In situ monitoring technique and apparatus for chemical/mechanical planarization endpoint detection
US5081421A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | May 1, 1990 |
| Grant date | Jan 14, 1992 |
| Priority date | — |
| Expiry date | May 1, 2010 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B7/345
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
This invention provides an in situ monitoring technique and apparatus for chemical/mechanical planarization end point detection in the process of fabricating semiconductor or optical devices. Fabrication of semiconductor or optical devices often requires smooth planar surfaces, either on the surface of a wafer being processed or at some intermediate stage e.g. a surface of an interleaved layer. The detection in the present invention is accomplished by means of capacitively measuring the thickness of a dielectric layer on a conductive substrate. The measurement involves the dielectric layer, a flat electrode structure and a liquid interfacing the article and the electrode structure. Polishing slurry acts as the interfacing liquid. The electrode structure includes a measuring electrode, an insulator surrounding the measuring electrode, a guard electrode and another insulator surrounding the guard electrode. In the measurement a drive voltage is supplied to the measuring electrode, and in a bootstrap arrangement to a surrounding guard electrode, thereby measuring the capacitance of the dielectric layer of interest without interferring effect from shunt leakage resistance. The process …
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.