Classifications

• • C—CHEMISTRY; METALLURGY
  • C23—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; CHEMICAL SURFACE TREATMENT; DIFFUSION TREATMENT OF METALLIC MATERIAL; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL; INHIBITING CORROSION OF METALLIC MATERIAL OR INCRUSTATION IN GENERAL
  • C23C—COATING METALLIC MATERIAL; COATING MATERIAL WITH METALLIC MATERIAL; SURFACE TREATMENT OF METALLIC MATERIAL BY DIFFUSION INTO THE SURFACE, BY CHEMICAL CONVERSION OR SUBSTITUTION; COATING BY VACUUM EVAPORATION, BY SPUTTERING, BY ION IMPLANTATION OR BY CHEMICAL VAPOUR DEPOSITION, IN GENERAL
  • C23C14/00—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material
  • C23C14/06—Coating by vacuum evaporation, by sputtering or by ion implantation of the coating forming material characterised by the coating material
  • C23C14/08—Oxides
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N30/00—Piezoelectric or electrostrictive devices
  • H10N30/01—Manufacture or treatment
  • H10N30/04—Treatments to modify a piezoelectric or electrostrictive property, e.g. polarisation characteristics, vibration characteristics or mode tuning
  • H10N30/045—Treatments to modify a piezoelectric or electrostrictive property, e.g. polarisation characteristics, vibration characteristics or mode tuning by polarising
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N30/00—Piezoelectric or electrostrictive devices
  • H10N30/01—Manufacture or treatment
  • H10N30/06—Forming electrodes or interconnections, e.g. leads or terminals
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N30/00—Piezoelectric or electrostrictive devices
  • H10N30/01—Manufacture or treatment
  • H10N30/07—Forming of piezoelectric or electrostrictive parts or bodies on an electrical element or another base
  • H10N30/074—Forming of piezoelectric or electrostrictive parts or bodies on an electrical element or another base by depositing piezoelectric or electrostrictive layers, e.g. aerosol or screen printing
  • H10N30/076—Forming of piezoelectric or electrostrictive parts or bodies on an electrical element or another base by depositing piezoelectric or electrostrictive layers, e.g. aerosol or screen printing by vapour phase deposition
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N30/00—Piezoelectric or electrostrictive devices
  • H10N30/01—Manufacture or treatment
  • H10N30/07—Forming of piezoelectric or electrostrictive parts or bodies on an electrical element or another base
  • H10N30/074—Forming of piezoelectric or electrostrictive parts or bodies on an electrical element or another base by depositing piezoelectric or electrostrictive layers, e.g. aerosol or screen printing
  • H10N30/079—Forming of piezoelectric or electrostrictive parts or bodies on an electrical element or another base by depositing piezoelectric or electrostrictive layers, e.g. aerosol or screen printing using intermediate layers, e.g. for growth control
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N30/00—Piezoelectric or electrostrictive devices
  • H10N30/80—Constructional details
  • H10N30/85—Piezoelectric or electrostrictive active materials
  • H10N30/853—Ceramic compositions
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N—ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10N30/00—Piezoelectric or electrostrictive devices
  • H10N30/80—Constructional details
  • H10N30/87—Electrodes or interconnections, e.g. leads or terminals

