JP2023033864A - Structure and electromagnetic sensor - Google Patents

Abstract

To provide a structure that makes it possible to heighten the reliability of detection by an electromagnetic wave detection unit.SOLUTION: The present invention comprises an electromagnetic wave detection unit 4, and a pair of arm units 12a, 12b which are located on both sides across the electromagnetic wave detection unit 4. The arm units 12a, 12b include a linear conductor layer 21 which is electrically connected to the temperature detection element 5, and dielectric layers 22a, 22b which are arranged at least in part on both sides of the conductor layer 21, at least include, in a plan view, a connection unit connected to the electromagnetic wave detection unit 4, a first extension unit 23b that extends along the circumference of the electromagnetic wave detection unit 4 and a second extension unit 23d that is folded back from the first extension unit 23b via a folding unit and extends in parallel to the first extension unit 23b, and have a connection layer 24b that connects a portion of the first extension unit 23b and a portion of the second extension unit 23d to each other.SELECTED DRAWING: Figure 5

Description

The present invention relates to structures and electromagnetic wave sensors.

For example, there is an electromagnetic wave sensor using an electromagnetic wave detection part such as a thermistor element. The electrical resistance of the thermistor film of the thermistor element changes according to the temperature change of the thermistor film. In the electromagnetic wave sensor, infrared rays (electromagnetic waves) incident on the thermistor film are absorbed by the thermistor film or a material surrounding the thermistor film, thereby changing the temperature of the thermistor film. Thereby, the thermistor element detects infrared rays (electromagnetic waves).

Here, according to the Stefan-Boltzmann law, there is a correlation between the temperature of an object to be measured and infrared rays (radiant heat) emitted from the object to be measured by thermal radiation. Therefore, the temperature of the object to be measured can be measured in a non-contact manner by detecting infrared rays emitted from the object to be measured using the thermistor element.

In addition, such thermistor elements are applied to electromagnetic sensors such as infrared imaging elements (infrared image sensors) that two-dimensionally detect (image) the temperature distribution of an object to be measured by arranging them in an array. (see, for example, Patent Document 1 below).

WO2019/171488 JP 2014-38092 A

By the way, in order to perform highly accurate sensing in the above-described electromagnetic wave sensor, it is preferable that the thermistor element (electromagnetic wave detection section) is insulated from the surroundings as much as possible. On the other hand, in order to improve the heat insulation performance of the thermistor element, it is possible to make the pair of arm portions connected to the thermistor element as thin as possible. However, when the arm portion is thinned, the mechanical strength of this arm portion is lowered.

Also, the thermistor element has a structure in which it is suspended from a substrate facing the thermistor element via a pair of arm portions (see, for example, Patent Document 2 above). In this case, the thermistor element may be displaced within the plane due to a decrease in the mechanical strength of the arm portion. If the thermistor element is displaced in the plane, the reliability of detection by the thermistor element will be degraded.

The present invention has been proposed in view of such conventional circumstances, and provides a structure capable of increasing the reliability of detection by an electromagnetic wave detection unit, and an electromagnetic wave sensor equipped with such a structure. intended to provide

In order to achieve the above object, the present invention provides the following means.
[1] an electromagnetic wave detector;
A pair of arm portions located on both sides of the electromagnetic wave detection portion,
The electromagnetic wave detection unit includes a temperature detection element and an electromagnetic wave absorber covering at least a portion of the temperature detection element,
The arm portion includes a linear conductor layer electrically connected to the temperature detection element, and a dielectric layer at least a part of which is disposed on both sides of the conductor layer,
In addition, in a plan view, a connection portion connected to the electromagnetic wave detection portion, a first extension portion extending along the periphery of the electromagnetic wave detection portion, and from the first extension portion through a folded portion At least a second extension portion that is folded back and extends in parallel with the first extension portion,
A structure comprising a connection layer connecting between a portion of the first extension and a portion of the second extension.
[2] The structure according to [1] above, further comprising a connection layer that connects a portion of the electromagnetic wave detection section and a portion of the first extension portion.
[3] an electromagnetic wave detector;
A pair of arm portions located on both sides of the electromagnetic wave detection portion,
The electromagnetic wave detection unit includes a temperature detection element and an electromagnetic wave absorber covering at least a portion of the temperature detection element,
The arm portion includes a linear conductor layer electrically connected to the temperature detection element, and a dielectric layer at least a part of which is disposed on both sides of the conductor layer,
and includes at least a connecting portion connected to the electromagnetic wave detection portion and a first extension portion extending along the periphery of the electromagnetic wave detection portion in plan view,
A structure, comprising a connection layer that connects a portion of the electromagnetic wave detection portion and a portion of the first extension portion.
[4] The structure according to any one of [1] to [3], wherein the connection layer is thinner than both sides of the connection layer.
[5] Any one of [1] to [4], wherein the connection layer is thinner than the dielectric layers arranged on one side of the conductor layer. The structure described in section.
[6] An electromagnetic wave sensor comprising the structure according to any one of [1] to [5].
[7] The electromagnetic wave sensor according to [6], wherein a plurality of the structures are arranged in an array.

