Cell-aware experiences in a high-quality automotive test suite

Abstract

High quality is an absolute necessity for automotive designs. This paper describes an approach to improve the overall defect coverage for CMOS-based high quality automotive designs. We present results from a cell-aware (CA) characterization flow for 216 cells, the pattern generation flow for a 130nm smart power design, and high-volume production test results achieved after testing multimillion parts. The idea behind CA tests is to detect cell-internal (CI) bridges, opens, leaking and high resistive transistor defects which are undetected with state-of-the-art tests. The production test results have shown that the CA tests detect various failing parts during a first wafer sort test which still resulted into unique failing parts after a second wafer sort test done at a different temperature and with additional tests. The obtained results encouraged us to continue this work beyond this paper to run further experiments with the final goal to eliminate the stuck-at (SA) and transition delay (TR) test by simultaneously improving the quality with CA tests which are a superset of SA and TR tests.