Definitions

• the present invention relates to a piezoelectric body, a laminated structure, an electronic device, an electronic device, and a manufacturing method thereof.
• PZT lead zirconate titanate
• FeRAM nonvolatile memory
• the center of the hysteresis of the amount of polarization with respect to the applied voltage is shifted to the positive applied voltage side, and the remanent polarization Pr + at the applied voltage of 0 V is 20 ⁇ C/cm 2 or more, which is highly reliable and has excellent hysteresis. Measures have been awaited to improve the piezoelectric properties of piezoelectric films.
• An object of the present invention is to provide a piezoelectric body having excellent hysteresis characteristics, a laminated structure including the piezoelectric body, an electronic device, an electronic device, and a manufacturing method that can industrially advantageously obtain these.
• the present inventors formed at least a compound film on a crystal substrate, then laminated an epitaxial film containing a crystalline compound, and further deposited the film directly or on the epitaxial film. After laminating a single crystal film made of a conductive metal through another layer, when laminating a piezoelectric film directly or through another layer on the single crystal film, the epitaxial film is laminated.
• the epitaxial film is formed using the compound element in the compound film, and the piezoelectric film is laminated by vapor deposition or sputtering, so that the center of the hysteresis of the polarization amount with respect to the applied voltage is
• the piezoelectric film is laminated by vapor deposition or sputtering, so that the center of the hysteresis of the polarization amount with respect to the applied voltage is
• a piezoelectric material characterized in that the center of hysteresis of the amount of polarization with respect to applied voltage is shifted to the positive applied voltage side, and the residual polarization Pr + at the applied voltage of 0 V is 20 ⁇ C/cm 2 or more.
• [6] Forming at least a compound film on a crystal substrate, then laminating an epitaxial film containing a crystalline compound, and then depositing a single crystal made of a conductive metal directly or through another layer on the epitaxial film.
• a method for producing a laminated structure in which a piezoelectric film is laminated directly or through another layer on the single crystal film after laminating films comprising: laminating the epitaxial film on the single crystal film, and then laminating the piezoelectric film on the single crystal film, the method comprising: A method for manufacturing a laminated structure, characterized in that the epitaxial film is formed using an element, and the piezoelectric film is laminated by sputtering.
• a laminated structure including at least a crystal substrate, an epitaxial film containing a crystalline compound, an electrode, and a piezoelectric body, wherein the piezoelectric body is the piezoelectric body according to any one of [1] to [5] above.
• a laminated structure, wherein the epitaxial film is formed by incorporating a compound element in a compound film laminated on the crystal substrate into the crystalline compound.
• [14] A method of manufacturing an electronic device using a laminated structure, characterized in that the laminated structure is the laminated structure described in [8] or [9] above.
• [17] A system including an electronic device, wherein the electronic device is the electronic device described in [15] above.
• the laminated structure according to [18] above which has a buried layer comprising: [20] between the crystal substrate and the epitaxial film, an amorphous thin film containing a constituent metal of the epitaxial film and/or the crystal substrate, and one or more of the amorphous thin films embedded in a part of the crystal substrate;
• the laminated structure, electronic device, and electronic equipment of the present invention include a piezoelectric body having excellent hysteresis characteristics, and according to the manufacturing method of the present invention, the piezoelectric body, the laminated structure, the electronic device, and the piezoelectric body have excellent hysteresis characteristics. This has the effect that electronic equipment can be obtained industrially advantageously.
• FIG. 1 is a diagram schematically showing an example of a preferred embodiment of a precursor for a laminated structure of the present invention. It is a figure which shows typically an example of another suitable embodiment of the laminated structure of this invention. It is a figure which shows typically an example of the oxide film formation process of the suitable manufacturing method of the laminated structure of this invention.
• FIG. 2 is a diagram schematically showing an example of an epitaxial film forming step of a preferred method for manufacturing a laminated structure of the present invention.
• a cross-sectional STEM image observed in an example is shown.
• a cross-sectional STEM image observed in an example is shown.
• a STEM image observed in an example is shown.
