Thermal infrared detector and method for manufacturing same

Abstract

A thermal infrared detector (100) is provided with: an infrared detection unit (12) that is provided on the surface of a substrate (11) and has an element (103) that converts a temperature change caused by the incidence of infrared rays into an electric signal; a peripheral circuit (13) that is provided on the surface of the substrate (11) so as to surround the infrared detection unit (12) and that reads out an electric signal from the element (103); a sealing part (14) provided in the peripheral circuit (13) so as to surround the infrared detection part (12); a sealing window (15) that is provided to the sealing part (14) and forms, together with the substrate (11), the peripheral circuit (13), and the sealing part (14), an internal space in a sealed state in which the infrared detection part (12) is housed; an infrared absorbing film (16) that covers at least the surface of the inside portion of the sealing part (14) among the surfaces of the peripheral circuit (13); and a waste heat wiring (17) that is provided inside the peripheral circuit (13) and thermally connects the substrate (11) and the infrared absorbing film (16).

Description

Technical Field

[0001] The present disclosure relates to a thermal infrared detector and a method for manufacturing the same. Background Art

[0002] Infrared detectors for detecting infrared rays are roughly classified, according to their operating principles, into thermal infrared detectors that utilize temperature changes caused by the absorption of heat energy of infrared rays and quantum infrared detectors that utilize carrier excitation generated by the absorption of infrared rays.

[0003] Quantum infrared detectors operate at low temperatures and require a refrigerator to cool the elements themselves to about -200°C. Therefore, quantum infrared detectors not only have a complex structure but also require maintenance of the refrigerator. As a result, quantum infrared detectors have the disadvantages of high manufacturing costs and difficulty in handling.

[0004] Thermal infrared detectors can operate at room temperature without using a refrigerator. In addition, a thermal infrared detector can simultaneously form an infrared detection unit having a temperature sensor and a signal readout circuit on a semiconductor production line. Therefore, compared with quantum infrared detectors, thermal infrared detectors can be miniaturized and made inexpensive. Therefore, thermal infrared detectors have become mainstream in civil applications such as for safety and in-vehicle use.

[0005] In addition, in thermal infrared detectors, cost reduction of optical systems that tend to become expensive is being promoted. Specifically, the material of the lens is changed from an expensive glass material such as germanium (Ge) used in the past to an inexpensive glass material such as silicon (Si) or chalcogenide glass. In addition, the optical system is simplified by reducing the number of lens elements. Furthermore, by shortening the pixel pitch, reducing the image circle, and reducing the lens diameter, the amount of glass material used is reduced.

[0006] However, there is a trade-off relationship between the above cost reduction methods and the imaging performance of the optical system. Therefore, when the above cost reduction methods are used, an increase in focus shift and an increase in stray light may occur. In particular, if the stray light incident on the peripheral circuit is multiply scattered between the sealing window and the sealing portion and then incident on the infrared detection unit, a problem such as a decrease in the detection accuracy of the temperature change of infrared rays will occur.

[0007] A technique for suppressing stray light is disclosed in Patent Document 1.

[0008] Prior Art Documents

[0009] Patent Documents

[0010] Patent Document 1: Japanese Unexamined Patent Application Publication No. 2010-238726 Summary of the Invention

[0011] Problems to be Solved by the Invention

[0012] The stray light suppression technique disclosed in Patent Document 1 absorbs stray light through a light absorption film. However, this stray light suppression technique has a problem that it cannot appropriately handle the heat of the absorbed stray light.

[0013] The present disclosure has been made to solve the above problems, and an object thereof is to provide a thermal infrared detector capable of discharging the heat of the absorbed stray light to a component having a large heat capacity.

[0014] Means for Solving the Problems

[0015] The thermal infrared detector of the present disclosure includes: an infrared detection unit provided on the surface of a substrate and having an element that converts a temperature change caused by the incidence of infrared rays into an electric signal; a peripheral circuit provided on the surface of the substrate so as to surround the infrared detection unit and reads an electric signal from the element; a sealing unit provided so as to surround the infrared detection unit on the peripheral circuit; a sealing window provided on the sealing unit, and together with the substrate, the peripheral circuit, and the sealing unit, forms an internal space in a sealed state for housing the infrared detection unit; an infrared absorption film covering at least the inner surface of the surface of the peripheral circuit; and a waste heat wiring provided inside the peripheral circuit and thermally connecting the substrate and the infrared absorption film.

[0016] Advantages of the Invention

[0017] According to the present disclosure, the heat of the absorbed stray light can be discharged to a substrate having a large heat capacity. Description of the Drawings

[0018] Figure 1 is a plan view of the thermal infrared detector of Embodiment 1.

