WO2016046994A1 - Capteur d'image infrarouge thermique - Google Patents

Capteur d'image infrarouge thermique Download PDF

Info

Publication number
WO2016046994A1
WO2016046994A1 PCT/JP2014/076339 JP2014076339W WO2016046994A1 WO 2016046994 A1 WO2016046994 A1 WO 2016046994A1 JP 2014076339 W JP2014076339 W JP 2014076339W WO 2016046994 A1 WO2016046994 A1 WO 2016046994A1
Authority
WO
WIPO (PCT)
Prior art keywords
diode
heat collector
image sensor
pixels
thermal
Prior art date
Application number
PCT/JP2014/076339
Other languages
English (en)
Inventor
Peter Seitz
Alexandru RUSU
Original Assignee
Hamamatsu Photonics K.K.
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Hamamatsu Photonics K.K. filed Critical Hamamatsu Photonics K.K.
Priority to PCT/JP2014/076339 priority Critical patent/WO2016046994A1/fr
Publication of WO2016046994A1 publication Critical patent/WO2016046994A1/fr

Links

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
    • G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
    • G01J5/10—Radiation pyrometry, e.g. infrared or optical thermometry using electric radiation detectors
    • G01J5/20—Radiation pyrometry, e.g. infrared or optical thermometry using electric radiation detectors using resistors, thermistors or semiconductors sensitive to radiation, e.g. photoconductive devices
    • G01J5/22—Electrical features thereof
    • 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
    • G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
    • G01J5/02—Constructional details
    • G01J5/04—Casings
    • G01J5/046—Materials; Selection of thermal materials
    • 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
    • G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
    • G01J5/02—Constructional details
    • G01J5/08—Optical arrangements
    • G01J5/0853—Optical arrangements having infrared absorbers other than the usual absorber layers deposited on infrared detectors like bolometers, wherein the heat propagation between the absorber and the detecting element occurs within a solid
    • 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
    • G01J5/00—Radiation pyrometry, e.g. infrared or optical thermometry
    • G01J5/10—Radiation pyrometry, e.g. infrared or optical thermometry using electric radiation detectors
    • G01J5/20—Radiation pyrometry, e.g. infrared or optical thermometry using electric radiation detectors using resistors, thermistors or semiconductors sensitive to radiation, e.g. photoconductive devices
    • 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