• FIG. 1 is a diagram schematically showing an example of a preferred embodiment of a precursor for a laminated structure of the present invention. It is a figure which shows typically an example of another suitable embodiment of the laminated structure of this invention. It is a figure which shows typically an example of the oxide film formation process of the suitable manufacturing method of the laminated structure of this
• FIG. 1 is a diagram schematically showing a preferred embodiment of a MEMS transducer in the present invention.
• FIG. 2 is a diagram schematically showing an example of a cross-sectional view of a part of a wafer including a piezoelectric actuator as a preferred application example of the present invention to a fluid ejection device. It is a figure showing the hysteresis curve measured in an example. The vertical axis shows the residual polarization, and the horizontal axis shows the applied voltage. It is a figure showing the XPS measurement result in an example. It is a figure showing the XPS measurement result in an example.
• 1 is a diagram schematically showing a film forming apparatus suitably used in Examples. A cross-sectional STEM image measured in an example is shown. A STEM image measured in an example is shown. A STEM image of a buried layer measured in an example is shown.
• the piezoelectric body of the present invention is characterized in that the center of the hysteresis of the amount of polarization with respect to the applied voltage is shifted to the positive applied voltage side, and the residual polarization Pr + at the applied voltage of 0 V is 20 ⁇ C/cm 2 or more. do.
• the center of the hysteresis of the amount of polarization with respect to the applied voltage is shifted to a range of 100 to 300 V, and the residual polarization Pr + at the applied voltage of 0 V is 75 ⁇ C/cm 2 It is preferably at least 95 ⁇ C/cm 2 , more preferably at least 95 ⁇ C/cm 2 .
• the residual polarizations Pr + and Pr - at the applied voltage of 0 V take substantially the same absolute value.
• “Substantially the same absolute values” means that the absolute values of the remanent polarizations Pr + and Pr - are completely the same, or the difference between them is within 5% (preferably within 1%). means.
• the absolute values of the residual polarizations Pr + and Pr - at the applied voltage of 0 V are each preferably 20 ⁇ C/cm 2 or more, more preferably 75 ⁇ C/cm 2 or more, and 95 ⁇ C/cm 2 or more. Most preferably it is greater than or equal to cm 2 .
• the piezoelectric body is formed by forming at least a compound film on a crystal substrate, then laminating an epitaxial film containing a crystalline compound, and then layering a conductive metal directly or through another layer on the epitaxial film. After laminating a single crystal film, when a piezoelectric film is laminated directly or through another layer on the single crystal film, the epitaxial film is laminated using the compound element in the compound film. It can be easily obtained by forming an epitaxial film and laminating the piezoelectric films by vapor deposition or sputtering.
• the crystalline compound is not particularly limited and may be a known crystalline compound, but in the present invention, it is preferable that the crystalline compound is a metal compound, and the metal of the metal compound is also a known metal. It's fine. Examples of the metal include D block metals in the periodic table.
• the metal compound may also be a known compound, and examples of the crystalline compound include oxides, nitrides, oxynitrides, sulfides, oxysulfides, borides, oxyborides, and carbides. , oxycarbide, boron carbide, boron nitride, boron sulfide, carbonitride, carbon sulfide, or carboride.
• the crystalline compound is preferably a crystalline oxide
• the compound film is preferably an oxide film
• the compound element is preferably oxygen.
• the crystalline compound is preferably a crystalline nitride
• the compound film is preferably a nitride film
• the compound element is preferably nitrogen.
• FIG. 1 shows a preferred example of the precursor of the laminated structure
• the precursor of the laminated structure of FIG. 1 has an epitaxial layer 3 laminated on a crystal substrate 1 using an oxide film 2.
• a second epitaxial layer 4 is laminated on the epitaxial layer 3.
• film and “layer” may be interchanged depending on the case or the situation.
• oxides are cited as preferred examples of the laminated structure, the present invention is not limited to these preferred examples, and the present invention is also suitable for various compounds such as nitrides. can be applied.
• the precursor forms an oxide film 2 of the crystal substrate 1 on the crystal substrate 1, and then, using oxygen in the oxide film 2, as shown in FIG. It can be easily manufactured by forming an epitaxial film 3 made of a crystalline oxide on a crystal substrate 1.
• the precursor may have the oxide film 2 on the crystal substrate 1, but when the epitaxial film 3 is formed, all the oxygen in the oxide film 2 is taken in and the oxide film 2 may have disappeared.
