基于Ga2O3掺Sn沟道与掺Fe栅层的FET相关技术研究

With high breakdown voltage and low energy loss, Ga2O3 is considered as the potential material for power transistor application. However, the performance of Ga2O3 based devices still non-ideal at present. The essential scientific and technical obstacles are the controllable growth of high-quality doped Ga2O3 thin film channel and lattice-matched insulated gate material with tunable characteristic properties. Therefore, it is of great scientific significance and application value to study the doping process of Ga2O3 channel materials as well as the homogeneous growth of Ga2O3 insulation gate materials. In this proposed project, in order to optimize the performance parameters of the transistor, we study the influence of electronic structure, crystal transition, defects, doping, and other factors on the electrical properties of Ga2O3 by theoretical calculation. The controllable carrier concentration in the channel material could be experimentally obtained by high quality Sn doped Ga2O3 film, whereas the insulating gate material could be obtained by high quality Fe doped Ga2O3 film. Moreover, the prototype transistor will be designed and optimized to improve the performance of the device. It is expected that this project will shed light the development of new generation power transistor based on Ga2O3 material.

具有高击穿场强和低能量损耗的Ga2O3材料在功率晶体管方面具有良好的应用前景。目前高质量掺杂Ga2O3薄膜沟道以及与Ga2O3晶格匹配的高效绝缘栅材料的可控生长与性能调控是面临的重要科学与技术障碍，使得Ga2O3基功率晶体管的发展还处于较低水平，Ga2O3材料的性能优势尚未体现出来。因此，系统地研究Ga2O3薄膜沟道材料的掺杂工艺、探索Ga2O3同质绝缘栅制备技术具有重要科学的意义和应用价值。本项目拟通过理论计算研究Ga2O3电子结构、晶型转变、晶体缺陷、元素掺杂等多种因素对Ga2O3电学性能的影响，优化影响晶体管性能的材料电学性能参数。通过实验实现高质量Sn掺杂Ga2O3沟道薄膜载流子浓度可控生长技术及Fe掺杂的高质量Ga2O3绝缘栅层的制备工艺。设计、制备出晶体管器件原型优化器件结构，提高器件的性能。项目研究为Ga2O3基的新型功率晶体管的研发及其应用提供理论与技术支撑。

Ga2O3作为超宽禁带半导体材料，其带隙为4.9 eV，理论击穿场强高达8 MV/cm，在高能物理、深紫外探测和功率电子器件等领域应用广泛。然而，受限于掺杂工艺的开发和光电物性的研究，Ga2O3优异的材料性能未能充分展现。特别是高质量掺杂Ga2O3沟道层和绝缘层可控生长技术的滞后，限制了Ga2O3功率晶体管的发展。通过合适施主或受主掺杂，不仅可以改变氧化镓的晶体结构，还能调控其载流子浓度，获得高绝缘或高导电性能。厘清元素掺杂与氧化镓基础物性之间的关联，是我们构建高性能光电和功率器件的基础。本项目基于获得高质量Ga2O3基场效应晶体管的目标，开展了一系统掺杂调控的外延生长研究，取得了如下成果：（1）基于脉冲激光沉积技术，通过Sn掺杂Ga2O3外延薄膜的工艺探索，获得了具备优异光电性能的Sn:Ga2O3外延薄膜；（2）基于分子束外延技术，制备了高绝缘Fe掺杂Ga2O3外延薄膜，并研究了其光电和磁学性能；（3）基于金属有机物化学气相沉积方法，制备了Si掺杂的高质量Ga2O3外延薄膜，并基于Si:Ga2O3薄膜制备了金属半导体场效应晶体管（MESFET），研究了其光电性能；（4）基于不同元素掺杂、不同晶相的Ga2O3薄膜，制备了具备自供电性能的肖特基和异质结光电探测器。通过本项目，我们掌握了高效的氧化镓外延薄膜掺杂生长技术，厘清了Sn/Fe/Si等元素掺杂对氧化镓基础光电性能的影响，构建了常关型氧化镓基MESFET器件，并拓展了Ga2O3深紫外日盲探测器在节能光电子领域的应用。同时，我们通过项目开展取得了丰硕的科研成果，共发表SCI论文41篇，申请中国发明专利6篇，培养研究生16名（其中8名博士，8名硕士），并在国内外相关学术会议做报告13次。