High Fill-Factor Laser-Treated Semiconductor Device on Bulk Material with Single Side Contact Scheme

Abstract

The present disclosure provides systems and methods for configuring and constructing a single photo detector or array of photo detectors with all fabrications circuitry on a single side of the device. Both the anode and the cathode contacts of the diode are placed on a single side, while a layer of laser treated semiconductor is placed on the opposite side for enhanced cost-effectiveness, photon detection, and fill factor.

1 . A photosensing device, comprising:
 a semiconductor material having a first side and a second side;   a first region doped with a first dopant and disposed on said first side;   a second region doped with a second dopant and disposed on said second side;   a textured region formed within said first side such that the textured region is electrically coupled to at least the first doped region or the second doped region.   
     
     
         2 . The photosensing device of  claim 1 , wherein the textured region is formed via a pulsed laser process. 
     
     
         3 . The photosensing device of  claim 1 , wherein the textured region is formed near a depletion region. 
     
     
         4 . The photosensing device of  claim 1 , further comprising a third region doped with a third dopant and disposed on said second side of the semiconductor material. 
     
     
         5 . The photosensing device of  claim 1 , wherein the textured region is doped with said first dopant. 
     
     
         6 . The photosensing device of  claim 1 , wherein the semiconductor material is comprised of silicon. 
     
     
         7 . The photosensing device of  claim 1 , further comprising a passivation layer disposed on said first side. 
     
     
         8 . The photosensing device of  claim 1 , further comprising a passivation layer disposed on said second side. 
     
     
         9 . The photosensing device of  claim 6 , wherein said passivation layer is selected from the group consisting of oxides, nitrides, metals and semiconductors. 
     
     
         10 . The photosensing device of  claim 1 , wherein the semiconductor material and said textured region are doped with a p-type dopant. 
     
     
         11 . The photosensing device of  claim 1 , wherein the semiconductor material and said textured region are doped with an n-type dopant. 
     
     
         12 . The photosensing device of  claim 4 , wherein the third dopant is opposite in polarity of the second dopant. 
     
     
         13 . The photosensing device of  claim 1 , wherein the device is operated at a bias of less than about 5V. 
     
     
         14 . The photosensing device of  claim 1 , wherein the semiconductor material has a thickness of
 less than about 500 μm.   
     
     
         15 . The photo sensing device of  claim 1 , wherein the semiconductor material has a thickness of less than about 50 μm. 
     
     
         16 . The photosensing device of  claim 1 , wherein the textured region extends into the semiconductor material to a depth of less than about 2 μm. 
     
     
         17 . The device of  claim 1 , wherein the first side is opposite of incident radiation such that radiation penetrates the second side prior to contacting the textured region. 
     
     
         18 . A photosensing device, comprising:
 a semiconductor material with a first and a second side;   a textured region doped with a first dopant and disposed on the first side of the semiconductor material;   a first ohmic contact disposed on the second side of the semiconductor material and in electrical contact with a region doped with a second dopant, the region being electrically coupled with the textured region; and   a second ohmic contact disposed on the second side of the semiconductor material in electrical contact with the textured region via the semiconductor material.   
     
     
         19 . The device of  claim 18 , wherein the semiconductor material is comprised of silicon. 
     
     
         20 . The device of  claim 18 , wherein the device exhibits a quantum efficiency greater than 80% for light wavelengths longer than 900 nm and the device has a material thickness less than 500 μm. 
     
     
         21 . The device of  claim 18 , wherein the device exhibits a quantum efficiency greater than 80% for light wavelengths longer than 900 nm and the device has a material thickness less than 100 μm. 
     
     
         22 . The device of  claim 18 , wherein the device exhibits a quantum efficiency greater than 80% for light wavelengths longer than 900 nm and the device has a material thickness less than 50 μm. 
     
     
         23 . The device of  claim 18 , wherein the device exhibits an absorptance greater than 80% for light wavelengths longer than 800 nm and has a material thickness less than 100 μm. 
     
     
         24 . The device of  claim 18 , wherein the device is disposed such that light radiation is directly incident on the textured region on the first side of the semiconductor material. 
     
     
         25 . The device of  claim 18 , wherein the region doped with a second dopant is electrically coupled with the textured region thereby forming a diode. 
     
     
         26 . A photosensing image sensor comprising:
 an array of pixels having a first doped region with a first dopant, a second doped region with a second dopant, and a textured region electrically coupled to the second doped region; and   a trench isolation featured formed between the array of pixels to isolate the array of pixels.   
     
     
         27 . The photosensing image sensor of  claim 26 , wherein the trench isolation feature electrically isolates the array of pixels. 
     
     
         28 . The photosensing image sensor of  claim 26 , wherein the trench isolation feature optically isolates the array of pixels. 
     
     
         29 . The photosensing image sensor of  claim 26 , wherein the textured region is formed via a pulsed laser process. 
     
     
         30 . The photosensing image sensor of  claim 26 , wherein the imager has a fill factor greater than 80%. 
     
     
         31 . The photosensing image sensor of  claim 26 , wherein the first sides of the plurality of photosensing devices are disposed to form a substantially planar top surface exposed to incident radiation. 
     
     
         32 . The photosensing image sensor of  claim 26 , wherein the textured regions have a surface area that is greater than about 80% of the total top surface area.