Reduction in misfit dislocation density by the selective growth of Si1−xGex/Si in small areas

Abstract

Si_1−xGe_x and Si layers have been grown selectively in the exposed Si regions on oxide‐patterned 〈100〉 oriented Si wafers using the chemical vapor deposition technique limited reaction processing. Misfit dislocation spacings at the heterointerface were measured using plan‐view transmission electron microscopy in conjunction with a large‐area thinning technique which allows for examination of 100–150 μm diameter areas. The dislocation density is reduced by at least a factor of 20 for small areas (lateral dimensions: tens of microns) bounded by oxide isolation when compared to adjacent large areas (millimeters) which are uninterrupted by the patterned oxide. The ability to selectively grow Si_1−xGe_x on patterned wafers and the area‐dependent reduction in dislocation density in as‐grown films may be important considerations for future device applications using Si_1−xGe_x strained layers.