[0019] Figure 2 is Figure 1 a sectional view taken along line II-II of

[0020] Figure 3A is a sectional view showing a manufacturing method of the thermal infrared detector.

[0021] Figure 3B is Figure 3A a sectional view showing a manufacturing method of the thermal infrared detector continued from

[0022] Figure 3C is Figure 3B a sectional view showing a manufacturing method of the thermal infrared detector continued from

[0023] Figure 3D isFigure 3C A cross-sectional view showing a method of manufacturing a pyroelectric infrared detector, shown successively.

[0024] Figure 3E It is related to Figure 3D A cross-sectional view showing a method of manufacturing a pyroelectric infrared detector, shown successively.

[0025] Figure 4 A cross-sectional view of the pyroelectric infrared detector of Embodiment 2.

[0026] Figure 5 A cross-sectional view of the pyroelectric infrared detector of Embodiment 3.

[0027] Figure 6 A cross-sectional view of the pyroelectric infrared detector of Embodiment 4.

[0028] Figure 7 A top view of the pyroelectric infrared detector of Embodiment 5.

[0029] Figure 8 It is Figure 7 A cross-sectional view taken along the VIII-VIII direction.

[0030] Figure 9 A cross-sectional view of the pyroelectric infrared detector of Embodiment 6. Detailed implementation mode

[0031] Hereinafter, in order to explain the present disclosure in more detail, the modes for implementing the present disclosure will be described with reference to the drawings.

[0032] Embodiment 1.

[0033] Using Figure 1 , Figure 2 and Figures 3A to 3E The pyroelectric infrared detector 100 of Embodiment 1 will be described.

[0034] First, using Figure 1 and Figure 2 The structure of the pyroelectric infrared detector 100 of Embodiment 1 will be described. Figure 1 A top view of the pyroelectric infrared detector 100 of Embodiment 1. Figure 2 It is Figure 1 A cross-sectional view taken along the I-I direction. Additionally, Figure 1 Shows a top view in a state where the sealing window 15 shown in Figure 2 has been removed.

[0035] Figure 1 and Figure 2In the thermopile infrared detector 100 shown, the thermopile infrared detector 100 includes a substrate 11, an infrared detection unit 12, a peripheral circuit 13, a sealing unit 14, a sealing window 15, an infrared absorption film 16, and a waste heat wiring 17. Additionally, Figure 1 The arrow IR described in Figure 1 indicates the incident direction of infrared rays.

[0036] The infrared detection units 12 are arranged in an array at equal intervals on the surface of the substrate 11 serving as the mounting surface. The infrared detection units 12 convert the absorbed infrared rays into heat, and convert the temperature change generated due to the converted heat into an electrical signal and output it.

[0037] The peripheral circuit 13 is arranged on the substrate 11 so as to surround the plurality of infrared detection units 12 arranged in an array. Specifically, the peripheral circuit 13 is formed in a rectangular frame shape and surrounds the plurality of infrared detection units 12 arranged in an array in a rectangular shape. That is, the inner space of the rectangle surrounded by the peripheral circuit 13 becomes the infrared detection area (pixel area) 18. Then, the peripheral circuit 13 reads the electrical signals output from each of the infrared detection units 12 through the readout circuit of the substrate 11.

[0038] In addition, the peripheral circuit 13 has a plurality of electrode pads 13a. These electrode pads 13a are provided on the upper surface of the peripheral circuit 13 and are arranged outside the sealing unit 14 and the sealing window 15 described later. That is, the peripheral circuit 13 reads the electrical signals output from the infrared detection units 12 from the readout circuit of the substrate 11, and outputs the read electrical signals to the outside of the detector through the electrode pads 13a.

[0039] The sealing unit 14 is hermetically provided with respect to the upper surface of the peripheral circuit 13. The sealing unit 14 is a sealing frame formed in a rectangular frame shape. Therefore, the sealing unit 14 surrounds the inner space of the peripheral circuit 13, that is, the periphery of the infrared detection area 18 in a rectangular shape on the upper surface of the peripheral circuit 13.

[0040] The sealing window 15 is also hermetically provided with respect to the upper surface of the sealing unit 14. The sealing window 15 is formed in a flat rectangular shape. The size of the sealing unit 14 is the same as the size of the sealing window 15. Therefore, the space surrounded by the surface of the substrate 11, the inner surface and the upper surface of the peripheral circuit 13, the inner surface of the sealing unit 14, and the back surface of the sealing window 15 is in a sealed state. That is, all the infrared detection units 12 are arranged in a sealed space.

