EP2340422A1

EP2340422A1 - Bolometric detector for detecting electromagnetic waves

Info

Publication number: EP2340422A1
Application number: EP09797567A
Authority: EP
Inventors: Patrick Agnese; Agnès ARNAUD
Original assignee: Commissariat a lEnergie Atomique CEA; Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
Current assignee: Commissariat a lEnergie Atomique et aux Energies Alternatives CEA
Priority date: 2008-07-17
Filing date: 2009-05-28
Publication date: 2011-07-06
Also published as: WO2010007266A1; FR2934044A1; US20110057107A1; FR2934044B1

Abstract

This bolometric detector for detecting electromagnetic radiation comprises: a receive antenna (10) designed to collect the electromagnetic radiation, and thus ensure electromagnetic coupling; a resistive load (30) capacitively coupled to the antenna (10) and capable of converting the collected electromagnetic power into calorific power; and a thermometric element (40) connected to the resistive load (30) and thermally isolated from a support substrate capable of receiving an electronic circuit integrating electrical excitation (stimulus) means and means for preprocessing the electrical signals generated by said detector. The resistive load (30) is suspended above the receive antenna (10) by means of just the thermometric element (40), which is itself electrically and mechanically connected to the support substrate.

Description

BOLOMETRIC DETECTOR OF ELECTROMAGNETIC WAVES

TECHNICAL AREA

The invention relates to a bolometric detector, more particularly intended to perform the detection of electromagnetic waves from the infrared range to the visible range or beyond, that is to say to detect electromagnetic waves of lengths. wave of a few micrometers to the submillimeter range (a few hundred micrometers), or even millimeter.

The detection of millimeter waves and more particularly submillimetric waves presents a certain number of interests in particular on the scientific and technical level. Among the known application areas are space sensing, astrophysics in particular, but also imagers, radio astronomy from ground telescopes, biomedical imaging, etc.

Two different physical principles are essentially known for the detection of millimeter and submillimeter waves.

The first of these consists in detecting the electromagnetic waves by means of an antenna so as to create an electrical signal, the processing of which is carried out by an electronic circuit operating at the frequency of the wave. The disadvantage of detectors operating according to this first principle is to be strongly limited in frequencies.

In addition, since such detectors are generally arranged in a matrix structure, the corresponding circuits generate a relatively high heat dissipation, of the order of 1 Watt for a 32x32 matrix, constituting another disadvantage.

The second known technical principle is to implement an electromagnetic wave detection antenna, capable of creating a heat flow, the measurement of which corresponds to the desired signal. The detectors used in the context of this principle are traditionally constituted by the family of bolometric detectors. In known manner, the thermal detectors, to which family the bolometric detectors belong, absorb the power of an incident electromagnetic radiation, convert it into heat, which is then transformed into a signal resulting from the correlative temperature rise with respect to a reference temperature, in a given range, for associating with these temperature variations electrical signals corresponding to the actual measurement of the incident electromagnetic flux. However, it is conceivable that as soon as a low temperature variation is measured, the detector must be as thermally isolated as possible.

Under the effect of the incident radiation, the detector heats up and transmits the correlative temperature rise to the sensitive thermometric material. This increase in temperature causes a variation of a property of said sensitive material, such as an appearance of electric charges by pyroelectric effect, the variation of the capacitance by changing the dielectric constant for the capacitive detectors, the variation of the effect voltage. thermoelectric for thermocouples, and the variation of resistance for bolometric detectors.

In the field of infrared detection, the use of bolometric detectors is widespread. These detectors are conventionally constituted by a suspended membrane, which comprises a thin layer (typically between 0.1 and 1 micrometer) made of a temperature-sensitive bolometric material, two electrodes and an absorber, the function of which is to pick up the electromagnetic radiation for the convert into heat within the structure thus defined. The membrane is suspended by means of beams above the support substrate via anchor points or fixing pins, suitable for isolating said membrane from the substrate. These anchor points or fixing pins also called pillars, can bring the excitation potentials or stimuli to the conductive parts or electrodes of the bolometric detector via flat and elongated structures, also called arms or isolation beams. These arms are electrically conductive but on the other hand must have the highest possible thermal resistance.

