Dresden 2011 – scientific programme

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HL: Fachverband Halbleiterphysik

HL 44: Poster Session I

HL 44.84: Poster

Tuesday, March 15, 2011, 18:00–21:00, P3

Reducing the dislocation density of GaAs on Si(001) using InAs quantum dots — •Martin Etter, Michael Wiesner, Wolfgang-Michael Schulz, Robert Roßbach, Michael Jetter, and Peter Michler — Institut für Halbleiteroptik und funktionelle Grenzflächen, Universität Stuttgart, Allmandring 3, 70569 Stuttgart, Germany

In order to integrate optoelectronics with standard Si microelectronics, several attempts were made to grow GaAs on Si by using buffer layers of Ge/GeSi/Si or graded GaAsP or InGaP layers or the use of strained-layer superlattices consisting of InGaAs, GaAsP or AlGaAs layers to overcome the large lattice mismatch and the different thermal expansion coefficient. A novel approach is the implementation of InAs quantum dots, which have the ability to suppress the dislocations which propagate to the GaAs surface due to their high strain field. In our work we characterize GaAs/Si-samples including different numbers of InAs quantum dot layers with a maximum GaAs layer thickness of 1 µm. Characterization is done by X-ray diffraction measurements, scanning electron microscopy (SEM), atomic force microscopy, respectively photoluminescence spectroscopy were perfomed to characterize the GaAs layers. Thereby SEM pictures show clearly the improvement of the GaAs surface compared to the other approaches. Furthermore, the influence on the quality of optoelectronic structures is shown.