As described above, according to the present invention, it is possible to provide a structure capable of enhancing the reliability of detection by an electromagnetic wave detection section, and an electromagnetic wave sensor including such a structure.

It is a top view showing composition of an electromagnetic wave sensor concerning one embodiment of the present invention. FIG. 2 is an exploded perspective view showing the configuration of the electromagnetic wave sensor shown in FIG. 1; FIG. 2 is a plan view showing the configuration of a structure included in the electromagnetic wave sensor shown in FIG. 1; 4 is a cross-sectional view of the structure taken along line segment AA shown in FIG. 3; FIG. 4 is a cross-sectional view of the structure along line segment BB shown in FIG. 3; FIG. 6 is an enlarged cross-sectional view of an arm portion included in the structure shown in FIG. 5; FIG. FIG. 7 is a cross-sectional view for explaining an example of a step of forming the arm portion shown in FIG. 6; FIG. 7 is a cross-sectional view for explaining an example of a step of forming the arm portion shown in FIG. 6; FIG. 7 is a cross-sectional view for explaining an example of a step of forming the arm portion shown in FIG. 6; FIG. 7 is a cross-sectional view for explaining an example of a step of forming the arm portion shown in FIG. 6; FIG. 4 is a cross-sectional view showing another configuration example of a structure included in the electromagnetic wave sensor; FIG. 10 is a plan view showing another configuration example of a structure included in the electromagnetic wave sensor; FIG. 10 is a plan view showing another configuration example of a structure included in the electromagnetic wave sensor; FIG. 4 is a cross-sectional view showing another configuration example of the electromagnetic wave sensor;

BEST MODE FOR CARRYING OUT THE INVENTION Hereinafter, embodiments of the present invention will be described in detail with reference to the drawings.
In the drawings used in the following description, the scale of dimensions may vary depending on the component in order to make it easier to see each component, and the dimensional ratio of each component may not necessarily be the same as the actual Make it not exist. Also, the materials and the like exemplified in the following description are merely examples, and the present invention is not necessarily limited to them, and can be implemented with appropriate modifications within the scope of not changing the gist of the invention.

Further, in the drawings shown below, an XYZ orthogonal coordinate system is set, the X-axis direction is defined as the first direction X within a specific plane of the electromagnetic wave sensor, and the Y-axis direction is defined as the first direction within a specific plane of the electromagnetic wave sensor. A second direction Y perpendicular to the direction X is indicated, and the Z-axis direction is indicated as a third direction Z perpendicular to a specific plane of the electromagnetic wave sensor.

[Electromagnetic wave sensor]
First, as one embodiment of the present invention, for example, an electromagnetic wave sensor 1 shown in FIGS. 1 to 5 will be described.

1 is a plan view showing the configuration of the electromagnetic wave sensor 1. FIG. FIG. 2 is an exploded perspective view showing the configuration of the electromagnetic wave sensor 1. As shown in FIG. FIG. 3 is a plan view showing the configuration of the structure 20 included in the electromagnetic wave sensor 1. FIG. FIG. 4 is a cross-sectional view of structure 20 taken along line AA shown in FIG. FIG. 5 is a cross-sectional view of structure 20 taken along line BB shown in FIG.

The electromagnetic wave sensor 1 of the present embodiment is an infrared imaging element (infrared image sensor) that two-dimensionally detects (images) the temperature distribution of the measurement target by detecting infrared rays (electromagnetic waves) emitted from the measurement target. The present invention is applied.

Infrared rays are electromagnetic waves with a wavelength of 0.75 μm or more and 1000 μm or less. Infrared image sensors are used as infrared cameras for night vision indoors and outdoors, and are also used as non-contact temperature sensors for measuring the temperature of people and objects.

Specifically, as shown in FIGS. 1 to 5, the electromagnetic wave sensor 1 includes a first substrate 2 and a second substrate 3 arranged to face each other, and the first substrate 2 and the second substrate. and a plurality of thermistor elements 4 arranged between the substrate 3 .

The first substrate 2 and the second substrate 3 transmit electromagnetic waves of a certain wavelength, specifically infrared rays including a wavelength band of 10 μm (in this embodiment, long wavelength infrared rays of wavelengths 8 to 14 μm) IR. It consists of a silicon substrate having a A germanium substrate or the like can be used as the substrate having transparency to infrared rays IR.

