Dark current behaviors of the $2.6~\mu \text{m}$ cutoff wavelength In_0.83Ga_0.17As photodetectors are investigated as a function of the mesa etching depth. The total dark current monotonically declines from $2.0\times 10^{-6}$ A/cm² to $8.3\times 10^{-7}$ A/cm² at 180 K and −10 mV as the mesa etching depth decreases from 2.6 to $0.9~\mu \text{m}$ . Meanwhile, an order of magnitude lower surface leakage current from 4.56 to 0.47 nA/cm, and a narrower statistical distribution are observed simultaneously. Moreover, the 300 K peak detectivity and quantum efficiency increase from $2.6\times 10^{11}$ to $5.4\times 10^{11}$ cmHz^1/2/W and from 67.1% to 71.2%, respectively, as the mesa etching depth decreases from 2.6 to $0.9~\mu \text{m}$ , benefit from the lateral carrier collection effect. These results suggest shallow mesa structures are indispensable towards surface leakage free In_0.83Ga_0.17As photodetectors.

中文翻译：

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2.6 μm In0.83Ga0.17As 光电探测器的表面泄漏行为与台面蚀刻深度的函数关系

暗电流行为 $2.6~\mu \text{m}$ 截止波长 In _0.83 Ga _0.17 As 光电探测器被研究为台面蚀刻深度的函数。总暗电流从 $2.0\乘以 10^{-6}$ A/cm ²至 $8.3\乘以 10^{-7}$ A/cm ²在 180 K 和 -10 mV 随着台面蚀刻深度从 2.6 减小到 $0.9~\mu \text{m}$ . 同时，同时观察到从 4.56 到 0.47 nA/cm 低一个数量级的表面漏电流，以及更窄的统计分布。此外，300 K 峰值检测率和量子效率从 $2.6\乘以 10^{11}$ 至 $5.4\乘以 10^{11}$ cmHz ^1/2 /W 和分别从 67.1% 到 71.2%，随着台面蚀刻深度从 2.6 减小到 $0.9~\mu \text{m}$ ，受益于横向载流子收集效应。这些结果表明浅台面结构对于无表面泄漏的 In _0.83 Ga _0.17 As 光电探测器是必不可少的。