Laminated structure, electronic device, electronic equipment and system

Abstract

[Problem] To provide: a crystal having excellent crystallinity; a layered structure; and an element, an electronic device, an electronic apparatus, and a system that use the crystal and the layered structure. [Solution] This layered structure is produced by forming at least a compound film on a crystal substrate, and then layering a crystal film containing a crystal made of a crystalline metal compound product containing metal compound products including compound products of Hf, Zr, and Si as main components. The layering is performed by forming the crystal film using compound elements in the compound film.

Description

[Technical Field]

[0001] The present invention relates to a crystal, a layered structure, an element, an electronic device, an electronic apparatus, and a system. [Background technology]

[0002] Conventionally, SOI (Silicon On Insulator) technology has been known, which uses an SiO2 film to separate elements in order to prevent malfunctions and breakdowns of ICs caused by horizontal and vertical parasitic elements that occur in PN isolation. In recent years, methods have been considered in which multiple semiconductor elements with different breakdown voltages are formed on a single semiconductor substrate, and in particular, application of this technology to wide bandgap semiconductors (such as SiC and GaN) has also been considered (Patent Document 1).

[0003] Also, attempts have been made to form devices on flexible substrates such as plastic using SOI technology. For example, as disclosed in Patent Document 2, one method involves using a completed SOI substrate to partially open a window in the SOI layer, exposing a BOX (Buried Oxide) layer, and then performing HF etching, which allows the HF to penetrate laterally, etching the BOX and forming pillars. After forming the pillars, another method involves attaching the SOI layer to PET (polyethylene terephthalate) or the like, peeling it off from the substrate at the pillar portion, and forming the SOI layer on PET or the like, thereby transferring the SOI layer on which the device was fabricated onto the flexible substrate.

[0004] However, none of the SOI technologies are yet satisfactory in terms of the crystallinity of the semiconductor film formed on the insulating film, the crystallinity of the insulating film, or the insulating properties, and further improvements in crystallinity and semiconductor properties are desired. Also, there is a need for SOI technology that can bring good crystallinity not only to semiconductors but also to piezoelectric materials as a buffer layer. Furthermore, since the process of peeling and transferring the SOI layer is complicated and peeling is difficult, a new SOI technology that allows for easy peeling and transfer is also desired. [Prior art documents] [Patent documents]

[0005] [Patent Document 1] Patent Publication No. 2021-5718 [Patent Document 2] Japanese Patent Application Laid-Open No. 2014-179580 Summary of the Invention [Problem to be solved by the invention]

[0006] An object of the present invention is to provide a crystal having excellent crystallinity, a layered structure, and an element, an electronic device, an electronic equipment, and a system using the same. [Means for solving the problem]

[0007] As a result of intensive research into achieving the above-mentioned object, the inventors have made various discoveries, including the following: when forming at least a compound film on a crystal substrate and then laminating a crystal film containing crystals made of a crystalline metal compound containing as a main component a metal compound including a compound of Hf, Zr, and Si, by forming the crystal film using the compound elements in the compound film, a crystal and a laminated structure having excellent crystallinity can be easily obtained; when a conductive film, a semiconductor film, or a piezoelectric film is formed on the crystal, the crystal has excellent crystallinity and is very excellent in various properties of the electrode and the functional film; the crystal is particularly suitable as a buffer layer for forming a functional film; and the crystal is also useful for peeling and transferring. They have also found that such a crystal and a laminated structure can solve the above-mentioned conventional problems in one fell swoop. Furthermore, after obtaining the above findings, the present inventors conducted further studies and completed the present invention.

[0008] That is, the present invention relates to the following inventions. [1] A crystal consisting of a crystalline metal compound containing a metal compound as a main component, characterized in that the metal compound contains compounds of Hf, Zr, and Si. [2] The crystal according to [1], wherein the crystalline metal compound has a cubic or hexagonal crystal structure. [3] The crystal according to [2], wherein the crystalline metal compound is oriented in (111), (100), (010) or (0001). [4] The crystal according to any one of [1] to [3], wherein the crystalline metal compound contains a compound of Si in an amount of 5 atomic % or more relative to the crystalline metal compound. [5] The crystal according to any one of [1] to [4], wherein the crystalline metal compound contains a compound of Hf and a compound of Zr in an amount of 50 atomic % or more relative to the crystalline metal compound. [6] The crystal according to any one of [1] to [5] above, which is a ferroelectric. [7] The crystal according to any one of [1] to [6] above, which is in the form of a film. [8] The crystal according to [7] above, having a film thickness of 1 μm or more. [9] A laminated structure in which a crystal film is laminated on a crystal substrate directly or via another layer, characterized in that the crystal film is made of the crystal according to any one of [1] to [8] above.

[10] The laminated structure according to [9], wherein the crystal film constitutes a part or all of a buffer layer and is a substrate for crystal growth.

[11] An element including a crystal or a laminated structure, wherein the crystal is the crystal described in any one of [1] to [8] above, or the laminated structure is the laminated structure described in [9] or

[10] above.

[12] The element according to

[11] above, which is a piezoelectric element or a semiconductor element.

