IMAGE SENSOR WITH INLAID COLOR PIXELS IN ETCHED PANCHROMATIC ARRAY
An image sensor includes a substrate with a plurality of photosensitive elements. A transparent inorganic layer is situated over the substrate, and a plurality of openings is formed in the transparent inorganic layer. A color filter array has a plurality of panchromatic filter elements that are formed by the transparent inorganic layer, and a plurality of color filter elements are situated in the openings. The panchromatic filter elements and the color filter elements each include top surfaces that are essentially planar with the top surface of the transparent inorganic layer.
1 . An image sensor, comprising:
a substrate;
a pixel array of photosensitive elements disposed in the substrate;
one or more transparent inorganic layers disposed on the substrate;
a plurality of openings formed in the one or more transparent inorganic layers; and
a color filter array including a plurality of color filter elements situated in the openings, and a plurality of panchromatic filter elements formed by the one or more transparent inorganic layers situated between the openings.
2 . The image of claim 1 , wherein a top surface of the color filter elements and a top surface of the one or more transparent inorganic layers situated between the openings form a common plane.
3 . The image sensor of claim 1 , wherein the color filter elements include red, blue, and green filter elements.
4 . The image sensor of claim 1 , further comprising a microlens situated over the color filter array.
5 . The image sensor of claim 4 , further comprising a spacing layer situated between the color filter array and the microlens.
6 . The image sensor of claim 1 , wherein a high index material having a higher refractive index than the one or more transparent inorganic layers is disposed on at least the sidewalls of the openings.
7 . The image sensor of claim 6 , wherein the high index material comprises silicon nitride.
8 . The image sensor of claim 6 , wherein the high index material comprises a metal.
9 . A method of forming an image sensor, comprising:
forming an array of openings in one or more transparent inorganic layers disposed on a substrate;
depositing a plurality of color filter elements into the openings, wherein the remaining one or more transparent inorganic layers situated between the openings forms a plurality of panchromatic filter elements such that the color filter elements and the panchromatic filter elements form a color filter array having color filter elements and panchromatic filter elements.
10 . The method of claim 9 , wherein forming an array of openings comprises etching an array of openings in the one or more transparent inorganic layers.
11 . The method of claim 9 , further comprising depositing a layer of high index material over the transparent inorganic layer prior to depositing the plurality of color filter elements into the openings.
12 . The method of claim 9 , further comprising forming a microlens over the color filter array.
13 . The method of claim 12 , further comprising forming a spacing layer over the color filter array prior to forming the microlens over the color filter array.
14 . The method of claim 9 , further comprising forming a common plane by polishing the color filter array such that a top surface of the color filter elements and a top surface of the panchromatic filter elements are co-planar.
15 . The method of claim 11 , further comprising etching the layer of high index material such that high index material is disposed only on the sidewalls of the openings prior to depositing the plurality of color filter elements into the openings.
16 . An image capture device, comprising:
a pixel array of photosensitive elements disposed in the substrate;
one or more transparent inorganic layers disposed on the substrate;
a plurality of openings formed in the one or more transparent inorganic layers; and
a color filter array including a plurality of color filter elements situated in the openings, and a plurality of panchromatic filter elements formed by the one or more transparent inorganic layers situated between the openings.
17 . The image capture device of claim 16 , a top surface of the color filter elements and a top surface of the one or more transparent inorganic layers situated between the openings form a common plane.
18 . The image capture device of claim 16 , wherein the color filter elements include red, blue, and green filter elements.
19 . The image capture device of claim 16 , further comprising a microlens situated over the color filter array.
20 . The image capture device of claim 19 , further comprising a spacing layer situated between the color filter array and the microlens.
21 . The image capture device of claim 16 , wherein a high index material having a higher refractive index than the one or more transparent inorganic layers is disposed on at least the sidewalls of the openings.
22 . The image sensor of claim 21 , wherein the high index material comprises silicon nitride.
23 . The image sensor of claim 21 , wherein the high index material comprises a metal.