Integrating automated diagnosis into the testing and failure analysis operations

The authors have integrated an AD system into the manufacturing flow for several key semiconductor products at Texas Instruments and have found the results to be both accurate and beneficial. The number of devices diagnosed to date remains relatively small, and further work will be required in order to perform AD on a larger scale. It is believed that AD system accuracy could be further improved through the use of nonclassical fault models such as bridging faults. Another useful feature would be the addition of a capability to generate patterns specifically for the purpose of distinguishing between faults, and to be able to generate those patterns "on the fly" as a device is being diagnosed. Finally, diagnosis based on IDDQ testing may prove to be an effective isolation technique.