Shot-noise-induced excess low-frequency noise in floating-body partially depleted SOI MOSFET's

Floating-body partially depleted (PD) SOI MOSFET's exhibit excess low-frequency noise. For the first time, the origin of the excess noise is identified to be the shot noise associated with impact ionization current and body-source diode current. The shot noise, normally negligible as compared with flicker noise, is amplified in the device through the floating-body effect (FBE). A physically-based noise model is proposed which predicts that the excess low-frequency noise shows a Lorentzian-like spectrum as verified by experimental data. The physical explanation is further supported by the coincidence of the characteristic frequency in noise spectrum and ac output impedance of the device.