Development of IC-based temperature monitor with spaciotemporal resolution

Abstract

Excessive self-heating in integrated circuits (ICs) is a major barrier to performance and reliability within the semiconductor industry and necessitates innovation in thermal management. Effective thermal management is critical, but experimental evaluation of cooling solutions, especially hotspot mitigation, are limited due to challenges in acquiring accurate spatiotemporal temperature data. This work presents an in-line spatial and temporal temperature mapping system designed to interface directly between an IC and its cooling device, consisting of a dense array of 64 aluminum resistance temperature detectors (RTDs) sensors integrated within an automated measurement system. The RTD array was successfully fabricated using a single-layer lift-off process on an oxide-wafer substrate. An automated measurement system utilizing GPIB instruments and multiplexing for four-point measurements was developed for real-time data acquisition and calibration. Calibration performed on 28 functional sensors demonstrated high linearity with an average measured temperature coefficient of resistance (TCR) of 1730 ppm/ºC. In-situ measurements successfully demonstrated the capability to resolve ambient temperature, thermal transients, and non-uniform thermal gradients, providing necessary experimental data for thermal characterization. During non-uniform heating, spatial temperature gradients could be resolved within 0.1 °𝐶. This work validates the design, fabrication, and characterization of an aluminum RTD sensor array system for in-situ spatiotemporal temperature mapping, contributing to the experimental evaluation of IC thermal management solutions. Author Keywords: Temperature sensor array, integrated circuit, resistance temperature detector (RTD), integrated circuit (IC), automated measurement system, thermal analysis, hot spots