[13] An electronic device comprising a crystal or a laminated structure, wherein the crystal is the crystal described in any one of [1] to [8] above, or the laminated structure is the laminated structure described in [9] or

[10] above.

[14] The electronic device according to

[13] above, which is a piezoelectric device or a semiconductor device.

[15] An electronic device including an electronic device, characterized in that the electronic device is the electronic device described in

[13] or

[14] above.

[16] A system including an electronic device, characterized in that the electronic device is the electronic device described in

[15] above.

[17] A method for manufacturing a laminated structure, which comprises forming at least a compound film on a crystal substrate, and then laminating a crystal film containing crystals made of a crystalline metal compound containing a metal compound as its main component, characterized in that the lamination is carried out by forming the crystal film using compound elements in the compound film.

[18] The method according to

[17] , wherein the metal compound includes compounds of Hf, Zr, and Si.

[19] The laminated structure according to [9], wherein, between the crystal substrate and the crystal film, there is provided one or more embedded layers that are embedded in a portion of the crystal film and / or the crystal substrate and contain the constituent metals of the crystal film and / or the crystal substrate.

[20] The laminated structure according to

[19] , which has, between the crystal substrate and the crystal film, an amorphous thin film containing a constituent metal of the crystal film and / or one or more embedded layers embedded in a portion of the crystal substrate and containing a constituent metal of the crystal film.

[21] The laminated structure according to

[19] , which has, between the crystal substrate and the crystal film, an amorphous thin film containing a constituent metal of the crystal film and / or the crystal substrate, and one or more embedded layers embedded in a portion of the crystal substrate and containing the constituent metal.

[22] The laminate structure according to any one of

[19] to

[21] , wherein the constituent metal contains Hf.

[23] The laminate structure according to any one of

[19] to

[22] above, wherein the amorphous thin film has a thickness of 1 nm to 10 nm.

[24] The multilayer structure according to any one of

[19] to

[23] , wherein the embedded layer has a cross-sectional shape of a substantially inverted triangle.

[25] An electronic device, electronic equipment, or system including a laminated structure, characterized in that the laminated structure is the laminated structure according to any one of

[19] to

[24] .

[26] A crystal consisting of a crystalline metal compound containing a metal compound as a main component, characterized in that the metal compound contains Hf and / or Zr and Si.

[27] A crystal consisting of a crystalline metal compound containing a metal compound as a main component, characterized in that the metal compound contains Hf and Si. [Effects of the Invention]

[0009] The crystal and laminated structure of the present invention have excellent crystallinity, and elements, electronic devices, electronic equipment, and systems using the crystal and laminated structure have the effect of improving the properties of their respective functional films. [Brief explanation of the drawings]

[0010] [Figure 1] 1 is a diagram schematically illustrating an example of a preferred embodiment of the laminated structure of the present invention. [Figure 2] FIG. 1 is a diagram schematically showing an SOI island formation process in peel-and-transfer, which is an example of a suitable application of the laminated structure of the present invention. [Figure 3] FIG. 2 is a diagram schematically illustrating an HF etching step in peeling and transferring, which is an example of a suitable application of the laminated structure of the present invention. [Figure 4] FIG. 2 is a diagram schematically illustrating a step of attaching a laminated structure of the present invention to a flexible substrate in peeling and transfer, which is an example of a suitable application of the laminated structure of the present invention. [Figure 5] FIG. 2 is a diagram schematically illustrating a peeling step in peeling and transfer, which is an example of a suitable application of the laminated structure of the present invention. [Figure 6] 1A and 1B are diagrams schematically illustrating an example of an oxide film forming step in a preferred method for producing a laminated structure of the present invention. [Figure 7] 1A and 1B are diagrams schematically illustrating an example of an insulating film forming step in a preferred method for producing a laminated structure of the present invention. [Figure 8] 1 shows cross-sectional STEM images observed in Examples. [Figure 9] 1 shows the results of XRD analysis in the examples. [Figure 10] 1 is a diagram schematically illustrating a preferred example of an insulated gate bipolar transistor (IGBT) obtained in the present invention. [Figure 11] 11A to 11C are diagrams schematically illustrating an example of a suitable manufacturing process for the insulated gate bipolar transistor (IGBT) of FIG. [Figure 12] FIG. 1 is a diagram schematically illustrating a preferred example of a power supply system. [Figure 13] FIG. 1 is a diagram schematically illustrating a preferred example of a system device. [Figure 14] FIG. 1 is a diagram schematically illustrating a preferred example of a power supply circuit diagram of a power supply device. [Figure 15] FIG. 2 is a diagram schematically illustrating a film forming apparatus preferably used in the examples. [Figure 16] 1 shows a cross-sectional STEM image measured in an example. [Figure 17] 1 shows STEM images measured in the example. [Figure 18] 1 shows a STEM image of the buried layer measured in the example. [Figure 19] 1 shows the results of XRD measurements taken in Examples. DETAILED DESCRIPTION OF THE INVENTION

[0011] The crystal of the present invention is a crystal made of a crystalline metal compound containing a metal compound as a main component, characterized in that the metal compound contains a compound of Hf, Zr, and Si. The crystal may be a single crystal or a polycrystal. Furthermore, in the present invention, the crystal is a crystal made of a crystalline metal compound containing a metal compound as a main component, and the metal compound is preferably a crystal containing Hf and / or Zr and Si, and more preferably the metal compound contains Hf and Si.

