Comparison between bulk and floating body partially depleted SOI nMOSFETS for high frequency analog applications operating from 300 K down to 95 K

Abstract

A comparison between deep-submicrometer bulk and floating-body partially depleted (PD) SOI nMOSFET operation for high frequency analog applications is performed from room temperature down to 95 K. The transistor intrinsic gain, cutoff frequency and bias current are used as figures of merit for this comparison. It is demonstrated that bulk transistors can have larger intrinsic gain at any temperature of operation due to their larger Early voltage. On the other hand, the cutoff frequency is improved in PD SOI without halo due to the larger carrier mobility and velocity saturation. Also PD SOI without halo reaches a frequency of 13 GHz at 95 K, whereas bulk and PD SOI with halo reach 11 GHz for the same load capacitance of 100 fF.