• the crystal substrate (hereinafter also simply referred to as “substrate”) is not particularly limited, such as the substrate material, as long as it does not impede the purpose of the present invention, and may be any known crystal substrate. It may be an organic compound or an inorganic compound. In the present invention, it is preferable that the crystal substrate contains an inorganic compound. In the present invention, it is preferable that the substrate has crystals on part or all of its surface, and it is preferable that the substrate has crystals on all or part of its main surface on the crystal growth side. More preferably, a crystal substrate having crystals on the entire main surface on the crystal growth side is most preferable.
• the crystal is not particularly limited as long as it does not impede the purpose of the present invention, and the crystal structure is also not particularly limited, but may be cubic, tetragonal, trigonal, hexagonal, orthorhombic, or monoclinic. It is preferable that the crystal be a crystal of a type, and a crystal oriented in (100) or (200) direction is more preferable. Further, the crystal substrate may have an off-angle, and examples of the off-angle include an off-angle of 0.2° to 12.0°. Here, the "off angle" refers to the angle between the substrate surface and the crystal growth plane.
• the shape of the substrate is not particularly limited as long as it is plate-like and serves as a support for the epitaxial film.
• the substrate is preferably a Si substrate, more preferably a crystalline Si substrate, and (100) Most preferably, it is a crystalline Si substrate oriented in the direction of .
• the substrate material include, in addition to the Si substrate, one or more metals belonging to Groups 3 to 15 of the periodic table, or oxides of these metals.
• the shape of the substrate is not particularly limited, and may be approximately circular (for example, circular, oval, etc.) or polygonal (for example, triangular, square, rectangular, pentagonal, hexagonal, heptagonal, etc.). , octagonal, nonagonal, etc.), and various shapes can be suitably used.
• a large-area substrate can be used, and by using such a large-area substrate, the area of the epitaxial film can be increased.
• the crystal substrate has a flat surface, but the quality of crystal growth of the epitaxial film may be improved if the crystal substrate has an uneven shape on part or all of the surface. This is preferable because it provides better results.
• the above-mentioned crystal substrate having an uneven shape may be used as long as an uneven part consisting of a recess or a convex part is formed on a part or all of the surface. It is not limited, and it may be an uneven part consisting of a convex part, an uneven part consisting of a concave part, or an uneven part consisting of a convex part and a concave part.
• the uneven portions may be formed from regular protrusions or recesses, or may be formed from irregular protrusions or recesses.
• the uneven portions are formed periodically, and more preferably that they are patterned periodically and regularly.
• the shape of the uneven portion is not particularly limited, and examples thereof include a stripe shape, a dot shape, a mesh shape, or a random shape, but in the present invention, a dot shape or a stripe shape is preferable, and a dot shape is more preferable. .
• the pattern shape of the uneven portions may be a polygonal shape such as a triangle, a quadrilateral (for example, a square, a rectangle, or a trapezoid), a pentagon, or a hexagon.
• the shape is circular or elliptical.
• the lattice shape of the dots is a lattice shape such as a square lattice, an orthorhombic lattice, a triangular lattice, a hexagonal lattice, etc., and a triangular lattice shape is used. is more preferable.
• the cross-sectional shape of the concave portion or convex portion of the uneven portion is not particularly limited, and includes, for example, a U-shape, a U-shape, an inverted U-shape, a wave shape, a triangle, a quadrilateral (for example, a square, a rectangle, a trapezoid, etc.). ), polygons such as pentagons and hexagons.
• the thickness of the crystal substrate is not particularly limited, but is preferably 50 to 2000 ⁇ m, more preferably 100 to 1000 ⁇ m.
• the oxide film is not particularly limited as long as it is an oxide film that can incorporate oxygen atoms into the epitaxial film, and usually contains an oxide material.
• the oxidizing material is not particularly limited as long as it does not impede the object of the present invention, and may be any known oxidizing material. Examples of the oxidizing material include metal or metalloid oxides.
• the oxide film contains the oxidizing material of the crystal substrate, and examples of such an oxide film include a thermal oxide film, a natural oxide film, and the like of the crystal substrate.
• the oxide film may be a sacrificial layer in which part or all of the film disappears or is destroyed when oxygen atoms are taken in; It is preferable that the oxide layer is an oxygen-supplying sacrificial layer in which oxygen atoms are taken in and the oxide film itself disappears during crystal growth. Further, the oxide film may be patterned, for example, in a stripe shape, a dot shape, a mesh shape, or a random shape. Note that the thickness of the oxide film is not particularly limited, but is preferably greater than 1 nm and less than 100 nm.
• the epitaxial layer is not particularly limited as long as it includes an epitaxial film in which oxygen atoms in the oxide film are incorporated.
