JP3258066B2 - Manufacturing method of thermopile type infrared sensor - Google Patents

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

BACKGROUND OF THE INVENTION 1. Field of the Invention The present invention relates to a thermopile infrared
The present invention relates to a method for manufacturing a line sensor .

[0002]

2. Description of the Related Art An example of a thermopile type infrared sensor is disclosed in Japanese Patent Application Laid-Open No. 61-259580. A conventional structure of the thermopile infrared sensor described in this publication will be described with reference to FIGS. FIG. 15 is a plan view showing the structure of a conventional thermopile infrared sensor, and FIG. 16 is a sectional view thereof. Hereinafter, description will be made with reference to FIGS. 15 and 16 alternately.

[0005] As shown in FIGS. 15 and 16, a thermopile 70 having a structure in which a plurality of thermocouples 7 made of different kinds of metals are connected in series on a substrate 1, and a hot junction portion 72 near a center of the substrate 1. Then, the cold junction portion 71 is arranged so as to be in the peripheral portion of the substrate 1, and the black body insulating film 5 is formed on the thermopile 70.
5 is covered. The black body 9 is disposed on the black body insulating film 55 so as not to cover the hot junction section 72 of the thermopile 70 and the cold junction section 71. Near the cold junction 71 on the back side or the front side of the substrate 1, a reference temperature,
That is, the thin film thermistor 3 which is a temperature detecting element for measuring the temperature of the cold junction 71 is provided.

In the thermopile type infrared sensor having the structure described in this publication, when infrared rays are incident from a measurement object,
The black body 9 absorbs the infrared rays, the temperature of the hot junction 72 of the thermopile 70 rises, and the hot junction 72 and the cold junction 71
And a temperature difference is generated between the thermocouples 7 and 8, thereby generating a thermoelectromotive force in the thermocouples 7 respectively. The thermopile 70 is added with the thermoelectromotive force of these thermocouples 7, and an output can be taken out from the thermopile extraction electrode 75. In this case, by measuring the temperature of the cold junction 71 serving as the reference temperature by the thin film thermistor 3, the amount of infrared light of the measured object can be accurately measured, and therefore, the temperature of the measured object can be measured. Further, unlike the method of measuring the reference temperature with a bulk thermistor or the like, the temperature of the cold junction 71 can be measured directly, so that a highly sensitive and small thermopile infrared sensor can be obtained.

[0005]

However, in the configuration described in this publication, a thin-film thermistor is cited as an example of the temperature detecting element. However, the specific configuration of the temperature detecting element, the electrode shape of the temperature detecting element, and the like. The method of extracting the electrodes or the method of protecting the temperature detecting element is not specified, and it is difficult to use a relatively high-resistance and unstable thin-film thermistor made of a metal oxide as the temperature detecting element.

Accordingly, an object of the present invention is to solve the above-mentioned problems and to show a method of manufacturing a thermopile type infrared sensor provided with a thin film thermistor for measuring a cold junction temperature. To provide.

[0007]

In order to achieve the above object, the present invention employs the following manufacturing method .

According to the method of manufacturing a thermopile infrared sensor of the present invention, a lower insulating film is formed on the front surface of a substrate, a thin film thermistor material is formed on the lower insulating film, and the thin film thermistor material is formed by photoetching. Forming a thermistor electrode material over the entire surface, patterning the thermistor electrode material by photoetching, forming a thermistor electrode, and forming an upper insulating film on the front surface of the substrate. Forming, forming a through hole in the upper insulating film by photoetching, forming a thermopile lead-out electrode on the front surface of the substrate, forming a thermocouple, and etching the substrate to form a pit portion And

A method for manufacturing a thermopile infrared sensor according to the present invention comprises the steps of forming a lower thermistor electrode material on the front surface of a substrate, etching the lower thermistor electrode material by photoetching, and forming a lower thermistor electrode. Forming a thin-film thermistor material on the lower thermistor electrode, etching the thin-film thermistor material by photoetching to form a thin-film thermistor; forming an upper thermistor electrode material on the thin-film thermistor; A step of forming an upper thermistor electrode by etching an electrode material, a step of forming an insulating film for a diaphragm over the entire front surface of the substrate, and a step of forming a through hole in the insulating film for the diaphragm by photoetching; Form a thermopile extraction electrode on the front surface, And a step of forming a thermocouple, and forming the pit portion of the substrate by etching.

