Laminated structure, electronic device, electronic equipment and system

Abstract

To provide a laminate structure having excellent crystallinity, semiconductor devices, and a manufacturing method that can obtain them industrially advantageously.SOLUTION: Provided is a laminate structure in which an insulating film containing a crystalline compound is stacked on a crystalline substrate and a crystalline conductive film or semiconductor film is further stacked on the insulating film. A semiconductor device is manufactured using the laminated structure in which the insulating film includes the crystalline compound to which compound elements in a compound film stacked on the crystalline substrate are incorporated.SELECTED DRAWING: Figure 1

Description

[Technical Field]

[0001] The present invention relates to a stacked structure, a semiconductor device, and a method for manufacturing the same. [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 these 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.In addition, when peeling and transferring the SOI layer, the process is complicated and peeling is difficult, so a new SOI technology that allows for easy peeling and transfer has been 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 laminated structure and a semiconductor device having excellent crystallinity, and a manufacturing method by which these can be obtained industrially advantageously. [Means for solving the problem]

[0007] As a result of extensive research into achieving the above-mentioned object, the present inventors have made various discoveries, including the following: a method for manufacturing a laminated structure in which an insulating film is laminated on a crystalline substrate via at least a compound film, and the lamination is carried out at 350°C to 700°C by forming an insulating film using compound elements in the compound film; a laminated structure containing an insulating film having excellent crystallinity can be easily obtained; and when a conductive film or a semiconductor film is formed on the insulating film, the resulting film has excellent crystallinity and excellent electrode properties and semiconductor properties, and is useful for peeling and transfer. These discoveries have led to the discovery that such a laminated structure and a method for manufacturing the same can solve all of the above-mentioned conventional problems at once. 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 laminated structure in which an insulating film containing a crystalline compound is laminated on a crystalline substrate, wherein the insulating film is characterized in that a compound element in a compound film laminated on the crystalline substrate is incorporated into the crystalline compound. [2] The layered structure according to [1], wherein the crystalline substrate is a crystalline Si substrate. [3] The laminated structure according to [1] or [2], wherein the compound film contains an oxide material of the crystal substrate. [4] The layered structure according to any one of [1] to [3], wherein the compound film has a thickness of more than 1 nm and less than 100 nm. [5] The laminated structure according to any one of [1] to [4], wherein the insulating film is an epitaxial film containing a crystalline compound. [6] A laminated structure in which an insulating film containing a crystalline compound is laminated on a crystalline substrate, and a crystalline conductive film or semiconductor film is further laminated on the insulating film, wherein the insulating film is characterized in that a compound element in the compound film laminated on the crystalline substrate is incorporated into the crystalline compound. [7] The stacked structure according to [6], comprising an SOI substrate having a semiconductor film stacked on the insulating film. [8] The laminated structure according to [6], comprising an electrode substrate having a crystalline conductive film laminated on the insulating film. [9] A method for manufacturing a laminated structure, which comprises forming at least a compound film on a crystal substrate and then laminating an insulating film thereon, characterized in that the lamination is carried out by forming the insulating film using a compound element in the compound film.

[10] The manufacturing method according to [9], wherein after using the compound element in the compound film, a compound element gas is introduced to form the insulating film in the presence of the compound element gas.

[11] The manufacturing method according to [9] or

[10] , wherein the lamination is performed by vapor deposition or sputtering.

[12] A semiconductor device including a stacked structure, characterized in that the stacked structure is the stacked structure according to any one of [1] to [8] above.

[13] The semiconductor device according to

[12] , comprising a lateral device.

[14] A method for manufacturing a semiconductor device using a stacked structure, wherein the stacked structure is the stacked structure according to any one of [1] to [8].

[15] A system including a semiconductor device, characterized in that the semiconductor device is the semiconductor device described in

[12] or

[13] above.

[16] The laminated structure according to [5], wherein, between the crystal substrate and the epitaxial film, there is provided one or more amorphous thin films containing the constituent metals of the epitaxial film and / or the crystal substrate and the compound element, and / or one or more embedded layers containing the constituent metals and the compound element embedded in a portion of the crystal substrate.

[17] The laminated structure according to

[16] , which has, between the crystal substrate and the epitaxial film, an amorphous thin film containing the constituent metal of the epitaxial film and the compound element, and / or one or more embedded layers embedded in a part of the crystal substrate and containing the constituent metal of the epitaxial film and the compound element.

