SiGe

SiGe stands for Silicon-Germanium heterojunction bipolar transistor and is an integrated circuit (IC) manufacturing technology. This relatively new technology offers interesting opportunities in mixed-signal circuit and analog circuit IC design and manufacture. Some of the key points of SiGe include:

• SiGe is manufactured on traditional silicon wafers and largely uses conventional (and highly amortized capital cost ) silicon process fabs and technologies given its economic price/performance levels closer to traditional silicon CMOS or bipolar transistor manufacturing versus other heterojunction technologies in III-V semiconductor like GaAs or Gallium Arsenide.

• SiGe allows both state of the art CMOS devices and gates to be combined with ultra high performance heterojunction bipolar transistor devices making it optimal for mixed-signal circuits.

• Heterojunction bipolar transistor have significantly higher forward gain and lower reverse gain which translates into far better low current and high frequency performance than typically available from homojunction or traditional bipolar transistors

• Being a heterojunction technology, the opportunity for band-gap tuning exists which has normally been available only to so-called III-V semiconductors.

The major players in SiGe foundry services are IBM, TSMC, Freescale nee Motorola Semiconductor, Sony, Atmel, Chartered Semiconductor , Micrel and Conexant