JP6747334B2 - Electronic device and manufacturing method thereof - Google Patents

Description

The present invention relates to an electronic device having a vibration sensor function and a temperature sensor function in a single device, and a manufacturing method thereof.

As a sensor that can detect strain and temperature at the same time, conventionally, for example, in Patent Document 1, an insulating film is formed on a conductive substrate, and a temperature sensor material and a strain sensor material are further formed on the insulating film. The following temperature-sensitive strain composite sensor is described. In this temperature-sensitive strain composite sensor, after forming an insulating film on the surface on which either one of the temperature sensor material or the strain sensor material is formed, the other of the temperature sensor material or the strain sensor material is further overlaid thereon. By forming a film, temperature and strain can be detected simultaneously.
In this temperature-sensitive strain composite sensor, the temperature sensor material is made of iron and palladium and a small amount of impurities, and the strain sensor material is made of nitrogen, chromium and a small amount of impurities.

Further, in Patent Document 2, a flat plate-shaped composite piezoelectric body in which a piezoelectric ceramic powder is mixed in a polymer base material and a flexible electrode arranged in close contact with both surfaces of the flat plate-shaped composite piezoelectric body are provided. There is disclosed a flexible piezoelectric element including an oscillating voltage detection unit connected to a flexible electrode and a resistance detection unit connected to at least one of the flexible electrodes. In this flexible piezoelectric element, the oscillating voltage of the flexible composite piezoelectric body is detected, and the temperature dependence of the resistance value is measured based on the resistance temperature characteristic of the flexible electrode to measure the flexible composite piezoelectric body. The temperature is being detected.

JP 2001-221696 A JP, 2002-22560, A

The above-mentioned conventional technique has the following problems.
That is, in the technique described in Patent Document 1, in order to stack the temperature sensor material and the strain sensor material, it is necessary to form an insulating film between them, which causes an inconvenience that the total number of steps is increased. there were.
Further, the technique described in Patent Document 2 has a disadvantage that it cannot be used at high temperatures because it is a flat composite piezoelectric body in which a piezoelectric ceramic powder is mixed in a polymer base material such as resin.

The present invention has been made in view of the above problems, and provides an electronic device that has a vibration sensor function and a temperature sensor function, can be manufactured by a simple process, and can be used even at high temperatures, and a manufacturing method thereof. With the goal.

The present invention adopts the following configurations in order to solve the above problems. That is, the electronic device according to the first aspect of the invention includes a first metal nitride film formed of a material having a piezoelectric characteristic and a second metal nitride film formed of a material having a thermistor characteristic and laminated on the first metal nitride film. A metal nitride film, at least one or more first electrodes formed on the first metal nitride film, and at least two or more second electrodes formed on the second metal nitride film; The crystal structures of the film and the second metal nitride film are both hexagonal wurtzite type single phases.

In this electronic device, at least one or more first electrodes formed on the first metal nitride film and at least two or more second electrodes formed on the second metal nitride film are provided. Since the crystal structure of the two-metal nitride film is a hexagonal wurtzite-type single phase, the first metal nitride film and the second metal nitride film have the same crystal structure. The formed metal nitride film is laminated with better crystallinity. In particular, since both the first metal nitride film and the second metal nitride film are hexagonal wurtzite type single phase, a film having piezoelectric characteristics and a film having thermistor characteristics depending on the metal element to be nitrided. And can be obtained in a laminated state.
Further, since it has a laminated structure of a metal nitride film having a higher heat resistance than a polymer material such as a resin, it can be used at a high temperature. Also, a composite sensor device in which a temperature sensor and a vibration sensor are integrated by a laminated structure of a first metal nitride film and a second metal nitride film and an electrode structure of a first electrode and two or more second electrodes. can do.

