Method of ellipsometric measurement, an ellipsometer and device for controlling the carrying out of layers using such method and apparatus
US5666200A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Feb 27, 1996 |
| Grant date | Sep 9, 1997 |
| Priority date | — |
| Expiry date | Feb 27, 2016 |
Classification
- Technology area (CPC H)Electricity
- CPC primaryH01L22/12
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
This invention relates to a method and a device for the ellipsometric measurement of physical parameters representative of a sample. The measured values I.sub.om, I.sub.sm and I.sub.cm are calculated (51, 52) from the signal (50) which represents the measured intensity I(t). In a first step (55, 57), initial theoretical values I.sub.st /I.sub.ot and I.sub.ct /I.sub.ot are produced from initial estimations (56) of the physical parameters. In a second step (58, 59) subsequent estimations (59) of physical parameters are determined from which subsequent theoretical values I.sub.st /I.sub.ot and I.sub.ct /I.sub.ot are deduced (55, 57). The second step is reiterated to an Nth estimation (59) of the physical parameters, so as to minimise the difference between the theoretical values and those measured. The physical parameters are evaluated (54) in the course of the Nth estimation.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.