On new current signatures and adaptive test technique combination

This paper proposes new current signatures for test purposes. It estimates their capabilities in the detection of additional current caused by weak resistive active and passive defects, when used separately and in combination with other current-based test techniques. Estimation results based in part on actual I/sub DDQ/ measurements show that current-based test technique combinations allow reliable detection of smaller current deltas and offsets. The extra margin provided by these combinations can also be used to reduce the yield losses associated to current-based test techniques by applying these test techniques more conservatively while keeping the same detection capabilities. The cost of adding a second set of I/sub DDQ/ test patterns can be greatly reduced if part of an adaptive test strategy.