[0012] The crystalline metal compound is not particularly limited as long as it contains the metal compound as the main component, and the metal compound preferably contains compounds of Hf, Zr, and Si. The "main component" may be, for example, a compound of Hf, Zr, and Si in which the atomic ratio of the metal compound in the crystal is 0.5 or more. In the present invention, the atomic ratio of Hf, Zr, and Si to all metal elements in the metal compound is preferably 0.7 or more, and more preferably 0.8 or more.

[0013] In the present invention, the crystalline metal compound preferably has a cubic or hexagonal crystal structure, and more preferably has a (111), (100), (010), or (0001) orientation. Furthermore, in the present invention, the crystalline metal compound preferably contains 5 atomic % or more of a Si compound relative to the crystalline metal compound, and also preferably contains 50 atomic % or more of a Hf compound and a Zr compound relative to the crystalline metal compound. This preferred range is preferable because it can be used not only as an excellent buffer layer but also exhibits good ferroelectric properties and further improves electrical properties (particularly the interface between the conductive layer and the insulating layer). The crystalline metal compound may also be a known compound, such as an oxide, nitride, oxynitride, sulfide, oxysulfide, boride, oxyboride, carbide, oxycarbide, borocarbide, boronitride, borosulfide, carbonitride, carbosulfide, or carboboride. In the present invention, an oxide or nitride can provide, for example, superior stress relaxation and warpage reduction during heteroepitaxial growth as a buffer layer. In the present invention, the crystalline metal compound is preferably a crystalline metal oxide, the compound film is preferably an oxide film, and the compound element is preferably oxygen. In the present invention, the crystalline metal compound is preferably a crystalline metal oxide, the compound film is preferably an oxide film, and the compound element is preferably oxygen. Furthermore, in the present invention, the crystalline metal compound is preferably a crystalline nitride, the compound film is preferably a nitride film, and the compound element is preferably nitrogen.

[0014] In the present invention, the crystals are preferably in the form of a film (hereinafter also referred to as "crystal film"). If the crystals are in the form of a film, it is preferable that the film thickness is 1 μm or more from the viewpoint of pressure resistance, etc. Such preferred crystals can be easily obtained by forming at least an oxide film on a crystal substrate, and then laminating a crystal film containing crystals made of a crystalline metal oxide containing a metal oxide as a main component, by forming the crystal film using oxygen atoms in the oxide film. The means for forming the crystal film is not particularly limited and may be a known means (e.g., MBE method, ion plating method, etc.), and the crystal growth conditions, etc. can also be set appropriately. The laminate structure obtained by the above method and the method for producing the same are also encompassed by the present invention.

[0015] FIG. 1 shows a preferred example of the laminated structure. In the laminated structure of FIG. 1, the film-like crystal is laminated on a crystal substrate 1 using an oxide film as a first epitaxial layer 3, and a conductive film, a semiconductor film, or a piezoelectric film is further laminated on the first epitaxial layer 3 as a second epitaxial layer 4. In this specification, the terms "film" and "layer" may be interchangeable depending on the case or situation. Furthermore, although oxides are given as preferred examples of the laminated structure, the present invention is not limited to these preferred examples, and the present invention can also be suitably applied to various compounds such as nitrides.

[0016] The laminated structure can be easily manufactured by forming an oxide film 2 of the crystal substrate 1 on the crystal substrate 1, for example, as shown in Fig. 6, and then using oxygen in the oxide film 2 to form a crystal film (first epitaxial layer) 3 made of the crystalline metal oxide on the crystal substrate 1, as shown in Fig. 7. In the present invention, the laminated structure may have the oxide film 2 on the crystal substrate 1, or the oxide film 2 may disappear when all of the oxygen in the oxide film 2 is taken in during the formation of the crystal film 3. Preferred embodiments of the present invention will be described in more detail below, but the present invention is not limited to these specific examples.

[0017] The crystal substrate (hereinafter simply referred to as "substrate") is not particularly limited in terms of substrate material, etc., as long as it does not impede the objectives of the present invention, and may be a known crystal substrate. It may be an organic compound or an inorganic compound. In the present invention, the crystal substrate preferably contains an inorganic compound. In the present invention, the substrate preferably has crystals on part or all of its surface, more preferably a crystal substrate having crystals on all or part of the main surface on the crystal growth side, and most preferably a crystal substrate having crystals on the entire main surface on the crystal growth side. The crystal is not particularly limited as long as it does not impede the objectives of the present invention, and the crystal structure is also not particularly limited. However, it is preferably a cubic, tetragonal, trigonal, hexagonal, orthorhombic, or monoclinic crystal, more preferably a cubic or hexagonal crystal, and most preferably a (111), (100), or (0001) orientation. The crystal substrate may also have an off-angle, and the off-angle may be, for example, 0.2° to 12.0°. Here, the "off-angle" refers to the angle between the substrate surface and the crystal growth plane. The substrate shape is not particularly limited as long as it is plate-like and serves as a support for the insulating film. It may be an insulating substrate or a semiconductor substrate. However, in the present invention, the substrate is preferably a Si substrate, more preferably a crystalline Si substrate, and most preferably a crystalline Si substrate with a (111), (100), or (0001) orientation. Examples of the substrate material include Si substrates and 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 substantially circular (e.g., circular, elliptical, etc.) or polygonal (e.g., triangular, square, rectangular, pentagonal, hexagonal, heptagonal, octagonal, nonagonal, etc.), and various shapes can be suitably used.