An electronic device according to a second invention is the electronic device according to the first invention, wherein the first metal nitride film is crystalline Al—N and the second metal nitride film is of the general formula: M _x A _y N _z ( However, M represents at least one of Ti, V, Cr, Mn, Fe, Co, Ni and Cu, and A represents Al or (Al and Si) 0.70≦y/(x+y)≦0. .98, 0.4≦z≦0.5, x+y+z=1).
That is, in this electronic device, the first metal nitride film of crystalline Al—N serves as the piezoelectric layer and the underlying layer of the second metal nitride film, so that the second metal nitride film of the same crystal system as the crystalline Al—N is used. Is formed on the first metal nitride film, the M _x A _y N _z crystal can be sufficiently nitrided from the initial crystal growth of the thermistor M _x A _y N _z immediately after the start of film formation. A columnar crystallized film having an extremely small amount of nitrogen defects can be obtained, the degree of crystal orientation is further increased, and a higher B constant can be obtained.
In addition, since the first metal nitride film of crystalline Al—N and the second metal nitride film of M _x A _y N _z are relatively flexible films, the first electrode formed on the flexible base material By forming it, it becomes possible to obtain flexibility as a whole.
Furthermore, since the first metal nitride film of crystalline Al—N has a significantly higher insulating property than the second metal nitride film of M _x A _y N _z , the thermistor characteristics of the second metal nitride film have the first metal nitride film. The third insulating film is not needed between the first metal nitride film and the second metal nitride film, and is not affected by the above.

In addition, when the above "y/(x+y)" (that is, A/(M+A)) is less than 0.70, a wurtzite type single phase cannot be obtained, and only a coexisting phase with a NaCl type phase or a NaCl type phase is obtained. And a sufficiently high resistance and a high B constant cannot be obtained.
Further, when the above-mentioned "y/(x+y)" (that is, A/(M+A)) exceeds 0.98, the resistivity is extremely high and the insulating property is extremely high, so that it cannot be applied as a thermistor material.
Further, when the above “z” (that is, N/(M+A+N)) is less than 0.4, the wurtzite type single phase cannot be obtained because the nitriding amount of the metal is small, and the high resistance and high B are sufficiently high. Can't get constant and.
Furthermore, if the above "z" (that is, N/(M+A+N)) exceeds 0.5, a wurtzite single phase cannot be obtained. This is because in the wurtzite single phase, the stoichiometric ratio when there is no defect at the nitrogen site is 0.5 (that is, N/(M+A+N)=0.5).

An electronic device according to a third invention is the electronic device according to the second invention, wherein the first metal nitride film having the first electrode formed thereon and the second metal nitride film having the second electrode formed thereon are stacked. And a base material is an insulating film.
That is, in this electronic device, since the base material is the insulating film and the first metal nitride film and the second metal nitride film are flexible films, flexibility can be obtained as a whole. When pressed against an object to be measured, it can be flexibly curved and brought into surface contact with the object to be measured, which improves the freedom of installation of the device and also provides flexibility, high vibration response, and high temperature response. It is possible to obtain an electronic device having both.

An electronic device according to a fourth invention is characterized in that, in the second or third invention, the second metal nitride film is Ti—Al—N.
That is, in this electronic device, since the second metal nitride film is Ti—Al—N, the first metal nitride film of crystalline Al—N and Al are the common element, and a film with higher crystallinity is obtained. To be

An electronic device manufacturing method according to a fifth invention is a method for manufacturing the electronic device according to any one of the second to fourth inventions, wherein an Al sputtering target is used on the first electrode in a nitrogen-containing atmosphere. A first nitride film forming step of performing reactive sputtering to form the first metal nitride film, and an MA alloy sputtering target (where M is Ti, V, Cr, or the like) on the first metal nitride film. At least one of Mn, Fe, Co, Ni, and Cu is shown, and A is Al or (Al and Si)), and reactive sputtering is performed in a nitrogen-containing atmosphere to perform the second metal nitride film. A second nitride film forming step of forming a film, and a second electrode forming step of forming the second electrode on the second metal nitride film.
That is, in this method of manufacturing an electronic device, a MA alloy sputtering target (where M is Ti, V, Cr, Mn, Fe, Co, Ni and Cu) is formed on the crystalline Al—N first metal nitride film. At least one of the above, and A represents Al or (Al and Si)) is formed by reactive sputtering in a nitrogen-containing atmosphere, so that the crystallinity is good and the degree of crystal orientation is strong. The second metal nitride film made of M _x A _y N _z can be epitaxially grown. Further, no heat treatment is required, and a high B constant can be obtained as a thermistor.
Since the crystalline Al-N does not require heat treatment and has piezoelectric characteristics, a laminated structure of the first metal nitride film having piezoelectric characteristics and the second metal nitride film having thermistor characteristics can be obtained without heat treatment, and the temperature sensor A composite sensor device in which the vibration sensor and the vibration sensor are integrated can be easily obtained.

