주석을 도핑한 비화학양론 산화갈륨 박막의 제조 및 특성 분석
- Author(s)
- 이하람
- Issued Date
- 2020
- Abstract
- Ga2O3는 약 4.9 eV의 넓은 bandgap을 가진 반도체로서 광전자 장치, 가스 센서 등과 같은 다양한 응용 분야에서 적용된다. 그러나 유전체 물질로서의 potential 또한 고려되고 있어 금속 산화물 반도체 전계 효과 트랜지스터가 연구되고 있다. 본 논문에서는 sapphire(0001) 기판에 고주파 분말 스퍼터링을 사용하여 증착된 multi-domain Sn이 도핑된 Ga2O3 박막들의 heteroepitaxial 성장을 연구한다. Ga2O3:Sn 박막은 Ar gas 분위기에서 증착되기 때문에 산소 결핍 상태인 비화학양론 Ga2O3-x로 성장한다. SnO2의 영향으로 Ga2O3-x는 산소 결핍을 채우나 여전히 Ga2O3-x의 형태로 존재한다. 고해상도 싱크로트론 x-선 회절을 사용하여 박막의 결정질 배향을 조사한다. Sn이 도핑된 Ga2O3 박막은 높은 결정도와 모자이크 구조로 성장하였다. Ga2O3의 corundum α- 및 monoclinic β- 상이 as-grown 샘플에서 공존한다는 것을 발견된다. Ga2O3:Sn 박막의 α 및 β 상이 sapphire(0001) 기판에 epitaxial 관계라는 것을 발견된다. epitaxial 관계는 out-of-plane 방향에서 β-Ga2O3[-201] // α-Ga2O3[0001] // sapphire[0001]과 in-plane 방향에서 β-Ga2O3[020] // α-Ga2O3[10-10] // sapphire[11-20]로 요약한다. In-plane β-Ga2O3(020) 및 α-Ga2O3(30-30) 브래그 피크들의 방위각 스캔은 α-Ga2O3과 β-Ga2O3 둘 다 12-fold in-plane 회전 대칭을 나타내며 특히 in-plane 방향에서 30〫 회전된 α-Ga2O3 domain은 사파이어[11-20]방향으로 ± 3〫 기울어진다. 본 연구의 12-fold symmetry 분석은 이전연구의 대부분 α-Ga2O3 및 β-Ga2O3 박막들에 대한 6-fold symmetry만 연구된 것에 비해 주목할 만하다. 또한, 박막의 두께 증가 및 SnO2 함량이 증가함에 따라 광학 bandgap은 점차 감소하였고, 이는 Sn 원자의 양 증가에 기인한다. |Ga2O3 is a semiconductor with a wide bandgap of about 4.9 eV and is applied in various application such as electronic devices and gas sensors.
However, the potential as a dielectric material is also considered, and recently, metal oxide semiconductor field effect transistors have been studied. In this study, we reports the heteroepitaxial growth of multidomain Sn-doped Ga2O3 thin films deposited using radio frequency powder sputtering onto sapphire(0001) substrates. Since the Ga2O3:Sn thin film is deposited tn an Ar gas atmosphere, it grows into a non-stoichiometric Ga2O3-x oxygen vacancy state. Under the influence of SnO2, Ga2O3-x fills oxygen deficiency but still exists in the form of Ga2O3-x. The crystalline orientation of the films was examined using high-resolution synchrotron x-ray diffraction. The Sn-doped Ga2O3 thin films were grown with remarkably high crystallinity and negligible mosaic structure. We found that the corundum α- and monoclinic β-phase of
Ga2O3 coexisted in the as-grown samples. We found that both α and β phases of Ga2O3:Sn are epitaxial to the sapphire(0001) substrates. Epitaxial relationship can be summarized as β-Ga2O3[-201] // α-Ga2O3[0001] // sapphire[0001] in the out-of-plane direction and β-Ga2O3[020] // α -Ga2O3[10-10] // sapphire[11-20] in the in-plane direction. Azimunthal angle scans of the in-plane β-Ga2O3(020) and α-Ga2O3(30-30) bragg peaks revealed that the α-Ga2O3 and β-Ga2O3 both showed 12-fold in-plane rotational symmetry and, in particular, that the 30〫 rotated α-Ga2O3 domains in the in-plane direction were tilted ±3〫to the sapphire[11-20] direction. It is noteworthy that only 6-fold symmetry has previously been reported for most α-and β-Ga2O3 thin films. Finally, as the thickness of the thin film increases or as the SnO2 content increases, the optical bandgap gradually decreases, which is due in part to the increase in the amount of Sn atoms, but the
effect of the defects is greater.
- Alternative Title
- Synthesis and characterization of Sn-doped non-stoichiometric Ga2O3-x thin films grown
- Alternative Author(s)
- Haram Lee
- Department
- 일반대학원 첨단소재공학과
- Advisor
- 강현철
- Awarded Date
- 2020-02
- Table Of Contents
- 목 차
제 1 장 서론 ····································································1
제 2 장 실험방법 ····························································3
제 2.1 절 시간에 따른 Ga2O3:Sn 박막의 증착 ············· 3
제 2.2 절 SnO2 함량에 따른 Ga2O3:Sn 박막의 증착 · 4
제 2.3 절 Ga2O3:Sn 박막의 특성 분석 ····························5
제 3 장 결과 및 고찰 ···················································9
제 3.1 절 시간에 따른 Ga2O3:Sn 박막 ····························9
1. High quality Ga2O3:Sn thin film ·································9
2. SEM analysis of Ga2O3:Sn thin films ····················11
3. XRD analysis of 850 ㎚ thickness ···························15
4. UV-VIS-IR spectroscopy analysis ··························18
제 3.2 절 SnO2 함량에 따른 Ga2O3:Sn 박막 ·············· 21
1. SEM analysis of Ga2O3:Sn thin films ····················21
2. XRD analysis of Ga2O3:Sn thin films ···················· 27
3. UV-VIS-IR spectroscopy analysis ··························38
제 4 장 결론 ··································································· 41
참고문헌 ··········································································42
- Degree
- Master
- Publisher
- 조선대학교 대학원
- Citation
- 이하람. (2020). 주석을 도핑한 비화학양론 산화갈륨 박막의 제조 및 특성 분석.
- Type
- Dissertation
- URI
- https://oak.chosun.ac.kr/handle/2020.oak/14192
http://chosun.dcollection.net/common/orgView/200000278123
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