Front Illuminated Back Side Contact Thin Wafer Detectors

Abstract

The present invention is directed toward a detector structure, detector arrays, a method of detecting incident radiation, and a method of manufacturing the detectors. The present invention comprises several embodiments that provide for reduced radiation damage susceptibility, decreased affects of cross-talk, and increased flexibility in application. In one embodiment, the present invention comprises a plurality of front side illuminated photodiodes, optionally organized in the form of an array, with both the anode and cathode contact pads on the back side. The front side illuminated, back side contact photodiodes have superior performance characteristics, including less radiation damage, less crosstalk using a suction diode, and reliance on reasonably thin wafers. Another advantage of the photodiodes of the present invention is that high density with high bandwidth applications can be effectuated.

1 - 37 . (canceled) 
     
     
         38 . A photodiode comprising:
 a. a silicon wafer having a front side and a back side, wherein said wafer has a thickness of 300 microns or less and wherein each of said front side and back side has a surface;   b. a n+ layer formed within said wafer and located proximate to said back side;   c. a p+ layer formed with said wafer and located proximate to said front side, wherein said p+ layer and said n+ layer are separated by an area and wherein said area comprises an active region;   d. a first metallic area formed on the front side surface, said first metallic area in electrical communication with the p+ layer and forming an anode;   e. a second metallic area formed on the back side surface, said second metallic area in electrical communication with the n+ layer and forming a cathode;   f. a connection region extending between said first metallic area and said second metallic area, and placing said first metallic area and said second metallic area in electrical communication, wherein said connection region is formed by generating a hole in said wafer and filling said hole with conductive and insulating material.   
     
     
         39 . The photodiode of  claim 38  wherein said connection region comprises side walls and wherein said side walls are covered by a first insulating layer, a first conducting layer, and a second insulating layer. 
     
     
         40 . The photodiode of  claim 39  wherein the first insulating layer is an oxide. 
     
     
         41 . The photodiode of  claim 39  wherein the second insulating layer is an oxide. 
     
     
         42 . The photodiode of  claim 39  wherein the first conducting layer is doped poly-silicon. 
     
     
         43 . The photodiode of  claim 39  wherein the second insulating layer is in physical communication with a filler. 
     
     
         44 . The photodiode of  claim 43  wherein the filler is undoped poly-silicon. 
     
     
         45 . The photodiode of  claim 38  wherein said active region comprises a doped material of a n conductivity type. 
     
     
         46 . The photodiode of  claim 38  wherein said active region comprises a doped material of a p conductivity type. 
     
     
         47 . The photodiode of  claim 38  wherein said wafer is encircled by a metallic ring. 
     
     
         48 . The photodiode of  claim 47  wherein silicon underneath the metal ring is doped with an impurity of a selected conductivity type. 
     
     
         49 . A photodiode comprising:
 a. a silicon wafer having a front side and a back side, wherein said wafer has a thickness of 300 microns or less and wherein each of said front side and back side has a surface;   b. a p+ layer formed within said wafer and located proximate to said back side;   c. a n+ layer formed with said wafer and located proximate to said front side, wherein said p+ layer and said n+ layer are separated by an area and wherein said area comprises an active region;   d. a first metallic area formed on the front side surface, said first metallic area in electrical communication with the n+ layer and forming an cathode;   e. a second metallic area formed on the back side surface, said second metallic area in electrical communication with the p+ layer and forming an anode;   f. a connection region extending between said first metallic area and said second metallic area, and placing said first metallic area and said second metallic area in electrical communication, wherein said connection region is formed by generating a hole in said wafer and filling said hole with conductive and insulating material.   
     
     
         50 . The photodiode of  claim 49  wherein said connection region comprises side walls and wherein said side walls are covered by a first insulating layer, a first conducting layer, and a second insulating layer. 
     
     
         51 . The photodiode of  claim 50  wherein the first insulating layer is an oxide. 
     
     
         52 . The photodiode of  claim 50  wherein the second insulating layer is an oxide. 
     
     
         53 . The photodiode of  claim 50  wherein the first conducting layer is doped poly-silicon. 
     
     
         54 . The photodiode of  claim 50  wherein the second insulating layer is in physical communication with a filler. 
     
     
         55 . The photodiode of  claim 43  wherein the filler is undoped poly-silicon. 
     
     
         56 . The photodiode of  claim 49  wherein said active region comprises a doped material of a n conductivity type. 
     
     
         57 . The photodiode of  claim 49  wherein said active region comprises a doped material of a p conductivity type. 
     
     
         58 . The photodiode of  claim 49  wherein said wafer is encircled by a metallic ring.