Silicon Germanium (SiGe) can be used to make heterojunction bipolar transistor (HBT) or CMOS devices. SiGe may be dry etched using the Inductively Coupled Plasma (ICP) and deposited using Plasma Enhanced Chemical Vapour Deposition (PECVD).
Poly SiGe possible at temperatuers >500oC
Different chemistries can be used: pure and diluted silane with GeH4.