Systems and methods for biasing high fill-factor sensor arrays and the like
View Patent ↗A high fill-factor photosensor array is formed comprising a P-layer, an I-layer, one or more semiconductor structures adjacent to the I-layer and each coupled to a N-layer, an electrically conductive electrode formed on top of the P-layer, and an additional semiconductor structure, adjacent to the N-layer and which is electrically connected to a voltage bias source. The bias voltage applied to the additional semiconductor structure charges the additional semiconductor structure, thereby creating a tunneling effect between the N-layer and the P-layer, wherein electrons leave the N-layer and reach the P-layer and the electrically conductive layer. The electrons then migrate and distribute uniformly throughout the electrically conductive layer, which ensures a uniform bias voltage across to the entire photosensor array. The biasing scheme in this invention allows to achieve mass production of photosensors without the use of wire bonding.
1. A photosensor device to which a voltage is to be applied, comprising:
an intrinsic layer;
a positively doped layer;
an electrically conductive layer over the positively doped layer;
a negatively doped layer adjacent to the insulating layer; and
a negative feedback loop reducing an effective resistance of the selected semiconductor structure, wherein:
the insulating layer, the positively doped layer, the negatively doped layer and the electrically conductive layer are functionally divided into a plurality of semiconductor structures; and
the voltage is applied to a selected one of the plurality of semiconductor structures.
2. The photosensor device of claim 1 , wherein the effective resistance of the selected semiconductor structure is reduced to a negligible value.
3. The photosensor device of claim 1 , wherein the negative feedback loop adjusts an output that drives at least one of the plurality of semiconductor structures to keep a constant voltage applied to the electrically conductive layer.
4. The photosensor device of claim 1 , the negative feedback loop comprising
an operational amplifier,
a source of current, and
a sensing diode.
5. The photosensor device of claim 1 , wherein the photosensor device further comprises a substrate, and the circuit is integrated in the substrate.
6. The photosensor device of claim 1 , wherein the negative feedback loop is wired to a circuit external to the photosensor device.
7. The photosensor device of claim 1 , wherein each semiconductor structure is a diode.
8. The photosensor device of claim 1 , wherein at least the selected semiconductor structure is a diode.
9. A method for applying a voltage to a photosensor device,
the photosensor device comprising:
an intrinsic layer;
a positively doped layer;
an electrically conductive layer adjacent to the positively doped layer; and
a negatively doped layer adjacent to the intrinsic layer; and
a negative feedback loop connected to a selected one of the semiconductor structures,
wherein the intrinsic layer, the positively doped layer, the negatively doped layer and the electrically conductive layer are functionally divided into a plurality of semiconductor structures;
the method comprising:
applying a voltage to a selected semiconductor structure from the plurality of semiconductor structures;
causing drifting of electrons from the negatively doped layer, through the intrinsic layer, and into the positively doped layer;
conducting the drifted electrons to the electrically conductive layer such that the voltage is applied to at least one of the other semiconductor structures; and
reducing an effective resistance of the selected semiconductor structure using the negative feedback loop.
10. The method of claim 9 , wherein the effective resistance of the selected semiconductor structure is reduced to a negligible value.
11. The method of claim 9 , wherein the voltage ranges from −5V to −0.5V.
12. The method of claim 9 , wherein the voltage ranges from −0.5V to 0.5V.
13. The method of claim 9 , wherein the voltage ranges from −0.5V to 1V.
14. The method of claim 9 , the negative feedback loop comprising
an operational amplifier,
a source of current, and
a sensing diode, and
the method further comprising maintaining a voltage at the electrically conductive layer at a constant value.
15. A multi-element semiconductor device to which a voltage is to be applied, comprising:
a plurality of layers, including at least a first electrode layer and a first semiconductor layer, wherein:
the plurality of layers are functionally divided into a plurality of semiconductor structures, the voltage being applied to at least one of the semiconductor structures by the first electrode layer;
a selected one of the semiconductor structures is connected to a voltage source for the voltage, the selected semiconductor structure connecting the voltage source to at least the first electrode layer through at least the first semiconductor layer; and
a negative feedback loop reducing an effective resistance of the selected one of the semiconductor structures.
16. The multi-element semiconductor device of claim 15 , further comprising a grounded guard ring that is part of the multi-element semiconductor device and that is located between the selected one of the semiconductor structures and at least some of the other semiconductor structures.