Schottky Barrier Diodes in 90nm SiGe BiCMOS process operating near 2.0 THz cut-off frequency

High performance Schottky Barrier Diodes (SBDs) with cut-off frequency (fc) ~2.0 THz integrated into a 90nm SiGe BiCMOS technology for millimeter wave (mm-wave) applications are presented in this paper. To our knowledge, this is the highest reported fc for a SBD in a BiCMOS technology. The SBDs reported here have low reverse bias leakage with breakdown voltage of ~5V, and have been integrated in the base technology without the addition of any extra processing step. The affects of variation of critical process and device parameters - undoped silicon layer (n-epi) thickness, thermal cycle associated with deep-trench formation, cathode reach-through width, and anode area on device performance have also been investigated and are presented here.