Temperature Dependence of SiGe Coherent Island Formation on Si(100): Anomalous Reentrant Behavior

Studies of the temperature dependence (450--800^∘C) of coherent island formation in SiGe alloys (nominal composition ~25%Ge) on Si(100) reveal an anomalous islanding behavior. Three dimensional island formation appears to be suppressed at temperatures below 450^∘C, and again in a narrow temperature window near ~600^∘C. At all other temperatures, faceted 3D islands are observed. The anomalous effect at intermediate temperatures is qualitatively explained on the basis of a relative reduction in the driving force due to temperature dependent behavior of Ge segregation and interdiffusion.