New chemical mechanical planarization (CMP) end point detection apparatus
US5667424A · kind A · utility
Assignee
Inventor
Key dates
| Filing date | Sep 25, 1996 |
| Grant date | Sep 16, 1997 |
| Priority date | — |
| Expiry date | Sep 25, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/26
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A chemical mechanical planarization polishing machine that includes a means for the detection of planarization end point is described. The chemical mechanical planarization polishing machine includes a workpiece carrier to hold and rotate a semiconductor wafer workpiece. The semiconductor wafer workpiece is placed in contact with a rotating polishing pad onto which an abrasive slurry is dispensed. A light emitting means directs a beam of light onto the workpiece carrier. The beam of light is reflected to a positional sensing means that detects variation in the position of the reflected beam of light as the workpiece vibrates due to irregularities in the surface of the workpiece. The positional information of the variation of the reflected beam of light is transferred to a calculating means that will determine the planarization end point from changes in magnitude and frequency of the positional information and a predetermined relationship between the vibration of the workpiece and the planarization end point.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.