A high-performance scintillator-silicon-well X-ray microdetector based on DRIE techniques

This paper proposes an X-ray detector based on an array of scintillator cry stals, CsI:Tl, encapsulated in a wen that is etched into a silicon substrat e by deep reactive ion etching. The X-ray energy is first converted to visi ble light which is detected by a photodetector in the well bottom. DRIE tec hniques are used to achieve perfect vertical side-walls 515 mum deep, 100 m um pixel square size and to maximize the fill factor. The inner walls of th e well that are coated with aluminum for improving the number of photons wh ich arrives to the detector and for reducing cross-talk between adjacent we lls. Simulations and modeling show an improvement of approximately 26% in t he detection efficiency using an aluminum layer. (C) 2001 Elsevier Science B.V. All rights reserved.