The first substrate 2 and the second substrate 3 form a sealed internal space K therebetween by sealing the surfaces facing each other with a sealing material (not shown). Also, the internal space K is depressurized to a high vacuum. As a result, in the electromagnetic wave sensor 1, the influence of heat due to convection in the internal space K is suppressed, and the thermistor element 4 is excluded from the influence of heat other than the infrared rays IR emitted from the object to be measured.

It should be noted that the electromagnetic wave sensor 1 of the present embodiment is not necessarily limited to the configuration in which the sealed internal space K is depressurized as described above, and is configured to have the internal space K sealed or open under atmospheric pressure. good too.

The thermistor element 4 includes, as an electromagnetic wave detecting portion, a thermistor film 5 as a temperature detecting element, a pair of first electrodes 6 a and 6 b provided in contact with one surface of the thermistor film 5 , and the other side of the thermistor film 5 . a second electrode 6c provided in contact with the surface of the thermistor film 5; 5 has a CPP (Current-Perpendicular-to-Plane) structure in which current flows in the perpendicular direction. The insulating film 7b is provided on the opposite side of the pair of first electrodes 6a and 6b from the side in contact with the thermistor film 5. As shown in FIG.

That is, in this thermistor element 4, current flows in the direction perpendicular to the surface of the thermistor film 5 from one first electrode 6a to the second electrode 6c, and current flows from the second electrode 6c to the other first electrode 6b. A current can flow in the direction perpendicular to the plane of the thermistor film 5 toward .

As the thermistor film 5, for example, vanadium oxide, amorphous silicon, polycrystalline silicon, an oxide having a spinel crystal structure containing manganese, titanium oxide, or yttrium-barium-copper oxide can be used.

Examples of the first electrodes 6a and 6b and the second electrode 6c include platinum (Pt), gold (Au), palladium (Pd), ruthenium (Ru), silver (Ag), rhodium (Rh), iridium ( Conductive films such as Ir) and osmium (Os) can be used.

Examples of the insulating films 7a, 7b, and 7c include aluminum nitride, silicon nitride, aluminum oxide, silicon oxide, magnesium oxide, tantalum oxide, niobium oxide, hafnium oxide, zirconium oxide, germanium oxide, yttrium oxide, tungsten oxide, and bismuth oxide. , calcium oxide, aluminum oxynitride, silicon oxynitride, aluminum magnesium oxide, silicon boride, boron nitride, sialon (oxynitride of silicon and aluminum), or the like can be used.

The insulating films 7 a , 7 b , 7 c may be provided so as to cover at least a portion of the thermistor film 5 . In this embodiment, insulating films 7 a , 7 b , and 7 c are provided so as to cover both surfaces of the thermistor film 5 .

The plurality of thermistor elements 4 are formed with the same size. A plurality of thermistor elements 4 are arranged in an array in a plane parallel to the first substrate 2 and the second substrate 3 (hereinafter referred to as "specific plane"). That is, the plurality of thermistor elements 4 are arranged in a matrix in a first direction X and a second direction Y that intersect each other (perpendicularly in this embodiment) within a specific plane.

The thermistor elements 4 are arranged side by side at regular intervals in the first direction X with the first direction X as the row direction and the second direction Y as the column direction. are arranged at regular intervals.

The numbers of the thermistor elements 4 in the matrix include, for example, 640 rows×480 columns, 1024 rows×768 columns, etc., but the numbers are not necessarily limited to these numbers and can be changed as appropriate. .

On the first substrate 2 side, there are provided a first insulator layer 8, a wiring portion 9 electrically connected to a circuit portion 15 described later, and an electrical connection between each thermistor element 4 and the wiring portion 9. A first connection portion 10 for connection is provided.

The first insulator layer 8 is provided on the surface of the first substrate 2 facing the arm portions 12a and 12b (the surface facing the second substrate 3). A portion of the first insulator layer 8 faces at least portions of the arm portions 12a and 12b. The first insulator layer 8 is composed of laminated insulating films. Examples of insulating films include aluminum nitride, silicon nitride, aluminum oxide, silicon oxide, magnesium oxide, tantalum oxide, niobium oxide, hafnium oxide, zirconium oxide, germanium oxide, yttrium oxide, tungsten oxide, bismuth oxide, calcium oxide, acid Aluminum nitride, silicon oxynitride, magnesium aluminum oxide, silicon boride, boron nitride, sialon (oxynitride of silicon and aluminum), and the like can be used.

The wiring portion 9 has a plurality of first lead wires 9a and a plurality of second lead wires 9b. The first lead wire 9a and the second lead wire 9b are made of a conductive film such as copper or gold.

The plurality of first lead wires 9a and the plurality of second lead wires 9b are positioned in different layers in the third direction Z of the first insulator layer 8 and are arranged to cross three-dimensionally. It is Among them, the plurality of first lead wires 9a extend in the first direction X and are arranged side by side in the second direction Y at regular intervals. On the other hand, the plurality of second lead wires 9b extend in the second direction Y and are arranged side by side in the first direction X at regular intervals.

