Classifications

• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
  • G01J1/00—Photometry, e.g. photographic exposure meter
  • G01J1/02—Details
  • G01J1/04—Optical or mechanical part supplementary adjustable parts
  • G01J1/0407—Optical elements not provided otherwise, e.g. manifolds, windows, holograms, gratings
  • G01J1/0429—Optical elements not provided otherwise, e.g. manifolds, windows, holograms, gratings using polarisation elements
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
  • G01J1/00—Photometry, e.g. photographic exposure meter
  • G01J1/42—Photometry, e.g. photographic exposure meter using electric radiation detectors
  • G01J1/44—Electric circuits
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
  • H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
  • H01L27/144—Devices controlled by radiation
  • H01L27/146—Imager structures
  • H01L27/14601—Structural or functional details thereof
  • H01L27/14625—Optical elements or arrangements associated with the device
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
  • H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
  • H01L27/144—Devices controlled by radiation
  • H01L27/146—Imager structures
  • H01L27/14643—Photodiode arrays; MOS imagers
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
  • H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
  • H01L27/144—Devices controlled by radiation
  • H01L27/146—Imager structures
  • H01L27/14643—Photodiode arrays; MOS imagers
  • H01L27/14649—Infrared imagers
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N25/00—Circuitry of solid-state image sensors [SSIS]; Control thereof
  • H04N25/60—Noise processing, e.g. detecting, correcting, reducing or removing noise
  • H04N25/68—Noise processing, e.g. detecting, correcting, reducing or removing noise applied to defects
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N25/00—Circuitry of solid-state image sensors [SSIS]; Control thereof
  • H04N25/70—SSIS architectures; Circuits associated therewith
  • H04N25/709—Circuitry for control of the power supply
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N25/00—Circuitry of solid-state image sensors [SSIS]; Control thereof
  • H04N25/70—SSIS architectures; Circuits associated therewith
  • H04N25/76—Addressed sensors, e.g. MOS or CMOS sensors
• • H—ELECTRICITY
  • H04—ELECTRIC COMMUNICATION TECHNIQUE
  • H04N—PICTORIAL COMMUNICATION, e.g. TELEVISION
  • H04N5/00—Details of television systems
  • H04N5/30—Transforming light or analogous information into electric information
  • H04N5/33—Transforming infrared radiation
• • G—PHYSICS
  • G01—MEASURING; TESTING
  • G01J—MEASUREMENT OF INTENSITY, VELOCITY, SPECTRAL CONTENT, POLARISATION, PHASE OR PULSE CHARACTERISTICS OF INFRARED, VISIBLE OR ULTRAVIOLET LIGHT; COLORIMETRY; RADIATION PYROMETRY
  • G01J1/00—Photometry, e.g. photographic exposure meter
  • G01J1/42—Photometry, e.g. photographic exposure meter using electric radiation detectors
  • G01J1/44—Electric circuits
  • G01J2001/4446—Type of detector
  • G01J2001/448—Array [CCD]
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L27/00—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate
  • H01L27/14—Devices consisting of a plurality of semiconductor or other solid-state components formed in or on a common substrate including semiconductor components sensitive to infrared radiation, light, electromagnetic radiation of shorter wavelength or corpuscular radiation and specially adapted either for the conversion of the energy of such radiation into electrical energy or for the control of electrical energy by such radiation
  • H01L27/144—Devices controlled by radiation
  • H01L27/146—Imager structures
  • H01L27/14601—Structural or functional details thereof
  • H01L27/1463—Pixel isolation structures
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L29/00—Semiconductor devices specially adapted for rectifying, amplifying, oscillating or switching and having potential barriers; Capacitors or resistors having potential barriers, e.g. a PN-junction depletion layer or carrier concentration layer; Details of semiconductor bodies or of electrodes thereof ; Multistep manufacturing processes therefor
  • H01L29/02—Semiconductor bodies ; Multistep manufacturing processes therefor
  • H01L29/06—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions
  • H01L29/0603—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions characterised by particular constructional design considerations, e.g. for preventing surface leakage, for controlling electric field concentration or for internal isolations regions
  • H01L29/0607—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions characterised by particular constructional design considerations, e.g. for preventing surface leakage, for controlling electric field concentration or for internal isolations regions for preventing surface leakage or controlling electric field concentration
  • H01L29/0611—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions characterised by particular constructional design considerations, e.g. for preventing surface leakage, for controlling electric field concentration or for internal isolations regions for preventing surface leakage or controlling electric field concentration for increasing or controlling the breakdown voltage of reverse biased devices
