Methods and apparatus for detecting removal of thin film layers during planarization
US5872633A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 12, 1997 |
| Grant date | Feb 16, 1999 |
| Priority date | — |
| Expiry date | Feb 12, 2017 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/12
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
The present invention provides methods and apparatus which permit the in-process, in-situ, substantially real time measurement of the actual thickness of a surface layer of a work piece, e.g., a semiconductor wafer. A probe is disposed proximate to the outer perimeter of a polishing pad on a CMP table such that the probe establishes optical contact with the wafer surface as a portion of the wafer extends beyond the outer perimeter of the polishing pad. A nozzle may be provided to apply a stream of compressed air at the disk surface under inspection to thereby remove excess slurry from the local region of the workpiece being inspected. A broad band light source is employed in conjunction with a fiber optic cable to direct light at the wafer surface. A bifurcated probe is employed such that the light applied to the workpiece surface is reflected back to and captured by a corresponding optical sensor connected to a fiber optic cable. The captured reflected light received by the receptor sensor and fiber optic cable assembly is applied to a photospectrum meter which analyzes the reflected light. An output signal from the photospectrum meter is transmitted to a processor which includes …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.