Crystal, laminated structure, semiconductor device, electronic equipment, and system

Abstract

[Problem] The purpose of the present invention is to provide a crystal film and a laminated structure that have excellent crystallinity and are useful in a semiconductor device or the like. [Solution] A crystal film containing GeO2 as a main component is applied to, for example, a semiconductor device. The crystal film has a (111) orientation. The GeO2 has one or two crystal structures among tetragonal and orthorhombic crystal structures. Further, the crystal film has an area of 100 μm2 or more and a surface roughness of 10 nm or less, and is a single crystal film.

Description

Crystal, laminated structure, semiconductor device, electronic device and system

[0001] The present invention relates to a crystal and a layered structure useful for semiconductor devices.

[0002] Conventionally, Ga ２ O ３ is attracting attention as a promising ultra-wide bandgap (UWBG) semiconductor for future power electronics devices.

[0003] However, Ga ２ O ３ However, there are problems with the difficulty of producing p-type semiconductors, and it is not easy to make them inexpensive, so there are still many issues to be overcome before they can be widely used. In recent years, rutile germanium dioxide (r-GeO) has been developed as a new UWBG semiconductor (band gap 4.44-4.68 eV). ２ ) has been studied, and rutile germanium dioxide can be used as n-type and p-type semiconductors and can be produced inexpensively, so Ga ２ O ３ It is expected to be a UWBG semiconductor to replace r-TiO ２ r-GeO on (001) substrate ２ A laminated structure in which crystalline films are laminated has been studied (Non-Patent Document 1, Patent Document 1, Patent Document 2, and Patent Document 3). However, Non-Patent Document 2 was submitted as an erratum after the peer review of Non-Patent Document 1 (Non-Patent Document 2), and it was found that the crystal grains (abnormal grains) described in Non-Patent Document 1, Patent Document 1, Patent Document 2, and Patent Document 3 were rutile-type germanium dioxide crystals, and the remaining portions were amorphous phases. In other words, only an amorphous phase was formed in the majority, and even if a crystalline phase was formed, crystal grains were only formed in a portion. In addition, r-TiO ２ The (001) substrate was expensive and other problems remained, and it was still not satisfactory. ２ The (001) substrate has the problem of poor heat dissipation, so there has been a long-awaited need for a method to produce crystals with excellent crystallinity and to produce crystals on substrates with excellent heat dissipation.

[0004] Takane, K. Kaneko, “Establishment of a growth route of crystallized rutile GeO2 thin film (≧ 1 mm / h) and its structural “Applied Physics Letters Vol. 119, pp. 062104(1-6) (2021). Takane, K. Kaneko, Erratum: “Establishment of a growth route of crystallized rutile GeO2 thin film (≧1 μm / h) and its “structural properties” Applied Physics Letters Vol. 120, 099903(1-3) (2022).

[0005] International Publication No. 2023 / 008454 International Publication No. 2023 / 008453 International Publication No. 2023 / 008452

[0006] An object of the present invention is to provide a crystalline film and a layered structure having excellent crystallinity that are useful for semiconductor devices and the like.

[0007] As a result of intensive research into achieving the above object, the present inventors have newly developed a mist CVD apparatus using a guide partition, and have used the mist CVD apparatus using the guide partition to produce GeO ２ The inventors have succeeded in creating a crystalline film containing as a main component a crystalline film characterized by a (111) orientation, and have found that the obtained crystal can be easily produced at low cost, has excellent crystallinity, and is useful for semiconductor devices, etc., and have discovered that such a crystalline film can solve all of the above-mentioned conventional problems at once. Furthermore, after obtaining the above-mentioned findings, the inventors have conducted further research and have completed the present invention.

[0008] That is, the present invention relates to the following inventions: [1] GeO ２A crystalline film containing as a main component, characterized in that it is (111) oriented. [2] The crystalline film according to [1] above, which has a tetragonal or orthorhombic crystal structure. [3] The crystalline film according to [1] above, which has a tetragonal crystal structure. [4] The crystalline film according to [1] above, which has an orthorhombic crystal structure. [5] 100 μm ２ [6] The crystal film according to [1] above, having an area of ​​1 μm or more. [7] The crystal film according to [1] above, having a thickness of 1 μm or more. [8] The crystal film according to [1] above, having a surface roughness of 10 nm or less. [9] The crystal film according to [1] above, which is a single crystal film.

[10] A crystal film according to [1] above, which is formed by depositing GeO directly or via another layer on a crystal substrate. ２

[10] A laminated structure according to [9], wherein the crystal substrate and / or the crystal film are semiconductors.

[11] The GeO ２ The crystalline film according to [9] above, wherein the GeO has one or two types of tetragonal or orthorhombic crystal structures. ２

[13] The crystalline film according to [9], wherein the GeO has a tetragonal crystal structure. ２

[14] The crystal film according to [9], wherein the crystal film has an orthorhombic crystal structure. ２The laminate structure according to [9], having an area of ​​at least 1 μm.

[15] The laminate structure according to [9], wherein the crystal film has a thickness of 1 μm or more.