• an epitaxial film in which oxygen atoms in the oxide film are incorporated means that oxygen atoms in the oxide film are taken away by the epitaxial film during crystal growth of the epitaxial film.
• the epitaxial film is not particularly limited as long as it is an epitaxial film that is crystal-grown by incorporating oxygen atoms in the oxide film, but preferably contains a metal or a metal oxide in the present invention.
• the metal preferably includes, for example, one or more metals belonging to the d block of the periodic table.
• the metal oxide preferably includes, for example, oxides of one or more metals belonging to the d block of the periodic table.
• the epitaxial film contains a dielectric. Further, in the present invention, it is preferable that the epitaxial film contains a neutron absorbing material.
• the neutron absorbing material may be a known neutron absorbing material, and in the present invention, such a neutron absorbing material is used to improve adhesion, crystallinity, and functionality by incorporating oxygen from the oxide film. The properties of the film can be improved.
• a suitable example of the neutron absorbing material is hafnium (Hf).
• the epitaxial layer may be composed of one or more types of epitaxial films, and in the present invention, it is preferable that the epitaxial layer includes two or more types of epitaxial films.
• a second epitaxial film having a composition different from that of the epitaxial film is laminated on the epitaxial film, either directly or via another layer.
• first epitaxial layer the interface between the epitaxial layer and the second epitaxial layer is formed at the interface between the epitaxial layer and the second epitaxial layer.
• the first epitaxial layer can be regularly transformed so that the lattice constant is substantially the same as the lattice constant of the second epitaxial layer.
• a suitable example of the above-mentioned regular transformation is a transformation in which the shape deforms into a peak-to-valley structure, and in the present invention, the angles formed by adjacent apexes and bottom points of the peak-to-valley structure are Preferably, they are different, and more preferably, the angles are each within a range of 30° to 45°.
• the epitaxial layer usually has a first crystal plane and a second crystal plane, but the transformation causes a difference in lattice constant between the first crystal plane and the second crystal plane. Therefore, it is preferable that the difference in lattice constant between the first crystal plane and the second crystal plane is within the range of 0.1% to 20%.
• the difference in lattice constant between the first epitaxial layer and the second epitaxial layer can be set to 0. A range of 1% to 20% can be easily achieved.
• the epitaxial film is a dielectric and the second epitaxial film is an electrode.
• the second epitaxial layer is made of a single crystal film of a conductive metal, a defect-free film with a large area can be easily obtained, and it not only functions as an electrode, but also functions as an electrode. It is also possible to improve the characteristics of the element and the like.
• the conductive metal is not particularly limited as long as it does not impede the purpose of the present invention, and examples thereof include gold, silver, platinum, palladium, silver palladium, copper, nickel, and alloys thereof. preferably contains platinum.
• a single crystal film can be easily obtained.
• a single crystal film having a thickness of preferably 100 nm or more can be easily obtained as an electrode.
• a third epitaxial film and/or a third epitaxial film having a composition different from that of the epitaxial film and the second epitaxial film is further provided on the second epitaxial film, either directly or through another layer.
• a fourth epitaxial film is laminated.
• FIG. 2 shows a preferred example of a laminated structure in which the third epitaxial layer 5 and the fourth epitaxial layer 6 are laminated on the second epitaxial layer 4.
• a first epitaxial layer 3 is laminated using an oxide film on a crystal substrate 1, and a second epitaxial layer 4 is further laminated on the first epitaxial layer 3.
• a third epitaxial layer 5 is laminated on the second epitaxial layer 4, and a fourth epitaxial layer 6 is laminated on the third epitaxial layer 5.
• the third epitaxial film in the third epitaxial layer is preferably a dielectric, a semiconductor, or a conductor, more preferably a dielectric, and most preferably a piezoelectric.
• the fourth epitaxial film in the fourth epitaxial layer is preferably a dielectric, a semiconductor, or a conductor, more preferably a dielectric, and most preferably a piezoelectric.
• the thickness of each of the epitaxial films is not particularly limited, but is preferably 10 nm to 1000 ⁇ m, more preferably 10 nm to 100 ⁇ m.
• the precursor When laminating an epitaxial layer on a crystal substrate via at least an oxide film, the precursor is used to form an epitaxial film using oxygen atoms in the oxide film at 350° C. to 700° C. It can be easily obtained by doing this. When the temperature is in the range of 350° C. to 700° C., oxygen atoms in the oxide film can be more easily incorporated into the epitaxial film to cause crystal growth.