Definitions

  • the present invention relates to a method and a device for the detection of infrared radiation in the wavelength range of 1 to 100 micrometers, making use of known semiconductor manufacturing processes.
  • the invention relates to an image sensor sensitive to thermal infrared radiation, with a maximum of the emitted spectrum in the wavelength range of 5 to 15 micrometers, which can be manufactured with silicon processes such as the widely used CMOS (Complementary Metal Oxide Semiconductor) technology.
  • CMOS Complementary Metal Oxide Semiconductor
  • thermal IR image sensors Two-dimensional detection of electromagnetic radiation belongs to the most important sensing tasks in science, technology and consumer electronics.
  • a large part of the fabricated image sensors are only sensitive in the visible and near infrared (NIR) spectrum, covering a typical wavelength range of 350 to 1100 nm.
  • NIR near infrared
  • the scenes to be imaged must be actively illuminated to generate contrast between the different objects.
  • passive imaging systems exploiting the thermal emission of electromagnetic radiation from any object whose temperature is nonzero. This can be accomplished with different types of thermal IR image sensors, capable of converting incoming heat energy into an electrical signal, without the need to cool the image sensors.
  • the cheapest approach to thermal IR image sensors consists of so-called pyroelectric arrays.
  • Each picture element (pixel) in such an array consists of a thin sheet of pyroelectric material, characterized in that it changes its internal electrical polarization as a function of its temperature, as described for example by J. Fraden in "Handbook of Modern Sensors", 3 rd edition, Springer 2004. This polarization change can be detected as a voltage or current change, assessed with known electronic measurement circuits.
  • the difficulty of processing most pyroelectric materials and their low temperature sensitivity prevents the production of large numbers of sensitive pixels, exceeding more than a few hundred pixels.
  • thermopile IR image sensors with large numbers of moderately sensitive pixels.
  • Each thermopile pixel consists of a multitude of thermoelectric elements, connected in series or in parallel, as described for example by J. Fraden in "Handbook of Modern Sensors", 3rd edition, Springer 2004. Due to the Seebeck effect, such a thermoelectric element, also called thermocouple, produces a voltage as a function of the temperature difference across the device.
  • IR-sensitive pixels - up to several 100,000 pixels on an IR image sensor - can be fabricated with so-called microbolometer arrays, as described for example by R.K. Bhan et al. in "Uncooled Infrared Microbolometer Arrays and their Characterisation Techniques", Defense Science Journal Vol. 59, pp. 580-589, November 2009.
  • Each microbolometer pixel consists of a thermally insulated heat absorber on top of an electrically conducting material that shows a large resistance change as a function of temperature.
  • a preferred material showing this desired large resistance change as a function of temperature is the widely-used vanadium oxide.
  • vanadium oxide is not a material conventionally used in silicon-based semiconductor processes. For this reason, amorphous silicon (a-Si) is being increasingly used as the sensor material, despite its lower resistance change as a function of temperature compared to vanadium oxide.
  • thermal infrared sensing pixels have been shown that can be fabricated with industry-standard CMOS processes, by exploiting the temperature-dependent reverse-bias current density of a diode structure.
  • CMOS processes by exploiting the temperature-dependent reverse-bias current density of a diode structure.
  • Such a diode can be realized as a pn-homojunction, i.e. a p-doped semiconductor volume in electrical contact with an n-doped semiconductor volume, as described for example by S.
  • the sensitivity of all these pixel types must be maximized, i.e. the intensity of incident infrared radiation must be converted with the highest possible efficiency into an electrical signal.
  • This necessity for maximized device area is particularly well demonstrated in this latter case of diode-based thermal infrared pixels: As described above, the current density of a reverse-biased diode depends approximately exponentially on temperature.
  • the maximum current at a given temperature is obtained when the area of the device is maximized.
  • the forward-bias voltage is proportional to the forward-bias current through the diode, and for maximum voltage and maximum sensitivity, the area of the diode must be maximized, again.
  • NPL 1 "Handbook of Modern Sensors", 3 rd edition, J. Fraden, Springer 2004
  • NPL 2 Uncooled Infrared Microbolometer Arrays and their
  • NPL 3 Low-cost uncooled infrared detectors in CMOS process
  • thermal infrared image sensors consists of thermally insulated pixels with low thermal mass, employing diverse transduction devices with maximum area and therefore exhibiting relatively long thermal time constants. This is accomplished with additional under-etching process steps, increasing the complexity and cost of the semiconductor processes employed for the fabrication of the rest of the thermal infrared image sensor, and reducing the geometrical fill factor of the pixels.
  • thermal infrared image sensors according to the present invention can be fabricated with essentially unmodified CMOS processes, their reaction speed is significantly higher than that of conventional thermally insulated inf ared pixels, and the geometrical fill factor can be increased to close to 100%.
  • the present invention overcomes the above described limitations of thermal infrared image sensors by providing an image sensing device for thermal radiation in the wavelength range of 1 to 100 micrometers.
  • Each pixel consists of a diode structure with minimum dimensions, fabricated as a pn-homojunction in a silicon substrate.
  • the diode is in thermal contact with a heat-collecting structure of significantly larger area than the diode.
  • the heat collector is thermally and electrically insulated from the rest of the substrate, using an insulator material with low electrical and low thermal conductivity such as silicon dioxide.
