JP2022126582A - Thermistor element and electromagnetic sensor - Google Patents

Abstract

To provide a thermistor element in which the contact area between an electrode and a thermistor film can be enlarged.SOLUTION: A thermistor element includes a thermistor film 5, a pair of first electrodes 6a and 6b provided in contact with one surface of the thermistor film 5, an insulating film 7b provided on the side of the pair of first electrodes 6a and 6b that is opposite to the side thereof in contact with the thermistor film 5, and one or more opening parts 20a and 20b existing in regions overlapping with the pair of first electrodes 6a and 6b in a plan view and penetrating the insulating film 7b. The first electrodes 6a and 6b include a first part 61 existing in a region overlapping with the opening parts 20a and 20b in a plan view, and a second part 62 existing out of the region overlapping with the opening parts 20a and 20b in a plan view and is provided in contact with one surface of the thermistor film 5 across a region between the first part 61 and the second part 62.SELECTED DRAWING: Figure 5

Description

The present invention relates to a thermistor element and an electromagnetic wave sensor.

For example, there is a temperature sensor using a thermistor element (see, for example, Patent Document 1 below). There is also an electromagnetic wave sensor using a thermistor element (see, for example, Patent Document 2 below).

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. there is

JP 2012-156274 A WO2019/171488

By the way, as the element structure of the thermistor element described above, there are a CIP (Current-In-Plane) structure in which a current flows in the in-plane direction of the thermistor film, and a CPP (Current-Perpendicular-to-Plane) structure in which a current flows in the perpendicular direction of the thermistor film. -Plane) structure.

Of these, in the CIP structure, the thermistor film has a high resistance value. On the other hand, in the CPP structure, the resistance of the thermistor film can be made lower than in the CIP structure.

However, in the thermistor element disclosed in, for example, Patent Document 1, the electrode comes into contact with the thermistor film through the opening penetrating the insulating film. In this case, a sufficient contact area between the electrode and the thermistor film cannot be secured, resulting in a problem of reliability.

SUMMARY OF THE INVENTION The present invention has been proposed in view of such conventional circumstances. An object of the present invention is to provide an electromagnetic wave sensor capable of enhancing the performance.

In order to achieve the above object, the present invention provides the following means.
[1] a thermistor film;
a pair of first electrodes provided in contact with one surface of the thermistor film;
an insulating film provided on the opposite side of the pair of first electrodes from the side thereof in contact with the thermistor film;
at least one or more openings that penetrate through the insulating film and are positioned in a region that overlaps with each of the pair of first electrodes in plan view;
The first electrode has a first portion positioned within a region overlapping the opening in plan view, and a second portion positioned outside the region overlapping the opening in plan view,
Also, the thermistor element is provided in contact with the one surface of the thermistor film between the first portion and the second portion.
[2] comprising a wiring layer electrically connected to the first electrode;
The thermistor element according to [1], wherein the wiring layer is provided in contact with the first portion.
[3] The wiring layer according to [2] above, wherein the wiring layer is made of at least one selected from aluminum, tungsten, titanium, tantalum, titanium nitride, tantalum nitride, chromium nitride, and zirconium nitride. thermistor element.
[4] The thermistor element according to any one of [1] to [3], further comprising a second electrode provided in contact with the other surface of the thermistor film.
[5] The thermistor element according to any one of [1] to [4], wherein the area of the opening is smaller than the area of the second portion in plan view.
[6] An electromagnetic wave sensor comprising the thermistor element according to any one of [1] to [5].
[7] The electromagnetic wave sensor according to [6], wherein a plurality of the thermistor elements are arranged in an array.

According to the present invention, there are provided a thermistor element capable of increasing the contact area between an electrode and the thermistor film, and an electromagnetic wave sensor capable of improving reliability by including such a thermistor element. is possible.

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; 2 is a cross-sectional view showing the configuration of the electromagnetic wave sensor shown in FIG. 1; FIG. FIG. 4 is a plan view showing the configuration of a thermistor element included in the electromagnetic wave sensor; FIG. 5 is a cross-sectional view of the thermistor element taken along line AA shown in FIG. 4; FIG. 10 is a plan view showing a modification of the opening; 5A to 5C are cross-sectional views for sequentially explaining the steps of manufacturing the thermistor element shown in FIG. 4; 5A to 5C are cross-sectional views for sequentially explaining the steps of manufacturing the thermistor element shown in FIG. 4; 5A to 5C are cross-sectional views for sequentially explaining the steps of manufacturing the thermistor element shown in FIG. 4; 5A to 5C are cross-sectional views for sequentially explaining the steps of manufacturing the thermistor element shown in FIG. 4; 5A to 5C are cross-sectional views for sequentially explaining the steps of manufacturing the thermistor element shown in FIG. 4; 5A to 5C are cross-sectional views for sequentially explaining the steps of manufacturing the thermistor element shown in FIG. 4; 5A to 5C are cross-sectional views for sequentially explaining the steps of manufacturing the thermistor element shown in FIG. 4; 5A to 5C are cross-sectional views for sequentially explaining the steps of manufacturing the thermistor element shown in FIG. 4; FIG. 4 is a cross-sectional view showing another configuration of the thermistor element; FIG. 4 is a cross-sectional view showing another configuration of the thermistor element;

