Influence of As on the formation of mask-edge defects during stressed solid phase epitaxy in patterned Si wafers

The influence of As on the evolution of mask-edge defects during stressed solid phase epitaxy of two-dimensional Si+ pre-amorphized regions in patterned Si wafers was examined. Mask-edge defects ∼60 nm deep formed at 525 °C for As+ implant energies of 7.5-50 keV with peak As concentration of ∼5.0× 1020 cm-3. Defect formation was attributed to an As-enhanced [110] regrowth rate relative to the [001] regrowth rate creating an amorphous/crystalline interface geometry favorable for defect formation. The similarity of mask-edge defect depths with As+ implant energy was attributed to surface retardation of [110] regrowth in shallow implants and enhanced [001] regrowth in deeper implants. Results indicate stress effects on regrowth rates are small compared to dopant effects.