Paper
14 February 2008 Characterization of absorptance losses in optical materials using a high resolution Hartmann-Shack wavefront sensor
Author Affiliations +
Abstract
Lens heating due to absorbed UV laser radiation can diminish the achievable spatial resolution of the lithographic process in semiconductor wafer steppers. At the Laser- Laboratorium Göttingen a measurement system for quantitative registration of this thermal lens effect was developed. It is based upon a strongly improved Hartmann-Shack wavefront sensor with extreme sensitivity, accomplishing precise online monitoring of wavefront deformations of a collimated test laser beam transmitted through the laser-irradiated site of a sample. Caused by the temperature-dependent refractive index as well as thermal expansion, the formerly plane wavefront of the test laser is distorted to form a rotationally symmetric valley, being equivalent to a convex lens. The observed wavefront distortion is a quantitative measure of the absorption losses in the sample. Thermal theory affords absolute calibration of absorption coefficients.
© (2008) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
A. Bayer, F. Barkusky, U. Leinhos, T. Miege, B. Schäfer, and K. Mann "Characterization of absorptance losses in optical materials using a high resolution Hartmann-Shack wavefront sensor", Proc. SPIE 6879, Photon Processing in Microelectronics and Photonics VII, 68791S (14 February 2008); https://doi.org/10.1117/12.762579
Advertisement
Advertisement
RIGHTS & PERMISSIONS
Get copyright permission  Get copyright permission on Copyright Marketplace
KEYWORDS
Absorption

Wavefronts

Quartz

Thermal effects

Wavefront distortions

Wavefront sensors

Deep ultraviolet

Back to Top