MOCVD에 의한 Ti 금속 기판 위의 비정질 Ga₂O₃ 박막 형성과 다이오드 특성
Formation of amorphous Ga2O3 thin films on Ti metal substrates by MOCVD and characteristics of diodes
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Ga₂O₃ 박막은 금속 유기 화학기상증착법을 사용하여 Ti 기판에 350~500°C 범위의 비교적 낮은 온도로 증착되었다. 낮은 온도를 선택하여 Ti 기판의 열적 변형과 Ga₂O₃ 박막에 미치는 영향을 최소화하였다. 500°C 이하에서 박막 형성시, 기판 표면에서 원자들의 확산에너지가 충분하지 못하여 박막 표면이 3차원 성장으로 인해 거칠어지는 경향을 보였다. 그러나 500°C에서 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°C에서 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.
Abstract
Ga₂O₃ thin films were deposited on Ti substrates using metal organic chemical vapor deposition (MOCVD) at temperatures ranging from 350 to 500°C. 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°C due to three-dimensional growth, but the film formed at 500°C 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°C, which had the most uniform surface, exhibited the lowest operating voltage. Higher growthtemperatures resulted in higher capacitance values according to C-V measurements
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