  • the heat collector is fabricated from a material with high thermal conductivity such as aluminum or copper, and its surface is treated to be an efficient infrared absorber.
  • Incident infrared radiation is collected by the heat collector and increases the temperature of the diode.
  • the local temperature at each pixel site is determined.
  • a preferred way to achieve this is reverse-biasing the diode, letting the temperature-dependent current discharge the diode and measuring the resulting voltage difference.
  • a multitude of such infrared pixels can be arranged in one- or two-dimensional arrays to form line or area sensors for thermal infrared radiation.
  • These infrared sensors can be fabricated with essentially unchanged industry-standard CMOS processes, and their operation does not require cooling.
  • This invention may provide a thermal inf ared image sensor that can be fabricated with an industry-standard semiconductor fabrication process based on silicon, such as the widely used CMOS processes.
  • Fig. 1 shows a cross section of the thermal infrared sensing device according to one embodiment of the present invention. It consists of a pn-homojunction diode in a silicon substrate, in thermal contact with a heat collector structure, which is thermally and electrically insulated from the rest of the substrate.
  • Fig. 2 shows a perspective drawing of one embodiment of the heat collector structure, realized as a rectangular slab of a material with high thermal conductivity, provided with a plug with high thermal conductivity, through which the flow of thermal energy is guided into the sensing diode, increasing its temperature and causing thus a measurable electrical effect in the diode.
  • Fig. 3 shows a first embodiment of an electrical circuit with which the temperature-dependent current of a sensing diode is measured. It consists of an operational amplifier working as a transconductance circuit, converting the diode's reverse-bias current into a voltage signal.
  • Fig. 4 shows a second embodiment of an electrical circuit with which the temperature-dependent current of a sensing diode is measured. It consists of an operational amplifier working as a charge integrator circuit, integrating the diode's reverse-bias current during a given exposure time. This circuit produces a voltage signal that is proportional to the integrated number of charge carriers provided by the diode's current.
  • Fig. 5 shows a fourth embodiment of an electrical circuit with which the temperature-dependent current of a sensing diode is measured.
  • the diode is connected at the sense node to a source follower transistor and a reset transistor, through which the diode is reverse-biased. During the exposure time, the reverse-biased diode is discharged through the diode current, and the voltage difference is measured with the source follower.
  • Fig. 6 shows a fifth embodiment of an electrical circuit with which the temperature-dependent current of a sensing diode is measured. It consists of the same source-follower circuit shown in Fig. 5, whose sense node is connected to an offset current source. Through this current source, a part of the diode's reverse-bias current can be sunk, increasing the dynamic measurement range of the source-follower circuit.
  • Fig. 7 shows one embodiment of the circuit shown in Fig. 6, in which a single transistor is acting as the pixel's offset current source during integration, and acting as a switch during the reset operation, through which the sense node is recharged to the reset voltage Vc-
  • Fig. 8 shows one embodiment of an electrical circuit with which the temperature-dependent current of a forward-biased sensing diode is measured. It consists of an operational amplifier working as a transconductance circuit, converting the diode's forward-bias current into a voltage signal.
  • Fig. 9 shows one embodiment of an electrical circuit with which the temperature-dependent constant-current voltage of a forward-biased sensing diode is measured.
  • the diode is connected at the sense node to a source follower transistor and a current source, realized in this example as a single transistor in saturation.
  • the current source forces a current through the diode, which reacts by adapting the voltage at the sense node. This temperature-dependent voltage is measured with the source follower transistor.
  • Fig. 10 shows the cross section of an alternative embodiment of the thermal infrared sensing device according to the present invention.
  • a thin electrical insulator between the heat collector structure and the sensing diode reduces the effective electrical capacitance at the sense node, thereby reducing the measurement noise of the output signal.
  • Fig. 11 shows an example of a schematic diagram of a thermal infrared image sensor, making use of thermal infrared sensing pixels according to one embodiment of the present invention. It consists of a multitude of such pixels, for example of the type illustrated in Fig. 5, that are arranged in n rows and m columns.
  • the pixels are individually addressable with a row encoder and a column multiplexer, producing a voltage signal at the image sensor's output which is a monotonous function of the local temperature at each pixel's diode.
  • a further object of the invention is to provide a thermal infrared image sensor consisting of a plurality of pixels with a geometrical fill factor close to 100%.
  • Another object of the invention is to provide a thermal infrared image sensor consisting of a plurality of pixels exhibiting a response speed exceeding the one provided by known infrared pixel types making use of under-etching techniques for thermal insulation and reduction of thermal mass.
  • Yet another object of the invention is to provide a thermal infrared image sensor whose pixels can be made so small that it is possible to fabricate thermal infrared image sensors with a resolution exceeding one megapixel using industry-standard mask reticles.
  • a final object of the invention is to provide a thermal infrared image sensor with an improved measurement dynamic range, by supplying each pixel with electronic means to cancel offset signals observed at a reference temperature.
