Method of manufacturing image sensor for reducing crosstalk characteristic

Abstract

An image sensor includes a plurality of photoelectric detectors, a plurality of color filters, and at least one pixel isolation region between adjacent ones of the photoelectric detectors. The color filters include a white color filter, and the color filters correspond to respective ones of the photoelectric detectors. The at least one pixel isolation region serves to physically and at least partially optically separate the photoelectric detectors from one another.

What is claimed is: 
     
       1. A method of manufacturing an image sensor, comprising:
 providing a semiconductor substrate, the semiconductor substrate including a semiconductor material; 
 forming a photoelectric detector layer on the semiconductor substrate by implanting impurities through a surface of the semiconductor substrate; 
 forming at least one trench in the photoelectric detector layer to a predetermined depth; 
 filling the at least one trench with an insulating material to form at least one isolation region, such that the at least one isolation region includes a high-k material, and top surfaces of the at least one isolation region and the photoelectric detector layer are level with each other; 
 forming at least one of an anti-reflection layer and a caption layer on the top surfaces of the at least one isolation region and the photoelectric detector layer, such that the anti-reflection layer includes multiple layers in which materials having different refractive indexes are stacked; 
 forming a color filter layer on the photoelectric detector layer and the at least one isolation region at least one of the anti-reflection layer and the caption layer, the color filter layer including a white filter and at least one of a red filter, a green filter, or a blue filter; and 
 forming microlenses on the color filter layer, 
 wherein the semiconductor substrate and the color filter layer are on opposite sides of the photoelectric detector layer, a wiring unit within the semiconductor substrate being connected to the photoelectric detector layer, 
 wherein the color filter layer includes a plurality of four by four (4×4) color filter arrays, and 
 wherein in each of the plurality of 4×4 color filter arrays, a ratio of the red filter or the blue filter to the white filter is 1:2.  
 
     
     
       2. The method as claimed in  claim 1 , wherein forming the at least one trench includes etching the photoelectric detector layer in a direction of the semiconductor substrate. 
     
     
       3. The method as claimed in  claim 2 , wherein forming the at least one trench includes etching the photoelectric detector layer so that a height of the at least one trench is substantially equal to a height of the photoelectric detector layer and so that a surface of the semiconductor substrate is exposed. 
     
     
       4. The method as claimed in  claim 2 , wherein forming the at least one trench includes etching the photoelectric detector layer so that a bottom of the at least one trench is higher than a bottom of the photoelectric detector layer. 
     
     
       5. The method as claimed in  claim 1 , wherein the at least one trench is between adjacent photoelectric detectors in the photoelectric detector layer. 
     
     
       6. The method as claimed in  claim 5 , wherein the white filter and at least one of the red filter, green filter, and blue filter correspond to the photoelectric detectors, respectively. 
     
     
       7. The method as claimed in  claim 1 , further comprising: wherein forming an the anti-reflection layer is before forming the color filter layer. 
     
     
       8. The method as claimed in  claim 1 , wherein the insulating material has a refractive index different from a refractive index of the photoelectric detector layer. 
     
     
       9. The method as claimed in  claim 8 , further comprising: forming a polysilicon layer inside the at least one trench. 
     
     
       10. The method as claimed in  claim 1 , wherein the microlenses correspond to the white filter and at least one of the red filter, green filter, or blue filter, respectively. 
     
     
       11. The method as claimed in claim 1, wherein the isolation region includes a material having a permittivity greater than that of silicon oxide.  
     
     
       12. The method as claimed in claim 1, wherein the isolation region includes a material having a refractive index less than silicon oxide.  
     
     
       13. The method as claimed in claim 1, wherein a depth of the isolation region is less than a height of the photoelectric detecting layer, such that the isolation region is spaced apart from the semiconductor substrate.  
     
     
       14. The method as claimed in claim 1, wherein a depth of the isolation region is the same as a height of the photoelectric detecting layer, such that the isolation region contacts the semiconductor substrate.  
     
     
       15. The method as claimed in claim 1, wherein a depth of the trench is in a range of 2 μm to 3 μm.  
     
     
       16. The method as claimed in claim 1, wherein the stacked layer includes a first layer and a second layer, at least one of the first layer and the second layer including an oxide.  
     
     
       17. The method as claimed in claim 1, wherein the photoelectric detector layer includes N-type impurities.  
     
     
       18. The method as claimed in claim 1, wherein the isolation region includes an insulating layer and a polysilicon layer surrounded by the insulating layer.  
     
     
       19. An image sensor comprising:
 a pixel array including a plurality of unit pixels,   wherein each of the plurality of unit pixels includes:
 a plurality of photoelectric detectors including a first photoelectric detector and a second photoelectric detector; 
 a plurality of isolation regions including a first isolation region that is disposed between the first photoelectric detector and the second photoelectric detector, top surfaces of the first isolation region and the first and second photoelectric detectors being level with each other; 
 an anti-reflection layer disposed on the top surfaces of the first isolation region and the first and second photoelectric detectors, and including a first layer and a second layer disposed on the first layer; 
 a plurality of color filters disposed on the anti-reflection layer; and 
 a plurality of microlenses disposed on the plurality of color filters, 
   wherein the anti-reflection layer includes multiple layers in which materials having different refractive indexes are stacked,   wherein the plurality of color filters include a white filter, the plurality of color filters further include at least one of a red filter, a green filter and a blue filter,   wherein the first isolation region includes a high-k material, and   wherein the plurality of color filters include a plurality of four by four (4×4) color filter arrays, in each of the plurality of 4×4 color filter arrays, a ratio of the red filter or the blue filter to the white filter is 1:2.    
     
