서지주요정보
YBCO/MgO 박막의 초고주파 특성과 BST/YBCO/STO 박막의 제조 및 분석 = A study on the microwave characteristics of YBCO/MgO film and fabrication and characterization of BST/YBCO/STO film
서명 / 저자 YBCO/MgO 박막의 초고주파 특성과 BST/YBCO/STO 박막의 제조 및 분석 = A study on the microwave characteristics of YBCO/MgO film and fabrication and characterization of BST/YBCO/STO film / 최종완.
저자명 최종완 ; Choi, Jong-Wan
발행사항 [대전 : 한국과학기술원, 1999].
Online Access 원문보기 원문인쇄

소장정보

등록번호

8009387

소장위치/청구기호

학술문화관(문화관) 보존서고

MMS 99046

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초록정보

The deposition process, the microstructure and electrical characteristics of YBCO/MgO and BST/YBCO/STO structures were investigated for the applications of microwave devices. $YBa_2Cu_3O_x$(YBCO) thin films on MgO substrate were deposited with Pulsed Laser Deposition method. YBCO films grown at 760℃ and 400mtorr showed c-axis orientation and had RMS roughness of 99Å, critical temperature of 91K. Microstrip transmission lines in the form of an open-ended half wavelength resonator were fabricated with YBCO films deposited on MgO substrates. The effects of etching time and film thickness on critical temperature, roughness and microwave property were investigated. As etching time increased, edge roughness and surface resistance increased. Because microwave current flow in the edge of the line, the edge roughness change which have small areal fraction caused the large change of surface resistance. As the film thickness increased, critical temperature increased upto 92K and saturated, the surface roughness continued to increase, and the surface resistance decreased to 23.52mΩ and saturated. Above saturation point, the penetration depth is not function of roughness, and the surface resistance is not function of the ratio of the film thickness to the penetration depth. The YBCO film deposited on STO had RMS roughness of 89Å, critical temperature of 91.2K and best in-plane orientation in the deposition condition study. BST was deposited on YBCO/STO by ECR PEMOCVD. (h00) BST growed on (00ℓ) YBCO/ STO (h00). $(Ba_xY_{1-x})($Ti_yY_{1-y})TiO_3$ phase were generated at interface between YBCO and BST in BST deposition. Because of the low oxygen pressure in BST deposition, the superconductivity was disappeared. But the superconductivity was restored after the oxygen annealing at 550℃. Since electrical Cu path existed in Ba rich BST, loss in Ba rich BST was more than that in Sr rich BST after oxygen annealing. Electrical property measured at room temperature involved not only BST also YBCO electrode property. As temperature decreased, effects of the YBCO electrode to capacitance decreased.

서지기타정보

서지기타정보
청구기호 {MMS 99046
형태사항 iv, 106 p. : 삽도 ; 26 cm
언어 한국어
일반주기 저자명의 영문표기 : Jong-Wan Choi
지도교수의 한글표기 : 노광수
지도교수의 영문표기 : Kwang-Soo No
학위논문 학위논문(석사) - 한국과학기술원 : 재료공학과,
서지주기 참고문헌 : p. 103-104
주제 YBCO 박막
BST
초고주파
습식 식각
박막 두께
YBCO
BST
Microwave
Wet etching
Thickness
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