In order to achieve satisfactory performance, the bolometric material, that is to say the sensitive material, must have a low heat content, must be well thermally insulated from the support, and finally must have a high sensitivity to warming conversion effect to electrical signal. In known manner, the support substrate, generally made of silicon, receives a read circuit consisting of an electronic circuit integrating means for sequentially addressing or multiplexing the elementary detectors and electrical excitation means, for example stimuli. , and pre-processing the electrical signals generated by said elementary detectors. In doing so, such a read circuit makes it possible to serialize the signals coming from the different elementary detectors and to transmit them to a small number of outputs, in order to be exploited by a usual imaging system, such as for example an infrared camera.

Advantageously, in order to optimize the performance of these detectors, they are encapsulated under vacuum or under very low gas pressure within a housing, then provided with a transparent window in the wavelength band concerned.

Traditionally, the bolometric material used consists of polycrystalline or amorphous silicon of the p or n type, which is weakly or strongly resistive, but can also be made of vanadium oxide (V ₂ O 5, VO ₂ ) or of a cuprate (YBaCuO) produced in a semiconductor phase.

The implementation of such bolometric detectors has been widely described in relation to the detection in the infrared domain. For this wavelength range, it is possible to simultaneously combine the thermometric and absorption functions of the incident infrared radiation on the bolometric plate.

Indeed, an electromagnetic detection system must have dimensions close to the order of magnitude of the wavelength considered in order to be effective. There is a tradeoff between the collected power (proportional to the surface of the detector) and the spatial resolution. The diffraction phenomena inherent in any optical system limit the spatial resolution to a value of the order of the wavelength in the dimensions of the plane. The optimal dimensions for a detector are therefore of this order of magnitude.

Thus, a board or array of infrared detectors of dimensions 25 x 25 microns ² is likely to integrate these two functions. In doing so, the absorber, that is to say the membrane supporting the bolometric sensitive element provides both the electromagnetic coupling function with the incident radiation, and therefore the absorption of said radiation, and the conversion function of this radiation. heat flux radiation by Joule effect. However, in the submillimeter wavelength or millimetric wavelength range, the previous reasoning would lead to membranes of the same order of magnitude. However, both the heat mass, the mechanical strength and the radiation losses of a membrane of such dimensions are unthinkable for the durability of the detectors implemented in addition to the quality of the measurements to be made.

In doing so, it becomes necessary to separate the electromagnetic coupling function from the conversion function of the electromagnetic power into heating power. The first of these two functions is performed by means of a receiving antenna, and the second function is provided by a resistive load associated with the antenna.

PRIOR STATE OF THE TECHNIQUE

Such bolometric detection devices known as "antenna" are known, capable of operating at temperatures around 300 K, therefore at ambient temperature, but also capable of operating at cryogenic temperatures (up to T <1 Kelvin). These devices implement arrays or matrices of such detectors.

FIG. 1 shows a diagram illustrating the operating principle of such an antenna bolometer of the prior art.

It basically consists of an antenna (1) consisting of a conductive layer deposited on a non-conductive substrate (2). It comprises a resistive metal (3) constituting both the resistive load of the antenna, suitable for generating the heating power, and the insulating arms of a thermometer or bolometer (4), composed of a thermo-thermal material. resistive, such as for example amorphous silicon or vanadium oxide. As can be seen, it is defined under the thermometer (4) a cavity (5) for thermal insulation thereof.

The electric currents generated in the antenna (1) by the incident radiation are dissipated in the insulation arms (3) by joule effect.

Advantageously, a reflective metal plane optimizes the absorption for a given range of wavelengths. This reflector is generally positioned at a distance equal to λ / 4n of the antenna, λ being the average wavelength to be detected and n being the refractive index of the medium separating the reflector from the antenna, and this in order to optimize the coupling in the antenna. It is well understood the need to thermally isolate the actual detector, in this case made of bolometric material, to allow optimization of the detection. One of the difficulties to overcome with such detection devices lies in the limitation imposed by construction, related to the proportionality between the thermal conductance and the electrical conductance in any conductive material, and which takes a simple form for the metals: the law of Wiedmann Franz.

