臺灣博碩士論文加值系統

本研究以霧化化學氣相沉積法（Mist-CVD）磊晶ε-氧化鎵薄膜，透過埋入式錫摻雜製作四種不同結構的氧化鎵元件，探討ε-氧化鎵半導體功率元件的電性表現，評估ε-氧化鎵作為半導體功率元件的可行性。
對ε-氧化鎵薄膜進行材料分析，確認以Mist-CVD沉積之氧化鎵薄膜為單晶ε-氧化鎵。在此基礎上，透過各項製程參數的優化分別製作出4種結構之ε-氧化鎵元件:埋入式錫摻雜平面氧化鎵MESFET（MES）、埋入式錫摻雜平面氧化鎵MOSFET（MOS）、埋入式錫摻雜掘入閘極氧化鎵MOSFET（RG-MOS）、雙層錫摻雜掘入閘極氧化鎵MESFET（DLRG-MES）。
研究結果表明，MES的低特徵導通電阻，證明埋入式錫摻雜能有效增加ε-氧化鎵的導電性，MOS則證明閘極氧化層能夠有效降低閘極漏電流，RG-MOS具有最低0.075 Ω·cm²的特徵導通電阻與高達6個數量級的開關電流比，顯示出掘入式閘極對控制元件通道具有極大的優勢，同時顯示出ε-氧化鎵具有作為半導體功率元件的潛力。而DLRG-MES的元件電性仍需驗證其可行性。
綜合電性的比較，RG-MOS具有整體最佳的電性表現，透過汲極偏壓應力測試，確認RG-MOS元件的穩定性。最終，將掘入閘極ε-氧化鎵MOSFET（RG-MOS）與相似結構的掘入閘極β-氧化鎵MOSFET進行比較，發現其在最大導通電流與開關電流比方面仍有成長空間，還能更進一步優化ε-氧化鎵之電性表現。
本研究為首次以霧化化學氣相沉積法製備掘入閘極ε-氧化鎵MOSFET，為ε-氧化鎵半導體功率元件提供初步的研究成果，研究成果顯示出ε-氧化鎵作為半導體功率元件在電性表現上具有巨大的潛力。

This study investigates the electrical performance of ε-Ga2O3 power devices fabricated through Mist Chemical Vapor Deposition (Mist-CVD) with buried tin doping. The feasibility of ε-Ga2O3 as a power device material is evaluated by creating four different structures and analyzing their electrical properties.
Material analysis confirmed that the Mist-CVD deposited films are single-crystal ε-Ga2O3. Based on the result, four ε-Ga2O3 devices were fabricated: Buried Tin-Doped Lateral Ga2O3 MESFET (MES), Buried Tin-Doped Lateral Ga2O3 MOSFET (MOS), Buried Tin-Doped Recessed Gate Ga2O3 MOSFET (RG-MOS), and Dual-Layer Tin-Doped Recessed Gate Ga2O3 MESFET (DLRG-MES).
The results indicate that the MES’s low specific on-resistance demonstrates that buried tin doping can effectively enhance the conductivity of ε-Ga2O3.The MOS device shows that the gate oxide layer can effectively reduce gate leakage current. The RG-MOS exhibits the lowest specific on-resistance of 0.075 Ω·cm² and an on-off current ratio exceeding six orders of magnitude, highlighting the significant advantage of the recessed gate in controlling the device channel.This also demonstrates the potential of ε-Ga₂O₃ as a semiconductor power device. However, the electrical performance of the DLRG-MES still requires further validation of its feasibility.
In a comprehensive comparison , the RG-MOS demonstrated superior performance. Compared to β-Ga2O3 MOSFETs with a similar structure, the RG-MOS shows competitive performance in electrical characteristics.
This study is the first to fabricate recessed gate ε-Ga2O3 MOSFET using Mist-CVD, providing preliminary results for ε-Ga2O3 power devices and demonstrating its significant potential as a power device material.

