The high carrier mobility in SiGe heterostructure layers enable an increased RF performance of field-effect transistors (FETs) compared with standard metal-oxide semiconductor (MOS) devices. Both p- and n-type transistors require relaxed SiGe buffer layers as artificial substrates. In this paper, the influence of molecular beam epitaxy (MBE) growth parameters on the surface morphology and crystal quality of strain relieved SiGe buffers on Si is discussed. The surface roughness of graded and constant composition buffers grown under different conditions is related to electrical results.