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 an embodiment of the present invention, for example, an electromagnetic wave sensor 1 shown in FIGS. 1 to 3 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 cross-sectional view showing the configuration of the electromagnetic wave sensor 1. As 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 3, 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 are transparent to electromagnetic waves of a certain wavelength (in this embodiment, long wavelength infrared rays having a wavelength of 8 to 14 μm) (hereinafter referred to as “infrared rays”) IR. It consists of a silicon substrate. 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 a thermistor film 5 for detecting infrared rays IR, a pair of first electrodes 6a and 6b provided in contact with one surface of the thermistor film 5, and the other surface of the thermistor film 5. and insulating films 7a, 7b, and 7c covering the thermistor film 5, and a CPP (Current-Perpendicular-to-Plane) structure in which current flows in the direction perpendicular to the plane of the thermistor film 5. have. 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 to have the same size in plan view. 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 composed of an insulating film laminated on one surface of the first substrate 2 (the surface facing the second substrate 3). 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 for each region 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.

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 is made of at least one selected from, for example, aluminum, tungsten, titanium, tantalum, titanium nitride, tantalum nitride, chromium nitride, and zirconium nitride. Each of the arm portions 12a and 12b is a wiring layer electrically connected to the first electrode 6a or the first electrode 6b, and is a bent linear conductor formed along the periphery of the thermistor film 5 in plan view. It is formed by a pattern and a conductor portion formed at a position overlapping the thermistor film 5 in a plan view and connected to one first electrode 6a or the other first electrode 6b. Each of the leg portions 13a and 13b is formed as a contact plug electrically connected to the first lead wire 9a or the second lead wire 9b by plating with, for example, copper, gold, FeCoNi alloy or NiFe alloy (permalloy). 3 are formed by conductor pillars having a circular cross-section and extending in the direction Z. As shown in FIG.

One first connection member 11a electrically connects one arm portion 12a electrically connected to one first electrode 6a and the one arm portion 12a and the first lead wire 9a. , and electrically connects one first electrode 6a and the first lead wire 9a.

The other first connection member 11b electrically connects the other arm portion 12b electrically connected to the other first electrode 6b and the other arm portion 12c and the second lead wire 9b. and the other leg portion 13b connected to the second lead wire 9b to electrically connect the other first electrode 6b and the second lead wire 9b.

As a result, the thermistor element 4 is supported in a suspended state in the third direction Z by a pair of first connection members 11a and 11b positioned diagonally in its plane. 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.

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.

[Thermistor element]
Next, a thermistor element 4 shown in FIGS. 4 and 5, for example, will be described as an embodiment of the present invention.
4 is a plan view showing the configuration of the thermistor element 4. FIG. FIG. 5 is a cross-sectional view of the thermistor element 4 taken along line AA shown in FIG.

As shown in FIGS. 4 and 5, the thermistor element 4 of the present embodiment includes a thermistor film 5 and a pair of first electrodes provided in contact with one surface (lower surface in FIG. 5) of the thermistor film 5. It has a CPP structure comprising 6a, 6b and a second electrode 6c provided in contact with the other surface (upper surface in FIG. 5) of the thermistor film 5. As shown in FIG.

In the thermistor element 4 of the present embodiment, for example, an oxide having a spinel crystal structure containing cobalt, manganese, and nickel (hereinafter referred to as “Co—Mn—Ni oxide”) is used as the thermistor film 5, and the first Platinum (Pt) is used as the electrodes 6a, 6b and the second electrode 6c. The thermistor element 4 is an element called NTC (Negative Temperature Coefficient) whose electric resistance decreases as the temperature rises.

In the thermistor element 4 of the present embodiment having the configuration as described above, a current is caused to flow in the direction perpendicular to the surface of the thermistor film 5 from one of the first electrodes 6a toward the second electrode 6c, and the second electrode 6c A current can flow in the direction perpendicular to the surface of the thermistor film 5 from the first electrode 6b on the other side.

