Image sensor with dual layer photodiode structure

Abstract

An image system with a dual layer photodiode structure is provided for processing color images. In particular, the image system can include an image sensor that can include photodiodes with a dual layer photodiode structure. In some embodiments, the dual layer photodiode can include a first layer of photodiodes (e.g., a bottom layer), an insulation layer disposed on the first layer of photodiodes, and a second layer of photodiodes (e.g., a top layer) disposed on the insulation layer. The first layer of photodiodes can include one or more suitable pixels (e.g., green, blue, clear, luminance, and/or infrared pixels). Likewise, the second layer of photodiodes can include one or more suitable pixels (e.g., green, red, clear, luminance, and/or infrared pixels). An image sensor incorporating dual layer photodiodes can gain light sensitivity with additional clear pixels and maintain luminance information with green pixels.

1 . A plurality of photodiodes for receiving light, the plurality of photodiodes comprising:
 a bottom layer of photodiodes;   a top layer of photodiodes, wherein at least one pixel in the top layer of photodiodes has a different spectral response than a pixel at the same position in the bottom layer of photodiodes; and   an insulation layer disposed between the bottom layer of the photodiodes and the top layer of the photodiodes.   
     
     
         2 . The plurality of photodiodes of  claim 1 , wherein the bottom layer of the photodiodes comprises a bottom pixel at a first position, and wherein the top layer of the photodiodes comprises a top pixel stacked on top of the bottom pixel at the first position. 
     
     
         3 . The plurality of photodiodes of  claim 2 , wherein the bottom pixel is a red pixel and the top pixel is a blue pixel. 
     
     
         4 . The plurality of photodiodes of  claim 2 , wherein the bottom pixel is a first green pixel and the top pixel is a second green pixel. 
     
     
         5 . The plurality of photodiodes of  claim 2 , wherein the bottom pixel is a first clear pixel and the top pixel is a second clear pixel. 
     
     
         6 . The plurality of photodiodes of  claim 2 , wherein the bottom pixel is a first luminance pixel and the top pixel is a second luminance pixel. 
     
     
         7 . The plurality of photodiodes of  claim 2 , wherein the bottom pixel is a first infrared pixel and the top pixel is a second infrared pixel. 
     
     
         8 . The plurality of photodiodes of  claim 2 , wherein the bottom pixel is an infrared pixel and the top pixel is one of a color pixel, a clear pixel, or a luminance pixel. 
     
     
         9 . The plurality of photodiodes of  claim 1 , wherein the first array of the photodiodes and the second array of the photodiodes are arranged in an adamantine pattern. 
     
     
         10 . The plurality of photodiodes of  claim 1 , wherein the bottom layer of the photodiodes and the top layer of the photodiodes are arranged in a rectilinear pattern, wherein at least one line of the bottom layer and the top layer comprises a plurality of pixels of the same color. 
     
     
         11 . The plurality of photodiodes of  claim 10 , wherein the at least one line is at least one row or at least one column. 
     
     
         12 . The plurality of photodiodes of  claim 1 , wherein the bottom layer, the insulation layer, and the top layer have a pre-determined orientation. 
     
     
         13 . The plurality of photodiodes of  claim 1 , wherein the pre-determined orientation is 45°. 
     
     
         14 . An image sensor, the image sensor comprising:
 a plurality of photodiodes with a dual layer photodiode pixel structure; and   an infrared (“IR”) cutoff filter, wherein the IR cutoff filter is positioned over at least a portion of the plurality of photodiodes.   
     
     
         15 . The image sensor of  claim 14 , further comprising a color filter array (“CFA”), and wherein the CFA comprises one or more of a magenta filter element and a green filter element. 
     
     
         16 . The image sensor of  claim 14 , wherein the plurality of photodiodes comprises one or more infrared pixels, and wherein the IR cutoff filter covers the one or more infrared pixels. 
     
     
         17 . The image sensor of  claim 14 , wherein the plurality of photodiodes comprises one or more color pixels and one or more clear pixels. 
     
     
         18 . The image sensor of  claim 17 , wherein the IR cutoff filter covers only the one or more color pixels. 
     
     
         19 . The image sensor of  claim 14 , wherein the dual layer photodiode pixel structure comprises a bottom layer of photodiodes and a top layer of photodiodes. 
     
     
         20 . The image sensor of  claim 19 , wherein the bottom layer comprises a set of red pixels at one or more positions and the top layer comprises a set of blue pixels stacked on top of the set of red pixels at the one or more positions. 
     
     
         21 . The image sensor of  claim 19 , wherein the bottom layer comprises a set of green pixels at one or more positions and the top layer comprises a set of blue pixels stacked on top of the set of green pixels at the one or more positions. 
     
     
         22 . The image sensor of  claim 19 , wherein the bottom layer comprises a set of red pixels at one or more positions and the top layer comprises a set of green pixels stacked on top of the set of red pixels at the one or more positions. 
     
     
         23 . The image sensor of  claim 19 , wherein the bottom layer comprises a set of red pixels and a first set of clear pixels, and the top layer comprises a set of blue pixels and a second set of clear pixels. 
     
     
         24 . The image sensor of  claim 19 , wherein the bottom layer comprises a set of red pixels and a first set of green pixels, and the top layer comprises a set of blue pixels and a second set of green pixels. 
     
     
         25 . The image sensor of  claim 19 , wherein the bottom layer comprises a set of red pixels, a first set of green pixels, and a first set of clear pixels, and the top layer comprises a set of blue pixels, a second set of green pixels, and a second set of clear pixels. 
     
     
         26 . The image sensor of  claim 14  further comprising at least one photodiode with a single layer photodiode pixel structure, wherein the plurality of photodiodes is positioned adjacent to the at least one photodiode. 
     
     
         27 . A method for binning a plurality of photodiodes, the method comprising:
 binning a set of first color pixels of the plurality of photodiodes along a first direction to form a first pixel group, wherein the plurality of photodiodes comprises a dual layer photodiode pixel structure;   binning a set of second color pixels and third color pixels of the plurality of photodiodes along a second direction to form a second pixel group;   combining the first pixel group and the second pixel group to form a binned pixel cluster; and   interpolating the binned pixel cluster to output a pixel image.   
     
     
         28 . The method of  claim 27 , wherein the dual layer photodiode pixel structure is arranged in an adamantine pixel arrangement. 
     
     
         29 . The method of  claim 27 , wherein the first color pixels are green pixels, the second color pixels are blue pixels, and the third color pixels are red pixels. 
     
     
         30 . The method of  claim 27 , wherein the pixel image comprises a rectilinear grid. 
     
     
         31 . The method of  claim 27 , wherein the first direction is orthogonal to the second direction. 
     
     
         32 . The method of  claim 27 , wherein the first direction is along a horizontal direction and the second direction is along a vertical direction. 
     
     
         33 . The method of  claim 27 , wherein the first direction is along a −45° direction and the second direction is along 45° direction.