Germanium-silicon epitaxial growth by chemical vapor deposition (CVD) has proven to be suitable for growth of many heterojunction devices. We report here on recent work with one CVD technique (UHV/CVD, or ultrahigh vacuum chemical vapor deposition) which is capable of multiwafer deposition of advanced device structures. First, the physics and chemistry of the growth process are outlined and the factors which influence layer uniformity and heterojunction abruptness are discussed. We then present recent results from the characterization of doped multiple quantum well structures suitable for far-infrared detectors.