SBIR Phase II: Advancing Beyond the Photodiode - Deep Sub-micron Pixels for Next-generation Image Sensors

这个小企业创新研究第二阶段项目的重点是开发使用亚微米像素成像传感器阵列的低噪声和提高对比度的紧凑型相机模块。该项目的商业潜力集中在开发用于内窥镜、导航和机器人手术系统等的紧凑型相机上。将这些摄像头嵌入内窥镜系统，甚至手术工具本身，允许在广泛的医学专业范围内进行新的治疗，否则这些治疗是不可能的。转向一些普通手术的微创形式，估计可以节省140亿美元的医疗支出。肿瘤学、泌尿学、胃肠病学、妇女健康和儿科医学只是这些超小型相机将显著受益的一些专业。更广泛的影响最终将来自于在高密度阵列中以独特的方式利用亚微米像素。传感器?小尺寸和快速响应时间为空间和时间过采样提供了独特的机会。由此产生的大量像素可用于紧凑的多孔径排列，以提供优于传统半导体成像阵列、多光谱成像、三维图像重建、无运动自动对焦或上述某些组合的显着增强的颜色映射，从而在医疗成像、国防、机器人和消费电子产品中提供独特的应用。相机系统的小型化要求像素尺寸不断缩小。然而，在某一点上，一个像素可以容纳的最大光电子变得有限，产生低信噪比和较差的动态范围。该项目开发了一种新型光学传感器，其灵敏度可保持在数百纳米。随着该传感器尺寸的减小，最大可测量光强可以保持不变，信噪比增加，从而显著改善图像质量。动态范围和色彩/特征再现。这一结果与传统像素的行为形成鲜明对比，传统像素的最大强度阈值随着像素尺寸的减小而减小，噪声随着像素尺寸的减小而增加。将这些图像传感器应用于实际需要从基于砷化镓的设备过渡到基于硅的设备。工作重点是1)最终确定设计参数，制作和表征系统的电学特性和光学响应；2)制作和表征线性光电探测器阵列，用于创建线性图像和由线性图像组装的二维图像，以表征原型的噪声，对比度和其他图像质量参数。

This Small Business Innovation Research Phase II project focuses on developing compact camera modules with lower noise and improved contrast using a submicron pixel imaging sensor array. The commercial potential of this project centers on developing compact cameras for endoscopes, navigational and robotic surgical systems and more. Embedding these cameras in endoscope systems, and even the surgical tools themselves, permits new treatments across a broad range of medical specialties that otherwise are not possible. Switching to the minimally invasive forms of some common surgeries could save an estimated $14 billion in healthcare spending. Oncology, urology, gastroenterology, women's health and pediatric medicine are just some of the specialties that will significantly benefit from these ultra-compact cameras. A broader impact will ultimately come from utilizing submicron pixels in unique ways in high density arrays. The sensor?s small size and fast response times offer unique opportunities for spatial and temporal oversampling. The resulting large numbers of pixels can be employed in a compact multi-aperture arrangement to deliver significantly enhanced color mapping over traditional semiconductor imaging arrays, multispectral imaging, 3-dimensional image reconstruction, motion free auto-focusing, or some combination of the above, providing unique applications in medical imaging, defense, robotics, and consumer electronics. The miniaturization of camera systems calls for the continuous shrinking of pixel sizes. At a certain point, however, the maximum photo-electrons a pixel can hold becomes limited, yielding low signal-to-noise ratios and poor dynamic range. This project develops a novel optical sensor that maintains sensitivity down to hundreds of nanometers. As the size of this sensor decreases, the maximum measurable light intensity can remain constant and the signal-to-noise increases, bringing significant improvements to images? dynamic range and color/feature rendition. This result stands in stark contrast to the behavior of conventional pixels where maximum intensity threshold scales down with pixel size and noise increases with decreasing pixel size. Reducing these image sensors to practice requires transitioning from gallium arsenide based devices to silicon. The work focuses on 1) finalizing design parameters, fabrication, and characterization of the electrical properties and optical response of the system and 2) fabrication and characterization of a linear photodetector array for the creation of both linear images and 2-D images assembled from linear images to characterize the noise, contrast and other image quality parameters of the prototype.