[18] The laminated structure according to

[16] , having an amorphous thin film between the crystal substrate and the epitaxial film, the amorphous thin film containing the constituent metal of the epitaxial film and / or the crystal substrate and the compound element, and one or more embedded layers embedded in a portion of the crystal substrate and containing the constituent metal and the compound element.

[19] The laminate structure according to any one of

[16] to

[18] , wherein the constituent metal contains Hf.

[20] The laminate structure according to any one of

[16] to

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

[21] The multilayer structure according to any one of

[16] to

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

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

[16] to

[21] above. [Effects of the Invention]

[0009] The laminated structure and semiconductor device of the present invention have excellent crystallinity, and the manufacturing method of the present invention has the effect of making it possible to obtain the laminated structure and semiconductor device in an industrially advantageous manner. [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 STEM images observed in the examples. [Figure 10] 1 shows STEM images observed in the examples. [Figure 11] 1 is a diagram schematically illustrating a preferred example of an insulated gate bipolar transistor (IGBT) obtained in the present invention. [Figure 12] 12A to 12C are diagrams schematically illustrating an example of a suitable manufacturing process for the insulated gate bipolar transistor (IGBT) of FIG. 11. [Figure 13] FIG. 1 is a diagram schematically illustrating a preferred example of a power supply system. [Figure 14] FIG. 1 is a diagram schematically illustrating a preferred example of a system device. [Figure 15] FIG. 1 is a diagram schematically illustrating a preferred example of a power supply circuit diagram of a power supply device. [Figure 16] FIG. 1 is a diagram showing the results of XPS measurements in Examples. [Figure 17] FIG. 1 is a diagram showing the results of XPS measurements in Examples. [Figure 18] FIG. 2 is a diagram schematically illustrating a film forming apparatus preferably used in the examples. [Figure 19] 1 shows a cross-sectional STEM image measured in an example. [Figure 20] 1 shows STEM images measured in the example. [Figure 21] 1 shows a STEM image of the buried layer measured in the example. DETAILED DESCRIPTION OF THE INVENTION

[0011] The laminated structure of the present invention is a laminated structure in which an insulating film containing a crystalline compound is laminated on a crystalline substrate, and the insulating film is characterized in that a compound element in the compound film laminated on the crystalline substrate is incorporated into the crystalline compound. The crystalline compound is not particularly limited and may be a known crystalline compound, but in the present invention, the crystalline compound is preferably a metal compound, and the metal of the metal compound may also be a known metal. Examples of the metal include D-block metals in the periodic table. The metal compound may be a known compound. Examples of the crystalline compound include oxides, nitrides, oxynitrides, sulfides, oxysulfides, borides, oxyborides, carbides, oxycarbides, borocarbides, boronitrides, borosulfides, carbonitrides, carbosulfides, and carboborides. In the present invention, oxides or nitrides are preferred because they can, for example, provide better stress relaxation and warpage reduction as a buffer layer during heteroepitaxial growth, and can also provide better electrical properties (particularly the interface between the conductor layer and the insulating layer). The crystalline compound is preferably a crystalline oxide, the compound film is preferably an oxide film, and the compound element is preferably oxygen. In the present invention, the crystalline compound is preferably a crystalline nitride, the compound film is preferably a nitride film, and the compound element is preferably nitrogen. FIG. 1 shows a preferred example of the laminated structure. In the laminated structure of FIG. 1, a first epitaxial layer 3 is laminated on a crystal substrate 1 using an oxide film as the insulating film, and a second epitaxial layer 4 is laminated on the first epitaxial layer 3 as a conductive film or semiconductor film. 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.

[0012] The laminated structure of the present invention 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 an insulating film (first epitaxial layer) 3 made of a crystalline 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 the oxygen in the oxide film 2 is taken in during the formation of the insulating film 3. Each of these will be described in more detail below, but the present invention is not limited to these specific examples.

[0013] 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 a portion or all of its surface, more preferably a crystal substrate having crystals on all or a portion of its 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, crystals of a cubic, tetragonal, trigonal, hexagonal, orthorhombic, or monoclinic system are preferred, and crystals oriented in a (100) or (200) plane are more preferred. The crystal substrate may also 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 surface. The shape of the substrate is not particularly limited as long as it is plate-shaped 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 oriented in (100). Examples of the substrate material include Si substrates, as well as 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. Furthermore, in the present invention, a large-area substrate can be used, and the area of ​​the insulating film can be increased by using such a large-area substrate.