  • H01L29/0615—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions characterised by particular constructional design considerations, e.g. for preventing surface leakage, for controlling electric field concentration or for internal isolations regions for preventing surface leakage or controlling electric field concentration for increasing or controlling the breakdown voltage of reverse biased devices by the doping profile or the shape or the arrangement of the PN junction, or with supplementary regions, e.g. junction termination extension [JTE]
  • H01L29/0619—Semiconductor bodies ; Multistep manufacturing processes therefor characterised by their shape; characterised by the shapes, relative sizes, or dispositions of the semiconductor regions ; characterised by the concentration or distribution of impurities within semiconductor regions characterised by particular constructional design considerations, e.g. for preventing surface leakage, for controlling electric field concentration or for internal isolations regions for preventing surface leakage or controlling electric field concentration for increasing or controlling the breakdown voltage of reverse biased devices by the doping profile or the shape or the arrangement of the PN junction, or with supplementary regions, e.g. junction termination extension [JTE] with a supplementary region doped oppositely to or in rectifying contact with the semiconductor containing or contacting region, e.g. guard rings with PN or Schottky junction

Definitions

• the invention relates to a detection matrix comprising a plurality of photodetectors associated with a reading device.
• the invention also relates to a method of biasing the substrate inside the detection matrix.
• photodetector In the field of detection devices, there is commonly a photodetector associated with a read circuit.
• the photodetector delivers a signal representative of the observed scene and this signal is processed by the read circuit.
• the polarization of the photodetector is obtained by means of the substrate potential imposed on a first terminal of the photodetector and by means of a reference potential imposed on the second terminal of the photodetector by a capacitive transimpedance amplifier type reading device.
• the photodetector In order to obtain more and more information on the observed scene, the photodetector has given way to a plurality of photodetectors. There is, moreover, a constant increase in the number of integrated photodetectors per unit area in a detection device in order to increase the definition of the detector.
• the integration of a large number of photodetectors causes difficulties of implementation and operation.
• the plurality of photodetectors In order to maintain a reasonable collection area and a small size of the device, the plurality of photodetectors is integrated in the form of a matrix.
• An electrically conductive bias ring surrounds the array to impose the substrate potential on the photodetectors of the array.
• the photodetectors are generally inverse polarized photodiodes in order to deliver a current representative of the observed scene.
• the photodiode then plays the role of a current generator.
• the polarization of the photodiode is applied on one side by the substrate and on the other by the read circuit.
• the electrical modeling of a photodiode of the matrix may be represented by a dynamic resistor connected in parallel with the current generator and a series-connected series resistor of the assembly.
• the photodiode production method is not perfect and / or the aging of the photodiodes is not identical for all the photodiodes, which leads to an offset of the polarization conditions of the substrate with respect to the expected integration and / or a drift in time.
• each pixel has a specific polarization pad of the substrate which is particularly restrictive because it strongly limits the integration density of such an architecture.
• a complete line of pixels is sacrificed which makes it very difficult to analyze the scene by the processing circuits.
• only some pixels have a specific polarization pad of the substrate which is as constraining as the embodiment with a polarization pad per pixel.
• the photodetectors are formed by matrix PN junctions.
• the matrix comprises a device for limiting the "crosstalk" by means of a p-type doped zone and an N-type doped zone.
• the subject of the invention is a detection matrix which is more robust with respect to the differences in behavior of the photodetectors. This result is obtained by means of the appended claims and more particularly by the fact that the matrix comprises
• each photodetector being at least partially formed in the substrate forming a first terminal of the photodetectors, a peripheral ring of polarization formed around the matrix of photodetectors, the polarization ring being connected to a bias voltage generator and to the substrate,
• the reading circuits being connected to a second terminal of the photodetectors
• a first switch connected between one of the reading circuits and the second terminal of the associated photodetector in order to allow or block the transmission of an electric current representative of an observed scene
• a second switch connected between an additional voltage generator and the second terminal of said associated photodetector for applying the additional voltage to the second terminal, the first and second switches being in opposite states.
