Abstract
We developed an extreme ultraviolet (EUV) scatterometer equipped with a table-top EUV source for the characterization of nanoscale grating lines. Appropriate orders of high-harmonic generation at wavelengths ranging from 25 to 35 nm are selected as the coherent light source for high-resolution spatial performance. It is shown that the grating surface profile significantly affects the scattered diffraction intensities and can be retrieved by the structure reconstruction algorithms using inverse modeling by rigorous coupled wave analysis.
Highlights
Scatterometry is an optical metrology technique designed for analyzing the changes of light intensity in a device
The scatterometers used in the semiconductor industry are typically specular spectroscopic systems, which work at a fixed angle of incidence but in broadband wavelengths range in the visible or UV, and measure only the zeroth-order diffraction
The diffraction angles were calculated from arctangent of jxi − x0j∕R, where jxi − x0j is the distance between the diffraction peaks (m 1⁄4 Æ1) and the CCD center
Summary
Scatterometry is an optical metrology technique designed for analyzing the changes of light intensity in a device. The scatterometers used in the semiconductor industry are typically specular spectroscopic systems, which work at a fixed angle of incidence but in broadband wavelengths range in the visible or UV, and measure only the zeroth-order diffraction. In contrast to variableangle and specular spectroscopic scatterometries, the proposed extreme ultraviolet (EUV) scatterometer is designed to measure the intensity of nonzeroth-order diffraction at a fixed incident angle and at multiple laser-like wavelengths. A microscopic translation stage, for mounting the CCD, was designed to adjust the distance between the grating target and the CCD detector in a range of 25.0 to 40.5 mm This allows both the m 1⁄4 þ1 and −1 diffracted beams to be directly and simultaneously collected by the CCD camera with maximal spatial resolution. The comparison with CD measurements using a cross-sectional scanning electron microscope (SEM) showed a good correlation of the results
Sign-in/Register to view highlights & summary Sign-in/Register to access full text options 
Talk to us
Join us for a 30 min session where you can share your feedback and ask us any queries you have
Schedule a callDisclaimer: All third-party content on this website/platform is and will remain the property of their respective owners and is provided on "as is" basis without any warranties, express or implied. Use of third-party content does not indicate any affiliation, sponsorship with or endorsement by them. Any references to third-party content is to identify the corresponding services and shall be considered fair use under The CopyrightLaw.
