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

Abstract

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. © 2008 American Institute of Physics.