I/O interface latchup analysis using optical and electrical testing

The I/O interface latchup analysis using optical and electrical testing was discussed. JEDEC78 testing procedure, an automated computer-controlled latchup test program, was developed for the analysis. Emission of microscopy was used to characterize the ignition and diffusion of latchup in a series of I/O pins of a test chip. The results show that minority carriers can diffuse underneath lines of decoupling capacitances, if the recombination length of the minority carriers is comparable with the size of the capacitance.