Image sensor and method for manufacturing the same
View Patent ↗An image sensor and a method for manufacturing the same that includes photodiodes formed in a semiconductor substrate, a first insulating layer formed over the semiconductor substrate, the first insulating layer including a seed pattern corresponding spatially to the positions of the photodiodes, lower microlenses composed of an organic material formed over the seed pattern, a second insulating layer formed over the lower microlenses, a third insulating layer formed over the second insulating layer, color filters formed over the third insulating layer, and upper micro lenses formed over the color filters.
1. A method for manufacturing an image sensor comprising:
forming photodiodes in a semiconductor substrate;
forming a first insulating layer over the semiconductor substrate;
forming first insulating layer seed patterns corresponding spatially to the positions of the photodiodes by partially etching the first insulating layer;
forming lower micro lenses over the seed patterns, wherein the lower micro lenses having a hemispheric shape are formed by coating the first insulating layer including the seed patterns with an organic material comprising a thermosetting resin;
sequentially forming a second insulating layer and a third insulating layer over the lower microlenses;
forming color filters formed over the third insulating layer corresponding spatially to the lower microlenses; and
forming upper micro lenses over the color filters and corresponding spatially to the positions of the color filters.
2. The method of claim 1 , wherein forming the seed patterns comprises:
forming a photoresist pattern over regions of the uppermost surface of the first insulating layer corresponding spatially to the positions of the photodiodes; and then
partially etching the first insulating layer using the photoresist pattern as an etching mask.
3. The method of claim 2 , wherein the seed patterns are formed having one of a rectangular cross-section shape and a trapezoidal cross-section.
4. The method of claim 1 , wherein the first insulating layer including the seed patterns comprises undoped silicate glass (USG).
5. The method of claim 1 , wherein the second insulating layer and the third insulating layer comprise one of an oxide film and a nitride film.
6. A method for manufacturing an image sensor comprising:
forming isolation layers defining active regions and field regions in a semiconductor substrate;
forming photodiodes in the semiconductor substrate;
forming transistors electrically connected to the photodiodes over the semiconductor substrate;
forming a pre-metal dielectric layer over the entire semiconductor substrate including the photodiodes, the transistors and the isolation layers;
forming a first insulating layer over the pre-metal dielectric layer;
forming first insulating layer seed patterns corresponding spatially to the photodiodes;
forming lower microlenses by forming an organic layer over the seed patterns, wherein the organic layer comprises a thermosetting resin;
sequentially forming a second insulating layer and a third insulating layer over the lower microlenses;
forming color filters formed over the third insulating layer corresponding spatially to the lower microlenses; and
forming upper micro lenses over the color filters and corresponding spatially to the positions of the color filters.
7. The method of claim 6 , wherein the transistors comprise CMOS circuits.
8. The method of claim 6 , wherein the first insulating layer including the seed patterns comprises undoped silicate glass (USG).
9. The method of claim 6 , wherein the seed patterns are formed having one of a rectangular cross-section and a trapezoidal cross-section.