• FIG. 1 schematically represents a detection device with a matrix of photodiodes
• FIG. 2 schematically represents a particular organization of the photodiode array with internal polarization contacts
• the detection device comprises a plurality of photodetectors 1 which are organized in a matrix.
• the photodetectors 1 are organized according to a first axis of organization X, that is to say that the photodetectors 1 form a row or a column along this first axis X.
• the photodetectors are organized along the X axis with a step of P repetition.
• the plurality of photodetectors 1 is also organized according to a second organization axis Y which is secant to the first organization axis X.
• the first axis of FIG. X is perpendicular to the second organization axis Y.
• the photodetectors 1 are organized relative to each other in two different directions represented by the first and the second axis of organization.
• the photodetectors 1 are aligned with each other along one or more lines parallel to the X axis and they are optionally aligned along one or more lines parallel to the Y axis.
• the photodetectors 1 are then organized into rows and columns. .
• Other organizations of the matrix are also conceivable, for example with the integration of two matrices of photodetectors that use different technical characteristics.
• the matrix of photodetectors 1 is formed on a substrate of semiconductor material and is surrounded by a peripheral polarization line 2.
• Line 2 is a line of electrically conductive material, for example a metal line running on the surface of the substrate.
• the line 2 is a doped zone of the substrate, this zone is more heavily doped than the rest of the substrate in order to reduce the potential drop along the line.
• the line 2 is a doped zone which is of the same type of conductivity as the substrate.
• the substrate is of a first type of conductivity, for example of the P type.
• the peripheral line 2 is continuous around the matrix of photodetectors, but it is also conceivable to have a discontinuous line.
• the polarization can also be imposed by means of two elementary lines arranged on two opposite edges of the matrix.
• the peripheral polarization line 2 is connected to a polarization voltage generator 3.
• the VSUB bias voltage or a voltage close to the latter is applied to the photodetectors 1 via the polarization line 2 and the substrate.
• the bias voltage VSUB partially sets the polarization conditions of the photodetectors 1 by applying a first potential to a first terminal (a first electrode) of the photodetector 1.
• the VSUB bias voltage OR a voltage which results therefrom is applied to the first terminal of the different photodetectors 1.
• a second voltage, a reference voltage is applied to a second terminal (a second electrode) of the photodetectors in order to set the polarization conditions of the different photodetectors 1.
• the photodetectors are reverse-biased photodiodes between the VSUB bias voltage and the reference voltage.
• the photodetectors may also be quantum well or quantum well photodetectors (QWIP).
• a second potential is applied via the reading circuit 4 which processes the signal emitted by the photodetector 1.
• the reading circuit 4 is connected to a circuit d analysis 5 of information from the matrix of photodetectors or a part of the matrix, for example a line of photodetectors or a column of photodetectors.
• each photodetector 1 is formed at least partially by a portion of the semiconductor substrate 6.
• the first electrode is formed by the substrate 6 which facilitates the integration of the matrix in the substrate 6 and limit polarization differences.
• the photodetectors are formed in the substrate 6.
• the photodetector 1 is, for example, a PN or NP type photodiode whose first electrode is formed by the substrate 6 which forms a first zone of a first type of conductivity.
• the second electrode is a second zone of a second conductivity type that can also be formed by doping the substrate 6.
• each photodetector 1 is associated with a reading circuit 4 which imposes the reference voltage on the second electrode of the photodetectors 1.
• the different reading circuits 4 are grouped together in order to form means of reading or reading device which includes a read circuit array.
• Each reading circuit 4 is associated with one or more photodetectors 1.
• Each reading circuit 4 retrieves the electrical signal emitted by one or more photodetectors.
• a read circuit 4 is associated with a single photodetector 1 and vice versa.
• a read circuit 4 is associated with a photodetector via a first switch 7.
• the first switch 7 is connected to the second electrode of the photodetector 1 and to the input terminal of the read circuit 4 .
• the second electrode of the photodetector 1 is associated with an additional voltage generator VPOL 9 via a second switch 8.
• the second switch 8 is in a state opposite to the first switch 7 so that the photodetector 1 is biased by means of of the potential imposed by the reading circuit 4 or by means of the additional voltage VPOL coming from the generator 9.
