Novel III-V heterostructures and designs for high-performance avalanche photodiode devices

雪崩光电二极管（APD）是一种专门的半导体器件，用于检测光，在某些应用中，甚至是单个光子。因此，APD通常用于需要灵敏光检测的各种应用 **。他们已经成功地制造了在不同 ** 波长的操作，测距应用，和各种光传感解决方案。这些器件的一个共同特征 ** 是倍增区：一个电场强度非常高的区域，在该区域中，激发的光电流引起碰撞电离的级联，在阳极和阴极产生显着放大的信号。APD器件在1.5微米波长范围内有多种应用。InP基外延材料 ** 已被完善以优化使用InGaAs和InP异质结构的APD性能。通过外延掺杂和扩散掺杂相结合的方法，得到了这些材料的掺杂分布。为了扩展到新的应用，进一步提高III-V APD的性能并 ** 补充现有的基准产品非常重要。需要改进的具体领域包括暗电流（体电流和 ** 表面电流）、雪崩区更陡的I-V曲线（因此APD可以在更远离 ** 击穿电压的情况下更安全地工作）以及更低的固有噪声等效功率（在 ** 接收超低光水平时获得更好的信噪比（SNR）），并在激光测距仪应用中实现更远的测距。APD需要 ** 特殊的设计和工艺控制，因为启动雪崩增益的电场具有非常严格的 ** 要求，并且创建III-V**APD所需的各种层的材料和掺杂水平的相互作用是复杂的，并且可以预期产生良好性能的值范围很窄。该CRD** 项目将通过设计具有更好优化的AlInAs/InGaAs/InP外延层和掺杂设计的新型异质结构 ** 策略来优化APD器件性能。

An avalanche photodiode (APD) is a specialized semiconductor device used for the detection of light and, in**certain applications, even individual photons. The APDs are therefore typically used in various applications**requiring sensitive detection of light. They have been successfully manufactured for operation at different**wavelengths, for ranging applications, and various light sensing solutions. A common feature of these devices**is a multiplication region: a region of very high electric field strength in which excited photo-current causes a**cascade of impact ionizations yielding a significantly amplified signal at the anode and cathode. There are**several applications for APD devices in the wavelength range of 1.5microns. The InP-based epitaxial materials**have been perfected to optimize the APD performance using InGaAs and InP heterostructures. The doping**profiles have been obtained by combining epitaxial doping and diffusion doping technique in these materials.**To expand into new applications it is important to further improve the performance of such III-V APDs and**complement the available baseline products. Specific areas for improvement are dark currents (bulk and**surface), steeper I-V curve in the avalanche region so the APD can be operated more safely further from the**breakdown voltage, and lower intrinsic noise equivalent power for better signal-to-noise ratio (SNR) when**receiving ultra-low light levels and enabling further ranging in laser-range finder applications. APDs require**exceptional design and process controls since the electric fields that initiate avalanche gain have very tight**requirements and the interaction of the materials and doping levels of the various layers needed to create a III-V**APD are complex with a narrow range of values that can be expected to yield good performance. This CRD**project will allow the optimization of the APD device performance by designing novel heterostructure**strategies with better optimized AlInAs/InGaAs/InP epilayers and doping designs.