Bolometer-type infrared detector and method for manufacturing the same

Abstract

To provide a bolometer-type infrared detector with a high TCR value and a method of manufacturing the same.SOLUTION: Disclosed is a bolometer-type infrared detector comprising a substrate, a bolometer film comprising semiconducting carbon nanotubes, and two electrodes spaced from each other and connected to the bolometer film, where at least one of the two electrodes is formed of a metal alloy comprising at least two metals selected from the group consisting of Li, Be, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, In, Sn, Sb, Ba, La, Hf, Ta, Ir, Pt, Au, and Bi.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] This invention relates to a bolometer-type infrared detector and a method for manufacturing the same. [Background technology]

[0002] Infrared sensors have a very wide range of applications, including not only security surveillance cameras but also thermography of the human body, in-vehicle cameras, and inspection of structures, food, etc., and their industrial applications have been active in recent years. In particular, there is a great demand for the development of inexpensive and high-performance uncooled infrared sensors that can acquire biometric information in conjunction with IoT (Internet of Things). Conventional uncooled infrared sensors mainly use VO2 in the bolometer portion. x Vanadium oxide is used, but the process is costly due to the need for heat treatment under vacuum, and the temperature coefficient of resistance (TCR) is small (approximately -2.0% / K), which are challenges.

[0003] To improve TCR (Total Temperature Cross-Resolution), materials with large resistance changes in response to temperature changes and high conductivity are required. Therefore, semiconducting single-walled carbon nanotubes with large band gaps and carrier mobility are expected to be applied to the bolometer portion. Furthermore, because carbon nanotubes are chemically stable, inexpensive device fabrication processes such as printing can be applied, potentially enabling low-cost, high-performance infrared sensors.

[0004] For example, Patent Document 1 proposes a method for producing a bolometer using an inexpensive thin-film process, in which ordinary single-walled carbon nanotubes are applied to the bolometer portion, and a dispersion is prepared by mixing them with an organic solvent, taking advantage of the chemical stability of the single-walled carbon nanotubes, and then coating the electrode with the dispersion. In this process, the TCR was successfully improved to approximately -1.8% / K by annealing the single-walled carbon nanotubes in air.

[0005] Single-walled carbon nanotubes usually contain semiconducting carbon nanotubes and metallic carbon nanotubes with a ratio of 2:1, so there is a problem that separation is necessary. Therefore, in Patent Document 2, since single-walled carbon nanotubes contain a mixture of metallic and semiconducting components, chirality-aligned semiconducting single-walled carbon nanotubes are extracted using an ionic surfactant and applied to the bolometer part, successfully achieving a TCR of -2.6% / K.

Prior Art Documents

Patent Documents

[0006]

Patent Document 1

Patent Document 2

Summary of the Invention

Problems to be Solved by the Invention

[0007] However, in the carbon nanotube thin film used for the infrared sensor described in Patent Document 1, since there are many metallic carbon nanotubes mixed in the carbon nanotubes, the TCR is low in the room temperature region, and there is a limit to improving the performance of the infrared sensor. In addition, the TCR value of the infrared sensor using the semiconducting carbon nanotubes described in Patent Document 2 is not sufficient for high sensitivity, and there is a problem that further improvement of the carbon nanotube film is required.

[0008] In view of the above problems, an object of the present invention is to provide a bolometer-type infrared detector capable of realizing a high TCR value and a method for manufacturing the same.

Means for Solving the Problems

[0009] One aspect of the present invention is a substrate, a bolometer film containing semiconducting carbon nanotubes, and Two electrodes are bonded to the bolometer film at a distance from each other. It has at least the following features: A bolometer-type infrared detector in which at least one of the two electrodes is formed of an alloy containing at least two metals selected from the group consisting of Li, Be, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, In, Sn, Sb, Ba, La, Hf, Ta, Ir, Pt, Au, and Bi. Regarding.

[0010] Another aspect of the present invention is, The process of preparing the circuit board, A process of forming a bolometer film containing semiconductor carbon nanotubes on a substrate, A step of forming two electrodes before or after the step of forming the bolometer film, such that the two electrodes are joined to the bolometer film at a distance from each other, wherein at least one of the two electrodes is formed of an alloy containing at least two metals selected from the group consisting of Li, Be, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, In, Sn, Sb, Ba, La, Hf, Ta, Ir, Pt, Au, and Bi. A method for manufacturing a bolometer-type infrared detector, including Regarding. [Effects of the Invention]

[0011] According to the present invention, a bolometer-type detector that can obtain a high TCR value can be provided. [Brief explanation of the drawing]

[0012] [Figure 1] This is a plan view of a bolometer element according to one embodiment of the present invention. [Figure 2] This graph shows the relationship between voltage and current (293K) and the relationship between voltage and TCR (293K-303K) for a device with near-linear IV characteristics. [Figure 3]This graph shows the relationship between voltage and current (293K) and the relationship between voltage and TCR (293K-303K) in an element with nonlinear IV characteristics. [Figure 4] This is a longitudinal cross-sectional front view showing the cell structure of a bolometer according to one embodiment of the present invention. [Figure 5] This is a longitudinal cross-sectional front view showing the cell structure of a bolometer according to one embodiment of the present invention. [Figure 6] This is a plan view showing the structure of a bolometer array according to one embodiment of the present invention. [Figure 7] This is a longitudinal cross-sectional front view showing the cell structure of a bolometer according to one embodiment of the present invention. [Figure 8] This is a longitudinal cross-sectional front view showing a method for manufacturing a bolometer according to one embodiment of the present invention. [Figure 9] This is a process diagram showing a method for manufacturing a bolometer array according to one embodiment of the present invention. [Figure 10] This is a plan view showing the structure of a bolometer array according to one embodiment of the present invention. [Figure 11] This is a longitudinal front view showing the cell structure of a bolometer according to one embodiment of the present invention, and a plan view showing the array structure. [Figure 12] This is the composition of the binary alloy predicted by a machine learning model. [Figure 13] This is the composition of the binary alloy predicted by a machine learning model. [Figure 14] This is the composition of the binary alloy predicted by a machine learning model. [Figure 15] This is the composition of the binary alloy predicted by a machine learning model. [Modes for carrying out the invention]

[0013] The inventors have found that in a bolometer-type detector using a bolometer film containing carbon nanotubes, the degree of bonding between the carbon nanotubes and the contact electrode greatly affects the TCR, and in particular, that a higher TCR can be obtained by using an alloy of two or more metals selected from the group consisting of Li, Be, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, In, Sn, Sb, Ba, La, Hf, Ta, Ir, Pt, Au, and Bi as the material for the electrode that contacts the bolometer film.

[0014] The configuration of a bolometer-type infrared detector equipped with contact electrodes according to this embodiment is described below. As shown in Figure 1, the bolometer-type infrared detector of this embodiment comprises at least a substrate 1, a bolometer film 3 (CNT film) formed on the substrate 1, and two contact electrodes 2 and 4 provided in contact with the bolometer film 3 (CNT film). Conventionally, in CNT transistors and the like, metals such as Au, Ti, and Pt are used as the contact electrode material to obtain good ohmic junctions. In the current-voltage characteristics (IV characteristics) when an ohmic junction is formed between the CNT film and the contact electrodes, generally, as shown in Figure 2 left, the IV curve at a positive bias voltage and the IV curve at a negative bias voltage are symmetrical, and the TCR is usually constant and voltage-independent, as shown in Figure 2 right. On the other hand, the inventors discovered that when the contact electrode material is selected such that the bonding between the CNT film and the contact electrode is a Schottky junction, the IV characteristics show asymmetry between positive and negative voltages, as shown in Figure 3 left, and the TCR changes depending on the voltage, as shown in Figure 3 right, and for example, a particularly large TCR can be obtained on the negative side where current flow is difficult. The bonding between the CNT film and the contact electrode is complexly influenced by the work function of the material as well as the interface state (surface state), but it was found that by using an alloy combining two or more metals for the electrode, it is possible to appropriately adjust the TCR to obtain a large TCR.

[0015] (Contact electrodes) Of the two contact electrodes connected to the bolometer film, at least one may be formed of an alloy, but usually both are preferably formed of an alloy. Also, the same alloy or different alloys may be used for the two contact electrodes.

[0016] As the alloy constituting the electrode, the inventors constructed machine learning models such as Random Forest, MLPregressor, and sklern_fabn using the work function and electrical resistivity data obtained from experiments and simulations as target variables, and predicted the composition of the binary alloy for which the values of both target variables would be preferable values (Figs. 12 to 15), thereby identifying the alloy composition suitable for use in the electrodes of the bolometer-type infrared detector of the present embodiment. Specifically, the alloy constituting the electrode preferably contains two or more metals selected from Li, Be, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, In, Sn, Sb, Ba, La, Hf, Ta, Ir, Pt, Au, and Bi, and more preferably contains at least one selected from Al, Cu, Ag, and Au. The alloy composition is not particularly limited. For example, in a two-terminal element, the alloy composition of each electrode can be determined in order to create a junction state in which the height of the Schottky barrier and the like at each of the two electrodes is controlled.

[0017] Also, the alloy used for the electrodes of the bolometer-type infrared detector is desired to have a desired work function and at the same time a low electrical resistivity. Examples of alloys that satisfy the desired work function and electrical resistivity are shown below.