Each thermistor element 4 is provided in each region E partitioned by the plurality of first lead wires 9a and the plurality of second lead wires 9b in plan view. A window portion W for transmitting infrared rays IR between the first substrate 2 and the thermistor film 5 is provided in a region (overlapping region in a plan view) of each thermistor film 5 and the first substrate 2 facing each other in the thickness direction. Existing.

4 and 5, a portion facing the thermistor element 4 is provided with a hole portion 8a penetrating through the first insulator layer 8. As shown in FIGS. In other words, a hole 8a penetrating through the first insulator layer 8 is provided between the first substrate 2 and the thermistor element 4 . The hole 8a is provided in a portion of the layer T on which the first insulator layer 8 is provided, which faces the thermistor element 4. As shown in FIG.

The first connection portion 10 has a pair of first connection members 11 a and 11 b provided corresponding to each of the plurality of thermistor elements 4 . Also, the pair of first connection members 11a and 11b has a pair of arm portions 12a and 12b and a pair of leg portions 13a and 13b.

Each arm portion 12a, 12b has a conductor layer 21. As shown in FIG. The conductor layer 21 is formed of a conductor film such as aluminum, tungsten, titanium, tantalum, titanium nitride, tantalum nitride, chromium nitride, and zirconium nitride. In the examples shown in FIGS. 3 to 5, a bent line-shaped conductor layer 21 is formed along the periphery of the thermistor element 4 . Each of the leg portions 13a and 13b is composed of a conductor pillar having a circular cross section and extending in the third direction Z by plating with, for example, copper, gold, FeCoNi alloy or NiFe alloy (permalloy).

One first connection member 11a includes a conductor layer 21 included in one arm portion 12a electrically connected to one first electrode 6a, and a conductor layer 21 included in this one arm portion 12a. 21 and one leg portion 13a for electrically connecting between the first lead wire 9a and electrically connecting between one first electrode 6a and the first lead wire 9a. are doing.

The other first connection member 11b includes a conductor layer 21 included in the other arm portion 12b electrically connected to the other first electrode 6b, and a conductor layer 21 included in the other arm portion 12b. 21 and the second lead wire 9b to electrically connect the other leg portion 13b to electrically connect the other first electrode 6b and the second lead wire 9b. are doing.

As a result, the thermistor element 4 is supported in a suspended state in the third direction Z with respect to the first substrate 2 by a pair of first connection members 11a and 11b positioned diagonally in its plane. It is A space G is provided between the thermistor element 4 and the first insulator layer 8 .

Although not shown, a plurality of thermistor elements 4 for selecting one thermistor element 4 from the plurality of thermistor elements 4 are provided on one surface of the first substrate 2 (the surface facing the second substrate 3). A selection transistor (not shown) is provided. A plurality of selection transistors are provided at positions corresponding to the plurality of thermistor elements 4 on the first substrate 2 . In addition, each selection transistor is provided at a position avoiding the window portion W described above in order to prevent irregular reflection of infrared rays IR and a decrease in incidence efficiency.

On the second substrate 3 side, a second insulator layer 14, a circuit section 15 for detecting a change in voltage output from the thermistor element 4 and converting it into a brightness temperature, each thermistor element 4 and the circuit section 15 A second connection portion 16 is provided for electrically connecting between and.

The second insulator layer 14 is composed of an insulating film laminated on one surface (the surface facing the first substrate 2 ) of the second substrate 3 . As the insulating film, the same insulating film as exemplified for the first insulating layer 8 can be used.

The circuit section 15 includes a readout integrated circuit (ROIC), a regulator, an A/D converter (Analog-to-Digital Converter), a multiplexer, etc., and is provided within the second insulator layer 14 . ing.

A plurality of connection terminals 17a and 17b corresponding to the plurality of first lead wires 9a and the plurality of second lead wires 9b are provided on the surface of the second insulator layer 14, respectively. The connection terminals 17a and 17b are made of a conductive film such as copper or gold.

One of the connection terminals 17a is located in a region on one side in the first direction X surrounding the circuit portion 15 and arranged side by side in the second direction Y at regular intervals. The other connection terminals 17b are located in a region on one side in the second direction Y surrounding the circuit portion 15 and arranged side by side in the first direction X at regular intervals.

The second connection portion 16 has a plurality of second connection members 18a and 18b provided corresponding to each of the plurality of first lead wires 9a and the plurality of second lead wires 9b. The plurality of second connection members 18a and 18b are composed of conductor pillars having a circular cross section and formed to extend in the third direction Z by plating with copper or gold, for example.