論文審定書 i
誌謝 ii
摘要 iii
Abstract iv
目錄 vi
圖目錄 x
表目錄 xiv
第一章 緒論 1
1-1前言 1
1-2氧化鎵功率元件的發展 5
1-3實驗動機 6
第二章 元件製程與實驗 8
2-1 製程參數與步驟 8
2-1-1 Mist-CVD磊晶氧化鎵與沉積二氧化錫薄膜(Deposition) 8
2-1-2微影(Photolithography) 9
2-1-3熱蒸鍍金屬沉積(Thermal Evaporation) 10
2-1-4舉離(Lift off) 11
2-1-5感應耦合式電漿反應離子蝕刻(ICP-RIE) 11
2-1-6爐管熱退火(Thermal annealing) 13
2-2實驗一 埋入式錫摻雜氧化鎵MESFET元件製程 14
2-3實驗二 埋入式錫摻雜氧化鎵MOSFET與掘入閘極氧化鎵MOSFET元件製程 16
2-3-1埋入式錫摻雜氧化鎵MOSFET元件製程 16
2-3-2埋入式錫摻雜掘入閘極氧化鎵MOSFET元件製程 18
2-4實驗三 雙層埋入式錫摻雜掘入閘極氧化鎵MESFET元件製程 21
第三章 材料分析與元件量測 24
3-1材料分析 24
3-1-1 X光繞射儀(X-Ray Diffraction) 24
3-1-2橢圓偏光儀(Ellipsometer) 28
3-1-3二次離子質譜分析儀(Secondary Ion Mass Spectrometry) 30
3-1-4穿透式電子顯微鏡(Transmission Electron Microscopy) 31
3-2元件電性量測 33
3-3汲極偏壓應力測試(Drain bias stress test) 35
第四章 實驗一 埋入式錫摻雜ε-氧化鎵MESFET基本電性分析 36
4-1 ε-氧化鎵磊晶參數對MESFET元件電性的影響分析 36
4-2埋入式錫摻雜參數對MESFET元件電性的影響分析 38
4-3埋入式錫摻雜ε-氧化鎵MESFET基本電性 40
第五章 實驗二 埋入式錫摻雜ε-氧化鎵MOSFE與掘入閘極ε-氧化鎵MOSFET基本電性分析 42
5-1埋入式錫摻雜ε-氧化鎵MOSFET基本電性 42
5-2感應耦合式電漿蝕刻參數對元件電性的影響分析 44
5-3埋入式錫摻雜掘入閘極ε-氧化鎵MOSFET基本電性 46
第六章 實驗三 雙層錫摻雜掘入閘極ε-氧化鎵MESFET基本電性分析 48
6-1退火製程對元件電性的影響分析 48
6-2蝕刻參數對元件電性的影響分析 51
6-3 ε-氧化鎵磊晶參數對元件電性的影響分析 53
6-4上層錫摻雜沉積時間對元件電性的影響分析 54
6-5雙層埋入式錫摻雜掘入閘極ε-氧化鎵MESFET基本電性 58
第七章 實驗結果與比較 60
7-1不同結構之ε-氧化鎵功率元件基本電性比較 61
7-1-1特徵導通電阻(Ron,sp)之比較 62
7-1-2閘極漏電流(IGS,off)之比較 66
7-1-3開關電流比(Ion/Ioff current ratio)之比較 69
7-1-4崩潰電壓(Vbr)之比較 70
7-1-5功率品質因素(PFOM)之比較 73
7-2 ε-氧化鎵功率元件穩定性-汲極偏壓應力測試 75
7-3氧化鎵功率元件之比較 78
第八章 結論與未來展望 81
8-1結論 81
8-2未來展望 83
第九章 參考文獻 84

[1]“Global EV Outlook 2024 – Analysis,” IEA. Accessed: Jun. 19, 2024. [Online]. Available: https://www.iea.org/reports/global-ev-outlook-2024
[2]J. Sevilla, L. Heim, A. Ho, T. Besiroglu, M. Hobbhahn, and P. Villalobos, “Compute Trends Across Three Eras of Machine Learning,” in 2022 International Joint Conference on Neural Networks (IJCNN), Jul. 2022, pp. 1–8. doi: 10.1109/IJCNN55064.2022.9891914.
[3]A. Shehabi et al., “United States Data Center Energy Usage Report,” LBNL--1005775, 1372902, Jun. 2016. doi: 10.2172/1372902.
[4]R. Carter, A. Cruden, and P. J. Hall, “Optimizing for Efficiency or Battery Life in a Battery/Supercapacitor Electric Vehicle,” IEEE Trans. Veh. Technol., vol. 61, no. 4, pp. 1526–1533, May 2012, doi: 10.1109/TVT.2012.2188551.
[5]C. Jin, X. Bai, C. Yang, W. Mao, and X. Xu, “A review of power consumption models of servers in data centers,” Appl. Energy, vol. 265, p. 114806, May 2020, doi: 10.1016/j.apenergy.2020.114806.
[6]J. Millán, P. Godignon, X. Perpiñà, A. Pérez-Tomás, and J. Rebollo, “A Survey of Wide Bandgap Power Semiconductor Devices,” IEEE Trans. Power Electron., vol. 29, no. 5, pp. 2155–2163, May 2014, doi: 10.1109/TPEL.2013.2268900.
