Photodiode with controlled current leakage
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 substrate having at least a front side and a back side;
a plurality of electrical contacts in electrical communication with said front side;
a first region wherein said first region is heavily doped with an impurity of a first conductivity type;
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 a plurality of depletion regions;
a first metallization layer on said front side; and
a second metallization layer on said front side wherein said second metallization layer creates an aperture to an active area.
2. The photodiode of claim 1 , wherein said second metallization layer on said front side substantially prevents stray light from impinging upon the areas surrounding the active area.
3. The photodiode of claim 1 , wherein said first region is made of n-doped silicon.
4. The photodiode of claim 1 , wherein said photodiode has a front surface and said front surface is partially covered by a passivated oxidized junction, an insulating layer, and a first metal layer.
5. The photodiode of claim 4 wherein the insulating layer is a polymide.
6. The photodiode of claim 4 wherein the insulating layer is a low temperature oxide or nitride layer.
7. The photodiode of claim 1 wherein said second region comprises a n+ layer in electrical communication with a metal to form a cathode.
8. The photodiode of claim 1 wherein said second region comprises a doped material of p+ conductivity type.
9. The photodiode of claim 8 wherein said p+ layer is in electrical communication with a metal to form an anode.