Thus, the electrical connection between the antenna and the thermometer is necessarily accompanied by a thermal link, which significantly impairs the performance of the bolometers, since they also measure a variation in temperature with respect to a value. reference.

In WO 00/40937, for example, a detection device has been described, implementing such antenna bolometers. The described "Bow-Tie" type antenna (bow tie) is placed above a metal plane at a distance equal to one quarter of the detector's operating wavelength, thereby defining a so-called cavity. quarter wave ", well known in itself. In addition, the suspension of the thermometer is constituted by the load resistance of the antenna. The thermometer consists of a monocrystalline silicon junction diode whose thermal insulation results from the etching of the silicon substrate on the rear face.

The antenna of particular shape is deposited on a layer of silicon oxide SiO, which because of the technology used (thin film type) has a thickness e of the order of a micrometer. A "Bow-Tie" type antenna, optimized to detect around a frequency of 1 THz has a size of about half of the operating wavelength, ie 150xl50μm ² .

The antenna is, in this case, almost to the thermal mass; in other words, it is not thermally insulated, and because of its mechanical and electrical connection with the thermometer, it is not thermally insulated satisfactorily.

In order to overcome this drawback, it has been proposed in document US Pat. No. 6,329,655, a detection device also implementing a bolometric detector. The antenna is of the same type as that of the previous document (bow tie), but a capacitive or inductive coupling is also introduced between the antenna and the load resistor. The coupling is done in the center of the antenna. The thermometer or bolometer used is of the type thermistor with preferentially Vanadium oxide V2O5. This coupling, however, requires a sub-micron space between the antenna and the thermometer, which significantly complicates the technology for producing such a detector.

Again, the antenna is not thermally insulated, only the constituent thermo-resistive material of the thermometer is effectively thermally insulated from the substrate, and decoupled from the antenna for capacitive optical coupling.

It has also been suggested in document FR 2 855 609 to position a reflector plane placed under the bolometer at a distance strictly less than one quarter of the wavelength of use. The load resistance of the antenna is then of the order of kΩ, which corresponds to a still insufficient thermal resistance, limiting the performance of the detector. In addition, such a high load resistance value is necessarily accompanied by a decrease in the width of the absorption band, which is disadvantageous for a passive detector, the power absorbed being proportional to the bandwidth .

To optimize the thermal insulation sought, it has been proposed in document FR 2 884 608, a bolometric detector of the type in question in which the receiving antenna is itself isolated from the support substrate. This solves the problems of thermal insulation of the thermometer. However, the problem remains, on the one hand, the reduction of the response time of such detectors, and on the other hand, the miniaturization of the detectors, constituting a permanent concern of the person skilled in the art, without affecting the properties of detection.

SUMMARY OF THE INVENTION

The invention relates to a bolometric detector for electromagnetic radiation comprising: - a receiving antenna for collecting electromagnetic radiation and thus ensuring electromagnetic coupling; a resistive load capacitively coupled to the antenna and adapted to convert the collected electromagnetic power into heating power; a thermometric element connected to the resistive load and thermally isolated from a support substrate, the latter being capable of receiving an electronic circuit integrating electrical excitation means (stimuli) and pretreatment of the electrical signals generated by said detector.

According to the invention, the resistive load is suspended above the receiving antenna by means of the single thermometric element, itself electrically and mechanically connected to the support substrate.

In other words, the invention consists in using as a thermometer the mechanical suspension element of the structure that is traditionally composed of the resistive load and the thermometer, thus making it possible to reduce the size of the bolometer (resistive load + thermometer), and of this is its heat capacity, and therefore improve its temporal response.

Advantageously, the resistive load is central with respect to the thermometric element. In doing so, the heating power arising from the capacitive coupling of the receiving antenna with said load and transmitted to the thermometric element is also centered, the heat diffusing along said element on either side of the load. At the level of said thermometric element, a temperature gradient is created between this centralized position and the ends of the thermometric element, which is inherent to the very nature of the material which constitutes it.

