Binning for IC Quality: Experimental Studies on the SEMATECH Data

The earlier smaller bipolar study did not provide a high enough bin 0 population to directly observe test escapes and thereby estimate defect levels for the best bin. Results presented here indicate that the best bin can be reasonably expected to show a 2 - 5 factor improvement in defect levels over the average for the lot for moderate to high yields (the overall yield for these experiments was approximately 65%). The experiments also confirm the dependence of the best bin quality on test transparency. The defect level improvement is poorer for the case Of IDDQ escapes where the tests applied had a much higher escape rate. Overall experimental results are consistent with analytical projections for typical values of the clustering parameter in [9]. The final version of this paper will include extensive analysis to validate the analytical models based on this data

MINVDD Testing for Weak CMOS ICs

A weak chip is one that contains flaws -- defects that do not interfere with correct circuit operation at normal conditions but may cause intermittent or early-life failures. MINVDD testing can detect weak CMOS chips. The minvdd of a chip is the minimum supply voltage value at which a chip can function correctly. It can be used to differentiate between good chips and weak chips. In the first part of this paper, we will study several types of flaws to demonstrate the effectiveness of MINVDD testing. Experimental results show that MINVDD testing is as effective as VLV testing for screening out burn-in rejects