[0010]

Embodiments of the present invention will be described below with reference to the drawings. First, a first embodiment of the present invention will be described with reference to FIGS. 1, 2, 3, 4, 5, 6, and 7. FIG. FIG. 1 is a plan view showing the structure of a thermopile infrared sensor according to the present invention, and FIG. 2 is a sectional view showing this section. Further, FIGS. 3, 4, 5, 6, and 7 are cross-sectional views showing a method for manufacturing a thermopile infrared sensor in the order of steps.

The structure of a thermopile infrared sensor according to the present invention will be described with reference to FIGS.

The front surface of the substrate 1 is covered with a lower insulating film 51, and the thin-film thermistor 3 is provided on the lower insulating film 51 near the cold junction 71. A comb-shaped thermistor electrode 31 is provided on the thin film thermistor 3, and the upper portions of the thin film thermistor 3, the thermistor electrode 31 and the lower insulating film 51 are covered with an upper insulating film 53. A through-hole 32 is formed in the insulating film 53 on the thermistor electrode lead-out portion of the thermistor electrode 31.

Therefore, the thin film thermistor 3 is protected by the upper insulating film 53 and the thermistor electrode 31.
The lower insulating film 51 and the upper insulating film 53 form the diaphragm 6 in the region of the pit 4 formed from the back side of the substrate 1. Further, on the substrate 1 where the pit portions 4 are not formed, the lower insulating film 51 and the upper insulating film 53 form the heat sink 2 together with the substrate 1.

On the upper insulating film 53, a plurality of thermocouples 7 of different metals are connected in series to form a thermopile 70. The cold junction 71 of the thermopile 70 is arranged on the heat sink 2, and the hot junction 72 is arranged on the diaphragm 6.

Further, on the upper insulating film 53, a thermopile extraction electrode 7 for obtaining an output of the thermopile 70 is provided.
5 is arranged.

In order to improve the output, a black body insulating film 55 is coated on the thermopile 70, and a black body 9 as an infrared absorber is set to be the same size as the diaphragm 6 or slightly smaller.

However, the hot junction portion 72 of the thermopile 70
In the case of a structure that can directly absorb infrared rays, the black body 9 and the insulating film 55 for the black body become unnecessary.

Further, when the black body 9 is insulative, or the black body 9 is disposed only at the hot junction 72 of each thermocouple 7, and each hot junction 72 is short-circuited by the black body 9. Otherwise, the black body insulating film 55 may not be provided.

In the thermopile type infrared sensor having the structure shown in FIGS. 1 and 2, the temperature of the diaphragm 6 rises when the hot junction 72 of the thermopile 70 or the black body 9 receives infrared rays emitted from the object to be measured. A temperature difference occurs between the hot junction 72 and the cold junction 71 of the thermopile 70.

Due to this temperature difference, a thermoelectromotive force is generated in the thermopile 70, and the output voltage of the thermopile 70 is taken out from the thermopile lead-out electrode 75. At the same time, the temperature of the cold junction 71 is measured as the resistance value of the thin film thermistor 3, It is possible to accurately measure the amount of infrared rays obtained, and accurately measure the temperature of the measured object.

Next, a method for manufacturing a thermopile infrared sensor according to the present invention will be described with reference to FIGS. 1, 2, 3, 4, 5, and 6.
This will be described with reference to FIGS. 1 and 2
Shows a completed state, and FIG. 3, FIG. 4, FIG. 5, FIG. 6, and FIG. 7 are cross-sectional views sequentially showing intermediate stages of the manufacturing process.

