Optimization of chemical mechanical process by detection of oxide/nitride interface using CLD system
US6254453A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Sep 30, 1999 |
| Grant date | Jul 3, 2001 |
| Priority date | — |
| Expiry date | Sep 30, 2019 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01N21/76
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A method is provided to optimize the chemical mechanical planarization process of wafers having a target removal layer and a stop layer. A slurry is added to a polishing table which includes a polishing pad and a platen adapted for rotation; a portion of the slurry is allowed to engage an interface between the polishing pad and the wafer. A gaseous sample is continuously extracted from the slurry; the gaseous sample includes a reactant product created when the polishing pad engages the stop layer. The gaseous sample is introduced into a reactant product detector. A first time is determined, corresponding to an initial detection of the reactant product in the slurry, thereby creating a first reference point. A second time is determined, corresponding to the detection of a maximum volume of the reactant in said slurry, thereby creating a second reference point. The first and second reference points are then processed to obtain a signal, wherein the signal reflects the uniformity of removal of the layer containing the reactant product.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.