According to another advantageous characteristic of the invention, the resistive load is of square or rectangular shape. In the latter case, the largest dimension of the rectangle is oriented along the main direction of extension of the antenna. It has a surface close to a few square microns, and preferably less than 10 microns ² . More generally, the surface of the resistive load is advantageously less than 1% of the surface of the receiving antennas.

According to the invention, the support substrate receives a layer of a reflective material separated from the antenna by a dielectric material, an insulating semiconductor, an organic material, or by vacuum. In the latter case, the antenna is maintained by support means relative to the substrate, and for example by dielectric pillars. In doing so, an optical cavity is created whose thickness is of the order of λ / 4n, where n is the retraction index of the medium constituting the cavity, and λ is the average wavelength of the detection domain considered. .

According to an advantageous characteristic of the invention, the antenna is in the form of a "bow-tie" (bow tie), or double bow-tie (to take into account the two directions of polarization at 90 ° of the incident wave ) and its capacitive connection with the resistive load is made in the vicinity of its center, that is to say the convergence zone of the elements that constitute it, substantially located in the center of the pixel in question.

The antenna is advantageously made of metal layer of low square resistance, and for example selected from a material consisting of Al, AlCu, AlSi, Ti.

According to another characteristic of the invention, the resistive load and the thermometric element which suspends it are separated from the antenna by an air gap or an insulation vacuum, or even an inert gas, in order to constitute the capacitive coupling. between resistive load and antenna. In this way, the thermal insulation of the thermometer is favored.

The resistive load is advantageously made of titanium nitride and has a thickness of a few nanometers and a size much smaller than that of the antenna, so a very low heat capacity.

Finally, the thermometric element is advantageously made of bolometric material, in particular made from amorphous silicon or from vanadium or iron oxide. It is held at its ends on pillars able to serve as electrical contacts with the support substrate integrating the read circuit and as already said means of electrical excitation and pretreatment of electrical signals generated by the detection of an electromagnetic wave . The thermometric element is however thermally isolated from said support by vacuum and the fact that the thermometer, constituting the suspension, can be very electrically resistive, so thermally, and of very small section to reduce the thermal conduction by phonons.

Advantageously, within the same pixel, a bolometer sensitive to the electromagnetic radiation to be detected, of the type previously described, is associated with a compensation bolometer that is insensitive to said radiation, also referred to as "blind". The implementation of such a compensation bolometer is in itself known and makes it possible to overcome the common mode current. Such compensating bolometers, which are insensitive to incident optical fluxes, are however sensitive to the temperature of the substrate. It generates in a known manner a so-called compensation current that is subtracted from the current from the imaging bolometer, that is to say the detection bolometer through the configuration of the electronic circuit. As a result, most of the so-called "common mode" current, that is to say not representative of the information coming from the scene to be detected, resulting from the support substrate of electrical or thermal origin is eliminated.

BRIEF DESCRIPTION OF THE FIGURES

The manner in which the invention can be realized and the advantages which result therefrom will emerge more clearly from the exemplary embodiment which follows, given by way of indication and not limitation, in support of the appended figures.

Figure 1 is as already said a schematic representation of an antenna bolometric detector according to the prior art.

Figure 2 is a schematic representation in section of a detector according to the invention, Figure 3 is a view from above.

FIG. 4 is a view from above of an advantageous version of a detector according to the invention.

EMBODIMENT OF THE INVENTION

FIG. 2 is a diagrammatic sectional view of an electromagnetic radiation detector in accordance with the invention. A pixel constituting such a detector has more particularly been represented.

This is reported on a support substrate (20), typically composed for example of a silicon oxide SiO layer and a solid silicon Si substrate.

This substrate is also capable of being etched with a read circuit according to a CMOS technology well known to those skilled in the art.

Is deposited on this substrate (20) a layer (50) for constituting a reflector. This consists of metal layers of low square strength, for example made of materials selected from the group consisting of Al, AlCu, AlSi, Ti. In known manner, a such reflector is intended to reflect the wavelengths to be detected. This reflector is deposited on the substrate (20) by sputtering, evaporation, CVD ("Chemical Vapor Deposition") or other technique for depositing thin-layer metal layers.

