SHORT-TIME-SCALE THERMAL MAPPING OF MICRODEVICES USING A SCANNING THERMOREFLECTANCE TECHNIQUE

The performance and reliability of microdevices can be strongly influe nced by the peak temperature rise and spatial temperature distribution during brief electrical overstress (EOS) phenomena, which can occur a t sub-microsecond time scales. The present study investigates short-ti me-scale laser reflectance thermometry of microdevices by examining th e impact of passivation overlayers on the thermoreflectance signal and by demonstrating a calibration method suitable for metallization. Thi s manuscript also describes a scanning laser thermometry facility that captures temperature fields in microdevices with 10 ns temporal resol ution and 1 mu m spatial resolution. The facility combines scanning la ser optics with electrical stressing capability to allow simultaneous interrogation of the thermal and electrical behavior of devices. Data show the transient temperature distribution along the drift region of silicon-on-insulator (SOI) power transistors and along metal interconn ects subjected to brief electrical stresses. The theory and experiment al capability developed in this study are useful for studying short-ti me-scale thermal phenomena in microdevices and verifying models employ ed for their simulation.