Optimized light guide array for an image sensor

Abstract

An image sensor has a plurality of pixels in a pixel array. Each pixel includes a photoelectric conversion unit below an insulating layer and a light guide to transmit light to the photoelectric conversion unit. Across five or more pixels arrayed in a direction, the light guides have a spacing between them that varies non-monotonically across the five or more pixels. A width of the light guide and/or a horizontal pitch between consecutive light guides may vary non-monotonically across same. A light guide of a pixel that detects light of shorter wavelengths only may be narrower than a light guide of another pixel that detects light of longer wavelengths. A color filter may be coupled to the light guide. A width of a gap between consecutive color filters may vary non-monotonically across same. A pitch between the gaps may vary non-monotonically across same.

1 . An image sensor comprising a pixel array supported by a substrate, the pixel array comprising a plurality of pixels, each pixel comprising:
 a photoelectric conversion unit;   a light guide; and,   a color filter coupled to transmit light to said photoelectric conversion unit via said light guide,   wherein a gap exists between the color filters of each pair of consecutive pixels among five or more pixels arrayed side-by-side in a direction, the five or more pixels being among the plurality of pixels,   wherein the gap has a width, the width varying non-monotonically across the five or more pixels.   
     
     
         2 . The image sensor of  claim 1 , wherein the width alternates between increasing and decreasing across the five or more pixels. 
     
     
         3 . The image sensor of  claim 1 , wherein the width varies by 0.1 um or more across sixteen pixels arrayed side-by-side in the direction. 
     
     
         4 . The image sensor of  claim 3 , wherein the width alternates between increasing and decreasing across the five or more pixels. 
     
     
         5 . The image sensor of  claim 3 , wherein the color filter comprises a colorant. 
     
     
         6 . The image sensor of  claim 1 , wherein the width varies by 0.2 um or more across sixteen pixels arrayed side-by-side in the direction. 
     
     
         7 . The image sensor of  claim 6 , wherein the width alternates between increasing and decreasing across the five or more pixels. 
     
     
         8 . The image sensor of  claim 6 , wherein the color filter comprises a colorant.