Advantageously, it fills the surface of the pixel as much as possible. In some particular cases, it can be structured, in particular when the device is made on the reading circuit or when it also plays the role of electrical contact and more particularly interconnection of the thermometer to the outside of the chip or the underlying reading circuit.

An optical cavity (70) with a thickness λ / 4n is then defined, in which n is the refractive index of the medium constituting said cavity. This creates between the antenna (10) deposited on said cavity and the reflector (50), a "quarter wave" blade well known to those skilled in the art to optimize the absorption in the range of lengths d wave considered.

This cavity has a minimum absorption in the considered wavelength spectrum that is sought to be detected by the antenna (10) itself. It should be noted that any loss in the cavity occurs at the expense of maximum absorption in the antenna load. It is typically constituted by a dielectric (SiO, SiN, etc.) but may also consist of silicon, organic material (polyimide, benzocyclobutene-based polymer), or even vacuum. The thickness of this optical cavity is determined by the specifications of the detector in particular in terms of band width, absorption wavelengths and the material that constitutes it. This thickness can typically vary from one micrometer to several tens of microns.

In addition, in the particular case of detectors made on the reading circuit, this cavity must also allow the realization of a first portion of the pillars and more specifically a first portion of the electrical contacts (60) adapted to ensure the reading of the resistance bolometric in the pixel by said read circuit. In known manner, the electrical contacts (60) consist of an electrically conductive material such as titanium nitride or tungsten silicide. This material is deposited by CVD ("Chemical Vapor Deposition"), for example. The purpose of these pillars is twofold: they are intended to provide a support function of the bolometer from a mechanical point of view on the one hand, and secondly, they are intended to serve as electrical contacts with the support substrate integrating the reading circuit. In the latter case, they make it possible to electrically connect the bolometer and the support substrate, and in particular the bolometer and the reading circuit.

As indicated above, an antenna (10) is deposited on this cavity, for example by PVD ("Physical Vapor Deposition" ie by spraying) opposite the reflector (50). This antenna is also made of metal layers of low square resistance, for example of the same nature as the reflector. It is further structured to allow detection of the electromagnetic wave (Bow-Tie, spiral ...).

According to an essential characteristic of the invention, a resistive load (30), intended to ensure the capacitive coupling of the current of the antenna generated by the electromagnetic wave, is suspended above the antenna (10) by means of a thermometric element, constituted in this case by a bolo metric material (40), thus acting as beam or suspension bar. In fact, because of this suspension, it is created between the antenna (10) and the assembly consisting of the bolometer (40) and the resistive load (30) a blade of air, inert gas or vacuum.

As can be seen from the figures, the resistive load (30) is centered with respect to the thermometric element (40).

Technically, the establishment of the resistive load (30), the bolometric layer (40) and a second portion of the electrical contacts (90) is performed subsequent to the deposition of a sacrificial layer (not shown) intended to be removed after completion of the detector. This sacrificial layer is preferably organic (polymer), so as to allow its removal under oxygen or ozone (plasma or not) without damaging the other materials present (it goes without saying that the materials can be passive for avoid their oxidation).

However, this sacrificial layer may also be made of amorphous carbon whose oxygen etching is also compatible. It may optionally be made of porous oxide which can then be removed by hydrofluoric acid in the vapor phase. It should be noted that for the realization of an empty cavity under antenna maintained by pillars, one can use this same sacrificial layer method The thickness of the air or vacuum plate (80) thus generated is typically between 0.1 and a few micrometers. And for the case of the empty cavity, the thickness will obviously be the distance between antenna and reflector.

The aforementioned resistive load (30) consists of a material of a few hundred Ω / square, typically 200-400 Ω / square and of very small thickness, so as to minimize the heat content of the detector according to the invention. . This resistive load can be made of titanium nitride a few nanometers thick, deposited by spraying on the sacrificial layer mentioned above. It is located opposite the antenna (10) and more precisely in view of the convergence zones of said antenna when it is of "Bow-Tie" shape. It should be noted that in this embodiment, the second portion of the electrical contacts (90) is made of the same material as the resistive load.