First, a description will be given with reference to FIG. As the substrate 1, a (100) -oriented silicon wafer is used. On the back surface of the substrate 1, a metal such as gold, various oxides, and various nitrides are used as a mask insulating film 50 for forming the pit portions 4. Alkali-insoluble film such as 200
It is formed by a vacuum evaporation method of about nm, and is patterned using a normal photo-etching technique so as to form a mask insulating film 50 in a region where the pit portion 4 is not formed.

On the front side of the substrate 1, a silicon nitride film formed by a plasma CVD method to a thickness of about 1000 nm is formed as the lower insulating film 51, and an ion plating method is formed on the silicon nitride film. To form a silicon oxide film with a thickness of about 2000 nm.

Although the lower insulating film 51 is a multilayer film in consideration of stress relaxation or mechanical strength, it may be a single-layer film, and the forming method and the film thickness can be changed.

The lower insulating film 51 and the mask insulating film 50 are used.
As a method of simultaneously constructing and using the same material,
A silicon nitride film to be the lower insulating film 51 is simultaneously formed on both the front surface and the back surface of the substrate 1 by the plasma CVD method, and the silicon nitride film also formed on the back surface is used as the mask insulating film 50. Is also possible.

On the lower insulating film 51, manganese (Mn)
Using a metal or nickel (Ni) or oxide target, the thin film thermistor 3 is formed to a thickness of about 500 nm by a sputtering method.

The conditions for forming the thin film thermistor 3 are as follows: the substrate temperature is 150 ° C., the target composition is Mn 40%,
When the high frequency power is about 200 W in an argon gas atmosphere containing 10% of oxygen with Ni being 60%, the B value showing the temperature-resistance characteristic of the thermistor is about 3000.

Of course, if the composition of Mn and Ni, the method of preparation, or the use of another substance is used, a thin film thermistor 3 having desired properties, that is, a resistivity and a B value can be obtained.

Thereafter, a photosensitive resin is formed on the entire surface of the thin-film thermistor 3, exposed using a predetermined photomask, developed, patterned, and then etched. The thin film thermistor 3 is patterned by a so-called photo-etching technique of etching the thin film thermistor 3 as a mask.

As the etchant of the thin film thermistor 3, a mixture solution of dilute hydrochloric acid and hydrogen peroxide heated to a temperature of about 50 ° C. is used.

Next, gold (A) was used as the thermistor electrode 31.
u) is formed by a vacuum evaporation method with a thickness of about 200 nm. At this time, chromium (Cr) or the like may be used as an adhesion layer for improving the adhesion between the gold of the thermistor electrode 31 and the thin film thermistor 3.

Thereafter, gold and chromium are patterned in the form of a comb as the thermistor electrode 31 by a photo-etching technique. The planar shape of the thermistor electrode 31 is shown in FIG. Comb-shaped thermistor electrodes 31 facing each other
The other side is a thermistor electrode lead-out part.

Opposite comb-shaped two thermistor electrodes 31
In the present embodiment, the distance between the two thermistor electrodes 31 is adjusted to about 10000 nm in order to set the resistance value of the thin film thermistor 3 to about 50 kΩ.

Next, a description will be given with reference to FIG. Thereafter, a silicon nitride film is formed on the entire surface as an upper insulating film 53 by about 1000 n.
m. The upper insulating film 53 is preferably formed by a plasma CVD method or the like so that the upper insulating film 53 can be formed with good step coverage even on the step portions of the thin film thermistor 3 and the thermistor electrode 31.

Thereafter, a through hole 32 is formed in the upper insulating film 53 of the thermistor electrode lead-out portion using hydrofluoric acid as an etching solution by a photoetching technique. A terminal for measuring the resistance of the thermistor is taken out from the through hole 32.

Thereafter, as the thermopile lead-out electrode 75 on the upper insulating film 53, chromium is used for the adhesion layer, gold is formed to a thickness of about 200 nm by a vacuum deposition method, and is patterned by a photoetching technique. FIG. 1 shows a planar shape of the thermopile extraction electrode 75.