[0018] <Alloy containing Al> For the purpose of making the electrical resistivity 500 nΩm or less, preferably 100 nΩm or less, and making the work function of the alloy higher than 5.0 eV, it is preferable to contain at least one selected from Pd, Pt, and Au. For the purpose of having an electrical resistivity of 500 nΩm or less and a work function of the alloy between 4.5 eV and 5.0 eV, it is preferable to contain at least one selected from Fe, Co, Ni, Cu, Mo, Ru, Rh, Pd, Ag, Sn, Sb, Ir, Pt, Au, Bi. More preferably, for the purpose of having an electrical resistivity of 100 nΩm or less and a work function of the alloy between 4.5 eV and 5.0 eV, it is preferable to contain at least one selected from Fe, Co, Ni, Cu, Mo, Ru, Rh, Pd, Ag, Sb, Ir, Pt, Au. Similarly, for the purpose of having an electrical resistivity of 500 nΩm or less, preferably 100 nΩm or less, and a work function of the alloy between 4.0 eV and 4.5 eV, it is preferable to contain at least one selected from Be, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Ag, In, Sn, Sb, Hf, Ta, Bi. Similarly, for the purpose of having an electrical resistivity of 500 nΩm or less, preferably 100 nΩm or less, and a work function of the alloy lower than 4.0 eV, it is preferable to contain at least one selected from Li, Y, Zr, Ba, La, Hf, Ta.

[0019] <Alloy containing Cu> For the purpose of having an electrical resistivity of 500 nΩm or less, preferably 100 nΩm or less, and a work function of the alloy higher than 5.0 eV, it is preferable to contain at least one selected from Pd, Pt, Au. For the purpose of having an electrical resistivity of 500 nΩm or less, preferably 100 nΩm or less, and a work function of the alloy between 4.5 eV and 5.0 eV, it is preferable to contain at least one selected from Be, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, Zr, Nb, Mo, Ru, Rh, Pd, Ag, In, Sn, Sb, Hf, Ta, Ir, Pt, Au, Bi. Similarly, for the purpose of having an electrical resistivity of 500 nΩm or less and a work function of the alloy between 4.0 eV and 4.5 eV, it is preferable to contain at least one selected from Li, Al, Ti, V, Mn, Zn, Y, Zr, Nb, In, Ba, La, Hf, Ta. More preferably, for the purpose of having an electrical resistivity of 100 nΩm or less and a work function of the alloy between 4.0 eV and 4.5 eV, it is preferable to contain at least one selected from Li, Al, Mn, Zn, Y, Nb, In, Ba, La, Ta. Similarly, for the purpose of having an electrical resistivity of 500 nΩm or less and a work function of the alloy lower than 4.0 eV, it is preferable to contain at least one selected from Li, Y, Zr, Ba, La, Hf. More preferably, for the purpose of having an electrical resistivity of 100 nΩm or less and a work function of the alloy lower than 4.0 eV, it is preferable to contain at least one selected from Li, Ba.

[0020] <Alloy containing Ag> For the purpose of having an electrical resistivity of 500 nΩm or less, preferably 100 nΩm or less, and a work function of the alloy higher than 5.0 eV, it is preferable to contain at least one selected from Pd, Pt, Au. For the purpose of having an electrical resistivity of 500 nΩm or less, preferably 100 nΩm or less, and a work function of the alloy between 4.5 eV and 5.0 eV, it is preferable to contain at least one selected from Be, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Rh, Pd, In, Sn, Sb, Hf, Ta, Ir, Pt, Au, Bi. Similarly, for the purpose of having an electrical resistivity of 500 nΩm or less and a work function of the alloy between 4.0 eV and 4.5 eV, it is preferable to contain at least one selected from Li, Be, Al, Ti, V, Mn, Zn, Y, Zr, Nb, In, Ba, La, Hf, Ta. More preferably, for the purpose of having an electrical resistivity of 100 nΩm or less and a work function of the alloy between 4.0 eV and 4.5 eV, it is preferable to contain at least one selected from Li, Be, Al, Ti, Mn, Zn, Y, Zr, Ba, La, Hf, Ta. Similarly, for the purpose of making the electrical resistivity 500 nΩm or less and the work function of the alloy less than 4.0 eV, it is preferable to contain at least one selected from Li, Y, Zr, Ba, La, and Hf. More preferably, for the purpose of making the electrical resistivity 100 nΩm or less and the work function of the alloy less than 4.0 eV, it is preferable to contain at least one selected from Li and Ba.

[0021] <Alloy containing Au> For the purpose of making the electrical resistivity 500 nΩm or less and the work function of the alloy higher than 5.0 eV, it is preferable to contain at least one selected from Be, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Rh, Pd, Ag, In, Sn, Sb, Hf, Ta, Ir, Pt, and Bi. More preferably, for the purpose of making the electrical resistivity 100 nΩm or less and the work function of the alloy higher than 5.0 eV, it is preferable to contain at least one selected from Be, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Rh, Pd, Ag, In, Sn, Sb, Ta, Ir, and Pt. For the purpose of making the electrical resistivity 500 nΩm or less and the work function of the alloy between 4.5 eV and 5.0 eV, it is preferable to contain at least one selected from Li, Be, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Ag, In, Sn, Sb, Ba, La, Hf, Ta, Ir, and Bi. More preferably, for the purpose of making the electrical resistivity 100 nΩm or less and the work function of the alloy between 4.5 eV and 5.0 eV, it is preferable to contain at least one selected from Li, Be, Al, V, Cr, Mn, Fe, Ni, Cu, Zn, Y, Nb, Mo, Rh, Ag, In, and Ba. Similarly, for the purpose of making the electrical resistivity 500 nΩm or less and the work function of the alloy between 4.0 eV and 4.5 eV, it is preferable to contain at least one selected from Li, Ti, Y, Zr, Ba, La, Hf, and Ta. More preferably, for the purpose of making the electrical resistivity 100 nΩm or less and the work function of the alloy between 4.0 eV and 4.5 eV, it is preferable to contain Li and Ba. Similarly, for the purpose of having an electrical resistivity of 500 nΩm or less and a work function of the alloy lower than 4.0 eV, it is preferable to include at least one selected from Li, Y, Zr, Ba, La, and Hf, and more preferably, for the purpose of having an electrical resistivity of 100 nΩm or less and a work function of the alloy lower than 4.0 eV, it is preferable to include at least one selected from Li and Ba.

[0022] In one embodiment, the electrical resistivity of the alloy material is 500 nΩm or less, preferably 400 nΩm or less, more preferably 300 nΩm or less, even more preferably 200 nΩm or less, and particularly preferably 100 nΩm or less.

[0023] Furthermore, the composition of alloy materials can be optimized not only for electrical resistivity and work function, but also to satisfy purposes such as controlling the thickness of the tunnel barrier by forming a surface oxide film, optimizing thermal diffusion from the light-receiving portion to the electrode material, and controlling the temperature dependence of resistivity.

[0024] The size and thickness of the contact electrodes are not particularly limited, but the thickness is preferably 10 nm to 1 mm, and more preferably 50 nm to 1 μm.

[0025] The two contact electrodes are spaced apart from each other, with a preferred distance of 1 μm to 500 μm, and more preferably 5 to 200 μm for miniaturization. A distance of 5 μm or more suppresses the degradation of TCR characteristics, even when, for example, a small amount of metallic carbon nanotubes are included. A distance of 500 μm or less is advantageous for application as a two-dimensional array image sensor.

[0026] The method for manufacturing the contact electrodes is not particularly limited, but they may be formed by simultaneous deposition, simultaneous sputtering, printing, etc., or a pre-formed alloy film may be used. The contact electrodes may be formed after forming a bolometer film on the substrate as shown in Figure 1, or the bolometer film may be formed after forming the contact electrodes on the substrate.

[0027] (Bolometer film) In the bolometer-type infrared detector of this embodiment, a carbon nanotube film containing semiconductor carbon nanotubes is used as the bolometer film.

[0028] A carbon nanotube (CNT) film used as a bolometer film is a thin film composed of multiple carbon nanotubes that form a conductive path electrically connecting two contact electrodes. The carbon nanotubes preferably have a network structure, and it is preferable that they form a three-dimensional network structure that is less prone to aggregation and provides a uniform conductive path. Furthermore, in a network of carbon nanotubes, the carbon nanotubes may or may not be oriented, but it is preferable that they be oriented to some extent.

[0029] Carbon nanotubes can be single-walled, double-walled, or multi-walled. However, when separating semiconducting carbon nanotubes, single-walled or multi-walled (e.g., two or three layers) carbon nanotubes are preferred, and single-walled carbon nanotubes are more preferred. The carbon nanotubes preferably contain 80% by mass or more of single-walled carbon nanotubes, and more preferably 90% by mass or more (including 100% by mass).

[0030] The diameter of carbon nanotubes is preferably between 0.6 and 1.5 nm, more preferably between 0.6 nm and 1.2 nm, and even more preferably between 0.7 and 1.1 nm, from the viewpoint of increasing the band gap and improving the TCR. In one embodiment, a diameter of 1 nm or less may be particularly preferable. If the diameter is 0.6 nm or greater, the production of carbon nanotubes is easier. If the diameter is 1.5 nm or less, it is easier to maintain the band gap within an appropriate range, and a high TCR can be obtained.

