SiGe is having a major impact in device electronics. The most mature application is the SiGe BiCMOS technology which is in production throughout the world. The areas of most rapid growth are in CMOS where SiGe is being considered for a wide variety of elements including raised S/D, poly-SiGe Gates, in buffer layers to create a tensile strained Si layer, and as the conducting channel in MODFETs. (C) 2003 Published by Elsevier B.V.