Image sensors

Abstract

An image sensor includes a device isolation layer disposed in a substrate and defining pixel regions, and a grid pattern on a surface of the substrate. The grid pattern overlaps the device isolation layer between adjacent pixel regions in a direction perpendicular to the surface. The grid pattern has a width less than a width of the device isolation layer.

What is claimed is: 
     
         1 . An image sensor, comprising:
 a device isolation layer disposed in a substrate and defining pixel regions; and   a grid pattern over a surface of the substrate,   wherein the grid pattern overlaps the device isolation layer between adjacent pixel regions in a first direction perpendicular to the surface, the grid pattern having a width less than a width of the device isolation layer.   
     
     
         2 . The image sensor of  claim 1 , wherein the width of the grid pattern is substantially uniform along the first direction. 
     
     
         3 . The image sensor of  claim 1 , further comprising photoelectric conversion devices respectively over the pixel regions in the substrate,
 wherein the grid pattern is spaced apart from at least one of the photoelectric conversion devices along a second direction perpendicular to the first direction.   
     
     
         4 . The image sensor of  claim 3 , wherein at least a portion of the device isolation layer is exposed between the grid pattern and the at least one of the photoelectric conversion devices. 
     
     
         5 . The image sensor of  claim 1 , further comprising color filters disposed over the surface of the substrate and respectively provided over the pixel regions,
 wherein the grid pattern is disposed between adjacent color filters from among the color filters, the grid pattern having a height equal to or less than half a height of each of the color filters.   
     
     
         6 . The image sensor of  claim 1 , wherein the grid pattern comprises a lower grid, and an upper grid on the lower grid,
 the upper grid having a width substantially uniform along the first direction.   
     
     
         7 . The image sensor of  claim 6 , wherein the lower grid has a width greater than or equal to the width of the upper grid. 
     
     
         8 . The image sensor of  claim 1 , further comprising a refractive fence on the grid pattern,
 wherein the refractive fence has a refractive index less than a refractive index of the grid pattern.   
     
     
         9 . The image sensor of  claim 8 , wherein the refractive fence has a height greater than or equal to a height of the grid pattern. 
     
     
         10 . The image sensor of  claim 8 , wherein the refractive fence has a width greater than or equal to the width of the grid pattern. 
     
     
         11 . The image sensor of  claim 1 , wherein the width of the grid pattern is about 100 nm or less. 
     
     
         12 . The image sensor of  claim 1 , further comprising:
 color filters disposed over the surface of the substrate and respectively provided over the pixel regions; and   a planarization layer between the substrate and the color filter,   wherein the grid pattern is disposed in the planarization layer.   
     
     
         13 . An image sensor, comprising:
 a device isolation layer disposed in a substrate and defining pixel regions;   photoelectric conversion devices respectively over the pixel regions in the substrate; and   a grid pattern over a surface of the substrate and overlapping the device isolation layer in a first direction perpendicular to the surface,   wherein the grid pattern is spaced apart from at least one of the photoelectric conversion devices along a second direction perpendicular to the first direction.   
     
     
         14 . The image sensor of  claim 13 , wherein at least a portion of the device isolation layer is exposed between the grid pattern and the at least one of the photoelectric conversion devices. 
     
     
         15 . The image sensor of  claim 13 , wherein the grid pattern has a width substantially uniform along the first direction, the width of the grid pattern being less than a width of the device isolation layer. 
     
     
         16 . An image sensor, comprising:
 a substrate comprising an array of photoelectric conversion devices in respective pixel regions defined by a device isolation layer within the substrate, the device isolation layer having a lattice shape; and   a grid pattern over a surface of the substrate, the grid pattern having a lattice shape and overlapping the device isolation layer to partly cover the device isolation layer.   
     
     
         17 . The image sensor of  claim 16 , wherein a width of the grid pattern is less than a width of the device isolation layer. 
     
     
         18 . The image sensor of  claim 16 , further comprising color filters disposed over the surface of the substrate and respectively provided over the pixel regions,
 wherein the grid pattern is disposed between adjacent color filters from among the color filters, the grid pattern having a height equal to or less than half a height of each of the color filters.   
     
     
         19 . The image sensor of  claim 16 , further comprising a refractive fence on the grid pattern, the refractive fence having a refractive index less than a refractive index of the grid pattern. 
     
     
         20 . The image sensor of  claim 19 , wherein a width of the refractive index is greater than a width of the grid pattern.