Facet investigation in selective epitaxial growth of Si and SiGe on (001) Si for optoelectronic devices

The facet evolution and growth rate of Si on ${hkl}$ facets were investigated in the temperature range 700–850 $°$C using multilayer structures with thick Si and very thin SiGe markers prepared by selective epitaxial growth using low pressure chemical vapor deposition. The most stable facet, observed at all temperatures, is the high index plane {113}. It is the dominant facet up to the top of all mesas $(∼1$μm thick). Even at the corners of square dots steep {113} facets developed [angle of $72°$ with the (001) plane]. Several facets reported here are observed for the first time. In the $〈110〉$ zone it is the {119} facet, while in the $〈100〉$ zone two facets with Miller indices $h≠k≠l≠h$⁠, the {018} and {0 1 12}, are found. The measured growth rate relationship is $R111<R110<R113<R018<R119<R0112<R001.$ The activation energy of the growth rate $Rhkl$ on the facet is roughly equal to the activation energy for growth on (001), which implies that the same step involved in the deposition limits the growth rate on (001) and on {hkl} surfaces (at least for the {111} and {113} facets). Only the {113} and {110} facets extend and grow from the beginning of the epitaxy up to the top. The first demonstration of photoluminescence from SiGe quantum wells grown on {113} Si is given.