Image sensor and electronic apparatus including the image sensor
An image sensor may include a pixel array including a plurality of two-dimensionally arranged pixels. Each pixel may include a first meta-photodiode absorbing light of a first wavelength band; a second meta-photodiode absorbing light in a second wavelength band; and a third meta-photodiode absorbing light of a third wavelength band, wherein the first meta-photodiode, the second meta-photodiode, and the third meta-photodiode may be arranged in an area having a size less than a diffraction limit. The arrangement form of the first meta-photodiode, the second meta-photodiode, and the third meta-photodiode arranged in the plurality of pixels in a central portion of the pixel array may be the same as the arrangement form of the first meta-photodiode, the second meta-photodiode, and the third meta-photodiode arranged in the plurality of pixels in a periphery of the pixel array.
1 . An image sensor comprising:
a pixel array comprising a plurality of two-dimensionally arranged pixels,
wherein each of the plurality of pixels comprises:
a first meta-photodiode configured to selectively absorb light of a first wavelength band;
a second meta-photodiode configured to selectively absorb light of a second wavelength band different from the first wavelength band; and
a third meta-photodiode configured to selectively absorb light of a third wavelength band different from the first wavelength band and second wavelength band,
wherein, the first meta-photodiode, the second meta-photodiode, and the third meta-photodiode are arranged in an area having dimensions equal to or less than 450 nm×450 nm,
wherein the first meta-photodiode, the second meta-photodiode, and the third meta-photodiode of one or more first pixels in a central portion of the pixel array, among the plurality of pixels, are arranged in a same form as the first meta-photodiode, the second meta-photodiode, and the third meta-photodiode of one or more second pixels in a periphery of the pixel array, among the plurality of pixels,
wherein each of the plurality of pixels comprises one of the first meta-photodiode, one of the second meta-photodiode, and two of the third meta-photodiode, and
wherein the first meta-photodiode and the second meta-photodiode are provided in a first diagonal direction, and the two third meta-photodiodes are provided in a second diagonal direction crossing the first diagonal direction.
2 . The image sensor of claim 1 , wherein, in the central portion and the periphery of the pixel array, the first meta-photodiodes arranged in the plurality of pixels have a same first structure, the second meta-photodiodes have a same second structure, and the third meta-photodiodes have a same third structure.
3 . The image sensor of claim 1 , wherein, in each of the plurality of pixels, the following condition is satisfied: W/2+40 nm>S, where S is a spacing between two meta-photodiodes adjacent in a first direction among the first meta-photodiode, the second meta-photodiode, and the third meta-photodiode and W is a sum of widths of the two adjacent meta-photodiodes.
4 . The image sensor of claim 1 , wherein, in each of the plurality of pixels, a spacing between two meta-photodiodes adjacent in a first direction among the first meta-photodiode, the second meta-photodiode, and the third meta-photodiode is about 150 nm or less, and is at least ½ of a sum of widths of the two adjacent meta-photodiodes.
5 . The image sensor of claim 1 , wherein, in each of the plurality of pixels, a spacing between two meta-photodiodes adjacent in a first direction among the first meta-photodiode, the second meta-photodiode, and the third meta-photodiode is one third or less of 450 nm×450 nm.
6 . The image sensor of claim 1 , wherein the central portion of the pixel array is a first area in which incident light is vertically incident, and the periphery of the pixel array surrounds the central portion and is a second area in which incident light is obliquely incident.
7 . The image sensor of claim 1 , wherein the pixel array further comprises:
an optical plate arranged to face light incident surfaces of the plurality of pixels and configured to change a traveling direction of incident light to be perpendicular to the light incident surfaces of the plurality of pixels.
8 . The image sensor of claim 7 , wherein the optical plate comprises a digital micro-lens array or a digital deflector.
9 . The image sensor of claim 1 , wherein each of the first meta-photodiode, the second meta-photodiode, and the third meta-photodiode has a rod-shape comprising:
a first conductivity-type semiconductor layer,
an intrinsic semiconductor layer stacked on the first conductivity-type semiconductor layer, and
a second conductivity-type semiconductor layer stacked on the intrinsic semiconductor layer, and
wherein the first meta-photodiode, the second meta-photodiode, and the third meta-photodiode respectively have a first width, a second width, and a third width different from each other in a direction perpendicular to a stacking direction.
