Influence of back-end architectures on the performance of RF CMOS VCOs

Voltage controlled oscillators (VCOs) with low phase noise are one of the most difficult RF building-blocks to integrate on a (Bi)CMOS chip. Their performance is limited by the low quality factors of the integrated inductors. This paper studies the influence of advanced back-end (BEOL) silicon CMOS architectures and on-chip wafer postprocessing on the performance of a 2 GHz VCO. Simulation results show that the on-chip post-processed passives are a competitor to off-chip passives to make RF VCOs.