Sensor structure for optical performance enhancement
View Patent ↗The present disclosure provides an image sensor semiconductor device. The image sensor semiconductor device includes an image sensor disposed in a semiconductor substrate, an inter-level dielectric (ILD) layer disposed on the semiconductor substrate, inter-metal-dielectric (IMD) layers and multi-layer interconnects (MLI) formed on the ILD layer, and a color filter formed in at least one of the IMD layers and overlying the image sensor.
1. An image sensor semiconductor device, comprising:
an image sensor disposed in a semiconductor substrate;
an inter-level dielectric (ILD) layer disposed on the semiconductor substrate;
a plurality of inter-metal-dielectric (IMD) layers and multi-layer interconnects (MLI) formed on the ILD layer; and
a color filter formed in at least one of the IMD layers and the ILD layer and overlying the image sensor.
2. The device of claim 1 , wherein the color filter comprises a dielectric material transparent to only one of red visible light, green visible light, and blue visible light.
3. The device of claim 1 , wherein the color filter extends into the ILD.
4. The device of claim 1 , wherein the color filter feature comprises a height ranging between about 300 nanometer and about 5000 nanometer.
5. The device of claim 1 , wherein the color filter comprises a sectional area ranging between about 0.36 micron 2 and about 17.64 micron 2 .
6. The device of claim 1 , wherein the color filter comprises one of a circular shape in sectional view and a rectangular shape in sectional view.
7. The device of claim 1 , wherein the color filter comprises a tapered profile with a greater sectional area at a top surface of the color filter.
8. The device of claim 1 , wherein the color filter comprises a multi-step profile with a decreased dimension from top to bottom.
9. The device of claim 1 , wherein the image sensor comprises one of a photodiode and a pinned photodiode.
10. The device of claim 1 , wherein the MLI further comprises a topmost metal feature disposed horizontally within a peripheral region and vertically above the color filter, the topmost metal feature extending vertically within a first dimension; and
a micro lens overlying the color filter and vertically extending at least partially within the first dimension.
11. The device of claim 10 , wherein the topmost interconnect feature comprises at least one of a bonding pad and a probe test pad.
12. The device of claim 1 , wherein the color filter is further enclosed with a lining material layer.
13. The device of claim 12 , wherein the lining material layer comprises silicon nitride.
14. A method of fabricating a semiconductor device, comprising:
forming an image sensor in a semiconductor substrate;
forming an interlayer dielectric (ILD) layer on the semiconductor substrate;
forming a plurality of inter-metal-dielectric (IMD) layers and multilayer interconnects (MLI) on the ILD layer;
forming a hole that extends vertically within at least one of the IMD layers and the ILD layer and overlying the image sensor; and
filling the hole with a color filter material to form a color filter.
15. The method of claim 14 , further comprising:
forming a topmost metal feature horizontally within a peripheral region and vertically above the MLI and the color filter, the topmost metal feature vertically extending within a first dimension; and
forming a micro lens overlying the color filter and vertically extending at least partially within the first dimension.
16. The method of claim 14 , further comprising lining the hole with a dielectric material layer before the filling.
17. The method of claim 14 , wherein the forming of the hole comprises one of:
forming the hole with a tapered profile by implementing a tunable etching process; and
forming the hole with a tapered profile by implementing a dry etching process and then a wet etching process.
18. An image sensor device, comprising:
an image sensor element disposed in a silicon substrate;
an inter-level dielectric (ILD) layer disposed on the semiconductor substrate;
a plurality of inter-metal-dielectric (IMD) layers and multilayer interconnects (MLI) formed on the ILD layer; and
a color filter disposed in a structure that extends vertically within the IMD layers and the ILD layer, the color filter being vertically aligned with an image-sensing region of the image sensor.
19. The image sensor device of claim 18 , further comprising a topmost metal feature above the MLI and the color filter.
20. The image sensor device of claim 18 , further comprising a dielectric material layer lined in the structure.