In-situ endpoint detection method and apparatus for chemical-mechanical polishing using low amplitude input voltage
US5337015A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 14, 1993 |
| Grant date | Aug 9, 1994 |
| Priority date | — |
| Expiry date | Jun 14, 2013 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01D5/2405
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
An in-situ thickness monitoring/endpoint detection method and apparatus for chemical-mechanical polishing (CMP) of a dielectric layer on a top surface of a semiconductor wafer is disclosed. The apparatus comprises center and guard electrodes and associated electronic circuitry, including a high frequency, low voltage signal generating means, for converting a current which is inversely proportional to the dielectric layer thickness into a corresponding analog voltage. A position detection device triggers an analog-to-digital converter to convert the analog voltage into a digital signal while the wafer is located within a detection region as the wafer is being polished. A control means gathers the digital signals corresponding to the thickness data for processing and CMP device control.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.