  • the present invention is achieved with an image sensor consisting of a plurality of infrared sensitive devices, so-called pixels, illustrated in Fig. 1.
  • Each pixel with lateral extent P is fabricated on a silicon substrate 1 (silicon substrate part) as pn-homojunction, acting as a diode 2.
  • the diode 2 is in thermal contact with a heat collector 4.
  • the heat collector 4 is electrically and thermally insulated from the silicon substrate 1 through the insulator layer 3.
  • the insulator layer 3 is interposed between the silicon substrate 1 and the heat collector 4 so as to insulate the heat collector 4 from the underlying silicon substrate 1.
  • the heat collector 4 is a three-dimensional structure consisting of an upper slab 6, absorbing and converting the incident infrared radiation into heat and a plug structure 7, concentrating and guiding this heat energy into the diode 2 and then raising its temperature correspondingly.
  • the heat collector 4 consists of a material with high thermal conductivity k c , whose top surface is treated with known techniques such that it absorbs incident infrared radiation.
  • the shape of the slab 6 can be square, as illustrated in Fig. 2, it can be rectangular, polygonal, circular, ellipsoidal, or it can have any other connected form.
  • the insulator layer 3 consists of an electrically insulating material that exhibits also low thermal conductivity k t . That is, a thermal conductivity ki of the insulator layer 3 is lower than a thermal conductivity k c of the heat collector 4. An electrical conductivity of the insulator layer 3 is also lower than an electrical conductivity of the heat-collector 4.
  • This thermal infrared sensor overcomes the sensing performance of a conventional diode-based infrared sensing device whose diode area w is about the same as the area W 2 of the infrared radiation absorber, i.e. w 2 ⁇ W 2.
  • incident infrared radiation is absorbed by the absorber element, which increases the temperature at the diode site.
  • the area W of the absorber and heat collector structure is significantly larger than the area w 2 of the diode, so that most of the heat energy generated by the absorption of the incident radiation is channeled into a much smaller area of the silicon substrate.
  • a diode width w is significantly larger.
  • a second requirement follows from the condition that more heat should flow laterally through the slab 6 into the plug 7 than into the substrate 1 through the insulation layer 3. This is satisfied by inequality 2: k t W ⁇ 8 k c d D, with d indicating the thickness of the slab 6 and D indicating the thickness of the insulation layer 3, as illustrated in Fig. 2.
  • a preferred material for the insulator layer 3 is silicon dioxide whose thermal conductivity k t is 1.3 W/(m* K).
  • a preferred material for the heat collector structure 4 is aluminum, whose thermal conductivity k c is 204 W/(m* K), or copper, whose thermal conductivity is 385 W/(m* K).
  • thermal infrared sensing device 10 can be read out in several ways:
  • the temperature-dependent diode current I(T) can be measured with a known transconductance amplifier, preferentially realized with the operational amplifier 11 and employing
  • Voltage Vs at the operational amplifier's positive input terminal determines the bias voltage across the diode.
  • the temperature-dependent diode current I(t) can be integrated during a certain exposure time t exp , as illustrated in Fig. 4, and the integrated charge Q - I(T) xt exp shows the same temperature dependence as the diode current itself.
  • Voltage 5 at the operational amplifier's positive input terminal determines the bias voltage across the diode.
  • Reset transistor 14 is switched on for a short time, in order to reverse-bias the device's diode at the sense node to reverse-bias voltage Vs. Consequentially, capacitance C is charged to the same voltage V s . Afterwards, reset transistor 14 is switched on off, in order to leave the sense node electrically floating, and a first measurement V outl is acquired with source follower transistor 13.
  • the temperature-dependent diode current 1(1) discharges capacitance C during the exposure time t exp leading to measurement result V ou t2 of the source follower transistor.
  • FIG. 7 A very space-efficient realization of the circuit shown in Fig. 6 is illustrated in Fig. 7, where single transistor 16 is used, alternately, as a current source and as a reset transistor.
  • transistor 16 When used as a current source, transistor 16 is operated in saturation and in the sub-threshold regime. In this mode, the current through transistor 16 is virtually independent of source-drain voltage, as required from a current source, and it depends exponentially on programming voltage VRC at the gate of the transistor 16.
  • VRC programming voltage
  • the transistor 16 When used as a reset switch, the transistor 16 is supplied with a voltage VRC that is so low (in the case of a p-MOS transistor) that the transistor 16 is operated in linear mode, i.e. it is acting as a switch with a certain internal resistance.
  • the process-dependent reverse-bias current of the diode is so low that its shot noise leads to excessive noise in the output signal.
  • I 0 is a process- and geometry-dependent constant
  • q is the unit charge
  • V indicates the diode's forward voltage
  • k is Boltzmann's constant
  • T indicates the temperature
  • m is the diode's ideality factor, typically varying between 1 and 2.
  • V mkT/q x ln(I( Ic).
  • a preferred embodiment of a circuit measuring this temperature-dependent voltage is illustrated in Fig. 9. It consists of the current source 16, preferentially implemented as a single transistor operating in saturation mode, connected in series with forward-biased sensing diode in thermal contact with the heat collector 17.
  • the forward current I c of the current source 16 is programmed using gate voltage V R C.
  • the forward-biased diode reacts by adapting the voltage on the sense node connected to the gate of the source-follower transistor 13. As a consequence, output voltage V out at the source of transistor 13 is linearly dependent on the sought temperature T.
  • capacitance C is as low as possible for maximum voltage signals for a given amount of integrated charge Q.
