Method and apparatus for detecting a polishing endpoint based upon infrared signals
US6241847A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 30, 1998 |
| Grant date | Jun 5, 2001 |
| Priority date | — |
| Expiry date | Jun 30, 2018 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L21/3212
- WIPO fieldMachine tools
- WIPO sectorMechanical engineering
Abstract
A method of polishing a first layer of a semiconductor wafer down to a second layer of the semiconductor wafer is disclosed. One step of the method includes polishing the first layer of the semiconductor wafer with a polishing surface having a chemical slurry positioned thereon. The polishing step causes an infrared spectrum to be emitted through the semiconductor wafer. Another step of the method includes detecting a rate of change of intensity level of the infrared spectrum and generating a control signal in response thereto. The method also includes halting the polishing step in response to generation of the control signal. Polishing systems are also disclosed which determine a polishing endpoint for a semiconductor wafer based upon an infrared spectrum generated due to a chemical slurry reacting with the semiconductor wafer.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.