This load can be square or rectangular. As can be seen in FIG. 4, in the case of a rectangular configuration, the large dimension of the rectangle extends in the direction of the antenna, and more particularly in the direction of deployment of the antenna. when it is bow tie shaped.

The bolometric material (40) intended to act as a thermometer is therefore, as shown in FIG. 2, in contact with the resistive load (30). As already said, this bolometric material (40) is intended to heat up depending on the electromagnetic flux absorbed by the load coupled to the antenna / cavity / refiector assembly. It is typically made of amorphous silicon or oxide, especially vanadium or iron, so as to have a T _cr coefficient of a few% per degree, representing in a known manner the variation of the resistance as a function of temperature. Typically, it has a coefficient T _cr close to 2% / ° celcius.

According to one characteristic of the invention, the bolometric material (40) is in the form of a beam or a bar, as can best be seen in Figure 3, further ensuring the suspension function the resistive load (30) above the antenna (10) and the optical cavity (70).

As will have been understood, the beams or bars (40) constituting the bolometric material ensure not only the mechanical suspension of the resistive load (30), but also the thermal insulation and the thermometric electrical resistance. Insofar as the heat capacity of said resistive load (30) is reduced, said beams (40) can be of higher thermal resistance while maintaining a high thermal bandwidth.

In the surface of an optical pixel with a pitch of 30 μm, comprising nine antennas, said antennas may be of a different nature, so as to allow polarized detection in TE (transverse electric) mode and TM (transverse magnetic) mode, and / or a detection in two or three spectral bands (even if they overlap) by the play of the thickness of the optical cavity, and / or by interrelation of the measurements, furthermore making it possible to reject the original common mode noise electric or thermal.

In imaging, a point of the observed scene can be detected by the optics of the instrument on a so-called optical pixel (image point), comprising for example 3x3 antennas at a pitch of 10 μm (depending on the range of wavelengths considered) . By construction, these antennas can be different, for example of the "Bow-Tie" type in one direction. The polarization of the flux emitted by the scene is then measured in the perpendicular direction. The antennas of the optical pixel may further be of different size. Thus each of the antennas can detect in different wavelength bands: multispectral principle of visible color detector (RGB, red green blue).

One of the antennas may be blind, that is to say that the corresponding bolometer does not heat up by the stream received, it is then a so-called compensation bolometer (see below). The differential measurement is made between this bolometer and the other bolometers of the optical pixel, thus making it possible to reject common mode noise or noise.

Since the antenna pitch is less than the wavelength, for widely open optics (focal length F close to 1) and limited by diffraction, the spatial sampling of the image is correct or even super-resolved. In addition, large die sizes can be achieved by minimizing the cost (especially by reducing the silicon area).

Indeed, for an optical aperture of 1 (ratio of the focal length F to the diameter of the lens D) the diffraction is 1.22 λ .F / D, and the sampling is correct according to the Shannon criterion if the pixel pitch optical is half of the diffraction spot. For applications in which the detector is exposed to ionizing particles (in the space domain, in particular), the antenna and the reflector are not sensitive to such particles, and the sensitive area (resistive load and beams) is made of particularly reduced surface. For an optical pixel of 3x3 antennas, we can identify one of the calorimeters touched by a particle or a high energy photon, and thus realize the average of the measurements on the others, the gain is 8/9 compared to zero for a sensor filling the optical pitch.

By relaxed stress of the beams or polarization of the reflector, it is possible to induce a controlled electrostatic force on the load, and thus to adjust or modulate the capacitive coupling, that is to say the distance of the air-gap, and thus the coupling optical structure.

This changes the spectral response of the bolometer.

Indeed, during the realization of the detector according to the invention, is deposited successively on a sacrificial layer, for example polyimide, the antenna (SiN), the thermometer, and also the resistive load (TiN) in the center of the beam. This set of layers is constrained (in compression or extension) on the polyimide layer, on the one hand, because of the temperature variations during the implementation of the deposition process (heating, then return to ambient temperature) and, on the other hand, because of the removal of said polyimide sacrificial layer.

