Out-of-band exposure characterization with the SEMATECH Berkeley 0.3-NA microfield exposure tool

Journal Article · Mon Feb 23 04:00:00 EST 2009 · Journal of Micronano Lithography, MEMS and MOEMS

DOI:https://doi.org/10.1117/12.814429· OSTI ID:960237

George, Simi A; Nauleau, Patrick; Rekawa, Senajith; Gullikson, Eric; Kemp, Charles D

For the commercialization of extreme ultraviolet lithography (EUVL), discharge or laser produced, pulsed plasma light sources are being considered. These sources are known to emit into a broad range of wavelengths that are collectively referred to as the out-of-band (OOB) radiation by lithographers. Multilayer EUV optics reflect OOB radiation emitted by the EUV sources onto the wafer plane resulting in unwanted background exposure of the resist (flare) and reduced image contrast. The reflectivity of multilayer optics at the target wavelength of 13.5 nm is comparable to that of their reflectivity in the deep ultraviolet (DUV) and UV regions from 100-350 nm. The aromatic molecular backbones of many of the resists used for EUV are equally absorptive at specific DUV wavelengths as well. In order to study the effect of these wavelengths on imaging performance in a real system, we are in the process of integrating a DUV source into the SEMATECH Berkeley 0.3-NA Microfield Exposure Tool (MET). The MET plays an active role in advanced research in resist and mask development for EUVL and as such, we will utilize this system to systematically evaluate the imaging impact of DUV wavelengths in a EUV system. In this paper, we present the optical design for the new DUV component and the simulation-based imaging results predicting the potential impact of OOB based on known resist, mask, and multilayer conditions. It should be noted that because the projection optics work equally well as imaging optics at DUV wavelengths, the OOB radiation cannot be treated simply as uniform background or DC flare.

• Research Organization: Ernest Orlando Lawrence Berkeley National Laboratory, Berkeley, CA (US)
• Sponsoring Organization: Materials Sciences Division
• DOE Contract Number: AC02-05CH11231
• OSTI ID: 960237
• Report Number(s): LBNL-1652E
• Journal Information: Journal of Micronano Lithography, MEMS and MOEMS, Journal Name: Journal of Micronano Lithography, MEMS and MOEMS
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
AROMATICS
COMMERCIALIZATION
DESIGN
LASERS
LIGHT SOURCES
OPTICS
PERFORMANCE
PLASMA
RADIATIONS
REFLECTIVITY
TARGETS
WAVELENGTHS