Cheng Wenzheng, Liu Manwen, Li Zheng, Zhao Zhenyang, Li Zhihua
Institute of Microelectronics, Chinese Academy of Sciences, Beijing 100029, China.
School of Integrated Circuits, University of Chinese Academy of Sciences, Beijing 100049, China.
Sensors (Basel). 2022 Aug 24;22(17):6352. doi: 10.3390/s22176352.
The 3D electrode silicon detector eliminates the limit of chip thickness, so it can reduce the electrode spacing (small area) and effectively improve the radiation hardness. In order to expand the application range of the 3D electrode detector, we first propose a 3D large-area silicon detector with a large sensitive volume, and realize multiple floating rings on the upper and lower surfaces of the detector. Due to the influence of different charge states and energy levels in the Si-SiO interface system, the top and bottom of the 3D P+ electrode are more prone to avalanche breakdown in the 3D large-area detector before the detector is completely depleted or the carrier saturation drift velocity is reached. Moreover, the electric field distribution becomes very uneven under the influence of the oxide charge, resulting in non-equilibrium carriers that cannot drift in the optimal path parallel to the detector surface. In this paper, the effect of floating rings on the performance of a 3D large-area silicon detector is studied by TCAD simulation. It can increase avalanche breakdown voltage by 14 times in a non-irradiated environment, and can work safely in a moderate irradiated environment. The charge collection efficiency can be effectively improved by optimizing the drift path.
三维电极硅探测器消除了芯片厚度的限制，因此可以减小电极间距（小面积）并有效提高辐射硬度。为了扩大三维电极探测器的应用范围，我们首先提出了一种具有大灵敏体积的三维大面积硅探测器，并在探测器的上下表面实现了多个浮动环。由于Si-SiO界面系统中不同电荷态和能级的影响，在三维大面积探测器完全耗尽或达到载流子饱和漂移速度之前，三维P+电极的顶部和底部更容易发生雪崩击穿。此外，在氧化物电荷的影响下，电场分布变得非常不均匀，导致非平衡载流子无法在平行于探测器表面的最佳路径中漂移。本文通过TCAD模拟研究了浮动环对三维大面积硅探测器性能的影响。在非辐照环境下，它可以将雪崩击穿电压提高14倍，并且可以在中等辐照环境下安全工作。通过优化漂移路径，可以有效提高电荷收集效率。
