AI 中文总结
本研究开发了一种基于选择性MOCVD再生长n⁺接触层的无注入欧姆接触技术，结合氮注入电流阻挡层，制备出高性能增强型垂直β-Ga₂O₃ U型沟槽MOSFET，器件展现出优异的电学特性。
AI 中文摘要
本研究针对增强型垂直β-Ga₂O₃ U型沟槽MOSFET，展示了一种基于选择性MOCVD再生长硅掺杂n⁺层的无注入欧姆接触技术。该再生长n⁺接触结构无需采用基于注入的欧姆接触形成工艺，同时保持了优异的电学特性。研究采用多能量氮离子注入电流阻挡层（CBL），随后在氮气氛围中进行1100℃、30分钟的激活退火，以实现常关（normally-OFF）工作模式。传输线模型测量得到的比接触电阻率低至2.65×10⁻⁷Ω·cm²。所制备的器件展现出约5V的阈值电压、1.15×10⁶的开/关电流比、158A/cm²的峰值电流密度，以及120.9mΩ·cm²的比导通电阻。在V_GS=0V条件下，三端关态击穿电压达到920至980V，多指MOSFET的电流可扩展至0.25A。这些结果表明，选择性MOCVD再生长n⁺接触层为实现高性能垂直β-Ga₂O₃功率MOSFET提供了一种极具前景的无注入方法。
英文摘要
In this work, an implantation-free ohmic contact technology based on selectively MOCVD-regrown Si-doped n$^+$ layers is demonstrated for enhancement-mode vertical $β$-Ga$_2$O$_3$ U-trench MOSFETs. The regrown n$^+$ contact structure eliminates the need for implantation-based ohmic contact formation while maintaining excellent electrical characteristics. A multi-energy nitrogen-ion-implanted current blocking layer (CBL) followed by 1100~$^\circ$C activation annealing in N$_2$ ambient for 30 min was employed to achieve normally-OFF operation. Transmission line model measurements yielded a low specific contact resistivity of $2.65 \times 10^{-7}~Ω\cdot$cm$^2$. The fabricated devices exhibited a threshold voltage of approximately 5~V, an ON/OFF current ratio of $1.15\times10^{6}$, a peak current density of 158A/cm$^2$, and a specific ON-resistance of 120.9~m$Ω\cdot$cm$^2$. Three-terminal OFF-state breakdown voltages ranging from 920 to 980~V were achieved at $V_{GS}=0$~V. Multi-finger MOSFETs show current scaling to 0.25 A. These results demonstrate that selectively MOCVD-regrown n$^+$ contact layers provide a promising implantation-free approach for realizing high-performance vertical $β$-Ga$_2$O$_3$ power MOSFETs.
