Thin wafer detectors with improved radiation damage and crosstalk characteristics

Abstract

The present invention is directed toward a detector structure, detector arrays, and a method of detecting incident radiation. The present invention comprises several embodiments that provide for reduced radiation damage susceptibility, decreased affects of crosstalk, reduced dark current (current leakage) and increased flexibility in application. In one embodiment, a photodiode array comprises a substrate having at least a front side and a back side, a plurality of diode elements integrally formed in the substrate forming the array, wherein each diode element has a p+ fishbone pattern on the front side, and wherein the p+ fishbone pattern substantially reduces capacitance and crosstalk between adjacent photodiodes, a plurality of front surface cathode and anode contacts, and wire interconnects between diode elements made through a plurality of back surface contacts.

1 - 20 . (canceled) 
     
     
         21 . A diode element, having a center, comprising:
 a substrate having a front side and a back side;   at least two metal lines on said front side, wherein each of said metal lines has a first end and a second end;   a contiguous metallic interconnect, distinct from the at least two metal lines, wherein said contiguous metallic interconnect encircles said metal lines and is in physical communication with at least one of the first end or second end of each of said at least two metal lines;   at least two cathode pads surrounding said contiguous metallic interconnect; and   an anode pad positioned in said center of the diode elements.   
     
     
         22 . The diode element of  claim 21 , wherein said substrate comprises n doped silicon. 
     
     
         23 . The diode element of  claim 22 , wherein said n doped silicon substrate has a thickness ranging from 0.075 mm to 0.275 mm. 
     
     
         24 . The diode element of  claim 21 , wherein an n+ doped region and a p+-doped region are separated from an n+ layer by an active region. 
     
     
         25 . The diode element of  claim 21 , wherein said contiguous metallic interconnect and said at least two metal lines define a fishbone pattern. 
     
     
         26 . The diode element of  claim 25  wherein the at least two metal lines are p+ and are spaced from each other by a gap. 
     
     
         27 . The diode element of  claim 27  wherein the gap between the at least two p+ metal lines is in a range of 100 μm to 180 μm. 
     
     
         28 . The diode element of  claim 21  wherein the contiguous metallic interconnect and at least two cathode pads are separated by a gap in a range of 25 μm to  75 μm.    
     
     
         29 . The diode element of  claim 21 , further comprising an antireflective coating layer. 
     
     
         30 . The diode element of  claim 29 , wherein said antireflective coating layer is a thin film material. 
     
     
         31 . The diode element of  claim 30  wherein said thin film material is one of an oxide, a sulfide, a fluoride, a nitride, a selenide, or a metal. 
     
     
         32 . The diode element of  claim 29  wherein said antireflective coating is a silicon dioxide antireflective. 
     
     
         33 . A diode, having a center, comprising:
 a substrate having a front side and a back side;   at least two metal lines on said front side, wherein each of said metal lines has a first end and a second end;   a contiguous metallic interconnect, distinct from the at least two metal lines;   at least two cathode pads surrounding said contiguous metallic interconnect; and   an anode pad positioned in said center of the diode elements, wherein said contiguous metallic interconnect encircles said metal lines and said anode pad and wherein said contiguous metallic interconnect is in physical communication with at least one of the first end or second end of each of said at least two metal lines.   
     
     
         34 . The diode of  claim 33 , wherein said substrate comprises n doped silicon. 
     
     
         35 . The diode element of  claim 33 , wherein an n+ doped region and a p+-doped region are separated from an n+ layer by an active region. 
     
     
         36 . The diode of  claim 33 , wherein said contiguous metallic interconnect and said at least two metal lines define a fishbone pattern. 
     
     
         37 . The diode of  claim 34  wherein the at least two metal lines are p+ and are spaced from each other by a gap. 
     
     
         38 . The diode of  claim 37  wherein the gap between the at least two p+ metal lines is in a range of 100 μm to 180 μm. 
     
     
         39 . The diode of  claim 33  wherein the contiguous metallic interconnect and at least two cathode pads are separated by a gap in a range of 25 μm to 75 μm. 
     
     
         40 . The diode element of  claim 21 , further comprising an antireflective coating layer comprising at least one an oxide, a sulfide, a fluoride, a nitride, a selenide, or a metal.