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【会员论文】复旦大学方志来教授等：全氧化镓薄膜同质p-n结
日期：2024-04-03阅读：191
制备p-n结以及探索其物理机制在发展各种功能器件和推进其实际应用中起到关键作用。超宽禁带半导体在制备高压高频器件上有着巨大的应用潜力，但是氧化镓p型掺杂困难，从而限制了氧化镓同质p-n结的制备，阻碍了全氧化镓基双极型器件的发展。
近日，复旦大学方志来教授等人在Science China Materials发表研究论文，通过一种先进的相转变生长技术结合溅射镀膜的方法，成功制备了n型锡掺杂β相氧化镓/p型氮掺杂β相氧化镓薄膜。
本文要点
1) 成功制作了全氧化镓单边突变同质p-n结二极管，并且详细分析了器件机理。
2) 该二极管实现了4 × 104的整流比、在40 V下9.18 mΩ cm2的低导通电阻、4.41V的内建电势和1.78的理想因子, 并在交流电压下表现出无过冲的整流特性以及长期稳定性.
本工作为氧化镓同质p-n结初窥门径，为氧化镓同质双极型器件奠定了基础，为高压高功率器件的应用开创了道路。
Figure 1.(a) HRTEM images of Sample SP obtained at different locations of the β-Ga2O3/GaN interface. (b) Formation energy versus chemical potential of O atoms ΔμO. (c) Transition level of the NO(III)acceptor.
Figure 2.(a) Hall voltage versus magnetic field curve from van der Pauw Hall effect measurement of the N-doped β-Ga2O3thin films. (b) Drain-source current (IDS) versus gate-source voltage (VGS) characteristic curve of the N-doped β-Ga2O3films top-gate FET in linear and log scale at a drain-source voltage (VDS) of 20 V. (c) XRD spectrum of the Sn-doped β-Ga2O3/N-doped β-Ga2O3films on the sapphire substrate. (d) SIMS depth profile of the Sn-doped β-Ga2O3/N-doped β-Ga2O3films showing the concentrations of Sn and N. (e) SIMS elemental mappings of Ga (brown), O (red), Al (green), Sn (pink), N (blue) components, and the layer structure of the β-Ga2O3film. (f) Hall voltage versus magnetic field curve from van der Pauw Hall effect measurement of the Sn-doped β-Ga2O3thin films. (g) IDSversus VGScharacteristic curve of the Sn-doped β-Ga2O3back-gate FET in linear and log scale at a VGSof 20 V.
Figure 3.(a) Schematic of the n-type Sn-doped β-Ga2O3/p-type N-doped β-Ga2O3homojunction diode (Vpn). (b) I–V and (c) C–V curves with the applied voltage Vnnon Pad 1/2 and the applied voltage Vppon Pad 3/4. (d) Forward current density and Ron,spversus applied voltage curve. (e) Current density versus voltage curves of the β-Ga2O3p-n homojunction diode measured on the first month and the seventh month. (f) Rectified output current using the β-Ga2O3diode by applying an AC square wave.
Figure 4.Schematic band diagrams of (a) p-type and n-type β-Ga2O3, and (b) β-Ga2O3p-n homojunction. (c) Schematic band diagrams and internal mechanisms of β-Ga2O3p-n homojunction under different biases.
