18 research outputs found
Study on Zn-chalcogenide semiconductor grown by molecular beam epitaxy
Get PDF본 연구에서는 고품질 화합물 반도체 성장을 위한 성장 온도, Ⅵ/Ⅱ 비, 성장 속도와 같은 성장 조건의 결정, 이종 기판 위에 성장한 박막의 특성 분석, 저온 버퍼층의 역할, ZnTe와 같은 큰 부정합을 가지는 이종 에피층 성장에 대한 적용에 대해 알아 보았다.
Zn-chalcogenide를 박막으로 하였으며 기판은 GaAs를 사용하였으며 제 1장에서는 분자빔 에피탁시을 이용한 이종 에피 성장에 대한 이론과 일반적 성장 조건, 버퍼층의 역할에 대해 설명하였으며 종래 연구를 통해 성장 조건 최적화의 중요성에 대해 설명하였다. 제 2장에서는 MBE 시스템과 RHEED, HRXRD, AFM, PL, PC의 원리를 설명하였다. 제 3장에서는 ZnSe 박막의 물리적 특성에 대해 알아보았다. 성장 조건을 결정하기 위해 기판의 온도를 보정하였으며 등가분자선 압력과 성장 속도에 대해 조사하였다. 제 4장에서는 ZnSe 박막을 GaAs 기판 위에 성장시킨 저온 버퍼층 위에 성장시켰으며 저온 버퍼층 성장 속도의 역할을 알아보기 위해 다른 성장 속도에서 성장시켰다. 저온 버퍼층은 박막의 결정성과 불순물 확산을 고려하여 최적화되어야 함을 알 수 있었다. 제 5장에서는 GaAs 기판 위에 성장된 ZnTe의 성장 동역학에 대해 RHEED, AFM을 통해 알아보았으며, 성장 속도와 박막의 두께는 성장 동역학에 영향을 미치고 표면을 거칠게 하였다. 제 6장에서는 각 장에서의 결과를 토대로 요약하여 결론을 내렸다.In this paper, it has been investigated that how to determine the growth conditions such as the growth temperature, the ratio of Ⅵ/Ⅱ and the growth rate for the growth of high quality compound semiconductors, how to characterize the quality of grown film on heterosubstrates, what is the role of low-temperature buffer layer and how can those information be applied to the growth of heteroepitaxial layer with large mismatches such as ZnTe. It has been discussed in terms of optical, electrical, interfacial and structural properties.
In this thesis Zn-chalcogenides are selected as a thin film material and GaAs is used as a substrate. In the chapter 1, theoretical background of heteroepitaxial growth by MBE, the general growth conditions of MBE and the roles of buffer layer are explained and the importance of the optimization of the growth conditions is explained based on the previous studies. In the chapter 2, the MBE system and the principles of RHEED, HRXRD, AFM, PL and PC are explained. In the chapter3, the physical properties of the ZnSe films are investigated. To determine the growth conditions, a temperature of the substrate is adjusted and the beam equivalent pressure and the growth rate are measured. In the chapter 4, the ZnSe films are grown on the low-temperature buffer layer grown on GaAs substrate. To investigate a role of the growth rate during the low temperature buffer growth, two samples were prepared with different growth rates, It was found that the growth rate during the growth of low-temperature buffer layer should be optimized in terms of crystallinity of the film and impurity interdiffucion. In the chapter 5, the growth kinetics of ZnTe grown on the GaAs substrate has been investigated using RHEED and AFM measurement. The growth rate and film thickness give an effect on the growth kinetics and the roughness is originated on the growth kinetics. In the chapter 6, based on the results obtained from these chapters are summarized and concluded.제 1 장 서론 = 1
1.1 연구배경 = 1
1.2 종래연구 = 2
1.2.1 분자선 에피탁시의 성장 조건 = 2
1.2.2 저온 버퍼층 = 5
참고문헌 = 5
제 2 장 실험방법 = 7
2.1 분자선 에피탁시 = 7
2.1.1 서론 = 7
2.1.2 분자선 에피탁시 시스템 = 7
2.1.3 Reflection high energy electron diffraction = 9
2.2 High resolution X-ray diffraction = 13
2.3 Atomic force microscopy = 15
2.4 Photoluminescence spectroscopy = 15
2.5 Photocurrent spectroscopy = 22
참고문헌 = 22
제 3 장 성장 조건의 결정과 GaAs 기판 위에 성장된 ZnSe 박막의 특성 = 24
3.1 서론 = 24
3.2 실험 = 24
3.3 결과 및 토론 = 25
3.3.1 성장 조건 = 25
3.3.2 Atomic force microscopy = 27
3.3.3 High resolution X-ray diffraction = 28
3.3.4 Photoluminescence spectroscopy = 28
3.3.5 Photocurrent spectroscopy = 32
3.4 결론 = 36
참고문헌 = 36
제 4 장 저온 ZnSe 버퍼층의 효과 = 38
4.1 서론 = 38
4.2 실험 = 39
4.3 결과 및 토론 = 40
4.3.1 Reflection high energy electron diffraction = 40
4.3.2 High resolution X-ray diffraction = 40
4.3.3 Atomic force microscopy = 43
4.3.4 Photoluminescence spectroscopy = 47
4.4 결론 = 48
참고문헌 = 48
제 5 장 GaAs 기판 위에 성장된 ZnTe의 특성 = 51
5.1 서론 = 51
5.2 실험 = 51
5.3 결과 및 토론 = 52
5.3.1 Reflection high energy electron diffraction = 52
5.3.2 Atomic force microscopy = 54
5.4 결론 = 58
참고문헌 = 58
제 6 장 결론 = 59
Appendix A = 60
참고문헌 = 61
감사의 글 = 6
A Study on the Driving Methods and Circuits for Image Quality Enhancement in AMOLED Displays
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개방 어휘 핵심어 검출을 위한 단어의 음성-텍스트 표현 기법에 관한 연구
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STRUCTURE FOR IMPROVING ANTENNA ISOLATION CHARACTERISTICS
No full text본 발명은 송신·수신 안테나의 격리도를 향상시키기 위한 구조물에 관한 것으로, 송,수신 신호의 분리도를 향상시킬수 있는 구조물을 설치하여 실내형의 소형/초소형 중계기와 외장형 중계기에 적용 가능한 안테나를 구현하는 것을 목적으로 한다
유전 상수를 측정하기 위한 장치와 방법
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