Simulation Study on Electrical Performance of a New Composite Terminal Gallium Oxide Schottky Diode

doi:10.16553/j.cnki.issn1000-985x.2024.0179

Abstract

Abstract: As a new generation of wide bandgap semiconductor, gallium oxide has a larger bandgap width(4.4~4.8 eV) and higher breakdown field strength (8 MV/cm), making it an ideal material for fabricating high voltage, high frequency, and high power electronic devices. However, due to the edge concentration effect of the terminal electric field of gallium oxide Schottky diodes, the device fails due to premature breakdown, thus limiting the application of gallium oxide. A new type of composite terminal is designed in this paper, which is formed by combining a high-resistance region that can alleviate the edge concentration effect of the electric field and an electron barrier layer that suppresses reverse leakage. The simulation results show that the peak electric field near the edge of the device electrode that introduces the high-resistance region terminal structure drops from 3.650 MV/cm to 0.246 MV/cm, which can effectively alleviate the edge concentration effect of the electrode electric field. When the Mg ion implantation concentration in the high-resistance region is 10¹⁹ cm^-3, the breakdown voltage increases from 725 V to 2 115 V, the Baliga figure of merit increases from 0.060 GW/cm² to 0.247 GW/cm², and the critical breakdown field strength increases by 50.7% (from 3.650 MV/cm to 5.500 MV/cm); at the same time, the introduction of the electronic barrier layer AlN greatly reduces the reverse leakage current of the device, and the reverse breakdown voltage increases to 2 690 V, which is beneficial to the new composite terminal. The new composite structure can not only effectively suppress the reverse leakage current of the device but also effectively increase the reverse breakdown voltage of the device. This research lays a theoretical foundation for the development of high voltage resistant, low reverse leakage current gallium oxide Schottky diodes.

Key words: β-Ga₂O₃, Schottky diode, reverse leakage current, breakdown voltage, composite terminal

CLC Number:

QU Minmin, YU Jiangang, LI Ziwei, LI Wangwang, LEI Cheng, LI Tengteng, LI Fengchao, LIANG Ting, JIA Renxu. Simulation Study on Electrical Performance of a New Composite Terminal Gallium Oxide Schottky Diode[J]. Journal of Synthetic Crystals, 2025, 54(2): 348-357.

