Digital Imager Enhancement and Investigating Grayscale Photomasks Technologies for Fabrication of Micro-optics

通过将微芯片转变为数字成像传感器和微光学，新的微制造技术已经对社会产生了巨大的影响。从科学仪器到商业摄影，成像传感器现在被用来将传感器与微光学集成在一起，并将控制电子设备集成到单个芯片上。这项拟议的研究结合了光电子学(电子学和光学的结合)和纳米制造这两个领域，纳米制造是用于制造微光学的技术。 1)在光电子学方面，我的研究小组专注于相机中的数字像素阵列。随着时间的推移，成像器会产生越来越多的缺陷，这些缺陷会降低图像质量并缩短传感器的寿命。利用商用摄像机图像和软件分析算法，我们研究了缺陷的发展，以识别错误的像素特征，并准确地定位原因机制。研究将改进已开发的公式，以显示传感器面积更大、灵敏度更高和像素尺寸缩小的趋势会在缺陷强度和显影速度方面产生指数增长，每年可达到1000‘S缺陷。我们将研究基于软件改进图像修复的新方法等应用-使用关于缺陷参数的知识来校正像素，创建参数以提供更好的度量来在像空间站这样的高辐射环境中选择相机，并使用这些缺陷图案和参数来创建相机唯一的“指纹”，用于安全和刑事调查中的法医鉴定。 2)在纳米制造中，我们研究了灰度光掩模的制造，这是一项对低成本3D结构至关重要的技术。现有的商业灰度掩模要么在透明度控制方面非常有限，要么精确但非常昂贵。我们正在开发铋、铟和锡的双金属薄膜，形成一种热致抗蚀剂，在激光曝光下氧化并变得透明。通过在这些胶片上改变激光功率的设备，将开发出直接写入灰度光掩模，在低成本掩模中将透明度控制到高精度(256步)。由于掩模透明度只是微结构垂直控制能力的一个限制因素，因此我们将把这种新的掩模与新的制造方法结合起来，将这些图案转化为用于微光学的非常精确的3D结构。微光学应用需要高度精确的形状来创建适当的光学图像。我们的研究还打算将这种方法应用于微光学的制造，用于改善相机像素，制造失真较小的薄菲涅尔透镜，以及用于平视显示器的薄Gabor透镜。在微流体设计中，我们将在具有独特流体混合特性的微通道中创建3D形状，并将微光学集成到基于荧光的芯片实验室系统中。

New microfabrication techniques have had a dramatic impact on society, by transforming microchips into digital imaging sensors and micro-optics. From scientific instrumentation to commercial photography, imaging sensors are now used to integrate sensors with micro-optics and control electronics onto single chips. This proposed research combines the two areas of opto-electronics (the combination of electronics and optics) and nanofabrication, the technique used to build the micro-optics. 1) In opto-electronics my research group focuses on digital pixel arrays in cameras. Imagers develop a growing number of defects over time that degrades image quality and reduces the sensor life. Using commercial camera images, and software analysis algorithms, we study defect development to identify faulty pixels characteristics, and pinpoint the causal mechanism. Research will improve developed formulas that show the trend towards larger sensor area, higher sensitivity and shrinking pixel size creates exponential growth in both defect strength, and development rates, which can reach 1000’s of defects per year. We will investigate applications such as novel ways to improve image repair based on software-correcting pixels that use knowledge about the defect parameters, creating parameters to give better metrics for choosing cameras in high radiation environments like the Space Station, and using these defect patterns and parameters to create a camera-unique “fingerprint” for forensic identification in security and criminal investigations. 2) In nanofabrication, we investigate the fabrication of grayscale photomasks, which are a technology critical to cost-effective 3D structures. Existing commercial grayscale masks are either very limited in transparency control or accurate but highly expensive. We are developing bimetallic thin films of Bismuth, Indium and Tin, forming a thermal resist which oxidizes and becomes transparent under laser exposure. With equipment that varies the laser power on these films, direct-write grayscale photomasks will be developed which the control transparency to a high accuracy (256 steps) in a low cost mask. Since mask transparency is only one limiting factor in the vertical control ability of microstructure, we will then combine this new mask with new fabrication methods to transfer these patterns into the creation of very accurate 3D structures for micro-optics. The micro-optic application requires highly precise shapes to create the proper optical images. Our research also intends to apply this method to the creation of micro-optics for applications in improving camera pixels, creating less distorting thin Fresnel lenses, and a thin Gabor lens for heads-up displays. In microfluidic designs, we will create 3D shapes in microchannels with unique fluid mixing properties and integrate micro-optics into fluorescence based lab-on-a-chip systems.