of the etched nanostructure. Due to the long range nature of this strain field the strain release within the individual quantum wells changes as a function from the distance from the valley.