An electronic device manufacturing method according to a sixth aspect of the present invention is the method of manufacturing the electronic device according to any one of the second to fourth aspects of the invention, wherein the M-A alloy sputtering target (provided that M Represents at least one of Ti, V, Cr, Mn, Fe, Co, Ni and Cu, and A represents Al or (Al and Si)) in a nitrogen-containing atmosphere. A second nitride film forming step of forming the second metal nitride film
A first nitride film forming step of forming a first metal nitride film by performing reactive sputtering on the second metal nitride film in an atmosphere containing nitrogen using an Al sputtering target;
A first electrode forming step of forming the first electrode on the first metal nitride film.

The present invention has the following effects.
That is, according to the electronic device of the present invention, the first electrode formed on the first metal nitride film having a piezoelectric characteristic and at least two or more first electrodes formed on the second metal nitride film having a thermistor characteristic. Since the first metal nitride film and the second metal nitride film have two electrodes and both have a hexagonal wurtzite type single phase crystal structure, an insulating film is not necessary between the films. It can be used at high temperature. Further, by integrating the temperature sensor and the vibration sensor with the laminated structure and the electrode structure, the entire size can be reduced.
Therefore, the electronic device of the present invention can be manufactured at a lower cost and smaller size than conventional ones, and can be used even in a high temperature environment. It is suitable for a module that detects both pressure and pressure at the same time. It can also be used as an energy harvester, vibrating and generating electricity with the first metal nitride film having piezoelectric characteristics, and measuring the power with the second metal nitride film having thermistor characteristics. It can be used as.
Further, in the method for manufacturing an electronic device according to the present invention, a film is formed on the first metal nitride film of crystalline Al—N by performing reactive sputtering in a nitrogen-containing atmosphere using the above MA alloy sputtering target. Therefore, it is possible to epitaxially grow the second metal nitride film made of M _x A _y N _z having good crystallinity and strong crystal orientation.

FIG. 1 is a conceptual cross-sectional view of an electronic device in the first embodiment of the electronic device and the manufacturing method thereof according to the present invention. FIG. 3 is a plan view showing an electronic device in the first embodiment. FIG. 5 is a plan view showing the manufacturing process of the electronic device in the order of processes in the first embodiment. FIG. 9 is a plan view showing a manufacturing process of the electronic device in the order of processes in the second embodiment of the electronic device and the manufacturing method thereof according to the present invention. FIG. 6 is a conceptual cross-sectional view of an electronic device according to another embodiment of the electronic device and the manufacturing method thereof according to the present invention.

Hereinafter, a first embodiment of an electronic device and a method of manufacturing the same according to the present invention will be described with reference to FIGS. 1 to 3. In the drawings used in the following description, the scale is appropriately changed as necessary in order to make each unit recognizable or easily recognizable.

The electronic device 1 of the present embodiment is a composite sensor device in which a thermistor and a vibration sensor are integrated, and as shown in FIGS. 1 and 2, is formed on a base material 2 and has a piezoelectric property. Formed on the lower surface of the first metal nitride film 3, and a second metal nitride film 4 formed of a material having thermistor characteristics and laminated on the first metal nitride film 3. The first electrode 5 and at least two second electrodes 6, 7, 8 formed on the upper surface of the second metal nitride film 4 are provided.

The crystal structures of the first metal nitride film 3 and the second metal nitride film 4 each have a hexagonal wurtzite type single phase, and the degree of c-axis orientation is higher than the degree of c-axis orientation in the film thickness direction. It is a metal nitride film having a large crystal orientation.
The crystal phase is identified by Grazing Incidence X-ray Diffraction, the tube is made of Cu, and the incident angle is 1 degree. The determination of whether the a-axis orientation (100) or the c-axis orientation (002) is strong in the direction perpendicular to the film surface (thickness direction) is made by using the above X-ray diffraction (XRD) to determine the crystal axis. Of (100) (hkl index indicating a-axis orientation) and (002) (hkl index indicating c-axis orientation), and the peak intensity ratio of “(100) peak intensity”/“(002 If the “peak intensity of )” is less than 1, the c-axis orientation is strong. An electron diffraction image of the film cross section was acquired using a TEM (transmission electron microscope), and it was confirmed that both the first metal nitride film 3 and the second metal nitride film 4 have a high degree of c-axis orientation in the film thickness direction. Has been done.
Further, both the first metal nitride film 3 and the second metal nitride film 4 are dense films, and it has been observed that columnar crystals grow in the direction perpendicular to the substrate surface. Note that the evaluation of the crystal morphology was carried out by the cross section SEM and the cross section TEM.
From the above results, the first metal nitride film 3 and the second metal nitride film 4 are dense columnar crystals each having a crystal orientation with a large degree of c-axis orientation in the direction perpendicular to the substrate surface (thickness direction). It can be seen that it is a chemical film.
In this embodiment, the first metal nitride film 3 is crystalline Al—N.

