Apparatus and method for determining clamping status of semiconductor wafer
US7073383B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | May 9, 2002 |
| Grant date | Jul 11, 2006 |
| Priority date | — |
| Expiry date | Aug 29, 2022 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N2291/2698
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An apparatus determines how well a semiconductor wafer (4) is clamped to a support member (1). The apparatus has at least one ultrasonic transducer (2a,2b,2c,2d) configured to emit ultrasonic energy (3) toward an interface between the water (4) and the support member (1) so that the interface generates echo signals, and a data processing unit (11) configured to analyze the echo signals to arrive at a determination as to how well the semiconductor wafer (4) is clamped to the support member (1before semiconductor process is started. A first method ensures that a wafer (4) is securely clamped to a support member before a semiconductor process is started. A second method verifies proper de-clamping of a semiconductor wafer (4) from a support member (1) before the semiconductor wafer (4) is removed from the support member (1) upon completion of a semiconductor process.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.