Under-FET Thermal Sensor Enabling Smart Full-Chip Run-Time Thermal Management

This article reports design, fabrication and analysis of a novel under-transistor (under-FET) in-hole thermal sensor diode structure. Being able to accurately monitor self-heating of individual transistor in-operando, the under-FET temperature sensor enables smart full-chip run-time thermal management with spatial resolution down to single transistor level. The in-hole thermal sensors were fabricated in a CMOS process and validated in measurements. The new chip level thermal management technique was demonstrated using a prototype power amplifier (PA) IC designed in a foundry 40nm CMOS. It opens a door for self-learning based full-chip real-time intelligent thermal management for future ICs.