Photodiode with controlled current leakage
View Patent ↗The present invention is directed towards radiation detectors and methods of detecting incident radiation. In particular the present invention is directed towards photodiodes with controlled current leakage detector structures and a method of manufacturing photodiodes with controlled current leakage detector structures. The photodiodes of the present invention are advantageous in that they have special structures to substantially reduce detection of stray light. Additionally, the present invention gives special emphasis to the design, fabrication, and use of photodiodes with controlled leakage current.
1. A photodiode comprising:
a front side;
a plurality of electrical contacts in electrical communication with said front side;
a first region wherein said first region is doped with an impurity of a first conductivity type; and
a second region wherein said second region comprises a layer having a plurality of regions which are doped with alternating conductivity types wherein said plurality of regions doped with alternating conductivity types create at least one depletion region that functions as a suction diode, wherein the fabrication of said array involves a masking process comprising the steps of:
applying a n+ mask on said front side
applying a p+ mask on said front side,
applying a first metal layer on said front side,
applying an insulation layer on said front side, and
applying a second metal layer on said front side.
2. The array of claim 1 wherein the masking process further comprises etching said second metal layer to form an aperture leading to an active area on said photodiode.
3. The array of claim 2 wherein said second metal layer prevents stray light from impinging on areas surrounding the active area.
4. The array of claim 1 wherein said front layer comprises a doped material of n+ conductivity type.
5. The array of claim 4 wherein said front n+ layer is in electrical communication with a metal to form a cathode.
6. The array of claim 1 wherein said front layer comprises a doped material of p+ conductivity type.
7. The array of claim 6 wherein front p+ layer is in electrical communication with a metal to form a cathode.
8. The array of claim 1 wherein said insulation layer is a polymide.
9. The array of claim 1 further comprising a first metallization layer on said front side and a second metallization layer on said front side.
10. The array of claim 9 , wherein said second metallization layer substantially prevents stray light from impinging upon areas surrounding an active area.
11. The array of claim 1 comprising a substrate made of n-doped silicon.
12. The array of claim 1 wherein a front surface of said suction diode is partially covered by a passivated oxidized junction, an insulating layer, and a first metal layer.
13. The array of claim 8 wherein the insulating layer is a low temperature oxide layer or nitride layer.
14. The array of claim 1 wherein said front side comprises an n+ layer in electrical communication with a metal to form a cathode.