Latent damage in CMOS devices from single-event latchup

Evaluation of several types of CMOS devices after nondestructive latchup revealed structural changes in interconnects that appears to be due to localized ejection of part of the metallization due to melting. This is a potential reliability hazard for CMOS devices because it creates localized voids within interconnects that reduce the cross section by one to two orders of magnitude in the damaged region. These effects must be considered when testing devices for damage from latchup, as well as in establishing limits for current detection and shutdown as a means of latchup protection.