[0014] 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 improves the quality of the crystal growth of the insulating 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 thereof 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.

[0015] The oxide film is not particularly limited as long as it is an oxide film capable of incorporating oxygen atoms into the insulating 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-supplying sacrificial layer that absorbs oxygen atoms and loses the oxide film itself during the crystal growth of the epitaxial layer. The oxide film may also 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.

[0016] The insulating film (first epitaxial layer) is not particularly limited as long as it contains an insulator and further contains an epitaxial film incorporating oxygen atoms from the oxide film. The phrase "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. The epitaxial film is not particularly limited as long as it contains an insulator and is an epitaxial film grown by incorporating oxygen atoms from the oxide film. However, in the present invention, it preferably contains a crystalline oxide, more preferably a metal oxide. Suitable examples of the metal oxide include oxides of one or more metals belonging to the d-block of the periodic table, or silicon oxide. Furthermore, in the present invention, it is preferable that the insulating film contains 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 capture oxygen from the oxide film, it is possible to improve adhesion, crystallinity, and other functional film properties. A suitable example of the neutron absorbing material is hafnium (Hf), etc. The insulating film may be made up of one or more types of epitaxial films.

[0017] In the present invention, a second epitaxial layer made of a conductive or semiconductor film is preferably stacked on the insulating film, either directly or via another layer. This stacking allows the first epitaxial layer to be regularly transformed at the interface between the first and second epitaxial layers so that the lattice constant of the first epitaxial layer becomes substantially identical to that of the second epitaxial layer. A preferred example of this regular transformation is a transformation in which the shape is transformed into a peak-valley structure. In the present invention, the angles formed by adjacent peaks and valleys of the peak-valley structure are preferably different, more preferably within a range of 30° to 45°. The first epitaxial layer typically has a first crystal plane and a second crystal plane. Since the transformation can cause a difference in lattice constant between the first crystal plane and the second crystal plane, the difference in lattice constant between the first crystal plane and the second crystal plane is preferably within a range of 0.1% to 20%. In the present invention, the first crystal plane can be made approximately the same as the lattice constant of the second epitaxial layer, so that the difference in lattice constant between the first epitaxial layer and the second epitaxial layer can be easily achieved within the range of 0.1% to 20%.

[0018] In the present invention, when a conductive film is laminated on the insulating 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, a thickness of 100 nm or more can be preferably obtained. 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 insulating film, the laminated structure can be suitably used as an electrode substrate in which a crystalline conductive film is laminated on the insulating film.

[0019] 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. Examples of the cubic semiconductor include c-BN, c-AlN, c-GaN, c-InN, c-SiC, GaAs, AlAs, InAs, GaP, AlP, InP, and alloy semiconductors thereof. The thicknesses of the conductive film and the semiconductor film are not particularly limited, but are preferably 10 nm to 1000 μm, and more preferably 10 nm to 100 μm.

[0020] 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 the insulating 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 insulating film, allowing crystal growth.

[0021] In the present invention, it is preferable to form the insulating film by using oxygen atoms in the oxide film and then depositing the insulating film using oxygen gas. This film formation method can easily produce a laminate structure in which an epitaxial film containing a crystalline compound is deposited on a crystal substrate, and the laminate structure has, between the crystal substrate and the epitaxial film, an amorphous thin film containing a metal constituting the epitaxial film and / or the crystal substrate and a compound element of the crystalline compound, and / or one or more buried layers embedded in a portion of the crystal substrate and containing the metal constituting the epitaxial film and the compound element. In the present invention, it is preferable to have, between the crystal substrate and the epitaxial film, an amorphous thin film containing a metal constituting the epitaxial film and a compound element of the crystalline compound, and / or one or more buried layers embedded in a portion of the crystal substrate and containing the metal constituting the epitaxial film and the compound element, because this improves the crystallinity of the epitaxial film. Furthermore, in the present invention, it is preferable to have an amorphous thin film between the crystal substrate and the epitaxial film, the amorphous thin film containing the constituent metals of the epitaxial film and / or the crystal substrate and the compound element of the crystalline compound, and one or more buried layers embedded in a portion of the crystal substrate and containing the constituent metals and the compound element, since this further improves the functionality of the epitaxial film. Furthermore, in the present invention, it is preferable that the constituent metals contain Hf, since this further promotes stress relaxation and further enables multi-stage stress relaxation. Furthermore, in the present invention, it is preferable that the amorphous thin film have a thickness of 1 nm to 10 nm, since this further improves the crystallinity of the epitaxial film. An amorphous thin film with such a preferred thickness can be easily obtained by the preferred manufacturing method of the present invention. Furthermore, in the present invention, it is preferable that the buried layer have a cross-sectional shape that is approximately an inverted triangle, since this further improves the functionality of the epitaxial film. These preferred stacked structures are: This can be easily achieved by appropriately adjusting the thickness of the oxide film and the timing of introducing the oxygen gas.

