Mar 20 – 23, 2023
Campus Garching
Europe/Berlin timezone

Conformal deposition of BxC thin films for solid-state neutron detectors

Mar 20, 2023, 4:00 PM
Yards 4 - 6 (Fakultät für Maschinenwesen)

Yards 4 - 6

Fakultät für Maschinenwesen

Board: MO-039
Poster Neutron Instrumentation, Optics, Sample Environment, Detectors, and Software Poster Session MONDAY


Mr Arun Haridas Choolakkal (Linköping University)


10B-based solid-state neutron detectors are a viable replacement to 3He detectors. Neutron irradiation of 10B produce charged detectable ions of 4He and 7Li. The detector efficiency using a planar thin film neutron converter configuration is limited by self-absorption of the conversion products in the layer. A 3D configuration, which allows for the conversion products to exit the converter, offers possibility for a higher detection efficiency. The fundamental challenge with a 3D architecture is to deposit conformal films of converter material on high aspect ratio pixelated sensor-chips. In addition, a low temperature process is required since the detector requires ohmic contacts which needs to be coated before converter layer deposition. We report conformal CVD of BxC thin films on sensor-chip substrates with 10:1 aspect-ratio morphologies, using triethylboron (TEB, B(C2H5)3) as single source CVD precursor at 450° C deposition temperature. Step coverage (SC) calculated from cross-sectional scanning electron microscopy measurements shows that films were conformal with a SC of 1. Quantitative analysis using time-of-flight ERDA reveals that the as-deposited films are B rich carbide material with 82.5 at.% B, 15.6 at.% C and < 2 at.% impurities. Promising neutron detection test results of structured diodes will be presented. By utilizing 10B enriched TEB, this result will open the way for efficient solid state n-detectors incorporating 3D-structured 10B4C converter material.

Primary author

Mr Arun Haridas Choolakkal (Linköping University)


Dr George O'Neill (University of Bergen, Norway) Dr Hans Högberg (Linköping University) Prof. Henrik Pedersen (Linköping University) Prof. Jens Birch (Linköping University) Dr Marco Povoli (SINTEF MiNaLab, Norway)

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