[0041] The infrared absorption film 16 absorbs infrared rays as stray light. The infrared absorption film 16 is provided on at least the surface of the inner part of the sealing unit 14 among the surfaces of the peripheral circuit 13. Figure 1 and Figure 2This is an example in which the infrared absorption film 16 is provided so as to cover the entire surface area of the inner portion of the cover seal portion 14.

[0042] The waste heat wiring 17 is provided inside the peripheral circuit 13. The waste heat wiring 17 thermally connects the substrate 11 and the infrared absorption film 16. Therefore, the waste heat wiring 17 can transfer the heat of the infrared rays (stray light) absorbed by the infrared absorption film 16 to the substrate 11. At least one waste heat wiring 17 may be provided. Figure 1 This is an example in which a plurality of waste heat wirings 17 are provided.

[0043] Here, generally, the infrared rays sent to the thermal infrared detector 100 enter the infrared detection unit 12 through the seal window 15, and an electric signal corresponding to the temperature change of the heat of the incident infrared rays is output.

[0044] In contrast, among the infrared rays sent to the thermal infrared detector, there are infrared rays that pass through the seal window 15 but do not enter the infrared detection unit 12 and enter the surface of the peripheral circuit 13 inside the seal portion 14. In this way, the infrared rays (hereinafter, stray light) incident on the surface of the peripheral circuit may be reflected on the surface of the peripheral circuit and then enter the infrared detection unit 12 after scattering on the inner surface of the seal portion, the front and back surfaces of the seal window, or these surfaces. In this case, the detection accuracy of the temperature change of the infrared rays of the thermal infrared detector may be reduced.

[0045] Therefore, in the thermal infrared detector 100 of Embodiment 1, an infrared absorption film 16 is provided on the inner portion of the seal portion 14 on the surface of the peripheral circuit 13 where stray light may enter. Therefore, the infrared absorption film 16 can absorb the heat of the stray light. As a result, the thermal infrared detector 100 can suppress the reduction in detection accuracy caused by the stray light.

[0046] In addition, the heat of the stray light absorbed by the infrared absorption film 16 is discharged to the substrate 11 through the waste heat wiring 17. At this time, the substrate 11 functions as a radiator with a large heat capacity, so it can immediately absorb the heat of the stray light. Therefore, the thermal infrared detector 100 can reduce the thermal noise caused by the heat of the stray light. In addition, the thermal infrared detector 100 can suppress the light absorption portion of the infrared absorption film 16 that has absorbed the stray light from becoming a new heat source.

[0047] Next, use in sequence Figures 3A to 3E The manufacturing method of the thermal infrared detector 100 of Embodiment 1 will be described. In addition, Figures 3A to 3D This is a cross-sectional view showing the right half part in the process of manufacturing the thermal infrared detector 100, and a structure identical to that of the right half part is symmetrically arranged in line in the omitted left half part.

[0048] First, as Figure 3A shown, for example, in a substrate 11 such as a Si substrate and a SOI substrate, openings are formed at predetermined positions of each unit pixel by dry etching. Further, on the surface of the substrate 11, an insulating film 102 as a SiO2 film is formed by a method such as CVD (Chemical Vapor Deposition), thereby forming a trench structure 101 capable of being electrically connected to the region of the peripheral circuit 13.

[0049] Here, a SiO2 film is cited as the material for the trench structure 101 and the insulating film 102. However, any material can be used as long as it can ensure insulation between the infrared detection unit and the Si substrate and has a high etching selectivity ratio with respect to the Si substrate, and these materials are not limited to the SiO2 film.

[0050] Then, the SiO2 film on the surface of the substrate 11 is removed and planarized by a method such as CMP. After forming the insulating film 102, an infrared detection unit 12 and a peripheral circuit 13 are formed. The infrared detection unit 12 uses an element 103 that converts the detected heat into an electrical signal based on a change in voltage value. The element 103 is, for example, a semiconductor element having a temperature characteristic such as a diode or a metal film element. When multiple elements 103 are used, they are electrically connected to each other through connection wirings 104.

[0051] The waste heat wiring 17 is formed simultaneously with the peripheral circuit 13. The material of the waste heat wiring 17 only needs to be a material with high thermal conductivity. For example, Al, Cu, Co, and their compounds, TiN, Ti, Pt compounds, WSi, etc. can be cited, but it does not need to be a conductor and is not limited thereto. In particular, since the materials of Al, Cu, and their compounds are used for the multilayer wiring of the circuit, the waste heat wiring 17 can be formed simultaneously when forming the circuit wiring. Therefore, the manufacturing cost of the waste heat wiring 17 is reduced.

