TW202418978A - Laminated structure, element, electronic device, electronic instrument and system - Google Patents

Abstract

An object of the present invention is to provide a laminated structure, an element, an electronic device, an electronic instrument and a system with excellent bending strength. The present invention use a laminated structure to manufacture a piezoelectric element or a semiconductor element, in which at least a first layer and a second layer are laminated respectively on a crystal substrate, wherein the first layer is composed of a metal compound film, the second layer is composed of a metal film of a metal that will perform martensite transformation by heat treatment or process, and the crystal substrate, the first layer and the second layer are respectively oriented in an approximately same crystal axis direction.

Description

Laminated structures, components, electronic devices, electronic machines and systems

The present invention relates to a layered structure, an electronic device, an electronic machine and a system.

There has been research on a piezoelectric film made of lead zirconate titanate (Pb(Zr,Ti)O ₃ ) (hereinafter also referred to as PZT) which has good piezoelectricity and strong dielectric properties. The piezoelectric film is applied to memory devices such as non-volatile memory (FeRAM), inkjet heads, acceleration sensors and other MEMS (Micro Electro Mechanical Systems) technologies.

In recent years, a technique has been studied in which a Pt film oriented toward (200) is formed on a Si substrate oriented toward (100) via a _ZrO2 film oriented toward (200), thereby forming a piezoelectric film having good piezoelectric properties on the Pt film (Patent Document 1). However, during film formation or when used as a piezoelectric element, cracks or breakage may occur in the crystalline substrate due to bending stress, and durability or long-term use cannot be fully satisfied, and a piezoelectric element that can withstand bending stress is desired.

(Prior technical literature) (Patent Literature)

Patent document 1: Japanese Patent Publication No. 2015-154015

The purpose of the present invention is to provide a laminated structure, element, electronic device, electronic machine and system with good bending strength.

In order to achieve the above purpose, the inventors of the present invention have conducted careful research and have successfully laminated a metal film composed of metal transformed from a mathematic bulk oriented in the (100) direction on a crystalline substrate oriented in the (100) direction. It is also known that when a piezoelectric film is formed on the crystalline substrate after the above lamination, a piezoelectric element with good bending strength can be realized. It is also found that such an element can completely solve the above known problems.

Furthermore, the present invention was completed after further repeated research after obtaining the above insights.

That is, the present invention relates to the following invention.

[1] A layered structure having at least a first layer and a second layer layered on a crystalline substrate,

The aforementioned first layer is composed of a metal compound film.

The second layer is composed of a metal film of a metal that undergoes Martensitic transformation due to heat treatment or processing, and the crystalline substrate, the first layer, and the second layer are oriented in substantially the same crystal axis direction.

[2] The layered structure as described in [1] above, wherein the metal comprises Fe.

[3] The layered structure as described in [1] or [2] above, wherein the metal contains Cr.

[4] A layered structure as described in any one of [1] to [3] above, wherein the metal comprises Ni.

[5] A layered structure as described in any one of [1] to [4] above, wherein the metal comprises Fe and Cr.

[6] A layered structure as described in any one of [1] to [5] above, wherein the metal is stainless steel.

[7] A multilayer structure as described in any one of [1] to [6] above, wherein the thickness of the metal film is less than 100 μm.

[8] A multilayer structure as described in any one of [1] to [7] above, wherein the thickness of the metal film is 1 μm to 10 μm.

[9] A layered structure as described in any one of [1] to [8] above, wherein the metal compound film contains Hf and/or Zr.

[10] A multilayer structure as described in any one of [1] to [9] above, wherein the metal compound film is composed of an oxide or nitride containing Hf and/or Zr.

[11] A layered structure as described in any one of [1] to [10] above, wherein the crystal axis direction is the (100) direction.

[12] A multilayer structure as described in any one of [1] to [11] above, wherein the crystal substrate is a Si substrate.

[13] A multilayer structure as described in any one of [1] to [12] above, wherein a piezoelectric layer or a semiconductor layer is stacked on the second layer via a third layer and a fourth layer, the third layer is made of a metal different from the metal, and the fourth layer is made of a conductive metal oxide.

[14] The layered structure described in [13] above, wherein the third layer comprises a metal belonging to Group 10 or Group 11 of the Periodic Table of Elements.

[15] The layered structure as described in [13] or [14] above, wherein the conductive metal oxide contains Sr and/or Ru.

