Wang An-Feng, Ma Hong-Ping, Huang Qi-Min, Gu Lin, Shen Yi, Ding Chengxi, Liu Yang-Chao, Xu Kun, Zhucheng Li, Zhang Li, Zhang Xiaodong, Zhang Qing-Chun
Institute of Wide Bandgap Semiconductors and Future Lighting, Academy for Engineering & Technology, Fudan University, Shanghai 200433, China.
Shanghai Research Center for Silicon Carbide Power Devices Engineering & Technology, Fudan University, Shanghai 200433, China.
ACS Appl Mater Interfaces. 2025 May 7;17(18):27517-27529. doi: 10.1021/acsami.5c04203. Epub 2025 Apr 28.
β-phase gallium oxide (β-GaO)/aluminum nitride (AlN) heterojunctions hold significant potential for high-power and microwave device applications. In this study, we systematically investigated the properties of the β-GaO/AlN heterostructure grown via metal-organic chemical vapor deposition (MOCVD). High-resolution X-ray diffraction (HRXRD) and Raman spectroscopy revealed the crystal structures and demonstrated the high-crystalline quality of both films. Atomic force microscopy (AFM) scans displayed a smooth β-GaO surface with a root-mean-square (RMS) roughness of 3.6 nm. Scanning electron microscopy (SEM) images showed a flat surface with distinct heterostructure boundaries. Elemental distributions across the interface were mapped by using energy-dispersive spectroscopy (EDS). X-ray photoelectron spectroscopy (XPS) analysis characterized the chemical components of the sample and confirmed a type-II band alignment in the heterojunction, which facilitates electron accumulation. Furthermore, the thermal conductivity of β-GaO was measured at 4.2 W/(m·K), and the thermal boundary conductivity at the β-GaO/AlN interface was determined to be 118.6 MW/(m·K) using the time-domain thermoreflectance (TDTR) method. Temperature-dependent electrical performance of the β-GaO/AlN SBD, including a low turn-on voltage of 0.1 V, ideality factor of 4.22, modified Richardson constant of 48.5 A/cm K, and high breakdown voltage of 1260 V, was obtained. All of these values are competitive among β-GaO-based heterostructures. The findings highlight the excellent interface quality, superior heat dissipation capability, and decent SBD performance of the β-GaO/AlN integration, offering a promising platform for developing β-GaO-based power devices capable of operating at high temperatures.
β相氧化镓（β-GaO）/氮化铝（AlN）异质结在高功率和微波器件应用方面具有巨大潜力。在本研究中，我们系统地研究了通过金属有机化学气相沉积（MOCVD）生长的β-GaO/AlN异质结构的特性。高分辨率X射线衍射（HRXRD）和拉曼光谱揭示了晶体结构，并证明了两种薄膜的高结晶质量。原子力显微镜（AFM）扫描显示β-GaO表面光滑，均方根（RMS）粗糙度为3.6 nm。扫描电子显微镜（SEM）图像显示表面平整，异质结构边界清晰。使用能量色散光谱（EDS）绘制了界面处的元素分布。X射线光电子能谱（XPS）分析表征了样品的化学成分，并证实了异质结中的II型能带排列，这有利于电子积累。此外，测量得到β-GaO的热导率为4.2 W/（m·K），使用时域热反射（TDTR）方法确定β-GaO/AlN界面处的热边界导率为118.6 MW/（m·K）。获得了β-GaO/AlN肖特基势垒二极管（SBD）随温度变化的电学性能，包括低开启电压0.1 V、理想因子4.22、修正理查森常数48.5 A/cm²K以及高击穿电压1260 V。所有这些值在基于β-GaO的异质结构中具有竞争力。这些发现突出了β-GaO/AlN集成优异的界面质量、卓越的散热能力和良好的SBD性能，为开发能够在高温下工作的基于β-GaO的功率器件提供了一个有前景的平台。