This crystalline Al-N has a piezoelectric constant of about d ₃₃ =6 pm/V.
Note that d ₃₃ is a piezoelectric strain constant, which was evaluated by a Double Beam Laser Interferometer (DBLI) manufactured by aixACCT. In the DBLI apparatus, the displacement amount in the film thickness direction of the device including the piezoelectric layer is measured by the laser irradiated from the upper surface and the lower surface of the device with respect to the potential difference applied between the first electrode and the second electrode, and the device voltage per voltage is measured. As the average value of the displacement amount in the film thickness direction, d ₃₃ can be obtained. Specifically, the measurement was performed under the conditions of a maximum potential difference of 100 V and a frequency of 1 kHz.
As the first metal nitride film 3, in addition to crystalline Al—N, crystalline Sc—Al—N or crystalline AB—Al—N (A=Mg, which is known as a wurtzite type piezoelectric material) is used. Zn, B=Ti, Zr, Hf) and the like can also be adopted.

The second metal nitride film 4 has a general formula: M _x A _y N _z (where M represents at least one of Ti, V, Cr, Mn, Fe, Co, Ni and Cu, and A represents Al). Or (Al and Si) 0.70≦y/(x+y)≦0.98, 0.4≦z≦0.5, x+y+z=1).
In this embodiment, crystalline Ti—Al—N is used as the second metal nitride film 4.

As described above, the wurtzite crystal structure is a hexagonal space group P6 ₃ mc (No. 186), and M and A belong to the same atomic site (M is Ti, V, Cr, Mn). , Fe, Co, Ni and Cu, and A is Al or (Al and Si)), which is in a so-called solid solution state. The wurtzite type has a vertex-connected structure of (M,A)N ₄ tetrahedra, and the closest site of the (M,A) site is N (nitrogen), and (M,A) has a tetracoordinated nitrogen. To take.

In addition to Ti, V (vanadium), Cr (chromium), Mn (manganese), Fe (iron), Co (cobalt), Ni (nickel), and Cu (copper) are the same as Ti in the above crystal structure. It can be present at an atomic site and can be an element of M. The effective ionic radius is a physical property value that is often used to grasp the distance between atoms. Using the well-known Shannon ionic radius literature value, it is theoretically possible to use the wurtzite M _x A _y N _z (provided that M represents at least one of Ti, V, Cr, Mn, Fe, Co, Ni and Cu, and A represents Al or (Al and Si)) can be estimated. ..
Table 1 below shows effective ionic radii of Al, Ti, V, Cr, Mn, Fe, Co, Ni, Cu, and Si ionic species (reference article RDShannon, Acta Crystallogr., Sect. A, 32, 751). (1976)).

In addition, Ti-Al-N is carrier-doped by partially substituting Ti with Al site of Al-N which is a nitride insulator having a wurtzite type crystal structure, thereby increasing electrical conductivity. Although the thermistor characteristics can be obtained, since V, Cr, Mn, Fe, Co, Ni and Cu belong to the same 3d transition metal element as Ti, wurtzite type M _x A _y N _z (however, M represents at least one of Ti, V, Cr, Mn, Fe, Co, Ni and Cu, and A represents Al or (Al and Si).), the thermistor characteristics can be obtained.

The base material 2 is an insulating film, and the first electrode 5 is formed on the upper surface thereof.
The insulating film may be made of PET: polyethylene terephthalate, PEN: polyethylene naphthalate, or the like, but a polyimide film having excellent heat resistance is desirable for applications requiring flexibility and heat resistance.
If flexibility is not required as the base material 2, a Si substrate with a thermal oxide film, a glass substrate, an insulating ceramics substrate such as alumina, or the like may be used.