[16] A layered structure as described in any one of [13] to [15] above, wherein the piezoelectric layer is layered, and the piezoelectric layer contains Pb and Ti.

[17] A component comprising a layered structure, wherein the layered structure is a layered structure as described in any one of [1] to [16].

[18] The element as described in [17] above, which is a piezoelectric element or a semiconductor element.

[19] An electronic device comprising a component, wherein the component is the component described in [17] or [18] above.

[20] An electronic machine comprising an electronic device, wherein the electronic device is the electronic device described in [19].

[21] A system comprising an electronic machine, wherein the electronic machine is the electronic machine described in [20].

The multilayer structure, element, electronic device, electronic machine and system of the present invention have good bending strength.

1: Crystalline substrate (Si substrate)

2: HfZrN film

3: SUS film (FeCrNi film)

4: Pt film

5:SRO membrane

6: Piezoelectric layer (PbTiO film)

21: Crystalline substrate (Si substrate)

23:SUS film

24a:Pt film

24b:Pt film

24c:Pt film

25a:SRO membrane

25b:SRO membrane

25c:SRO membrane

25d:SRO membrane

26a: PZT film

26b: PZT film

28A: Cantilever beam

28B: Cantilever beam

29: Gap

30: Hollow

31: Crystalline substrate (Si substrate)

32: HfZrN film

33:SUS film

34a:Pt film

34b:Pt film

35a:SRO membrane

35b:SRO membrane

36: PZT film

37: Insulation film

38: Conductive pad

39: Conductive path

40: Flow path

41: Chamber

42: Passivation layer

1101a to 101b: Metal source

1102a to 102j: Grounding

1103a to 103b: ICP electrode

1104a to 104b: Cutoff filter

1105a to 105b: DC power supply

1106a to 106b: RF power supply

1107a to 107b: Lights

1108: Ar source

1109: Reactive gas source

1110: Power supply

1111: Substrate holder

1112: Substrate

1113:Cutoff filter

1114:ICP Ring

1115: Vacuum tank

1116: Rotation axis

FIG1 is a diagram schematically showing an example of a preferred embodiment of the layered structure of the present invention.

FIG2 is a diagram showing the XRD diffraction pattern of the embodiment.

Figure 3 is a diagram illustrating a test piece of an example product of a test example.

Figure 4 is a diagram illustrating a test piece of a comparative product of a test example.

Figure 5 is a graph showing the bending strength test results of the test example.

FIG6 is a diagram schematically showing a preferred example of the implementation of the MEMS transducer in the present invention.

FIG. 7 schematically shows an example of a cross-sectional view of a portion of a wafer having a piezoelectric actuator as an application example of the present invention applicable to a fluid discharge device.

FIG8 is a diagram schematically showing a film forming device applicable to the embodiment.

The laminated structure of the present invention is characterized in that at least a first layer and a second layer are laminated on a crystalline substrate, the first layer is composed of a metal compound film, the second layer is composed of a metal film of a metal that is transformed from a bulk metal by heat treatment or processing, and the crystalline substrate, the first layer, and the second layer are oriented in substantially the same crystal axis direction. Furthermore, the crystal axis direction is not particularly limited, but is preferably (100) or (111), and more preferably (100).

The metal is not particularly limited as long as it is a metal that can be transformed into a bulk material by heat treatment or processing, and may be a known metal. The metal is usually contained in the metal film as a main component. As for the metals transformed from the aforementioned Matan bulk, for example, there can be listed Fe-Cr-Ni, Fe, Fe-Ni, Fe-Ni-Co, Fe-Si, Fe-Cr, Fe-Mn, Fe-Mn-C, Fe-Mn-Ni, Fe-Mn-Cr, Fe-C, Fe-N, Fe-Ni-C, Fe-Cr-C, Fe-Cu-C, Fe-Si-C, Fe-Cr-Ni-C, Co, Co-Ni, Co-Fe, Mn-Cu, In-Tl, In-Tl-Li, Na, Zr, Tl, Hf, Ti, Ti-Al, Ti-Cu, Ti-Cr, Ti-Fe, Ti-Mn, Ti-Mo, Ti-V, Ti-Zr, Ti-Al-V, Zr-U, Cu-Al-Ni, Cu-Al, Ag-Cd, Au-Cd, Au-Cd-Cu, Li, Li-Mg, Cu-Zn, U, U-Cr, Hg, etc. In the present invention, the aforementioned metal is preferably Fe, Cr or Ni, more preferably Fe and Cr, and even more preferably stainless steel. According to the preferred range, the bending strength can be made better. In addition, the "main component" is as long as the atomic ratio of the aforementioned metal in the aforementioned metal film is 0.5 or more. In the present invention, the atomic ratio of the aforementioned metal relative to all metal elements in the aforementioned metal film is preferably 0.7 or more, and more preferably 0.8 or more.

