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

雪崩光电二极管(雪崩光电二极管)是一种专门的半导体器件，用于探测光，在**某些应用中，甚至用于探测单个光子。因此，APD通常用于需要对光进行敏感检测的各种应用**。它们已经成功地制造出来，用于不同**波长的工作，用于测距应用，以及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**级联的碰撞电离，在阳极和阴极产生显著放大的信号。在1.5微米的波长范围内，apd器件有**几种应用。基于InP的外延材料**已经得到了完善，以优化采用InGaAs和InP异质结的雪崩光电二极管的性能。通过在这些材料中结合外延掺杂和扩散掺杂技术，获得了掺杂**分布。**为了扩展到新的应用，重要的是进一步提高这种III-V APD的性能，并**补充现有的基线产品。需要改进的具体领域包括暗电流(体相和**表面)、雪崩区更陡峭的I-V曲线，以便在距离击穿电压更远的地方更安全地工作，以及降低本征噪声当量功率，以便在**接收超低光级时获得更好的信噪比(SNR)，并在激光测距应用中实现更远的测距。APDS需要**特殊的设计和工艺控制，因为引发雪崩增益的电场有非常严格的**要求，而产生III-V**雪崩二极管所需的不同层的材料和掺杂水平的相互作用是复杂的，可以预期产生良好性能的值范围很窄。该CRD**项目将通过设计新颖的异质结构**策略以及更好地优化AlInAs/InGaAs/InP外延层和掺杂设计，来优化APD器件的性能。

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.