Optimizing silicon UV detector response with antireflection coatings, solar-blind bandpass filters and linear variable filters

JPL’s 2D-doping processes have been proven to exhibit nearly 100% internal QE (i.e. reflection-limited response) from extreme ultraviolet (UV) to the near infrared (NIR). Response can be further optimized and tailored with AR coatings and/or bandpass filters; however, due to silicon’s optical properties, there is no “one size fits all” coating/filter solution that can span the entire UV to NIR wavelength range. Our team has developed a catalog of coating and filter designs suitable for a variety of applications, several of which have already been implemented/deployed. Spectroscopy applications often benefit from a spatially varying detector response optimized according to the instrument’s optical dispersion. Spatially varying the detector response to correspond with instrument dispersion requires that different coatings be applied to different portions of the detector. We have recently demonstrated detectors with a butcher-block style response profile with each portion of the device targeting a specific bandpass—similar to a linear variable filter. This technological advancement is achieved through the intentional and controllable patterning of AR coating(s) on delta-doped arrays. Herein we review implementations/deployments of delta-doped UV detectors with AR and bandpass filter coatings as well as progress on the variable response UV detectors.

喷气推进实验室（JPL）的二维掺杂工艺已被证实可在极紫外（UV）至近红外（NIR）波段实现近乎100%的内量子效率（internal QE，即反射限制型响应）。可通过增透涂层（AR coatings）和/或带通滤波器（bandpass filters）进一步优化并定制其响应特性，但受硅的光学特性限制，不存在能够覆盖全UV至NIR波段的“一刀切”式涂层/滤波方案。我们的研发团队已开发出适配多种应用场景的涂层与滤波设计目录，其中多款设计已实现落地部署。光谱学应用通常可通过匹配仪器光学色散的空间可变探测器响应获得性能提升。要实现与仪器色散匹配的空间可变探测器响应，需在探测器的不同区域施加差异化涂层。我们近期已演示了具备“肉铺砧板”式响应轮廓的探测器——其器件的每个区域均针对特定带通进行优化，原理与线性可变滤波器（linear variable filter）类似。该技术突破通过在δ掺杂阵列（delta-doped arrays）上可控地图案化增透涂层得以实现。本文综述了搭载增透涂层与带通滤波器的δ掺杂紫外探测器的落地部署情况，以及可变响应型紫外探测器的研发进展。