Furthermore, in the present invention, the aforementioned metal film is preferably oriented toward the (100) direction. The aforementioned "oriented toward the (100) direction" means that the crystal azimuth angle detected by the X-ray diffraction method is oriented toward the (100) direction. More specifically, as long as the peak ratio of the (100) direction relative to the total peak value of the aforementioned metal film detected by the X-ray diffraction method is 50% or more, the aforementioned peak ratio is preferably 90% or more.

In the present invention, the thickness of the aforementioned metal film is preferably less than 100μm, and more preferably 1μm to 10μm. According to the preferred range, it is better for the intermediate film used for crystal growth of functional film.

The aforementioned metal film is crystallized in the (100) direction on the substrate such as a Si substrate, and a metal compound film containing Hf and/or Zr is formed into a first layer by crystal growth, and then the aforementioned metal film is formed into a second layer by crystal growth, and can be easily obtained. This is a new insight obtained by the inventors of the present invention. The aforementioned metal compound film is preferably an oxide or nitride containing Hf and/or Zr, and more preferably a nitride containing Hf and/or Zr.

The aforementioned crystallized substrate (hereinafter also referred to as "substrate") is not particularly limited in terms of the substrate material, etc., as long as it does not hinder the purpose of the present invention, and can be a known crystallized substrate. It can be an organic compound or an inorganic compound. In the present invention, the aforementioned crystallized substrate preferably contains an inorganic compound. In the present invention, the aforementioned substrate is preferably a substrate having crystals on a part or all of the surface, more preferably a crystallized substrate having crystals on all or a part of the main surface of the crystal growth side, and even more preferably a crystallized substrate having crystals on the entire main surface of the crystal growth side. The aforementioned crystal is not particularly limited as long as it does not hinder the purpose of the present invention, and the crystal structure is not particularly limited either, but preferably is a cubic, tetragonal, trigonal, hexagonal, orthorhombic or monoclinic crystal, and more preferably is a crystal oriented toward (100) or (200). In addition, the aforementioned crystal substrate may also have a bias angle, and as for the aforementioned bias angle, for example, a bias angle of 0.2° to 12.0° can be listed. Here, "bias angle" refers to the angle between the substrate surface and the crystal growth plane. The shape of the aforementioned substrate is not particularly limited as long as it is plate-shaped and serves as a support for the aforementioned epitaxial film. It can be an insulating substrate or a semiconductor substrate, but in the present invention, the aforementioned substrate is preferably a Si substrate, more preferably a crystalline Si substrate, and most preferably a crystalline Si substrate oriented toward (100). In addition, as for the aforementioned substrate material, in addition to the Si substrate, for example, one or more metals belonging to Group 3 to Group 15 of the periodic table of elements or oxides of such metals can be listed. The shape of the aforementioned substrate is not particularly limited, and can be roughly circular (e.g., circular, elliptical, etc.), or polygonal (e.g., triangle, square, rectangle, pentagon, hexagon, heptagon, octagon, pentagon, etc.), and various shapes can be appropriately adopted. Furthermore, in the present invention, a large-area substrate can also be adopted. By adopting such a large-area substrate, the area of the epitaxial film can be increased.

