IOTA: Towards an integrated on-chip thermocouple array

We present the design concept of a bimetallic thermocouple array-based temperature sensor to monitor thermal behavior of integrated circuits. Our proposed design is able to provide fine-grain thermal characterization. Such a sensor array that is capable of monitoring a large area accurately at a fine granularity is essential to perform reliable and effective dynamic thermal management for high performance chips. Since our proposed thermocouple array-based sensor uses only metals, the resulting sensor design occupies minimal area on the silicon layer. Furthermore, we show that such a metal-based design is advantageous in mitigating process variations. The working principle of the proposed thermocouple array is demonstrated with a bimetallic macroscopic prototype. Our thermocouple prototype tracks the temperature variation from 20°C to 160°C to within less than 1°C. Furthermore, our analysis indicates that the sensor array is robust against process variations to a thermal accuracy of less than 1°C.