Three dimensional characterization of silicon wafer Vias from combined on-top microscopic and bottom-through laser fringes measurement
US9513112B1 · kind B1 · utility
1Cited by
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18Claims
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Key dates
| Filing date | Aug 22, 2014 |
| Grant date | Dec 6, 2016 |
| Priority date | — |
| Expiry date | Oct 24, 2034 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B2210/56
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A collimated laser beam is directed towards the wafer bottom such that the impinging light is partially forward deflected along the vias' bottom edges. Concentric laser interference fringes occur on the wafer top from constructive and destructive interference between the forward deflected and directly through propagating laser. A top down optical image from a number of vias' top openings and a top down fringe image from the same vias' concentric fringe sets are processed to three dimensionally characterize the vias.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.