[16] The laminate structure according to [9], wherein the crystal film has a surface roughness of 10 nm or less.

[17] The laminate structure according to [9], wherein the crystal substrate contains silicon or a silicon-containing compound as a main component.

[18] The laminate structure according to [9], wherein the crystal substrate is Si or SiC.

[19] The laminate structure according to [9], wherein the crystal film is a single crystal film.

[20] A laminate structure in which a crystal film is stacked, directly or via another layer, on a crystal substrate whose surface contains silicon or a silicon-containing compound as a main component on part or all of its surface, wherein part or all of the surface has a (111) orientation and the crystal film contains a metal oxide containing germanium as a main component.

[21] The laminate structure according to claim 20, wherein the crystal film has a tetragonal, orthorhombic, or trigonal crystal structure.

[22] A laminate structure in which a crystalline film containing a Ge-containing metal oxide as a main component is laminated on a crystalline substrate directly or via another layer, wherein the thermal conductivity of the crystalline substrate and / or the other layer is 100 W / mK or more.

[23] A laminate structure in which a crystalline film is laminated on a crystalline substrate directly or via another layer, wherein the crystalline substrate or the other layer contains a metal or metal compound containing a d-block element and / or a p-block element of the periodic table as a main component and has a cubic crystal structure, and the crystalline film contains a Ge-containing metal oxide as a main component.

[24] A laminate structure in which a crystalline film containing GeO is laminated on a crystalline substrate directly or via another layer, wherein the crystalline film contains a metal or metal compound containing a d-block element and / or a p-block element of the periodic table as a main component and has a cubic crystal structure. ２A laminate structure having a crystalline film laminated thereon, the crystalline substrate or the other layer containing a carbon-containing compound as a main component.

[25] A laminate structure having a crystalline film laminated directly or via another layer on a crystalline substrate containing silicon or a silicon-containing compound as a main component on part or all of its surface, the laminate structure being characterized in that part or all of the surface has a (100) orientation and the crystalline film contains a metal oxide containing germanium as a main component.

[26] A laminate structure having a crystalline film laminated directly or via another layer on a crystalline substrate, the crystalline substrate or the other layer having a (100) orientation and the crystalline film having a (111) orientation.

[27] The laminate structure according to

[26] , wherein the crystalline film contains germanium.

[28] The laminate structure according to

[26] , wherein the crystalline film contains a compound containing germanium as a main component.

[29] The laminate structure according to

[26] , wherein the crystalline film has one or two types of tetragonal or orthorhombic crystal structures.

[30] A semiconductor device including a crystalline film or a laminated structure, wherein the crystalline film is the crystalline film according to claim 1, and the laminated structure is the laminated structure according to [9],

[20] ,

[22] ,

[23] ,

[24] ,

[25] , or

[26] .

[31] The semiconductor device according to

[30] , which is a power device.

[32] The semiconductor device according to

[30] , which is a Schottky barrier diode (SBD), a junction barrier Schottky diode (JBS), a high electron mobility transistor (HEMT), a metal oxide semiconductor field effect transistor (MOSFET), a junction field effect transistor (JFET), an insulated gate bipolar transistor (IGBT), or a light emitting diode (LED).

[33] An electronic device including a semiconductor device, wherein the semiconductor device is the semiconductor device according to

[30] .

[34] A system including an electronic device, wherein the electronic device is the electronic device according to

[33] .

[0009] The crystal and layered structure of the present invention are useful for semiconductor devices and the like, and exhibit excellent crystallinity.

[0010] FIG. 1 is an example of a schematic configuration diagram of a film forming apparatus preferably used in the present invention. FIG. 2 is a diagram schematically showing an atomization apparatus preferably used in the present invention. FIG. 3 is a diagram showing the results of 2θ / ω in the XRD diffraction results in Example 1. FIG. 4 is a diagram showing an AFM image in Example 1. FIG. 5 is a diagram showing an SEM image in Example 1. FIG. 6 is a diagram showing an EDS image in Example 1. FIG. 7 is a diagram showing the results of 2θ / ω in the XRD diffraction results in Example 2. FIG. 8 is a diagram showing an SEM image in Example 2. FIG. 9 is a diagram showing the results of 2θ / ω in the XRD diffraction results in Example 3. FIG. 10 is a diagram schematically showing a preferred example of a Schottky barrier diode (SBD) of the present invention. FIG. 11 is a diagram schematically showing a preferred example of a high electron mobility transistor (HEMT) of the present invention. FIG. 12 is a diagram schematically showing a preferred example of a metal oxide semiconductor field effect transistor (MOSFET) of the present invention. FIG. 13 is a diagram schematically showing a preferred example of a junction field effect transistor (JFET) of the present invention. FIG. 14 is a diagram schematically showing a preferred example of an insulated gate bipolar transistor (IGBT) of the present invention. FIG. 1 is a diagram schematically showing a preferred example of a light-emitting element (LED) of the present invention. FIG. 2 is a diagram schematically showing a preferred example of a junction barrier Schottky diode (JBS) of the present invention. FIG. 3 is a diagram schematically showing a cross-sectional side view of an atomization device preferably used in the present invention. FIG. 4 is a diagram showing the results of 2θ / ω in the XRD diffraction results in Example 4. FIG. 5 is a diagram showing the results of 2θ / ω in the XRD diffraction results in Example 5. FIG. 6 is a diagram showing the results of 2θ / ω in the XRD diffraction results in Example 6. FIG. 7 is a diagram showing the results of 2θ / ω in the XRD diffraction results in Example 8.