[0018] In the present invention, the crystal substrate preferably has a flat surface. However, it is also preferable for the crystal substrate to have an uneven surface on part or all of its surface, as this can improve the quality of crystal growth of the crystal film. The crystal substrate having an uneven surface may have an uneven surface consisting of concave or convex portions formed on part or all of its surface. The uneven surface is not particularly limited as long as it consists of convex or concave portions. It may be an uneven surface consisting of convex portions, an uneven surface consisting of concave portions, or an uneven surface consisting of convex and concave portions. The uneven surface may also be formed of regular convex or concave portions, or irregular convex or concave portions. In the present invention, the uneven surface is preferably formed periodically, and more preferably in a periodic and regularly patterned form. The shape of the uneven surface is not particularly limited, and examples include stripes, dots, meshes, and random patterns. In the present invention, a dot or stripe pattern is preferred, and a dot pattern is more preferred. Furthermore, when the concave-convex portions are patterned periodically and regularly, the pattern shape of the concave-convex portions is preferably a polygonal shape such as a triangle, a quadrangle (e.g., a square, a rectangle, or a trapezoid), a pentagon, or a hexagon, or a circle, an ellipse, or the like. When the concave-convex portions are formed in a dotted pattern, the lattice shape of the dots is preferably a lattice shape such as a square lattice, an oblique lattice, a triangular lattice, or a hexagonal lattice, and more preferably a triangular lattice. The cross-sectional shape of the concave or convex portions of the concave-convex portions is not particularly limited, but examples thereof include a U-shape, an inverted U-shape, a wave shape, or a polygonal shape such as a triangle, a quadrangle (e.g., a square, a rectangle, or a trapezoid), a pentagon, or a hexagon. The thickness of the crystal substrate is not particularly limited, but is preferably 50 to 2000 μm, and more preferably 100 to 1000 μm.

[0019] The oxide film is not particularly limited as long as it is an oxide film capable of incorporating oxygen atoms into the crystal film, and typically contains an oxide material. The oxide material is not particularly limited as long as it does not impede the objectives of the present invention, and may be a known oxide material. Examples of the oxide material include metal or semimetal oxides. In the present invention, the oxide film preferably contains the oxide material of the crystal substrate. Examples of such oxide films include a thermally oxidized film or a natural oxide film of the crystal substrate. In addition, in the present invention, the oxide film may be a sacrificial layer that is partially or completely lost or destroyed when oxygen atoms are absorbed. In the present invention, the oxide film is preferably an oxygen supply sacrificial layer that absorbs oxygen atoms and loses the oxide film itself during the crystal growth of the epitaxial layer. In addition, the oxide film may be patterned, for example, in a striped, dotted, mesh, or random pattern. The thickness of the oxide film is not particularly limited, but is preferably greater than 1 nm and less than 100 nm.

[0020] The crystalline film (first epitaxial layer) preferably includes an epitaxial film incorporating oxygen atoms from the oxide film. Note that "an epitaxial film incorporating oxygen atoms from the oxide film" means that oxygen atoms from the oxide film are taken by the epitaxial film during the crystal growth of the epitaxial film. In addition, in the present invention, the crystalline film preferably includes a neutron absorbing material. The neutron absorbing material may be a known neutron absorbing material. In the present invention, by using such a neutron absorbing material to absorb oxygen from the oxide film, it is possible to improve adhesion, crystallinity, and other functional film properties. Note that hafnium (Hf) is a suitable example of the neutron absorbing material.

[0021] In the present invention, it is preferable that a second epitaxial layer made of a conductive film, a semiconductor film, or a piezoelectric film is stacked on the crystal film, either directly or via another layer. By stacking in this manner, the first epitaxial layer can be regularly transformed at the interface between the first epitaxial layer and the second epitaxial layer so that the lattice constant becomes substantially the same as that of the second epitaxial layer. A preferred example of the regular transformation is a transformation in which the shape changes to a peak-valley structure. In the present invention, it is preferable that the angles formed by adjacent peaks and valleys of the peak-valley structure are different from each other, and more preferably, the angles are within a range of 30° to 45°. Here, the first epitaxial layer usually has a first crystal plane and a second crystal plane, but since the transformation can cause a difference in lattice constant between the first crystal plane and the second crystal plane, it is preferable that the difference in lattice constant between the first crystal plane and the second crystal plane is within a range of 0.1% to 20%. In the present invention, since the first crystal plane can be made substantially the same as the lattice constant of the second epitaxial layer, it is easy to achieve a difference in lattice constant between the first epitaxial layer and the second epitaxial layer within a range of 0.1% to 20%.

