Hybridized High-Z Pixel Detector

Coherent diffraction imaging (CDI) is a revolutionary method of studying micro- and nano-scale materials but it is a time consuming experimental technique that requires valuable synchrotron beam access. This becomes further exasperated when studying materials or structures that require use of higher energy synchrotron x-rays. Given the scarcity of data that high energy testing produces, it is imperative that the x-ray camera be of both high resolution and high efficiency, in order to fully extract as much information as possible in a reasonable duration. Current x-ray cameras constructed from silicon are inherently inefficient and need to be supplanted by newer variants better equipped to stop more energetic x-rays. RMD plans to solve this problem by creating a hybridized x-ray camera that joins a high-Z semiconductor converter layer with a readout circuit. The converter layer will be hybridized at a very fine scale such that spatial resolution will be exemplary. The work plan will concentrate on evaluation of two different custom-produced converter layers. The first option is a GaAs diode array that will be pixelated at in the vicinity of 10 µm and hybridized using conventional bump-bonding means. The second option is a directly deposited film layer of semiconductor TlBr that would lie directly on the readout circuit, thus taking on the spatial resolution of the readout without further need of bonding. Both device types will be fabricated and tested within Phase 1, including contribution of scientists at Brookhaven National Laboratory. The primary beneficiaries of this technology will be those who rely on CDI, and potentially other diffraction techniques, to make discoveries in their varied fields. Additionally, the underlying x-ray detection schemes can be applied to fields such as high resolution medical radiography (mammography) and non-destructive evaluation used in electronics manufacturing.