• the photodetector 1 When the second switch 8 is in the on state, the photodetector 1 is biased between the bias voltage V S UB coming from the substrate 1 and the additional voltage VPOL.
• the polarization conditions at the terminals of the photodetector 1 are chosen preferably so that the photodetector 1 has a reduced impact on the other photodetectors of the matrix.
• the photodetector is not connected to the reading circuit 4.
• the generator 9 of the additional voltage VPOL is the generator 3 of the bias voltage VSUB-
• the photodetector 1 when the bias potential VSUB is applied to the second electrode, the photodetector 1 has the same potential on each of its terminals which reduces or eliminates the risk of leakage inside the substrate via this photodetector.
• the VSUB bias potential is applied in the substrate inside the matrix, which makes it possible to improve the general bias conditions of the matrix by promoting the application of the VSUB voltage inside the matrix.
• VSUB polarization potential can also be applied for a healthy photodetector, however, in this case, the photodetector no longer gives information on the observed scene.
• This particular architecture of the matrix allows a simple and effective way to remove a defective photodetector 1 from the matrix during the lifetime.
• the defective pixel is subjected to a set of potentials which reduces its electrical effect vis-à-vis other photodetectors.
• the detection of a defective photodetector can be carried out by means of several different circuits.
• the detection circuit can be part of the analysis circuit which finds that the photodetector exhibits atypical behavior, for example, it returns a fixed value.
• the detection circuit may be part of an ancillary device.
• the detector observes a pattern and a processing circuit analyzes the information emitted by the detector and it discriminates the defective photodetectors.
• This architecture makes it possible to follow in time the evolutions of the photodetectors.
• This architecture is also very malleable vis-à-vis the organization of photodetectors and polarization contacts of the substrate. When the organization of the photodetectors is modified, it is not necessary to redraw the connection to the reading circuits and the polarization sources.
• the different photodetectors are checked in order to know their operating characteristics and / or to know the evolution of these characteristics over time.
• the characteristics of a photodetector exceed a certain threshold, the latter is considered as failing and it can be polarized by means of the additional generator which is comparable to a hole in the detection matrix.
• the series resistance of the photodetector induced by the substrate can cause a modification of the polarization across the photodetectors. Indeed, depending on the intensity of the current generated by the current source, the potential across the photodetector may change.
• the matrix organization of the different photodetectors means that these evolutions of potentials can accumulate and result in the depolarization of one or more photodetectors located in the central part of the matrix and / or subjected to a large luminous flux.
• the substrate is not always able to transport the charge carriers emitted by the different photodetectors 1 to the polarization line 2 which results in a change in conditions. biasing certain photodetectors 1 from the electrode coupled to the substrate.
• the device also comprises one or more electrically conductive point contacts that are connected, on the one hand, to the substrate and, on the other hand, to the 9 additional voltage generator V P OL, here the bias voltage generator 3 V S UB-
• the electrically conductive contacts are formed in the matrix of photodetectors 1 in place of a photodetector 1.
• the contact 10 is connected, via the second switch 8, to a circuit for applying the bias voltage V PO L on the substrate.
• the additional voltage VPOL (here VSUB) is applied to the substrate 6 by putting the second switch 8 in the on state and the first switch 7 in the off state.
• the contact 10 connects the additional voltage generator VPOL with a zone of first conductivity type of the substrate 6.
• the contact 10 comprises an electrically conductive pad 1 1 which interfaces with a zone first conductivity type of the substrate 6 so as to directly apply the additional voltage VPOL in the matrix of photodetectors 1.
• the contacts 1 0 act as direct contacts between the substrate 6, which is an area of the first conductivity type, and the VSUB voltage generator 3.
• the contacts 10 are the relay of the polarization line 2 inside the matrix of photodetectors 1.
• the contacts 10 make it possible to reduce the distance traveled by a charge emitted by the photodetectors 1 to reach the bias voltage VSUB and to be eliminated from the substrate 6.
• the contact 10 may be substantially identical to a photodetector 1.
• the contact 10 and the photodetector 1 each comprise a pad 1 1 electrically conductive.
• this pad 1 1 is deposited on the substrate 6 as for the contact 10. The difference may exist in the doping of the immediately adjacent substrate.
• one end of the pad 1 1 is connected to the reading circuit 4.