[0052] In addition, as long as the waste heat wiring 17 can perform thermal connection, it can also be formed of multiple materials. The waste heat wiring 17 is formed by a CVD method or a PVD (Physical Vapor Deposition) method, and is formed by using photolithography technology and etching technology so as to be thermally connected to the infrared absorption film 16 within a sealing portion 14 described later. At this time, the waste heat wiring 17 thermally connected to the infrared absorption film 16 is preferably arranged so as to follow Figure 1 at least one side of the infrared detection region 18 shown. In addition, the waste heat wiring 17 can also serve as a ground wire. In the main manufacturing process, the substrate 11 is connected to the waste heat wiring 17.

[0053] Next, as Figure 3BAs shown, a plurality of heat-insulating support legs 105 are formed on the surface of the substrate 11. The heat-insulating support legs 105 have metal wirings for reading out electrical signals from the infrared detection unit 12. The heat-insulating support legs 105 are preferably TiN, Ti, Co compounds, Pt compounds, WSi, or a laminated structure thereof.

[0054] Then, a wiring 106 formed of Al and its compounds is formed on the trench structure 101. Further, an insulating film composed of an SiO2 film, a SiN film, etc. is formed on the wiring 106.

[0055] Next, using general photolithography techniques and etching techniques, the above insulating film is processed into a desired shape. Through this series of manufacturing processes, the infrared detection unit 12 is connected to the wiring 106 through a plurality of heat-insulating support legs 105. In addition, the wiring 106 is connected to the peripheral circuit 13.

[0056] Next, as Figure 3C shown, an infrared absorption film 16 composed of nitrides, oxides, etc. is formed on the surface of the peripheral circuit 13 by CVD method, PVD method, etc. Specific examples of the material of the infrared absorption film 16 can include SiN, TiN, TiO, VN, VO, CoO, CrO, NiO, etc., but in order to improve the infrared absorption rate, they can also be used as multilayer films.

[0057] In addition, in the hollowing process described later, in order to avoid etching damage to the infrared absorption film 16, an SiO2 thin film, etc. can also be provided on the infrared absorption film 16 within a range that does not cause heat insulation.

[0058] Then, the infrared absorption film 16 formed on the surface other than the surface of the peripheral circuit 13 is removed using photolithography techniques and etching techniques. In the main manufacturing process, the substrate 11 and the infrared absorption film 16 are thermally connected through the waste heat wiring 17.

[0059] Next, as Figure 3D shown, the substrate 11 is etched using an etching gas with a high etching selectivity ratio such as Si and SiO2. Therefore, for the substrate 11, hollow heat insulation of the infrared detection unit 12 and the heat-insulating support legs 105 is achieved.

[0060] And, Figure 3E is a schematic cross-sectional view of the entire thermal infrared detector 100 after the main manufacturing process.

[0061] Finally, as Figure 2As shown, the infrared detection unit 12 is hermetically sealed. Specifically, a sealing portion 14 made of a metal multilayer film is formed on the surface of the peripheral circuit 13. The sealing portion 14 is formed of a metal multilayer film made of, for example, Au, Ni, and Cr. The metal multilayer film is formed using plating and PVD methods, etc. Also, a metal multilayer film made of, for example, Au, Ni, and Cr is formed on the outer peripheral portion of the lower surface of the sealing window 15.

[0062] In addition, the sealing window 15 is usually set larger than the imaging range of the optical system, but a reflective film made of Au, Ni, and Cr can also be provided outside the imaging range of the sealing window 15. In this case, by photolithography technology and etching technology, the metal multilayer film is formed so that only the metal multilayer film remains outside the imaging range. The material of the sealing window 15 is Si, Ge, chalcogenide glass, etc.

[0063] Next, solder paste (not shown) is applied to the sealing portion 14, and the applied solder paste is overlapped with the metal multilayer film of the sealing window 15.

[0064] Next, in a vacuum chamber equipped with an upper heater and a lower heater, the sealing window 15 having the sealing portion 14 is heated. As a result, the above-mentioned solder paste melts, and the sealing portion 14 and the sealing window 15 are joined and fixed.

[0065] Next, the heating by the vacuum chamber is stopped, and the mutually joined and fixed sealing portion 14 and sealing window 15 are cooled below the melting point of the solder paste. As a result, Figure 2 the thermal infrared detector 100 shown is completed.