[0022] In the present invention, when a conductive film is laminated on the crystalline film, and the conductive film is made of a single crystal film of a conductive metal, a large-area defect-free film can be easily obtained, and not only the function as an electrode but also the characteristics of the element can be improved. The conductive metal is not particularly limited as long as it does not impede the object of the present invention, and examples thereof include gold, silver, platinum, palladium, silver-palladium, copper, nickel, and alloys thereof, but in the present invention, it is preferable to include platinum. Note that in the present invention, according to the above-mentioned manufacturing method, it is preferable to obtain a film having a thickness of 100 nm. 2 A defect-free single crystal film can be obtained as an electrode with an area of ​​1000 nm or more. 2A defect-free single crystal film can be easily obtained with an area of ​​100 nm or more. Furthermore, a single crystal film having a thickness of 100 nm or more can be easily obtained as an electrode. When a conductive film made of a single crystal film of a conductive metal is laminated on the crystalline film, the laminated structure can be suitably used as an electrode substrate in which a crystalline conductive film is laminated on the insulating film.

[0023] The semiconductor film is not particularly limited as long as it contains a semiconductor, and may be a known semiconductor film, but in the present invention, it preferably contains a cubic semiconductor, such as c-BN, c-AlN, c-GaN, c-InN, c-SiC, GaAs, AlAs, InAs, GaP, AlP, InP, or a mixed crystal semiconductor thereof.

[0024] The piezoelectric film is not particularly limited as long as it is made of a piezoelectric material, and may be a film made of a known piezoelectric material, but in the present invention, a piezoelectric material having a trigonal or hexagonal crystal structure is preferred. Examples of the piezoelectric material include lead zirconate titanate (PZT), other ceramic materials having a so-called perovskite structure represented by the ABO3 type, such as barium titanate, lead titanate, potassium niobate, lithium niobate, lithium tantalate, sodium tungstate, zinc oxide, barium strontium titanate (BST), strontium bismuth tantalate (SBT), lead metaniobate, lead zinc niobate, lead scandium niobate, polyvinylidene fluoride, and quartz.

[0025] The thickness of each of the conductive film, the semiconductor film, and the piezoelectric film is not particularly limited, but is preferably 10 nm to 1000 μm, and more preferably 10 nm to 100 μm.

[0026] The laminated structure can be easily obtained by a method for manufacturing a laminated structure in which an insulating film is laminated on a crystal substrate via at least an oxide film, by forming a crystal film using oxygen atoms in the oxide film at 350° C. to 700° C. If the temperature is in the range of 350° C. to 700° C., the oxygen atoms in the oxide film can be easily incorporated into the crystal film to cause crystal growth.

[0027] In the present invention, the above stacking is preferably performed by using oxygen atoms in the oxide film, followed by deposition of the crystal film using oxygen gas. By forming the film in this manner, a stacked structure in which the crystal film is stacked on the crystal substrate can be easily obtained, with an amorphous thin film containing a constituent metal of the crystal film and / or the crystal substrate and / or one or more buried layers embedded in a portion of the crystal substrate and containing the constituent metal. In the present invention, it is preferable for the stacked structure to have both the amorphous layer and the buried layer, since this can further improve the functionality of the crystal film. It is also preferable for the amorphous layer and the buried layer to each contain a constituent metal of the crystal film, since this improves the crystallinity of the crystal film. In the present invention, it is also preferable for the constituent metal to contain Hf, since this further promotes stress relaxation and enables multi-stage stress relaxation. In addition, in the present invention, the thickness of the amorphous thin film is preferably 1 nm to 10 nm, since this can further improve the crystallinity of the crystalline film, and an amorphous thin film of such a preferred thickness can be easily obtained by the preferred manufacturing method of the present invention. Also, in the present invention, it is preferable that the shape of the buried layer has a substantially inverted triangular cross section, since this can further improve the functionality of the crystalline film. Note that these preferred stacked structures can be easily obtained by appropriately adjusting the thickness of the oxide film, the timing of introducing the oxygen gas, etc.

[0028] The lamination means used in the lamination is usually a means for depositing the insulating film, and the film deposition means may be a known film deposition means. In the present invention, the film deposition means is preferably vapor deposition or sputtering.

[0029] The laminated structure obtained as described above can be used in a device as is or after further processing, etc., according to a conventional method. When the laminated structure is used in a device, it may be used as is, or it may be used after forming other layers (e.g., an insulating layer, a semi-insulating layer, a conductor layer, a semiconductor layer, a buffer layer, or other intermediate layers). In the present invention, the laminated structure is preferably used as an SOI substrate in which a functional film (e.g., a semiconductor film, a piezoelectric film, etc.) is laminated on the crystalline film.