Here, the thickness of the chromium of the adhesion layer is not particularly specified, but the thermistor electrode 3 when etching gold for patterning the thermopile extraction electrode 75 is used.
In order not to etch 1, a film thickness as large as a mask is preferable.

Next, a description will be given with reference to FIG. Thereafter, a photosensitive resin is formed on the entire surface, exposed using a predetermined photomask, and subjected to development processing to pattern the photosensitive resin into a predetermined shape, and thereafter, a metal is formed on the entire surface by a vacuum evaporation method. By removing the photosensitive resin and patterning a metal in a region where the photosensitive resin is not formed, the so-called lift-off method is used to pattern bismuth and antimony, respectively.
To form

At this time, either of bismuth and antimony may be formed first, but in this embodiment,
Considering that bismuth is a lower melting point metal than antimony, antimony is formed first.

The hot junction 72 of the thermopile 70
Arranged on a diaphragm 6 to be formed later, the cold junction 7
1 is provided on a heat sink 2. The planar shape of the thermopile 70 is shown in FIG.

At this time, in order to improve the adhesion of the respective contacts of bismuth and antimony, gold is patterned at the contact between the bismuth and antimony when the thermopile extraction electrode 75 is formed, and the gold is interposed therebetween. Alternatively, bismuth and antimony may be connected. Even with such a structure, the output characteristics of the thermopile do not change.

Next, a description will be given with reference to FIG. Then, the back surface of the silicon substrate 1 is etched by anisotropic etching using an etchant heated to a temperature of about 80 ° C. with a hydrazine aqueous solution in accordance with the pattern of the mask insulating film 50 to form the pit portions 4.

In this case, the thin film thermistor 3 on the front surface is not denatured because it is protected by the upper insulating film 53.

The diaphragm 6 is formed by the lower insulating film 51 and the upper insulating film 53 on the pit portion 4. The region of the substrate 1 where the pit portion 4 is not formed is the lower insulating film 51 and the upper insulating film 53. At the same time, a heat sink 2 is formed.

As a method of increasing the temperature difference between the hot junction portion 72 and the cold junction portion 71 of the thermopile 70 and improving the output, a black body 9 as an infrared absorber is provided as described with reference to FIG. do it.

That is, after the above-mentioned steps, the mask is made to adhere to the front surface of the substrate 1 using a mask in which holes of a predetermined shape are formed in a thin metal plate. An insulating film such as a silicon oxide film is formed as a black body insulating film 55 to a thickness of about several 100 nm by a so-called mask vapor deposition method.

It is advantageous to make the thickness of the black-body insulating film 55 as thin as possible as long as the insulation is maintained, since the heat capacity becomes small. The size of the black body insulating film 55 may be slightly larger than the size of the black body 9 described later.

However, when the black body 9 is a material having an insulating property, or when the black body 9 is patterned so as to be independently disposed only at the hot junction of each thermocouple 7, this black body 9 is used. It is not necessary to form the insulating film 55 for use.

Thereafter, a black body 9 as an infrared absorber is formed to a thickness of about 5000 nm by a mask evaporation method.

In the present invention, a fine particle film of gold is used as the black body 9, but any film that easily absorbs infrared rays, such as a fine particle film of a metal such as bismuth, silver, titanium, or copper, may be used.

The thickness of the black body 9 is not particularly limited, but the size of the black body 9 desirably covers the hot junction 72 of the thermopile 70 and is smaller than the diaphragm 6. The plane shape of the black body 9 is shown in FIG.

In the embodiment of the manufacturing method described above, an example in which the black body 9 is formed has been described. However, the formation of the black body 9 and the insulating film 55 for the black body becomes unnecessary for the following reasons. That is,
The hot junction portion 72 of the thermopile 70 directly absorbs infrared rays, and the amount of heat absorption is slightly smaller than the amount transmitted from the black body 9 to the hot junction portion 72 through the black body insulating film 55 by heat conduction. The output at 70 has no problem in use.

