Image sensor having lens type color filter and method for fabricating the same
View Patent ↗The image sensor includes lens-type color filters having a uniform shape for a plurality of pixels. The image sensor includes a plurality of pixels formed in a substrate, a plurality of color filter housings formed over outer boundaries of the respective pixels, and a plurality of color filters filled in spaces defined by the respective color filter housings, wherein the clock filter housings surround edges of the respective color filters with a given curvature.
1. A method for forming an image sensor, the method comprising:
forming sacrificial patterns over a substrate including a plurality of pixels, corresponding to the respective pixels;
performing a reflow process on the sacrificial patterns to have a round edge;
forming a mold layer along a surface of a structure including the sacrificial patterns;
patterning the mold layer using mask patterns as an etching mask to form a plurality of color filter housings surrounding edges of the respective sacrificial patterns with a given curvature;
removing the mask patterns and the sacrificial patterns to form spaces defined by the color filter housings; and
filling the spaces with color filter materials to form a plurality of color filters over the respective pixels.
2. The method of claim 1 , further comprising:
forming a protection layer over a structure including the color filters and the color filter housings.
3. The method of claim 1 , wherein the sacrificial patterns cover the respective pixels and exposes outer boundaries of the respective pixels.
4. The method of claim 1 , wherein the mold layer includes material whose refractive index is larger than that of air and smaller than that of the color filters.
5. The method of claim 1 , wherein the mask patterns cover the respective pixels while having openings exposing centers of the respective pixels.
6. The method of claim 1 , wherein the mask patterns and the sacrificial patterns include the same material.
7. The method of claim 2 , wherein the protection layer has a refractive index larger than that of air and smaller than those of the color filters and the color filter housings.
8. The method of claim 2 , further comprising:
forming microlens over the protection, corresponding to the respective pixels.