Furthermore, in the present invention, although the aforementioned crystal substrate preferably has a flat surface, it is also desirable that the aforementioned crystal substrate has a concavo-convex shape on a part or all of the surface, which can also be used as a method of improving the quality of the crystal growth of the aforementioned epitaxial film. The crystal substrate having the aforementioned concavo-convex shape can be formed with a concavo-convex portion composed of concave portions or convex portions on a part or all of the surface, and the aforementioned concavo-convex portion can be formed with a convex portion or a concave portion without any particular limitation, and can be a concavo-convex portion composed of a convex portion, a concavo-convex portion composed of a concave portion, or a concavo-convex portion composed of a convex portion and a concave portion. Furthermore, the aforementioned concavo-convex portion can be formed by regular convex portions or concave portions, or by irregular convex portions or concave portions. In the present invention, the concavo-convex part is preferably formed periodically, and more preferably is periodically and regularly patterned. As for the shape of the concavo-convex part, although there is no particular limitation, it can be, for example, stripe-shaped, dot-shaped, mesh-shaped or irregular, etc. In the present invention, it is preferably dot-shaped or stripe-shaped, and more preferably dot-shaped. Furthermore, when the concavo-convex part is periodically and regularly patterned, the pattern shape of the concavo-convex part is preferably a triangle, a quadrangle (such as a square, a rectangle or a trapezoid, etc.), a polygon such as a pentagon or a hexagon, a circle, an ellipse, etc. In addition, when the concave-convex part is formed into a dot shape, it is preferred to make the lattice shape of the dot into a lattice shape such as a square lattice, a rhombus lattice, a triangular lattice, a hexagonal lattice, etc., and it is more preferred to make it into a lattice shape of a triangular lattice. As for the cross-sectional shape of the concave part or the convex part of the aforementioned concave-convex part, although there is no special limitation, for example, a U-shaped, a U-shaped, an inverse U-shaped, a wave-shaped, or a triangle, a quadrangle (such as a square, a rectangle or a trapezoid, etc.), a pentagon or a hexagon, etc. polygon, etc. can be listed. In addition, although the thickness of the aforementioned crystalline substrate is not particularly limited, it is preferably 50 to 2000μm, and more preferably 100 to 1000μm.

The aforementioned piezoelectric layer is not particularly limited as long as it is a piezoelectric layer composed of a piezoelectric. The aforementioned piezoelectric may be a known piezoelectric, but in the present invention, the aforementioned piezoelectric preferably contains Pb and Ti. Furthermore, the aforementioned semiconductor layer is not particularly limited as long as it is a semiconductor layer composed of a semiconductor. The aforementioned semiconductor may be a known semiconductor, but in the present invention, the aforementioned semiconductor preferably contains Si, SiC, GaN or Ga ₂ O _3. In addition, in this specification, the terms "film" and "layer" may be replaced with each other according to circumstances or conditions.

Furthermore, in the present invention, the piezoelectric layer or the semiconductor layer is preferably stacked on the second layer via the third layer and the fourth layer. The third layer is preferably made of a metal different from the metal, and the fourth layer is preferably made of a conductive metal oxide. As for the metal of the third layer, for example, gold, silver, platinum, palladium, silver-palladium, copper, nickel, or alloys thereof can be listed, but in the present invention, it is preferably a metal belonging to Group 10 or Group 11 of the Periodic Table of Elements, and more preferably platinum.

The aforementioned conductive metal oxide is not particularly limited as long as it does not hinder the purpose of the present invention, and can be a known conductive metal oxide. However, in the present invention, it is preferably a SRO film containing Sr and/or Ru, and more preferably a Sr and Ru film.

The aforementioned first layer, second layer, third layer and fourth layer can all be deposited using known film-forming methods. In the present invention, the aforementioned film-forming method is preferably evaporation (including MBE) or sputtering. The thickness of each layer is not particularly limited, but is preferably 10nm to 100μm, and more preferably 50nm to 30μm.

The metal film or multilayer structure obtained as described above is suitable for use in piezoelectric elements or semiconductor elements and other elements by known means. Furthermore, the aforementioned elements are suitable for use in electronic devices according to general methods. For example, by connecting the aforementioned multilayer structure as a piezoelectric element to a power source or an electric/electronic circuit, and installing or packaging it on a circuit substrate, a variety of electronic devices can be constructed. In the present invention, the aforementioned electronic device is preferably a piezoelectric device, for example, it can be used as a piezoelectric device in electronic machines such as inkjet printer heads, microactuators, gyroscopes, motion sensors, etc. Furthermore, if it is connected to an amplifier and a rectifier circuit and packaged, it can be used in various sensors such as magnetic sensors. Furthermore, it can also be applied to constant voltage driven memory. For example, if the storage element is connected to the rectifying power management circuit, it can become an energy conversion device (energy collector) that generates electricity from an external magnetic field or vibration. In addition, the aforementioned energy conversion device is preferably assembled in a power supply system or wearable terminal (earphones/ear-worn devices, smart watches, smart glasses (glasses), smart contact lenses, artificial inner ears, heart rate regulators, etc.). In the present invention, it is preferred to use the aforementioned multilayer structure in, for example, smart glasses, AR head-mounted devices, MEMS mirrors suitable for LiDAR systems, piezoelectric MEMS ultrasonic transducers (PMUTs) suitable for cutting-edge medical treatment, and piezoelectric element heads suitable for commercial and industrial 3D printers.

