Reduction of Low Frequency Noise of Buried Channel PMOSFETs With Retrograde Counter Doping Profiles

The impacts of retrograde counter doping (RCD) profiles on low frequency noise (LFN) of buried channel (BC) PMOSFETs were investigated. RCD profiles were formed using heavy ion implantation. The RCD profile reduced LFN by more than 50%. The origin of LFN reduction in the RCD device was investigated using TCAD simulation. It was found that both RCD profile itself and the polarity of Si surface contributed to the deeper channel position and larger energy barrier between Si surface and channel position.