Centroid contact radiation detector system and method
A centroid contact radiation detector system/method providing for low capacitance and noise insensitivity is disclosed. The system incorporates a P-type/N-type bulk germanium volume (PGEV/NGEV) having an internal well cavity void (IWCV). The external NGEV surfaces incorporate an N+/P+ electrode and the surface of the IWCV incorporates a centrally located P+/N+ contact (CPPC). The IWCV surface is constructed and the CPPC is positioned within the IWCV so as to provide uniform symmetric field distribution within the PGEV/NGEV and improved noise immunity. The CPPC may be formed using point, reduced-area, medium-area, large-area, hemispherical, semi-hemispherical, and cylindrical annulus contact constructions. The PGEV/NGEV may be constructed using cylindrical, regular polyhedral, or spherical forms.
1. A centroid contact radiation detector (CCRD) system comprising:
(a) P-type bulk germanium volume (PGEV);
(b) N+ electrode; and
(c) P+ electrode;
wherein:
said PGEV is symmetrically constructed along a central vertical longitudinal axis;
said PGEV further comprises an internal surface and an external surface;
said external surface comprises an outer surface and a cavity entry region (CER);
said PGEV further comprises an internal well cavity void (IWCV) coincident with said CER, the surface of said IWCV forming said internal surface;
said IWCV further comprises one or more side surfaces and a contact surface;
said N+ electrode is formed on said external surface; and
said P+ electrode is located on said contact surface at a geometric centroid of said PGEV.
2. The centroid contact radiation detector (CCRD) system of claim 1 wherein said PGEV forms a cylindrical annulus having a height H, external diameter D, and internal diameter I; said external surface of said PGEV forms a cylinder of said diameter D; said internal surface of said PGEV forms a cylinder of said diameter I; said P+ electrode forms a cylindrical annulus of said diameter I at a midplane of said cylindrical PGEV along a longitudinal centerline of said cylindrical PGEV; and said P+ electrode cylindrical annulus has a surface width less than or equal to 30% of said height H.
3. The centroid contact radiation detector (CCRD) system of claim 1 wherein said external surface of said PGEV forms a shape selected from a group consisting of: cylinder; dome; sphere; frustum; conic frustum; and regular polyhedron prism.
4. The centroid contact radiation detector (CCRD) system of claim 1 wherein said IWCV forms a shape selected from a group consisting of: cylinder; frustum; conic frustum; dome; and regular polyhedron prism.
5. The centroid contact radiation detector (CCRD) system of claim 1 wherein said P+ electrode forms a shape selected from a group consisting of: point contact; circular plate; hemisphere; semi-hemisphere; and cylindrical annulus.
6. The centroid contact radiation detector (CCRD) system of claim 1 wherein said P+ electrode is formed on only a portion of said internal surface.
7. The centroid contact radiation detector (CCRD) system of claim 1 wherein said N+ electrode is formed on only a portion of said external surface.
8. The centroid contact radiation detector (CCRD) system of claim 1 wherein said N+ electrode is formed on only a portion of said external surface and is adjacent to an isolation groove formed within said PGEV.
9. The centroid contact radiation detector (CCRD) system of claim 1 wherein said N+ electrode comprises an electrical contact selected from a group consisting of: implanted donor species; implanted acceptor species; diffused donor species; diffused acceptor species; surface barrier contact; amorphous semiconductor contact; metal oxide semiconductor (MOS) contact; metal insulator semiconductor (MIS) contact; Schottky barrier contacts; rectifying semiconductor contact; blocking semiconductor contact; and ohmic semiconductor contact.
10. The centroid contact radiation detector (CCRD) system of claim 1 wherein said P+ electrode comprises an electrical contact selected from a group consisting of: implanted donor species; implanted acceptor species; diffused donor species; diffused acceptor species; surface barrier contact; amorphous semiconductor contact; metal oxide semiconductor (MOS) contact; metal insulator semiconductor (MIS) contact; Schottky barrier contacts; rectifying semiconductor contact; blocking semiconductor contact; and ohmic semiconductor contact.
11. A centroid contact radiation detector (CCRD) system comprising:
(a) N-type bulk germanium volume (NGEV);
(b) P+ electrode; and
(c) N+ electrode;
wherein:
said NGEV is symmetrically constructed along a central vertical longitudinal axis;
said NGEV further comprises an internal surface and an external surface;
said external surface comprises an outer surface and a cavity entry region (CER);
said NGEV further comprises an internal well cavity void (IWCV) coincident with said CER, the surface of said IWCV forming said internal surface;
said IWCV further comprises one or more side surfaces and a contact surface;
said P+ electrode is formed on said external surface; and
said N+ electrode is located on said contact surface at a geometric centroid of said NGEV.
12. The centroid contact radiation detector (CCRD) system of claim 11 wherein said NGEV forms a cylindrical annulus having a height H, external diameter D, and internal diameter I; said external surface of said NGEV forms a cylinder of said diameter D; said internal surface of said NGEV forms a cylinder of said diameter I; said N+ electrode forms a cylindrical annulus of said diameter I at a midplane of said cylindrical NGEV along a longitudinal centerline of said cylindrical NGEV; and said N+ electrode cylindrical annulus has a surface width less than or equal to 30% of said height H.
13. The centroid contact radiation detector (CCRD) system of claim 11 wherein said external surface of said NGEV forms a shape selected from a group consisting of: cylinder; dome; sphere; frustum; conic frustum; and regular polyhedron prism.
14. The centroid contact radiation detector (CCRD) system of claim 11 wherein said IWCV forms a shape selected from a group consisting of: cylinder; frustum; conic frustum; dome; and regular polyhedron prism.
15. The centroid contact radiation detector (CCRD) system of claim 11 wherein said N+ electrode forms a shape selected from a group consisting of: point contact; circular plate; hemisphere; semi-hemisphere; and cylindrical annulus.
16. The centroid contact radiation detector (CCRD) system of claim 11 wherein said N+ electrode is formed on only a portion of said internal surface.
17. The centroid contact radiation detector (CCRD) system of claim 11 wherein said P+ electrode is formed on only a portion of said external surface.
18. The centroid contact radiation detector (CCRD) system of claim 11 wherein said P+ electrode is formed on only a portion of said external surface and is adjacent to an isolation groove formed within said NGEV.
19. The centroid contact radiation detector (CCRD) system of claim 11 wherein said P+ electrode comprises an electrical contact selected from a group consisting of: implanted donor species; implanted acceptor species; diffused donor species; diffused acceptor species; surface barrier contact; amorphous semiconductor contact; metal oxide semiconductor (MOS) contact; metal insulator semiconductor (MIS) contact; Schottky barrier contacts; rectifying semiconductor contact; blocking semiconductor contact; and ohmic semiconductor contact.
20. The centroid contact radiation detector (CCRD) system of claim 11 wherein said N+ electrode comprises an electrical contact selected from a group consisting of: implanted donor species; implanted acceptor species; diffused donor species; diffused acceptor species; surface barrier contact; amorphous semiconductor contact; metal oxide semiconductor (MOS) contact; metal insulator semiconductor (MIS) contact; Schottky barrier contacts; rectifying semiconductor contact; blocking semiconductor contact; and ohmic semiconductor contact.