The aforementioned electronic device is applied to electronic equipment according to a general method. As for the aforementioned electronic equipment, in addition to the aforementioned electronic equipment, it can also be applied to various electronic equipment. More specifically, as preferred examples, liquid dispensing heads, liquid dispensing devices, vibration motors, optical equipment, vibration devices, camera equipment, piezoelectric audio parts or sound players with the piezoelectric audio parts, sound recorders, mobile phones, various information terminals, etc. can be cited.

Furthermore, the aforementioned electronic machines are also applicable to systems according to general methods. For example, sensor systems can be cited as examples of such systems.

[Implementation example]

(Example 1) The crystal growth side of the Si substrate (100) is treated by RIE, and in the presence of nitrogen, the metal of the evaporation source is thermally reacted with nitrogen by evaporation to form a HfZrN single crystal on the Si substrate. In addition, the conditions of the evaporation method during the film formation are as follows.

Evaporation source: Hf, Zr

Voltage: 3.5 to 4.75V

Pressure: 3×10 ^-2 to 6×10 ^-2 Pa

Substrate temperature: 450 to 700°C

FIG8 shows an evaporation film forming apparatus used in the evaporation of a HfZrN single crystal. The film forming apparatus of FIG8 is a crucible having at least: metal sources 1101a to 1101b, grounds 1102a to 1102h, ICP electrodes 1103a to 1103b, cutoff filters 1104a to 1104b, DC power sources 1105a to 1105b, RF power sources 1106a to 1106b, lamps 1107a to 1107b, Ar sources 1108, reactive gas sources 1109, power sources 1110, substrate holders 1111, substrates 1112, cutoff filters 1113, ICP rings 1114, vacuum chambers 1115, and rotating shafts 1116. In addition, the ICP electrodes 1103a to 1103b in FIG8 have a curved, generally concave shape or a parabolic shape on the center side of the substrate 1112.

As shown in FIG8 , the substrate 1112 is locked on the substrate holder 1111. Then, the power supply 1110 and the rotating mechanism (not shown) are used to rotate the rotating shaft 1116, thereby rotating the substrate 1112. In addition, the substrate 112 is heated by the lamps 1107a and 1107b, and the vacuum chamber 1115 is evacuated or depressurized by exhausting gas by a vacuum pump (not shown). Then, Ar gas is introduced into the vacuum chamber 1115 from the Ar source 1108, and Ar plasma is formed on the substrate 1112 using the DC power supplies 1105a to 1105b, the RF power supplies 1106a to 1106b, the ICP electrodes 1103a to 1103b, the cutoff filters 1104a to 1104b, and the grounding 1102a to 1102h to clean the surface of the substrate 1112.

Ar gas is introduced into the vacuum chamber 1115, and reactive gas is introduced using the reactive gas source 1109. At this time, the lamps 1107a to 1107b belonging to the heating lamps are turned on and off alternately and repeatedly, so that a better quality crystal growth film can be formed.

Next, a SUS304 single crystal film was formed in the same manner as above, except that Fe, Cr, and Ni were used as the evaporation source metals.

Next, a platinum (Pt) metal film is formed as a conductive film on the single crystal film of the crystalline metal oxide by sputtering. The conditions at this time are as follows.

Equipment: ULVAC sputtering equipment QAM-4

Pressure: 1.20×10 ^-1 Pa

Subject: Pt

Power: 100W (DC)

Thickness: 100nm

Substrate temperature: 450 to 600°C

Next, an SRO film is formed on the conductive film by sputtering. The conditions at this time are as follows.

Equipment: ULVAC sputtering equipment QAM-4

Power: 150W (RF)

Gas: Ar

Pressure: 1.8Pa

Substrate temperature: 600℃

Thickness: 20nm

Next, a PbTiO ₃ film is formed on the SRO film as a piezoelectric film. The resulting multilayer structure has good adhesion and crystallinity. In addition, an X-ray diffraction device is used to measure the crystallinity of the crystalline substrate of the multilayer structure, the single crystal film of the crystalline metal oxide, and the conductive film. Figure 2 shows the XRD measurement results. As shown in Figure 2, a SUS304 single crystal film with good crystallinity is formed, and the crystallinity of the PbTiO ₃ film is also good.