A second embodiment of the present invention will be described with reference to FIGS.
0, FIG. 11, FIG. 12, FIG. 13 and FIG. FIG. 8 is a plan view showing the structure of the thermopile infrared sensor according to the present invention, and FIG. 9 is a sectional view showing this section. 10, 11, 12, 13,
14 and 14 are sectional views showing a method for manufacturing a thermopile infrared sensor in the order of steps.

The structure of a thermopile type infrared sensor according to a second embodiment of the present invention will be described with reference to FIGS.

As shown in FIGS. 8 and 9, the thin-film thermistor 3 is installed near the cold junction 71 on the front surface of the substrate 1. This thin-film thermistor 3 has a structure that is sandwiched between a lower thermistor electrode 33 and an upper thermistor electrode 34.

A diaphragm insulating film 52 is provided on the entire surface of the substrate 1 including the region where the thin film thermistor 3 is formed, and a through hole 32 having a size slightly smaller than the upper thermistor electrode 34 is formed. Therefore, the thin film thermistor 3 is protected by the diaphragm insulating film 52 and the upper thermistor electrode 34.

Further, the diaphragm insulating film 52 forms the diaphragm 6 in the region of the pit portion 4 formed from the back side of the substrate 1.

Then, on the insulating film for diaphragm 52, a thermopile 70 provided on the upper insulating film 53, a thermopile lead-out electrode 75, an insulating film 55 for black body, and a black body 9 according to the first embodiment. Are arranged in the same shape as.

Also in the thermopile type infrared sensor having the structure shown in FIGS. 8 and 9, the thin-film thermistor 3 measures the temperature of the cold junction 71 as a resistance value in the same manner as in the first embodiment, thereby measuring the sensor. The amount of infrared light of the object can be measured accurately, and the temperature of the measured object can be measured accurately.

Next, a method of manufacturing a thermopile infrared sensor according to a second embodiment of the present invention will be described with reference to FIGS. 8, 9, 10, 11, 12, 13, and 14. FIG. 8 and 9 show the completed state,
10, 11, 12, 13, and 14 are cross-sectional views sequentially illustrating intermediate stages of a manufacturing process.

First, a description will be given with reference to FIG. As the substrate 1, a (100) -oriented silicon wafer is used.
On the back surface of the substrate 1, a film such as a metal such as gold or an alkali-insoluble film such as various oxides or various nitrides is formed as a mask insulating film 50 for forming the pit portions 4 with a thickness of 2 mm.
It is formed by a vacuum evaporation method of about 00 nm, and is patterned by using a normal photo-etching technique so as to form the mask insulating film 50 in a region where the pit portion 4 is not formed.

First, on the front surface of the substrate 1, gold is used as a material for the lower thermistor electrode, and a thickness of about 200 nm is formed by a vacuum evaporation method. At this time, it is more preferable to use chromium as the adhesion layer. There is no problem even if an insulating film such as a thermal oxide film exists on the surface of the substrate 1. The lower thermistor electrode 33 is formed by patterning the lower thermistor electrode material using gold and chromium by a photoetching technique. The planar shape of the lower thermistor electrode 33 is shown in FIG.
Shown in

Subsequently, Mn-N which becomes the thin film thermistor 3
An i-oxide film is formed to a thickness of about 500 nm by a sputtering method. The composition of the material or the manufacturing conditions
This is the same as that described in the embodiment.

This Mn—Ni oxide film is patterned using a photoetching technique to a size slightly smaller than the thermistor electrode 33 already formed, as shown in FIG. The thin film thermistor 3 is etched by using a mixed solution of dilute hydrochloric acid and hydrogen peroxide heated to a temperature of about 50 ° C.

Further, on the thin film thermistor 3, as the upper thermistor electrode 34, chromium is used for the adhesion layer and gold is
It is formed by a vacuum evaporation method of 00 nm and further patterned by photoetching. The planar shape of the upper thermistor electrode 34 is 2 as shown in FIG.
Electrodes formed of two rectangles, both of which are located inside the outer periphery of the thin film thermistor 3.