     
       20. The image sensor of claim 19, wherein each of the plurality of two by two unit pixels includes two yellow filters, one red filter, and one blue filter.  
     
     
       21. The image sensor of claim 19, wherein each of the plurality of unit pixels includes two white filters, one red filter and one blue filter.  
     
     
       22. The image sensor of claim 19, wherein the plurality of photoelectric detectors are separated from each other by the plurality of isolation regions.  
     
     
       23. The image sensor of claim 19, wherein a height of the first isolation region is the same as a height of the first photoelectric detector.  
     
     
       24. The image sensor of claim 19, wherein a height of the first isolation region is less than a height of the first photoelectric detector.  
     
     
       25. The image sensor of claim 19, wherein each of the plurality of isolation regions include an insulating layer and a polysilicon layer surrounded by the insulating layer.  
     
     
       26. The image sensor of claim 19, further comprising a caption layer on the plurality of isolation regions and the plurality of photoelectric detectors.  
     
     
       27. The image sensor of claim 19, wherein at least one of the first layer and the second layer includes oxide.  
     
     
       28. The image sensor of claim 19, wherein a height of the first isolation region is in a range of 2 to 3 μm.  
     
     
       29. An image sensor comprising:
 a pixel array including a plurality of unit pixels;   a row driver configured to provide a row control signal to the pixel array;   a correlated double sampler configured to receive a first signal from the pixel array and perform a sampling operation on the first signal;   a ramp generator configured to provide a reference voltage to the correlated double sampler; and   a timing controller configured to provide a control signal to the row driver and/or the correlated double sampler,   wherein each of the plurality of unit pixels includes:
 a plurality of photoelectric detectors including a first photoelectric detector and a second photoelectric detector; 
 a plurality of isolation regions including a first isolation region that is disposed between the first photoelectric detector and the second photoelectric detector, top surfaces of the first isolation region and the first and second photoelectric detectors being level with each other; 
 an anti-reflection layer disposed on the top surfaces of the first isolation region and the first and second photoelectric detectors, and including a first layer and a second layer disposed on the first layer, at least one of the first layer and the second layer including oxide; 
 a plurality of filters disposed on the anti-reflection layer and including at least one of a white filter, a yellow filter and a transparent filter, the plurality of filters further including at least one of a red filter, a green filter and a blue filter; and 
 a plurality of microlenses disposed on the plurality of filters, 
 wherein the plurality of color filters include a plurality of four by four (4×4) color filter arrays, in each of the plurality of 4×4 color filter arrays, a ratio of the red filter or the blue filter to the white filter is 1:2, and 
 wherein the anti-reflection layer includes multiple layers in which materials having different refractive indexes are stacked.  
   
     
     
       30. The image sensor of claim 29, wherein the plurality of filters include the white filter, the red filter and the blue filter.  
     
     
       31. The image sensor of claim 29, wherein the plurality of filters include the yellow filter, the red filter and the blue filter.  
     
     
       32. The image sensor of claim 29, wherein the plurality of filters include at least one of the red filter and the blue filter,
 the plurality of filters do not include the green filter, and   the plurality of filters include either two yellow filters or two white filters.    
     
     
       33. The image sensor of claim 29, further comprising a caption layer disposed on the plurality of isolation regions and the plurality of photoelectric detectors.  
     
     
       34. The image sensor of claim 29, wherein a height of the first isolation region is in a range of 2 to 3 μm.  
     
     
       35. An image sensor comprising:
 a pixel array including:
 a plurality of photoelectric detectors including a first photoelectric detector and a second photoelectric detector; 
 a plurality of isolation regions including a first isolation region that is disposed between the first photoelectric detector and the second photoelectric detector, top surfaces of the first isolation region and the first and second photoelectric detectors being level with each other; 
 an anti-reflection layer disposed on the top surfaces of the first isolation region and the first and second photoelectric detectors, and including a first layer and a second layer disposed on the first layer; 
 a plurality of color filters disposed on the anti-reflection layer; and 
 a plurality of microlenses disposed on the plurality of color filters, 
   wherein the anti-reflection layer includes multiple layers in which materials having different refractive indexes are stacked,   wherein the plurality of color filters include a yellow filter, the plurality of color filters further include at least one of a red filter, a green filter and a blue filter,   wherein the first isolation region includes a high-k material,   wherein at least one of the first layer and the second layer includes oxide, and   wherein the plurality of color filters include a plurality of four by four (4×4) color filter arrays, in each of the plurality of 4×4 color filter arrays, a ratio of the red filter or the blue filter to the yellow filter is 1:2.    
     
     
       36. The image sensor of claim 35, wherein a height of the first isolation region is in a range of 2 to 3 μm.  
     
     
       37. The method as claimed in claim 1, wherein each of the plurality of 4×4 color filter arrays includes a two by two (2×2) color filter array having two white filters, one red filter, and one blue filter.  
     
     
       38. The method as claimed in claim 1, wherein the color filter layer includes a yellow filter.