Method and computer program for efficient cell failure rate estimation in cell arrays
US7380225B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 14, 2006 |
| Grant date | May 27, 2008 |
| Priority date | — |
| Expiry date | Mar 14, 2026 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG11C2029/0403
- WIPO fieldComputer technology
- WIPO sectorElectrical engineering
Abstract
A method and computer program for efficient cell failure rate estimation in cell arrays provides an efficient mechanism for raising the performance of memory arrays beyond present levels/yields. An initial search is performed across cell circuit parameters to determine failures with respect to a set of performance variables. For a single failure region the initial search can be a uniform sampling of the parameter space and when enough failure points have been accumulated, a mean is chosen from the mean of the detected failure points. Mixture importance sampling (MIS) is then performed to efficiently estimate the single failure region. For multiple failure regions, a particular failure region is selected by varying the memory circuit cell parameters along a random set of vectors until failures are detected, thus identifying the boundary of the failure region of interest as the closest failure region. A new mean is chosen for MIS in conformity with the location of the detected boundary.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.