Although a metal film of Cr or the like is used as the first electrode 5, a Mo film is preferable as a material from the viewpoint of the crystal orientation of the first metal nitride film 3 and the like.
The first electrode 5 is formed on the entire lower surface of the first metal nitride film 3.
As the second electrodes 6, 7, and 8, a metal film such as Mo is adopted. However, since it does not affect the crystal orientation of the metal nitride film, a single layer of the Cr film or a Cr film and an Au film. Various metal films such as a laminated metal film with a film can be adopted.

The second electrodes 6 and 7 are thermistor electrodes, and measure the temperature by measuring the ratio (resistance value) of the voltage V1 applied between them and the current flowing between them. The thermistor characteristics are evaluated in the in-film direction of the second metal nitride film. Further, these second electrodes 6 and 7 are in a state of being opposed to each other on the second metal nitride film 4, and have a comb-shaped pattern having a plurality of comb portions 6a and 7a. Although there is a first metal nitride film having piezoelectric characteristics below the second metal nitride film 4, the first metal nitride film has extremely higher insulation than the second metal nitride film. It is possible to evaluate the thermistor characteristics of the second metal nitride film without being affected by the above.

The second electrode 8 is a piezoelectric detection electrode, and a constant voltage V2 is applied between the second electrode 8 and the first electrode 5 to measure the amount of displacement (strain) to measure the piezoelectric constant. The piezoelectric characteristics are evaluated in the film thickness direction of the first metal nitride film. Between the second electrode 8 and the first metal nitride film 3, there is a second metal nitride film having thermistor characteristics, but the second metal nitride film has extremely higher conductivity than the first metal nitride film. It is possible to evaluate the piezoelectric characteristics of the first metal nitride film by using the second electrode 8 and the first electrode 5 without being affected by the second metal nitride film.
The second electrode 8 preferably has as large an area as possible in order to detect a large piezoelectric signal, and is formed in a rectangular shape with a larger area than the second electrodes 6 and 7.

On the upper surface of the base material 2, pattern wirings 9, 10, 11 which are extraction wirings connected to the corresponding second electrodes 6, 7, 8 are patterned. Further, on the upper surface of the base material 2, pattern wirings 12 which are extraction wirings connected to the first electrode 5 are formed by patterning.
Pad portions 9a to 12a for connecting lead wires are formed at the ends of the pattern wirings 9 to 12.

Next, a method of manufacturing the electronic device 1 of the present embodiment will be described with reference to FIG.
The method of manufacturing the electronic device 1 includes a first nitride film forming step of forming a first metal nitride film 3 by performing reactive sputtering on the first electrode 5 using an Al sputtering target in a nitrogen-containing atmosphere, 1 A MA alloy sputtering target on the metal nitride film 3 (where M is at least one of Ti, V, Cr, Mn, Fe, Co, Ni and Cu, and A is Al or (Al and Si)). A second nitride film forming step of forming a second metal nitride film 4 by reactive sputtering in a nitrogen-containing atmosphere, and second electrodes 6, 7 on the second metal nitride film. , 8 forming a second electrode.

More specifically, first, a Mo film is patterned on the base material 2 of polyimide resin with a Mo sputtering target to a thickness of, for example, about 100 to 200 nm. The sputtering conditions at this time are as follows: ultimate vacuum of 4.0×10 ⁻⁵ Pa, sputtering gas pressure of 0.4 Pa, target input power (output) of 300 W, and Ar gas atmosphere.
Further, as shown in FIG. 3A, the first electrode 5 is formed by patterning the Mo film thus formed by exposure patterning using a resist.
At this time, the pattern wirings 9 to 12 are also formed on the base material 2 at the same time.

Next, reactive sputtering is performed on the first electrode 5 using an Al sputtering target in a nitrogen-containing atmosphere, and as shown in FIG. 3B, the first metal nitride film 3 of the Al—N piezoelectric film is formed. The film is formed with a thickness of about 800 to 1200 nm. At this time, the sputtering conditions are as follows: ultimate vacuum of 4×10 ⁻⁵ Pa, sputtering gas pressure of 0.2 Pa, target input power (output) of 200 W, and nitrogen gas fraction in a mixed gas atmosphere of Ar gas and nitrogen gas. It was set to 35%.

Further, reactive sputtering is performed on the first metal nitride film 3 in a nitrogen-containing atmosphere using a Ti-Al alloy sputtering target, and as shown in FIG. 3C, the thermistor film (Ti-Al-N The second metal nitride film 4 (film) is formed with a thickness of about 200 nm. The sputtering conditions were such that the ultimate vacuum was 4×10 ⁻⁵ Pa, the sputtering gas pressure was 0.2 Pa, the target input power (output) was 200 W, and the nitrogen gas fraction was 30% in a mixed gas atmosphere of Ar gas and nitrogen gas. did.