• the other end of the pad 1 1 is deposited on an area of the second type of conductivity of the substrate 6 which allows to polarize the photodetector 1, here the diode.
• one end of the pad 1 1 is connected to the generator 9 additional voltage.
• the other end of the pad 1 1 is deposited on the zone 12 of the first conductivity type of the substrate 6 which allows to directly apply the additional voltage V PO L on the substrate 6 and not on a diode.
• the architectures of the contact 10 and the photodetector 1 are similar, common implementation steps can be used to facilitate implementation and maintain a high integration density.
• the pads 11 are formed without taking into account the local nature of the substrate 6, that is to say without knowing whether the substrate forms a contact 10 or a photodetector 1.
• the repeat pitch of the pads is constant.
• the photodetectors are diodes
• the substrate comprises several zones 12 of the second conductivity type which will serve to form the photodetectors 1 and a zone devoid of this doping which will serve to form the contact 10.
• This technological step makes it possible to form an array of zones 12 of the second conductivity type organized along a first alignment axis X and an area of the first conductivity type.
• the zone of the first type of conductivity is aligned with the zones 7 of the second type of conductivity, just like the pads 11.
• the distance separating the zone of the first conductivity type from the two zones of the second conductivity type which are closer together is equal to the repetition pitch that exists between two zones of the second conductivity type.
• the repeat pitch is that of photodetectors 1 in the matrix.
• the stud 11 can be formed for a contact 10 or for a photodetector 1.
• the studs 11 have identical lateral dimensions (length and width) and they can be formed by the same material.
• the pad 11 of electrically conductive material is formed on the zones of the second type of conductivity and the zone of the first type of conductivity.
• the contact 10 Since the electrically conductive contact is formed in place of a photodetector 1, the contact 10 is aligned along the first organization axis X with the other photodetectors 1 of the same column or row.
• a contact 10 has two photodetectors 1 as closest neighbors, on the first axis of organization X. The distance separating the contact 10 from these two closest neighboring photodetectors 1 is equal to the distance separating two adjacent photodetectors 1 according to the first organization axis X.
• two contacts 10 are adjacent and consecutive in one of the organization directions. This embodiment is less interesting than two contacts 10 separated by a few photodetectors.
• the contact 10 is perfectly integrated in the photodetector matrix, its size is identical to that of a photodetector.
• the contacts 10 are distributed at regular intervals along the first organization axis X.
• the distance separating two contacts 10 is an integer multiple of the repetition pitch P of the matrix along the first axis X which can define a first specific repetition step to the contacts 10.
• the repetition distance is chosen so as to prevent the polarization conditions of the photodetectors 1 from being modified beyond a threshold value.
• the repetition distance of the contacts 10 can therefore be defined as soon as the design phase of the device as a function of the polarization conditions applied, the maximum applicable illumination conditions and the electrical properties of the substrate 6.
• a contact 10 or of several electrically conductive contacts 10 in the matrix of photodetectors 1 makes it possible to make the device more robust with respect to the risks of depolarization, for example when the device is subjected to a large luminous flux. .
• the device comprises means for generating the an illumination signal from the photodetectors 1 adjacent to the contact 10.
• a signal for example an image
• the device transmits a signal (For example an image) representative of the scene observed by eliminating the shadow zones created by the contact (s) 10.
• the hole can be likened to a defective photodetector 1 whose position is known in advance, which facilitates the management of the corrections to be made in order to have information associated with each coordinate of the matrix that this zone is occupied. by a photodetector 1 or a contact 10.
• the photodetectors 1 and / or the contacts 10 are connected to a first conductive line which retrieves the information provided by the matrix.
• the first line of metallic material connects the photodetector 1 to the reading circuit 4.
• the reading circuit 4 stores the information delivered by the photodetector and it can also intervene in the polarization of the photodetector 1.
• Each photodetector 1 provides an electrical signal (a voltage or current) that is representative of the observed scene. This signal is conveyed by a power line to information processing means via the reading circuit 4.
• Different types of read circuit are possible, for example direct injection circuits (D1), with direct injection against -Reaction (BDI) or capacitive transimpedance amplifier (CTIA).
• the photodetectors and / or the contacts 10 are also connected to a second conductive line which imposes a particular potential without having the information processing transmitted by the photodetector.
