Porous silicon as an efficient local thermal isolation platform on the Si wafer in the temparature range 5–350k

The thermal conductivity of highly porous Si was determined in the temperature range 5-350K. It was found that its temperature dependence is monotonic in the range 20-350K, while below 20K it shows a plateau-like behavior similar to that observed in amorphous materials. The low values of the thermal conductivity of the material in the whole temperature range studied, extended also to cryogenic temperatures, make porous Si an excellent local substrate for providing efficient thermal isolation on the Si wafer for the on-chip integration of heating and cooling devices.