Nonclassical faults in CMOS digital integrated circuits

Miscellaneous · Mon Jan 01 00:00:00 EST 1990

OSTI ID:6155999

Millman, S D

Modern VLSI circuits are harder to test than their predecessors for two reasons. First, sheer size has made the number of potential defects, as well as the number of possible test patterns, exceedingly large. Second, the stuck-at fault model, used extensively in the past, does not model all the types of failures that can occur in CMOS circuits. This dissertation investigates the consequences of testing DOS circuits with single stuck-at test sets when failures that can not be modeled with single stuck-at faults occur. In addition, properties of test sets that achieve high fault coverage of bridging, stuck-open, and transition faults are identified. Simulation results show that short, cleverly derived, stuck-at test sets provide poor bridging fault coverage, while pseudo-exhaustive and pseudo-random test sets provide excellent coverage when generated properly. Techniques for generating these tests are described, and their effectiveness in detecting bridging faults is compared. It is often necessary to determine why a chip has failed during test. This thesis shows that the traditional approach to diagnosing stuck-at faults with fault dictionaries generated for stuck-at faults is not appropriate for diagnosing CMOS bridging faults. A new technique for using stuck-at fault dictionaries to diagnose bridging faults is described. Using this technique, bridging faults in the circuits used for this research are effectively diagnosed even with reduced stuck-at fault dictionaries. This thesis shows that even short stuck-at test sets can provide the stuck-open 75% fault coverage required by the DOD. In addition, it is shown that node activity, a measure of how often nodes in the circuit change value, is as important as the length of the test for detecting stuck-open faults.

• Research Organization: Stanford Univ., CA (USA)
• OSTI ID: 6155999
• Resource Relation: Other Information: Thesis (Ph.D)
• Country of Publication: United States
• Language: English

Related Subjects

99 GENERAL AND MISCELLANEOUS//MATHEMATICS, COMPUTING, AND INFORMATION SCIENCE
SEMICONDUCTOR STORAGE DEVICES
PERFORMANCE TESTING
COMPUTERIZED SIMULATION
DIGITAL CIRCUITS
DIGITAL COMPUTERS
FAILURE MODE ANALYSIS
COMPUTERS
ELECTRONIC CIRCUITS
MEMORY DEVICES
SEMICONDUCTOR DEVICES
SIMULATION
SYSTEM FAILURE ANALYSIS
SYSTEMS ANALYSIS
TESTING
990200* - Mathematics & Computers