We report high-performance homojunction GaN avalanche photodiodes (APDs) grown on a low-defect GaN substrate and fabricated with an ion-implantation isolation method. High-quality p-i-n GaN layers were grown using metalorganic chemical vapor deposition (MOCVD), and an effective device isolation method using optimized nitrogen ion implantation was developed to provide significant leakage current suppression on the etched mesa sidewalls. Fabricated GaN APDs showed an ultralow dark current density < 10 ⁻⁹ A/cm ² up to 50% of the avalanching breakdown voltage region and achieved a photocurrent gain of >106 at a reverse bias of 71.5 V under deep-ultraviolet (DUV) illumination at $\lambda =280$ nm. A further temperature-dependent study of the dark current indicated that a trap-assisted tunneling process predominates the leakage current component that also contributes to the carrier multiplication process near the avalanching breakdown.

中文翻译：

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离子注入隔离法有效降低GaN紫外雪崩光电二极管的漏电流

我们报告了高性能同质结GaN雪崩光电二极管（APDs）生长在低缺陷GaN衬底上并用离子注入隔离法制造的情况。使用金属有机化学气相沉积（MOCVD）生长高质量的pin GaN层，并开发了一种使用优化的氮离子注入的有效器件隔离方法，以在蚀刻的台面侧壁上提供显着的漏电流抑制。制备的GaN APD在雪崩击穿电压区域的50％处显示<10 ^-9 A / cm ²的超低暗电流密度， 并在深紫外（DUV）照明下以71.5 V的反向偏置实现了> 106的光电流增益在 $ \ lambda = 280 $ 纳米 暗电流的进一步温度相关研究表明，陷阱辅助隧穿过程占主导地位的漏电流分量，也有助于雪崩击穿附近的载流子倍增过程。