[0022] 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.

[0023] The laminated structure obtained as described above can be used in a semiconductor device as is or after further processing, etc., according to a conventional method. When the laminated structure is used in a semiconductor device, it may be used as is, or other layers (e.g., an insulating layer, a semi-insulating layer, a conductor layer, a semiconductor layer, a buffer layer, or other intermediate layers) may be formed thereon. In the present invention, the laminated structure is preferably used as an SOI substrate in which a semiconductor film is stacked on the insulating film.

[0024] The 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 device. It may be a vertical device or a horizontal device, but in the present invention, the semiconductor device is preferably a horizontal device. 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 with Schottky gates (e.g., MESFETs) are preferred, MOSFETs and / or IGBTs are more preferred, and lateral MOSFETs and / or lateral IGBTs are most preferred.

[0025] 11 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 on a crystal substrate 29, and each element is provided on the insulating film 26a. The lateral IGBT of FIG. 11 has a gate electrode 21, an emitter electrode 22, a collector electrode 23, an insulating film 26, a p-type semiconductor 27, an n-type semiconductor 28, and an n-type semiconductor 29. -11 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. - 11 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.

[0026] 12 shows a preferred manufacturing process for the insulated gate bipolar transistor (IGBT) shown in FIG. 11. In the manufacturing process shown in FIG. 12, an insulating film 26a is formed on a crystal substrate 29, and an n-type insulating film 26a is formed on the insulating film 26a. - In FIG. 12(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. 12(b), the stacked structure of FIG. 12(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. 12(c), the stacked structure of FIG. 12(b) is polished using known means to obtain the stacked structure of FIG. 12(c). The obtained stacked structure is then subjected to various device fabrication processes using known means.

[0027] 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.

[0028] In addition to the above features, the semiconductor device of the present invention can be suitably used as a semiconductor device such as a power module, inverter, or converter by using known means, and further suitably used in a semiconductor system using a power supply device as the semiconductor device. The power supply device can be fabricated by connecting the semiconductor device to a wiring pattern or the like using known means. FIG. 13 shows an example of a power supply system. FIG. 13 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. 14 for use in a system device. FIG. 15 shows an example of a power supply circuit diagram for a power supply device. FIG. 15 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. 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]

[0029] 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 an insulating film made of a crystalline oxide on the Si substrate. Next, oxygen was introduced, the temperature was lowered, and the pressure was increased, and an insulating film was further formed by vapor deposition. The vapor deposition conditions for this film formation were as follows: Vapor deposition source: Hf, Zr Voltage: 3.5~4.75V Pressure: 3×10 -2 ~6×10 -2 Pa Substrate temperature: 450~700℃

[0030] Next, a platinum (Pt) metal film was formed as a conductive film on the insulating film by sputtering under the following conditions: Equipment: ULVAC sputtering equipment QAM-4 Pressure: 1.20×10 -1 Pa Target: Pt Power: 100W(DC) Thickness: 100nm Substrate temperature: 450~600℃

[0031] The resulting laminate structure contained an insulating film with good crystallinity. A cross-sectional STEM image of the resulting laminate structure is shown in FIG. 8. It can be seen from FIG. 8 that a regular peak-valley structure was formed at the interface between the insulating film and the conductive film, and that the angles formed by adjacent peaks and valleys in the peak-valley structure varied within a range of 30° to 45°. X-ray crystal lattice images of the conductive film are shown in FIGS. 9 and 10. It can be seen from FIGS. 9 and 10 that the resulting conductive film was defect-free and large-area, exhibiting excellent crystallinity, particularly in terms of electrode properties. The crystal substrate of the laminate structure, the single crystal film of the crystalline metal oxide, and the conductive film were analyzed for their respective crystallinity using an X-ray diffractometer. The results of XPS analysis are shown in FIG. 16. As is clear from FIG. 16, a (Hf,Zr)O film and a Pt single crystal film with good crystallinity were formed on the Si crystal substrate.

