Microstructured semiconductor neutron detectors

摘要

Perforated semiconductor neutron detectors are compact diode detectors that operate at low power andcan be fashioned to have high thermal neutron detection efficiency. Fabricated from high-purity Siwafers, the perforations are etched into the diode surface with ICP-RIE and backfilled with ~6LiF neutronreactive material. The intrinsic thermal neutron detection efficiency depends upon many factors,including the perforation geometry, size, and depth. Devices were fabricated from high resistivity10 kΩ cm n-type Si with conformal p-type shallow junction diffusions into the perforations, whichdemonstrate improved neutron detection performance over previous selectively diffused designs.A comparison was made to previous selectively diffused designs, and pulse height spectra showimproved signal-to-noise ratio, higher neutron counting efficiency, and excellent gamma-raydiscrimination. Devices with 20 (average) μmwide 100μm deep sinusoidal trenches yielded intrinsicthermal neutron detection efficiencies of 11.94+0.078.