ESD Detection Circuit and Associated Metal Fuse Investigations in CMOS Processes

A circuit to detect and record the occurrence of an electrostatic discharge (ESD) event on a powered or unpowered integrated-circuit (IC) chip is presented. The ESD detection circuit uses metal fuses for memory and has been experimentally verified in a commercial CMOS process to operate with 500 V or higher human body model (HBM) discharges. Experimental studies of metal fuses are also presented and provide information on short-duration metal interconnect failure limits in addition to the ESD event-detection goal. It is found that thin aluminum traces in an IC (e.g., 0.25-1-μm-width metal-1) may withstand from 50 to > 100 mA for periods exceeding several seconds or minutes, values in excess of 100 times the typically used long-term reliability electromigration limit of 1 mA/μm. For fuses used in the detection circuit, reliable fuse blowing is achieved at HBM ESD currents as low as 0.3 A using either transmission-line-pulse or full-voltage discharges (100-pF capacitance at 500 V discharged through 1500-Ω series resistance).