Image sensor and electronic apparatus including the image sensor
An image sensor is provided for obtaining an ultra-high resolution image. The image sensor includes a plurality of two-dimensionally arranged pixels, each of the plurality of pixels including a first meta-photodiode that selectively absorbs light of a red wavelength band, a second meta-photodiode that selectively absorbs light in a green wavelength band, and a third meta-photodiode that selectively absorbs light of a blue wavelength band. A width of each of the plurality of pixels of the image sensor may be less than a diffraction limit.
1. An image sensor comprising:
a plurality of pixels two-dimensionally arranged, each of the plurality of pixels comprising:
a first meta-photodiode configured to selectively absorb light of a red wavelength band;
a second meta-photodiode configured to selectively absorb light in a green wavelength band; and
a third meta-photodiode configured to selectively absorb light in a blue wavelength band,
wherein a width p of each of the plurality of pixels is less than or equal to a diffraction limit, wherein each of the first meta-photodiode, the second meta-photodiode and the third meta-photodiode has a columnar vertical structure.
2. 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 including a first conductivity-type semiconductor layer, an intrinsic semiconductor layer, and a second conductivity-type semiconductor layer stacked in a first direction,
wherein a cross-section of the first meta-photodiode perpendicular to the first direction has a first width, a cross-section of the second meta-photodiode perpendicular to the first direction has a second width, and a cross-section of the third meta-photodiode perpendicular to the first direction has a third width, and
wherein the first width, the second width and the third width are different from each other.
3. The image sensor of claim 2 , wherein a height of each of the first meta-photodiode, the second meta-photodiode, and the third meta-photodiode in the first direction is 500 nm or more.
4. The image sensor of claim 2 , wherein the first width, the second width, and the third width are in a range of about 50 nm to about 200 nm.
5. The image sensor of claim 2 , wherein the width p is in a range of 0.25 μm ≤p≤0.45 μm.
6. The image sensor of claim 2 , wherein the first width is larger than the second width and the second width is larger than the third width.
7. The image sensor of claim 2 , wherein a number of first meta-photodiodes included in a pixel is one, a number of second meta-photodiodes included in the pixel is one, and a number of third meta-photodiodes included in the pixel is two, wherein the first meta-photodiode, the second meta-photodiode, and the third meta-photodiode are provided so that a line connecting centers of the one first meta-photodiode, the one second meta-photodiodes, and the two third meta-photodiodes is a square.
8. The image sensor of claim 7 , wherein the two third meta-photodiodes are arranged in a diagonal direction of the square.
9. The image sensor of claim 2 , wherein a number of first meta-photodiodes included in a pixel is one, a number of second meta-photodiodes included in the pixel is more than one, and a number of third meta-photodiode included in the pixel is more than one, and wherein the first meta-photodiode is provided at the center of the pixel.
10. The image sensor of claim 9 , wherein the second meta-photodiode and the third meta-photodiode surround the first meta-photodiode in a square or regular hexagonal shape.
11. The image sensor of claim 2 , further comprising a fourth meta-photodiode that selectively absorbs light in an infrared wavelength band in each of the plurality of pixels.
12. The image sensor of claim 11 , wherein a width of a cross-section of the fourth meta-photodiode perpendicular to the first direction is greater than the first width, the second width, and the third width.
13. The image sensor of claim 12 , wherein a number of fourth meta-photodiodes included in a pixel is one, a number of first meta-photodiodes included in the pixel is more than one, a number of second meta-photodiodes included in the pixel is more than one, and a number of third meta-photodiode included in the pixel is more than one, and
wherein the fourth meta-photodiode is provided at the center of the one pixel.
14. The image sensor of claim 1 , further comprising a plurality of lenses facing the plurality of pixels in a one-to-one manner.
15. The image sensor of claim 1 , further comprising a circuit board supporting the first meta-photodiode, the second meta-photodiode, and the third meta-photodiode, the circuit board including circuit elements for processing signals from the plurality of pixels.
16. An image sensor comprising:
a plurality of pixels two-dimensionally arranged, each of the plurality of pixels including:
two or more meta-photodiodes that selectively absorb light of two or more different wavelength bands, and
a width of each of the plurality of pixels is less than or equal to a shortest wavelength among different wavelength bands.
17. The image sensor of claim 16 , wherein each of the two or more meta-photodiodes has a rod shape including a first conductivity-type semiconductor layer, an intrinsic semiconductor layer, and a second conductivity-type semiconductor layer stacked in a first direction,
wherein the two or more meta-photodiodes include a first meta-photodiode, a second meta-photodiode, and a third meta-photodiode,
wherein a cross-section of the first meta-photodiode perpendicular to the first direction has a first width, a cross-section of the second meta-photodiode perpendicular to the first direction has a second width, and a cross-section of the third meta-photodiode perpendicular to the first direction has a third width, and
wherein the first width, the second width and the third width are different from each other.
18. The image sensor of claim 17 , wherein, among the two or more meta-photodiodes, a first meta-photodiode absorbs light of a first wavelength, and a second meta-photodiode absorbs light of a second wavelength,
wherein the first wavelength is longer than the second wavelength, and
wherein the first meta-photodiode has a greater width than the second meta-photodiode.
19. An electronic apparatus comprising:
a lens assembly including one or more lenses, the 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 the electrical signal generated by the image sensor, wherein
the image sensor includes a plurality of pixels two-dimensionally arranged, each of the plurality of pixels including a first meta-photodiode configured to selectively absorb light of a red wavelength band, a second meta-photodiode configured to selectively absorb light of a green wavelength band and a third meta-photodiode configured to selectively absorb light of a blue wavelength band, and
wherein a width p of each of the plurality of pixels satisfies the following:
p<λ·F,
where, F is an F-number of the lens assembly, and λ is a center wavelength of a blue wavelength band.
20. The electronic apparatus of claim 19 , wherein each of the plurality of pixels of the image sensor further comprises a fourth meta-photodiode that selectively absorbs light of an infrared wavelength band, and the processor calculates color information and depth information of the object.