Cold delay defect screening

Delay defects can escape detection during the normal production test flow; particularly if they do not affect any of the long paths included in the test flow. Some delay defects can have their delay increased, making them easier to detect, by carrying out the test with a very low supply voltage (VLV testing). However, VLV testing is not effective for delay defects caused by high resistance interconnects. This paper presents a screening technique for such defects. This technique, cold testing, relies on carrying out the test at low temperature. One particular type of defect, silicide open, is analyzed and experimental data are presented to demonstrate the effectiveness of cold testing.