Image sensor and method for manufacturing the same
View Patent ↗Disclosed are an image sensor and a method for manufacturing the same. The image sensor includes a semiconductor substrate including a unit pixel, first to third color filters provided on the semiconductor substrate, a first micro-lens provided on each of the first and third color filters, and a second micro-lens provided on the second color filter, in which an outer periphery of the first micro-lens has a square shape, and an upper portion of the first micro-lens has a semi-spherical or convex shape.
1. An image sensor comprising:
a semiconductor substrate including a plurality of unit pixels;
an interlayer dielectric layer and a metal interconnection on the semiconductor substrate, wherein the interlayer dielectric layer comprises a plurality of dielectric layers, each dielectric layer comprising a lowermost etch stop layer, at least one conformal or gap-fill dielectric layer, at least one bulk dielectric layer, and at least one cap layer;
first, second and third color filters on or over the semiconductor substrate, the first color filter having a first color, the second color filter having a second color different from the first, and the third color filter having a third color different from the first and the second colors;
first micro-lenses in physical contact with the first and third color filters, each of the first micro-lenses comprising (i) a lower portion having a square shape and an outer periphery with substantially vertical sidewalls and (ii) an upper portion having a convex shape; and
second micro-lenses on the second color filters.
2. The image sensor of claim 1 , wherein the outer periphery of each of the second micro-lenses has a circular shape.
3. The image sensor of claim 1 , wherein the first color filter includes a red color filter, the second color filter includes a green color filter, and the third color filter includes a blue color filter.
4. The image sensor of claim 1 , wherein the second color filter is at opposite sides of the first color filter and the third color filter.
5. The image sensor of claim 4 , comprising twice as many second color filters as first color filters or third color filters.
6. The image sensor of claim 1 , wherein the lower portion of each of the first micro-lenses has a height of 100 to 8000 nm.
7. The image sensor of claim 6 , wherein the lower portion of each of the first micro-lenses has a height of 500 to 5000 nm.
8. The image sensor of claim 1 , wherein, in a top view, the outer periphery of the lower portion of each of the first micro-lenses has substantially straight segments.
9. The image sensor of claim 8 , wherein the substantially straight segments constitute at least half of the entire outer periphery.
10. The image sensor of claim 1 , wherein the second color filter is at opposite sides of the first color filter.
11. The image sensor of claim 1 , wherein the second color filter is at opposite sides of the third color filter.
12. The image sensor of claim 1 , wherein each of the first micro-lenses has a same radius of curvature along its width, length, and diagonal directions.
13. The image sensor of claim 1 , wherein the unit pixel comprises a photodiode and a CMOS circuit.
14. The image sensor of claim 13 , wherein the CMOS circuit comprises a reset transistor, a select transistor, a drive transistor, and an optional transfer transistor.
15. The image sensor of claim 1 , wherein the metal interconnection comprises at least one lowermost adhesive or diffusion barrier layer, at least one bulk conductive layer, and at least one uppermost adhesive, hillock prevention and/or antireflective coating layer.
16. The image sensor of claim 1 , further comprising a lowermost metal interconnection electrically connected to a source/drain terminal.
17. The image sensor of claim 1 , wherein each of the second micro-lenses comprises (i) a lower portion having a square shape and an outer periphery with substantially vertical sidewalls and (ii) an upper portion having a convex shape.