Ring oscillator

Electrical engineering

Physics

Fabrication

Pathology

Nanotechnology

Transistor

Heterojunction bipolar transistor

Dopant

Dopant Activation

Silicon-germanium

CMOS

Millisecond

Heterojunction

Astronomy

Epitaxy

Engineering

Voltage

Composite material

Bipolar junction transistor

Materials science

Alternative medicine

Annealing (glass)

Disilane

Layer (electronics)

Computer science

Silicon

BiCMOS

Scalability

Optoelectronics

Doping

Medicine

Database

Semiconductor Science and Technology

This paper addresses fabrication aspects of SiGe heterojunction bipolar transistors which record high-speed performance. We previously reported fT values of 505 GHz, fMAX values of 720 GHz, and ring oscillator gate delays of 1.34 ps for these transistors. The impact of critical process steps on radio frequency performance is discussed. This includes millisecond annealing for enhanced dopant activation and optimization of the epitaxial growth process of the base layer. It is demonstrated that the use of a disilane precursor instead of silane can result in reduced base resistance and favorable device scalability.

High-performance SiGe HBTs for next generation BiCMOS technology