Before forming the first metal nitride film 3, plasma surface treatment by reverse sputtering may be performed as a natural oxide film removing step of crystalline Al—N. The reverse sputtering conditions are, for example, ultimate vacuum: 4×10 ⁻⁵ Pa, target applied power: 50 W, and 5 minutes in Ar gas atmosphere. The gas species used in the reverse sputtering may be nitrogen gas or a mixed gas of Ar gas and nitrogen gas.
The first metal nitride film 3 and the second metal nitride film 4 are patterned into a desired shape corresponding to the first electrode 5 by exposure patterning using a metal mask or a resist.

Next, a Mo film for the second electrode is formed again on the second metal nitride film 4 with a Mo sputtering target to a thickness of about 100 to 200 nm. The sputtering conditions at this time are as follows: ultimate vacuum of 4.0×10 ⁻⁵ Pa, sputtering gas pressure of 0.4 Pa, target input power (output) of 300 W, and Ar gas atmosphere.

Further, the Mo film thus formed is subjected to exposure patterning using a resist or the like to form second electrodes 6 and 7 which are comb-shaped electrodes for temperature measurement and piezoelectric effect detection as shown in FIG. 3D. A pattern is formed on the second electrode 8 which is an electrode.
At this time, by connecting the second electrodes 6, 7, and 8 to the corresponding pattern wirings 9, 10, and 11 on the base material 2, the electronic device 1 of the present embodiment is manufactured.

When the Cr second electrodes 6, 7, and 8 are formed using a Cr sputtering target, the sputtering conditions are as follows: ultimate vacuum of 4.0×10 ⁻⁵ Pa, sputtering gas pressure of 0.1 Pa, target input power. (Output) 300 W, under Ar gas atmosphere.
Further, in the above process, the pattern wirings 9, 10, 11 are formed on the base material 2 in advance, but the pattern wirings may be formed simultaneously with the second electrodes 6, 7, 8.

As described above, in the electronic device 1 of the present embodiment, at least one or more first electrodes 5 formed on the lower surface of the first metal nitride film 3 and at least two or more second electrodes formed on the second metal nitride film 4. Since the first metal nitride film 3 and the second metal nitride film 4 are provided with the electrodes 6, 7, and 8 and both have a hexagonal wurtzite single-phase crystal structure, the first metal nitride film By having the same crystal structure as each other and the second metal nitride film, the metal nitride film formed later is laminated with better crystallinity. In particular, since both the first metal nitride film 3 and the second metal nitride film 4 are hexagonal wurtzite type single-phase, the film having piezoelectric characteristics and the thermistor characteristics are changed depending on the metal element to be nitrided. The film having the same can be obtained in a stacked state.

Further, since it has a laminated structure of a metal nitride film having a higher heat resistance than a polymer material such as a resin, it can be used at a high temperature. In addition, the laminated structure of the first metal nitride film 3 and the second metal nitride film 4 and the electrode structure of the first electrode 5 and the two or more second electrodes 6, 7, and 8 serve as a temperature sensor and a vibration sensor. Can be integrated into a composite sensor device.

Moreover, since the first metal nitride film 3 of crystalline Al—N serves as the piezoelectric layer and the underlying layer of the second metal nitride film 4, the second metal nitride film 4 of the same crystal system as the crystalline Al—N is the first layer. Since the film is formed on the 1-metal nitride film 3, the M _x A _y N _z crystal can be sufficiently nitrided after the initial crystal growth of the M _x A _y N _z for the thermistor immediately after the start of film formation. Therefore, the columnar crystallized film has an extremely small amount of nitrogen defects, the degree of crystal orientation is further increased, and a higher B constant is obtained.
In particular, since the second metal nitride film 4 is Ti—Al—N, the first metal nitride film 3 of crystalline Al—N and Al are common elements, and a film with higher crystallinity can be obtained.
Furthermore, since the first metal nitride film 3 of crystalline Al—N has a significantly higher insulating property than the second metal nitride film 4 of M _x A _y N _z , the thermistor characteristic of the second metal nitride film 4 is the first. The third insulating film is unnecessary between the first metal nitride film 3 and the second metal nitride film 4 without being affected by the metal nitride film 3.