10 . The image sensor of claim 9 , wherein the first width, the second width, and the third width are about 50 nm to about 200 nm.
11 . The image sensor of claim 9 , wherein the first wavelength band is greater than the second wavelength band, and the second wavelength band is greater than the third wavelength band, and
wherein the first width is greater than the second width, and the second width is greater than the third width.
12 . The image sensor of claim 9 , wherein heights of the first meta-photodiode, the second meta-photodiode, and the third meta-photodiode in the stacking direction are about 500 nm or more.
13 . The image sensor of claim 12 , wherein the heights of the first meta-photodiode, the second meta-photodiode, and the third meta-photodiode in the stacking direction are same as each other.
14 . The image sensor of claim 1 , wherein each of the plurality of pixels has a width of about 250 nm to about 450 nm.
15 . The image sensor of claim 1 , wherein a sum of the number of the first meta-photodiodes, the second meta-photodiodes, and the third meta-photodiodes arranged in each of the plurality of pixels is nine, and the nine meta-photodiodes are arranged in the form of a 3×3 array.
16 . The image sensor of claim 1 , wherein each of the plurality of pixels comprises one of the first meta-photodiodes, a plurality of the second meta-photodiodes, and a plurality of the third meta-photodiodes, and
wherein the first meta-photodiode is located at the center of each of the plurality of pixels.
17 . An image sensor comprising:
a pixel array comprising a plurality of two-dimensionally arranged pixels,
wherein each of the plurality of pixels comprises:
a first meta-photodiode configured to selectively absorb light of a first wavelength band;
a second meta-photodiode configured to selectively absorb light in a second wavelength band different from the first wavelength band; and
a third meta-photodiode configured to selectively absorb light of a third wavelength band different from the first wavelength band and second wavelength band,
wherein the first meta-photodiode, the second meta-photodiode, and the third meta-photodiode are arranged in an area having dimensions less than 450 nm×450 nm, and
wherein a spacing between two meta-photodiodes adjacent in a first direction among the first meta-photodiode, the second meta-photodiode, and the third meta-photodiode is about 150 nm or less, and the spacing is at least ½ of a sum of widths of the two adjacent meta-photodiodes,
wherein each of the plurality of pixels comprises one of the first meta-photodiode, one of the second meta-photodiode, and two of the third meta-photodiode, and
wherein the first meta-photodiode and the second meta-photodiode are provided in a first diagonal direction, and the two third meta-photodiodes are provided in a second diagonal direction crossing the first diagonal direction.
18 . The image sensor of claim 17 , wherein, in an entire area of the pixel array, the first meta-photodiode, the second meta-photodiode, and the third meta-photodiode arranged in each of the plurality of pixels have a same arrangement form.
19 . An electronic apparatus comprising:
a lens assembly configured to form an optical image of an object;
an image sensor configured to convert the optical image formed by the lens assembly into an electrical signal; and
a processor configured to process a signal generated by the image sensor, wherein the image sensor comprises a pixel array including a plurality of two-dimensionally arranged pixels, and
each of the plurality of pixels comprises:
a first meta-photodiode configured to selectively absorb light of a first wavelength band;
a second meta-photodiode configured to selectively absorb light of a second wavelength band different from the first wavelength band; and
a third meta-photodiode configured to selectively absorb light of a third wavelength band different from the first wavelength band and second wavelength band,
wherein, the first meta-photodiode, the second meta-photodiode, and the third meta-photodiode are arranged in an area having dimensions less than 450 nm×450 nm, and
wherein the first meta-photodiode, the second meta-photodiode, and the third meta-photodiode of one or more first pixels in a central portion of the pixel array, among the plurality of pixels, are arranged in a same form as the first meta-photodiode, the second meta-photodiode, and the third meta-photodiode of one or more of second pixels in a periphery of the pixel array, among the plurality of pixels,
wherein each of the plurality of pixels comprises one of the first meta-photodiode, one of the second meta-photodiode, and two of the third meta-photodiode, and
wherein the first meta-photodiode and the second meta-photodiode are provided in a first diagonal direction, and the two third meta-photodiodes are provided in a second diagonal direction crossing the first diagonal direction.