Temperature-Dependent Thermal Capacitance Characterization for SOI-MOSFETs

Thermal capacitances are required to describe the fast dynamic thermal behavior in the silicon-on-insulator (SOI) devices. This article presents a physical model based on the ac technique, together with the characteristic thermal frequency determination through the frequency response of the output conductance, for calculating the thermal capacitance of single-finger and multi-finger SOI-MOSFETs. The model accounts for the total gate width and substrate temperature, making evident the augmented thermal coupling when multi-fingers are used. The thermal capacitances and the corresponding time constants, extracted from a variety of gate widths and number of fingers, are correctly predicted up to a substrate temperature of 150 °C.