Since the first metal nitride film 3 of crystalline Al—N and the second metal nitride film 4 of M _x A _y N _z are relatively flexible films, the first metal nitride film 3 formed on the flexible base material 2 is By forming it on one electrode 5, it becomes possible to obtain flexibility as a whole.
In particular, since the base material 2 is an insulating film, it is possible to obtain flexibility as a whole, and it becomes possible to flexibly bend and make surface contact with the measurement target when pressed against the measurement target. Therefore, the degree of freedom of installation of the device is improved, and an electronic device having flexibility, high vibration response, and high temperature response can be obtained.

Further, in the method of manufacturing the electronic device 1 of the present embodiment, the MA alloy sputtering target (where M is Ti, V, Cr, Mn, Fe, or the like) is formed on the crystalline Al—N first metal nitride film 3. At least one of Co, Ni, and Cu is shown, and A is Al or (Al and Si).) is reactively sputtered in a nitrogen-containing atmosphere to form a film. The second metal nitride film 4 made of M _x A _y N _{z having} a high degree of crystal orientation can be epitaxially grown. Further, heat treatment is unnecessary, and a thermistor having a high B constant can be obtained.
Since the crystalline Al-N does not require heat treatment and has piezoelectric characteristics, a laminated structure of the first metal nitride film having piezoelectric characteristics and the second metal nitride film having thermistor characteristics can be obtained without heat treatment, and the temperature sensor A composite sensor device in which the vibration sensor and the vibration sensor are integrated can be easily obtained.

Next, a second embodiment of the electronic device according to the present invention will be described below with reference to FIG. In the following description of the embodiments, the same components as those described in the above embodiments will be designated by the same reference numerals, and the description thereof will be omitted.

The difference between the second embodiment and the first embodiment is that in the first embodiment, three second electrodes 6, 7, and 8 are formed, whereas in the electronic device 21 of the second embodiment, As shown in (d) of FIG. 4, two second electrodes 6 and 27 are formed.
That is, in the first embodiment, the two second electrodes 6 and 7 of the thermistor electrodes and the second electrode 8 of the piezoelectric detection electrode are formed separately, but in the second embodiment, the two thermistor electrodes are formed. The difference is that one of the electrodes is shared as a piezoelectric detection electrode and the second electrode 27 is also used as a piezoelectric detection electrode.

Further, in the second embodiment, one of the thermistor electrodes and the piezoelectric detection electrode are shared, so the pattern wiring 11 connected to the second electrode 7 of the first embodiment is deleted.
That is, when manufacturing the electronic device 21 of the second embodiment, as shown in FIG. 4A, the pattern wiring 11 is not provided in the step of forming the first electrode 5 and the pattern wiring.

In this embodiment, after patterning the first metal nitride film 3 and the second metal nitride film 4 on the first electrode 5 as shown in FIGS. ), the second electrodes 6 and 27 are formed.
The second electrode 27 has a pattern in which a wide rectangular piezoelectric detection electrode portion 27b is connected to a comb-tooth electrode portion having a plurality of comb portions 7a.
Further, the piezoelectric detection electrode portion 27b is connected to the corresponding pattern wiring 10 via the connecting portion 27c.

As described above, in the electronic device 21 of the second embodiment, one of the thermistor electrodes and the piezoelectric detection electrode are shared, but as in the first embodiment, temperature measurement and piezoelectric detection can be performed simultaneously. it can.

The technical scope of the present invention is not limited to the above embodiments, and various modifications can be made without departing from the spirit of the present invention.

For example, in each of the above-described embodiments, the first electrode, the first metal nitride film, the second metal nitride film, and the second electrode are formed in this order on the base material and stacked, but the reverse is shown in FIG. Thus, the second electrode 6, the second metal nitride film 4, the first metal nitride film 3, and the first electrode 5 may be formed in this order on the base material 2 and laminated. Even in this case, both the functions of the temperature sensor and the vibration sensor can be obtained as in the above embodiments.

