Investigation of charge-collection efficiency of Kyoto's X-ray astronomical SOI pixel sensors, XRPIX
Investigation of charge-collection efficiency of Kyoto's X-ray astronomical SOI pixel sensors, XRPIX
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京都X射线天文SOI像素传感器XRPIX的电荷收集效率研究
DOI：
10.1016/j.nima.2014.05.025
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发表时间：
2014
期刊：
影响因子：
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通讯作者：
Matsumura, Hideaki; Tsuru, Takeshi Go; Tanaka, Takaaki; Nakashima, Shinya; Ryu, Syukyo G.; Takeda, Ayaki; Arai, Yasuo; Miyoshi, Toshinobu
中科院分区：
文献类型：
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作者：
Matsumura, Hideaki; Tsuru, Takeshi Go; Tanaka, Takaaki; Nakashima, Shinya; Ryu, Syukyo G.; Takeda, Ayaki; Arai, Yasuo; Miyoshi, Toshinobu
我们正在开发基于绝缘体上硅CMOS技术的单片有源像素传感器，称为XRPIX，用于x射线天文学。我们最近研究的一个关键问题是电荷收集不完全对光谱学性能的影响。在本文中，我们报告了几种具有不同像素内结构或由不同晶圆制成的器件的光谱响应。我们发现，当作为电荷收集节点的埋藏p阱的尺寸较小时，发射谱线表现出较大的低能尾。此外，在电荷共享事件中，发射线的峰值通道比没有电荷共享的通道更低。随着像素中心与入射光子位置之间距离的增加，这种峰移更加明显。这表明电荷收集效率在像素边界处下降。我们还发现电荷收集效率取决于耗尽层和绝缘层界面处的电场强度。
We are developing a monolithic active pixel sensor referred to as XRPIX for X-ray astronomy on the basis of silicon-on-insulator CMOS technology. A crucial issue in our recent development is the impact of incomplete charge collection on the spectroscopic performance. In this paper, we report the spectral responses of several devices having different intra-pixel structures or produced from different wafers. We found that an emission line spectrum exhibits large low-energy tails when the size of the buried p-well, which acts as the charge-collection node, is small. Moreover, in charge sharing events, the peak channels of the emission lines shift toward channels lower than those without charge sharing. This peak shift is more pronounced as the distance between the pixel center and the position of incident photon increases. This suggests that the charge-collection efficiency is degraded at the pixel boundary. We also found that the charge-collection efficiency depends on the strength of the electric field at the interface of the depletion and insulator layers.