• the photodetectors and the contacts 10 are associated with an additional polarization line which makes it possible to bias the elements of the matrix with a first potential or with a second potential.
• a functional photodetector 1 is normally polarized with a first potential (for example the reference potential imposed by the read circuit) and is connected to the read circuit 4 in order to be able to process the information provided.
• a defective photodetector 1 is normally biased with a second potential to reduce its influence on adjacent pixels. As the pixel is faulty, it is no longer necessary to perform the processing of the transmitted data.
• a contact 10 is normally polarized with the second potential to promote the removal of the charges emitted by the photodetectors directly inside the matrix. Since the contact 10 does not emit a signal as a function of the illumination received, it should not be connected to the reading circuit 4.
• one or more photodetectors of the matrix are associated with a read circuit 4 and the additional voltage generator 9.
• the photodetectors 1 chosen are those which have the greatest probability of failure.
• each photodetector is associated with a read circuit 4 and the additional voltage generator 9. This feature allows corrections to be made throughout the matrix.
• Each photodetector has a second electrode which is connected to an input of a read circuit 4.
• each photodetector 1 is connected to the VSUB bias voltage generator 3 by a second switch 8.
• the photodetector 1 is connected to the reading circuit 4 by a first switch 7 which is in a state opposite to that of the switch 8.
• the integration is similar over the entire matrix of the read circuits 4 which facilitates the integration process.
• the circuit is the same for all photodetectors.
• contacts 10 are integrated in the matrix which allows to have a single read circuit 4 and processing that can be associated with different arrays of photodetectors / contacts.
• the contact 10 is connected to a reading circuit 4 by a first switch 7 and the additional voltage generator 9 by a second switch 8.
• the first and second switches are in opposite states.
• an electrically conductive contact 10 connected to the bias voltage generator 3 is particularly advantageous when the substrate 6 has a high resistivity compared to the illumination conditions accepted by the photodetectors 1.
• This architecture makes it possible to form in the matrix or next to the matrix avalanche photodiodes which is not possible by reversing the types of doping.
• These embodiments are particularly interesting in the where the substrate 6 is a CdHgTe-based material whose electrical characteristics may be insufficient to integrate matrices of large size.
• the use of an electrically conductive contact 10 connected to the bias voltage generator 3 is particularly advantageous when the size of the photodetector array is large.
• an electrically conductive contact 10 connected to the polarization voltage generator is particularly advantageous when the photodetectors 1 are associated with the domains of the long wavelengths of the infrared spectrum (8-15 ⁇ ) which results in the management of a large quantity of charge carriers in the substrate.
• the electrically conductive contact avoids losing a column and / or an entire line of photodetectors.
• the matrix obtained is more compact, that is to say that it comprises a larger number of photodetectors per unit area.
• the matrix of photodetectors 1 may comprise several rows of photodetectors and / or several columns of photodetectors.
• the electrically conductive contacts may be formed on a plurality of different rows or columns.
• the same row or the same column of photodetectors may comprise several electrically conductive contacts.
• the same row or the same column does not have more than one contact 10 in order to reduce the impact of the contact on the information provided by the line and / or the column and thus to reduce the impact. on the treatment of information.
• the photodetector matrix 1 may comprise different organizations of photodetectors 1, for example there is an offset of the photodetectors present on two rows or two successive columns in order to gain compactness. The first and second organization directions are not necessarily perpendicular.
• This architecture is particularly interesting in the case of a bispectral matrix where two types of photodetectors are integrated. Each type of photodetector reacts with a particular wavelength.
• the substrate comprises several layers that react at different wavelengths, which makes it difficult to use the highly doped layer disclosed in WO10815016A1.
• the two types of photodiodes may have different sizes and / or different influences on the electrical properties of the substrate.
• the substrate 6 is of the first type of conductivity and zones 12 of a second type of conductivity are formed inside the substrate.
• the zones 12 of the second conductivity type are spaced from one another.
• each diode has a collection area of the generated carriers that is greater than the area occupied by the zone 12 of the second conductivity type.
• the carriers generated outside the diode can be attracted and collected by the diode.
• the carrier collection surface protrudes from the surface to the second type of conductivity.
• the generated charge carriers have the possibility of being picked up by one or other of the photodetectors 1.
