Electrostatic charge measurement on semiconductor wafers
US6781205B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Oct 11, 2002 |
| Grant date | Aug 24, 2004 |
| Priority date | — |
| Expiry date | Dec 23, 2022 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/67253
- WIPO fieldSemiconductors
- WIPO sectorElectrical engineering
Abstract
An enclosure for transporting semiconductor wafers includes a pair of sensors that are responsive to electrostatic fields mounted on conductive grounded plates in facing orientations on opposite sides of a position within the enclosure at which a semiconductor wafer is to be located. Electronic circuitry within the enclosure in communication with the sensors supplies monitoring signals to remote circuitry external to the enclosure that isolates sources of contaminants and provides remote balance and gain adjustments. Calibration of the balance and gain adjustments uses a grounded plate for zero balance reference, and uses a plate of insulating material that is charged to a known potential for referencing gain adjustments to produce related outputs.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.