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Nano-Engineering of Detector Surfaces to Offer Unprecedented Imager Sensitivity to Soft X-rays and Low Energy Electrons

Looker, Quinn M.; Sanchez, Marcos O.

The focus of this document is to record the learning and process development achieved by the completion of the Nano-Engineering of Detector Surfaces to Offer Unprecedented Imager Sensitivity to Soft X-rays and Low Energy Electrons LDRD. The goal of this effort was to study different silicon detector surface preparation methods such as ion implant parameters, and the addition of a quantum 2-layer superlattice. Enabling the preparation of the surface of silicon detectors (front side illuminated or bonded backside illuminated) increases the responsivity of the diode to shallowly absorbed photons. This increased sensitivity in turn allows for greater fidelity in imaging events that emit low soft X-rays or low energy electrons. Prior work has focused on passivating the surface of a silicon detectors with thin layers (tens of nm thick) of materials to reduce surface recombination sites. Measurements of visible light quantum efficiency, electron responsivity, and pulsed x-ray response indicate that detectors with a 2- layer superlattice enjoy a significant benefit over equivalent detectors using an ion implant at the illuminated surface.