• the epitaxial film using oxygen gas after forming the laminated layer using oxygen atoms in the oxide film. etc. will be better.
• a film in this manner a layered structure in which an epitaxial layer is stacked on a crystal substrate, wherein the epitaxial layer and/or the crystal substrate is provided between the crystal substrate and the epitaxial layer. It is possible to easily obtain a laminated structure having an amorphous thin film containing the constituent metals and/or one or more buried layers containing the constituent metals embedded in a part of the crystal substrate.
• the laminated structure has both the amorphous layer and the buried layer, since the functionality of the epitaxial film can be further improved. Further, it is preferable that the amorphous layer and the buried layer each contain a constituent metal of the epitaxial layer, since this results in better crystallinity of the epitaxial film and the like. Further, in the present invention, it is preferable that the constituent metal contains Hf, since this further promotes stress relaxation and further enables realization of stress relaxation in multiple stages.
• the thickness of the amorphous thin film is 1 nm to 10 nm because it can further improve the crystallinity of the epitaxial film, and the amorphous thin film having such a preferable thickness is preferably used in the present invention. can be easily obtained according to a preferred manufacturing method. Further, in the present invention, it is preferable that the buried layer has a substantially inverted triangular cross-sectional shape, since this can further improve the functionality of the epitaxial film. Note that these preferable laminated structures can be easily obtained by appropriately adjusting the thickness of the oxide film, the timing of introducing the oxygen gas, and the like.
• the epitaxial film forming means is usually suitably used, and the film forming means may be any known film forming means.
• the film forming means is preferably vapor deposition or sputtering, and more preferably vapor deposition.
• the laminating means used in laminating the third epitaxial film or the fourth epitaxial film is usually sputtering, and the sputtering may be non-high vacuum sputtering.
• the center of the hysteresis of the amount of polarization with respect to the applied voltage is shifted to the positive applied voltage side, and the piezoelectric material has a residual polarization Pr + of 20 ⁇ C/cm 2 or more at the applied voltage of 0 V. can be obtained more easily.
• the epitaxial film is such that oxygen atoms in the oxide film laminated on the crystal substrate are oxidized by the crystalline oxide.
• the present invention also includes a laminated structure that is incorporated into a product, and in the laminated structure of the present invention, the epitaxial film constitutes part or all of the buffer layer, and the crystal growth substrate is preferable.
• the laminated structure obtained as described above is suitably used for electronic devices according to a conventional method.
• various electronic devices can be constructed by connecting the laminated structure as a piezoelectric element to a power source or an electric/electronic circuit, mounting it on a circuit board, or packaging it.
• the electronic device is preferably a piezoelectric device, and can be used, for example, as a piezoelectric device in electronic equipment such as an inkjet printer head, a microactuator, a gyroscope, and a motion sensor.
• an amplifier and a rectifier circuit are connected and packaged, it can be used for various sensors such as magnetic sensors.
• the laminated structure can be used, for example, in smart glasses, AR headsets, MEMS mirrors for LiDAR systems, piezoelectric MEMS ultrasonic transducers (PMUT) for advanced medical applications, piezo heads for commercial and industrial 3D printers, etc. It is preferable to use
• the electronic device is suitably used in electronic equipment according to a conventional method.
• the electronic device can be applied to various electronic devices other than those described above, and more specifically includes, for example, a liquid ejection head, a liquid ejection device, a vibration wave motor, an optical device, a vibration device, an imaging device, Suitable examples include piezoelectric acoustic components and audio playback devices, audio recording devices, mobile phones, and various information terminals that include the piezoelectric acoustic components.
• the electronic device is also applied to a system according to a conventional method, and such a system includes, for example, a sensor system.
• Example 1 After treating the crystal growth side of the Si substrate (100) with RIE and heating it in the presence of oxygen to form a thermal oxide film, the metal of the evaporation source and the Si A single crystal of the crystalline metal oxide was formed on the Si substrate by causing a thermal reaction with oxygen in the oxide film on the substrate. Then, by flowing oxygen, lowering the temperature, and increasing the pressure, a single crystal film of a crystalline metal oxide was formed by a vapor deposition method. The conditions of the vapor deposition method during this film formation were as follows. Vapor deposition source: Hf, Zr Voltage: 3.5-4.75V Pressure: 3 ⁇ 10-2 to 6 ⁇ 10-2 Pa Substrate temperature: 450-700°C