[7]Y. Qin et al., “Thermal management and packaging of wide and ultra-wide bandgap power devices: a review and perspective,” J. Phys. Appl. Phys., vol. 56, no. 9, p. 093001, Feb. 2023, doi: 10.1088/1361-6463/acb4ff.
[8]S. K. Mazumder et al., “Overview of Wide/Ultrawide Bandgap Power Semiconductor Devices for Distributed Energy Resources,” IEEE J. Emerg. Sel. Top. Power Electron., vol. 11, no. 4, pp. 3957–3982, Aug. 2023, doi: 10.1109/JESTPE.2023.3277828.
[9]J. W. Milligan, S. Sheppard, W. Pribble, Y.-F. Wu, G. Muller, and J. W. Palmour, “SiC and GaN Wide Bandgap Device Technology Overview,” in 2007 IEEE Radar Conference, Apr. 2007, pp. 960–964. doi: 10.1109/RADAR.2007.374395.
[10]A. Hassan, A. Shakil Ahmed, and T. Sultana, “Determination of Characteristics and Performance Appraisal of GaN MESFET,” in 2018 International Conference on Innovations in Science, Engineering and Technology (ICISET), Oct. 2018, pp. 207–210. doi: 10.1109/ICISET.2018.8745661.
[11]K. Hoo Teo et al., “Emerging GaN technologies for power, RF, digital, and quantum computing applications: Recent advances and prospects,” J. Appl. Phys., vol. 130, no. 16, p. 160902, Oct. 2021, doi: 10.1063/5.0061555.
[12]Leroy S., “Silicon carbide: from gold rush to commodity?,” Yole Group. Accessed: Jun. 21, 2024. [Online]. Available: https://www.yolegroup.com/strategy-insights/silicon-carbide-from-gold-rush-to-commodity/
[13]A. M. S. Al-Bayati and M. A. Matin, “Behavior, Switching Losses, and Efficiency Enhancement Potentials of 1200 V SiC Power Devices for Hard-Switched Power Converters,” CPSS Trans. Power Electron. Appl., vol. 7, no. 2, pp. 113–129, Jun. 2022, doi: 10.24295/CPSSTPEA.2022.00011.
[14]J. P. Kozak et al., “Stability, Reliability, and Robustness of GaN Power Devices: A Review,” IEEE Trans. Power Electron., vol. 38, no. 7, pp. 8442–8471, Jul. 2023, doi: 10.1109/TPEL.2023.3266365.
[15]Shivani, D. Kaur, A. Ghosh, and M. Kumar, “A strategic review on gallium oxide based power electronics: Recent progress and future prospects,” Mater. Today Commun., vol. 33, p. 104244, Dec. 2022, doi: 10.1016/j.mtcomm.2022.104244.
[16]Y. Hao, “Gallium oxide: promise to provide more efficient life,” J. Semicond., vol. 40, no. 1, p. 010301, Jan. 2019, doi: 10.1088/1674-4926/40/1/010301.
[17]M. H. Wong, O. Bierwagen, R. J. Kaplar, and H. Umezawa, “Ultrawide-bandgap semiconductors: An overview,” J. Mater. Res., vol. 36, no. 23, pp. 4601–4615, Dec. 2021, doi: 10.1557/s43578-021-00458-1.
[18]M. Higashiwaki et al., “Recent progress in Ga2O3 power devices,” Semicond. Sci. Technol., vol. 31, no. 3, p. 034001, Jan. 2016, doi: 10.1088/0268-1242/31/3/034001.
[19]R. R. Sumathi, “Review—Status and Challenges in Hetero-epitaxial Growth Approach for Large Diameter AlN Single Crystalline Substrates,” ECS J. Solid State Sci. Technol., vol. 10, no. 3, p. 035001, Feb. 2021, doi: 10.1149/2162-8777/abe6f5.
[20]J. Yang, K. Liu, X. Chen, and D. Shen, “Recent advances in optoelectronic and microelectronic devices based on ultrawide-bandgap semiconductors,” Prog. Quantum Electron., vol. 83, p. 100397, May 2022, doi: 10.1016/j.pquantelec.2022.100397.
[21]T. P. Chow, I. Omura, M. Higashiwaki, H. Kawarada, and V. Pala, “Smart Power Devices and ICs Using GaAs and Wide and Extreme Bandgap Semiconductors,” IEEE Trans. Electron Devices, vol. 64, no. 3, pp. 856–873, Mar. 2017, doi: 10.1109/TED.2017.2653759.
