Effects of patterned, stressed SiN overlayers on Si solid phase epitaxy

Striking nonuniformities are observed in the solid phase epitaxy ( SPE ) of blanket amorphized Si layers recrystallized in the presence of stress distributions induced by a patterned SiN overlayer. Measurements conducted for a range of SiN feature sizes and intrinsic stress values allowed us to isolate the effects of stress on the crystallization front. It is concluded that SiN- induced variations in SPE rates arise both from line- edge stresses, which scale with feature stress and increase SPE rates where the hydrostatic stress is compressive, and a SiN body effect, which suppresses SPE rates under the SiN features, independent of SiN stress state. (C) 2008 American Institute of Physics.