Author s personal copy Microstructured semiconductor neutron detectors
Perforated semiconductor neutron detectors are compact diode detectors that operate at low power and can be fashioned to have high thermal neutron detection efficiency. Fabricated from high purity Si wafers, the perforations are etched into the diode surface with ICP RIE and backfilled with LiF neutron reactive material. The intrinsic thermal neutron detection efficiency depends upon many factors, including the perforation geometry, size, and depth. Devices were fabricated from high resistivity 10 kO cm n type Si with conformal p type shallow junction diffusions into the perforations, which demonstrate improved neutron detection performance over previous selectively diffused designs. A comparison was made to previous selectively diffused designs, and pulse height spectra show improved signal to noise ratio, higher neutron counting efficiency, and excellent gamma ray discrimination. Devices with 20 daverageThmm wide 100mm deep sinusoidal trenches yielded intrinsic thermal neutron detection efficiencies of 11:9470:078% 2009 Elsevier B.V. All rights reserved.