Available online 16 January 2013
Publication year: 2013
Source:Journal of Crystal Growth
We fabricate uniaxially strained SiGe buffer layers by the selective ion implantation technique, where laterally selective ion implantation with a stripe pattern is performed into a Si substrate, followed by SiGe overgrowth in the whole region. Large strain relaxation of SiGe occurs only in the ion-implanted area. This relaxed SiGe provides shear stress to the neighboring strained SiGe in the unimplanted area, leading to the uniaxial strain relaxation. The surface observation exhibits array of one direction steps which corresponds to misfit dislocations. The relaxation ratios estimated from the dislocation periodicities agree very well with those obtained from x-ray diffraction, indicating that the uniaxial strain is induced by the plastic deformation via dislocation generation. This fact means that the induced uniaxial strain is very stable, and hence, the SiGe layer can be used as a promising template for uniaxially strained Si/Ge channels grown on it.
► Uniaxially strained SiGe layers are fabricated by the selective ion implantation technique. ► The origin of the uniaxial strain is plastic deformation via directional dislocation generation. ► Observation of one directional surface steps indicate the one directional misfit dislocations. ► This technique opens the way to realize high mobility Si/Ge channels with uniaxial strain.
Publication year: 2013
Source:Journal of Crystal Growth