One second connection member 18a electrically connects between one end side of the first lead wire 9a and one connection terminal 17a. The other second connection member 18b electrically connects between one end of the second lead wire 9b and the other connection terminal 17b. As a result, the plurality of first lead wires 9a and the circuit portion 15 are electrically connected via one of the second connection members 18a and one of the connection terminals 17a. Also, the plurality of second lead wires 9b and the circuit portion 15 are electrically connected via the other second connection member 18b and the other connection terminal 17b.

An antireflection layer 19 is provided on the side of the first substrate 2 facing the thermistor element 4 . In this embodiment, an antireflection layer 19 is provided between the first substrate 2 and the first insulator layer 8 . At least part of the antireflection layer 19 faces at least part of the thermistor element 4 . The antireflection layer 19 prevents the infrared rays IR emitted from the object to be measured from entering the thermistor film 5 from the first substrate 2 side through the window portion W, and prevents the infrared rays IR at the interface between the first substrate 2 and the space G. This is to prevent the IR from being reflected and allow the infrared ray IR that has passed through the first substrate 2 to enter the thermistor film 5 side efficiently.

As the antireflection layer 19, for example, zinc sulfide, yttrium fluoride, chalcogenide glass, germanium, silicon, zinc selenide, gallium arsenide, or the like can be used.

Alternatively, the antireflection layer 19 may have a structure in which films having different refractive indices are alternately laminated and interference of waves reflected by each layer is used to reduce the reflectance of infrared rays IR. In this case, as the antireflection layer 19, in addition to the materials described above, for example, oxide film, nitride film, sulfide film, fluoride film, boride film, bromide film, chloride film, selenide film, Ge film, A laminated film obtained by laminating a diamond film, a chalcogenide film, a Si film, or the like can be used.

In the electromagnetic wave sensor 1 of this embodiment having the configuration described above, the infrared rays IR emitted from the object to be measured enter the thermistor element 4 through the window W from the first substrate 2 side.

In the thermistor element 4, the infrared rays IR incident on the insulating films 7a, 7b, and 7c formed near the thermistor film 5 are absorbed by the insulating films 7a, 7b, and 7c, and the infrared rays IR incident on the thermistor film 5 are absorbed. is absorbed by the thermistor film 5, the temperature of the thermistor film 5 changes. Further, in the thermistor element 4, the electric resistance of the thermistor film 5 changes with the temperature change of the thermistor film 5, so that the output voltage between the pair of first electrodes 6a and 6b changes. In the electromagnetic wave sensor 1 of this embodiment, the thermistor element 4 functions as a bolometer element.

In the electromagnetic wave sensor 1 of the present embodiment, after the infrared rays IR emitted from the object to be measured are detected in a planar manner by the plurality of thermistor elements 4, the electric signals (voltage signals) output from the respective thermistor elements 4 are converted into brightness temperatures. By doing so, it is possible to two-dimensionally detect (image) the temperature distribution (temperature image) of the object to be measured.

In the thermistor element 4, when a constant voltage is applied to the thermistor film 5, it is also possible to detect a change in the current flowing through the thermistor film 5 with respect to the temperature change of the thermistor film 5 and convert it into a brightness temperature. be.

〔Structure〕
Next, as one embodiment of the present invention, a structure 20 shown in FIGS. 3 to 6, for example, will be described.
6 is an enlarged sectional view of the arm portions 12a and 12b included in the structure 20. FIG.

As shown in FIGS. 3 to 6, the structure 20 of the present embodiment includes a thermistor element 4 serving as an electromagnetic wave detection portion, and a pair of arm portions 12a and 12b positioned on both sides of the thermistor element 4. It has a structure in which the thermistor element 4 is suspended from the first substrate 2 facing the thermistor element 4 via a pair of arm portions 12a and 12b.

Each of the arm portions 12a and 12b has a linear shape. The arm portions 12a and 12b are composed of a linear conductive layer 21 electrically connected to the thermistor film 5 of the thermistor element 4, and a dielectric layer 22a at least a part of which is disposed on both sides of the conductive layer 21. , 22b. Each of the dielectric layers 22 a and 22 b has a linear shape that matches the shape of the conductor layer 21 . Also, the dielectric layers 22 a and 22 b are made of a material having a lower thermal conductivity than the conductor layer 21 .

The dielectric layers 22a, 22b are made of insulating films 7a, 7b, 7c covering the thermistor film 5 described above. Among them, a dielectric layer (hereinafter referred to as a “first dielectric layer”) 22a arranged on one surface side of the conductor layer 21 is composed of the insulating film 7a, and the other surface of the conductor layer 21 A dielectric layer (hereinafter referred to as a "second dielectric layer") 22b disposed on the side is composed of insulating films 7b and 7c. In the following description, as shown in FIG. 6, the insulating films 7a, 7b, and 7c are omitted from illustration, and are illustrated as dielectric layers 22a and 22b.

