Device for detecting an electromagnetic radiation
The electromagnetic radiation detection device includes, on a same substrate: at least one active detector of the electromagnetic radiation provided with a first element sensitive to said radiation, at least one reference detector including a second element sensitive to said electromagnetic radiation, and a lid provided with first reflective means reflecting the incident electromagnetic radiation, said lid covering without contact the second sensitive element and defining with the substrate a cavity having the reference detector housed therein. The lid is designed to improve the sensitivity of the detection device.
1. An electromagnetic radiation detection device comprising, on a same substrate:
an active detector of the electromagnetic radiation provided with a first element sensitive to said electromagnetic radiation,
a reference detector comprising a second element sensitive to said electromagnetic radiation, said second sensitive element having a first main surface facing an incident electromagnetic radiation and an opposite second main surface facing the substrate,
a reflector comprising reflecting sidewalls supporting a reflecting cover, said reflecting cover and said reflecting sidewalls being configured for reflecting the incident electromagnetic radiation, and covering without contact the reference detector wherein said active detector is outside of the reflector, wherein the reflecting cover and the second sensitive element are separated by an empty space and by a distance ranging between 0.5μm and 5μm.
2. The device according to claim 1 , wherein said distance is greater than or equal to 0.5μm and strictly smaller than 2μm.
3. The device according to claim 1 , wherein said reflector comprises a support wall transparent to the electromagnetic radiation disposed on the substrate and arranged between said reflecting cover, said reflecting sidewalls and the substrate.
4. The device according to claim 3 , wherein said support wall is formed by a material selected from among single-crystal silicon, polycrystalline silicon, or amorphous silicon, single-crystal germanium, polycrystalline germanium, or amorphous germanium, silicon-germanium alloys, zinc sulfide, zinc selenide, silicon oxides, and silicon oxynitrides.
5. The device according to claim 1 , wherein said reflector comprises an external wall formed by a support wall transparent to the electromagnetic radiation and wherein said reflecting cover and said reflecting sidewalls are arranged between said support wall and the substrate, and are directly disposed on the substrate.
6. The device according to claim 5 , wherein said support wall is formed by a material selected from among single-crystal silicon, polycrystalline silicon, or amorphous silicon, single-crystal germanium, polycrystalline germanium, or amorphous germanium, silicon-germanium alloys, zinc sulfide, zinc selenide, silicon oxides, and silicon oxynitrides.
7. The device according to claim 1 , wherein said reflector comprises a structural layer arranged between said reflecting cover and the substrate.
8. The device according to claim 1 , wherein said reflector is disposed on the substrate via two lateral sides and covers the reference detector by forming a bridge above said detector, and wherein each lateral side has a continuous internal surface and a continuous external surface and wherein the reflective sidewalls form at least the continuous internal surfaces or the continuous external surfaces of the lateral sides.
9. The device according to claim 1 , wherein said reflector totally encapsulates the reference detector.
10. The device according to claim 1 , wherein said reflecting cover and said reflecting sidewalls are formed by a metal layer of at least one metal material selected from among aluminum, titanium, gold, nickel, tantalum, tungsten, molybdenum, nitrides and silicides thereof, and their alloys.
11. The device according to claim 1 , comprising a plurality of reference detectors and at least two reflectors each independently covering one of the reference detectors.
12. The device according to claim 1 , comprising a plurality of reference detectors and wherein said reflector covers the plurality of reference detectors and no active detector.
13. The device according to claim 12 , wherein the reflector is devoid of internal separation wall separating two consecutive reference detectors.
14. The device according to claim 12 , wherein said reflector has at least one internal separation wall arranged between two adjacent reference detectors so that the reflector defines with the substrate several empty spaces, each of them having a reference detector housed therein.
15. The device according to claim 12 , comprising several active detectors of the electromagnetic radiation and as many reference detectors as active detectors.
16. The device according to claim 12 , comprising at least three active detectors, wherein the number of reference detectors is smaller than the number of active detectors, and wherein the active detectors and the reference detectors are arranged on the substrate in the form of an array of rows and of columns, each reference detector being placed on the substrate at the head end of a row and/or of a column of the array.
17. The device according to claim 16 , wherein said reflector only covers the reference detectors arranged on a same line or a same column of the array.
18. The device according to claim 1 , wherein said reference detector is identical to the active detector of the electromagnetic radiation.
19. The device according to claim 1 , wherein the reflecting sidewalls comprise a material that reflects infrared radiation.