[0011] The crystal of the present invention is GeO ２ The laminated structure of the present invention is a crystalline film containing GeO as a main component and characterized by being (111) oriented. ２The present invention also provides a laminated structure in which a crystalline film containing as a main component is laminated, characterized in that the crystalline substrate and the crystalline film have a (111) orientation. The present invention also provides a laminated structure in which a crystalline film is laminated directly or via another layer on a crystalline substrate whose surface contains silicon or a silicon-containing compound as a main component, in part or all of the surface, wherein the crystalline substrate and / or the other layer have a (111) orientation, and the crystalline film contains as a main component a metal oxide containing germanium. The present invention also provides a laminated structure in which a crystalline film is laminated directly or via another layer on a crystalline substrate, characterized in that the crystalline substrate or the other layer has a (100) orientation, and the crystalline film has a (111) orientation. In the present invention, the crystalline film preferably contains germanium, and more preferably contains a compound containing germanium as a main component. By setting the crystalline film in this preferred range, a crystalline film with better electrical properties can be achieved. The compound is preferably an oxide, but may also be a nitride, oxynitride, carbide, or sulfide. "Oriented" refers to a state in which, for example, a crystal plane represented by the (100) or (111) plane is aligned in a specific direction. In this specification, "film" can be interpreted as "layer." A "laminated structure" refers to a structure including one or more crystal layers, and may also include layers other than the crystal layer (e.g., an amorphous layer). The crystal layer is preferably a single crystal layer, but may also be a polycrystalline layer. In this specification, the orientation state can be confirmed by X-ray diffraction. More specifically, for example, when the crystal film is oriented in the (111) plane, it can be determined that the crystal film is oriented in the (111) plane if the integrated intensity ratio of the peak derived from the (111) plane to the peak derived from other crystal planes is larger than the integrated intensity ratio of the peak derived from the (111) plane to the peak derived from other crystal planes of the same randomly oriented crystal.

[0012] The laminated structure of the present invention is also characterized in that a crystal film containing a Ge-containing metal oxide as a main component is laminated on a crystal substrate directly or via another layer, and the crystal substrate and / or the other layer have a thermal conductivity of 100 W / mK or more. The term "main component" in the present invention means that the content of the germanium-containing metal oxide or the Ge-containing metal oxide in the crystal film is 50% or more in terms of composition ratio in the crystal film. In an embodiment of the present invention, GeO in the crystal film is ２ The content of silicon or silicon-containing compounds in the crystal film is preferably 70% or more, more preferably 90% or more, in terms of composition ratio in the crystal substrate. Furthermore, the content of silicon or silicon-containing compounds in the crystal substrate is 50% or more, in terms of composition ratio in the crystal substrate. In an embodiment of the present invention, the content of silicon or silicon-containing compounds in the crystal substrate is preferably 70% or more, more preferably 90% or more, in terms of composition ratio in the crystal substrate. According to such a preferred range, semiconductor properties and heat dissipation properties can be improved. Another feature is a layered structure in which a crystal film is layered on a crystal substrate directly or via another layer, wherein the crystal substrate or the other layer contains, as a main component, a metal or metal compound containing a d-block element and / or a p-block element of the periodic table and has a cubic crystal structure, and the crystal film contains, as a main component, a metal oxide containing Ge. Examples of the d-block elements include scandium (Sc), titanium (Ti), vanadium (V), chromium (Cr), manganese (Mn), iron (Fe), cobalt (Co), nickel (Ni), copper (Cu), zinc (Zn), yttrium (Y), zirconium (Zr), niobium (Nb), molybdenum (Mo), technetium (Tc), ruthenium (Ru), rhodium (Rh), palladium (Pd), cadmium (Cd), hafnium (Hf), tantalum (Ta), tungsten (W), rhenium (Re), osmium (Os), iridium (Ir), platinum (Pt), and gold (Au). Examples of the p-block elements include aluminum (Al), silicon (Si), gallium (Ga), indium (In), tin (Sn), and antimony (Sb).

[0013] Also, GeO is deposited on the crystal substrate directly or through another layer. ２ Another feature is a laminated structure in which a crystalline film containing as a main component is laminated, and the crystalline substrate or the other layer contains a carbon-containing compound as a main component. In an embodiment of the present invention, it is preferable that the crystalline substrate or the other layer contains a carbon-containing compound as a main component. It is also preferable that the crystalline substrate or the other layer contains SiC. Examples of substrates containing a carbon-containing compound as a main component include diamond and SiC. Within such a preferred range, better heat dissipation properties can be achieved.