• a metal film of platinum (Pt) was formed as a conductive film on the single crystal film of the crystalline metal oxide by sputtering.
• the conditions at this time are shown below.
• a Pb(Zr 0.52 Ti 0.48 )O 3 film is formed as a piezoelectric film on the SRO film by sputtering according to the above, adjusting conditions such as target, substrate temperature, and pressure. did.
• the relationship between the applied voltage and the residual polarization of the formed piezoelectric film was measured, and a hysteresis curve of the amount of polarization with respect to the applied voltage was obtained.
• the results are shown in FIG. As is clear from the hysteresis curve in FIG. 11, good hysteresis without imprints was obtained, and the obtained piezoelectric body shifted to the positive applied voltage side, and the residual polarization Pr + at the applied voltage of 0 V It was 20 ⁇ C/cm 2 or more.
• FIGS. 5 and 6 cross-sectional STEM images of the obtained laminated structure are shown in FIGS. 5 and 6. It can be seen from FIG. 6 that a very high quality laminated structure has been obtained. In particular, in FIG. It can be seen that the angles formed by the adjacent peaks and bottom points of the mountain-valley structure are different within the range of 30° to 45°. Further, X-ray crystal lattice images of the conductive film are shown in FIGS. 7 and 8. It can be seen from FIGS. 7 and 8 that defect-free, large-area conductive films exhibit good effects on the electrode properties and the piezoelectric properties of the piezoelectric film laminated thereon.
• FIG. 11 shows the XPS measurement results.
• a (Hf, Zr)O 2 film and a Pt single crystal film having good crystallinity were formed on the Si crystal substrate.
• Example 2 A platinum (Pt) metal film was formed as a conductive film on a single crystalline metal nitride film in the same manner as in Example 1, except that nitrogen gas was used instead of oxygen gas. Then, the crystal substrate of the laminated structure, the single crystal film of crystalline metal nitride, and the conductive film were each measured using an X-ray diffraction apparatus.
• FIG. 13 shows the XPS measurement results. As is clear from FIG. 13, a (Hf, Zr)N film and a Pt single crystal film having good crystallinity were formed on the Si crystal substrate. In addition, when measured by a four-terminal method, the obtained single crystal film of crystalline metal nitride had good conductivity.
• the vapor deposition film forming apparatus used in Example 1 is shown in FIG.
• the film forming apparatus of FIG. 14 includes metal sources 101a to 101b, earths 102a to 102h, ICP electrodes 103a to 103b, cut filters 104a to 104b, DC power supplies 105a to 105b, RF power supplies 106a to 106b, lamps 107a to 107b, It includes at least an Ar source 108, a reactive gas source 109, a power source 110, a substrate holder 111, a substrate 112, a cut filter 113, an ICP ring 114, a vacuum chamber 115, and a rotating shaft 116.
• the ICP electrodes 103a to 103b in FIG. 14 have a substantially concave curved shape or a parabolic shape curved toward the center of the substrate 112.
• the substrate 112 is locked onto the substrate holder 111.
• the rotating shaft 116 is rotated using the power source 110 and a rotating mechanism (not shown), and the substrate 112 is rotated.
• the substrate 112 is heated by lamps 107a to 107b, and the inside of the vacuum chamber 115 is evacuated to a vacuum or reduced pressure by a vacuum pump (not shown).
• Ar gas is introduced into the vacuum chamber 115 from the Ar source 108, and the substrate is The surface of the substrate 112 is cleaned by forming argon plasma on the substrate 112 .
• Ar gas is introduced into the vacuum chamber 115, and a reactive gas is also introduced using the reactive gas source 109.
• the lamps 107a to 107b which are lamp heaters, are alternately turned on and off to form a crystal growth film of better quality.
• FIG. 15 A STEM analysis was performed on the laminated structure obtained in the same manner as in Example 1. The results are shown in Figures 15-17. It can be seen from FIG. 15 that a buried layer 1004 is formed between the crystal substrate 1011 and the epitaxial layer 1001, and furthermore, amorphous layers 1002 and 1003 are formed. Further, from FIG. 16, it can be seen that the first amorphous layer 1002 on the crystal substrate 1011 contains Si of the crystal substrate and Zr which is a constituent metal of the epitaxial layer 1001. Furthermore, it can be seen that the second amorphous layer contains Si of the crystal substrate and Hf and Zr, which are the constituent metals of the epitaxial layer 1001. Further, from FIG. 17, it can be seen that the buried layer 1004 has a substantially inverted triangular cross-sectional shape and is an oxide containing Hf and Si.
• FIG. 9 shows an embodiment of an acoustic MEMS transducer constituting a MEMS microphone in which the laminated structure is preferably used in the present invention.
