Wassell E J, Adams J S, Bandler S R, Betancourt-Martinez G L, Chiao M P, Chang M P, Chervenak J A, Datesman A M, Eckart M E, Ewin A J, Finkbeiner F M, Ha J Y, Kelley R, Kilbourne C A, Miniussi A R, Sakai K, Porter F, Sadleir J E, Smith S J, Wakeham N A, Yoon W
NASA Goddard Space Flight Center, Greenbelt, MD, 20771, USA. Stinger-Ghaffarian Technologies, Inc., Greenbelt, MD 20771 USA.
NASA Goddard Space Flight Center, Greenbelt, MD, 20771, USA. CRESST, University of Maryland, College Park, MD 20742 USA.
IEEE Trans Appl Supercond. 2017 Jun;27(4). doi: 10.1109/TASC.2016.2633783. Epub 2016 Dec 1.
We are developing superconducting transition-edge sensor (TES) microcalorimeter focal planes for versatility in meeting specifications of X-ray imaging spectrometers including high count-rate, high energy resolution, and large field-of-view. In particular, a focal plane composed of two sub-arrays: one of fine-pitch, high count-rate devices and the other of slower, larger pixels with similar energy resolution, offers promise for the next generation of astrophysics instruments, such as the X-ray Integral Field Unit (X-IFU) instrument on the European Space Agency's Athena mission. We have based the sub-arrays of our current design on successful pixel designs that have been demonstrated separately. Pixels with an all gold X-ray absorber on 50 and 75 micron scales where the Mo/Au TES sits atop a thick metal heatsinking layer have shown high resolution and can accommodate high count-rates. The demonstrated larger pixels use a silicon nitride membrane for thermal isolation, thinner Au and an added bismuth layer in a 250 micron square absorber. To tune the parameters of each sub-array requires merging the fabrication processes of the two detector types. We present the fabrication process for dual production of different X-ray absorbers on the same substrate, thick Au on the small pixels and thinner Au with a Bi capping layer on the larger pixels to tune their heat capacities. The process requires multiple electroplating and etching steps, but the absorbers are defined in a single ion milling step. We demonstrate methods for integrating heatsinking of the two types of pixel into the same focal plane consistent with the requirements for each sub-array, including the limiting of thermal crosstalk. We also discuss fabrication process modifications for tuning the intrinsic transition temperature (T) of the bilayers for the different device types through variation of the bilayer thicknesses. The latest results on these "hybrid" arrays will be presented.
我们正在开发超导转变边缘传感器（TES）微热量计焦平面，以满足X射线成像光谱仪的各种规格要求，包括高计数率、高能量分辨率和大视场。特别是，由两个子阵列组成的焦平面：一个是细间距、高计数率器件，另一个是能量分辨率相似但速度较慢、像素较大的子阵列，为下一代天体物理仪器带来了希望，例如欧洲航天局雅典娜任务中的X射线积分场单元（X-IFU）仪器。我们当前设计的子阵列基于已分别得到验证的成功像素设计。在50和75微米尺度上带有全金X射线吸收器的像素，其中钼/金TES位于厚金属散热层之上，已显示出高分辨率并且能够承受高计数率。已验证的较大像素使用氮化硅膜进行热隔离，在250微米见方的吸收器中使用更薄 的金并添加了铋层。要调整每个子阵列的参数，需要合并两种探测器类型的制造工艺。我们展示了在同一基板上双重生产不同X射线吸收器的制造工艺，小像素上是厚金，大像素上是带有铋覆盖层的更薄金，以调整它们的热容量。该工艺需要多个电镀和蚀刻步骤，但吸收器在单个离子铣削步骤中定义。我们展示了将两种类型像素的散热集成到同一焦平面的方法，这与每个子阵列的要求一致，包括限制热串扰。我们还讨论了通过改变双层厚度来调整不同器件类型双层的固有转变温度（T）的制造工艺修改。将展示这些“混合”阵列的最新结果。