  • the heat collector structure 4 in Fig. 1 is also a good electrical conductor, the electrical contact between the heat collector 4 and the diode 2 leads to an increased capacitance at the sense node in the circuits of Figs. 5 to 9. This effect can be mitigated and the total capacitance C at the sense node can be reduced by placing the thin electrical insulator 5 between the heat collector structure 4 and the diode 2, as illustrated in Fig. 10. Thickness t of the electrical insulator 5 must be small enough that the heat flow into the diode 2 is not obstructed significantly. This is the case if the thermal conductance of electrical insulator 5 is larger than the thermal conductance of heat collector plug 7, i.e. k/t > kc/D, with k t indicating the thermal conductivity of the electrical insulator layer 5.
  • the electrical insulator 5 can also be fabricated between the top of the heat collector plug 7 and the heat collector slab 6. This can be technologically accomplished, for example, by fabricating the thermal and electrical insulator 3 over the substrate 1 and the heat collector plug 7 on the diode 2, and by subsequently depositing an electrical insulation layer of thickness t over the plug area, and possibly over the complete area of thermal and electrical insulator 3.
  • the required semiconductor process is not an industry-standard process any more but rather an extension of it, raising the fabrication complexity and cost of these thermal infrared image sensors.
  • the low thermal conductance of the infrared sensor element results in a rather long thermal time constant of typically a few 10 ms. As a consequence, it is not possible to acquire fast-changing thermal scenes with a frame rate exceeding 100 Hz.
  • the sensitivity of the thermal infrared sensor device according to our invention is not achieved by low thermal conductance and low thermal mass of the sensor element, it is rather based on concentration of the heat energy to a small diode area and by creating an uneven temperature distribution with its maximum at the diode site. Due to the direct thermal contact to the substrate of our infrared pixels, they have a much shorter time constant than conventional infrared pixels, allowing the acquisition of higher frame rates of thermal infrared imagery with our thermal infrared image sensors.
  • temporal averaging at each pixel site can be carried out, which reduces the electronic readout noise according to a square root dependence of the number of measurements averaged.
  • the thermal infrared sensor device according to the present invention can be fabricated with industry-standard silicon-based processes, in particular with the widely used CMOS processes. All of these processes allow the fabrication of electrical conductors over electronic circuits produced in the silicon substrate, appropriately protected with an insulating layer between circuitry and conductors. As a consequence, the heat collector structure of our thermal infrared sensor device can reach over the electronic readout circuitry, providing for an effective geometrical fill factor of close to 100%.
  • a multitude of thermal infrared sensing devices can be arranged in n rows and m columns, with n>l and m>l and « *m>7, forming a thermal infrared image sensor.
  • This multitude of pixels can be read out using one or more output lines, making use of known electronic circuits for addressing pixels and reading out the image sensor.
  • FIG. 11 An example of the schematic diagram of such a thermal infrared image sensor with rolling shutter is illustrated in Fig. 11 , employing, as an example, the thermal infrared pixel according to the present invention shown in Fig. 5.
  • the sources of all source follower transistors in the selected row of pixels are connected each to its own column transistor 22, whose gates are connected to common bias voltage V b ias, such that the column transistors 22 are operated as active loads.
  • V b ias common bias voltage
  • the source follower readout circuit is completed for all pixels in the selected row, and a voltage appears at the drain of the column transistor 22 that is proportional to the local discharge state of each pixel in the row.
  • the column multiplexer 23 is used to read out the pixels' signals through the output buffer or the amplifier 24. Each pixel value appearing as V out at the image sensor's output is digitized and stored for further processing.
  • the reset values of all pixels in the selected row are read out again using the column multiplexer 23 and the output amplifier or the buffer 24.
  • Each pixel reset value appearing as V out at the image sensor's output is digitized and stored for processing. This processing consists of waiting during the exposure time until the same row is selected again and the signal pixel values of this row are read out. For each pixel in this row, the previously acquired and stored pixel reset value is subtracted from the newly acquired signal pixel value, thus producing a pixel value with reduced kTC noise contribution, as known for the double-sampling noise reduction technique.
  • the photosensor according to this invention includes a plurality of pixels, and each of the plurality of pixels includes the silicon substrate 1, the diode 2, the heat collector 4 and insulator layer 3.
  • the diode 2 is fabricated on the silicon substrate 1.
  • the heat collector 4 is thermally contacted with the diode 2.
  • the heat collector 4 includes an upper slab 6 that absorbs the infrared radiation and a plug 7.
  • the upper slab 6 converts the incident infrared radiation into heat and guiding this heat into the plug 7.
  • the heat is guided into the diode 2 through the plug 7 and raises the temperature of the diode 2
  • the insulator layer 3 is interposed between the silicon substrate 1 and the heat collector 4 and insulates the heat collector 4 from the underlying silicon substrate 1.
  • the thermal conductivity k of the insulator layer 3 is lower than the thermal conductivity k c of the heat collector 4, and the area W of the slab 6 of the heat collector 4 is larger than the area w 2 of the diode 2 or the plug 7 of the heat-collector 4, the area W 2 of slab 6 of the heat collector 4 is in corresponding to the pixel area.