[0031] In this specification, the diameter of a carbon nanotube means that when a carbon nanotube film is observed using an atomic force microscope (AFM) and the diameter is measured at approximately 100 locations, 60% or more, preferably 70% or more, sometimes more preferably 80% or more, and more preferably 100% are within the range of 0.6 to 1.5 nm. Preferably, 60% or more, preferably 70% or more, sometimes more preferably 80% or more, and more preferably 100% are within the range of 0.6 to 1.2 nm, and even more preferably within the range of 0.7 to 1.1 nm. In one embodiment, 60% or more, preferably 70% or more, sometimes more preferably 80% or more, and more preferably 100% are within the range of 0.6 to 1 nm.

[0032] Furthermore, a carbon nanotube length between 100 nm and 5 μm is more preferable because it disperses easily and has excellent coating properties. From the viewpoint of the conductivity of the carbon nanotube, a length of 100 nm or more is also preferable. Moreover, if the length is 5 μm or less, aggregation during film formation is easily suppressed. The carbon nanotube length is more preferably 500 nm to 3 μm, and even more preferably 700 nm to 1.5 μm.

[0033] In this specification, the length of carbon nanotubes is measured by observing and counting at least 100 nanotubes using an atomic force microscope (AFM) to determine the distribution of carbon nanotube lengths, where 60% or more, preferably 70% or more, sometimes more preferably 80% or more, and more preferably 100% are in the range of 100 nm to 5 μm. Preferably, 60% or more, preferably 70% or more, sometimes more preferably 80% or more, and more preferably 100% are in the range of 500 nm to 3 μm. More preferably, 60% or more, preferably 70% or more, sometimes more preferably 80% or more, and more preferably 100% are in the range of 700 nm to 1.5 μm.

[0034] When the diameter and length of the carbon nanotubes are within the above range, the effect of semiconductivity becomes greater, and a large current value can be obtained, making it easier to obtain a high TCR value when used as a bolometer film.

[0035] For the bolometer film, it is preferable to use semiconducting carbon nanotubes with a large band gap and carrier mobility. The content of semiconducting carbon nanotubes, preferably semiconducting single-walled carbon nanotubes, in the carbon nanotubes is generally 67% by mass or more, preferably 70% by mass or more, more preferably 80% by mass or more, particularly preferably 90% by mass or more, more preferably 95% by mass or more, and even more preferably 99% by mass or more (including 100% by mass).

[0036] The thickness of the bolometer film is not particularly limited, but is, for example, 1 nm or more, for example, several nm to 100 μm, preferably 10 nm to 10 μm, and more preferably 50 nm to 1 μm. In one embodiment, it is preferably in the range of 20 nm to 500 nm, and more preferably 50 nm to 200 nm. A good light absorption rate can be obtained when the thickness of the bolometer film is 1 nm or more. Furthermore, if the thickness of the bolometer film is 10 nm or more, preferably 50 nm or more, a sufficient light absorption rate can be obtained without providing a light-reflecting layer or a light-absorbing layer, thus simplifying the device structure. Furthermore, a thickness of 1 μm or less, preferably 500 nm or less, of the bolometer film is preferable from the viewpoint of simplifying the manufacturing method. Also, if the bolometer film is too thick, the contact electrode formed from above by vapor deposition or the like may not make sufficient contact with the carbon nanotubes below the bolometer film, which may result in a higher effective resistance value. However, within the above range, the increase in resistance value can be suppressed. Furthermore, if the thickness of the bolometer film is within the range of 10 nm to 1 μm as described above, it is preferable because printing technology can be suitably applied as a method for manufacturing the bolometer film. Furthermore, if a light-reflecting layer or a light-absorbing layer is provided, the thickness of the bolometer film may be made thinner than the above range to further simplify the manufacturing process and improve the resistance value.

[0037] The thickness of the bolometer film can be determined as the average of the thicknesses measured at any 10 points on the bolometer film.

[0038] Furthermore, the density of the bolometer film is, for example, 0.3 g / cm³. 3 Preferably 0.8 g / cm³ 3 More preferably 1.1 g / cm³ 3 That concludes the explanation. There is no particular upper limit, but the upper limit of the true density of the carbon nanotubes used (for example, approximately 1.4 g / cm³) is a limiting factor. 3 ) can be done as follows. The density of the bolometer film is 0.3 g / cm³. 3 With these conditions met, a good light absorption rate can be obtained. Furthermore, the density of the bolometer film is 0.5 g / cm³. 3 The above is preferable because it allows for sufficient light absorption without the need for light-reflecting or light-absorbing layers, and simplifies the device structure. Furthermore, if a light-reflecting layer or a light-absorbing layer is provided, a density lower than the above may be appropriately selected as the density of the bolometer film.

[0039] The density of the bolometer film can be calculated from its weight, area, and the thickness determined above.

[0040] Furthermore, in addition to the components mentioned above, other materials such as negative thermal expansion materials, ionic conductive agents (surfactants, ammonium salts, inorganic salts), resins, and organic binders may be used in the bolometer film as appropriate.

[0041] The carbon nanotube content in the bolometer film can be appropriately selected, but preferably, 0.1% by mass or more is effective based on the total mass of the bolometer film, more preferably 1% by mass or more, for example, 30% by mass, and even more preferably 50% by mass or more, and in some cases 60% by mass or more is preferable.

[0042] Hereinafter, an example of a method for manufacturing a carbon nanotube film will be described in detail.

[0043] The carbon nanotubes may be those obtained by removing impurities such as surface functional groups, amorphous carbon, and catalysts by performing heat treatment in an inert atmosphere under vacuum. The heat treatment temperature can be appropriately selected, but is preferably 800 - 2000 °C, and more preferably 800 - 1200 °C.

[0044] The nonionic surfactant can be appropriately selected, but it is preferable to use one or a combination of plural nonionic surfactants composed of a hydrophilic site that does not ionize and a hydrophobic site such as an alkyl chain, such as a nonionic surfactant having a polyethylene glycol structure typified by polyoxyethylene alkyl ether or an alkyl glucoside-based nonionic surfactant. As such a nonionic surfactant, polyoxyethylene alkyl ether represented by the formula (1) is preferably used. Also, the alkyl moiety may contain one or more unsaturated bonds.

[0045] C n H 2n+1 (OCH2CH2) m OH (1) (In the formula, n is preferably 12 - 18, m is 10 - 100, preferably 20 - 100)

[0046] In particular, nonionic surfactants defined as polyoxyethylene(n) alkyl ethers (n is between 20 and 100, alkyl chain length is between C12 and C18), such as polyoxyethylene(23) lauryl ether, polyoxyethylene(20) cetyl ether, polyoxyethylene(20) stearyl ether, polyoxyethylene(10) oleyl ether, polyoxyethylene(10) cetyl ether, polyoxyethylene(10) stearyl ether, polyoxyethylene(20) oleyl ether, and polyoxyethylene(100) stearyl ether, are more preferred. Also, N,N-bis[3-(D-gluconamido)propyl]deoxycholamide, n-dodecyl β-D-maltoside, octyl β-D-glucopyranoside, and digitonin can be used.

[0047] As a nonionic surfactant, polyoxyethylene sorbitan monostearate (molecular formula: C 64 H 126 O 26 Product name: Tween 60, manufactured by Sigma-Aldrich, etc.), polyoxyethylene sorbitan trioleate (molecular formula: C 24 H 44 O6, trade name: Tween 85, manufactured by Sigma-Aldrich, etc.), octylphenol ethoxylate (molecular formula: C 14 H 22 O(C2H4O) n n=1~10, product name: Triton X-100, manufactured by Sigma-Aldrich, etc.), polyoxyethylene (40) isooctylphenyl ether (molecular formula: C8H 17 C6H 40 (CH2CH 20 ) 40 H, product name: Triton X-405, manufactured by Sigma-Aldrich, etc.), poloxamer (molecular formula: C5H 10 O2 (product name: Pluronic, manufactured by Sigma-Aldrich, etc.), polyvinylpyrrolidone (molecular formula: (C6H9NO) n You can also use (e.g., n=5~100, manufactured by Sigma-Aldrich, etc.).

[0048] The method for obtaining a carbon nanotube dispersion solution is not particularly limited, and conventionally known methods can be applied. For example, a solution containing carbon nanotubes can be prepared by mixing a carbon nanotube mixture, a dispersion medium, and a nonionic surfactant, and the carbon nanotubes can be dispersed by sonication of this solution to prepare a carbon nanotube dispersion (micelle dispersion solution). The dispersion medium is not particularly limited as long as it is a solvent that can disperse and suspend the carbon nanotubes during the separation process, and can be used for example, water, heavy water, organic solvents, ionic liquids, or mixtures thereof, but water and heavy water are preferred. In addition to or instead of the sonication, a carbon nanotube dispersion method using mechanical shear force may be used. Mechanical shearing may be performed in the gas phase. In the micelle dispersion aqueous solution of carbon nanotubes and a nonionic surfactant, it is preferable that the carbon nanotubes are in an isolated state. Therefore, if necessary, bundles, amorphous carbon, impurity catalysts, etc. may be removed by ultracentrifugation. During the dispersion process, the carbon nanotubes can be cut, and their length can be controlled by changing the grinding conditions of the carbon nanotubes, ultrasonic output, ultrasonic treatment time, etc. For example, untreated carbon nanotubes can be crushed with tweezers, a ball mill, etc., to control the aggregate size. After these treatments, the length can be controlled to 100 nm to 5 μm by using an ultrasonic homogenizer with an output of 40 to 600 W, sometimes 100 to 550 W, at 20 to 100 KHz, and a processing time of 1 to 5 hours, preferably up to 3 hours. If the processing time is shorter than 1 hour, under certain conditions, the nanotubes may not disperse at all and may remain almost the same length as before. Furthermore, from the viewpoint of shortening the dispersion processing time and reducing costs, 3 hours or less is preferable. This embodiment also has the advantage that the slicing can be easily adjusted by using a nonionic surfactant. It also has the advantage of not containing ionic surfactants, which are difficult to remove.