The pair of arm portions 12a and 12b are positioned on both sides of the thermistor element 4 in plan view. In the example shown in FIG. 3, a pair of arm portions 12a and 12b are arranged point-symmetrically with respect to the center of the thermistor element 4 in plan view. Each of the arm portions 12a and 12b includes, in plan view, a connecting portion 23a connected to the thermistor element 4, a first extending portion 23b extending from the connecting portion 23a along the periphery of the thermistor element 4, It has a second extension portion 23d that is folded back from the first extension portion 23b via a folded portion 23c and extends parallel to the first extension portion 23b.

That is, the arm portions 12a and 12b of the present embodiment have a plurality of (two in the present embodiment) extension portions 23b and 23d extending mainly in the first direction X and arranged side by side in the second direction Y. In addition, the end portions of these adjacent extension portions 23b and 23d are connected to each other via a folded portion 23c extending in the second direction Y. As shown in FIG.

One end of the pair of arm portions 12a and 12b is connected to the thermistor element 4 at a position sandwiching the thermistor element 4 via a connecting portion 23a extending in the second direction Y, and the other end is connected to a pair of arm portions 12a and 12b. It is connected to leg portions 13a and 13b.

By the way, the structure 20 of the present embodiment includes a connection layer 24a connecting a part of the thermistor element 4 and a part of the first extension 23b, a part of the first extension 23b, and a connection layer 24a. It has a connection layer 24b that connects with a part of the second extension 23d.

Specifically, in the structure 20 of the present embodiment, the connection layer 24a that connects between the thermistor element 4 and the first extension portion 23b is provided extending in the first direction X in plan view. ing. A connection layer 24b is provided extending in the first direction X to connect between the first extension portion 23b and the second extension portion 23d.

In addition, in the structure 20 of the present embodiment, the thickness of the connection layers 24a and 24b is thinner than both sides of the connection layers 24a and 24b in a cross-sectional view. Specifically, in the structure 20 of the present embodiment, the connection layers 24a and 24b having a thickness thinner than the first dielectric layer 22a arranged on one side with the conductor layer 21 interposed therebetween are provided. As shown in FIG. 6, the thickness ta of the connection layer 24a and the thickness tb of the connection layer 24b are smaller than the thickness t of the portion of the first dielectric layer 22a sandwiching the conductive layer 21. As shown in FIG. The connection layers 24 a and 24 b are preferably made of a material having a lower thermal conductivity than the conductor layer 21 .

As an example, these connection layers 24a and 24b are made of the insulating film 7a that forms the electromagnetic wave absorber and the first dielectric layer 22a described above. The connection layer 24a is formed so as to be continuous with the surfaces of the arm portions 12a and 12b facing the first substrate 2 while the thermistor element 4 and the first extension portion 23b are connected. It is The connection layer 24b is formed so as to be continuous with the surfaces of the arm portions 12a and 12b facing the first substrate 2 while connecting the first extension portion 23b and the second extension portion 23d. is formed in As a result, between the thermistor element 4 and the first extending portion 23b and between the first extending portion 23b and the second extending portion 23d, recesses whose bottom surfaces are the connection layers 24a and 24b, respectively. 25a and 25b are provided.

In addition, in this structure 20, the width W1 of the arms 12a and 12b in the lateral direction on the side facing the first substrate 2 is It is larger than the width W2.

Here, an example of the forming process of the arm portions 12a and 12b will be described with reference to FIGS. 7 to 10. FIG. 7 to 10 are cross-sectional views for explaining an example of the steps of forming the arm portions 12a and 12b.

In the step of forming the arm portions 12a and 12b, first, as shown in FIG. 7, aluminum oxide ( _Al.sub.2O ) is deposited on the organic sacrificial layer 30, which will be finally removed by ashing, to form the first dielectric layer 22a. ₃ ) A film 31, a titanium (Ti) film 32 to be the conductor layer 21, and an aluminum oxide (Al ₂ O ₃ ) film 33 to be the second dielectric layer 22b are sequentially laminated. The thickness of the Al ₂ O ₃ film 31 is, for example, 2000 Å, the thickness of the Ti film 32 is, for example, 600 Å, and the thickness of the Al ₂ O ₃ film 33 is, for example, 2000 Å.

Next, as shown in FIG. 8, after forming a metal film made of a nickel chromium (NiCr) film on the Al ₂ O ₃ film 33, the arm portions 12a and 12b are formed using a photolithographic technique. A mask layer 34 patterned into a shape is formed.

Next, as shown in FIG. 9, an Al ₂ O ₃ film 33, a Ti film 32 and an Al ₂ O film are formed by reactive ion etching (RIE) using chlorine (Cl) and boron chloride (BCl ₃ ) as etching gas. While patterning the _third film 31 into a shape corresponding to the mask layer 34, recesses 25a and 25b are formed.