[0014] The "main component" in the present invention is GeO in the crystal film. ２ In an embodiment of the present invention, the content of GeO in the crystal film is 50% or more in terms of composition ratio. ２ The content of GeO in the present invention is preferably 70% or more, more preferably 90% or more, in terms of composition ratio in the crystal film. ２ is the GeO ２ has one or two types of tetragonal or orthorhombic crystal structure, and ２ More preferably, the GeO has a tetragonal crystal structure. ２ It is also more preferable that the crystal film has an orthorhombic crystal structure. According to such a preferred range, the semiconductor properties can be improved. Furthermore, the crystal film may contain a metal other than germanium. Examples of the other metal include metals in Group 14 of the periodic table other than germanium (such as tin or silicon) and metals in Group 4 of the periodic table (such as titanium, zirconia, or hafnium). The atomic ratio of germanium among the metal elements in the crystal film is preferably 0.5 or more. By setting the atomic ratio of germanium within such a preferred range, a crystal film with better semiconductor properties can be realized.

[0015] In the present invention, the area of ​​the crystal is 100 μm ２ It is preferable that the area is 100 mm or more. ２It is more preferable that the area is within the above range. If the area is within these preferable ranges, the breakdown voltage of the semiconductor film can be improved.

[0016] The above-described preferred crystalline film and laminated structure can be more easily obtained, for example, by using the film-forming apparatus shown in FIG. 1 . Furthermore, the surface roughness (RMS) of the crystalline film is not particularly limited as long as it is 10 nm or less, but in an embodiment of the present invention, it is preferably 1 nm or less. In the present invention, the crystalline film is preferably a single-crystal film. Furthermore, the thickness of the crystalline film is not particularly limited as long as it does not impede the object of the present invention, but in the present invention, it is preferably 0.3 μm or more, and more preferably 1 μm or more. By achieving such a preferred thickness or surface roughness, when the crystalline film or the laminated structure is applied to a semiconductor device, the semiconductor device can be endowed with superior electrical properties such as voltage resistance. The surface roughness (RMS) refers to a value calculated based on JIS B0601 using the surface profile measurement results of a 1 μm square area using an atomic force microscope (AFM).

[0017] Furthermore, the crystal substrate is not particularly limited as long as it does not impede the objectives of the present invention, and may be a known substrate, an insulating substrate, a conductive substrate, or a semiconductor substrate. However, in the present invention, a semiconductor substrate is preferred. According to such a preferred range, the semiconductor characteristics can be improved. The crystal substrate may be a single crystal substrate or a polycrystalline substrate. The crystal substrate may also be a substrate having a metal film on its surface. When the crystal substrate is a conductive substrate, a vertical device can be fabricated without removing the substrate. The crystal structure of the crystal substrate is also not particularly limited as long as it does not impede the objectives of the present invention. Examples of the crystal structure of the crystal substrate include a hexagonal crystal structure, a cubic crystal structure, and a tetragonal crystal structure. Examples of crystal substrates having a hexagonal crystal structure include a GaN substrate, a SiC substrate, and a sapphire substrate (e.g., a-plane sapphire, c-plane sapphire, m-plane sapphire, and r-plane sapphire substrate). Examples of crystal substrates having a tetragonal crystal structure include GeO. ２ Substrate, SrTiO３ Substrate, TiO ２ Substrate or MgF ２ Examples of suitable substrates include a substrate having a cubic crystal structure, such as a Si substrate or a SiC substrate. In an embodiment of the present invention, the crystalline substrate, the other layer, and / or the crystalline film are preferably semiconductors. This preferred range can improve the semiconductor characteristics when applied to a semiconductor device. It is more preferable that the crystalline substrate contains silicon or a silicon-containing compound as a main component. This preferred range can improve heat dissipation. Examples of suitable substrates containing silicon or a silicon-containing compound as a main component include a Si substrate or a SiC substrate. The Si substrate may be a conductive substrate containing a dopant such as phosphorus (P), arsenic (As), antimony (Sb), or boron (B). The SiC substrate may be a conductive substrate containing a dopant such as phosphorus (P), boron (B), or the like. The crystalline substrate may have an off-axis angle, specifically, for example, between 0.1° and 10°. Within such a preferred range, the ease of manufacture can be further improved, the crystallinity can be improved, the heat dissipation properties can be improved, and the material can be more easily applied to semiconductor devices and the like.

[0018] In the present invention, a film may be formed directly on the substrate, or other layers such as a layer different from the oxide semiconductor (for example, an n-type semiconductor layer, an n+ type semiconductor layer, an n- type semiconductor layer, etc.), an insulator layer (including a semi-insulator layer), or a buffer layer may be stacked on the substrate, and then the film may be formed on the substrate via the other layers. In particular, a buffer layer can be suitably used to reduce the difference in lattice constant between the crystal substrate and the oxide crystal. Examples of materials constituting the buffer layer include SnO ２ , TiO ２ , V.O. ２ , MnO ２ , RuO ２ , CsO ２ , IrO ２ , GeO ２ , CuO ２ , PbO ２ , AgO２ , CrO ２ , SiO ２ , SiC, GaN, and mixed crystals thereof.

