System and method for optically measuring a structure
US5880838A · kind A · utility
Assignee
Inventors
Key dates
| Filing date | Jun 5, 1996 |
| Grant date | Mar 9, 1999 |
| Priority date | — |
| Expiry date | Jun 5, 2016 |
Classification
- Technology area (CPC G)Physics
- CPC primaryG01B2290/70
- WIPO fieldMeasurement
- WIPO sectorInstruments
Abstract
A system and method for measuring the dimensions of a small (e.g., microelectronic) structure. The present invention is an optical system and method that uses a polarized light beam, reflected off or transmitted through, a structure, to measure the structural parameters, such as the lateral dimensions, vertical dimensions, height, or the type of structural material. The system employs a light source to generate a light beam that is polarized and focused onto the structure to be measured. The structure is illuminated with TE and TM polarized light. The structure is dimensioned such that the TM and TE fields are affected differently by the diffraction off the structure. As a result, either the TE or TM field can be used as a reference to analyze the phase and amplitude changes in the other field. Differences between the diffracted TE and TM far fields allow a comparison of the relationship between the amplitude and phase of those fields to determine the structural parameters of a structure.
Source: USPTO / EPO open patent data. Objective bibliographic and citation counts.