TEMPERATURE-DEPENDENCE OF SIGE COHERENT ISLAND FORMATION ON SI(100) -ANOMALOUS REENTRANT BEHAVIOR

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