Next, as shown in FIG. 10, the mask layer 34 is removed by dry milling. As a result, a connection layer 24a connecting a portion of the thermistor element 4 and a portion of the first extension portion 23b, a portion of the first extension portion 23b and a portion of the second extension portion 23d are formed. It is possible to form a connecting layer 24b connecting between the two parts.

As described above, in the structure 20 of the present embodiment, the thermistor element 4 can and the first extension portion 23b is suppressed, and the in-plane displacement of the thermistor element 4 can be suppressed. Further, in the structure 20 of the present embodiment, by providing the connection layer 24b that connects between a portion of the first extension portion 23b and a portion of the second extension portion 23d described above, the first The variation in the distance between the second extension portion 23b and the second extension portion 23d is suppressed, and the in-plane displacement of the thermistor element 4 can be suppressed.

Thereby, in the structure 20 of this embodiment, it is possible to improve the reliability of detection by the thermistor element 4 .

In addition, in the structure 20 of the present embodiment, since the connection layer 24a connects a part of the thermistor element 4 and a part of the first extension 23b, the thermistor element 4 and the first extension 23b are connected. 23b is suppressed by the connection layer 24a. Similarly, the connection layer 24b connects between a portion of the first extension 23b and a portion of the second extension 23d, so that the first extension 23b and the second extension 23d are connected. Heat conduction is suppressed by the connection layer 24b between the portions 23d.

Therefore, in the electromagnetic wave sensor 1 including the structure 20 of the present embodiment, heat conduction between the arm portions 12a and 12b and the thermistor element 4 is suppressed, and displacement of the thermistor element 4 within the plane is suppressed. By suppressing it, it is possible to improve the reliability of infrared IR detection by the thermistor element 4 .

It should be noted that the present invention is not necessarily limited to the above-described embodiments, and various modifications can be made without departing from the gist of the present invention.
Specifically, the above-described embodiment exemplifies the configuration in which the connection layers 24a and 24b, which are thinner than the first dielectric layer 22a arranged on one side with the conductor layer 21 interposed therebetween, are provided. However, for example, a configuration in which connection layers 24a and 24b having the same thickness as the first dielectric layer 22a are provided as shown in FIG. The connection layers 24a and 24b thinner than the total thickness of the dielectric layers 22a and 22b may be provided.

In the structure shown in FIG. 11B, the connection layers 24a and 24b may be formed using a dielectric material different from that of the first and second dielectric layers 22a and 22b.

Further, in the above embodiment, the connection layer 24a connecting a part of the thermistor element 4 and a part of the first extension 23b, a part of the first extension 23b and the second extension 23b are connected. Although a configuration in which a connection layer 24b is provided to connect between a part of the existing portion 23d and a connection layer 24b, for example, as shown in FIG. A configuration in which only a connection layer 24a is provided to connect a portion of the extension portion 23b, or a configuration in which a portion of the first extension portion 23b and the second extension portion are provided as shown in FIG. A configuration in which only the connection layer 24b that connects with a part of the portion 23d may be provided.

In the configuration shown in FIG. 12(A), the folded portion 23c and the second extension portion 23d are omitted, and the ends of the first extension portion 23b are connected to the leg portions 13a and 13b. ing. That is, the pair of arm portions 12a and 12b may have a configuration in which the folded portion 23c and the second extension portion 23d are omitted from the above configuration.

Further, as shown in FIG. 12(C), the pair of arm portions 12a and 12b are folded back from the second extending portion 23d via the folded portion 23e in addition to the above configuration, and are folded back from the second extending portion 23d. A configuration including a third extending portion 23f extending in parallel with the portion 23d may be employed. In the case of this configuration, it is also possible to adopt a configuration in which a connection layer 24c is provided to connect a portion of the second extension portion 23d and a portion of the third extension portion 23f.

That is, the "first extending portion" in the present invention is not limited to the first extending portion 23b directly connected to the connecting portion 23a in the configuration shown in FIG. The second extension portion 23d that is not folded is referred to as the "first extension portion 23d" in the present invention, and the first extension portion 23d is folded back via the folded portion 23e. The third extending portion 23f extending in parallel with 23d can also be referred to as the "second extending portion 23f" in the present invention.

Further, in the above embodiment, in plan view, the connection layer 24a is continuously provided between the thermistor element 4 and the first extension portion 23b, and the first extension portion 23b and the second extension portion 23b are connected. 23d, the connection layer 24b is continuously provided between the thermistor element 4 and the first thermistor element 4 as shown in FIGS. The connection layer 24a may be intermittently or partially provided between the extension portion 23b, and the connection layer 24b may be provided between the first extension portion 23b and the second extension portion 23d. may be intermittently or partially provided.

