Successful Selective Epitaxial Si[sub 1−x]Ge[sub x] Deposition Process for HBT-BiCMOS and High Mobility Heterojunction pMOS Applications

heterostructures are useful for numerous device applications where device performance is improved by band offsets and/or increased carrier mobility. The use of selective epitaxial growth for the implementation of has some advantages compared to a nonselective growth process. However, some issues such as thickness nonuniformity (microloading on a micrometer scale and gas depletion on a wafer scale) and facet formation must be solved. In this paper, we give a detailed overview of our selective growth process in a standard production-oriented chemical vapor deposition system for Ge contents between 0 and 32%. Our process allows layer deposition with no pattern dependence of the growth rate and Ge content (no microloading) and with a wafer scale layer nonuniformity that is better than the accuracy of the measurement techniques Facet formation was avoided by choosing the correct growth conditions and by preventing lateral growth over the mask material. Selective epitaxial layers did not show a degradation of photoluminescence characteristics. The layer quality is further demonstrated by the performance of heterojunction bipolar transistors (0.35 and 0.25 μm technology), and p-type heterojunction metal oxide semiconductor devices (effective gate length down to 70 nm).