Compact modeling of the self heating effect in 120 nm multifinger body-contacted SOI MOSFET for RF circuits

With enhancement in the cut-off frequency, CMOS technologies become good candidates for RF applications. Moreover, SOI technologies allow to increase circuit speed, electrical device insulation, suppression of latch up, etc. However, buried oxide increases thermal insulation of the channel region. A consequence is the self heating effect (SHE), which reduce mobility and saturation velocity. This work shows that these degradations are less significant for RF multifinger structures (low thermal resistance) than for a single transistor. To represent this effect, a compact model of thermal resistance with geometrical dependencies is given. This model can be added in BSIM SOI for instance.