Landscapes

  • Physics & Mathematics (AREA)
  • General Physics & Mathematics (AREA)
  • Spectroscopy & Molecular Physics (AREA)
  • Engineering & Computer Science (AREA)
  • Power Engineering (AREA)
  • Electromagnetism (AREA)
  • Condensed Matter Physics & Semiconductors (AREA)
  • Computer Hardware Design (AREA)
  • Microelectronics & Electronic Packaging (AREA)
  • Transforming Light Signals Into Electric Signals (AREA)
  • Photometry And Measurement Of Optical Pulse Characteristics (AREA)

Abstract

L'invention concerne un dispositif de détection d'image pour un rayonnement thermique dans la plage de longueur d'onde de 1 à 100 micromètres, qui est composé d'une multitude de pixels. Chaque pixel se compose d'une structure de diode (2) avec des dimensions minimales, fabriquée sous la forme d'une homojonction pn dans un substrat de silicium (1). La diode est en contact thermique avec une structure de collecte de chaleur (4) ayant une surface considérablement plus grande que celle de la diode. Le collecteur de chaleur est isolé thermiquement et électriquement du reste du substrat, à l'aide d'un matériau isolant (3) à faible conductivité thermique et à faible conductivité électrique, tel que le dioxyde de silicium. Le collecteur de chaleur est fabriqué à partir d'un matériau à haute conductivité thermique, tel que l'aluminium ou le cuivre, et sa surface est traitée pour être un absorbeur infrarouge efficace. Un rayonnement infrarouge incident est collecté par le collecteur de chaleur et augmente la température de la diode. En mesurant le courant de diode, la température locale au niveau de chaque site de pixel est déterminée. Une façon préférée de l'obtenir est la polarisation inverse de la diode, la possibilité pour le courant dépendant de la température de décharger la diode, et la mesure de la différence de tension résultante. Ces pixels de capteur infrarouge thermique offrent un temps de réaction rapide et des facteurs de remplissage géométriques proches de 100 %.
PCT/JP2014/076339 2014-09-25 2014-09-25 Capteur d'image infrarouge thermique WO2016046994A1 (fr)

Priority Applications (1)

Application Number Priority Date Filing Date Title
PCT/JP2014/076339 WO2016046994A1 (fr) 2014-09-25 2014-09-25 Capteur d'image infrarouge thermique

Applications Claiming Priority (1)

Application Number Priority Date Filing Date Title
PCT/JP2014/076339 WO2016046994A1 (fr) 2014-09-25 2014-09-25 Capteur d'image infrarouge thermique

Publications (1)

Publication Number Publication Date
WO2016046994A1 true WO2016046994A1 (fr) 2016-03-31

Family

ID=51743528

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/JP2014/076339 WO2016046994A1 (fr) 2014-09-25 2014-09-25 Capteur d'image infrarouge thermique

Country Status (1)

Country Link
WO (1) WO2016046994A1 (fr)

Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4282290A (en) * 1980-01-23 1981-08-04 The United States Of America As Represented By The Secretary Of The Air Force High absorption coating
JP2002171142A (ja) * 2000-12-05 2002-06-14 Rohm Co Ltd 受光装置
US20030038332A1 (en) * 2000-01-12 2003-02-27 Kimura Mitsuteru A Method and apparatus for temperature measurement, and themal infrared image sensor
US20040200962A1 (en) * 2003-04-11 2004-10-14 Mitsubishi Denki Kabushiki Kaisha Thermal type infrared detector and infrared focal plane array
US20110068860A1 (en) * 2009-09-22 2011-03-24 Societe Francaise De Detecteurs Infrarouges - Sofradir Detection circuit with improved anti-blooming circuit
WO2012082801A2 (fr) * 2010-12-13 2012-06-21 The Board Of Regents For Oklahoma State University Détecteur infrarouge thermoélectrique à nanofils

Patent Citations (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US4282290A (en) * 1980-01-23 1981-08-04 The United States Of America As Represented By The Secretary Of The Air Force High absorption coating
US20030038332A1 (en) * 2000-01-12 2003-02-27 Kimura Mitsuteru A Method and apparatus for temperature measurement, and themal infrared image sensor
JP2002171142A (ja) * 2000-12-05 2002-06-14 Rohm Co Ltd 受光装置
US20040200962A1 (en) * 2003-04-11 2004-10-14 Mitsubishi Denki Kabushiki Kaisha Thermal type infrared detector and infrared focal plane array
US20110068860A1 (en) * 2009-09-22 2011-03-24 Societe Francaise De Detecteurs Infrarouges - Sofradir Detection circuit with improved anti-blooming circuit
WO2012082801A2 (fr) * 2010-12-13 2012-06-21 The Board Of Regents For Oklahoma State University Détecteur infrarouge thermoélectrique à nanofils

Non-Patent Citations (2)

* Cited by examiner, † Cited by third party
Title
ASHOK SOOD ET AL: "Design considerations of ROIC for single color LWIR and multicolor IR focal plane arrays", PROCEEDINGS OF SPIE, vol. 6294, 31 August 2006 (2006-08-31), pages 62940A, XP055203890, ISSN: 0277-786X, DOI: 10.1117/12.684641 *
MASAFUMI KIMATA ET AL: "<title>SOI diode uncooled infrared focal plane arrays</title>", PROCEEDINGS OF SPIE, vol. 6127, 9 February 2006 (2006-02-09), pages 61270X, XP055195651, ISSN: 0277-786X, DOI: 10.1117/12.640339 *

Similar Documents

Publication Publication Date Title
Bhan et al. Uncooled infrared microbolometer arrays and their characterisation techniques
US7489024B2 (en) TMOS-infrared uncooled sensor and focal plane array
US9887339B2 (en) Infrared sensor, thermal imaging camera and method for producing a microstructure from thermoelectric sensor rods
US7847253B2 (en) Wideband semiconducting light detector
Lee et al. A high fill-factor infrared bolometer using micromachined multilevel electrothermal structures
Teranishi Effect and limitation of pinned photodiode
US20120085990A1 (en) Superlattice quantum well infrared detector having exposed layers
JP4257989B2 (ja) 赤外線検出装置及びそれを用いた赤外線検出器アレイ
JP6178429B2 (ja) 赤外線放射のため半導体光センサ
JP2018500577A (ja) 感知装置
JP2009238985A (ja) 半導体撮像素子およびその製造方法
Wada et al. YBaCuO uncooled microbolometer IRFPA
US9658110B1 (en) Thermal sensor combination
Ali et al. Graphene Field-Effect-Coupled Detection of Avalanche Multiplication in Silicon
US7884329B2 (en) Device and method for detecting electromagnetic radiation
KR20080085798A (ko) 적층형 열화상 센서장치
KR20210002555A (ko) 픽셀 당 다크 기준 볼로미터
Ramakrishna et al. Performance of titanium and amorphous germanium microbolometer infrared detectors
WO2016046994A1 (fr) Capteur d&#39;image infrarouge thermique
US8212214B2 (en) Solid-state imaging element
JP2006177712A (ja) 半導体装置及びその製造方法
Kim et al. Development of microbolometer with high fill factor and high mechanical stability by shared-anchor structure
JP2005188970A (ja) 熱型赤外線固体撮像装置および赤外線カメラ
Zviagintsev et al. Self-heating effects in CMOS-SOI-NEMS transistors for uncooled passive IR sensors
Teranishi Thermoelectric uncooled infrared focal plane arrays

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 14786370

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 14786370

Country of ref document: EP

Kind code of ref document: A1