[0019] The crystalline film is formed by using, for example, the film-forming apparatus shown in FIG. ２ By forming a crystalline film and its mixed crystal film, it can be obtained more easily. Furthermore, doping can also be performed appropriately using the film forming apparatus. The doped crystal can be suitably used as a semiconductor film or semiconductor layer, and n-type or p-type dopants can be applied by conventional doping methods for oxide semiconductors. Examples of n-type dopants include antimony (Sb), arsenic (As), bismuth (Bi), phosphorus (P), fluorine (F), niobium (Nb), vanadium (V), tantalum (Ta), and tungsten (W). Examples of p-type dopants include aluminum (Al), gallium (Ga), and indium (In). The present invention also encompasses stacked structures obtained in this manner.

[0020] The crystal film or the laminated structure can be used as is or after known processing such as substrate peeling, using known means, for example, in semiconductor devices. Examples of such semiconductor devices include Schottky barrier diodes (SBDs), junction barrier Schottky diodes (JBSs), high electron mobility transistors (HEMTs), metal oxide semiconductor field effect transistors (MOSFETs), junction field effect transistors (JFETs), insulated gate bipolar transistors (IGBTs), and light-emitting diodes (LEDs). These semiconductor devices can also be used in modules incorporating these semiconductor devices, electronic devices incorporating these semiconductor devices, and their components. These devices are useful for a variety of applications, particularly power devices. Semiconductor devices can be classified into horizontal devices (horizontal devices) in which an electrode is formed on one side of a semiconductor layer, and vertical devices (vertical devices) in which electrodes are formed on both the front and back sides of a semiconductor layer. In the present invention, the semiconductor device can be used in both horizontal and vertical devices.

[0021] Examples of semiconductor devices that can be suitably used in the present invention will be described in more detail below with reference to the drawings, but the present invention is not limited to these examples. ２ A preferred example of a crystal layer containing the above as a main component as a semiconductor layer is shown below.

[0022] 11 shows a preferred example of a Schottky barrier diode (SBD) including an n-type semiconductor layer 101a, an n+ type semiconductor layer 101b, a p-type semiconductor layer 102, a metal layer 103, an insulator layer 104, a Schottky electrode 105a, and an ohmic electrode 105b. The metal layer 103 is made of a metal such as Al, and covers the Schottky electrode 105a.

[0023] FIG. 12 shows a preferred example of a high electron mobility transistor (HEMT) including an n-type semiconductor layer 121 a having a wide band gap, an n-type semiconductor layer 121 b having a narrow band gap, an n+ type semiconductor layer 121 c, a p-type semiconductor layer 123, a gate electrode 125 a, a source electrode 125 b, a drain electrode 125 c, and a substrate 129.

[0024] 13 shows a preferred example of a metal oxide semiconductor field effect transistor (MOSFET) including an n-type semiconductor layer 131a, a first n+ type semiconductor layer 131b, a second n+ type semiconductor layer 131c, a p-type semiconductor layer 132, a p+ type semiconductor layer 132a, a gate insulating film 134, a gate electrode 135a, a source electrode 135b, and a drain electrode 135c. Note that the p+ type semiconductor layer 132a may be a p-type semiconductor layer or may be the same as the p-type semiconductor layer 132.

[0025] FIG. 14 shows a preferred example of a junction field effect transistor (JFET) including an n-type semiconductor layer 141a, a first n+ type semiconductor layer 141b, a second n+ type semiconductor layer 141c, a p-type semiconductor layer 142, a gate electrode 145a, a source electrode 145b, and a drain electrode 145c.

[0026] FIG. 15 shows a preferred example of an insulated gate bipolar transistor (IGBT) including an n-type semiconductor layer 151, an n-type semiconductor layer 151a, an n+ type semiconductor layer 151b, a p-type semiconductor layer 152, a gate insulating film 154, a gate electrode 155a, an emitter electrode 155b, and a collector electrode 155c.

[0027] (LED) An example of a semiconductor device of the present invention that is a light-emitting diode (LED) is shown in Figure 16. The semiconductor light-emitting device of Figure 16 has an n-type semiconductor layer 161 on a second electrode 165b, and a light-emitting layer 163 is stacked on the n-type semiconductor layer 161. A p-type semiconductor layer 162 is stacked on the light-emitting layer 163. A translucent electrode 167 that transmits light generated by the light-emitting layer 163 is provided on the p-type semiconductor layer 162, and a first electrode 165a is stacked on the translucent electrode 167. The semiconductor light-emitting device of Figure 16 may be covered with a protective layer except for the electrode portion.

[0028] Examples of materials for the translucent electrode include conductive oxide materials containing indium (In) or titanium (Ti). ２ O ３ , ZnO, SnO ２ , Ga ２ O ３ , TiO ２ , CeO ２ Alternatively, a mixed crystal of two or more of these materials or a doped material thereof may be used. A translucent electrode can be formed by applying these materials by a known method such as sputtering. After the formation of the translucent electrode, thermal annealing may be performed to make the translucent electrode transparent.

