Mechanical Properties of the GaAs/Si [001] Interface by X-rays Hybrid Multiple Diffraction

Abstract

ABSTRACTIn this work, the directions of the secondary beams which are scattered by each mosaic block within an epitaxial layer allow to explain the position and profile of the LS hybrid multiple diffraction peak in the substrate Renninger Scan (RS). Furthermore, by choosing a secondary beam diffracted almost parallel to the interface, the LS peak is able to provide information even for thin (500Å) layers. The position of the LS peak in the substrate RS of the GaAs layers grown by VCE on Si(001) provides the a║ values necessary to analize the layer stress state. As an external bending moment is applied on the sample to compensate the stress steming from the difference in thermal expansion coefficients a split of both epilayer and buffer layer LS peaks can be observed. This split also indicates the degree of cohesion between these two layers.