Lalanne Frédéric, Malinge Pierre, Hérault Didier, Jamin-Mornet Clémence, Virollet Nicolas
STMicroelectronics. 850 rue Jean Monnet, 38926 Crolles Cedex. France.
Sensors (Basel). 2018 Jan 20;18(1):305. doi: 10.3390/s18010305.
Mainly driven by automotive applications, there is an increasing interest in image sensors combining a high dynamic range (HDR) and immunity to the flicker issue. The native HDR pixel concept based on a parallel electron and hole collection for, respectively, a low signal level and a high signal level is particularly well-suited for this performance challenge. The theoretical performance of this pixel is modeled and compared to alternative HDR pixel architectures. This concept is proven with the fabrication of a 3.2 μm pixel in a back-side illuminated (BSI) process including capacitive deep trench isolation (CDTI). The electron-based image uses a standard 4T architecture with a pinned diode and provides state-of-the-art low-light performance, which is not altered by the pixel modifications introduced for the hole collection. The hole-based image reaches 750 kh+ linear storage capability thanks to a 73 fF CDTI capacitor. Both images are taken from the same integration window, so the HDR reconstruction is not only immune to the flicker issue but also to motion artifacts.
主要受汽车应用的推动，人们对结合高动态范围（HDR）和抗闪烁问题的图像传感器越来越感兴趣。基于分别针对低信号电平与高信号电平的并行电子和空穴收集的原生HDR像素概念，特别适合应对这一性能挑战。对该像素的理论性能进行建模，并与其他HDR像素架构进行比较。通过在包括电容性深沟槽隔离（CDTI）的背照式（BSI）工艺中制造3.2μm像素，验证了这一概念。基于电子的图像采用具有钳位二极管的标准4T架构，并提供了最先进的低光性能，且这种性能不会因引入用于空穴收集的像素修改而改变。基于空穴的图像借助73 fF的CDTI电容器实现了750 kh+的线性存储能力。两幅图像均取自同一积分窗口，因此HDR重建不仅能抗闪烁问题，还能抗运动伪像。
