Characterization of Polysilicon Microstructures to Estimate Local Temperature on CMOS Chips

The measurement of local temperature on application specific integrated circuits (ASICs) can be used to determine the reliability of electronics implemented on the chip. For this reason, we propose a simple method to monitor the temperature on CMOS by using polysilicon microstructures realized in AMS 350 nm technology. The surrounding temperature on a CMOS chip was extracted from four-probe resistance measurement of two polysilicon microstructures fabricated during the IC manufacturing process. Electrical characterization of these microstructures was performed within 25 to 400 °C for using them as on-chip temperature sensors. The sensors were tested with in-built CMOS microheaters as heat source. Results show that an IC temperature ranging from room-temperature to 200 °C can be estimated with a deviation below 2 °C between the two sensors, while the deviation increases with higher temperature. Overall, the proposed method is simple and requires minimal measurement setup to monitor the temperature on ICs.