Metal mirror based multispectral filter array
A device may include a multispectral filter array disposed on the substrate. The multi spectral filter array may include a first metal mirror disposed on the substrate. The multi spectral filter may include a spacer disposed on the first metal mirror. The spacer may include a set of layers. The spacer may include a second metal mirror disposed on the spacer. The second metal mirror may be aligned with two or more sensor elements of a set of sensor elements.
1. A method comprising:
providing a substrate that includes a set of sensor elements;
depositing multiple layers of a multispectral filter array onto the substrate,
wherein the multiple layers include:
a first spacer layer disposed over all sensor elements in the set of sensor elements,
a second spacer layer disposed over less than all sensor elements in the set of sensor elements, and
a metal mirror,
depositing one or more other layers associated with the multispectral filter array onto the multiple layers; and
attaching a lens that alters a characteristic of light that is directed toward a corresponding sensor element of the sensor elements.
2. The method of claim 1 , wherein the multiple layers further include:
a first mirror structure that includes the metal mirror;
and
a second mirror structure that is deposited onto one or more portions of one or more of the first spacer layer or the second spacer layer.
3. The method of claim 2 , wherein the multiple layers further include:
an intermediate layer between the substrate and the first mirror structure.
4. The method of claim 1 ,
wherein the multiple layers include a mirror structure, and
wherein the mirror structure includes a partially transparent material that permits a first portion of light to be directed toward the set of sensor elements and a second portion of the light to be re-directed away from the set of sensor elements.
5. The method of claim 1 , wherein the metal mirror includes one of:
a silver (Ag)-based material,
an aluminum (Al)-based material, or
a copper (Cu)-based material.
6. The method of claim 1 , wherein depositing the multiple layers comprises:
using a pulsed magnetron sputtering deposition process to deposit one or more layers of the multiple layers onto the substrate or another layer of the multiple layers.
7. The method of claim 1 , wherein depositing the multiple layers comprises:
depositing a mirror structure that includes the metal mirror; and
utilizing a lift-off process to form a spacer layer on the mirror structure.
8. The method of claim 1 ,
wherein the first spacer layer includes one or more discrete portions that form a continuous spacer layer on the metal mirror.
9. The method of claim 8 , wherein the one or more discrete portions correspond to a plurality of channels aligned with the set of sensor elements.
10. The method of claim 1 , wherein the one or more other layers include one of:
an anti-reflective coating filter,
an out-of-band blocking filter, or
a higher-order suppression filter.
11. A method comprising:
depositing a first mirror structure onto a substrate associated with a set of optical sensors,
wherein the first mirror structure includes a metal mirror;
depositing a first spacer layer onto the first mirror structure,
wherein the first spacer layer covers the set of optical sensors;
depositing a second spacer layer that covers less than all of the set of optical sensors; and
depositing a second mirror structure onto one or more portions of one or more of the first spacer layer or the second spacer layer.
12. The method of claim 11 , wherein the second mirror structure is a different metal mirror disposed in alignment with one or more sensors of the set of optical sensors.
13. The method of claim 11 , wherein the set of optical sensors is a back illuminated sensor array.
14. The method of claim 11 , wherein one or more of the first spacer layer or the second spacer layer comprise a material selected to reduce an angle shift of light directed from a light source toward the set of optical sensors.
15. The method of claim 11 , wherein the set of optical sensors are disposed in a silicon-based wafer.
16. The method of claim 15 ,
wherein the substrate includes a glass-based substrate, and
wherein the silicon-based wafer is bonded to the glass-based substrate.
17. A method comprising:
providing a set of optical sensors;
depositing a mirror structure over the set of optical sensors,
wherein the mirror structure includes a metal mirror; and
depositing a plurality of spacer layers over the mirror structure,
wherein the plurality of spacer layers comprise:
a first spacer layer that covers the set of optical sensors, and
a second spacer layer that covers less than all sensors of the set of optical sensors.
18. The method of claim 17 , further comprising:
depositing a different mirror structure over one or more portions of the plurality of spacer layers.
19. The method of claim 18 , wherein the different mirror structure is a different metal mirror disposed in alignment with one or more sensors of the set of optical sensors.
20. The method of claim 17 , wherein the plurality of spacer layers further comprise:
a third spacer layer comprising:
a first portion that is deposited onto a portion of the first spacer layer, and
a second portion that is deposited onto a portion of the second spacer layer.