[0032] Example 2 A platinum (Pt) metal film was formed as a conductive film on a single crystal film of crystalline metal nitride in the same manner as in Example 1, except that nitrogen gas was used instead of oxygen gas. The crystal substrate of the stacked structure, the single crystal film of crystalline metal nitride, and the conductive film were then each measured using an X-ray diffractometer. Figure 17 shows the results of the XPS measurement. As is clear from Figure 17, a (Hf,Zr)N film and a Pt single crystal film with good crystallinity were formed on the Si crystal substrate. Furthermore, when measured using a four-terminal method, the resulting single crystal film of crystalline metal nitride had good conductivity.

[0033] The evaporation film-forming apparatus used in Example 1 is shown in Figure 18. The film-forming apparatus in Figure 18 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, Ar source 108, reactive gas source 109, power supply 110, substrate holder 111, substrate 112, cut filter 113, ICP ring 114, vacuum chamber 115, and rotation shaft 116. Note that the ICP electrodes 103a-103b in Figure 18 have a generally concave curved or parabolic shape curved toward the center of substrate 112.

[0034] As shown in FIG. 18, 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.

[0035] 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.

[0036] STEM analysis was performed on the stacked structure obtained in the same manner as in Example 1. The results are shown in FIGS. 19 to 21. FIG. 19 shows 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. 20 shows 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. FIG. 21 shows that the second amorphous layer contains Si from the crystalline substrate and Hf and Zr, which are constituent metals of the epitaxial layer 1001. FIG. 21 shows that the buried layer 1004 has a substantially inverted triangular cross section and is an oxide containing Hf and Si.

[0037] (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 present invention, unless otherwise specified, an SOI substrate or an SOI semiconductor device can be manufactured from the laminated structure using known means.

[0038] 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 on the insulating film 3 as a second epitaxial layer 4.

[0039] 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.

[0040] 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.

[0041] 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.

[0042] 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]

[0043] The layered structure of the present invention is suitable for use as an SOI substrate or an SOI semiconductor device. [Explanation of symbols]

[0044] 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 epitaxial layer 1002 First amorphous layer 1003 Second amorphous layer 1004 buried layer 1011 board

Claims

1. A stacked structure including an SOI substrate in which an insulating film containing a crystalline compound is stacked on a crystalline substrate, and a semiconductor film is further stacked on the insulating film, wherein the insulating film is characterized in that a compound element in a compound film stacked on the crystalline substrate is incorporated into the crystalline compound.

2. A laminated structure in which an epitaxial film, which is an insulating film containing a crystalline compound, is laminated on a crystal substrate, wherein a compound element in a compound film laminated on the crystal substrate is incorporated into the crystalline compound in the epitaxial film; A laminated structure having, between the crystal substrate and the epitaxial film, one or more amorphous thin films containing constituent metals of the epitaxial film and / or the crystal substrate and compound elements of the crystalline compound, and / or one or more embedded layers embedded in a portion of the crystal substrate and containing the constituent metals and the compound elements.

3. A laminated structure in which an epitaxial film, which is an insulating film containing a crystalline compound, is laminated on a crystal substrate, wherein a compound element in a compound film laminated on the crystal substrate is incorporated into the crystalline compound in the epitaxial film; A laminated structure having, between the crystal substrate and the epitaxial film, an amorphous thin film containing the constituent metal of the epitaxial film and the compound element, and / or one or more embedded layers embedded in a portion of the crystal substrate and containing the constituent metal of the epitaxial film and the compound element.

4. A laminated structure in which an epitaxial film, which is an insulating film containing a crystalline compound, is laminated on a crystal substrate, wherein a compound element in a compound film laminated on the crystal substrate is incorporated into the crystalline compound in the epitaxial film; A laminated structure having, between the crystal substrate and the epitaxial film, an amorphous thin film containing the constituent metals of the epitaxial film and / or the crystal substrate and the compound element, and one or more embedded layers embedded in a portion of the crystal substrate and containing the constituent metals and the compound element.

5. 5. The laminate structure according to claim 2, wherein the constituent metals include Hf.

6. 5. The laminated structure according to claim 2, wherein the amorphous thin film has a thickness of 1 nm to 10 nm.

7. 5. The laminated structure according to claim 2, wherein the buried layer has a cross-sectional shape of a substantially inverted triangle.

8. 5. The laminated structure according to claim 2, wherein the crystalline substrate is a crystalline Si substrate.

9. 5. The laminated structure according to claim 2, wherein the compound film contains the compound material of the crystal substrate.

10. 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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