[0030] The element is used in a conventional manner, for example, in an electronic device (preferably a piezoelectric device). More specifically, for example, the element can be connected as a piezoelectric element to a power source or an electric / electronic circuit, and mounted on a circuit board or packaged to form various electronic devices. In the present invention, the electronic device is preferably a piezoelectric device, and more preferably a piezoelectric device in an electronic device such as a gyroscope or a motion sensor. Furthermore, for example, if an amplifier and a rectifier circuit are connected and packaged, the electronic device can be used in various sensors such as a magnetic sensor.

[0031] The electronic device is suitably used in electronic devices in the usual manner, and can be applied to various electronic devices in addition to the above-mentioned electronic devices, and more specific examples of suitable electronic devices include liquid ejection heads, liquid ejection apparatuses, vibration wave motors, optical devices, vibration devices, imaging devices, piezoelectric acoustic components, and audio playback devices, audio recording devices, mobile phones, and various information terminals that have such piezoelectric acoustic components.

[0032] In the present invention, the element is preferably a semiconductor element, and the electronic device is preferably a semiconductor device. The semiconductor element or semiconductor device (hereinafter collectively referred to as "semiconductor device") is not particularly limited as long as it does not impede the object of the present invention, and may be a known semiconductor element or semiconductor device. It may be a vertical device or a lateral device, but in the present invention, a lateral device is preferred. Examples of the semiconductor device include diodes and transistors (e.g., MOSFETs or JFETs), but insulated gate semiconductor devices (e.g., MOSFETs or IGBTs) or semiconductor devices having a Schottky gate (e.g., MESFETs) are preferred, MOSFETs and / or IGBTs are more preferred, and lateral MOSFETs and / or lateral IGBTs are most preferred.

[0033] 10 shows a lateral IGBT, a lateral NMOS, and a lateral PMOS suitable for the present invention. The lateral IGBT, the lateral NMOS, and the lateral PMOS of FIG. 1 have an insulating film 26a formed as the crystalline film on a crystalline substrate 29, and each element is provided on the insulating film 26a. The lateral IGBT of FIG. 10 has a gate electrode 21, an emitter electrode 22, a collector electrode 23, an insulating film 26 as the crystalline film, a p-type semiconductor 27, an n-type semiconductor 28, and an n-type semiconductor 29. - 10 includes a gate electrode 21, a drain electrode 24, a source electrode 25, an insulating film 26, a p-type semiconductor 27, an n-type semiconductor 28, and an n-type semiconductor 29. - 10 includes a gate electrode 21, a drain electrode 24, a source electrode 25, an insulating film 26, a p-type semiconductor 27, and an n-type semiconductor 28a. - The semiconductor 28a is a semiconductor having a thickness of 100 .mu.m.

[0034] 11 shows a preferred manufacturing process for the insulated gate bipolar transistor (IGBT) shown in FIG. 10. In the manufacturing process shown in FIG. 11, an insulating film 26a is formed as the crystalline film on a crystalline substrate 29, and an n-type insulating film 26a is formed on the insulating film 26a. -In FIG. 11(a), a trench is formed in the laminated structure by a known method, and further, an n-type semiconductor (e.g., a Si semiconductor) 28a is formed in the laminated structure. - The surface side of the type semiconductor (e.g., Si semiconductor) 28a is oxidized. In FIG. 11(b), the stacked structure of FIG. 11(a) is treated with polysilicon 31 using known means to fill the trenches with polysilicon 31, and a polysilicon layer is further formed on the oxidized surface. In FIG. 11(c), the stacked structure of FIG. 11(b) is polished using known means to obtain the stacked structure of FIG. 11(c). The obtained stacked structure is then subjected to various device fabrication processes using known means.

[0035] The lateral IGBT, lateral NMOS, and lateral PMOS obtained in this way utilize element isolation using a trench isolation structure, resulting in a small isolation area and enabling inverters to be constructed directly from a rectified and smoothed commercial power supply. Furthermore, a high-voltage output section and control circuit section can be constructed on the same chip, enabling the realization of an excellent power IC. In particular, because each device within the IC is completely isolated by a dielectric, it is possible to eliminate the effects of parasitic elements, resulting in a highly reliable system.

[0036] In addition to the above features, the semiconductor device can be suitably used as a semiconductor device such as a power module, inverter, or converter using known means, and further suitably used in a semiconductor system using a power supply device as a semiconductor device. The power supply device can be fabricated using known means, such as by connecting the semiconductor device to a wiring pattern. FIG. 12 shows an example of a power supply system. FIG. 12 shows a power supply system configured using multiple power supply devices and a control circuit. The power supply system can be combined with an electronic circuit, as shown in FIG. 13, to form a system device. FIG. 14 shows an example of a power supply circuit diagram for a power supply device. FIG. 14 shows the power supply circuit of a power supply device consisting of a power circuit and a control circuit. The inverter (comprising MOSFETs A to D) switches DC voltage at high frequency to convert it to AC, then insulates and transforms it with a transformer, rectifies it with rectifier MOSFETs (A to B'), smooths it with DCLs (smoothing coils L1 and L2) and a capacitor, and outputs a DC voltage. At this time, a voltage comparator compares the output voltage with a reference voltage, and a PWM control circuit controls the inverter and rectifier MOSFETs to achieve the desired output voltage. [Example]