[0049] Dispersion and scission of carbon nanotubes generate surface functional groups on the surface or edges of the carbon nanotubes. The functional groups generated include carboxyl groups, carbonyl groups, and hydroxyl groups. In liquid-phase processing, carboxyl groups and hydroxyl groups are generated, while in gas-phase processing, carbonyl groups are generated.

[0050] Furthermore, the concentration of the surfactant in the liquid containing heavy water or water and a nonionic surfactant is preferably ~10% by mass, and more preferably ~3% by mass. A concentration below the critical micelle concentration is undesirable because dispersion is not possible. Also, if it is 10% by mass or less, carbon nanotubes of sufficient density can be coated after separation while reducing the amount of surfactant. In this specification, critical micelle concentration (CMC) refers to the concentration at which the inflection point occurs when the surface tension is measured by changing the concentration of the surfactant aqueous solution using a surface tension meter such as a Wilhelmy surface tension meter at a constant temperature. In this specification, "critical micelle concentration" is the value at atmospheric pressure and 25°C.

[0051] The concentration of carbon nanotubes in the above cutting and dispersion process (weight of carbon nanotubes / (total weight of carbon nanotubes, dispersion medium and surfactant) × 100) is not particularly limited, but can be, for example, 0.0003 to 10% by mass, preferably 0.001 to 3% by mass, and more preferably 0.003 to 0.3% by mass.

[0052] The dispersion obtained through the above-described cutting and dispersion process may be used directly in the separation process described later, or it may be subjected to processes such as concentration and dilution before the separation process.

[0053] Carbon nanotubes can be separated, for example, by electric field-induced layer formation (ELF method: see, for example, K. Ihara et al. J.Phys.Chem.C.2011, 115, 22827~22832, Japanese Patent No. 5717233; these documents are incorporated herein by reference). An example of a separation method using the ELF method is described below. Carbon nanotubes, preferably single-walled carbon nanotubes, are dispersed in a nonionic surfactant, and the dispersion is placed in a vertical separation device. By applying a voltage to electrodes positioned above and below, the nanotubes are separated by carrier-free electrophoresis. The separation mechanism can be estimated as follows: When carbon nanotubes are dispersed in a nonionic surfactant, the micelles of semiconductor-type carbon nanotubes have a negative zeta potential, while the micelles of metallic-type carbon nanotubes have a zeta potential with the opposite sign (positive) (recently, it has also been thought that they have a slightly negative zeta potential or are hardly charged at all). Therefore, when an electric field is applied to a carbon nanotube dispersion, conductive carbon nanotube micelles electrophoretically move toward the anode (+) and metallic carbon nanotube micelles electrophoretically move toward the cathode (-) due to differences in zeta potential, etc. Ultimately, a layer concentrated with semiconductor carbon nanotubes is formed near the anode, and a layer concentrated with metallic carbon nanotubes is formed near the cathode in the separation tank. The separation voltage can be appropriately set considering the composition of the dispersion medium and the charge amount of the carbon nanotubes, but 1V to 200V is preferable, and 10V to 200V is more preferable. From the viewpoint of shortening the separation process time, 100V or higher is preferable. Also, from the viewpoint of suppressing the generation of bubbles during separation and maintaining separation efficiency, 200V or lower is preferable. Purity can be improved by repeating the separation. The dispersion after separation may be reset to its initial concentration and the same separation operation may be performed. This will further increase the purity.

[0054] The above-described carbon nanotube dispersion, cleavage, and separation steps allow for the production of a dispersion containing concentrated semiconductor carbon nanotubes having a desired diameter and length. In this specification, the carbon nanotube dispersion containing concentrated semiconductor carbon nanotubes may be referred to as a "semiconductor carbon nanotube dispersion." The semiconductor carbon nanotube dispersion obtained by the separation step generally contains 67% by mass or more, preferably 70% by mass or more, more preferably 80% by mass or more, particularly preferably 90% by mass or more, more preferably 95% by mass or more, and even more preferably 99% by mass or more (the upper limit may be 100% by mass) of semiconductor carbon nanotubes in the total amount of carbon nanotubes. The separation tendency of metallic and semiconductor carbon nanotubes can be analyzed by micro-Raman spectroscopy and ultraviolet-visible near-infrared spectrophotometric analysis.

[0055] After the carbon nanotube dispersion and cleavage steps described above, and before the separation steps, centrifugation may be performed to remove bundles, amorphous carbon, metal impurities, etc., from the carbon nanotube dispersion. The centrifugal acceleration can be adjusted as appropriate, but 10,000 × g to 500,000 × g is preferred, 50,000 × g to 300,000 × g is more preferred, and in some cases 100,000 × g to 300,000 × g may be used. The centrifugation time is preferably 0.5 hours to 12 hours, and more preferably 1 to 3 hours. The centrifugation temperature can be adjusted as appropriate, but 4°C to room temperature is preferred, and more preferably 10°C to room temperature.

[0056] The concentration of the surfactant in the carbon nanotube dispersion after separation can be controlled as appropriate. The concentration of the surfactant in the carbon nanotube dispersion is preferably around 5% by mass, the critical micelle concentration, more preferably 0.001% to 3% by mass, and particularly preferably 0.01% to 1% by mass to suppress re-aggregation after coating.

[0057] A bolometer film can be formed by applying the semiconductor carbon nanotube dispersion obtained through the above process onto a predetermined substrate (such as a substrate or an insulating layer described later), drying it, and optionally performing heat treatment.

[0058] The method for applying a semiconductor carbon nanotube dispersion to a predetermined substrate is not particularly limited and includes methods such as dropping, spin coating, printing, inkjet printing, spray coating, and dip coating. From the viewpoint of reducing manufacturing costs, printing is preferred. Printing methods include coating (dispenser, inkjet, etc.) and transfer (microcontact printing, gravure printing, etc.).

[0059] A dispersion of semiconductor-type carbon nanotubes coated on a predetermined substrate can be heat-treated to remove surfactants and solvents. The heat treatment temperature can be appropriately set above the decomposition temperature of the surfactant, but 150 to 500°C is preferred, and 200 to 500°C, for example 200 to 400°C, is more preferred. A temperature of 200°C or higher is more preferable because it makes it easier to suppress the residue of surfactant decomposition products. Furthermore, a temperature of 500°C or lower, for example 400°C or lower, is preferable because it can suppress the deterioration of the substrate and other components. In addition, it can suppress the decomposition, size change, and detachment of functional groups of carbon nanotubes.

[0060] (Materials with negative thermal expansion) In one embodiment, the bolometer film may include a negative thermal expansion material in addition to carbon nanotubes. The bolometer film according to this embodiment is a carbon nanotube composite material in which a negative thermal expansion material is dispersed within a carbon nanotube aggregate having a three-dimensional network structure formed by the entanglement and aggregation of dispersed carbon nanotubes. In such a three-dimensional conductive network of carbon nanotubes, not all are connected and contribute to conductivity within the bolometer material; some carbon nanotubes do not contribute to the conductive mechanism. These carbon nanotubes construct new conductive paths due to the effect of volume reduction of the negative thermal expansion material as the temperature rises. Alternatively, the effect of volume reduction increases the contact area between carbon nanotubes, and further increases the number of conductive paths. As a result, the increase in current with increasing temperature becomes greater, and the TCR value improves. In other words, the negative thermal expansion material mixed with semiconductor-type carbon nanotubes contracts as the temperature rises, so additional networks are generated between carbon nanotubes that were previously separated, resulting in more conductive paths and more current flow. Furthermore, in one embodiment, by using a negative thermal expansion material with higher resistance than semiconductor-type carbon nanotubes, conductive paths of semiconductor-type carbon nanotubes can be formed more efficiently.

[0061] In this specification, a negative thermal expansion material means a material having a negative expansion coefficient that contracts as the temperature rises. As a negative thermal expansion material, for example, in any temperature range from -100 to +200°C, for example, the range from -100 to +100°C, preferably the operating temperature range of the bolometer, for example, at least -50 to 100°C, the linear thermal expansion coefficient ΔL / L ((length after expansion - length before expansion) / length before expansion) per 1K temperature difference is preferably -1 × 10⁻⁶ -6 / K~-1×10 -3 / K, comfortable-1×10 -5 / K~-1×10 -3 Examples of materials with a K rating include / K. The coefficient of thermal expansion can be measured in accordance with, for example, JIS Z 2285 (Method for measuring the linear expansion coefficient of metallic materials) or JIS R 1618 (Method for measuring thermal expansion of fine ceramics by thermomechanical analysis), etc.