When removing the latter, the beam is released into the air, and may bend towards the antenna, or otherwise away from it. In doing so, the air gap is modified, that is to say the distance between the beam or the load and the antenna, and corollary, the capacitive coupling between the load and the antenna. This air gap is filled by an electrostatic force between the reflector and the load.

According to an advantageous characteristic of the invention and as illustrated in FIG. 4, a sensitive bolometer (100), also called a compensation bolometer, is associated with the sensitive bolometer.

As stated in the preamble, such a compensating bolometer makes it possible to reject the common-mode current resulting from the signal emanating from the substrate (20) and consequently to retain as the processed signal only that coming from the detected scene. In this configuration, the compensation bolometer (100) is not associated with a resistive load. In addition, it is not associated with an antenna.

Claims

A bolometric detector of electromagnetic radiation comprising: a receiving antenna (10) for collecting electromagnetic radiation and thereby providing electromagnetic coupling; a resistive load (30) capacitively coupled to the antenna (10) and adapted to convert the collected electromagnetic power into heating power; a thermometric element (40) connected to the resistive load (30) and thermally insulated from a support substrate (20) capable of receiving an electronic circuit integrating electrical excitation means (stimuli) and pre-processing the electrical signals generated by said detector; characterized in that the resistive load (30) is suspended above the receiving antenna (10) by means of the single thermometric element (40), itself electrically and mechanically connected to the support substrate (20).

Bolometric detector of electromagnetic radiation according to claim 1, characterized in that the resistive load (30) is centered with respect to the thermometric element (40).

3. bolometric detector of electromagnetic radiation according to one of claims 1 and 2, characterized in that the resistive load (30) is square or rectangular, the largest dimension of the rectangle extending in the main direction of extension of the antenna (10)

Bolometric detector for electromagnetic radiation according to one of Claims 1 to 3, characterized in that the resistive load (30) has an area less than 1% of the area of the receiving antenna (10).

Electromagnetic radiation bolometric detector according to one of claims 1 to 4, characterized in that the support substrate (20) receives a layer of a reflective material (50) separated from the receiving antenna (10). by an optical cavity (70), made of a dielectric material, semiconductor, organic, or constituted by vacuum.

6. bolometric detector of electromagnetic radiation according to claim 5, characterized in that the thickness of the optical cavity (70) is of the order of λ / 4n, n being the refractive index of the medium constituting the cavity. , and λ, the average wavelength of the detection domain considered.

7. bolometric detector of electromagnetic radiation according to one of claims 1 to 6, characterized in that the receiving antenna (10) is in the form of "bow-tie" (bow tie), or double bow-tie , or in spiral, and in that the capacitive connection between said antenna and the resistive load (30) takes place in the vicinity of the center of the antenna, that is to say of the convergence zone of the elements that constitute it.

8. Bolometric detector of an electromagnetic radiation according to one of claims 1 to 7, characterized in that the receiving antenna (10) consists of metal layer of low square resistance, preferably made of a material selected from the group comprising Al, AlCu, AlSi, Ti ,.

9. bolometric detector of electromagnetic radiation according to one of claims 1 to 8, characterized in that the resistive load (30) and the thermometric element (40) which suspends it above the receiving antenna (10) are separated from said antenna by an air gap or an insulation vacuum, or even an inert gas.

10. bolometric detector of electromagnetic radiation according to one of claims 1 to 9, characterized in that the resistive load (30) is made of titanium nitride and has a thickness of a few nanometers.

11. bolometric detector of an electromagnetic radiation according to one of claims 1 to 10, characterized in that the thermometric element (40) is made of bolometric material, preferably selected from the group comprising amorphous silicon and vanadium oxides and iron.

12. bolometric detector of electromagnetic radiation according to one of claims 1 to 9, characterized in that the thermo metric element (40) is in the form of a beam or bar, held at its ends on pillars (60, 90) in electrical contact with the support substrate (20) but thermally isolated therefrom.

13. Bolometric detector of an electromagnetic radiation characterized in that it associates within the same pixel a bolometer sensitive to the electromagnetic radiation to be detected according to one of claims 1 to 10 to a compensation bolometer (100), insensitive said radiation, and intended to reject the common mode current resulting from the support substrate (20) of electrical or thermal origin.