[0037] Example 1 The crystal growth surface of a Si substrate (100) was treated by RIE and heated in the presence of oxygen to form a thermal oxide film. Then, without oxygen, a metal vapor deposition method was used to thermally react with oxygen in the oxide film on the Si substrate, forming a crystalline metal oxide single crystal on the Si substrate. Next, oxygen was introduced, the temperature was lowered, and the pressure was increased, and a crystalline metal oxide single crystal film was formed by vapor deposition. The vapor deposition conditions for this film formation were as follows: Vapor deposition source: Hf, Zr, Si Voltage: 3.5~4.75V Pressure: 3×10 -2 ~6×10 -2 Pa Substrate temperature: 450~700℃

[0038] The resulting laminated structure contained a crystalline film with good adhesion and crystallinity. The resulting crystalline film had a thickness of 20 μm and exhibited ferroelectricity. Figure 8 shows a cross-sectional STEM image of the resulting laminated structure. Furthermore, when the resulting crystalline film was examined using an X-ray diffractometer, it was found to be (Hf, Zr, Si)O2. XRD The analysis results are shown in Figure 9.

[0039] Example 2 A laminated structure was obtained in the same manner as in Example 1, except that a Si substrate was used instead of a (111) Si substrate. The obtained laminated structure was a laminated structure including a crystalline film with good adhesion and crystallinity, as in Example 1, and exhibited ferroelectricity. Furthermore, when the obtained crystalline film was examined using an X-ray diffraction apparatus, it was found to be (Hf, Zr, Si)O2.

[0040] Example 3 A laminated structure was obtained in the same manner as in Example 1, except that Zr was not used. The obtained laminated structure was a laminated structure including a crystalline film having good adhesion and crystallinity, and exhibited ferroelectricity, as in Example 1. Furthermore, when the obtained crystalline film was examined using an X-ray diffraction device, it was found to be (Hf, Si)O2, as shown in Figure 19.

[0041] The evaporation film-forming apparatus used in Example 1 is shown in Fig. 15. The film-forming apparatus in Fig. 15 includes at least metal sources 101a-101b in a crucible, earths 102a-102h, ICP electrodes 103a-103b, cut filters 104a-104b, DC power supplies 105a-105b, RF power supplies 106a-106b, lamps 107a-107b, an Ar source 108, a reactive gas source 109, a power supply 110, a substrate holder 111, a substrate 112, a cut filter 113, an ICP ring 114, a vacuum chamber 115, and a rotation shaft 116. The ICP electrodes 103a-103b in Fig. 15 have a generally concave curved or parabolic shape curved toward the center of the substrate 112.

[0042] As shown in FIG. 15, the substrate 112 is secured on the substrate holder 111. Next, the rotary shaft 116 is rotated using the power supply 110 and a rotation mechanism (not shown), thereby rotating the substrate 112. The substrate 112 is heated by lamps 107a and 107b, and a vacuum chamber 115 is evacuated using a vacuum pump (not shown) to create a vacuum or reduced pressure. Thereafter, Ar gas is introduced from the Ar source 108 into the vacuum chamber 115, and argon plasma is formed on the substrate 112 using the DC power supplies 105a and 105b, the RF power supplies 106a and 106b, the ICP electrodes 103a and 103b, the cut filters 104a and 104b, and the earths 102a and 102h, thereby cleaning the surface of the substrate 112.

[0043] Ar gas is introduced into the vacuum chamber 115, and a reactive gas is introduced using a reactive gas source 109. At this time, lamps 107a to 107b, which are lamp heaters, are turned on and off alternately, thereby enabling the formation of a better quality crystal growth film.

[0044] STEM analysis was performed on a stacked structure obtained in the same manner as in Example 1. A buried layer was formed between the crystalline substrate and the crystalline film, and two amorphous layers were also formed. The first amorphous layer on the crystalline substrate contained Si and Zr, a constituent metal of the crystalline film. The second amorphous layer contained Si from the crystalline substrate and Hf and Zr, constituent metals of the crystalline film. As a reference example, FIGS. 16 to 18 show the results of STEM analysis of a stacked structure containing a HfZrO mixed crystal fabricated in the same manner as in Example 1. FIG. 16 reveals that a buried layer 1004 is formed between the crystalline substrate 1011 and the epitaxial layer 1001, and that amorphous layers 1002 and 1003 are also formed. FIG. 17 reveals that the first amorphous layer 1002 on the crystalline substrate 1011 contains Si from the crystalline substrate and Zr, a constituent metal of the epitaxial layer 1001. It is also seen that the second amorphous layer contains Si of the crystalline substrate and Hf and Zr, which are constituent metals of the epitaxial layer 1001. It is also seen from Fig. 18 that the buried layer 1004 has a cross section shaped like an inverted triangle and is an oxide containing Hf and Si.

