Image sensor

Abstract

An image sensor includes a plurality of groups of autofocus sensor units. Each of the groups of autofocus sensor units includes a plurality of sensing portions, a color filter layer disposed on the sensing portions, and a plurality of micro-lenses disposed on the color filter layer and correspondingly above the plurality of sensing portions. The image sensor includes a top film disposed conformally on the plurality of micro-lenses. A joint seam between the micro-lenses within one of the groups of autofocus sensor units has a first depth. A gap between the micro-lenses of the plurality of groups of autofocus sensor units has a second depth. The second depth is larger than the first depth.

What is claimed is: 
     
         1 . An image sensor, comprising:
 a plurality of groups of autofocus sensor units;   wherein each of the groups of autofocus sensor units comprises a plurality of sensing portions, a color filter layer disposed on the sensing portions, and a plurality of micro-lenses disposed on the color filter layer and correspondingly above the plurality of sensing portions;   a top film disposed conformally on the plurality of micro-lenses;   a joint seam between the micro-lenses within one of the groups of autofocus sensor units has a first depth; and   a gap between the micro-lenses of the plurality of groups of autofocus sensor units has a second depth, wherein the second depth is larger than the first depth.   
     
     
         2 . The image sensor of  claim 1 , wherein the plurality of sensing portions are embedded within a substrate. 
     
     
         3 . The image sensor of  claim 2 , wherein the substrate further comprises a plurality of deep trench isolation structures separating the plurality of sensing portions. 
     
     
         4 . The image sensor of  claim 1 , further comprises a partition grid structure within the color filter layer, wherein the partition grid structure separates each of the groups of autofocus sensor units. 
     
     
         5 . The image sensor of  claim 4 , further comprises a light shielding structure embedded within the partition grid structure. 
     
     
         6 . The image sensor of  claim 1 , wherein a portion of the micro-lenses within the joint seam has a first radius of curvature, a different portion of the micro-lenses within the gap has a second radius of curvature, and the first radius of curvature is larger than the second radius of curvature. 
     
     
         7 . The image sensor of  claim 1 , wherein the micro-lenses within each of the groups of autofocus sensor units are spaced from each other, adjoining each other, or overlapping each other. 
     
     
         8 . The image sensor of  claim 1 , wherein a refractive index of the top film is lower than a refractive index of the micro-lenses.