Stuck-Open Fault Leakage and Testing in Nanometer Technologies

The stuck-open fault (SOF) is a difficult, hard failure mechanism unique to CMOS technology. Its detection requires a specific 2-vector pair that examines each transistor in the logic gate for an open defect in its drain and/or source. In this work it is shown that this failure mechanism is very alive and relevant to modern technologies. The small nanometer technology capacitances and the increased leakage currents result in faster discharges of the floating high impedance node making fault detection more difficult. A test vector strategy is proposed to improve the detection of this fault for technologies with gate current leakage.