Image sensor and method of fabricating the same
View Patent ↗Provided is an image sensor including an overcoating layer and at least two micro lenses formed on the overcoating layer. The image sensor is characterized in that the overcoating layer positioned below a clearance between the micro lenses is etched such that curved surfaces of the micro lenses extend to the etched overcoating layer, and a contamination in the bonding pad can be prevented.
1. A method of fabricating an image sensor, comprising:
forming an element layer on a substrate which is divided into a pixel array area and a bonding pad area;
forming a bonding pad on the bonding pad area of the element layer;
forming a passivation layer covering the bonding pad on the element layer;
selectively etching the passivation layer on the bonding pad to form a partially remaining passivation layer such that the bonding pad is not exposed;
forming a color filter layer on the pixel array area of the passivation layer;
forming an overcoating layer on the color filter layer;
forming at least two micro lenses on the overcoating layer; and
etching the partially remaining passivation layer exposing the bonding pad.
2. The method of claim 1 , wherein the micro lenses are formed at an interval range of 0.5-1.0 μm.
3. The method of claim 1 , wherein the etching of the partially remaining passivation layer comprises etching the overcoating layer disposed below the clearance between the micro lenses and the partially remaining passivation layer at the same time such that curved surfaces of the micro lenses extend.
4. The method of claim 3 , after the overcoating layer disposed below the clearance is etched, further comprising flowing the micro lenses such that the curved surfaces of the micro lenses extend to the overcoating layer.
5. The method of claim 1 , after the forming of the micro lenses, further comprising etching the overcoating layer disposed below a clearance between the micro lenses such that curved surfaces of the micro lenses extend.
6. The method of claim 1 , wherein the partially remaining passivation layer is 500-2,000 Å thick.
7. The method of claim 1 , further comprising forming a non-fluid film, which fills a clearance between the micro lenses and has a greater refractivity than the micro lenses, on the micro lenses after the micro lenses have been formed.
8. The method of claim 7 , wherein the non-fluid film is an inorganic insulator film.
9. The method of claim 8 , wherein the inorganic insulator film is a material selected from the group consisting of inorganic oxide film, inorganic oxide nitride film and inorganic nitride film.
10. The method of claim 7 , wherein the non-fluid film is formed after the partially remaining passivation layer is etched.