[0062] In one embodiment, the negative thermal expansion material is preferably a material that exhibits sufficient negative thermal expansion in the operating environment of the bolometer. The operating temperature of the bolometer is, for example, -350°C to 100°C, preferably -40°C to 80°C, and more preferably 20°C to 30°C, for example 21°C to 30°C. Furthermore, regarding the humidity of the bolometer's operating environment, for example, when used in a structure where the bolometer is open to the atmosphere, ambient humidity is acceptable, and for example, 75% RH or less is preferred. When used in a structure where it is vacuum-packed or where an inert gas is concentrated inside the package, for example, 5% RH or less is preferred, but depending on the degree of vacuum, it may be outside the above range. However, from the viewpoint of long-term stability of the device, lower humidity is preferable, so in all cases there is no particular lower limit, and it is 0% RH or higher, for example, greater than 0% RH.

[0063] Furthermore, the resistivity of the negative thermal expansion material is not particularly limited, but is 10 in any temperature range of -100 to +100°C, preferably at the operating temperature of the bolometer, for example, room temperature (approximately 23°C). -1 Ωcm~, for example 1Ωcm~10 8 Ωcm, preferably 10Ωcm~10 8 Ωcm, more preferably 10 2 Ωcm~10 7 It can be expressed in Ωcm. Resistivity can be measured according to standard methods such as JIS K 7194 and JIS K 6911.

[0064] In this specification, negative thermal expansion materials include, but are not limited to, oxides, nitrides, sulfides, or multi-element compounds containing one or more of the following elements: Li, Al, Fe, Ni, Co, Mn, Bi, La, Cu, Sn, Zn, V, Zr, Pb, Sm, Y, W, Si, P, Ru, Ti, Ge, Ca, Ga, Cr, and Cd. A mixture of two or more compounds may also be used. Examples of negative thermal expansion materials include, but are not limited to, vanadium oxide, β-eucryptite, bismuth nickel oxide, zirconium tungstate, ruthenium oxide, manganese nitride, lead titanate, samarium monosulfide, etc. (including those in which elements of these compounds are replaced with one or more of the above elements). For example, LiAlSiO4, ZrW2O8, Zr2WO4(PO4)2, BiNi 0.85 Fe 0.15 O3, Bi 0.95 La 0.05 NiO3, Pb 0.76 La 0.04 Bi 0.20 VO3, Sm 0.78 Y 0.22 S, Cu 1.8 Zn 0.2 V2O7, Cu2V2O7, 0.4PbTiO3-0.6BiFeO3, MnCo 0.98 Cr 0.02 Ge, Ca2RuO 3.74 Mn3Ga 0.7 Ge 0.3 N 0.88 C 0.12 , Cd(CN)2·xCCl4, LaFe 10.5 Co 1.0 Si 1.5 Ca2RuO4, Mn 3.27 Zn 0.45 Sn 0.28 N, Mn3Ga 0.9 Sn 0.1 N 0.9 Mn3ZnN is suitable.

[0065] In one embodiment, among negative thermal expansion materials, oxides, nitrides, and sulfides are preferred from the viewpoint of ease of synthesis and availability.

[0066] In this specification, the size of the negative thermal expansion material can be selected as appropriate. Preferably, it is 10 nm to 100 μm, more preferably 15 nm to 10 μm, and in some cases, 50 nm to 5 μm is also preferred. Furthermore, the form of the negative thermal expansion material is not particularly limited, but examples include spherical, needle-shaped, rod-shaped, plate-shaped, fibrous, and flaky shapes, and from the viewpoint of film formation, a spherical shape is preferred.

[0067] Furthermore, the content of the negative thermal expansion material in the bolometer film can be appropriately selected, but it is preferably 1 to 99% by mass, more preferably 1 to 70% by mass, based on the total mass of the bolometer film, for example, 1 to 50% by mass, and in some cases 10 to 50% by mass is also preferable, and in some cases 40% by mass or less is preferable.

[0068] Furthermore, the bolometer film may contain, in addition to carbon nanotubes and a negative thermal expansion material as an optional component, a binder and, if desired, other components. However, the total mass of the carbon nanotubes and the negative thermal expansion material is preferably 70% by mass or more, more preferably 90% by mass or more, and even more preferably 95% by mass or more, based on the mass of the bolometer film.

[0069] A bolometer film containing carbon nanotubes and a negative thermal expansion material can be manufactured in the above-mentioned method for manufacturing a bolometer film using a carbon nanotube dispersion, by using a dispersion to which a negative thermal expansion material and, if necessary, a binder have been added to the carbon nanotube dispersion.

[0070] (substrate) The substrate may be either a flexible substrate or a rigid substrate, and can be selected as appropriate, but at least the element formation surface is preferably insulating and semiconducting. For example, inorganic materials such as Si, SiO2 coated Si, SiO2, SiN, and glass, and organic materials such as polymers, resins, and plastics, such as parylene, polyimide, polyethylene, polypropylene, polystyrene, polyvinyl chloride, polyethylene terephthalate, acrylonitrile styrene resin, acrylonitrile butadiene styrene resin, fluororesin, methacrylic resin, and polycarbonate can be used, but are not limited to these.

[0071] (Manufacturing method for bolometer-type infrared detectors) The bolometer-type infrared detector of this embodiment can be manufactured, for example, as follows: A dispersion containing semiconductor carbon nanotubes is applied to a substrate, dried, and heat-treated. These operations form a bolometer film layer on the substrate. Subsequently, two contact electrodes (first and second electrodes) are fabricated on top of the bolometer film layer at a distance of 50 μm by vapor deposition, sputtering, or coating.

[0072] The bolometer-type infrared detector of this embodiment can also be manufactured as follows: A silicon film coated with SiO2 is used as the substrate, and these are sequentially washed with acetone, isopropyl alcohol, and water, and then organic matter on the surface is removed by oxygen plasma treatment. Next, the substrate is immersed in an aqueous solution of 3-aminopropyltriethoxysilane (APTES) and dried. A dispersion containing semiconductor-type carbon nanotubes dispersed in a polyoxyethylene alkyl ether solution such as polyoxyethylene (100) stearyl ether or polyoxyethylene (23) lauryl ether, which is a nonionic surfactant, is prepared and applied to the substrate and dried. The nonionic surfactant is removed by firing at 200°C or higher in the air. A bolometer film layer is formed on the substrate by these operations. Then, two contact electrodes (first and second electrodes) are prepared at a distance of 50 μm from the bolometer film layer by vapor deposition, sputtering, or coating. An acrylic resin (PMMA) solution is applied to the region between the electrodes on the formed bolometer film layer to form a PMMA protective layer. Next, the entire substrate is treated with oxygen plasma to remove excess carbon nanotubes and other materials in areas other than the bolometer film layer. Excess solvents and impurities are removed by heating to over 200°C in air.

[0073] The resulting bolometer-type infrared detector shown in Figure 1 detects temperature by utilizing the temperature dependence of electrical resistance due to light irradiation. Therefore, it can be used similarly in other frequency ranges as well, if the temperature changes due to light irradiation, and can, for example, detect temperatures in the terahertz range. Furthermore, the detection of changes in electrical resistance due to temperature changes can be achieved not only with the structure shown in Figure 1, but also by amplifying the resistance change by adding a gate electrode to create a field-effect transistor.

[0074] The basic configuration of the bolometer-type infrared detector of this embodiment has been shown above. However, the bolometer-type infrared detector of this embodiment can be fitted with any element structure and array structure that can be used in an infrared detector without any particular limitations. Examples of suitable element structures and array structures are described below, but the bolometer-type infrared detector of this embodiment is not limited to these.

[0075] [1] MEMS-type device structure Figures 4 and 5 are longitudinal cross-sectional views of the elements of the bolometer-type infrared detector of this embodiment. In this structure, an infrared detection unit (light receiving unit) 110 is isolated from the substrate (silicon substrate, etc.) 101, which has a readout circuit 113 formed on it, by a gap 102 between the substrate 101 and the substrate 101, supported by support legs 106. When infrared rays 114 are irradiated, the bolometer film 104 of the infrared detection unit 110 is heated. The temperature change at this time is detected as a change in resistance. In this embodiment, by using an alloy made of two or more metals for at least one of the contact electrodes 103 connected to the bolometer film, a high TCR can be achieved, and thus the detection sensitivity can be increased. In this embodiment, the bolometer-type infrared detector may also be provided with a light-reflecting layer 109 to increase the absorption rate of infrared light, as shown in Figure 4. This layer reflects the infrared light 115 that is not completely absorbed by the bolometer film 104 and is transmitted through, and then re-incidentated to the bolometer film. Alternatively, as shown in Figure 4, an infrared absorption layer 107 may be provided separately directly above the bolometer film, or an infrared absorption structure 107 (not shown) called an overhang may be provided to efficiently absorb the infrared light incident on the pixels.

[0076] [1-1] Components of a bolometer element The following describes in detail each component of the MEMS-type element in this embodiment.

[0077] The substrate 101, contact electrode 103, and bolometer film 104 can be those described above for the substrate 1, bolometer film 3, and contact electrodes 2 and 4. Other components are described below.

[0078] (gap) In the bolometer-type infrared detector of this embodiment, a gap 102 is provided between the infrared detection unit 110, which is equipped with the bolometer film 104, and the substrate 101. In a bolometer equipped with a light-reflecting layer 109 as shown in Figure 4, it is preferable to determine the height d of the gap by considering the wavelength of the infrared light to be absorbed. In a bolometer without a light-reflecting layer as shown in Figure 5, the height d of the gap may be set to a desired value without considering the wavelength of the infrared light to be absorbed. From the viewpoint of ease of manufacture, it is preferable to set the height d of the gap to 0.5 μm or more. The height d of the gap represents the distance from the upper surface of the substrate 101 (or the upper surface of any insulating protective film, etc., present on the substrate) to the lower surface of the infrared detection unit 110. Furthermore, by vacuum packaging the entire element and maintaining a vacuum in the gap 102, the heat insulation between the infrared detection unit and the substrate can be improved.

