Interferometric-spatial-phase imaging for sub-nanometer three-dimensional positioning

Current alignment technology is incapable of satisfying the needs of imminent generations of lithography. This dissertation delineates a novel method of alignment and three-dimensional position metrology that is compatible with many forms of proximity lithography. The method is called Interferometric-Spatial-Phase Imaging (ISPI), and is based on encoding three-dimensional position information in the spatial phase and frequency of interference fringes, viewed with specialized oblique-incidence, dark-field optical microscopes. Alignment detectivity is <0.5 nm, and detection range is >500 gm. Unlike amplitude-based interferometers, this spatial-phase-encoding interferometer achieves high alignment detectivity without sensitivity to variations in wavelength, gap and other factors, such as resist layers and changes in the index of refraction in the beampath. Several novel gap detection methods are introduced, with gap detectivity <1 nm, measured over gaps between <1 am and >500 jgm.

Department dc:contributor.department

Massachusetts Institute of Technology. Dept. of Electrical Engineering and Computer Science.

Grantor dc:publisher

Massachusetts Institute of Technology

Year dc:date.issued

2004

Author dc:creator

• Moon, Euclid E. (Euclid Eberle), 1965-

Advisor dc:contributor.advisor

• Henry I. Smith.

• Electrical Engineering and Computer Science.

Statement dc:rights

• M.I.T. theses are protected by copyright. They may be viewed from this source for any purpose, but reproduction or distribution in any format is prohibited without written permission. See provided URL for inquiries about permission.

Licence dc:rights.uri

• http://dspace.mit.edu/handle/1721.1/7582

Language dc:language.iso

eng

Handle dc:identifier.uri

http://hdl.handle.net/1721.1/34563

OAI identifier oai:identifier

oai:dspace.mit.edu:1721.1/34563