In addition, in the manufacturing method of this other embodiment, the MA alloy sputtering target (where M is Ti, V, Cr, Mn, Fe, Co, Ni) is formed on the second electrode 6 patterned on the base material 2. And at least one of Cu and A is Al or (Al and Si), and is subjected to reactive sputtering in a nitrogen-containing atmosphere to form the second metal nitride film 4. A film forming step, a first nitride film forming step of forming a first metal nitride film 3 on the second metal nitride film 4 by reactive sputtering in an atmosphere containing nitrogen using an Al sputtering target, A first electrode forming step of forming a first electrode 5 on the first metal nitride film 3. The film forming conditions in each of these steps are set in the same manner as in the first embodiment.

For example, even when the second metal nitride film 4 is made of crystalline Ti—Al—N and the first metal nitride film 3 made of crystalline Al—N is formed thereon, the first metal nitride film 3 is formed. The metal structures of the first and second metal nitride films 4 are both hexagonal wurtzite-type single phase and have a crystal orientation in which the c-axis orientation degree is larger than the a-axis orientation degree in the film thickness direction. It is a film. All of them are dense films, and it is observed that columnar crystals grow in the direction perpendicular to the substrate surface.

Even in this case, since the second metal nitride film 4 and the first metal nitride film 3 are both relatively flexible films, it is possible to obtain flexibility as a whole. Since the base material 2 is an insulating film, when it is pressed against the measurement target, it can be flexibly curved and brought into surface contact with the measurement target, so that the degree of freedom in installing the device is improved. Thus, an electronic device having flexibility, high vibration response and high temperature response can be obtained.

Further, the order of forming the first metal nitride film 3 and the second metal nitride film 4 may be appropriately changed when designing the device structure according to the application. For example, although Mo is used as the electrode material in this embodiment, an excellent electrode material for the first metal nitride film 3 having piezoelectric characteristics and an excellent electrode material for the second metal nitride film 4 having thermistor characteristics are used. Even when they are found and the electrode materials are different from each other, the first metal nitride film 3 and the second metal nitride film 3 are formed according to the selective etching property of the electrode material in the pattern wiring of the first electrode and the second electrode. The order of forming the film 4 can be changed.

1, 21, 31... Electronic device, 2... Base material, 3... First metal nitride film, 4... Second metal nitride film, 5... First electrode, 6, 7, 8, 27... Second electrode

Claims (6)

A first metal nitride film formed of a material having piezoelectric characteristics,
A second metal nitride film formed of a material having thermistor characteristics and laminated on the first metal nitride film;
At least one or more first electrodes formed on the first metal nitride film;
At least two second electrodes formed on the second metal nitride film,
An electronic device characterized in that the crystal structures of the first metal nitride film and the second metal nitride film are both hexagonal wurtzite single phases. The electronic device according to claim 1,
The first metal nitride film is crystalline Al-N,
The second metal nitride film has the general formula: M _x A _y N _z (where M represents at least one of Ti, V, Cr, Mn, Fe, Co, Ni and Cu, and A represents Al or ( Al and Si) 0.70≦y/(x+y)≦0.98, 0.4≦z≦0.5, x+y+z=1) An electronic device comprising a metal nitride .. The electronic device according to claim 2,
A base material on which the first metal nitride film having the first electrode formed thereon and the second metal nitride film having the second electrode formed thereon are laminated,
An electronic device, wherein the base material is an insulating film. The electronic device according to claim 2 or 3,
An electronic device, wherein the second metal nitride film is Ti-Al-N. A method of manufacturing an electronic device according to any one of claims 2 to 4, comprising:
A first nitride film forming step of forming a first metal nitride film on the first electrode by reactive sputtering in an atmosphere containing nitrogen using an Al sputtering target;
An MA alloy sputtering target (where M represents at least one of Ti, V, Cr, Mn, Fe, Co, Ni and Cu, and A represents Al or (Al and Si) on the first metal nitride film. A second nitride film forming step of forming a second metal nitride film by reactive sputtering in a nitrogen-containing atmosphere.
And a second electrode forming step of forming the second electrode on the second metal nitride film. A method of manufacturing an electronic device according to any one of claims 2 to 4, comprising:
An MA alloy sputtering target (where M represents at least one of Ti, V, Cr, Mn, Fe, Co, Ni and Cu) and A represents Al or (Al and Si) on the second electrode. A second nitride film forming step of forming the second metal nitride film by performing reactive sputtering in a nitrogen-containing atmosphere.
A first nitride film forming step of forming a first metal nitride film by performing reactive sputtering on the second metal nitride film in an atmosphere containing nitrogen using an Al sputtering target;
And a first electrode forming step of forming the first electrode on the first metal nitride film.

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