US 12,261,233 B2Granted

Photodetectors and photodetector arrays

AssigneeActLight SA

InventorsMaxim Gureev, Denis Sallin, Serguei Okhonin

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Abstract

A dynamic photodiode detector or detector array having a light absorbing region of doped semiconductor material for absorbing photons. Electrons or holes generated by photon absorption are detected with a construction of oppositely heavily doped anode and cathode regions and a heavily doped ground region of the same doping type as the anode region. Photon detection involves switching the device from reverse bias to forward bias to create a depletion region enclosing the anode region. When a photon is then absorbed the electron or hole thereby generated drifts under the electric field induced by the biasing to the depletion region where it causes the anode-to-ground current to increase. Furthermore, the detector is configured such that anode-to-cathode current starts to flow once a threshold number of electrons or holes reaches the depletion region, where the threshold may be one to provide single photon detection.

Claims19

Dependent claims

A photodetector device comprising:

a light absorbing region of doped semiconductor material bounded by upper, lower and side surfaces, the light absorbing region being configured to generate pairs of oppositely charged carriers in response to photon absorption;
an anode region composed of a highly doped p-type or n-type semiconductor material and arranged in contact with the light absorbing region;
a cathode region composed of a highly doped n-type or p-type semiconductor material of opposite type to the anode region and arranged in contact with the light absorbing region;
a potential barrier forming region composed of a highly doped n-type or p-type semiconductor material of opposite type to the anode region and arranged between the anode region and the cathode region in contact with the light absorbing region;
and
a ground region composed of a highly doped p-type or n-type semiconductor material of the same types as the anode region and arranged in contact with the light absorbing region;
wherein a depletion region is created in the light absorbing region adjacent the anode region when the device is switched from a reverse bias to a forward bias for sensing, and carriers of appropriate positive or negative charge type generated in the light absorbing region in response to photon absorption are induced by the forward bias to drift towards the depletion region, wherein in response to the carriers reaching the depletion region their associated charges cause a current between the anode and ground regions to increase, such that a threshold number of the carriers arriving at the depletion region is sufficient to induce a further current to start to flow between the anode and cathode regions.

4 more elements

A photosensor array comprising:

a layer of light absorbing region of doped semiconductor material configured to generate pairs of oppositely charged carriers in response to absorption of photons;
an array of detector pixels each having respective anode, cathode, potential barrier forming, and ground regions co-located on a surface of the light absorbing region;
and
a plurality of insulating trenches, filled with dielectric material, extending over side surfaces of the detector pixels to at least partially electrically isolate the detector pixels from each other;
wherein each pixel's anode region is composed of a highly doped p-type or n-type semiconductor material and arranged in contact with the light absorbing region;
wherein each pixel's cathode region is composed of a highly doped n-type or p-type semiconductor material of opposite type to the anode region and arranged in contact with the light absorbing region;
wherein each pixel's potential barrier forming region is composed of a highly doped n-type or p-type semiconductor material of opposite type to the anode region and arranged between the anode region and the cathode region in contact with the light absorbing region;
and
wherein each pixel's ground region is composed of a highly doped p-type or n-type semiconductor material of the same types as the anode region and arranged in contact with the light absorbing region.

6 more elements

Dependencies are inferred from the claim text.

Facts

Application: 18/358,817Filed 25 Jul 2023 · continuation
Priority: 20 Jul 2020
Published: US 2023/0378386 A123 Nov 2023
Granted: 25 Mar 2025
Term ends: Not estimatedThe source records don’t support an estimate.

Classification13 codes

H10F 30/221
The devices having only one potential barrier, e.g. photodiodes: the potential barrier being a PN homojunction
H10F 77/14
Semiconductor bodies: shape of semiconductor bodies; Shapes, relative sizes or dispositions of semiconductor regions within semiconductor bodies
G01J 1/42
Photometry, e.g. photographic exposure meter: using electric radiation detectors
H10F 30/2218
The potential barrier being a PN homojunction: the devices comprising active layers made of only Group IV-VI materials

Family

Application16/933,159Parent of this continuation · filed 20 Jul 2020
US 2023/0378386 A1Pre-grant publication · published 23 Nov 2023
US 11,735,677 B2Parent of this continuation
US 2022/0020886 A1Published application
US 12,261,233 B2This patent

From the US filing history. Foreign family members aren’t listed.