硅基APD近紫外探测增强的结构优化研究

发布时间：2018-04-19 14:40

本文选题：Si-APD + 掺杂结构　；参考：《哈尔滨工业大学》2015年硕士论文

【摘要】：在光电探测领域,硅基雪崩光电二极管(Si-APD)一直以其高增益、低噪声、响应速度快而被广为应用。但随着近紫外天文学与气象学、近紫外通讯与制导等方面的快速发展,Si-APD在紫光区域较低的灵敏度一直制约了其在近紫外探测领域的发展。本论文从APD分层结构的掺杂分布、几何参数与APD表面的膜系统两方面来分析影响Si-APD紫光区域探测灵敏度的因素。首先在典型的吸收场控倍增分离(SACM)型APD的结构模型下,推导了各层电场强度分布,并得到了与增益系数和击穿电压的关系;接着从光吸收理论出发,探究了从入射光子一直到产生雪崩电流的微观行为,并得到了非光敏感层厚度是制约其近紫外光探测灵敏度的结论;然后通过分层计算的方式得到了各层分别对量子效率的贡献;另外本文通过菲涅尔原理推导了表面增透膜满足的条件并创新性的在Si-APD表面镀折射率高低相间排布的多层膜系统,在保证透过率的同时达到了光学选频的目的。然后通过Matlab计算得到了400nm处35.0%的量子效率时的最优掺杂分布。最后通过Silvaco建立Si-APD器件结构模型仿真,通过优化工艺流程得到与优化结构近似的优化模型,得到优化结构的探测灵敏度250A/W(406nm),比初始结构的探测灵敏度18.9A/W(400nm)提高了12.2倍。流片测试结果为406nm时80.3A/W的探测灵敏度,进一步证实了优化方案的可行性。
[Abstract]:Silicon based avalanche photodiode (Si-APD) has been widely used in the field of photoelectric detection because of its high gain, low noise and fast response speed.However, with the rapid development of near ultraviolet astronomy and meteorology, near ultraviolet communication and guidance, the low sensitivity of Si-APD in the ultraviolet region has been restricting its development in the field of near ultraviolet detection.In this paper, the factors that influence the detection sensitivity of APD are analyzed from the aspects of doping distribution, geometric parameters and the film system of APD surface.Firstly, the electric field intensity distribution of each layer is deduced under the typical absorption field controlled multiplication separation (APD) structure model, and the relation with gain coefficient and breakdown voltage is obtained, and then, based on the optical absorption theory, the electric field intensity distribution of each layer is derived.The microscopic behavior from incident photon to avalanche current is investigated, and the conclusion that the thickness of non-light sensitive layer restricts the sensitivity of near-ultraviolet detection is obtained.Then the contribution of each layer to quantum efficiency is obtained by delamination calculation. In addition, the Fresnel principle is used to deduce the condition of surface antireflection film and to create a multilayer system of coating refractive index between high and low phases on the surface of Si-APD.The optical frequency selection is achieved at the same time as the transmittance is guaranteed.Then the optimal doping distribution at 35.0% quantum efficiency at 400nm is obtained by Matlab calculation.Finally, the structure model of Si-APD device is simulated by Silvaco, and the optimization model is obtained by optimizing the process flow. The detection sensitivity of the optimized structure is 250A / W / W 406nmM, which is 12.2 times higher than that of the initial structure (18.9 A / W / W 400nm).The detection sensitivity of 80.3A/W when the flow sheet test result is 406nm further proves the feasibility of the optimized scheme.
【学位授予单位】：哈尔滨工业大学
【学位级别】：硕士
【学位授予年份】：2015
【分类号】：TN23

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