(Test example)

In the test example, a cantilever of a micro-component as shown in FIG3 and FIG4 was made using FIB FB2100 (manufactured by Hitachi High-Technologies). When the destructive strength characteristics were evaluated using the nano-indenter NanoTest Xtreme (manufactured by Micro Materials), the result was as shown in FIG5 . FIG5 shows that the destructive strength of Si is a roughly constant value of about 1 GPa. Considering that the bending strength of Si single crystal bulk material is about 300 MPa (thesis), it can be seen that micron materials have greater strength. Furthermore, in the case of SUS304 single crystal film, it has a destructive strength of about 5 GPa, which is about 5 times the bending strength of Si single crystal. This is because by using SUS304 single crystal thin film in the beam of MEMS devices (equivalent to the movable part, the active layer of the SOI substrate), in addition to a significant improvement in the displacement of the MEMS device, a significant improvement in the life characteristics can also be expected.

(Application examples)

The following diagrams are used to specifically describe the application examples of the obtained multilayer structure, but the present invention is not limited to such application examples. In addition, in the present invention, unless otherwise specified, piezoelectric devices can be manufactured from the aforementioned multilayer structure by known means.

FIG6 shows an implementation of an audio MEMS transducer for a MEMS microphone using the aforementioned multilayer structure in the present invention. In addition, the aforementioned MEMS transducer can be used to construct an audio output device (such as a speaker, etc.).

The MEMS microphone formed by the acoustic MEMS transducer of FIG. 6 is a cantilever type MEMS microphone, and has a Si substrate 21 having two cantilever beams 28A, 28B and a cavity 30. Each cantilever beam 28A, 28B is fixed to the substrate 21 at its end, and a gap 29 is provided between the cantilever beams 8A, 8B. In addition, the cantilever beams 8A, 8B are formed of a laminated structure including, for example, a plurality of piezoelectric layers (PZT films) 26a, 26b, and overlapped with a plurality of electrode layers, namely, Pt films 24a, 24b, 24c and SRO films 25a, 25b, 25c, 25d. The Pt film 24a is provided on the SUS film 23, and the HfZrN film 23 is provided on the SUS film 23. Compared with the case of using _SiO2 or SiN, when the HfZrN film 23 is used, the adhesion and crystallinity with the Si substrate are better, and the crystallinity can be further improved by crossing multiple layers on the HfZrN film, and the piezoelectric characteristics and/or durability are also better.

FIG. 7 shows an application example in which the aforementioned multilayer structure in the present invention is suitable for printing purposes, especially in an application example of a fluid discharge device that can be used in the form of an inkjet head. Specifically, it shows a cross-sectional view of a portion of a wafer having a piezoelectric actuator, and the piezoelectric actuator includes Pt films 34a, 34b and SRO films 35a, 35b as electrode layers, and includes a PZT film 36 as a piezoelectric film. In addition to the aforementioned piezoelectric actuator, the wafer of FIG. 7 also has a chamber 41 for accommodating a fluid. The chamber 41 is configured to introduce a fluid from a groove (not shown) through a flow path 40. In addition, the wafer of FIG. 7 includes a Si substrate 31, and a HfZrN film 32 and a SUS film 33 are layered on the Si substrate 31 and face the chamber 41. In FIG. 7 , by using the HfZrN film 32, compared with the case of using SiO ₂ or SiN, the adhesion and crystallinity with the Si substrate are better, and multiple layers can be formed across the HfZrN film to further improve the crystallinity, and further the piezoelectric characteristics and/or durability are better. In addition, the HfZrN film 32 has a quadrangular shape in, for example, a top view (not shown), and the shape may be any of, for example, a square, a rectangle, a rectangle with rounded corners, a parallelogram, and the like.

