CMOS image sensor and fabricating method thereof
View Patent ↗A CMOS image sensor and fabricating method thereof can enhance the quality of the image sensor by preventing unnecessary diffused reflection of light by providing an opaque filter layer next to a microlens. The CMOS image sensor includes a photodiode, an insulating interlayer, a metal line, a device protecting layer, a microlens on the device protecting layer and overlapped with the photodiode, and an opaque layer pattern on the device protecting layer next to the microlens.
1. A CMOS image sensor comprising:
a photodiode in a semiconductor substrate;
an insulating interlayer on the semiconductor substrate including the photodiode;
a metal line embedded within the insulating interlayer;
a device protecting layer on the insulating interlayer;
a microlens on the device protecting layer, wherein the microlens overlaps the photodiode; and
an opaque layer pattern only on the device protecting layer between the microlens, wherein the opaque layer pattern overlaps the metal line.
2. The CMOS image sensor of claim 1 , wherein the metal line is embedded within the insulating interlayer and is not overlapped with the photodiode.
3. The CMOS image sensor of claim 2 , wherein the opaque layer pattern lies on the device protecting layer to be overlapped with the metal line.
4. The CMOS image sensor of claim 1 , wherein the device protecting layer comprises a nitride layer.
5. The CMOS image sensor of claim 1 , wherein the photodiode comprises red, green and blue photodiodes vertically stacked within the semiconductor substrate.
6. A method of fabricating a CMOS image sensor, comprising the steps of:
forming a photodiode in a semiconductor substrate;
forming a first insulating interlayer on the semiconductor substrate including the photodiode;
forming a metal line on the first insulating interlayer;
forming a second insulating interlayer on the first insulating interlayer including the metal line;
forming a device protecting layer on the second insulating interlayer;
forming a microlens on the device protecting layer to be overlapped with the photodiode; and
forming an opaque layer pattern only on the device protecting layer between the microlens, wherein the opague layer pattern overlaps the metal line.
7. The method of claim 6 , wherein the metal line is formed on the first insulating interlayer and is not overlapped with the photodiode.
8. The method of claim 7 , wherein the opaque layer pattern is formed on the device protecting layer and is overlapped with the metal line.
9. The method of claim 6 , wherein the device protecting layer is formed of a nitride layer.
10. The method of claim 6 , wherein the step of forming the photodiode comprises the steps of:
forming a first epitaxial layer in the semiconductor substrate;
forming a red photodiode on the first epitaxial layer;
forming a second epitaxial layer on the first epitaxial layer including the red photodiode;
forming a green photodiode on the second epitaxial layer;
forming a third epitaxial layer on the second epitaxial layer including the green photodiode; and
forming a blue photodiode on the third epitaxial layer.