Non-contact method for acquiring charge-voltage data on miniature test areas of semiconductor product wafers
US7202691B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Jul 27, 2005 |
| Grant date | Apr 10, 2007 |
| Priority date | — |
| Expiry date | Jul 27, 2025 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01R29/24
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A non-contact method is described for acquiring the accurate charge-voltage data on miniature test sites of semiconductor wafer wherein the test sites are smaller than 100 μm times 100 μm. The method includes recognizing the designated test site, properly aligning it, depositing a prescribed dose of ionic charge on the surface of the test site, and precise measuring of the resulting voltage change on the surface of the test site. The method further compromises measuring of the said voltage change in the dark and/or under strong illumination without interference from the laser beam employed in the Kelvin Force probe measurement of the voltage. The method enables acquiring of charge-voltage data without contacting the measured surface of the wafer and without contaminating the wafer. Thus, the measured wafer can be returned to IC fabrication line for further processing.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.