Defect isolation using scan-path testing and electron beam probing in multi-level high density asics
US5663967A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Oct 19, 1995 |
| Grant date | Sep 2, 1997 |
| Priority date | — |
| Expiry date | Oct 19, 2015 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG06F11/2273
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method and apparatus for isolating faults in an integrated circuit reduces time and effort to precisely locate such faults. A fault dictionary is developed, which is a record of the errors a circuit's modeled faults are expected to cause. The fault dictionary need only be generated once, and can be recalled for later testing of the same design. A failing circuit is subjected to test vectors and the erroneous outputs are logged, and then all failing scan test vectors are mapped into simulation scan patterns. Faults in the circuit are localized to a more narrowly defined area in which faults in the circuit may occur. If the area, even after localization, is too large, additional test patterns are developed and the device is subjected to another round of tests. The redefinition of test patterns is repeated until possible fault locations are sufficiently localized. The device is then probed to precisely locate the fault(s).
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.