Further, in the above-described embodiment, the suspended electromagnetic wave sensor 1 in which the thermistor element 4 is suspended from the first substrate 2 is exemplified. It is also possible to make the electromagnetic wave sensor 1B of a suspended type suspended with respect to the substrate 3 of . In the example shown in FIG. 14, the thermistor element 4 serving as the electromagnetic wave detection section is suspended from the second substrate 3 facing the thermistor element 4 . In the electromagnetic wave sensor 1B shown in FIG. 14, the description of parts equivalent to those of the electromagnetic wave sensor 1 is omitted, and the same reference numerals are given in the drawings.

In this case, for example, the first connection members 11a and 11b are directly connected to the readout circuit (ROIC) provided on the second substrate 3 without using the second connection members 18a and 18b and the wiring portion 9. ing. In the example shown in FIG. 14, a plurality of thermistor elements 4 are arranged in a space sealed by the first substrate 2, the sealing member 26 and the second substrate 3, and are electrically connected to the readout circuit (ROIC). The electrode pads 27 are arranged outside the space.

It should be noted that the electromagnetic wave sensor to which the present invention is applied is not necessarily limited to the configuration of the infrared image sensor in which the plurality of thermistor elements 4 are arranged in an array. The present invention can also be applied to an electromagnetic wave sensor in which a plurality of thermistor elements 4 are linearly arranged. The thermistor element 4 can also be used as a temperature sensor for measuring temperature.

Further, the electromagnetic wave sensor to which the present invention is applied is not necessarily limited to those that detect the above-described infrared rays as electromagnetic waves, and may detect, for example, terahertz waves with a wavelength of 30 μm or more and 3 mm or less. .

Further, the electromagnetic wave sensor to which the present invention is applied is not necessarily limited to one using the thermistor element 4 described above as the electromagnetic wave detection section. It is possible to use, as the electromagnetic wave detection section, one using a temperature detection element such as an electro-type or a diode type.

DESCRIPTION OF SYMBOLS 1, 1A, 1B... Electromagnetic wave sensor 2... 1st board|substrate 3... 2nd board|substrate 4... Thermistor element (electromagnetic wave detection part) 5... Thermistor film (temperature detection element) 6a, 6b... 1st electrode 6c... 2nd Electrodes 7a, 7b, 7c... Insulating film (electromagnetic wave absorber) 8... First insulator layer (intermediate layer) 8a... Hole 9... Wiring part 9a... First lead wire 9b... Second lead wire 10 First connecting portions 11a, 11b First connecting members 12a, 12b Arm portions 13a, 13b Leg portions 14 Second insulator layer 15 Circuit portion 16 Second connecting portions 17a, 17b Connection terminals 18a, 18b Second connection member 19 Antireflection layer 20 Structure 21 Conductor layer 22a First dielectric layer 22b Second dielectric layer 23a Connecting portion 23b First dielectric layer Extension part 23c Folded part 23d Second extension part 24a, 24b Connection layer 25a, 25b Recess

Claims (7)

an electromagnetic wave detector;
A pair of arm portions located on both sides of the electromagnetic wave detection portion,
The electromagnetic wave detection unit includes a temperature detection element and an electromagnetic wave absorber covering at least a portion of the temperature detection element,
The arm portion includes a linear conductor layer electrically connected to the temperature detection element, and a dielectric layer at least a part of which is disposed on both sides of the conductor layer,
In addition, in a plan view, a connection portion connected to the electromagnetic wave detection portion, a first extension portion extending along the periphery of the electromagnetic wave detection portion, and from the first extension portion through a folded portion At least a second extension portion that is folded back and extends in parallel with the first extension portion,
A structure comprising a connection layer connecting between a portion of the first extension and a portion of the second extension. 2. The structure according to claim 1, further comprising a connection layer connecting a part of said electromagnetic wave detection part and a part of said first extension part. an electromagnetic wave detector;
A pair of arm portions located on both sides of the electromagnetic wave detection portion,
The electromagnetic wave detection unit includes a temperature detection element and an electromagnetic wave absorber covering at least a portion of the temperature detection element,
The arm portion includes a linear conductor layer electrically connected to the temperature detection element, and a dielectric layer at least a part of which is disposed on both sides of the conductor layer,
and includes at least a connecting portion connected to the electromagnetic wave detection portion and a first extension portion extending along the periphery of the electromagnetic wave detection portion in plan view,
A structure, comprising a connection layer that connects a portion of the electromagnetic wave detection portion and a portion of the first extension portion. 4. The structure according to any one of claims 1 to 3, wherein the connection layer is thinner than both sides of the connection layer. 5. The structure according to any one of claims 1 to 4, wherein the connection layer has a thickness smaller than that of the dielectric layers arranged on one side with the conductor layer interposed therebetween. . An electromagnetic wave sensor comprising the structure according to any one of claims 1 to 5. 7. The electromagnetic wave sensor according to claim 6, wherein a plurality of said structures are arranged in an array.

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