[0029] In the semiconductor light-emitting element of FIG. 16, the first electrode 165a is a positive electrode and the second electrode 165b is a negative electrode, and current is passed through these electrodes to the p-type semiconductor layer 162, the light-emitting layer 163, and the n-type semiconductor layer 161, causing the light-emitting layer 163 to emit light.

[0030] Examples of materials for the first electrode 165a and the second electrode 165b include metals such as Al, Mo, Co, Zr, Sn, Nb, Fe, Cr, Ta, Ti, Au, Pt, V, Mn, Ni, Cu, Hf, W, Ir, Zn, In, Pd, Nd, and Ag, or alloys thereof; conductive metal oxide films such as tin oxide, zinc oxide, indium oxide, indium tin oxide (ITO), and indium zinc oxide (IZO); organic conductive compounds such as polyaniline, polythiophene, and polypyrrole; and mixtures thereof. The method for forming the electrodes is not particularly limited, and they can be formed on the substrate according to a method appropriately selected from wet methods such as printing, spraying, and coating; physical methods such as vacuum deposition, sputtering, and ion plating; and chemical methods such as CVD and plasma CVD, taking into consideration their suitability for the material.

[0031] FIG. 17 shows the main components of a junction barrier Schottky diode (JBS) according to a preferred embodiment of the present invention. The JBS shown in FIG. 17 includes an ohmic electrode 1020, an n-type semiconductor layer 1010a, an n+-type semiconductor layer 1010b, a Schottky electrode 1030, and an electric field relaxation region 1060. The Schottky electrode 1030 is composed of metal layers 1030a, 1030b, and 1030c. In the semiconductor device shown in FIG. 17, the outer ends of metal layers 1030a and / or 1030b serving as second electrode layers are located outside the outer end of metal layer 1030c serving as a first electrode layer. In the semiconductor device shown in FIG. 17, the electric field relaxation region 1060 includes at least two electric field relaxation regions 1060 in a plane including at least a portion of the second electrode layer located outside the outer end of the first electrode layer and the outer end of the second electrode. In the semiconductor device of FIG. 17, the electric field relaxation region 1060 is made of a p-type semiconductor, and forms a PN junction with the n-type semiconductor layer 1010a.

[0032] 17 may be formed by any known method without particular limitation, as long as it does not impede the object of the present invention, such as forming a film by vacuum deposition, CVD, sputtering, or various coating techniques, followed by patterning by photolithography, or directly patterning by printing or the like.

[0033] Example 1 Figure 1 is a diagram showing an example of a preferred embodiment of a film production apparatus when the atomization device of the present invention is used as a film production atomization table. The film production apparatus 19 is composed of a film-forming sample 20, a sample stage 21, a carrier gas source 22a, a carrier gas source 22b, a flow rate control valve 23a, a flow rate control valve 23b, a film production chamber 27, a heater 28, and an atomization device 30. The atomization device 30 is composed of a raw material partition 24, a raw material liquid to be atomized 24a, an ultrasonically transparent substrate 24b, a stage 24c, an ultrasonic vibrator 26, a guide partition 31, an ultrasonic transmission liquid tank 35, and an ultrasonic transmission liquid 36. Figure 2 is a diagram showing another preferred embodiment of a film production apparatus when the atomization device of the present invention is used as a film production atomization table. The atomization device 30 is composed of a raw material partition wall 24, a raw material liquid for atomization 24a, an ultrasonically transparent substrate 24b, a base 24c, an ultrasonic vibrator 26, a guide partition wall 31, an ultrasonic transmission liquid tank 35, and an ultrasonic transmission liquid 36. The sample stage 21 is made of quartz, and the surface on which the film-forming sample 20 is placed is inclined from the horizontal. By fabricating both the film-forming chamber 27 and the sample stage 21 from quartz, impurities originating from the device are prevented from being mixed into the crystalline film formed on the film-forming sample 20. The raw material liquid for atomization 24a is contained in the mist generating source 24. The guide partition wall 31 is in contact with the ultrasonically transparent substrate 38. Figure 18 is a schematic cross-sectional side view of the atomization device used in the present invention. The atomization device 30 in Figure 18 is composed of a raw material partition wall 24, an ultrasonically transparent substrate 24b, a base 24c, an ultrasonic vibrator 26, a guide partition wall 31, and an ultrasonic transmission liquid tank 35. The guide partition 31 is in contact with the ultrasonic wave transmission liquid tank 35. By using the guide partition 31, the ultrasonic waves generated by the ultrasonic vibrator 26 are transmitted to the raw material partition 24 more efficiently.

[0034] Next, as the film formation sample 20, a 10 mm square Si(111) substrate on which a 900 nm average thickness 3C-SiC(111) thin film was laminated was placed on the sample stage 21, and the heater 28 was operated to raise the temperature inside the film formation chamber 27 to 750°C. Next, the flow rate control valve 23 was opened to supply carrier gas from the carrier gas source 22 into the film formation chamber 27. After the atmosphere inside the film formation chamber 27 was sufficiently replaced with the carrier gas, the flow rate of the carrier gas was adjusted to 3 L / min. Oxygen gas was used as the carrier gas.

