Assessing Zener-Diode-Structure Reliability From Zener Diodes' Low-Frequency Noise

An electrical-stress test has been conducted on 98 Zener conventional reference diode structures, and it has been observed that 45% of these devices failed after 3000 h. However, this high failure ratio can be reduced to below 25%, or less, provided that an appropriate low-frequency-noise (LFN) characterization is initially performed and that all the devices exhibiting a larger LFN are subtracted from the lot subjected to electrical-stress test. Further results obtained after a 4500-h electrical-stress test conducted on a reduced number of diodes fully validate this finding.