The resistance value of the thermistor film 5 in the CPP structure depends on the thickness of the thermistor film 5 and the size of the facing area between the first electrodes 6a, 6b and the second electrode 6c. Therefore, by adopting the CPP structure described above, it is possible to reduce the resistance of the thermistor film 5 .

By the way, in the thermistor element 4 of the present embodiment, the insulating film 7b is located in a region overlapping with each of the pair of first electrodes 6a and 6b in plan view, and between the arm portions 12a and 12b serving as wiring layers. A pair of openings 20a and 20b are provided through the . Specifically, in the present embodiment, rectangular openings 20a and 20b are provided in substantially central portions of regions overlapping the first electrodes 6a and 6b in a plan view, respectively.

The first electrodes 6a and 6b have a first portion 61 positioned within a region overlapping the openings 20a and 20b in plan view, and a second portion 61 positioned outside the region overlapping the openings 20a and 20b in plan view. a portion 62; In each of the first electrodes 6a, 6b, the first portion 61 and the second portion 62 are electrically connected. Thus, the first electrodes 6 a and 6 b are provided in contact with one surface of the thermistor film 5 across the first portion 61 and the second portion 62 .

Thereby, in the thermistor element 4 of the present embodiment, the contact area between the first electrodes 6a and 6b and the thermistor film 5 can be increased, and the reliability of the thermistor element 4 can be improved. In addition, in the thermistor element 4 having the CPP structure of the present embodiment, the facing area between the first electrodes 6a and 6b and the second electrode 6c can be increased. It is possible to prevent the resistance value of the thermistor film 5 between the second electrode 6c and the resistance value of the thermistor film 5 between the second electrode 6c and the other first electrode 6b from becoming excessively large. be.

In addition, in the thermistor element 4 of this embodiment, the arm portions 12a and 12b (wiring layers) are in contact with the first portions 61 of the first electrodes 6a and 6b. On the other hand, the second portion 62 of each first electrode 6a, 6b is located between one surface of the thermistor film 5 and the insulating film 7b provided on each arm portion 12a, 12b (wiring layer). is sandwiched.

Further, in the thermistor element 4 of the present embodiment, as shown in FIG. 4, the area of the openings 20a and 20b (the first portion 61) is smaller than the area of the second portion 62 in plan view. . Portions of the thermistor film 5 that overlap the openings 20a and 20b in plan view tend to have poor film quality. Since the area of the portion 61) is smaller than the area of the second portion 62, the thermistor film 5 can be formed with good film quality.

In addition, in the thermistor element 4 of the present embodiment, as shown in FIG. 4, the thermistor films of the pair of first electrodes 6a and 6b are placed in the region of the second electrode 6c in contact with the thermistor film 5 in plan view. 5 are located respectively.

As a result, in the thermistor element 4 of the present embodiment, even if the first electrodes 6a and 6b are arranged in the plane of the thermistor element 4, the facing area between the first electrodes 6a and 6b and the second electrode 6c is Since there is no change, it is possible to suppress variations in the resistance value of the thermistor film 5 .

In this embodiment, the thermistor film 5, the pair of first electrodes 6a and 6b, and the second electrode 6c are formed in a substantially rectangular shape in plan view. The shapes of the pair of first electrodes 6a and 6b and the second electrode 6c can be changed as appropriate.

Further, the openings 20a and 20b are not necessarily limited to the configuration described above, and may be configured as shown in FIGS. The number and the like can be changed as appropriate.

Specifically, in the configuration shown in FIG. 6A, openings 20a and 20b are provided in the vicinity of longitudinal ends of regions overlapping the first electrodes 6a and 6b in plan view.

On the other hand, in the configuration shown in FIG. 6B, a plurality of (three in the present embodiment) openings 20a and 20b are arranged side by side in regions overlapping the first electrodes 6a and 6b in plan view. It is

On the other hand, in the configuration shown in FIG. 6C, elongated openings 20a and 20b are provided over the majority of the regions overlapping the first electrodes 6a and 6b in plan view.

Next, the manufacturing process of the thermistor element 4 will be described with reference to FIGS. 7 to 14. FIG.
7 to 14 are cross-sectional views for explaining the steps of manufacturing the thermistor element 4 in order.

When manufacturing the thermistor element 4, first, as shown in FIG. 7, an insulating film 7a made of, for example, Al ₂ O ₃ is formed over the entire surface of the organic material layer 30 .

Next, as shown in FIG. 8, after a conductive film 52 made of Ti, for example, is formed over the entire surface, the pair of arm portions 12a and 12b is formed by patterning using a photolithographic technique. Form.