On the SUS film 33, a Pt film 34a, an SRO film 35a, a piezoelectric film (PZT film) 36, an SRO film 35b, and a Pt film 34b are sequentially stacked to form a piezoelectric actuator. In addition, the piezoelectric actuator further comprises electrodes 34a and 35a, a piezoelectric film 36, and an insulating film 37 extending on the electrodes 34b and _35b . The insulating film 37 includes a dielectric material used for electrical insulation, and the dielectric material may be a known dielectric material, such as a _SiO2 layer, a SiN layer, or an _Al2O3 layer. In addition, the thickness of the insulating layer including the insulating film as a constituent material is not particularly limited, but is preferably between about 10 nm and about 10 μm. In addition, the conductive path 39 is provided on the insulating layer (insulating film) 37, and is in contact with the electrodes 34a and 35a, and the electrodes 34b and 35b, respectively, and can be selectively accessed when used. In addition, the constituent material of the conductive path can be a known conductive material, and as for such a conductive material, aluminum (Al) can be cited as an appropriate example. In addition, the passivation layer 42 is provided on the insulating layer 37, the electrodes 34b and 35b, and the conductive path 39. The passivation layer 42 only needs to be composed of a passivated dielectric material used for the aforementioned piezoelectric actuator. The dielectric material is not particularly limited and can be a known dielectric material. As for the aforementioned dielectric material, SiN or SION (silicon oxynitride) can be cited as appropriate examples. The thickness of the aforementioned passivation layer is not particularly limited, but is preferably between about 0.1μm and about 3μm. The conductive pad 38 is also similarly arranged along the aforementioned piezoelectric actuator and is electrically connected to the conductive path 39. In addition, the passivation layer 42 functions as a barrier layer to protect the piezoelectric body from being affected by humidity and the like.

(Industrial availability)

The metal film and multilayer structure of the present invention are suitable for use as electronic devices such as piezoelectric devices, and are suitable for use in electronic machines or sensor systems, etc.

1: Crystalline substrate (Si substrate)

2: HfZrN film

3: SUS film (FeCrNi film)

4: Pt film

5:SRO membrane

6: Piezoelectric layer (PbTiO film)

Claims (21)

A layered structure having at least a first layer and a second layer layered on a crystalline substrate, The aforementioned first layer is composed of a metal compound film. The aforementioned second layer is composed of a metal film of metal that has been transformed from bulk metal by heat treatment or processing. Furthermore, the aforementioned crystalline substrate, the aforementioned first layer, and the aforementioned second layer are oriented in substantially the same crystal axis direction. The layered structure as described in claim 1, wherein the metal includes Fe. The layered structure as described in claim 1 or 2, wherein the metal includes Cr. A layered structure as described in any one of claims 1 to 3, wherein the metal comprises Ni. A layered structure as described in any one of claims 1 to 4, wherein the metal comprises Fe and Cr. A layered structure as described in any one of claims 1 to 5, wherein the aforementioned metal is stainless steel. A multilayer structure as described in any one of claims 1 to 6, wherein the thickness of the metal film is less than 100 μm. A multilayer structure as described in any one of claims 1 to 7, wherein the thickness of the metal film is 1 μm to 10 μm. A layered structure as described in any one of claims 1 to 8, wherein the metal compound film contains Hf and/or Zr. A multilayer structure as described in any one of claims 1 to 9, wherein the metal compound film is composed of an oxide or nitride containing Hf and/or Zr. A layered structure as described in any one of claims 1 to 10, wherein the crystal axis direction is the (100) direction. A multilayer structure as described in any one of claims 1 to 11, wherein the aforementioned crystal substrate is a Si substrate. A multilayer structure as described in any one of claims 1 to 12, wherein a piezoelectric layer or a semiconductor layer is stacked on the second layer via a third layer and a fourth layer, the third layer is composed of a metal different from the metal, and the fourth layer is composed of a conductive metal oxide. The layered structure as described in claim 13, wherein the third layer comprises a metal belonging to Group 10 or Group 11 of the Periodic Table of Elements. The layered structure as described in claim 13 or 14, wherein the conductive metal oxide contains Sr and/or Ru. A laminated structure as described in any one of claims 13 to 15, wherein the aforementioned piezoelectric layer is laminated, and the aforementioned piezoelectric layer contains Pb and Ti. A component comprising a layered structure, wherein the layered structure is a layered structure as described in any one of claims 1 to 16. The element as described in claim 17 is a piezoelectric element or a semiconductor element. An electronic device comprising a component, wherein the component is a component described in claim 17 or 18. An electronic machine comprising an electronic device, wherein the electronic device is the electronic device described in claim 19. A system comprising an electronic machine, wherein the electronic machine is the electronic machine described in claim 20.

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