The two separated upper thermistor electrodes 34
When a current flows between the thin film thermistor 3 and the lower thermistor electrode 33, the current flows. Since the resistance value of gold is much smaller than that of the thin film thermistor 3, the resistance of the thin film thermistor 3 can be measured.

In this embodiment, the planar shape of the thin film thermistor 3 is 450 × 1000 μm, the film thickness is 500 nm as described above, and two upper thermistor electrodes 3 are formed.
4 was 400 × 200 μm, and the interval between the upper thermistor electrodes 34 was 560 μm. As a result, the resistance became about 10 kΩ.

However, the resistance value can be arbitrarily adjusted by changing the thickness and planar shape of the thin film thermistor 3 or the size and interval of the upper thermistor electrode 34.

Next, a description will be given with reference to FIG. Thereafter, a silicon nitride film is formed on the entire surface as a diaphragm insulating film 52 to a thickness of about 2 μm. The production of silicon nitride film
This is performed by a plasma CVD method.

Thereafter, the insulating film 52 for the diaphragm on the upper thermistor electrode 34 is formed by photo-etching technology.
A through hole 32 is formed. This through hole 32
Is a region from which a terminal for measuring the resistance of the thin film thermistor 3 is taken out. As shown in FIG. 8, the through hole 32 is formed one size smaller than the upper thermistor electrode 34.

The subsequent manufacturing process of the thermopile type infrared sensor and the shape or arrangement of the region formed during the manufacturing process are the same as those shown in the first embodiment.

First, a thermopile lead-out electrode 75 is formed of gold using chromium for the adhesion layer.

Subsequently, as shown in FIG. 12, bismuth and antimony are formed by a vacuum deposition method, and are further patterned by photoetching.
To form

Thereafter, as shown in FIG. 13, the back surface of the substrate 1 is etched in a hydrazine solution according to the pattern of the mask insulating film 50 to form the pits 4. At this time, the diaphragm 6 is formed by the diaphragm insulating film 52.

Finally, an insulating film such as silicon oxide is formed by a mask vapor deposition method, and a black body insulating film 55 is formed. Then, a black body 9 using a gold fine particle film is also formed by the mask vapor deposition method. .

Further, the black body insulating film 55 and the black body 9 may not be formed similarly to the first embodiment.

In the first and second embodiments described above, specific material names are given as examples of the substrate, the insulating layer, the thin film thermistor, the thermocouple, the electrode, the black body, the etchant, and the like. Obviously, other substances may be used for each purpose.

For example, in addition to silicon, the substrate 1
Glass, mica, ceramics, etc. can be applied.

The insulating films such as the lower insulating film 51, the upper insulating film 53, and the insulating film 52 for the diaphragm include nitrides of various metals such as silicon nitride, silicon oxide, alumina, tantalum oxide, and calcium fluoride. Any material having an insulating property such as an oxide, a fluoride, or an organic film may be used.

The thin-film thermistor 3 is exemplified by a composite oxide of manganese and nickel.
Any general thermistor material such as binary, ternary or quaternary oxide containing chromium or the like may be used. Further, silicon carbide or the like can be used as the thin film thermistor 3.

Further, the material of the thermocouple 7 is exemplified by bismuth and antimony, but a material in which tellurium or the like is alloyed with each may be used.

Further, the electrode materials such as the thermistor electrode 31, the upper thermistor electrode 34, the lower thermistor electrode 33, and the thermopile lead-out electrode 75 include metals such as silver, copper, aluminum and alloys thereof in addition to gold. , IT
Anything such as O (indium tin oxide) may be used.

The black body 9 is not limited to gold, and may be any metal such as silver, copper, bismuth, and aluminum, or fine particles of an oxide thereof, as long as it absorbs infrared rays.

[0084]

As described above, according to the present invention, a thin-film thermistor for measuring a cold junction temperature can be mounted on a thermopile type infrared sensor, and a high-resistance and unstable thin-film thermistor is used. Also, a highly sensitive thermopile infrared sensor can be obtained.

Further, no matter how the cold junction temperature changes,
Since the cold junction temperature can always be accurately measured, it is not necessary to take measures such as increasing the heat capacity so that the temperature of the cold junction does not fluctuate when measuring the amount of infrared rays.

