This paper reports on the device processing and characterization of hexagonalboron nitride (hBN) based solid-state thermal neutron detectors, where hBNthickness varied from 2.5 to 15 microns. These natural hBN epilayers (with19.9% B-10) were grown by a low pressure chemical vapor deposition process.Complete dry processing was adopted for the fabrication of thesemetal-semiconductor-metal (MSM) configuration detectors. These detectors showedintrinsic thermal neutron detection efficiency values of 0.86%, 2.4%, 3.15%,and 4.71% for natural hBN thickness values of 2.5, 7.5, 10, and 15 microns,respectively. Measured efficiencies are very close (more than 92%) to thetheoretical maximum efficiencies for corresponding hBN thickness values forthese detectors. This clearly shows the hBN thickness scalability of thesedetectors. A 15-micron thick hBN based MSM detector is expected to yield anefficiency of 21.4%, if enriched hBN (with ~100% B-10) is used instead ofnatural hBN. These results demonstrate that the fabrication of hBN thicknessscalable highly efficient thermal neutron detectors is possible.
展开▼