• the photodetectors 1 have identical architectures and identical polarization conditions in order to facilitate the processing of the information emitted by each photodetector 1 in comparison with the other photodetectors 1 of the matrix.
• the photodetectors 1 are considered identical in both their architecture and their operation.
• the photodetectors 1 have the same effective collection area.
• the contact 10 comprises a pad 11 deposited on an area of the first type of conductivity and devoid of an area of the second type of conductivity, there is no formation of a diode or a zone of collection.
• the photodetectors 1 adjacent to a contact 10 have no area of overlap with the contact 10 and they then have an effective collection area which is greater than the other photodetectors 1. There is an offset in the operation of these photodetectors 1 related to the area ⁇
• the electrically conductive contact advantageously comprises a doped zone 13 of the second annular-shaped conductivity type with, at its center, the substrate and / or an area 14. doped first conductivity type which is in electrical continuity with the substrate.
• the electrically conductive contact has a central zone of the first conductivity type and a peripheral zone of the second conductivity type. The zone 13 of the second type of conductivity does not completely surround the zone of the first conductivity type so that the VSUB bias voltage can be applied directly to the substrate and not via a diode.
• This doped zone 13 of the second conductivity type simulates the operation of a photodiode with a collection surface and creates an overlap zone between the contact 10 and each of the adjacent photodetectors 1. This area of overlap reduces the effective collection area of photodetectors 1.
• the pad 1 1 is in electrical contact with the zone 14 of the first type of conductivity and with the zone 13 of the second type of conductivity.
• the zone 14 may be a part of the substrate or part of the zone 13 which has been doped with a type which is subsequently opposed in order to change the conductivity.
• the distance separating the outer edge of the doped zone of the second type of annular conductivity and the doped zone 12 of the second conductivity type of the photodetector 1 is identical to the distance separating two doped zones 12.
• the central zone and the peripheral zone of the contact 10 have opposite conductivity types and these two zones are short-circuited by means of an electrically conductive material, by example a metal, preferably by the pad 1 1 connected to the additional voltage generator.
• This architecture makes it possible to avoid the formation of a diode between the central zone and the peripheral zone of the contact 10 which is detrimental to the proper functioning of the contact 10. This also makes it possible to use the peripheral zone 13 to reduce the collection area. adjacent photodetectors 1 while carrying out the polarization of the substrate 10 at the additional voltage, preferably the bias voltage VSUB by means of the central part of the stud 10.
• the central part of the contact 10, that is to say the zone 14, in the substrate has a higher dopant concentration than the rest of the substrate 6.
• This particular architecture can be achieved simply by forming the matrix of PN or NP diodes in the substrate.
• the zones 12 of the photodiodes and the zone 13 are formed during the same technological step, although it is also conceivable to form them separately.
• a doped zone 14 of the first conductivity type is formed in the zone 13 of the second conductivity type so as to make a direct connection between the substrate 6 of the first conductivity type and the contact pad 1 1 of the contact 10. It is also It is possible to change the formation order of the zones, for example by forming zone 14 first and then forming zones 12 and 13.
• the pads 1 1 are formed in a conventional manner as the rest of the implementation method of the device.
• the pads are for example metal balls which serve to interconnect with a second substrate which comprises the read module. This additional step makes it possible in a simple and economical way to transform a PN or NP diode-type photodetector into a polarization contact integrated directly inside the matrix.
• the contact 10 comprises an area 14 of the first type of conductivity and a zone 13 of the second type of conductivity. These two zones are adjacent and short-circuited in order to be polarized at the same potential, here the bias potential V S UB-
• the first zone 14 of the first conductivity type is in continuous doping with the rest of the substrate 6. From this way, the first zone 14 can not be formed and completely delimited in a box of the second conductivity.
• the conductivity type is constant from the first zone 14 to the substrate.
• the second zone 12 may partially or completely surround the first zone 14 from a lateral point of view in order to have an effect on one or more collection surfaces of the adjacent zones.
• Several zones 13, here zones 13a and 13b, distinct from each other can be formed in front of one or more photodetectors to modify the overlap zone.
• the detector comprises means for applying the bias voltage directly to an area of the first conductivity type which is in continuous doping with the substrate and on an area of the second type of conductivity. This makes it possible to form a diode whose lateral influence will reduce the collection area of at least one adjacent photodetector.

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