Neutron-detecting apparatuses and methods of fabrication
Neutron-detecting structures and methods of fabrication are provided which include: a substrate with a plurality of cavities extending into the substrate from a surface; a p-n junction within the substrate and extending, at least in part, in spaced opposing relation to inner cavity walls of the substrate defining the plurality of cavities; and a neutron-responsive material disposed within the plurality of cavities. The neutron-responsive material is responsive to neutrons absorbed for releasing ionization radiation products, and the p-n junction within the substrate spaced in opposing relation to and extending, at least in part, along the inner cavity walls of the substrate reduces leakage current of the neutron-detecting structure.
1. A method comprising:
fabricating a neutron-detecting structure, the fabricating comprising:
providing a substrate comprising a plurality of cavities extending into the substrate from a surface thereof;
forming a p-n junction within the substrate and extending, at least in part, in spaced opposing relation to inner cavity walls of the substrate defining the plurality of cavities therein;
providing a neutron-responsive material within the plurality of cavities, the neutron-responsive material being responsive to neutrons absorbed thereby for releasing ionization radiation reaction products, wherein the p-n junction within the substrate spaced in opposing relation to and extending, at least in part, along the inner cavity walls of the substrate reduces leakage current of the neutron-detecting structure;
wherein the p-in junction within the substrate is a continuous p-n junction, the continuous p-n junction being disposed, at least in part, parallel to the surface of the substrate from which the plurality of cavities extend into the substrate, as well as in spaced opposing relation to the inner cavity walls of the substrate; and
wherein the continuous p-n junction is spaced from the surface of the substrate a greater distance than the continuous p-n junction is spaced in opposing relation to the inner cavity walls of the substrate.
2. The method of claim 1 , wherein forming the p-n junction comprises depositing a conformal layer of p-type dopant material at a first temperature, and subsequently annealing the conformal layer of p-type dopant material at a second temperature, the second temperature being higher than the first temperature, and the annealing facilitating forming a continuous p-n junction extending, at least in part, within the substrate in spaced opposing relation to the inner cavity walls of the substrate.
3. The method of claim 2 , wherein the second temperature is at least about 100° C. to 300° C. higher than the first temperature.
4. The method of claim 2 , wherein the conformal layer of p-type dopant material comprises a conformal layer of neutron-responsive material deposited within the plurality of cavities, the conformal layer of neutron-responsive material comprising at least one of enriched boron or a compound including enriched boron.
5. The method of claim 2 , wherein the continuous p-n junction is deposited, in part, in spaced opposing relation to the surface of the substrate, the continuous p-n junction being spaced from the surface of the substrate a greater distance than the continuous p-n junction is spaced from the inner cavity walls of the substrate.
6. The method of claim 1 , wherein at least one cavity of the plurality of cavities within the substrate is, at least in part, a hexagonal-cross-sectional-shaped cavity.
7. The method of claim 1 , wherein providing the substrate further comprises arraying, at least in part, the plurality of cavities in the substrate in a honeycomb pattern.
8. The method of claim 1 , wherein fabricating the neutron-detecting structure comprises fabricating the neutron-detecting structure to operate at zero bias voltage.
9. The method of claim 1 , wherein the neutron-responsive material within the plurality of cavities comprises a hydrogen-rich aromatic polymer material.
10. The method of claim 1 , wherein forming the p-n junction within the substrate comprises disposing a conformal layer of material over the substrate and within the plurality of cavities extending therein, and annealing the conformal layer of material to form, at least in part, the p-n junction within the substrate.
11. The method of claim 10 , further comprising removing the conformal layer of material from the plurality of cavities after the annealing and before the providing of the neutron-responsive material within the plurality of cavities.