BiCMOS

Bipolar CMOS (BiCMOS) is a

metal–oxide–semiconductor) logic gate, into a single integrated circuit.^[1]^[2] In more recent times the bipolar processes have been extended to include high mobility devices using silicon–germanium

junctions.

Bipolar

amplifiers including low noise radio frequency (RF) amplifiers that only use a few active devices, while CMOS technology offers high input impedance and is excellent for constructing large numbers of low-power logic gates. In a BiCMOS process the doping profile and other process features may be tilted to favour either the CMOS or the bipolar devices. For example GlobalFoundries offer a basic 180 nm BiCMOS7WL process and several other BiCMOS processes optimized in various ways.^[3] These processes also include steps for the deposition of precision resistors, and high Q RF inductors and capacitors

on-chip, which are not needed in a "pure" CMOS logic design.

BiCMOS is aimed at

bandgap-based references and low-noise circuits.^{[citation needed}

]

The

Pentium, Pentium Pro, and SuperSPARC microprocessors

also use BiCMOS.

Disadvantages

Some of the advantages of CMOS fabrication, for example very low cost in mass production, do not transfer directly to BiCMOS fabrication. An inherent difficulty arises from the fact that optimizing both the BJT and MOS components of the process is impossible without adding many extra fabrication steps and consequently increased process cost and reduced yield. Finally, in the area of high performance logic, BiCMOS may never offer as low a power consumption as a foundry process optimized for CMOS alone, due to the potential for higher standby leakage current.

References

^ Puchner, H. (1996). "5.2 BiCMOS Process Technology". Advanced Process Modeling for VLSI Technology (PhD). Institut für Mikroelektronik, Technischen Universität Wien. TUW-101186.
^ Puchner 1996, 5.2.1 BiCMOS Process Flow
^ https://www.globalfoundries.com/sites/default/files/sige_hp_pb_2020-0212web.pdf ^{[bare URL PDF]}

[1] Puchner, H. (1996). "5.2 BiCMOS Process Technology". Advanced Process Modeling for VLSI Technology (PhD). Institut für Mikroelektronik, Technischen Universität Wien. TUW-101186.

[2] Puchner 1996, 5.2.1 BiCMOS Process Flow

[3] ttps://www.globalfoundries.com/sites/default/files/sige_hp_pb_2020-0212web.pdf ^{[bare URL PDF]}

[1]

[2]

[3]

v t e Logic families
MOS technology	PMOS logic NMOS logic Depletion-load NMOS logic (including HMOS) Complementary MOS (CMOS) Pass transistor logic (PTL) Bipolar–CMOS (BiCMOS)
Other technologies	Diode logic Diode–transistor logic (DTL) Open collector (OC) Direct-coupled transistor logic (DCTL) Emitter-coupled logic (ECL) Gunning transceiver logic (GTL) Integrated injection logic (I²L) Resistor–transistor logic (RTL) Transistor–transistor logic (TTL) Current mode logic / Source-coupled logic (CML/SCL)
Types	Static Dynamic Domino logic Four-phase logic