The growth of heterojuntion bipolar transistor structures using chemical vapor deposition has been investigated. Generation of defects in selectively or nonselectively grown collector layers using arsenic as the dopant has been studied. Minimizing the defect density in SiGe base layers by optimizing the growth rate has also been investigated in detail. High resolution reciprocal lattice mapping, atomic force microscopy and secondary ion mass spectrometry have been used as the main characterization tools.