References

[1] DONG H, XUE H W, HE Q M, et al. Progress of power field effect transistor based on ultra-wide bandgap Ga₂O₃ semiconductor material[J]. Journal of Semiconductors, 2019, 40(1): 011802.
[2] PEARTON S J, YANG J C, CARY P H, et al. A review of Ga₂O₃ materials, processing, and devices[J]. Applied Physics Reviews, 2018, 5(1): 011301.
[3] LIU Z, LI P G, ZHI Y S, et al. Review of gallium oxide based field-effect transistors and Schottky barrier diodes[J]. Chinese Physics B, 2019, 28(1): 017105.
[4] MASTRO M A, KURAMATA A, CALKINS J, et al. Perspective—opportunities and future directions for Ga₂O₃[J]. ECS Journal of Solid State Science and Technology, 2017, 6(5): P356-P359.
[5] 张晋, 胡壮壮, 穆文祥, 等. 高质量氧化镓单晶及肖特基二极管的制备[J]. 人工晶体学报, 2020, 49(11): 2194-2199.
ZHANG J, HU Z Z, MU W X, et al. High quality β-Ga₂O₃ single crystal and fabrication of Schottky diode[J]. Journal of Synthetic Crystals, 2020, 49(11): 2194-2199 (in Chinese).
[6] 麻尧斌, 石健, 赵聪鹏, 等. 全球氧化镓产业发展概况及对我国的启示[J]. 中国集成电路, 2023, 32(7): 12-16.
MA Y B, SHI J, ZHAO C P, et al. Overview of global gallium oxide industry development and its enlightenment for China[J]. China Integrated Circuit, 2023, 32(7): 12-16 (in Chinese).
[7] 汪海波, 万丽娟, 樊敏, 等. 势垒可调的氧化镓肖特基二极管[J]. 物理学报, 2022, 71(3): 037301.
WANG H B, WAN L J, FAN M, et al. Barrier-tunable gallium oxide Schottky diode[J]. Acta Physica Sinica, 2022, 71(3): 037301(in Chinese).
[8] LI L, LIAO F, HU X T. The possibility of N-P codoping to realize P type β-Ga₂O₃[J]. Superlattices and Microstructures, 2020, 141: 106502.
[9] CHOI J H, CHO C H, CHA H Y. Design consideration of high voltage Ga₂O₃ vertical Schottky barrier diode with field plate[J]. Results in Physics, 2018, 9: 1170-1171.
[10] HU T C, WANG Z P, SUN N, et al. A self-aligned Ga₂O₃ heterojunction barrier Schottky power diode[J]. Applied Physics Reviews, 2023, 123(1): 013507.
[11] HU Z Z, ZHAO C Y, FENG Q, et al. The investigation of β-Ga₂O₃ Schottky diode with floating field ring termination and the interface states[J]. ECS Journal of Solid State Science and Technology, 2020, 9(2): 025001.
[12] JANG C H, ATMACA G, CHA H Y. Normally-off β-Ga₂O₃ MOSFET with an epitaxial drift layer[J]. Micromachines, 2022, 13(8): 1185.
[13] JIAO T, CHEN W, LI Z D, et al. Fabrication of Ga₂O₃ Schottky barrier diode and heterojunction diode by MOCVD[J]. Materials, 2022, 15(23): 8280.
[14] ALLEN N, XIAO M, YAN X D, et al. Vertical Ga₂O₃ Schottky barrier diodes with small-angle beveled field plates: a Baliga’s figure-of-merit of 0.6 GW/cm²[J]. IEEE Electron Device Letters, 2019, 40(9): 1399-1402.
[15] WANG Y G, LV Y J, LONG S B, et al. High-voltage β-Ga₂O₃ vertical Schottky barrier diode with thermally-oxidized termination[J]. IEEE Electron Device Letters, 2020, 41(1): 131-134.
[16] DONG P F, ZHANG J C, YAN Q L, et al. 6 kV/3.4 mΩ·cm² vertical β-Ga₂O₃ Schottky barrier diode with BV²/R_{on, sp} performance exceeding 1-D unipolar limit of Gan and SiC[J]. IEEE Electron Device Letters, 2022, 43(5): 765-768.
[17] LI J S, WAN H H, CHIANG C C, et al. NiO/Ga₂O₃ Vertical Rectifiers of 7 kV and 1 mm² with 5.5 A Forward Conduction Current[J]. Crystals, 2023, 13(12): 1624.
[18] ZHOU H, YAN Q L, ZHANG J C, et al. High-performance vertical β-Ga₂O₃ Schottky barrier diode with implanted edge termination[J]. IEEE Electron Device Letters, 2019, 40(11): 1788-1791.
[19] YAO S H, YANG K M, YANG L L, et al. Investigation on β-Ga₂O₃-based Schottky barrier diode with floating metal rings[J]. Crystals, 2023, 13(4): 666.
[20] CHEN H, WANG H Y, SHENG K. Vertical β-Ga₂O₃, Schottky barrier diodes with field plate assisted negative beveled termination and positive beveled termination[J]. IEEE Electron Device Letters, 2023, 44(1): 21-24.
[21] MAEDA T, NARITA T, UEDA H, et al. Design and fabrication of GaN p-n junction diodes with negative beveled-mesa termination[J]. IEEE Electron Device Letters, 2019, 40(6): 941-944.
[22] 龙泽, 夏晓川, 石建军, 等. 基于机械剥离 β-Ga₂O₃的Ni/Au垂直结构肖特基器件的温度特性[J]. 物理学报, 2020, 69(13): 138501.
LONG Z, XIA X C, SHI J J, et al. Temperature dependent characteristics of Ni/Au vertical Schottky diode based on mechanically exfoliated β-Ga₂O₃ single crystal[J]. Acta Physica Sinica, 2020, 69(13): 138501 (in Chinese).
[23] ZHOU X, LI M, ZHANG J Z, et al. High quality P-type Mg-doped β-Ga₂O_3-δ films for solar-blind photodetectors[J]. IEEE Electron Device Letters, 2022, 43(4): 580-583.
[24] 李京波, 盖艳琴, 康俊, 等. 新型半导体深能级掺杂机制研究[J]. 科学通报, 2018, 63(4): 365-370.
LI J B, GAI Y Q, KANG J, et al. Doping mechanism in novel semiconductor materials[J]. Chinese Science Bulletin, 2018, 63(4): 365-370 (in Chinese).
[25] NANDI A, RANA K S, BAG A. Design and analysis of P-GaN/N-Ga₂O₃ based junction barrier Schottky diodes[J]. IEEE Transactions on Electron Devices, 2021, 68(12): 6052-6058.
[26] DAVIS B E, STRANDWITZ N C. Dependence of the metal-insulator-semiconductor Schottky barrier height on insulator composition[J]. ACS Applied Electronic Materials, 2024, 6(2): 770-776.
[27] JAMWAL N S, KIANI A. Gallium oxide nanostructures: a review of synthesis, properties and applications[J]. Nanomaterials, 2022, 12(12): 2061.
[28] 郭亮良, 栾苏珍, 张弘鹏, 等. 垂直增强型氧化镓MOSFET器件自热效应研究[J]. 中国科学: 物理学力学天文学, 2022, 52(9): 75-84.
GUO L L, LUAN S Z, ZHANG H P, et al. Study on self heating effect of enhancement-mode Ga₂O₃ vertical MOSFET[J]. Scientia Sinica (Physica, Mechanica & Astronomica), 2022, 52(9): 75-84 (in Chinese).
[29] VAN OVERSTRAETEN R, MAN H D. Measurement of the ionization rates in diffused silicon p-n junctions[J]. Solid State Electronics, 1970, 13(5): 583-608.
[30] STEFANAKIS D, MAKRIS N, ZEKENTES K, et al. Comparison of impact ionization models for 4H-SiC along the direction, through breakdown voltage simulations at room temperature[J]. IEEE Transactions on Electron Devices, 2021, 68(5): 2582-2586.
[31] 王威礼, 王德煌, 让庆澜, 等. GaAs∶ Cr中深能级俘获效应对电导的影响[J]. 北京大学学报(自然科学版), 1991, 27(5): 599-607.
WANG W L, WANG D H, RANG Q L, et al. GaAs∶Cr deep level trapping effect on conductivity[J]. Acta Scicentiarum Naturalum Universitis Pekinesis, 1991, 27(5): 599-607 (in Chinese).
[32] KIM M Y, BYUN D W, LEE G H, et al. Schottky barrier heights and electronic transport in Ga₂O₃ Schottky diodes[J]. Materials Research Express, 2023, 10(7): 075902.
[33] KIM H. Vertical Schottky contacts to bulk GaN single crystals and current transport mechanisms: a review[J]. Journal of Electronic Materials, 2021, 50(12): 6688-6707.
[34] BALIGA B J. Fundamentals of power semiconductor devices[M]. Springer Science & Business Media, 2010.
[35] MASE A, KUBO T, MIYOSHI M, et al. Improved reverse-bias breakdown behavior in fully-vertical GaN-on-Si Schottky barrier diodes with a thin AlN layer within the GaN drift layer[J]. Semiconductor Science and Technology, 2023, 38(9): 095005.