沟槽结构 $ \beta-Ga_{2}O_{3} $ SBD 的设计与仿真

在肖特基势垒二极管(Schottky barrier diode, SBD)漂移层表面刻蚀沟槽形成金属-绝缘体-半导体(metal-insulator-semiconductor, MIS)结构, 抑制镜像力效应并减小器件的反向漏电流, 是提升器件反向击穿特性的有效途径。为优化沟槽结构 $ \beta-Ga_{2}O_{3} $ SBD 的结构参数, 文章利用 Silvaco Atlas 软件仿真不同台面宽度和沟槽深度对器件性能的影响。结果表明, 参数优化后(台面宽度 1.0 $ \mu $m, 沟槽深度 0.5 $ \mu $m)的沟槽结构 $ \beta-Ga_{2}O_{3} $ SBD 开启电压为 0.6 V、比导通电阻为 1.69 m $ \Omega \cdot $ cm $ ^{2} $、击穿电压为 1416 V、功率品质因数为 1.19 GW/cm $ ^{2} $, 实现了兼具低开启电压和高击穿电压的良好器件性能。与基础结构 SBD 和场板结构 SBD 相比, 优化后的器件性能得到显著提升。

The metal-insulator-semiconductor (MIS) structure formed by trenching the drift layer of Schottky barrier diode (SBD) can restrict the image force and reduce the reverse leakage current, which has proved to be effective in improving the reverse breakdown characteristics of the device. To optimize the structure parameters of trenched $ \beta $-Ga $ _{2} $O $ _{3} $ SBD, the effect of mesa width and trench depth on the device performance was researched by simulation using Silvaco Atlas. Results revealed that the trenched $ \beta $-Ga $ _{2} $O $ _{3} $ SBD with the mesa width of 1.0 $ \mu $m and trench depth of 0.5 $ \mu $m presented the turn-on voltage of 0.6 V, specific on-resistance of 1.69 m $ \Omega $ $ \cdot $ cm $ ^{2} $, breakdown voltage of 1416 V and power figure of merit of 1.19 GW/cm $ ^{2} $, showing merits of both low turn-on voltage and high breakdown voltage. The device performance was remarkably improved when compared to that of the regular SBD and field-plated SBD.