[0066] As described above, the thermal infrared detector 100 of Embodiment 1 includes: an infrared detection unit 12 provided on the surface of the substrate 11 and having an element 103 that converts a temperature change caused by the incidence of infrared rays into an electric signal; a peripheral circuit 13 provided on the surface of the substrate 11 so as to surround the infrared detection unit 12 and reads out the electric signal from the element 103; a sealing portion 14 provided on the peripheral circuit 13 so as to surround the infrared detection unit 12; a sealing window 15 provided on the sealing portion 14 and forms an internal space in a sealed state for housing the infrared detection unit 12 together with the substrate 11, the peripheral circuit 13, and the sealing portion 14; an infrared absorption film 16 covering at least the inner surface portion of the surface of the peripheral circuit 13; and a waste heat wiring 17 provided inside the peripheral circuit 13 and thermally connecting the substrate 11 and the infrared absorption film 16. Therefore, the thermal infrared detector 100 can discharge the heat of the absorbed stray light to the substrate 11 having a large heat capacity.

[0067] In the thermal infrared detector 100, an infrared absorption film 16 provided on the surface of the peripheral circuit 13 is electrically connected to the ground wire of the peripheral circuit 13. Therefore, the thermal infrared detector 100 can suppress a decrease in the operating speed of the peripheral circuit 13 due to an increase in capacitance.

[0068] In the thermal infrared detector 100, the infrared absorption film 16 provided on the surface of the peripheral circuit 13 is arranged so as to avoid the electrical wiring of the peripheral circuit 13. Therefore, the thermal infrared detector 100 can suppress a decrease in the operating speed of the peripheral circuit 13 due to an increase in capacitance.

[0069] In the thermal infrared detector 100, the element 103 is a plurality of diodes connected in series with each other. Therefore, the thermal infrared detector 100 can be applied to the diode type.

[0070] In the thermal infrared detector 100, the infrared absorption film 16 is formed of the same material as that of the connection wiring 104 between the diodes. Therefore, the thermal infrared detector 100 can suppress the manufacturing cost of the element 103.

[0071] In the thermal infrared detector 100, the infrared absorption film 16 is a silicon nitride film. Therefore, in the thermal infrared detector 100, since the silicon nitride film is a material used in the semiconductor manufacturing process, the manufacturing cost of the infrared absorption film 16 can be suppressed.

[0072] In the thermal infrared detector 100, the infrared absorption film 16 is a metal film that is oxidized or nitrided. Therefore, in the thermal infrared detector 100, since the metal film is a material used in the semiconductor manufacturing process, the manufacturing cost of the infrared absorption film 16 can be suppressed.

[0073] Embodiment 2.

[0074] Use Figure 4 The thermal infrared detector 200 of Embodiment 2 will be described. Figure 4 It is a cross-sectional view of the thermal infrared detector 200 of Embodiment 2. In addition, the same reference numerals are given to the structures having the same functions as those described in the above embodiments, and the description thereof is omitted.

[0075] As Figure 4 shown, the thermal infrared detector 200 of Embodiment 2 has a structure in which a waste heat wiring 27 is added to the structure of the thermal infrared detector 100 of Embodiment 1. That is, the thermal infrared detector 200 of Embodiment 2 includes waste heat wirings 17 and 27. The waste heat wirings 17 and 27 are provided inside the peripheral circuit 13. In addition, Figure 4An example is shown in which the pyroelectric infrared detector 200 includes waste heat wirings 17 and 27. However, the pyroelectric infrared detector 200 may include only the waste heat wiring 27 out of the waste heat wirings 17 and 27.

[0076] The waste heat wiring 27 thermally connects the substrate 11 and the infrared absorption film 16. At this time, the waste heat wiring 27 is disposed so as to cross the sealing portion 14. That is, one end (inner end) of the waste heat wiring 27 is disposed inside the sealing portion 14 and is thermally connected to the infrared absorption film 16. On the other hand, the other end (outer end) of the waste heat wiring 27 is disposed outside the sealing portion 14 and is thermally connected to the substrate 11.

[0077] Therefore, the waste heat wiring 27 can discharge the heat of the stray light absorbed by the infrared absorption film 16 to the outside of the infrared detection region 18. Therefore, the pyroelectric infrared detector 200 can further reduce the thermal noise caused by the heat of the stray light.

[0078] The waste heat wiring 27 is formed between the inner side and the outer side of the sealing portion 14 by a photolithography technique and an etching technique when forming the peripheral circuit 13 in the Figure 3A manufacturing process.

[0079] As described above, in the pyroelectric infrared detector 200 of the second embodiment, one end of the waste heat wiring 27 is thermally connected to the infrared absorption film 16 inside the sealing portion 14, and the other end of the waste heat wiring 27 is thermally connected to the substrate 11 outside the sealing portion 14. Therefore, the pyroelectric infrared detector 200 can discharge the heat of the stray light absorbed by the infrared absorption film 16 to the outside of the infrared detection region 18.

