ULTRAVIOLET LIGHT FILTER LAYER IN IMAGE SENSORS
An image sensor includes one or more ultraviolet (UV) light filter layers disposed between an insulating layer and a color filter array (CFA) layer. The one or more UV light filter layers reflect or absorb UV light while transmitting visible light.
1 . An image sensor, comprising:
at least one ultraviolet light filter layer disposed between a color filter array and an insulating layer, wherein the at least one ultraviolet light filter layer blocks UV light while transmitting visible light.
2 . The image sensor of claim 1 , wherein the ultraviolet light filter layer comprises a layer of silicon.
3 . The image sensor of claim 1 , wherein the ultraviolet light filter layer comprises a UV absorbing material.
4 . The image sensor of claim 3 , wherein the UV absorbing material is included in another material.
5 . The image sensor of claim 3 , wherein the UV absorbing material comprises an evaporated pigment.
6 . The image sensor of claim 3 , wherein the UV absorbing material comprises a dye.
7 . The image sensor of claim 6 , wherein the dye comprises one of an organic pigment and an inorganic pigment.
8 . The image sensor of claim 1 , wherein the image sensor comprises one of a front-illuminated image sensor and a back-illuminated image sensor.
9 . A back-illuminated image sensor, comprising:
a sensor layer disposed between an insulating layer and a circuit layer electrically connected to the sensor layer, wherein a frontside of the sensor layer is adjacent to the circuit layer and a backside of the sensor layer is adjacent to the insulating layer;
one or more ultraviolet light filter layers overlying the insulating layer, wherein the at least one ultraviolet light filter layer blocks UV light while transmitting visible light; and
a color filter array formed over the one or more ultraviolet light filter layers.
10 . The back-illuminated image sensor of claim 9 , wherein the ultraviolet light filter layer comprises a layer of silicon.
11 . The back-illuminated image sensor of claim 9 , wherein the ultraviolet light filter layer comprises a UV absorbing material.
12 . The image sensor of claim 11 , wherein the UV absorbing material is included in another material.
13 . The image sensor of claim 11 , wherein the UV absorbing material comprises an evaporated pigment.
14 . The back-illuminated image sensor of claim 11 , wherein the UV absorbing material comprises a dye.
15 . The back-illuminated image sensor of claim 14 , wherein the dye comprises one of an organic pigment and an inorganic pigment.
16 . A method for fabricating an image sensor having an imaging area that includes a plurality of pixels, the method comprising:
forming an insulating layer over the imaging area;
forming one or more ultraviolet light filter layers over the insulating layer, wherein the at least one ultraviolet light filter layer blocks UV light while transmitting visible light; and
forming a color filter array over the one or more ultraviolet light filter layers.
17 . The method of claim 16 , wherein forming one or more ultraviolet light filter layers over the insulating layer comprises forming a layer of silicon over the insulating layer.
18 . The method of claim 16 , wherein forming one or more ultraviolet light filter layers over the insulating layer comprises forming a UV absorbing material over the insulating layer.
19 . The method of claim 18 , wherein the UV absorbing material comprises a dye.
20 . The method of claim 19 , wherein the dye comprises one of an organic pigment and an inorganic pigment.