Automatic gain control
US7494929B2 · kind B2 · utility
Assignee
Inventors
Key dates
| Filing date | Apr 27, 2006 |
| Grant date | Feb 24, 2009 |
| Priority date | — |
| Expiry date | Apr 27, 2026 |
Classification
- Technology area (CPC B)Performing Operations; Transporting
- CPC primaryB24B55/00
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
Methods and apparatus for automatic gain control. A film on a substrate is polished by a chemical mechanical polisher that includes a polishing pad and an in-situ monitoring system. The polishing pad includes a first portion, and the in-situ monitoring system includes a light source and a light detector. The light source emits light, and light emitted from the light source is directed through the first portion and to a surface of the film being polished. Light reflecting from the surface of the film being polished and passing through the first portion is received at the light detector. An electronic signal is generated based on the light received at the light detector. When the electronic signal is evaluated not to satisfy one or more constraints, a gain for the light detector is adjusted so that the electronic signal would satisfy the one or more constraints.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.