[0080] Embodiment 3.

[0081] Use Figure 5 to describe the pyroelectric infrared detector 300 of the third embodiment. Figure 5 is a cross-sectional view of the pyroelectric infrared detector 300 of the third embodiment. In addition, the same reference numerals are given to the structures having the same functions as those described in the above embodiments, and the description thereof is omitted.

[0082] As Figure 5 shown, the pyroelectric infrared detector 300 of the third embodiment has a structure in which an infrared absorption film 36 is provided instead of the infrared absorption film 16 and the waste heat wiring 17 of the pyroelectric infrared detector 100 of the first embodiment.

[0083] The infrared absorption film 36 absorbs infrared rays as stray light. Although the infrared absorption film 36 is disposed so as to cover the surface of the peripheral circuit 13, its outer peripheral portion is sandwiched between the substrate 11 and the sealing portion 14. Therefore, the infrared absorption film 36 is thermally connected to the sealing window 15 through the sealing portion 14.

[0084] Therefore, the infrared absorption film 36 can discharge the heat of the absorbed stray light to the sealing window 15 through the sealing portion 14. At this time, the sealing window 15 functions as a heat sink with a large heat capacity, and thus can immediately absorb the heat of the stray light.

[0085] The infrared absorption film 36 is formed Figure 3D and Figure 3E in the manufacturing process of, by photolithography technology, to remain on the sealing portion 14.

[0086] As described above, the thermal infrared detector 300 of Embodiment 3 includes: an infrared detection unit 12 disposed on the surface of the substrate 11 and having an element 103 that converts a temperature change caused by the incidence of infrared rays into an electric signal; a peripheral circuit 13 disposed on the surface of the substrate 11 so as to surround the infrared detection unit 12 and reads an electric signal from the element 103; a sealing portion 14 disposed on the peripheral circuit 13 so as to surround the infrared detection unit 12; a sealing window 15 disposed on the sealing portion 14 and together with the substrate 11, the peripheral circuit 13, and the sealing portion 14 forms an internal space in a sealed state for accommodating the infrared detection unit 12; and an infrared absorption film 36 that covers at least the inner surface portion of the surface of the peripheral circuit 13 and is thermally connected to the sealing portion 14. Therefore, the thermal infrared detector 300 can discharge the heat of the absorbed stray light to the sealing window 15 with a large heat capacity.

[0087] Embodiment 4.

[0088] Use Figure 6 to describe the thermal infrared detector 400 of Embodiment 4. Figure 6 is a cross-sectional view of the thermal infrared detector 400 of Embodiment 4. In addition, structures having the same functions as those described in the above embodiments are denoted by the same reference numerals, and their descriptions are omitted.

[0089] As Figure 6 shown, the thermal infrared detector 400 of Embodiment 4 is a structure in which waste heat wirings 17 and 47 are added to the structure of the thermal infrared detector 300 of Embodiment 3. In addition, Figure 6An example is shown in which the thermal infrared detector 400 includes waste heat wirings 17 and 47. However, the thermal infrared detector 400 may also include only the waste heat wiring 47 out of the waste heat wirings 17 and 47. In addition, the thermal infrared detector 400 may also include a waste heat wiring 27 in addition to the waste heat wirings 17 and 47.

[0090] The waste heat wiring 47 thermally connects between the substrate 11 and the infrared absorption film 36. At this time, the waste heat wiring 47 is disposed so as to cross the sealing portion 14. In addition, the waste heat wiring 47 has three ends 47a, 47b, and 47c. The first end (inner end) 47a is disposed inside the sealing portion 14 and is thermally connected to the infrared absorption film 36. The second end (central end) 47b is disposed at a position corresponding to the sealing portion 14, and the sealing portion 14 is thermally connected to the sealing window 15 through the infrared absorption film 36 and the sealing portion 14. The third end (outer end) 47c is disposed outside the sealing portion 14 and is thermally connected to the substrate 11.

[0091] Therefore, the waste heat wiring 47 can transfer the heat of the stray light absorbed by the infrared absorption film 36 from the end 47a to the end 47b and from the end 47a to the end 47c. Therefore, the waste heat wiring 47 can discharge the heat of the stray light to the sealing window 15 having a large heat capacity through the infrared absorption film 36 and the sealing portion 14. In addition, the waste heat wiring 47 can discharge the heat of the stray light to the substrate 11 having a large heat capacity. As a result, the waste heat wiring 47 can quickly discharge the heat of the stray light absorbed by the infrared absorption film 36.

