HBT device robustness against process variations in millimeter-wave BiCMOS technology

Device electrical parameters and performance after optimization are often presented in literature. However, publications rarely address device stability versus process dispersion. Such a study was performed on the high-speed Si/SiGe heterojunction bipolar transistor (HS HBT) from a millimeter-wave BiCMOS technology. The process parameters were intentionally de-centered during the fabrication to monitor device electrical response and evaluate potential weaknesses or instability. This paper presents the results of this work and demonstrates the device robustness.