Photosensitive imaging devices and associated methods

Abstract

Photosensitive devices and associated methods are provided. In one aspect, for example, a photosensitive imager device can include a semiconductor substrate having multiple doped regions forming at least one junction, a textured region coupled to the semiconductor substrate and positioned to interact with electromagnetic radiation, and an electrical transfer element coupled to the semiconductor substrate and operable to transfer an electrical signal from the at least one junction. In one aspect, the textured region is operable to facilitate generation of an electrical signal from the detection of infrared electromagnetic radiation. In another aspect, interacting with electromagnetic radiation further includes increasing the semiconductor substrate's effective absorption wavelength as compared to a semiconductor substrate lacking a textured region.

1 - 28 . (canceled) 
     
     
         29 . A photosensitive imager pixel, comprising:
 a semiconductor substrate having a radiation-receiving surface for receiving incident electromagnetic radiation and multiple doped regions forming at least one junction,   a textured region associated with the semiconductor substrate and positioned to receive at least a portion of the incident electromagnetic radiation and interact with said received electromagnetic radiation to cause at least a portion of said electromagnetic radiation to experience multiple passes within said semiconductor substrate so as to enhance quantum efficiency of said imager device, and   an electrical transfer element coupled to the semiconductor substrate and operable to transfer an electrical signal generated in response to absorption of the electromagnetic radiation within said semiconductor substrate.   
     
     
         30 . The photosensitive imager pixel of  claim 29 , wherein said semiconductor substrate comprises said textured region. 
     
     
         31 . The photosensitive imager pixel of  claim 29 , wherein said textured region is coupled to a surface opposite the radiation-receiving surface. 
     
     
         32 . The photosensitive imager pixel of  claim 31 , wherein said surface opposite the radiation-receiving surface comprises said textured region. 
     
     
         33 . The photosensitive imager pixel of  claim 31 , further comprising an additional textured region coupled to said radiation-receiving surface of said semiconductor substrate. 
     
     
         34 . The photosensitive imager pixel of  claim 29 , wherein said textured region is coupled to said radiation-receiving surface of said semiconductor substrate. 
     
     
         35 . The photosensitive imager pixel of  claim 29 , wherein said textured region comprises surface features selected from the group consisting of cones, pillars, pyramids, microlenses, quantum dots, inverted features, and combinations thereof. 
     
     
         36 . The photosensitive imager pixel of  claim 35 , wherein said surface features have a size in a range of about 50 nm to about 20 microns. 
     
     
         37 . The photosensitive imager pixel of  claim 29 , wherein said incident electromagnetic radiation comprises infrared radiation having a wavelength in a range of about 800 nm to about 1300 nm. 
     
     
         38 . The photosensitive imager pixel of  claim 29 , wherein said transfer element is selected from the group consisting of a transistor, a sensing node, a transfer gate, and combinations thereof. 
     
     
         39 . The photosensitive imager pixel of  claim 29 , further comprising a lens optically coupled to said radiation-receiving surface and positioned to focus the incident electromagnetic radiation into the semiconductor substrate. 
     
     
         40 . The photosensitive imager pixel of  claim 29 , wherein a side surface of said semiconductor substrate comprises said textured region. 
     
     
         41 . The photosensitive imager pixel of  claim 29 , wherein said semiconductor substrate comprises silicon. 
     
     
         42 . A photosensitive imager array, comprising:
 at least two neighboring photosensitive pixels, each of said photosensitive pixels comprising:
 a semiconductor substrate having a radiation-receiving surface for receiving incident electromagnetic radiation and multiple doped regions forming at least one junction, and 
 a textured region coupled to the semiconductor substrate and positioned to receive at least a portion of the incident electromagnetic radiation and to interact with said received electromagnetic radiation to cause any of diffusion and redirection of the electromagnetic radiation so as to enhance the semiconductor substrate's effective absorption length and increase the photosensitive imager's quantum efficiency; and 
   an electrical transfer element coupled to the semiconductor substrate and operable to transfer an electrical signal generated in response to absorption of the electromagnetic radiation within said semiconductor substrate.   
     
     
         43 . The photosensitive imager array of  claim 42 , wherein the textured region of each of said photosensitive pixels is configured to cause at least a portion of the incident electromagnetic radiation entering the semiconductor substrate to experience multiple passes within the semiconductor substrate. 
     
     
         44 . The photosensitive imager array of  claim 42 , wherein said textured region is coupled to a surface opposite to said radiation-receiving surface. 
     
     
         45 . The photosensitive imager array of  claim 42 , wherein said surface opposite said radiation-receiving surface comprises said textured region. 
     
     
         46 . The photosensitive imager array of  claim 42 , wherein at least one of said photosensitive pixels comprises an additional textured region. 
     
     
         47 . The photosensitive imager array of  claim 42 , wherein said textured region is coupled to said radiation-receiving surface of said semiconductor substrate. 
     
     
         48 . The photosensitive imager array of  claim 42 , wherein said incident electromagnetic radiation comprises infrared radiation having a wavelength in a range of about 800 nm to about 1300 nm.