Spectrometric method for analysis of film thickness and composition on a patterned sample
US5900633A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Dec 15, 1997 |
| Grant date | May 4, 1999 |
| Priority date | — |
| Expiry date | Dec 15, 2017 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B11/0625
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A fast and practical method for the analysis of patterned samples of semiconductor integrated circuits, and other materials, determines the thickness and composition of layers fabricated during manufacture. The method employs a measurement spot that is sufficiently large to irradiate areas of two or more different regions of the sample that result from its patterned features, generally at replicable locations. In carrying out the method, one or more of reflectance, transmittance, and radiance spectrance is measured, and the various parameters characterizing the thickness and composition in the patterned areas are obtained using, for example, a model-based analysis of the polarization and amplitude of the emanating radiation, the model parameters being iteratively adjusted to achieve a match with measured values. The method can be made fast and practical by using measurements that are taken both before and also after treatment steps are effected, and/or by using measurements from the same location on designated samples undergoing the same process, to reduce the number of unknown parameters in a reference model.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.