Failure Mechanisms in Semiconductors

To ATTAIN maximum reliability and availability in the operation of large computing systems, the reliability of subsystems and components must be maintained at a high level. Inasmuch as the major portion of all system failures may be traced ultimately to the component level, Burroughs Corporation has seen fit to fund a substantial reliability effort in the area of component failure analysis, which has, over the past several years, paid for itself through increased system reliability and effective extension of the life of computers already in the field. Studies are not limited to components already in use, but as promising new devices become available, sample quantities are obtained, tested, and often deliberately failed in various ways to determine the most probable failure mode. From these studies, much valuable data and information has been obtained which has, in turn, been of great value to the procurement and design activities in selecting best components available for a particular job. Much of the work accomplished has been, of necessity, associated with semiconductor devices. Much data on failure modes of other components has been accumulated also, but for the purposes of presentation, it is proposed to limit the discussion to semiconductors¿heir failure modes and the means for determining these failure modes.