[0035] Next, the ultrasonic vibrator 26 was vibrated at 3.0 MHz, and the vibration was propagated to the atomization raw material liquid 24a through the ultrasonic transmitter 25a, thereby atomizing the atomization raw material liquid 24a to generate raw material fine particles. These raw material fine particles were introduced into the film formation chamber 27 by the carrier gas, reacted in the film formation chamber 27, and formed tetragonal GeO on the film formation sample 20 by a CVD reaction on the film formation surface of the film formation sample 20. ２ A crystal film having a thickness of 1.2 μm was formed.

[0036] The obtained GeO ２ The crystalline film was measured using an X-ray diffractometer. Figure 3 shows the 2θ / ω results from the XRD diffraction. As is clear from Figure 3, the obtained crystalline film is GeO with a tetragonal rutile structure oriented in (111). ２ The half-width of 2θ-ω was 68 arcsec, and GeO with good crystallinity was grown on a 3C-SiC(111) thin film grown on a Si(111) substrate. ２ A crystalline film was formed.

[0037] The obtained GeO ２ When the surface of the crystal film was observed using an atomic force microscope (AFM), it was found that the surface roughness (RMS) based on JIS B0601 was 0.26 nm, as shown in FIG. 4, indicating excellent surface smoothness.

[0038] The obtained GeO ２The surface of the crystalline film was observed using an SEM. The SEM image is shown in Figure 5. As is clear from Figure 5, the GeO film has excellent surface smoothness and good crystallinity. ２ The surface of the obtained crystalline film was evaluated using EDS, and as shown in FIG. ２ It was found that the pores were formed over an area of ​​more than 100m.

[0039] (Example 2) Film formation was carried out in the same manner as in Example 1, except that a Si (100) substrate was used as the substrate. The obtained crystalline film was measured using an X-ray diffractometer. Figure 7 shows the 2θ / ω results from the XRD diffraction results. As is clear from Figure 7, the obtained crystalline film was GeO having a (111)-oriented tetragonal rutile structure. ２ The film was a single crystal. GeO with good crystallinity on a Si(100) substrate. ２ Crystals were formed. The film thickness was 1.5 μm.

[0040] The surface of the obtained crystalline film was observed using an SEM. The SEM image is shown in Figure 8. As is clear from Figure 8, the GeO film had excellent surface smoothness and good crystallinity. ２ The surface of the obtained crystalline film was evaluated using EDS, and as shown in FIG. ２ It was found that the pores were formed over an area of ​​more than 100m.

[0041] (Example 3) Film formation was carried out in the same manner as in Example 1, except that the film formation temperature was set to 725°C. The obtained crystalline film was measured using an X-ray diffractometer. Figure 10 shows the 2θ / ω results from the XRD diffraction results. As is clear from Figure 10, the obtained crystalline film was GeO containing (111)-oriented tetragonal and orthorhombic crystals. ２ The GeO film with good crystallinity was grown on a 3C-SiC(111) thin film on a Si(111) substrate. ２ Crystals were formed. The film thickness was 1.3 μm.

[0042] (Example 4) Film formation was carried out in the same manner as in Example 1, except that the substrate was an r-TiO2 (111) substrate, the film formation temperature was set to 700°C, and the flow rate of the supplied gas was reduced. The obtained crystalline film was measured using an X-ray diffractometer. Figure 19 shows the 2θ / ω results of the XRD diffraction results. As is clear from Figure 19, the obtained crystalline film was composed of GeO containing tetragonal crystals oriented in (111). ２ The GeO film was crystalline. ２ Crystals were formed. The film thickness was 1.1 μm.

[0043] (Example 5) A crystalline film was obtained in the same manner as in Example 1, except that the film formation temperature was set to 800°C. The 2θ / ω results of the XRD diffraction results of the obtained crystalline film are shown in Figure 20. As is clear from Figure 20, the obtained crystalline film was a GeO2 crystalline film having orthorhombic, tetragonal, and trigonal crystal structures. The film thickness was 1.4 μm.

[0044] (Example 6) Film formation was carried out in the same manner as in Example 1, except that a Si(100) substrate on which a 3C-SiC(100) thin film had been grown was used. The obtained crystalline film was measured using an X-ray diffractometer. Figure 21 shows the 2θ / ω results of the XRD diffraction. As is clear from Figure 21, the obtained crystalline film was composed of (111)-oriented orthorhombic GeO ２ The film was a single crystal. GeO with good crystallinity on a Si(100) substrate. ２ A crystalline film was formed, with a thickness of 1.5 μm.

[0045] (Example 7) A Si (100) substrate was used, and the concentration of antimony chloride was adjusted to 3 mol % relative to the germanium dioxide raw material concentration in the atomization raw material solution 24a. Film formation was carried out in the same manner as in Example 1, except that the film formation temperature was set to 750°C, nitrogen gas was used as the carrier gas, and the flow rate of the carrier gas was reduced. The result of 2θ / ω by XRD diffraction measurement of the obtained crystalline film is shown in Figure 22. The obtained crystalline film was GeO having a trigonal crystal structure. ２ The film was a single crystal. GeO with good crystallinity on a Si(100) substrate.２ The film thickness was 2.2 μm.

