Thickness Monitoring of nm Period EUV Multilayer Fabrication by Ellipsometry

Journal Article · Wed May 12 04:00:00 EDT 2004 · AIP Conference Proceedings

DOI:https://doi.org/10.1063/1.1757900· OSTI ID:20653054

Tsuru, Toshihide; Tsutou, Takashi; Hatano, Tadashi; Yamamoto, Masaki ^[1]

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1. Research center for soft X-ray microscopy, IMRAM, Tohoku University, 2-1-1 Katahira, Aoba-ku, Sendai, Miyagi 980-8577 (Japan)

We have adopted our new ellipsometer of picometer-thickness sensitivity for sputtering rate monitoring of extreme ultraviolet (EUV) multilayer fabrication. With real time thickness analysis during Mo/Si multilayer fabrication, the sputtering rates of Mo and Si were observed to be 0.9162nm/min and 4.752nm/min, respectively. EUV reflectance of this multilayer mirror was measured at the Photon Factory KEK and the period thickness was found to be 7.22nm. This period thickness is compared with an ellipsometric value of 6.98nm calculated by the final total thickness divided by the number of periods of 40. The difference of 3.3% can be attributed by a compound layer formation at every boundary of Mo and Si as observe by ellipsometry. The results proved good possibility of a single wavelength in-situ null ellipsometry for accurate and detailed controlling of the period thickness of EUV multilayer.

• OSTI ID: 20653054
• Journal Information: AIP Conference Proceedings, Journal Name: AIP Conference Proceedings Journal Issue: 1 Vol. 705; ISSN APCPCS; ISSN 0094-243X
• Country of Publication: United States
• Language: English

Related Subjects

46 INSTRUMENTATION RELATED TO NUCLEAR SCIENCE AND TECHNOLOGY
BEAM OPTICS
CONTROL
ELLIPSOMETRY
EXTREME ULTRAVIOLET RADIATION
FABRICATION
JAPANESE ORGANIZATIONS
LAYERS
MIRRORS
MONITORING
PHOTONS
REFLECTIVITY
SENSITIVITY
SPUTTERING
SYNCHROTRON RADIATION
THICKNESS
WAVELENGTHS