[0079] (Infrared absorbing structure) In the bolometer-type infrared detector of this embodiment, an infrared absorption structure can be provided. For example, to efficiently absorb incident infrared radiation, an overhang-shaped infrared absorption structure 107 may be provided to further improve the fill factor. Such a structure may be made of SiN, for example, but is not limited to this, and any structure used in the art can be applied without particular restriction. Furthermore, as shown in Figure 4, an infrared absorption layer 107 may be provided above the bolometer film 104, that is, on the side where infrared light is incident. The infrared absorption layer may be provided directly on the bolometer film 104, or on top of the protective layer described later. The thickness of the infrared absorption layer can be set appropriately depending on the material, but for example, it can be 50 nm to 1 μm. When the infrared absorption layer 107 is directly provided on the bolometer film 104, examples include, but are not limited to, a polyimide coating film. The infrared absorption layer 107 provided on the protective layer is not limited to, but examples include a titanium nitride thin film.

[0080] (light reflective layer) In the bolometer-type infrared detector of this embodiment, as shown in Figure 4, a light-reflecting layer 109 may be provided between the bolometer film 104 and the substrate 101, for example, on the substrate 101. The light-reflecting layer 109 can be any material used as a light-reflecting layer in a bolometer, and generally, metals such as gold, silver, and aluminum can be used.

[0081] When a light-reflecting layer 109 is provided as shown in Figure 4, it is preferable to set the distance d between the light-reflecting layer 109 and the bolometer film 104, i.e., the height of the gap 102, to d = λ / 4, taking into consideration the wavelength λ of the infrared light to be absorbed.

[0082] Furthermore, the bolometer film containing semiconductor carbon nanotubes according to this embodiment has a higher infrared absorption rate compared to conventional bolometer films. Therefore, it is not always necessary to provide a light-reflecting layer or an infrared-absorbing layer, and as shown in Figure 5, one or both of these components can be omitted. This allows for a simpler device structure and reduces the cost of the manufacturing process.

[0083] (protective layer) In the bolometer-type infrared detector of this embodiment, as shown in Figures 4 and 5, it is preferable that a protective layer 108 exists on the bolometer film 104 and above and below the wiring 105. The protective layer can function as an insulating protective layer, and the protective layer located above the bolometer film may have effects such as suppressing doping of carbon nanotubes by adsorption of oxygen, etc., or increasing the infrared absorption rate by absorbing infrared rays not only in the bolometer film but also in the protective layer. The protective layer 108 can be any material used as a protective layer in a bolometer, and a material with high transparency in the infrared wavelength range to be detected is preferred. Examples include silicon nitride film, silicon oxide film, resins used in the heat insulating layer described later, such as parylene, as well as acrylic resins such as PMMA and PMMA anisole, epoxy resins, Teflon (registered trademark), etc., but are not limited to these. The thickness of the protective layer can be, for example, 5 nm to 50 nm, depending on the material.

[0084] [1-2] Array structure Although the above embodiment shows a bolometer with one cell (single element), multiple elements can be arranged in an array to form a bolometer array. Figure 6 is a plan view showing a bolometer array in which the sensor cells of Figures 4 and 5 are arranged in an array. A two-dimensional image sensor can be constructed by connecting the contact electrodes 103 of each element with multiple column wirings 112 and contacts 105 for each column, and with multiple row wirings 111 and contacts 105 for each row. In such a structure, an electrical signal is applied to the row wiring 111 and column wiring 112 corresponding to each cell to read out the resistance change of the cell. By sequentially reading out the resistance changes of all cells, an infrared image sensor can be constructed.

[0085] [1-3] Structure and manufacturing method of bolometer element and bolometer array As for the manufacturing method of the bolometer element and bolometer array according to this embodiment, a carbon nanotube film containing semiconductor-type carbon nanotubes is used for the bolometer film, and at least one of the contact electrodes connected to the bolometer film is formed from an alloy of two or more metals, except that a manufacturing process commonly used for manufacturing bolometers can be used without limitation.

[0086] The silicon MEMS (Micro Electro Mechanical Systems) process is typically used to fabricate devices like those shown in Figures 4 and 5. In the MEMS process, first, an interlayer insulating film is formed by CVD on a semiconductor substrate 101 on which a readout circuit 113 composed of CMOS (Complementary Metal Oxide Semiconductor) transistors is created. A metallic light-reflecting layer 109, an interlayer insulating film, and a sacrificial layer are then formed on top of this. Next, a protective insulating film of silicon nitride is formed by CVD, and a contact electrode 103 made of an alloy of two or more metals according to this embodiment is formed on top of it. Then, a bolometer film 104 connected to the contact electrode 103 and a second silicon nitride film 108 are formed. Finally, the sacrificial layer is removed by etching to form a gap 102, obtaining a diaphragm-structured cell. Here, the bolometer film 104 can be formed by printing, as described above, and its thickness and density are, for example, 100 nm thick and 1.1 g / cm³ dense. 3 That is the case.

[0087] In addition to the above components, if an infrared absorbing layer 107 is provided, it may be formed on the bolometer film 104 or silicon nitride film by printing or the like, or a pre-formed infrared absorbing layer may be laminated.

[0088] Furthermore, it is also preferable to apply a transistor array to the bolometer array of this embodiment. Applying a transistor array offers advantages such as enabling high-speed scanning. The form of the transistor array is not particularly limited, and any form used in the art can be applied without particular restriction, such as fabricating the transistor array beneath the light-receiving section.

[0089] [2] Printed element structure Figure 7 is a longitudinal cross-sectional view of the element of the bolometer-type infrared detector of this embodiment. In this structure, a heat insulating layer (parylene layer, etc.) 202 is provided on a substrate (polyimide substrate, etc.) 201, and a bolometer film (carbon nanotube film) 204 is provided on the heat insulating layer 202. In such a bolometer-type infrared detector, the intensity of infrared radiation is detected by reading the change in resistance due to the temperature rise of the bolometer film from the electrodes. In this embodiment, by forming at least one of the contact electrodes 203 connected to the bolometer film 204 from an alloy made of two or more metals, a high TCR can be achieved and the detection sensitivity can be increased.

[0090] In the bolometer-type infrared detector of this embodiment, the bolometer film 204 and the substrate 201 are thermally separated by the insulating layer 202, so heat does not easily escape from the bolometer film 204, improving detection sensitivity. Furthermore, compared to a bolometer with a diaphragm-type structure that has a gap between the substrate 201 and the bolometer film 204, it has the advantage of a simpler element structure and does not require vacuum packaging to create a vacuum in the gap. Furthermore, since these bolometer films 204 and thermal insulation layers 202 can be fabricated using printing technology, there is the advantage of being able to reduce manufacturing costs compared to using MEMS processes.

[0091] [2-1] Components of a bolometer element The components of the bolometer element in this embodiment will be described in detail below.

[0092] The substrate 201, contact electrode 203, and bolometer film 204 can be those described above for substrate 1, bolometer film 3, and contact electrodes 2 and 4. Other components are described below.

[0093] (Insulation layer) The heat insulating layer 202 is a layer that blocks heat transfer from the bolometer film 204 to the substrate 201. In conventional bolometers, a gap is provided as a structure to block heat transfer from the bolometer film to the substrate, and its formation requires a complex manufacturing process as described above. However, the heat insulating layer in this embodiment can be formed by a printing process, eliminating the need for a complex manufacturing process. In addition, conventional bolometers require vacuum packaging of the entire element to maintain a vacuum in the gap, but the bolometer of this embodiment has the advantage of not requiring vacuum packaging.

[0094] It is preferable to use a resin component with low thermal conductivity for the thermal insulation layer. The thermal conductivity of the resin component used for the thermal insulation layer is lower than the thermal conductivity of the substrate 201, for example, in the range of 0.02 to 0.3 (W / mK), preferably 0.05 to 0.15 (W / mK). Examples of such resin components include, but are not limited to, parylene. Parylene is a general term for paraxylylene polymers, and has a structure in which benzene rings are linked via CH2. Examples of parylene include those formed from dimers represented by the following formula:

[0095] [ka] (In the formula, at least one hydrogen atom of at least one benzene ring may be substituted with a halogen atom. Examples of halogens include fluorine (F), chlorine (Cl), bromine (Br), and iodine (I), with chlorine being preferred.) Examples of parylene include parylene N, parylene C, parylene D, and parylene HT, but among them, parylene C (thermal conductivity: 0.084 (W / mK)) is preferred because it has the lowest thermal conductivity.

[0096] The thickness of the insulating layer can be set appropriately considering the thermal conductivity of the components used, but for example, when parylene C is used, a range of 5 μm to 50 μm is preferred, and a range of 10 μm to 20 μm is more preferred. Furthermore, when a light-reflecting layer is provided to improve infrared absorption, it is preferable to set the distance between the bolometer film 204 and the light-reflecting layer to d = λ / 4, taking into consideration the wavelength λ of the infrared radiation to be absorbed, as described above. On the other hand, when the light-reflecting layer is omitted, the thickness of the heat-insulating layer can be freely set within the range in which the desired heat insulation performance can be obtained, without considering the wavelength λ of the infrared radiation to be absorbed. In this case, there is also the advantage that it can be used for detecting electromagnetic waves in a wider wavelength range.

