Published online by Cambridge University Press: 26 February 2011
Cross-section transmission electron microscopy (X-TEM) has been used to illustrate the amornhous/ crystalline (a/c) micromorphology dependence of various low dose Ge+ preamorphizatlon implants in Si. Ge+ Implants were done at room _emperature at energies of 150 and 300 keV in the dose range of 1 to 9E14 cm−2. These implants result in the formation of either a buried or a continuous amorphous layer, with rough a/c interfaces. Nucleation of spanning “hairpin” dislocations during subsequent solid phase epltaxy (SPE) regrowth is known to be related to rough a/c interface morphology. Very low temperature anneals (VLTA),less than 500°C where the rate of SPE is minimal, were utilized to sharpen rough a/c interfaces prior to subsequent SPE regrowth. Sharpening of rough a/c interfaces is shown to result from an unexpected reverse crystalline to amorphous phase transition. This reverse phase transition results in the dissolution of detached microcrystallltes located within the amorphous layer near the a/c interface. Utilization of VLTA interfacial smoothing prior to SPE regrowth therfore, results in the reduction of residual spanning “hairpin” dislocations along with homogenization of the amorphous material.