Systems and methods for detecting watermark formations on semiconductor wafers
US8580696B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 27, 2007 |
| Grant date | Nov 12, 2013 |
| Priority date | — |
| Expiry date | Jul 8, 2031 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/67253
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
Systems and methods for detecting watermark formations on semiconductor wafers are described. In one embodiment, a method comprises providing a semiconductor wafer having at least one watermark sensitive region fabricated thereon, subjecting the wafer to a wet processing step, enhancing a susceptibility to detection of at least one watermark formation created on the at least one watermark sensitive region, and detecting the at least one watermark formation. In another embodiment, a method comprises growing a first oxide layer on a surface of a semiconductor wafer, patterning a watermark sensitive structure on the first oxide layer, depositing a silicon layer over the first oxide layer, doping a region of the silicon layer over the watermark sensitive structure with an impurity to create a watermark sensitive region that is prone to retaining watermark formations as result of a wet processing step, and growing a second oxide layer over the silicon layer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.