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Abstract—Recent advances in process technology have resulted in novel defect mechanisms making the test generation process very challenging. In addition to complete opens and shorts that can be represented via extreme defect resistance magnitudes, partial resistive opens and shorts are also of concern in deeply scaled CMOS technologies. For open defects with intermediate defect magnitude values, it has been shown that multi-pattern tests are necessary for defect exposure. We extend this approach to short defects with intermediate defect magnitude values to obtain a suite of multi-pattern tests for standard cell instances that cover complete as well as partial intra-cell open and short defects. A hierarchical scan-compatible SAT-based test generation approach for full scan sequential circuits is then proposed that allows such multi-pattern tests to be applied to the circuit via the scan infrastructure. A key innovation is the combined use of shift and capture operations along with launch-on-capture and launch-on- shift scan based test application for increased defect coverage. Resulting defect coverage improvements over conventional two-pattern tests are demonstrated on ISCAS89 benchmark circuits.
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Enhanced DFT for Fortuitous Detection of Transition Faults During Scan Shift
Transition fault testing is an important component of modern testing for delay defects. Unfortunately, test pattern sets for delay defects tend to be significantly longer than test pattern sets for static defects. In the past, various approaches have been devised to detect static defects during scan shift to reduce test time and increase defect coverage. In this paper, we propose a DFT (Design-For-Test) enhancement to allow delay defects to be detected by stuck-at test patterns during scan shift as well.
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- PAR ID:
- 10356398
- Date Published:
- Journal Name:
- 2022 IEEE 31st Microelectronics Design & Test Symposium (MDTS)
- Page Range / eLocation ID:
- 1 to 6
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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- Free Publicly Accessible Full Text
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Accepted Manuscript1.0
- Conference Paper:
- https://doi.org/10.1109/MDTS54894.2022.9826976
