AI 中文总结
研究通过低压化学气相沉积在(010)β-Ga₂O₃衬底生长掺锗同质外延薄膜，实现可控n型掺杂，薄膜有良好结构与电学特性，所制肖特基二极管性能佳，证明该方法能保持高结构和电子质量，可用于未来高压电力电子器件。
AI 中文摘要
在本工作中，采用低压化学气相沉积（LPCVD）在原生(010)β-Ga₂O₃衬底上生长掺锗β-Ga₂O₃同质外延薄膜。实现了可控的n型掺杂，室温载流子浓度范围为7.4×10¹⁷至2.57×10¹⁸ cm⁻³，相应电子迁移率为105 - 62 cm²/V·s。薄膜表面形貌光滑，均方根粗糙度值为2.94 - 3.97 nm，X射线衍射、拉曼光谱和X射线光电子能谱证实为相纯β-Ga₂O₃，具有优异晶体质量和近化学计量组成。对室温载流子浓度为7.4×10¹⁷ cm⁻³、迁移率为105 cm²/V·s的薄膜进行变温霍尔测量，在116 K时峰值电子迁移率为234 cm²/V·s，电荷中性和输运模型揭示了一个激活能为14 meV的主导浅施主能级，证实了锗施主的有效电激活。使用掺锗漂移层制备的垂直Ni/β-Ga₂O₃肖特基势垒二极管表现出良好的整流行为，开启电压为0.74 V，理想因子为1.32，肖特基势垒高度为1.02 eV，比导通电阻为2.49 mΩ·cm²。电容-电压测量得到净施主浓度为7.7×10¹⁷ cm⁻³，肖特基势垒高度为1.13 eV，与霍尔测量和电流-电压测量结果吻合良好。这些结果表明LPCVD能够实现可控的锗掺杂，同时保持高结构和电子质量，确立了LPCVD生长的掺锗β-Ga₂O₃作为未来高压电力电子器件的有前途平台。
英文摘要
In this work, Ge-doped $β$-Ga$_2$O$_3$ homoepitaxial films were grown on native (010) $β$-Ga$_2$O$_3$ substrates using low-pressure chemical vapor deposition (LPCVD). Controlled $n$-type doping was achieved with room-temperature carrier concentrations ranging from $7.4\times10^{17}$ to $2.57\times10^{18}\ \mathrm{cm}^{-3}$ and corresponding electron mobilities of 105-62 cm$^2$/V$\cdot$s. The films exhibited smooth surface morphology with RMS roughness values of 2.94-3.97 nm, while X-ray diffraction, Raman spectroscopy, and X-ray photoelectron spectroscopy confirmed phase-pure $β$-Ga$_2$O$_3$ with excellent crystalline quality and near-stoichiometric composition. Temperature-dependent Hall measurements on the film with a room-temperature carrier concentration of $7.4\times10^{17}\ \mathrm{cm}^{-3}$ and mobility of 105 cm$^2$/V$\cdot$s yielded a peak electron mobility of 234 cm$^2$/V$\cdot$s at 116 K, while charge-neutrality and transport modeling revealed a dominant shallow donor level with an activation energy of 14 meV, confirming efficient electrical activation of Ge donors. Vertical Ni/$β$-Ga$_2$O$_3$ Schottky barrier diodes fabricated using the Ge-doped drift layer exhibited good rectifying behavior with a turn-on voltage of 0.74 V, an ideality factor of 1.32, a Schottky barrier height of 1.02 eV, and a specific on-resistance of 2.49 m$Ω\cdot$cm$^2$. Capacitance-voltage measurements yielded a net donor concentration of $7.7\times10^{17}\ \mathrm{cm}^{-3}$ and a Schottky barrier height of 1.13 eV, in good agreement with Hall and current-voltage measurements. These results demonstrate that LPCVD enables controllable Ge doping while maintaining high structural and electronic quality, establishing LPCVD-grown Ge-doped $β$-Ga$_2$O$_3$ as a promising platform for future high-voltage power electronic devices.
