Micro-structured high-efficiency semiconductor neutron detectors

Perforated semiconductor diode detectors have been under development for several years at Kansas State University for a variety of neutron detection applications. The detectors are fabricated from high purity n-type Si. Sinusoidal trenches are etched into the substrate, into which shallow p-type junctions are diffused. The trenches are then backfilled with ⁶LiF powder to make the device sensitive to neutrons. Thermal neutron measurements from a 0.0253 eV diffracted neutron beam yielded 17% intrinsic detection efficiency for devices with 50 micron deep trenches and 29% intrinsic detection efficiency for devices with 100 micron deep trenches.