SOI thermal impedance extraction methodology and its significance for circuit simulation

The buried-oxide in SOI MOSFET inhibits heat dissipation in the Si film and leads to increase in transistor temperature. This paper reports a simple and accurate characterization method for the self-heating effect (SHE) in SOI MOSFET. The ac output conductance at a chosen bias point is measured at several frequencies to determine the thermal resistance (R-th) and thermal capacitance (C-th) associated with the SOI device. This methodology is important to remove the misleadingly large self-heating effect from the de T-V data in device modeling. Not correcting for SHE mag lead to significant error in circuit simulation. After SHE is accounted for, the frequency-dependent SHE may be disabled in circuit simulation without sacrificing the accuracy, thus providing faster circuit simulation for high-frequency circuits.