Apparatus and methods for detecting transitions of wafer surface properties in chemical mechanical polishing for process status and control
US6937915B1 · kind B1 · utility
Assignee
Inventors
Key dates
| Filing date | Mar 28, 2002 |
| Grant date | Aug 30, 2005 |
| Priority date | — |
| Expiry date | Jan 24, 2023 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB24B49/14
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
In chemical mechanical polishing apparatus, a wafer carrier plate is provided with a cavity for reception of a sensor positioned very close to a wafer to be polished. Energy resulting from contact between a polishing pad and an exposed surface of the wafer is transmitted only a very short distance to the sensor and is sensed by the sensor, providing data as to the nature of properties of the exposed surface of the wafer, and of transitions of those properties. Correlation methods provide graphs relating sensed energy to the surface properties, and to the transitions. The correlation graphs provide process status data for process control.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.