Next, as shown in FIG. 9, an insulating film 7b made of, for example, Al ₂ O ₃ is formed over the entire surface of the pair of arm portions 12a and 12b.

Next, as shown in FIG. 10, openings 20a and 20b penetrating through the insulating film 7b are formed on the pair of arm portions 12a and 12b by patterning using a photolithographic technique.

Next, as shown in FIG. 11, after a conductive film 53 made of Pt, for example, is formed over the entire surface, the first electrodes 6a and 6b are formed by patterning using a photolithographic technique. Form.

Next, as shown in FIG. 12, after a thermistor material film 54 made of, for example, Co--Mn--Ni oxide is formed over the entire surface, a Pt film, for example, is deposited on the thermistor material film 54. Next, as shown in FIG. A conductive film 55 is formed over the entire surface.

Next, as shown in FIG. 13, a second electrode 6c and a thermistor film 5 patterned in the same shape are formed by patterning using a photolithographic technique. After that, heat (annealing) treatment is performed in oxygen.

Next, as shown in FIG. 14, an insulating film 7c made of, for example, SiO ₂ is formed over the entire surface. After that, the organic material layer 30 is removed by ashing. Through the steps described above, the thermistor element 4 can be manufactured.

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.

For example, in the thermistor element 4, the insulating film 7b surrounding the openings 20a and 20b is formed of a surface perpendicular to the film surface. The insulating film 7b surrounding the periphery may be formed of the inclined surface 70. As shown in FIG.

Also in this case, the contact area between the first electrodes 6a and 6b and the thermistor film 5 can be increased, and the reliability of the thermistor element 4 can be improved. Also, the resistance value of the thermistor film 5 between the first electrode 6a on one side and the second electrode 6c, and the resistance value of the thermistor film 5 between the second electrode 6c and the first electrode 6b on the other side It is possible to prevent the value from becoming too large.

In the thermistor element 4, the thickness of the first portion 61 of the first electrodes 6a and 6b is smaller than the thickness of the insulating film 7b surrounding the openings 20a and 20b. On the other hand, as shown in FIG. 16, the thickness of the first portion 61 of the first electrodes 6a and 6b may be made larger than the thickness of the insulating film 7b surrounding the openings 20a and 20b. good.

The thermistor element 4 has a CPP structure, but may have a CIP structure in which the second electrode 6c is omitted. Also in this case, the contact area between the first electrodes 6a and 6b and the thermistor film 5 can be increased, and the reliability of the thermistor element 4 can be improved.

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. It is also possible to use the thermistor element 4 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. .

Reference Signs List 1 electromagnetic wave sensor 2 first substrate 3 second substrate 4, 4A, 4B thermistor element 5 thermistor film 6a, 6b first electrode 6c second electrode 7a, 7b, 7c insulating film 8... First insulator layer 9... Wiring part 9a... First lead wire 9b... Second lead wire 10... First connection part 11a, 11a... First connection member 12a, 12b... Arm part (wiring Layer) 13a, 13b Leg portion 14 Second insulator layer 15 Circuit portion 16 Second connection portion 17a, 17b Connection terminal 18a, 18b Second connection member 20a, 20b Opening 61 1st part 62... 2nd part IR... Infrared rays (electromagnetic waves) G... Space

Claims (7)

a thermistor film;
a pair of first electrodes provided in contact with one surface of the thermistor film;
an insulating film provided on the opposite side of the pair of first electrodes from the side thereof in contact with the thermistor film;
at least one or more openings that penetrate through the insulating film and are positioned in a region that overlaps with each of the pair of first electrodes in plan view;
The first electrode has a first portion positioned within a region overlapping the opening in plan view, and a second portion positioned outside the region overlapping the opening in plan view,
Also, the thermistor element is provided in contact with the one surface of the thermistor film between the first portion and the second portion. A wiring layer electrically connected to the first electrode,
2. The thermistor element according to claim 1, wherein said wiring layer is provided in contact with said first portion. 3. The thermistor element according to claim 2, wherein the wiring layer is made of at least one selected from aluminum, tungsten, titanium, tantalum, titanium nitride, tantalum nitride, chromium nitride, and zirconium nitride. 4. The thermistor element according to claim 1, further comprising a second electrode provided in contact with the other surface of said thermistor film. 5. The thermistor element according to claim 1, wherein the area of the opening is smaller than the area of the second portion in plan view. An electromagnetic wave sensor comprising the thermistor element according to any one of claims 1 to 5. 7. The electromagnetic wave sensor according to claim 6, wherein a plurality of said thermistor elements are arranged in an array.

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