Outgassing from photoresists illuminated by extreme ultraviolet radiation can lead to degradation of the very expensive multilayer-coated optics in an extreme ultraviolet stepper. Reliable quantification of the various organic molecules outgassed by photoresists has been a challenging goal. We have designed a compact system for this measurement. In the first step, the total number of molecules emitted by the photoresist is measured using a pressure-rise method in a closed vacuum chamber, with the pressure measured by mechanical means using a capacitance displacement gauge. To provide identification and relative abundances, the outgassed molecules are then collected in an evacuated trap cooled by liquid nitrogen for subsequent analysis by gas chromatography with mass spectrometry. We will discuss the design and performance of the system.
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http://dx.doi.org/10.6028/jres.114.011 | DOI Listing |
Spectrochim Acta A Mol Biomol Spectrosc
January 2025
Key Laboratory of Spectral Imaging Technology, Xi'an Institute of Optics and Precision Mechanics, Chinese Academy of Sciences, Xi'an 710119 China. Electronic address:
Non-optically active water quality parameters (NAWQPs) are essential for surface water quality assessments, although automated monitoring methods are time-consuming, include labor-intensive chemical pretreatment, and pose challenges for high spatiotemporal resolution monitoring. Advancements in spectroscopic techniques and machine learning may address these issues. We integrated ultraviolet-visible-near infrared absorption spectroscopy with physical-chemical measurements to predict total nitrogen (TN), dissolved oxygen (DO), and total phosphorus (TP) in the Yangtze River Basin, China.
View Article and Find Full Text PDFThe design of the illumination optics for high numerical aperture (NA) anamorphic extreme ultraviolet (EUV) projection optics is a critical challenge to EUV lithography in advanced technology node. However, the EUV illumination optics design using conventional methods have flaws in illumination efficiency and illumination uniformity due to the limitations of relay configuration and matching method that can only consider one factor affecting illumination uniformity. One-mirror configuration can improve illumination efficiency by reducing the number of mirrors.
View Article and Find Full Text PDFWe theoretically study high-order harmonic generation (HHG) involving an extreme ultraviolet (XUV) pulse and an intense infrared driving field, where the electron is ionized by absorbing a single XUV photon. Using a developed classical-trajectory model that includes Coulomb effects and the improved initial conditions, it is demonstrated that the resulting harmonic emission times match well with those obtained by applying the Gabor transform to data from numerical solutions of time-dependent Schrödinger equations for helium and hydrogen atoms. This confirms a classical HHG scheme under single-photon ionization: The electron, ionized by absorbing one XUV photon, oscillates in the infrared field and may recollide with the parent ion, emitting high-frequency radiation.
View Article and Find Full Text PDFThis erratum corrects the affiliation addresses of authors of our paper [Opt. Express32, 43748 (2024).10.
View Article and Find Full Text PDFWe present the subcycle spectral structures from attosecond transient absorption spectra of helium by accurately solving the full three-dimensional time-dependent Schrödinger equation in extreme ultraviolet attosecond pulse and an orthogonally polarized infrared (IR) laser field. We discover that the subcycle spectral features associated with the dressed 1 ( ≥ 4) states and light-induced states, referred to as , , and , can be strongly modified or even enhanced when the strength ratio of the orthogonal laser field in two polarized laser directions changes. To understand the spectral evolution of the subcycle structures, we perform calculations of the time-dependent population and time-frequency analysis.
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