7 July 1997 Measurement of mid-spatial-frequency scatter in extreme ultraviolet lithography systems using direct aerial image measurements
Author Affiliations +
Abstract
The technique of direct aerial image measurements (AIM) is applied to the evaluation of the mid-spatial frequency scatter produced form an extreme ultraviolet (EUV) laser plasma based microlithography testbed at Sandia National Laboratories in Livermore, Calif. AIM provides an at-wavelength technique for the in-situ characterization of the EUV images produced from the Scharzchild 10X reduction camera. The AIM technique measures the aerial images of the system by sampling the light intensity that passes through a narrow scanning slit (90 nm) and impinges upon a silicon photodiode designed to have a high quantum efficiency at EUV wavelengths. The measurements scan the slit artifact at the image plane across a step-function aerial image generated by the 10X reduction camera. The results of these measurements produce a measurement of the baseline scattered light and the modulation transfer function (MTF). Comparison of the measured MTF with simulated MTFs produces a measure of the combined multi-layer surface roughness variance ((sigma) rms2).
© (1997) COPYRIGHT Society of Photo-Optical Instrumentation Engineers (SPIE). Downloading of the abstract is permitted for personal use only.
Charles H. Fields, Avijit K. Ray-Chaudhuri, Kevin D. Krenz, William G. Oldham, Richard H. Stulen, "Measurement of mid-spatial-frequency scatter in extreme ultraviolet lithography systems using direct aerial image measurements", Proc. SPIE 3048, Emerging Lithographic Technologies, (7 July 1997); doi: 10.1117/12.275798; https://doi.org/10.1117/12.275798
PROCEEDINGS
12 PAGES


SHARE
Back to Top