Journal of the Korean Crystal Growth and Crystal Technology (한국결정성장학회지)

The Korea Association of Crystal Growth (한국결정성장학회)
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Formation of amorphous Ga2O3 thin films on Ti metal substrates by MOCVD and characteristics of diodes

MOCVD에 의한 Ti 금속 기판 위의 비정질 Ga2O3 박막 형성과 다이오드 특성

  • Nam Jun Ahn (Department of Nano Semiconductor Engineering, Korea Maritime and Ocean University) ;
  • Jang Beom An (Department of Nano Semiconductor Engineering, Korea Maritime and Ocean University) ;
  • Hyung Soo Ahn (Department of Nano Semiconductor Engineering, Korea Maritime and Ocean University) ;
  • Kyoung Hwa Kim (Department of Nano Semiconductor Engineering, Korea Maritime and Ocean University) ;
  • Min Yang (Department of Nano Semiconductor Engineering, Korea Maritime and Ocean University)
  • 안남준 (한국해양대학교 나노반도체공학과) ;
  • 안장범 (한국해양대학교 나노반도체공학과) ;
  • 안형수 (한국해양대학교 나노반도체공학과) ;
  • 김경화 (한국해양대학교 나노반도체공학과) ;
  • 양민 (한국해양대학교 나노반도체공학과)
  • Received : 2023.06.23
  • Accepted : 2023.07.20
  • Published : 2023.08.31
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Abstract

Ga2O3 thin films were deposited on Ti substrates using metal organic chemical vapor deposition (MOCVD) at temperatures ranging from 350 to 500℃. Lower deposition temperatures were chosen to minimize thermal deformation of the Ti substrate and its impact on the Ga2O3 film. Film surfaces tended to become rough at temperatures below 500℃ due to three-dimensional growth, but the film formed at 500℃ had the most uniform surface. All deposited films were amorphous in structure. Vertical Schottky diodes were fabricated and I-V and C-V measurements were performed. I-V measurements showed higher operating voltages compared to a typical SBD for films grown at different temperatures. The sample grown at 500℃, which had the most uniform surface, exhibited the lowest operating voltage. Higher growth temperatures resulted in higher capacitance values according to C-V measurements.

Ga2O3 박막은 금속 유기 화학기상증착법을 사용하여 Ti 기판에 350~500℃ 범위의 비교적 낮은 온도로 증착되었다. 낮은 온도를 선택하여 Ti 기판의 열적 변형과 Ga2O3 박막에 미치는 영향을 최소화하였다. 500℃ 이하에서 박막 형성 시, 기판 표면에서 원자들의 확산에너지가 충분하지 못하여 박막 표면이 3차원 성장으로 인해 거칠어지는 경향을 보였다. 그러나 500℃에서 형성된 박막은 2차원 박막 형태로 형성되었으며 비교적 균일한 표면을 가지고 있음을 확인하였다. 모든 증착된 박막은 비정질 구조였다. Ti 금속 기판 위에 형성된 Ga2O3 박막 위에 금속 전극을 형성하여 수직 쇼트키 다이오드를 제작하였으며, 제작된 다이오드의 전류-전압(I-V) 및 캐패시턴스-전압(C-V) 특성을 평가하였다. I-V 측정 결과, 대부분의 다이오드 소자에서 매우 높은 동작 전압을 나타냈으며, 비교적 균일한 표면을 갖는 500℃에서 성장한 샘플은 가장 낮은 동작 전압을 가짐을 확인할 수 있었다. 또한, C-V 측정 결과, 박막의 성장 온도가 높을수록 커패시턴스 값이 증가하는 것을 확인할 수 있었다.

Keywords

Acknowledgement

이 논문은 2022년도 정부(산업통상자원부) 및 한국산업기술평가관리원의 지원을 받아 수행된 연구이며(RS-2022-00154720, Si-on-SiC 구조기반 차세대전력 반도체 개발), 2021년 정부(산업통상자원부)의 재원으로 한국산업기술진흥원의 지원을 받아 수행된 연구입니다(P0012451, 2021년 산업전문인력역량강화사업).

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