CMOS image sensor
View Patent ↗Provided are a CMOS image sensor in which microlenses are formed in a remaining space in a patterned light shielding layer to improve image sensor characteristics and to protect the microlenses during packaging. The CMOS image sensor may include: a semiconductor substrate; at least one photodiode on or in the semiconductor substrate; a first insulating layer on the substrate including the photodiode(s); a plurality of metal lines on and/or in the first insulating layer; a second insulating layer on the first insulating layer including at least some of the metal lines; a patterned light shielding layer on the second insulating layer; and microlenses in a remaining space on the second insulating layer.
1. A CMOS image sensor comprising:
a semiconductor substrate;
a plurality of photodiodes on or in the semiconductor substrate;
a first insulating layer on the substrate including the photodiodes;
a plurality of metal lines on or in the first insulating layer;
a second insulating layer on the first insulating layer and at least some of the metal lines;
a patterned light shielding layer on the second insulating layer; and
microlenses in a remaining space on the second insulating layer not occupied by the patterned light shielding layer.
2. The CMOS image sensor according to claim 1 , wherein the light shielding layer pattern corresponds to the metal lines.
3. The CMOS image sensor according to claim 1 , wherein the patterned light shielding layer and the microlenses do not overlap each other.
4. The CMOS image sensor according to claim 1 , wherein the light shielding layer has a thickness at least equal to that of the microlenses.
5. The CMOS image sensor according to claim 4 , wherein the light shielding layer has a thickness greater than that of the microlenses.
6. The CMOS image sensor according to claim 1 , wherein the second insulating layer comprises a planarized oxide and/or nitride layer.
7. The CMOS image sensor according to claim 6 , wherein the second insulating layer comprises a planarized oxide layer.
8. The CMOS image sensor according to claim 6 , wherein the second insulating layer comprises a planarized nitride layer.
9. The CMOS image sensor according to claim 1 , wherein the microlenses are self-aligned to ensure space for the microlenses.
10. The CMOS image sensor according to claim 1 , wherein the patterned light shielding layer comprises a plurality of light shielding structures.
11. The CMOS image sensor according to claim 10 , wherein the microlenses are between adjacent light shielding structures.
12. The CMOS image sensor according to claim 11 , wherein the microlenses extend an entire length between adjacent light shielding structures.
13. The CMOS image sensor according to claim 1 , wherein the microlenses occupy an entire remaining space on the second insulating layer.
14. The CMOS image sensor according to claim 1 , wherein the second insulating layer has a planarized upper surface.
15. The CMOS image sensor according to claim 14 , wherein lower surfaces of the light shielding layer and microlenses are co-planar with the upper surface of the second insulating layer.
16. The CMOS image sensor according to claim 1 , wherein the light shielding layer comprises at least one of carbon, graphite, or CrO 3 .
17. The CMOS image sensor according to claim 1 , wherein the light shielding layer has a thickness substantially equal to that of the microlenses.