[22]Y. Zhang, A. Dadgar, and T. Palacios, “Gallium nitride vertical power devices on foreign substrates: a review and outlook,” J. Phys. Appl. Phys., vol. 51, no. 27, p. 273001, Jun. 2018, doi: 10.1088/1361-6463/aac8aa.
[23]Y. Zhang, W. Yue, G. Zhang, G. Gao, F. Wang, and X. Huang, “Study of the power-load characteristics in a widely adapted driver circuit for several types power semiconductor device,” in 2021 IEEE 16th Conference on Industrial Electronics and Applications (ICIEA), Aug. 2021, pp. 843–848. doi: 10.1109/ICIEA51954.2021.9516149.
[24]S. Roy, A. Bhattacharyya, P. Ranga, H. Splawn, J. Leach, and S. Krishnamoorthy, “High-k Oxide Field-Plated Vertical (001) β-Ga2O3 Schottky Barrier Diode With Baliga’s Figure of Merit Over 1 GW/cm2,” IEEE Electron Device Lett., vol. 42, no. 8, pp. 1140–1143, Aug. 2021, doi: 10.1109/LED.2021.3089945.
[25]H. Liu et al., “10-kV Lateral β-Ga₂O₃ MESFETs With B Ion Implanted Planar Isolation,” IEEE Electron Device Lett., vol. 44, no. 7, pp. 1048–1051, Jul. 2023, doi: 10.1109/LED.2023.3279431.
[26]K. D. Chabak et al., “Recessed-Gate Enhancement-Mode \beta -Ga2O3 MOSFETs,” IEEE Electron Device Lett., vol. 39, no. 1, pp. 67–70, Jan. 2018, doi: 10.1109/LED.2017.2779867.
[27]A. K. Mondal, L. K. Ping, M. A. S. M. Haniff, R. Bahru, and M. A. Mohamed, “Recent Advancements in α-Ga2O3 Thin Film Growth for Power Semiconductor Devices via Mist CVD Method: A Comprehensive Review,” Cryst. Res. Technol., vol. 59, no. 3, p. 2300311, 2024, doi: 10.1002/crat.202300311.
[28]“製品サービス,” 最先端GaO®パワー半導体を手掛けるFLOSFIA（フロスフィア）. Accessed: Jun. 22, 2024. [Online]. Available: https://flosfia.com/products/
[29]Y. Gao et al., “Synthesis of n-type ZrO2 doped ε-Ga2O3 thin films by PLD and fabrication of Schottky diode,” J. Alloys Compd., vol. 900, p. 163120, Apr. 2022, doi: 10.1016/j.jallcom.2021.163120.
[30]S. Zhou et al., “A High-Performance ε-Ga2O3-Based Deep-Ultraviolet Photodetector Array for Solar-Blind Imaging,” Materials, vol. 16, no. 1, Art. no. 1, Jan. 2023, doi: 10.3390/ma16010295.
[31]J. Wang et al., “Pulsed X-Ray Detector Based on an Unintentionally-Doped High Resistivity ε-Ga₂O₃ Film,” IEEE Photonics Technol. Lett., vol. 35, no. 2, pp. 89–92, Jan. 2023, doi: 10.1109/LPT.2022.3224014.
[32]A. Parisini et al., “Study of SnO/ɛ-Ga2O3 p–n diodes in planar geometry,” J. Vac. Sci. Technol. A, vol. 40, no. 4, p. 042701, Jun. 2022, doi: 10.1116/6.0001857.
[33]W. Chen, H. Luo, Z. Chen, Y. Pei, G. Wang, and X. Lu, “First demonstration of hetero-epitaxial ε-Ga2O3 MOSFETs by MOCVD and a F-plasma surface doping,” Appl. Surf. Sci., vol. 603, p. 154440, Nov. 2022, doi: 10.1016/j.apsusc.2022.154440.
[34]S. Leone et al., “Epitaxial growth of GaN/Ga2O3 and Ga2O3/GaN heterostructures for novel high electron mobility transistors,” J. Cryst. Growth, vol. 534, p. 125511, Mar. 2020, doi: 10.1016/j.jcrysgro.2020.125511.
[35]Y. Zhuo, Z. Chen, W. Tu, X. Ma, Y. Pei, and G. Wang, “β-Ga2O3 versus ε-Ga2O3: Control of the crystal phase composition of gallium oxide thin film prepared by metal-organic chemical vapor deposition,” Appl. Surf. Sci., vol. 420, pp. 802–807, Oct. 2017, doi: 10.1016/j.apsusc.2017.05.241.
