Germanium quantum dots have been grown on Si substrates at various temperatures for different durations and studied with atomic force microscopy to determine the growth conditions for the smallest and most uniform size quantum dots.Ge1−xCxquantum dots grown at varying Ge:C ratios have been characterized to study the effects of strain compensation by C. The effects of P and B doping on both Ge andGe1−xCxdots have also been investigated. The results show fewer quantum dots inGe1−xCxdue to strain compensation of Ge by C, and suggest the formation of larger dots with P doping and smaller and more uniform dots with B doping. X-ray diffraction measurements on the samples show the strain in the films, with the rocking curves changing with the ratio of C in the quantum dots. ©1997 American Institute of Physics.