Method and apparatus for endpoint detection for chemical mechanical polishing
US6106662A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 8, 1998 |
| Grant date | Aug 22, 2000 |
| Priority date | — |
| Expiry date | Jun 8, 2018 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB24D7/12
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
An apparatus to generate an endpoint signal to control the polishing of thin films on a semiconductor wafer surface includes a through-hole in a polish pad, a light source, a fiber optic cable, a light sensor, and a computer. A pad assembly includes the polish pad, a pad backer, and a pad backing plate. The pad backer includes a pinhole and a canal that holds the fiber optic cable. The pad backer holds the polish pad so that the through-hole is coincident with the pinhole opening. A wafer chuck holds a semiconductor wafer so that the surface to be polished is against the polish pad. The light source provides light within a predetermined bandwidth. The fiber optic cable propagates the light through the through-hole opening to illuminate the surface as the pad assembly orbits and the chuck rotates. The light sensor receives reflected light from the surface through the fiber optic cable and generates reflected spectral data. The computer receives the reflected spectral data and calculates an endpoint signal. For metal film polishing, the endpoint signal is based upon the intensities of two individual wavelength bands. For dielectric film polishing, the endpoint signal is based upon fi…
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.