Photodetector

Abstract

A sensor includes a first substrate including at least a first pixel. The first pixel includes an avalanche photodiode to convert incident light into electric charge and includes an anode and a cathode. The cathode is in a well region of the first substrate. The first pixel includes an isolation region that isolates the well region from at least a second pixel that is adjacent to the first pixel. The first pixel includes a hole accumulation region between the isolation region and the well region. The hole accumulation region is electrically connected to the anode.

What is claimed is: 
     
         1 . A sensor, comprising:
 an on-chip lens;   a first substrate including:
 a first semiconductor substrate including a first avalanche photodiode, wherein the first avalanche photodiode includes a cathode region and an anode region; 
 a first wiring layer including a first wiring and a second wiring; 
   a second substrate stacked on the first substrate, the second substrate including:
 a second semiconductor substrate including a circuit; 
 a second wiring layer including a third wiring and a fourth wiring, 
   wherein the first avalanche photodiode is disposed between the on-chip lens and the first wiring layer,
 wherein light incident on the on-chip lens is passed to the first avalanche photodiode, 
 wherein the on-chip lens overlaps at least one of the cathode region and the anode region, 
 wherein the cathode region is electrically connected to the first wiring and the anode region is electrically connected to the second wiring, 
 wherein the first wiring is directly bonded to the third wiring, and 
   wherein the second wiring is directly bonded to the fourth wiring.   
     
     
         2 . The sensor according to  claim 1 , wherein the first avalanche photodiode is configured as a backside illumination type pixel. 
     
     
         3 . The sensor according to  claim 1 , wherein the third wiring is electrically connected to the circuit. 
     
     
         4 . The sensor according to  claim 1 , wherein the fourth wiring is electrically connected to the circuit. 
     
     
         5 . The sensor according to  claim 1 , wherein the on-chip lens at least partially overlaps the cathode region. 
     
     
         6 . The sensor according to  claim 1 , wherein the on-chip lens at least partially overlaps the anode region. 
     
     
         7 . The sensor according to  claim 1 , wherein the on-chip lens at least partially overlaps the first wiring. 
     
     
         8 . The sensor according to  claim 1 , wherein the on-chip lens at least partially overlaps the second wiring. 
     
     
         9 . The sensor according to  claim 1 , wherein the first semiconductor substrate includes a second avalanche photodiode and an isolation region, wherein the isolation region is disposed between the first avalanche photodiode and the second avalanche photodiode. 
     
     
         10 . A sensor, comprising:
 an on-chip lens;   a first substrate including:
 a first semiconductor substrate including a first avalanche photodiode, wherein the first avalanche photodiode includes a first semiconductor region and a second semiconductor region; 
 a first wiring layer including a first wiring; 
   a second substrate stacked on the first substrate, the second substrate including:
 a second semiconductor substrate including a circuit; 
 a second wiring layer including a second wiring, 
   wherein the first avalanche photodiode is disposed between the on-chip lens and the first wiring layer,
 wherein light incident on the on-chip lens is passed to the first avalanche photodiode, 
 wherein the first semiconductor region is electrically connected to the first wiring and the circuit is electrically connected to the second wiring, 
 wherein the first wiring is directly bonded to the second wiring, 
   wherein the on-chip lens overlaps the first semiconductor region, and
 wherein a conductivity type of the first semiconductor region is different from a conductivity type of the second semiconductor region. 
   
     
     
         11 . The sensor according to  claim 10 , wherein the first avalanche photodiode is configured as a backside illumination type pixel. 
     
     
         12 . The sensor according to  claim 10 , wherein the first semiconductor region is configured as a cathode and the second semiconductor region is configured as an anode. 
     
     
         13 . The sensor according to  claim 10 , wherein the on-chip lens overlaps the first wiring. 
     
     
         14 . The sensor according to  claim 10 , wherein the on-chip lens at least partially overlaps the second semiconductor region. 
     
     
         15 . The sensor according to  claim 10 , wherein the first avalanche photodiode is electrically connected to the circuit via the first wiring and the second wiring. 
     
     
         16 . The sensor according to  claim 10 , wherein the first semiconductor substrate includes a second avalanche photodiode and an isolation region, wherein the isolation region is disposed between the first avalanche photodiode and the second avalanche photodiode. 
     
     
         17 . The sensor according to  claim 10 , wherein the conductivity type of the first semiconductor region is n-type and the conductivity type of the second semiconductor region is p-type. 
     
     
         18 . A sensor, comprising:
 an on-chip lens;   a first substrate including:
 a first semiconductor substrate including a first avalanche photodiode, wherein the first avalanche photodiode includes a first semiconductor region and a second semiconductor region; 
 a first wiring layer including a first wiring; 
   a second substrate stacked on the first substrate, the second substrate including:
 a second semiconductor substrate including a circuit; 
 a second wiring layer including a second wiring, 
   wherein the first avalanche photodiode is disposed between the on-chip lens and the first wiring layer,
 wherein light incident on the on-chip lens is passed to the first avalanche photodiode, 
 wherein the first semiconductor region is electrically connected to the first wiring, 
   wherein the on-chip lens overlaps the first semiconductor region, and
 wherein a conductivity type of the first semiconductor region is different from a conductivity type of the second semiconductor region. 
   
     
     
         19 . The sensor according to  claim 18 , wherein the first avalanche photodiode is configured as a backside illumination type pixel. 
     
     
         20 . The sensor according to  claim 18 , wherein the first semiconductor region is configured as a cathode and the second semiconductor region is configured as an anode. 
     
     
         21 . The sensor according to  claim 18 , wherein the second wiring layer is disposed between the first semiconductor substrate and the second semiconductor substrate. 
     
     
         22 . The sensor according to  claim 18 , wherein the first avalanche photodiode is electrically connected to the circuit via the first wiring. 
     
     
         23 . The sensor according to  claim 18 , wherein the circuit is electrically connected to the first avalanche photodiode via the second wiring. 
     
     
         24 . The sensor according to  claim 18 , wherein the first semiconductor region outputs a pixel signal based on the light and the first semiconductor region is disposed in a center portion of the first avalanche photodiode. 
     
     
         25 . The sensor according to  claim 18 , wherein the conductivity type of the first semiconductor region is n-type and the conductivity type of the second semiconductor region is p-type. 
     
     
         26 . A sensor, comprising:
 an on-chip lens;   a first semiconductor substrate including a first avalanche photodiode, wherein the first avalanche photodiode includes a first semiconductor region and a second semiconductor region;   a first wiring layer including a first wiring,   wherein the first avalanche photodiode is disposed between the on-chip lens and the first wiring layer,
 wherein light incident on the on-chip lens is passed to the first avalanche photodiode, 
 wherein the first semiconductor region is electrically connected to the first wiring, 
   wherein the on-chip lens overlaps the first semiconductor region, and
 wherein a conductivity type of the first semiconductor region is different from a conductivity type of the second semiconductor region. 
   
     
     
         27 . The sensor according to  claim 26 , wherein the first avalanche photodiode is configured as a backside illumination type pixel. 
     
     
         28 . The sensor according to  claim 26 , wherein the first semiconductor region is configured as a cathode and the second semiconductor region is configured as an anode. 
     
     
         29 . The sensor according to  claim 26 , wherein the first semiconductor region outputs a pixel signal based on the light and the first semiconductor region is disposed in a center portion of the first avalanche photodiode. 
     
     
         30 . The sensor according to  claim 26 , wherein the conductivity type of the first semiconductor region is n-type and the conductivity type of the second semiconductor region is p-type.