Fabrication of Pillar-structured thermal neutron detectors

Pillar detector is an innovative solid state device structure that leverages advanced semiconductor fabrication technology to produce a device for thermal neutron detection. State-of-the-art thermal neutron detectors have shortcomings in achieving simultaneously high efficiency, low operating voltage while maintaining adequate fieldability performance. By using a 3-dimensional silicon PIN diode pillar array filled with isotopic boron 10, (¹⁰B) a high efficiency device is theoretically possible. The fabricated pillar structures reported in this work are composed of 2 mum diameter silicon pillars with a 4 mum pitch and pillar heights of 6 and 12 mum. The pillar detector with a 12 mum height achieved a thermal neutron detection efficiency of 7.3% at 2 V.