Multispectral imaging device
A multispectral imaging device comprises a hybrid semiconductor device of stacked type to separate different light wavebands in a three-dimensional space, said hybrid semiconductor device comprises: a first photodiode, to convert NIR light photons to electrons, said first photodiode forming a detecting array of infrared light image, said first photodiodes comprising a substrate and an depletion layer; and a second photodiode, arranged on said first photodiode, to convert visible light photons to electrons, said second photodiode forming a detecting array of visible light image. The multispectral imaging device provided by the present disclosure decreases the cross-talk between different photodiodes and increases the total performance.
1. A multispectral imaging device, comprising a hybrid semiconductor device of stacked type to separate different wavebands in a three-dimensional space, said hybrid semiconductor device comprising:
a first photodiode, configured to convert NIR light photons to electrons, wherein a first plurality of said first photodiode forms a detecting array of infrared light image, said first photodiode comprising a substrate and a depletion layer formed in said substrate, wherein said first photodiode is made of crystal silicon material; and
a second photodiode, arranged on said first photodiode, configured to convert visible light photons to electrons, wherein a second plurality of said second photodiode of forms a detecting array of visible light image, said second photodiode is NIP or PIN type, and said second photodiode is made of hydrogenated amorphous silicon material;
said multispectral imaging device comprising a plurality of sub-pixels comprising a plurality of first kind of sub-pixels and a plurality of second kind of sub-pixels, wherein each of said sub-pixels comprises at least:
a photodiode for converting light to electric signals, an amplifier transistor for amplifying said electric signal, an output transistor for outputting an amplified electric signal, and a reset transistor for resetting a potential of said photodiode; wherein said photodiode is made of said first photodiode in said first kind of sub-pixel or made of said second photodiode in the second kind of sub-pixel.
2. The multispectral imaging device according to claim 1 , wherein, said depletion layer is covered completely by a vertical projection of said second photodiode on a plane of said substrate.
3. The multispectral imaging device according to claim 1 , wherein,
said second photodiode is NIP type, said first photodiode is NP type; or
said second photodiode is PIN type, said first photodiode is PN type.
4. The multispectral imaging device according to claim 1 , wherein,
said second photodiode is PIN type, said first photodiode is NP type; or
said second photodiode is NIP type, said first photodiode is PN type.
5. The multispectral imaging device according to claim 1 , wherein, said second photodiode comprises a first transparent conductive film, an a-Si doped layer of N+ type, an a-Si un-doped layer, an a-Si doped layer of P+ type and a second transparent conductive film.
6. The multispectral imaging device according to claim 1 , further comprising:
an isolating component, arranged between a semiconductor layer and said depletion layer on a plane of said substrate.
7. The multispectral imaging device according to claim 1 , further comprising:
an organic film layer filmed by coating and an insulating layer of field oxide, arranged between said first photodiode and said second photodiode.
8. The multispectral imaging device according to claim 7 , wherein a thickness of said organic film layer is in a range of 1 micrometer to 5 micrometers.
9. The multispectral imaging device according to claim 7 , wherein a relative dielectric constant of said organic film is in a range of 2.5 to 4.
10. The multispectral imaging device according to claim 7 , wherein said depletion layer comprises a N type potential well, and said depletion layer is formed by N− doping and activation with a method of ion implantation between the substrate of P type and said insulating layer.
11. The multispectral imaging device according to claim 7 , wherein said depletion layer comprises a P type potential well, and said depletion layer is formed by P− doping and activation with a manner of ion implantation between a N type substrate and said insulating layer.
12. The multispectral imaging device according to claim 1 , wherein said substrate is N type or P type, and correspondingly, said depletion layer is a hole depletion layer or an electron depletion layer.
13. The multispectral imaging device according to claim 1 , wherein a thickness of said depletion layer is in a range of 2 micrometers to 100 micrometers.
14. The multispectral imaging device according to claim 1 , wherein said detecting array of infrared light image comprises a first photodiode array having depletion layers with at least two kinds of thicknesses.