Localized heating and thermal characterization of high electrical resistivity silicon-on-insulator sensors using nematic liquid crystals

We present a method for localized heating of media at the surface of silicon-on-insulator field-effect sensors via application of an ac voltage across the channel and the substrate and compare this technique with standard Joule heating via the application of dc voltage across the source and drain. Using liquid crystals as the medium to enable direct temperature characterization, our results show that under comparable bias conditions, heating of the medium using an alternating field results in a greater increase in temperature with a higher spatial resolution. These features are very attractive as devices are scaled to the nanoscale dimensions. (C) 2008 American Institute of Physics.