[36]X. Xia et al., “Hexagonal phase-pure wide band gap ε-Ga2O3 films grown on 6H-SiC substrates by metal organic chemical vapor deposition,” Appl. Phys. Lett., vol. 108, no. 20, p. 202103, May 2016, doi: 10.1063/1.4950867.
[37]X. Cao et al., “Crystalline properties of ε-Ga2O3 film grown on c-sapphire by MOCVD and solar-blind ultraviolet photodetector,” Mater. Sci. Semicond. Process., vol. 123, p. 105532, Mar. 2021, doi: 10.1016/j.mssp.2020.105532.
[38]P. Mazzolini et al., “Substrate-orientation dependence of β-Ga2O3 (100), (010), (001), and (2¯01) homoepitaxy by indium-mediated metal-exchange catalyzed molecular beam epitaxy (MEXCAT-MBE),” APL Mater., vol. 8, no. 1, p. 011107, Jan. 2020, doi: 10.1063/1.5135772.
[39]K. Sasaki, M. Higashiwaki, A. Kuramata, T. Masui, and S. Yamakoshi, “MBE grown Ga2O3 and its power device applications,” J. Cryst. Growth, vol. 378, pp. 591–595, Sep. 2013, doi: 10.1016/j.jcrysgro.2013.02.015.
[40]L. Dimitrocenko, G. Strikis, B. Polyakov, L. Bikse, S. Oras, and E. Butanovs, “The Effect of a Nucleation Layer on Morphology and Grain Size in MOCVD-Grown β-Ga2O3 Thin Films on C-Plane Sapphire,” Materials, vol. 15, no. 23, Art. no. 23, Jan. 2022, doi: 10.3390/ma15238362.
[41]C. W. Ahn, S. Park, M. S. Jeong, and E. K. Kim, “Defect dependence of electrical characteristics of β-Ga2O3 Schottky barrier diodes grown with hydride vapor phase epitaxy,” Mater. Sci. Semicond. Process., vol. 167, p. 107787, Nov. 2023, doi: 10.1016/j.mssp.2023.107787.
[42]S. Müller, H. von Wenckstern, D. Splith, F. Schmidt, and M. Grundmann, “Control of the conductivity of Si-doped β-Ga2O3 thin films via growth temperature and pressure,” Phys. Status Solidi A, vol. 211, no. 1, pp. 34–39, 2014, doi: 10.1002/pssa.201330025.
[43]Y. Xu et al., “Depletion-Mode β-Ga2O3 MOSFETs Grown by Nonvacuum, Cost-Effective Mist-CVD Method on Fe-Doped GaN Substrates,” IEEE Trans. Electron Devices, vol. 69, no. 3, pp. 1196–1199, Mar. 2022, doi: 10.1109/TED.2022.3143472.
[44]J. Tauc, “Optical properties and electronic structure of amorphous Ge and Si,” Mater. Res. Bull., vol. 3, no. 1, pp. 37–46, Jan. 1968, doi: 10.1016/0025-5408(68)90023-8.
[45]M. Tsuno, M. Suga, M. Tanaka, K. Shibahara, M. Miura-Mattausch, and M. Hirose, “Physically-based threshold voltage determination for MOSFET’s of all gate lengths,” IEEE Trans. Electron Devices, vol. 46, no. 7, pp. 1429–1434, Jul. 1999, doi: 10.1109/16.772487.
[46]Y. Lv et al., “Influence of gate recess on the electronic characteristics of β-Ga2O3 MOSFETs,” Superlattices Microstruct., vol. 117, pp. 132–136, May 2018, doi: 10.1016/j.spmi.2018.03.013.
[47]G. Atmaca and H.-Y. Cha, “Normally-off recessed gate β-Ga2O3 MOSHFETs with a modulation-doped heterostructure back-barrier,” Phys. Scr., vol. 99, no. 3, p. 035901, Feb. 2024, doi: 10.1088/1402-4896/ad213f.
[48]C. Joishi et al., “Deep-Recessed β-Ga₂O₃ Delta-Doped Field-Effect Transistors With In Situ Epitaxial Passivation,” IEEE Trans. Electron Devices, vol. 67, no. 11, pp. 4813–4819, Jan. 2020, doi: 10.1109/TED.2020.3023679.
[49]V. Khandelwal et al., “Monolithic β-Ga2O3 NMOS IC based on heteroepitaxial E-mode MOSFETs,” Appl. Phys. Lett., vol. 122, no. 14, p. 143502, Apr. 2023, doi: 10.1063/5.0143315.