• Title/Summary/Keyword: critical dimension

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Fractal kinetic characteristics of uranium leaching from low permeability uranium-bearing sandstone

  • Zeng, Sheng;Shen, Yuan;Sun, Bing;Tan, Kaixuan;Zhang, Shuwen;Ye, Wenhao
    • Nuclear Engineering and Technology
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    • v.54 no.4
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    • pp.1175-1184
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    • 2022

  • The pore structure of uranium-bearing sandstone is one of the critical factors that affect the uranium leaching performance. In this article, uranium-bearing sandstone from the Yili Basin, Xinjiang, China, was taken as the research object. The fractal characteristics of the pore structure of the uranium-bearing sandstone were studied using mercury intrusion experiments and fractal theory, and the fractal dimension of the uranium-bearing sandstone was calculated. In addition, the effect of the fractal characteristics of the pore structure of the uranium-bearing sandstone on the uranium leaching kinetics was studied. Then, the kinetics was analyzed using a shrinking nuclear model, and it was determined that the rate of uranium leaching is mainly controlled by the diffusion reaction, and the dissolution rate constant (K) is linearly related to the pore specific surface fractal dimension (DS) and the pore volume fractal dimension (DV). Eventually, fractal kinetic models for predicting the in-situ leaching kinetics were established using the unreacted shrinking core model, and the linear relationship between the fractal dimension of the sample's pore structure and the dissolution rate during the leaching was fitted.

  • https://doi.org/10.1016/j.net.2021.10.013 인용 PDF KSCI

MIAO-TAM EQUATION ON ALMOST COKÄHLER MANIFOLDS

  • Mandal, Tarak
    • Communications of the Korean Mathematical Society
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    • v.37 no.3
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    • pp.881-891
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    • 2022

  • In the present paper, we have studied Miao-Tam equation on three dimensional almost coKähler manifolds. We have also proved that there does not exist non-trivial solution of Miao-Tam equation on the said manifolds if the dimension is greater than three. Also we give an example to verify the deduced results.

  • https://doi.org/10.4134/CKMS.c210225 인용 PDF KSCI

Reflectivity Control at Substrate / Photoresist Interface by Inorganic Bottom Anti-Reflection Coating for Nanometer-scaled Devices

  • Kim, Sang-Yong;Kim, Yong-Sik
    • Transactions on Electrical and Electronic Materials
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    • v.15 no.3
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    • pp.159-163
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    • 2014

  • More accurate CD (Critical Dimension) control is required for the nanometer-scaled devices. However, since the reflectivity between substrate and PR (Photoresist) becomes higher, the CD (Critical Dimension) swing curve was intensified. The higher reflectivity also causes PR notching due to the pattern of sub-layer. For this device requirement, it was optimized for the thickness, refractive index(n) and absorption coefficient(k) in the bottom anti-reflective coating(BARC; SiON) and photoresist with the minimum reflectivity. The computational simulated conditions, which were determined with the thickness of 33 nm, n of 1.89 and k of 0.369 as the optimum condition, were successfully applied to the experiments with no standing wave for the 0.13um-device. At this condition, the lowest reflectivity was 0.44%. This optimum condition for BARC SiON film was applied to the process for 0.13um-device. The optimum SiON film as BARC to PR and sub-layer could be formed with the accurate CD control and no standing waver for the nanometer-scaled semiconductor manufacturing process.

  • https://doi.org/10.4313/TEEM.2014.15.3.159 인용 PDF KSCI

SUBMICRON TECHNOLOGY OF SINGLE LAYER PHOTO-RESIT (단층RESIST의 미세패턴형성기술)

  • Bae, Kyung-Sung;Hong, Seung-Kag
    • Proceedings of the KIEE Conference
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    • 1988.07a
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    • pp.315-318
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    • 1988

  • THE STUDY ABOUT CHARACTERISTICS OF PHOTO RESIST ITSELF (MINIMUM RESOLUTION, DEPTH OF FOCUS MARGIN AND CRITICAL DIMENSION CONTROL LATITUDE) WAS DONE AND REPORTED. THREE TYPES OF PHOTO RESISTS WERE TESTED. THE FIRST IS THE LOW MOLECULAR WEIGHT PHOTO-RESIST SHOWING THE NARROW DISTRIBUTION OF MOLECULAR WEIGHT (LOW MOLECULAR WEIGHT CONTROL TYPE), THE SECOND IS A PHOTO-RESIST CONTAINING THE INNER CONTRAST ENCHANCEMENT MATERIAL (INNER CEM TYPE) AND THE THIRD IS A NORMAL PHOTO-RESIST (HIGH MOLECULAR WEIGHT TYPE). THE INNER CEM TYPE AND THE LOW MOLECULAR WEIGHT CONTROL TYPE PHOTO-RESIST ARE MORE IMPROVED PHOTO-RESISTS. IT PROVED THAT THE MINIMUM RESOLUTION WAS IMPROVED BY 0.2 - 0.3 um, THE DEPTH OF FOCUS MARGIN WAS IMPROVED BY 0.8 - 1.2 um AND THE C.D. CONTROL LATITUIDE WAS IMPROVED.

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