[0092] The waste heat wiring 47 is Figure 3A formed to be thermally connected to the substrate 11 and the sealing portion 14 by a film forming technique, a photolithography technique, and an etching technique in the Figure 3D manufacturing process. In addition, when the infrared absorption film 16 is formed in the

[0093] manufacturing process of the waste heat wiring 47, the infrared absorption film 16 is formed to remain on the sealing portion 14 by a photolithography technique.

[0094] Embodiment 5.

[0095] Use Figure 7 and Figure 8The pyroelectric infrared detector 500 of Embodiment 5 will be described. Figure 7 It is a top view of the pyroelectric infrared detector 500 of Embodiment 5. Figure 8 It is Figure 7 A cross-sectional view taken along line VIII-VIII. In addition, structures having the same functions as those described in the above embodiments are labeled with the same reference numerals, and their descriptions are omitted.

[0096] As Figure 7 and Figure 8 shown, the pyroelectric infrared detector 500 of Embodiment 5 has a structure in which an antireflection film 59 is added to the structure of the pyroelectric infrared detector 400 of Embodiment 4.

[0097] The antireflection film 59 suppresses the reflection of infrared rays as stray light. The antireflection film 59 is further provided on the surface of the infrared absorption film 36 provided on the surface of the peripheral circuit 13. The antireflection film 59 is provided so as to cover the inner part of the sealing portion 14 on the surface of the infrared absorption film 36.

[0098] The antireflection film 59 is formed of, for example, ZnS, MgO, MgF2, and a multilayer film containing these materials, but is not limited thereto. The antireflection film 59 may be any material as long as its refractive index in the infrared wavelength band of 8 μm to 14 μm is smaller than that of the infrared absorption film 36.

[0099] Therefore, the antireflection film 59 can suppress the reflection of stray light on the surface of the infrared absorption film 36. Therefore, the stray light absorption rate of the infrared absorption film 36 is increased.

[0100] The antireflection film 59 is Figure 3C formed into a desired shape by a film formation technique, a photolithography technique, and an etching technique after the infrared absorption film 16 is formed in the manufacturing process of

[0101] As described above, the pyroelectric infrared detector 500 of Embodiment 5 includes the antireflection film 59 provided on the surface of the infrared absorption film 36. Therefore, the pyroelectric infrared detector 500 can increase the stray light absorption rate of the infrared absorption film 36.

[0102] Embodiment 6.

[0103] Use Figure 9 to describe the pyroelectric infrared detector 600 of Embodiment 6. Figure 9 It is a cross-sectional view of the pyroelectric infrared detector 600 of Embodiment 6. In addition, structures having the same functions as those described in the above embodiments are labeled with the same reference numerals, and their descriptions are omitted.

[0104] AsFigure 9 As shown, the pyroelectric infrared detector 600 of Embodiment 6 has a structure in which an infrared absorption film 66 is added to the structure of the pyroelectric infrared detector 400 of Embodiment 4.

[0105] The infrared absorption film 66 is provided on the surface of the infrared detection unit 12. The infrared absorption film 66 is formed of the same material as the infrared absorption film 36 provided on the surface of the peripheral circuit 13. Therefore, the infrared absorption rate of the infrared detection unit 12 increases, and thus the temperature sensitivity is improved. As a result, the temperature resolution of the infrared detection unit 12 is improved.

[0106] The infrared absorption film 66 is formed by leaving the infrared absorption film 16 on the surface of the infrared detection unit 12 when forming the infrared absorption film 16 using photolithography technology and etching technology in the Figure 3C manufacturing process.

[0107] As described above, in the pyroelectric infrared detector 600 of Embodiment 6, the infrared absorption film 66 formed of the same material as the infrared absorption film 36 provided on the surface of the peripheral circuit 13 is provided on the surface of the infrared detection unit 12. Therefore, the pyroelectric infrared detector 600 can increase the infrared absorption rate of the infrared detection unit 12 and improve its temperature sensitivity. As a result, the pyroelectric infrared detector 600 can improve the temperature resolution of the infrared detection unit 12.

[0108] In addition, within the scope of the present disclosure, free combinations of the respective embodiments, or modifications of any constituent elements of the respective embodiments, or omissions of any constituent elements in the respective embodiments can be made.

[0109] Industrial Applicability

[0110] The pyroelectric infrared detector of the present disclosure includes a waste heat wiring that thermally connects the substrate and the infrared absorption film. Therefore, the heat of the stray light absorbed can be discharged to the substrate having a large heat capacity, and it is suitable for use in a pyroelectric infrared detector and the like.

