Ultra-low-power thermal sensor with silicon-on-insulator (SOI) structure for high-temperature applications

In this work, thermal resistors based on a simple rectangular structure are fabricated on three kinds of substrates thin-film (0.1 /spl mu/m) silicon-on-insulator (SOI), thick-film (10 /spl mu/m) SOI and bulk Si, and their characteristics are investigated. Measurements verify that SOI can indeed have additional freedom for increasing the maximum operating temperature (T/sub max/). More importantly, the thin-film SOI thermal resistor not only achieves a T/sub max/ as high as 420/spl deg/C, but also a low operating current of 1 /spl mu/A, which is about 1,000 times smaller than that of the thick-film SOI counterpart for the same T/sub max/. In conclusion, silicon resistor on SOI is a promising low-cost thermal sensor for a broad scope of low-power high-temperature applications.