Multi-Aperture Shower Design for the Improvement of the Transverse Uniformity of MOCVD-Derived GdYBCO Films

Ruipeng Zhao; Qing Liu; Yudong Xia; Fei Zhang; Yuming Lu; Chuanbing Cai; Bowan Tao; Yanrong Li

doi:10.3390/ma10091088

Multi-Aperture Shower Design for the Improvement of the Transverse Uniformity of MOCVD-Derived GdYBCO Films

Materials (Basel). 2017 Sep 15;10(9):1088. doi: 10.3390/ma10091088.

Authors

Ruipeng Zhao¹, Qing Liu², Yudong Xia³, Fei Zhang⁴, Yuming Lu⁵, Chuanbing Cai⁶, Bowan Tao⁷, Yanrong Li⁸

Affiliations

¹ State Key Lab of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China. zhaoruipeng1990@sina.com.
² State Key Lab of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China. liuqing0435@gmail.com.
³ School of Physical Science and Technology, Southwest Jiaotong University, Chengdu 610031, China. ydxia@swjtu.edu.cn.
⁴ Chengdu Fine Optical Engineering Research Center, Chengdu 610041, China. zfchunri@163.com.
⁵ School of Physics, Shanghai University, Shanghai 200444, China. ymlu@staff.shu.edu.cn.
⁶ School of Physics, Shanghai University, Shanghai 200444, China. cbcai@shu.edu.cn.
⁷ State Key Lab of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China. taobw@uestc.edu.cn.
⁸ State Key Lab of Electronic Thin Films and Integrated Devices, University of Electronic Science and Technology of China, Chengdu 610054, China. yrli@uestc.edu.cn.

Abstract

A multi-aperture shower design is reported to improve the transverse uniformity of GdYBCO superconducting films on the template of sputtered-LaMnO₃/epitaxial-MgO/IBAD-MgO/solution deposition planarization (SDP)-Y₂O₃-buffered Hastelloy tapes. The GdYBCO films were prepared by the metal organic chemical vapor deposition (MOCVD) process. The transverse uniformities of structure, morphology, thickness, and performance were characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), step profiler, and the standard four-probe method using the criteria of 1 μV/cm, respectively. Through adopting the multi-aperture shower instead of the slit shower, measurement by step profiler revealed that the thickness difference between the middle and the edges based on the slit shower design was well eliminated. Characterization by SEM showed that a GdYBCO film with a smooth surface was successfully prepared. Moreover, the transport critical current density (J_c) of its middle and edge positions at 77 K and self-field were found to be over 5 MA/cm² through adopting the micro-bridge four-probe method.

Keywords: GdYBCO; MOCVD; critical current; morphology; multi-aperture shower.