[0111] Reference Numeral Explanation

[0112] 11: Substrate; 12: Infrared detection unit; 13: Peripheral circuit; 13a: Electrode pad; 14: Sealing part; 15: Sealing window; 16: Infrared absorption film; 17: Waste heat wiring; 18: Infrared detection area; 27: Waste heat wiring; 36: Infrared absorption film; 47: Waste heat wiring; 47a, 47b, 47c: Ends; 59: Anti-reflection film; 66: Infrared absorption film; 101: Groove structure; 102: Insulating film; 103: Component; 104: Connection wiring; 105: Heat insulation support leg; 106: Wiring; 100, 200, 300, 400, 500, 600: Thermal infrared detectors.

Claims

1. A thermal infrared detector, characterized in that, The thermal infrared detector includes: an infrared detection unit, which is provided on the surface of the substrate and has an element that converts a temperature change caused by the incidence of infrared rays into an electrical signal; a peripheral circuit, which is provided on the surface of the substrate so as to surround the infrared detection unit and reads the electrical signal from the element; a sealing portion, which is provided on the peripheral circuit so as to surround the infrared detection unit; a sealing window, which is provided on the sealing portion and forms an internal space in a sealed state for accommodating the infrared detection unit together with the substrate, the peripheral circuit, and the sealing portion; an infrared absorption film, which covers at least the surface of the inner portion of the sealing portion among the surfaces of the peripheral circuit; and a waste heat wiring, which is provided inside the peripheral circuit and thermally connects the substrate and the infrared absorption film.

2. The thermal infrared detector according to claim 1, wherein one end of the waste heat wiring is thermally connected to the infrared absorption film, the other end of the waste heat wiring is thermally connected to the substrate outside the sealing portion.

3. A thermal infrared detector, characterized in that, The thermal infrared detector includes: an infrared detection unit, which is provided on the surface of the substrate and has an element that converts a temperature change caused by the incidence of infrared rays into an electrical signal; a peripheral circuit, which is provided on the surface of the substrate so as to surround the infrared detection unit and reads the electrical signal from the element; a sealing portion, which is provided on the peripheral circuit so as to surround the infrared detection unit; a sealing window, which is provided on the sealing portion and forms an internal space in a sealed state for accommodating the infrared detection unit together with the substrate, the peripheral circuit, and the sealing portion; and an infrared absorption film, which covers at least the surface of the inner portion of the sealing portion among the surfaces of the peripheral circuit and is thermally connected to the sealing portion.

4. The thermal infrared detector according to claim 3, wherein the thermal infrared detector includes a waste heat wiring, the waste heat wiring is provided inside the peripheral circuit, the waste heat wiring is thermally connected to the infrared absorption film inside the sealing portion, the waste heat wiring is thermally connected to the portion where the infrared absorption film and the sealing portion are thermally connected, the waste heat wiring is thermally connected to the substrate outside the sealing portion.

5. The thermal infrared detector according to any one of claims 1 to 4, wherein the thermal infrared detector includes an antireflection film, the antireflection film is provided on the surface of the infrared absorption film.

6. The thermal infrared detector according to any one of claims 1 to 5, wherein an infrared absorption film is provided on the surface of the infrared detector, and the infrared absorption film is formed of the same material as the infrared absorption film provided on the surface of the peripheral circuit.

7. The thermal infrared detector according to any one of claims 1 to 6, wherein the infrared absorption film provided on the surface of the peripheral circuit is electrically connected to the ground wire provided on the peripheral circuit.

8. The thermal infrared detector according to any one of claims 1 to 7, wherein The infrared absorption film provided on the surface of the peripheral circuit is provided in a manner to avoid the electrical wiring of the peripheral circuit.

9. The thermal infrared detector according to any one of claims 1 to 8, characterized in that The elements are a plurality of diodes connected in series with each other.

10. The thermal infrared detector according to claim 9, characterized in that The infrared absorption film is formed of the same material as the material of the connection wiring between the diodes.

11. The thermal infrared detector according to any one of claims 1 to 10, characterized in that The infrared absorption film is a silicon nitride film.

12. The thermal infrared detector according to any one of claims 1 to 11, characterized in that The infrared absorption film is a metal film that is oxidized or nitrided.

13. A method for manufacturing the thermal infrared detector according to claim 1, characterized in that The infrared detector and the peripheral circuit are formed on the surface of the substrate, When forming the peripheral circuit, the waste heat wiring is formed simultaneously, The substrate is thermally connected to the waste heat wiring, The substrate is electrically connected to the infrared detection unit and the substrate is electrically connected to the peripheral circuit, The infrared absorption film is formed on the surface of the peripheral circuit, and the infrared absorption film is thermally connected to the waste heat wiring, The sealing portion and the sealing window are joined, and the infrared detection unit is housed in the internal space.

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