Infra-red device
We disclose herein an infra-red (IR) device comprising a substrate comprising an etched cavity portion and a substrate portion; a dielectric layer disposed on the substrate. The dielectric layer comprises a dielectric membrane which is adjacent, or directly above, or below the etched cavity portion of the substrate. The device further comprises a reflective layer on or in or above or below the dielectric membrane to enhance emission or absorption of infrared light at one or more wavelengths.
1. An infra-red (IR) device comprising:
a substrate comprising an etched cavity portion and a substrate portion;
a dielectric layer disposed on the substrate, wherein the dielectric layer comprises a dielectric membrane, wherein the dielectric membrane is adjacent to the etched cavity portion of the substrate;
a reflective layer on or in the dielectric membrane to enhance emission or absorption of an entire spectrum of infrared light wavelengths, and wherein the reflective layer consists of a single continuous layer, and wherein the reflective layer extends through an entire area of the dielectric membrane.
2. A device according to claim 1 , wherein the reflective layer is located directly underneath the dielectric membrane.
3. A device according to claim 1 , wherein the reflective layer is located directly above the dielectric membrane.
4. A device according to claim 1 , wherein the reflective layer is located on walls of the etched cavity portion.
5. A device according to claim 1 , wherein the reflective layer comprises a material selected from gold, platinum, aluminum, copper, chromium, nickel, titanium, tungsten and a combination of any of these materials.
6. A device according to claim 1 , comprising further reflective structures outside the dielectric membrane between the dielectric layer and solder balls to act as interconnections or pads.
7. A device according to claim 1 , further comprising an optically transmissive layer attached to the substrate.
8. A device according to claim 1 , further comprising any one of a filter, window, or lens built at a wafer level.
9. A device according to claim 1 , further comprising through-semiconductor vias placed within the substrate to connect the IR device to other circuits.
10. A device according to claim 9 , further comprising at least one bonding ball coupled with the through-semiconductor via.
11. A device according to claim 1 , wherein the device is an infrared emitter having a micro-heater embedded below, above or within the membrane.
12. A device according to claim 1 , wherein the device is an infrared detector, and wherein the detector comprises any one of a thermopile, a pyro detector, a thermal diode or a bolometer.
13. A device according to claim 1 , wherein the device has a flip-chip configuration.
14. A device according to claim 1 , wherein the device is configured to be placed above an application specific integrated circuit using a flip chip technique.
15. A device according to claim 1 , wherein the device is configured such that a lattice or chemical structure of the reflective layer is changed during operation.
16. An IR device array assembly comprising:
an array of a plurality of IR devices according to claim 1 , wherein said plurality of devices are formed on a single chip.
17. A method of manufacturing an infrared device according to claim 1 , the method comprising:
fabricating wafers and devices containing IR devices; and
forming a reflective layer either prior to or after etching of the substrate.