Microlens performance limits in sub-2μm pixel CMOS image sensors
Microlens performance limits in sub-2μm pixel CMOS image sensors
复制标题
DOI：
10.1364/oe.18.005861
复制
发表时间：
2010-03-15
期刊：
影响因子：
3.8
通讯作者：
Catrysse, Peter B.
中科院分区：
文献类型：
--
作者：
Huo, Yijie;Fesenmaier, Christian C.;Catrysse, Peter B.
具有更小像素的CMOS图像传感器被期望使数字成像系统具有更好的分辨率。然而，当像素尺寸小于2 μ m时，衍射会影响像素及其微透镜的光学性能。我们提出了一个第一性原理的CMOS图像传感器像素的横向缩放过程中的微透镜行为的电磁分析。我们建立了一个三金属层像素，衍射防止作为一个聚焦元件时，像素变得小于1.4 μ m的微透镜。这严重降低了红色、绿色和蓝色通道中轴上和轴外像素的性能。我们预测，需要一个金属层或背面照明的像素，以扩展微透镜的功能超出1.4 μ m像素节点。(C)2010年美国光学学会
CMOS image sensors with smaller pixels are expected to enable digital imaging systems with better resolution. When pixel size scales below 2 mu m, however, diffraction affects the optical performance of the pixel and its microlens, in particular. We present a first-principles electromagnetic analysis of microlens behavior during the lateral scaling of CMOS image sensor pixels. We establish for a three-metal-layer pixel that diffraction prevents the microlens from acting as a focusing element when pixels become smaller than 1.4 mu m. This severely degrades performance for on and off-axis pixels in red, green and blue color channels. We predict that one-metal-layer or backside-illuminated pixels are required to extend the functionality of microlenses beyond the 1.4 mu m pixel node. (C) 2010 Optical Society of America