Channel soft breakdown enhanced excess low-frequency noise in ultra-thin gate oxide PD analog SOI devices [MOSFETs]

The impact of soft breakdown (SBD) location on drain current noise in partially depleted SOI MOSFETs with ultra-thin oxide (1.6 nm) is investigated. In a channel breakdown device, a noise overshoot phenomenon is observed in the ohmic regime. The peak amplitude can be about one order of magnitude higher than the background 1/f noise. In addition, it is shown that the corresponding spectrum has a Lorentzian shape. The origin of this excess noise is believed to be related to SBD enhanced electron valance-band tunneling induced floating body effect. The findings indicate that channel SBD enhanced drain current noise can be a reliability issue in PD analog SOI CMOS circuit.