[0097] (Infrared absorbing layer) In the bolometer-type infrared detector of this embodiment, as shown in Figure 7, an infrared absorption layer 209 may be provided above the bolometer film 204, that is, on the side where infrared light is incident. The infrared absorption layer may be provided on the protective layer 208 described later, or it may be provided directly on the bolometer film 204. As shown in Figure 7, when an infrared absorption layer 209 is provided, the infrared absorption layer can be, for example, one of the examples given in the above-described MEMS-type device.

[0098] (light reflective layer) In the bolometer-type infrared detector of this embodiment, as shown in Figure 7, a light-reflecting layer (infrared-reflecting layer) 210 may be provided between the bolometer film 204 and the substrate 201 to absorb infrared light that is incident from above and has passed through the bolometer film without being absorbed. When a light-reflecting layer is provided, it is preferable to set the distance between the light-reflecting layer 210 and the bolometer film 204 to d = λ / 4, taking into consideration the wavelength λ of the infrared light to be absorbed. As the light-reflecting layer 210, for example, one like the one exemplified in the MEMS type device can be used.

[0099] Furthermore, the bolometer film containing semiconductor carbon nanotubes according to this embodiment has a higher infrared absorption rate compared to conventional bolometer films. Therefore, it is not always necessary to provide a light-reflecting layer or an infrared-absorbing layer, and one or both of these components can be omitted. This simplifies the device structure and makes it possible to reduce the cost of the manufacturing process.

[0100] (protective layer) In the bolometer-type infrared detector of this embodiment, it is preferable that a protective layer 208 exists on the bolometer film 204, as shown in Figure 7. As the protective layer 208, for example, those exemplified in the MEMS type device can be used.

[0101] [2-2] Array structure Printed elements can also be arranged in an array-like manner to form a bolometer array, as explained in Figure 6 regarding the MEMS-type element structure.

[0102] [2-3] Method for manufacturing a bolometer The method for manufacturing the bolometer according to this embodiment is not particularly limited, and any method used for manufacturing a bolometer can be appropriately adopted. From the viewpoint of simplifying the manufacturing process and reducing costs, it is preferable to form the heat insulating layer and the bolometer film on a desired substrate using a printing method or the like, but it is not necessarily limited to a printing method.

[0103] (1) Bolometer film A dispersion containing semiconductor-type carbon nanotubes obtained by the above process can be applied to the above-mentioned heat insulating layer and dried to form a bolometer film. Alternatively, a bolometer film formed by applying a dispersion containing carbon nanotubes on a desired substrate may be laminated with the above-mentioned heat insulating layer. The same process and conditions as those used for film formation on the above-mentioned substrate may be applied for film formation.

[0104] (2) Insulation layer The method for manufacturing the thermal insulation layer is not particularly limited as long as it is a method that can produce the thermal insulation layer described above. For example, when a parylene film is used as the thermal insulation layer, the parylene film can be formed by coating a desired area with parylene using a vacuum deposition apparatus. Specifically, when a solid dimer is heated under vacuum, it vaporizes into a dimer gas. This gas decomposes thermally, causing the dimer to cleave and become monomers. In a deposition chamber at room temperature, this monomer gas polymerizes on all surfaces, forming a thin, transparent polymer film. If necessary, pretreatment of the substrate, cleaning of the substrate, and masking of areas that should not be coated may be performed before the vapor deposition process.

[0105] (3) Structure and manufacturing method of bolometer array An example of the structure and manufacturing method of a bolometer array according to this embodiment will be described with reference to the figures, but the structure and manufacturing method of a bolometer array are not limited to these.

[0106] [Example 1] In Figure 8(a), a 1000 Å aluminum film is deposited onto the substrate 201 through a metal mask to form a row of wiring 206. Next, an insulating film 211 is formed by coating polyimide. Row wiring 207 is formed on top of this, similar to the row wiring. A second insulating film 211 is then formed by coating polyimide on top of this. Next, as shown in Figure 8(b), a parylene film is formed as the heat insulating layer 202 by vapor deposition to a thickness of approximately 20 μm, for example. Parylene is normally in a dimer state, but it is heated to approximately 700°C in the vapor deposition apparatus, becoming a monomer, and then becomes a polymer after being deposited on the substrate. Next, as shown in Figure 8(c), the contact holes 205 are opened by lithography and dry etching. Next, as shown in Figure 8(d), contact electrodes 203 according to this embodiment are formed, connected to the row wiring and column wiring via the contact holes 205. The electrodes 203 can be formed by vapor deposition, sputtering, printing, or the like. Alternatively, the contact electrodes 203 may be formed after the bolometer film 204 has been formed. Subsequently, a bolometer film 204 is formed. The bolometer film 204 is preferably formed by a printing method, for example, by applying the carbon nanotube dispersion described above using a dispenser device. Here, the thickness and density of the bolometer film are, for example, 100 nm thick and 1.1 g / cm³ dense. 3 That is the case.

[0107] When a light-reflecting layer is provided, a parylene film is formed as the heat insulating layer 202, then a light-reflecting layer 210 is formed on top of it by vapor deposition of aluminum (1000 Å), and then a second heat insulating layer 202 is formed on top of that by vapor deposition of parylene to a thickness of approximately 2.5 μm (distance d). In addition to the above components, if a protective film 208 is to be provided, for example, a resin solution used for the protective layer can be applied to the formed bolometer film 204 to form the protective layer. After this, the entire substrate may be treated with oxygen plasma to remove excess carbon nanotubes and the like in areas other than the bolometer film 204. In addition to the above components, if an infrared absorbing layer 209 is provided, it may be formed on the bolometer film 204 or protective film 208 by printing or the like, or a pre-formed infrared absorbing layer may be laminated or transferred.

[0108] The following examples show a method for manufacturing a bolometer that does not have a light-reflecting layer, an infrared-absorbing layer, a protective layer, etc., but naturally, these manufacturing methods may further include a step of forming a light-reflecting layer, an infrared-absorbing layer, a protective layer, etc.

[0109] [Example 2] Another example will be explained with reference to Figure 9. First, as shown in Figure 9(a), a heat insulating layer 202 is formed on the substrate 201, and then the first electrode 203-1 and the row wiring 206 are formed on top of it. Next, an insulating film 211 is formed to insulate a portion of the column wiring 206, specifically the portion that will intersect with the row wiring in a later process. One method for forming the insulating film is to apply polyimide using a printing method. Next, as shown in Figure 9(b), the second electrode 203-2 and row wiring 207 are formed in the same manner as the first electrode and row wiring. At least one of the first electrode and the second electrode is a contact electrode made of an alloy of two or more metals according to this embodiment, and can be formed by vapor deposition or sputtering. The column wiring and row wiring may be made of the same material as the first electrode and the second electrode, or they may be made of different materials, but it is more preferable to use materials commonly used for wiring layers in CMOS processes, such as gold, aluminum, titanium, or alloys thereof, for the column wiring and row wiring. If the column wiring and row wiring are made of the same material as the first electrode and the second electrode, they may be formed at the same time as the first electrode and the second electrode. Next, as shown in Figure 9(c), a bolometer film 204 is formed to connect to the first and second electrodes. This method allows for the manufacture of bolometer arrays using printing processes or other methods without contact formation, thereby enabling further cost reduction.

[0110] [Example 3] Another example will be explained with reference to Figure 10. In the bolometer array shown in Figure 10, the bolometer array is formed on a first substrate 212 such as a resin substrate, and a readout circuit is formed on a second substrate 213, which is a semiconductor substrate, using a normal silicon CMOS process (not shown). An insulating layer is formed on the readout circuit, and the first substrate is attached to the second substrate. The bolometer array of this embodiment can be formed by electrically connecting the column terminals 214 and row terminals 215 of the first substrate to the terminals connected to the column selection circuit 216 and row selection circuit 217 in the readout circuit on the second substrate using bonding wires 218 or the like.

[0111] [Example 4] Another example will be explained with reference to Figure 11. In this embodiment, it is also preferable to apply a TFT (thin-film transistor) array to the bolometer array. By applying a TFT array, high-speed scanning becomes possible. The form of the TFT array is not particularly limited, but an example is shown in Figure 11. In the TFT array shown in Figure 11(a), a gate electrode 219 is placed on a substrate 201, and contact electrodes (source electrode 220, drain electrode 222) are formed on the upper layer via an insulating layer. A heat insulating layer 202, a bolometer film 204, and a protective film 208 are formed on the upper layer. The drain electrode 222 is connected to a pixel electrode 203 that is in contact with the bolometer film 204 via a via 223 that penetrates the heat insulating layer 202. The other electrode 203 is connected to a common electrode 224. It is preferable to form at least one of the electrodes 203 that are joined to the bolometer film 204 using the alloy of this embodiment. The two-dimensional arrangement of the pixel circuit of this TFT array is shown in Figure 11(b).

[0112] Some or all of the above embodiments may also be described as follows, but the disclosures of this application are not limited to the following.

