Influence of growth temperature on interdiffusion in uncapped SiGe-islands on Si(001) determined by anomalous x-ray diffraction and reciprocal space mapping

The influence of growth temperature in the regime of dome formation in Stranski-Krastanow growth is studied systematically on a series of Ge on Si(001) samples. A combination of complementary x-ray scattering methods is applied, in order to resolve the island size, their strain state, and the composition distribution. The composition is determined using anomalous x-ray diffraction at high momentum transfer in combination with atomic force microscopy and from x-ray reciprocal space mapping. For growth temperatures between 620 and 840 degreesC, the maximum Ge content of the as-grown islands decreases from about 70 to about 22%. The results are corroborated by a selective etching study of the Ge islands.