Abstract
IDDQ testing is a well-known test method to filter dies with reliability risks. However, the test method is endangered by the increase in off-state current in advanced process technologies. An alternative for detecting resistive shorts is very-low voltage (VLV) testing. This test method tests dies at a strongly reduced supply voltage. The smaller the supply voltage the higher the sensitivity for defects. This paper investigates if VLV testing can replace IDDQ testing. To obtain a significant increase in defect coverage one has to use a supply voltage below 2 ? VT. In the experiments a supply voltage of 1.5 ? VT was used with relaxed timing. This makes the method more than twice as sensitive compared to 2 ? VT and allows one to detect shorts with resistance of five times the detection limit at the nominal supply voltage. However, even with these settings we were only capable to detect a small fraction of the IDDQ anomalies. Therefore VLV is not suited to replace IDDQ testing.