[0045] (Application example) An example of peeling and transferring, which is one of the preferred applications of the obtained laminated structure, will be described in more detail below with reference to the drawings, but the present invention is not limited to these application examples. In the following application examples, the crystal film is used as an insulating film. In the present invention, unless otherwise specified, an SOI substrate, an SOI semiconductor device, or the like can be manufactured from the laminated structure using known means.

[0046] Fig. 1 is a diagram showing a preferred example of the laminated structure of the present invention. The laminated structure of Fig. 1 has an insulating film 3 formed on a crystal substrate 1, and further has a semiconductor layer formed as a second epitaxial layer 4 on the insulating film 3.

[0047] FIG. 2 shows a stacked structure obtained in the SOI island formation step in the peel-and-transfer process. In the SOI island formation step, the stacked structure of FIG. 1 is used as an SOI substrate, and photolithography is performed to partially remove the semiconductor layer (second epitaxial layer) 4. In this manner, the stacked structure of FIG. 2 is obtained. In the stacked structure of FIG. 2, the second epitaxial layer is separated into two islands, and a first island 4a and a second island 4b of the second epitaxial layer are formed on an insulating film 3.

[0048] FIG. 3 shows a laminated structure obtained in the HF etching step in the peel-and-transfer process. In the HF etching step, the laminated structure of FIG. 2 is used, and the BOX layer is etched with HF to leave pillar-shaped residue. In the laminated structure of FIG. 3, the insulating film is pillar-shaped, and first pillar 3a and second pillar 3b of the insulating film (first epitaxial layer) are formed on crystal substrate 1. In the present invention, the adhesion between the crystal substrate and the insulating film is high, and stress relaxation such as transformation is usually observed at the interface between the insulating film and the second epitaxial layer, so peeling is easy. For example, the HF etching step is not essential and can be omitted.

[0049] Fig. 4 shows the laminated structure obtained in the step of attaching to a flexible substrate in the peel-and-transfer process. In the attaching step, the laminated structure shown in Fig. 3 is used to attach the SOI layer surface to a flexible substrate 5 made of, for example, PE (polyethylene) in close contact with the SOI layer surface.

[0050] Figure 5 shows the stacked structure obtained in the peeling process of the peeling and transfer process. In this peeling process, the SOI layer is peeled and transferred to a flexible substrate. This process improves the transfer success rate, increasing the yield in device manufacturing and enabling higher quality and lower costs. [Industrial Applicability]

[0051] The crystal and layered structure of the present invention are useful for elements, electronic devices, electronic equipment and systems, and are particularly suitable for use as SOI substrates. [Explanation of symbols]

[0052] 1. Crystal substrate 2. Oxide film 3. Insulating film (first epitaxial layer) 3a First pillar of first epitaxial layer 3b Second pillar of first epitaxial layer 4 Second epitaxial layer 4a First island of second epitaxial layer 4b Second island in second epitaxial layer 5 Flexible PCB 13 Insulating film 14 Conductive film 21 gate electrode 22 Emitter electrode 23 Collector electrode 24 Drain electrode 25 Source electrode 26 insulating film 26a Insulating film (epitaxial layer) 27 p-type semiconductors 28 n-type semiconductor 28a n - type semiconductor 29 Crystal Substrate 30 Trench Isolation 31 Polysilicon 101a~101b Metal source 102a~102j Earth 103a~103b ICP electrode 104a~104b Cut Filter 105a~105b DC power supply 106a~106b RF power supply 107a~107b Lamps 108 Ar source 109 Reactive Gas Source 110 Power supply 111 PCB holder 112 PCB 113 Cut Filter 114 ICP Ring 115 Vacuum chamber 116 Rotation axis 1001 Crystalline Film 1002 First amorphous layer 1003 Second amorphous layer 1004 buried layer 1011 board

Claims

1. A laminated structure in which a crystalline film made of a crystalline metal compound containing a compound of Hf, Zr, and Si as a main component is laminated on a crystalline substrate which is a Si substrate, a first amorphous layer formed between the crystal substrate and the crystal film and containing Zr and Si; a second amorphous layer formed between the first amorphous layer and the crystalline film and containing Hf, Zr, and Si; one or more buried layers embedded in a portion of the crystal substrate and containing Hf and Si; and The buried layer has a cross-sectional shape of a substantially inverted triangle.

2. an epitaxial layer formed on the crystal film and made of a conductive film, a semiconductor film, or a piezoelectric film; a regular peak-valley structure is provided at the interface between the crystal film and the epitaxial layer, 2. The laminated structure according to claim 1, wherein the angles formed by the adjacent vertices and bottoms of the peak-valley structure are different from each other within a range of 30° to 45°.

3. 2. The laminated structure according to claim 1, wherein a peak-valley structure is provided at the interface between the second amorphous layer and the crystalline film.

4. The laminated structure described in claim 1, wherein the crystalline metal compound contains a compound of Si at 5 atomic % or more relative to the crystalline metal compound, and a compound of Hf and a compound of Zr at 50 atomic % or more relative to the crystalline metal compound.

5. An electronic device, an electronic equipment, or a system including a laminate structure, wherein the laminate structure is the laminate structure according to any one of claims 1 to 4.

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