• the MEMS transducer can constitute a sound emitting device (for example, a speaker, etc.).
• the MEMS microphone configured with the acoustic MEMS transducer shown in FIG. 9 is a cantilever type MEMS microphone, and includes a Si substrate 21 having two cantilever beams 28A and 28B and a cavity 30. Each cantilever beam 28A, 28B is fixed to the substrate 21 at a respective end, and a gap 9 is provided between the cantilever beams 8A, 8B.
• the cantilever beams 8A, 8B are formed, for example, by a laminated structure including a plurality of piezoelectric layers (PZT films) 26a, 26b, and a plurality of electrode layers, that is, Pt films 24a, 24b, 24c and SRO films 25a, 25b. , 25c, and 25d alternately.
• PZT films piezoelectric layers
• a dielectric layer (single crystal film of crystalline oxide) 23 electrically insulates the cantilever beams 8A, 8B from the crystal substrate 21.
• a neutron absorbing material for example, HfO 2 or its mixed crystal
• SiO 2 or SiN is used for the dielectric layer (single crystal film of crystalline oxide) 23, and compared to the case where SiO 2 or SiN is used, Si It has excellent adhesion to the substrate and crystallinity, and also has excellent piezoelectric properties and durability.
• FIG. 10 shows an example of application to a fluid ejecting device that can be used in printing applications, particularly in the form of an inkjet print head, in which the laminated structure is suitably used in the present invention.
• a fluid ejecting device that can be used in printing applications, particularly in the form of an inkjet print head, in which the laminated structure is suitably used in the present invention.
• the wafer in FIG. 10 includes a chamber 41 for containing fluid. Chamber 41 is configured to receive fluid from a tank (not shown) via channel 40 .
• a neutron absorbing material for example, HfO 2 or its mixed crystal
• Si It has excellent adhesion to the substrate and crystallinity, and also has excellent piezoelectric properties and durability.
• the crystalline oxide single crystal film 33 has, for example, a quadrilateral shape in a top view (not shown), and such a shape may be, for example, a square, a rectangle, a rectangle with rounded corners, or a parallelogram. It may be any of the following.
• a Pt film 34a, an SRO film 35a, a piezoelectric film (PZT film) 36, an SRO film 35b, and a Pt film 34b are laminated in this order on the single crystal film 33 of crystalline oxide, and constitute a piezoelectric actuator.
• the piezoelectric actuator further includes an insulating film 37 extending over the electrodes 34a and 35a, the piezoelectric film 36, and the electrodes 34b and 35b.
• the insulating film 37 includes a dielectric material used for electrical insulation, and such dielectric material may be a known dielectric material, such as a SiO2 layer, a SiN layer, or an Al2O3 layer. .
• the thickness of the insulating layer containing the insulating film as a constituent material is not particularly limited, but is preferably between about 10 nm and about 10 ⁇ m.
• the conductive path 39 is provided on the insulating layer (insulating film) 37 and contacts the electrodes 34a and 35a and the electrodes 34b and 35b, respectively, allowing selective access during use.
• the material constituting the conductive path may be a known conductive material, and a suitable example of such a conductive material is aluminum (Al).
• 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 may be made of a dielectric material used for passivation of the piezoelectric actuator, and such dielectric material is not particularly limited, and may be a known dielectric material. Suitable examples of the dielectric material include SiN and SION (silicon oxynitrate). The thickness of the passivation layer is not particularly limited, but is preferably between about 0.1 ⁇ m and about 3 ⁇ m. Further, a conductive pad 38 is similarly provided along the piezoelectric actuator and is electrically connected to the conductive path 39. Note that the passivation layer 42 functions as a barrier layer that protects the piezoelectric body from humidity and the like.
• the piezoelectric body and laminated structure of the present invention are suitably used, for example, as electronic devices such as piezoelectric devices, and suitably used in electronic equipment, sensor systems, and the like.

Landscapes

• Engineering & Computer Science (AREA)
• Chemical & Material Sciences (AREA)
• Manufacturing & Machinery (AREA)
• Chemical Kinetics & Catalysis (AREA)
• Materials Engineering (AREA)
• Mechanical Engineering (AREA)
• Metallurgy (AREA)
• Organic Chemistry (AREA)
• Ceramic Engineering (AREA)
• Crystals, And After-Treatments Of Crystals (AREA)
• Piezo-Electric Or Mechanical Vibrators, Or Delay Or Filter Circuits (AREA)

Priority Applications (1)

Applications Claiming Priority (4)

Publications (1)

Family

ID=88023707

Family Applications (1)

Country Status (3)

Citations (4)

• 2023
  • 2023-03-13 TW TW112109206A patent/TW202401860A/zh unknown
  • 2023-03-13 WO PCT/JP2023/009575 patent/WO2023176757A1/ja not_active Ceased
  • 2023-03-13 JP JP2024508143A patent/JP7651230B2/ja active Active

Patent Citations (4)

Also Published As

Similar Documents

Legal Events