Measurement of steep aspheres: a step forward to nanometer accuracy

Ingolf Weingaertner; Michael Schulz; Peter Thomsen-Schmidt; Clemens Elster

doi:10.1117/12.450095

10 December 2001 Measurement of steep aspheres: a step forward to nanometer accuracy

Ingolf Weingaertner, Michael Schulz, Peter Thomsen-Schmidt, Clemens Elster

Proceedings Volume 4449, Optical Metrology Roadmap for the Semiconductor, Optical, and Data Storage Industries II; (2001) https://doi.org/10.1117/12.450095
Event: International Symposium on Optical Science and Technology, 2001, San Diego, CA, United States

Abstract

It is a promising method for measuring steep aspheres and complex surfaces with nanometer and sub-nanometer accuracy to measure the curvature and to calculate the topography from it, since unlike slope and distance, the curvature is an intrinsic property of a surface and less insensitive to error influences. For the development of a measuring instrument based on the physical property of curvature, various topics have been investigated. The method described does not rely on external form references, and the errors of the scanning stages and the whole-body movement of the artifact have only little influence on the accuracy. In comparison to other measuring techniques, it is an advantageous feature of the curvature measuring technique that distance and angle between sensor and surface element can be controlled and kept constant during scanning as it is the curvature and not the distance or the slope which is the measurand. This leads to the result that, apart from the calibration of the curvature sensor, the whole system no longer suffers from first-and second-order errors. The uncertainty budget shows that nanometer accuracy is achievable.

Citation Download Citation

Ingolf Weingaertner, Michael Schulz, Peter Thomsen-Schmidt, and Clemens Elster "Measurement of steep aspheres: a step forward to nanometer accuracy", Proc. SPIE 4449, Optical Metrology Roadmap for the Semiconductor, Optical, and Data Storage Industries II, (10 December 2001); https://doi.org/10.1117/12.450095

ACCESS THE FULL ARTICLE

INSTITUTIONAL
Select your institution to access the SPIE Digital Library.

SELECT YOUR INSTITUTION

PERSONAL
Sign in with your SPIE account to access your personal subscriptions or to use specific features such as save to my library, sign up for alerts, save searches, etc.

PERSONAL SIGN IN

No SPIE Account? Create one

PURCHASE THIS CONTENT

SUBSCRIBE TO DIGITAL LIBRARY

50 downloads per 1-year subscription

Members: $195

Non-members: $335 ADD TO CART

25 downloads per 1 - year subscription

Members: $145

Non-members: $250 ADD TO CART

PURCHASE SINGLE ARTICLE

Includes PDF, HTML & Video, when available