[Brief description of the drawings]

FIG. 1 is a plan view showing the structure of a thermopile infrared sensor according to a first embodiment of the present invention.

FIG. 2 is a sectional view showing a structure of a thermopile infrared sensor according to a first embodiment of the present invention.

FIG. 3 is a cross-sectional view illustrating a method of manufacturing the thermopile infrared sensor according to the first embodiment of the present invention.

FIG. 4 is a cross-sectional view illustrating a method of manufacturing the thermopile infrared sensor according to the first embodiment of the present invention.

FIG. 5 is a cross-sectional view illustrating a method of manufacturing the thermopile infrared sensor according to the first embodiment of the present invention.

FIG. 6 is a cross-sectional view illustrating a method of manufacturing the thermopile infrared sensor according to the first embodiment of the present invention.

FIG. 7 is a cross-sectional view illustrating a method of manufacturing the thermopile infrared sensor according to the first embodiment of the present invention.

FIG. 8 is a plan view showing the structure of a thermopile infrared sensor according to a second embodiment of the present invention.

FIG. 9 is a sectional view showing the structure of a thermopile infrared sensor according to a second embodiment of the present invention.

FIG. 10 is a sectional view showing a method for manufacturing a thermopile infrared sensor according to a second embodiment of the present invention.

FIG. 11 is a sectional view illustrating a method for manufacturing a thermopile infrared sensor according to a second embodiment of the present invention.

FIG. 12 is a sectional view illustrating a method for manufacturing a thermopile infrared sensor according to a second embodiment of the present invention.

FIG. 13 is a cross-sectional view illustrating a method for manufacturing a thermopile infrared sensor according to a second embodiment of the present invention.

FIG. 14 is a sectional view illustrating a method for manufacturing a thermopile infrared sensor according to a second embodiment of the present invention.

FIG. 15 is a plan view showing the structure of a conventional thermopile infrared sensor.

FIG. 16 is a cross-sectional view showing the structure of a conventional thermopile infrared sensor.

[Explanation of symbols]

 Reference Signs List 1 substrate 3 thin film thermistor 6 diaphragm 7 thermocouple 31 thermistor electrode 32 through hole 33 lower thermistor electrode 34 upper thermistor electrode 51 lower insulating film 52 insulating film for diaphragm 53 upper insulating film 70 thermopile 71 cold junction part 72 hot junction part

──────────────────────────────────────────────────続 き Continued on the front page (58) Field surveyed (Int. Cl. ⁷ , DB name) H01L 35/00 G01J 1/02 G01J 5/02 G01K 7/02 H01L 35/34

Claims (2)

(57) [Claims] A lower insulating film is formed on the front surface of the substrate, a thin film thermistor material is formed on the lower insulating film, and the thin film thermistor material is patterned by photoetching to form a thin film thermistor; Further forming a thermistor electrode material on the thin film thermistor, patterning the thermistor electrode material by photoetching, forming a thermistor electrode; forming an upper insulating film on the front surface of the substrate; Forming a through hole in the upper insulating film, forming a thermopile lead-out electrode on the front surface of the substrate, forming a thermocouple, and forming a pit portion by etching the substrate. A method for producing a thermopile infrared sensor. 2. A step of forming a lower thermistor electrode material on a front surface of a substrate, etching the lower thermistor electrode material by photoetching to form a lower thermistor electrode, and forming a thin film thermistor material on the lower thermistor electrode. To form
Etching the thin film thermistor material by photoetching to form a thin film thermistor; forming an upper thermistor electrode material on the thin film thermistor;
Etching the upper thermistor electrode material by photoetching to form an upper thermistor electrode; forming an insulating film for the diaphragm over the entire front surface of the substrate; and performing a through hole in the insulating film for the diaphragm by photoetching. Forming a thermopile lead-out electrode on the front surface of the substrate to form a thermocouple; and forming a pit portion by etching the substrate. Manufacturing method of a type infrared sensor.