[0113] (Note 1) substrate, A bolometer film containing semiconductor-type carbon nanotubes, and Two electrodes are bonded to the bolometer film at a distance from each other. It has at least the following features: A bolometer-type infrared detector, wherein at least one of the two electrodes is formed of an alloy containing at least two metals selected from the group consisting of Li, Be, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, In, Sn, Sb, Ba, La, Hf, Ta, Ir, Pt, Au, and Bi. (Note 2) The bolometer-type infrared detector described in Appendix 1, wherein the two electrodes are formed from the same alloy. (Note 3) The bolometer-type infrared detector described in Appendix 1, wherein the two electrodes are formed of different alloys. (Note 4) At least one of the two electrodes is Alloys of Al with one or more elements selected from Pd, Pt, and Au; one or more elements selected from Fe, Co, Ni, Cu, Mo, Ru, Rh, Pd, Ag, Sb, Ir, Pt, and Au; one or more elements selected from Be, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Ag, In, Sn, Sb, Hf, Ta, and Bi; or one or more elements selected from Li, Y, Zr, Ba, La, Hf, and Ta. • Alloys of Cu with one or more selected from Pd, Pt, and Au; one or more selected from Be, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, Zr, Nb, Mo, Ru, Rh, Pd, Ag, In, Sn, Sb, Hf, Ta, Ir, Pt, Au, and Bi; one or more selected from Li, Al, Mn, Zn, Y, Nb, In, Ba, La, and Ta; or one or more selected from Li and Ba. • Alloys of Ag and one or more selected from Pd, Pt, and Au; one or more selected from Be, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Rh, Pd, In, Sn, Sb, Hf, Ta, Ir, Pt, Au, and Bi; one or more selected from Li, Be, Al, Ti, Mn, Zn, Y, Zr, Ba, La, Hf, and Ta; and one or more selected from Li and Ba. A alloy of Au with one or more elements selected from Be, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Rh, Pd, Ag, In, Sn, Sb, Ta, Ir, and Pt, one or more elements selected from Li, Be, Al, V, Cr, Mn, Fe, Ni, Cu, Zn, Y, Nb, Mo, Rh, Ag, In, and Ba, or one or more elements selected from Li and Ba. A bolometer-type infrared detector, as described in any one of the appendices 1 to 3, formed from an alloy selected from the group consisting of the following. (Note 5) A bolometer-type infrared detector according to any one of the appendices 1 to 4, wherein the bolometer film is composed of a composite material containing carbon nanotubes and a negative thermal expansion material. (Note 6) The bolometer-type infrared detector according to Appendix 5, wherein the negative thermal expansion material is an oxide, nitride, sulfide, or multi-element compound containing one or more elements selected from the group consisting of Li, Al, Fe, Ni, Co, Mn, Bi, La, Cu, Sn, Zn, V, Zr, Pb, Sm, Y, W, Si, P, Ru, Ti, Ge, Ca, Ga, Cr, and Cd. (Note 7) A bolometer-type infrared detector according to any one of the appendices 1 to 6, wherein the bolometer film contains semiconductor-type carbon nanotubes in an amount of 90% by mass or more of the total amount of carbon nanotubes. (Note 8) The process of preparing the circuit board, A process of forming a bolometer film containing semiconductor carbon nanotubes on a substrate, A step of forming two electrodes before or after the step of forming the bolometer film, such that the two electrodes are joined to the bolometer film at a distance from each other, wherein at least one of the two electrodes is formed of an alloy containing at least two metals selected from the group consisting of Li, Be, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Y, Zr, Nb, Mo, Ru, Rh, Pd, Ag, In, Sn, Sb, Ba, La, Hf, Ta, Ir, Pt, Au, and Bi. A method for manufacturing a bolometer-type infrared detector, including the method described above. [Explanation of Symbols]

[0114] 1 circuit board 2 Contact electrodes 3. Bolometer film (carbon nanotube film) 4 Contact electrodes 101 circuit board 102 Gap 103 Electrode 104 Bolometer film 105 Wiring 106 Support legs 107 Infrared absorbing layer / infrared absorbing structure 108 Protective layer (insulating protective layer) 109 Light-reflecting layer (infrared-reflecting layer) 110 Infrared detection unit 111 row wiring 112 column wiring 113 Readout circuit 114 Incident light 115 Light transmitted through the bolometer film 201 circuit board 202 Insulation layer 203 Electrode 204 Bolometer film 205 Contact 206 column wiring 207 row wiring 208 Protective layer 209 Infrared absorption layer 210 Light reflective layer 211 Insulating film 212 First substrate 213 Second board 214 row terminals 215 row terminal 216-row selection circuit 217 Row Selection Circuit 218 Bonding Wire 219 TG 220 source electrodes 221 Semiconductors 222 Drain electrode 223 Beer 224 Common Electrode 225 Source Line 226 Gate Line

Claims

1. substrate, A bolometer film containing semiconductor-type carbon nanotubes, and Two electrodes are bonded to the bolometer film at a distance from each other. It has at least the following features: At least one of the two electrodes is - Alloys of Al with one or more elements selected from Pd, Pt, and Au, one or more elements selected from Fe, Co, Ni, Cu, Mo, Ru, Rh, Pd, Ag, Sb, Ir, Pt, and Au, one or more elements selected from Be, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Ag, In, Sn, Sb, Hf, Ta, and Bi, or one or more elements selected from Li, Y, Zr, Ba, La, Hf, and Ta. - Alloys of Cu with one or more selected from Pd, Pt, and Au, one or more selected from Be, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, Zr, Nb, Mo, Ru, Rh, Pd, Ag, In, Sn, Sb, Hf, Ta, Ir, Pt, Au, and Bi, one or more selected from Li, Al, Mn, Zn, Y, Nb, In, Ba, La, and Ta, or one or more selected from Li and Ba. - Alloys of Ag and one or more selected from Pd, Pt, and Au, one or more selected from Be, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Rh, Pd, In, Sn, Sb, Hf, Ta, Ir, Pt, Au, and Bi, one or more selected from Li, Be, Al, Ti, Mn, Zn, Y, Zr, Ba, La, Hf, and Ta, or one or more selected from Li and Ba, and - Alloys of Au with one or more elements selected from Be, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Rh, Pd, Ag, In, Sn, Sb, Ta, Ir, and Pt, one or more elements selected from Li, Be, Al, V, Cr, Mn, Fe, Ni, Cu, Zn, Y, Nb, Mo, Rh, Ag, In, and Ba, or one or more elements selected from Li and Ba. A bolometer-type infrared detector, formed from an alloy selected from the group consisting of the following.

2. The bolometer-type infrared detector according to claim 1, wherein the two electrodes are formed of the same alloy.

3. The bolometer-type infrared detector according to claim 1, wherein the two electrodes are formed of different alloys.

4. The bolometer-type infrared detector according to any one of claims 1 to 3, wherein the bolometer film is composed of a composite material containing carbon nanotubes and a negative thermal expansion material.

5. The bolometer-type infrared detector according to claim 4, wherein the negative thermal expansion material is an oxide, nitride, sulfide, or multi-element compound containing one or more elements selected from the group consisting of Li, Al, Fe, Ni, Co, Mn, Bi, La, Cu, Sn, Zn, V, Zr, Pb, Sm, Y, W, Si, P, Ru, Ti, Ge, Ca, Ga, Cr, and Cd.

6. The bolometer-type infrared detector according to any one of claims 1 to 3, wherein the bolometer film contains semiconductor-type carbon nanotubes in an amount of 90% by mass or more of the total amount of carbon nanotubes.

7. The process of preparing the circuit board, A process of forming a bolometer film containing semiconductor carbon nanotubes on a substrate, A step of forming two electrodes before or after the step of forming the bolometer film, such that the two electrodes are joined to the bolometer film at intervals, wherein at least one of the two electrodes is - Alloys of Al with one or more elements selected from Pd, Pt, and Au, one or more elements selected from Fe, Co, Ni, Cu, Mo, Ru, Rh, Pd, Ag, Sb, Ir, Pt, and Au, one or more elements selected from Be, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Ag, In, Sn, Sb, Hf, Ta, and Bi, or one or more elements selected from Li, Y, Zr, Ba, La, Hf, and Ta. - Alloys of Cu with one or more selected from Pd, Pt, and Au, one or more selected from Be, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Zn, Zr, Nb, Mo, Ru, Rh, Pd, Ag, In, Sn, Sb, Hf, Ta, Ir, Pt, Au, and Bi, one or more selected from Li, Al, Mn, Zn, Y, Nb, In, Ba, La, and Ta, or one or more selected from Li and Ba. - Alloys of Ag and one or more selected from Pd, Pt, and Au, one or more selected from Be, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Rh, Pd, In, Sn, Sb, Hf, Ta, Ir, Pt, Au, and Bi, one or more selected from Li, Be, Al, Ti, Mn, Zn, Y, Zr, Ba, La, Hf, and Ta, or one or more selected from Li and Ba, and - Alloys of Au with one or more elements selected from Be, Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Zr, Nb, Mo, Ru, Rh, Pd, Ag, In, Sn, Sb, Ta, Ir, and Pt, one or more elements selected from Li, Be, Al, V, Cr, Mn, Fe, Ni, Cu, Zn, Y, Nb, Mo, Rh, Ag, In, and Ba, or one or more elements selected from Li and Ba. Formed from an alloy selected from the group consisting of the process A method for manufacturing a bolometer-type infrared detector, including the method described above.

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