[0046] (Example 8) Film formation was carried out in the same manner as in Example 7, except that a Si (111) substrate was used. The 2θ / ω results of the obtained crystalline film by XRD diffraction measurement are shown in FIG. 23. The obtained crystalline film was GeO ２ The GeO film was a single crystal film with good crystallinity on a Si(111) substrate. ２ The film thickness was 2.2 μm.

[0047] (Test Example 1) Example 1 of the present invention was heated at 850°C for 20 minutes, and then the temperature change was measured in the atmosphere using a radiation thermometer "TMHX-CGE2400-0300H4.5". As a result, the surface temperature of Example 1 was 50°C 20 seconds after it was taken out into the atmosphere, and the surface temperature was 45°C 30 seconds after it was taken out. ２ r-GeO on (001) substrate ２ Measurements were taken using a (001) crystal grown, and the surface temperature was 290° C. 20 seconds after it was taken out into the air, 77° C. after 30 seconds, and 45° C. after 90 seconds. These results show that Example 1 of the present invention has superior heat dissipation properties.

[0048] The crystal film and laminated structure of the present invention are suitable for use in, for example, semiconductor devices.

[0049] 19 Film forming apparatus 20 Film forming sample 21 Sample stage 22a Carrier gas source 22b Dilution gas source 23a Flow rate control valve 23b Flow rate control valve 24 Raw material partition 24a Raw material liquid for atomization 24b Ultrasonic transmitting substrate 24c Stand 26 Ultrasonic vibrator 27 Film forming chamber 28 Heater 30 Atomization device 31 Guide partition 33 Dilution gas supply pipe 34 Carrier gas supply pipe 35 Ultrasonic transmitting liquid tank 36 Ultrasonic transmitting liquid 37 Film forming chamber 101a n-type semiconductor layer 101b n+ type semiconductor layer 102 p-type semiconductor layer 103 Metal layer 104 Insulator layer 105a Schottky electrode 105b Ohmic electrode 111a n-type semiconductor layer 111b n+ type semiconductor layer 114 Semi-insulating layer 115a Gate electrode 115b Source electrode 115c Drain electrode 118 Buffer layer 121a Wide band gap n-type semiconductor layer 121b Narrow band gap n-type semiconductor layer 121c N+ type semiconductor layer 123 P-type semiconductor layer 124 Semi-insulating layer 125a Gate electrode 125b Source electrode 125c Drain electrode 128 Buffer layer 129 Substrate 131a N- type semiconductor layer 131b First n+ type semiconductor layer 131c Second n+ type semiconductor layer 132 P-type semiconductor layer 134 Gate insulating film 135a Gate electrode 135b Source electrode 135c Drain electrode 138 Buffer layer 139 Semi-insulating layer 141a N- type semiconductor layer 141b First n+ type semiconductor layer 141c Second n+ type semiconductor layer 142 P type semiconductor layer 145a Gate electrode 145b Source electrode 145c Drain electrode 151 N type semiconductor layer 151a n- type semiconductor layer 151b n+ type semiconductor layer 152 P type semiconductor layer 154 Gate insulating film 155a Gate electrode 155b Emitter electrode 155c Collector electrode 161 N type semiconductor layer 162 P type semiconductor layer 163 Light emitting layer 165a First electrode 165b Second electrode 167 Light-transmitting electrode 169 Substrate 1010a N- type semiconductor 1010b N+ type semiconductor 1020 Ohmic electrode 1030 Schottky electrode 1030a Metal layer 1030b Metal layer 1030c Metal layer 1060 Electrolytic relaxation region

Claims

1. GeO ２ A crystalline film comprising as a main component thereof a (111) oriented crystalline film.

2. The crystal film according to claim 1, which has a tetragonal or orthorhombic crystal structure.

3. The crystal film according to claim 1, which has a tetragonal crystal structure.

4. The crystal film according to claim 1, which has an orthorhombic crystal structure.

5. 100μm ２ 2. The crystal film according to claim 1, having an area of ​​at least 100 nm.

6. The crystal film according to claim 1, having a thickness of 1 μm or more.

7. The crystal film according to 1 above, having a surface roughness of 10 nm or less.

8. The crystalline film according to claim 1 which is a single crystal film.

9. GeO directly or through other layers on a crystal substrate ２ 1. A laminated structure in which a crystal film containing as a main component is laminated, the crystal substrate and the crystal film being oriented in a (111) direction.

10. The laminated structure according to claim 7, wherein the crystal substrate and / or the crystal film is a semiconductor.

11. The GeO ２ 10. The crystal film according to claim 9, which has one or two of the following crystal structures: tetragonal or orthorhombic.

12. The GeO ２ The crystal film according to claim 9, which has a tetragonal crystal structure.

13. The GeO ２ The crystal film according to claim 9, which has an orthorhombic crystal structure.

14. The crystal film is 100 μm ２ The laminated structure according to claim 9, having an area of ​​at least 100 mm.

15. The laminated structure according to claim 9, wherein the crystal film has a thickness of 1 μm or more.

16. The laminated structure according to claim 9, wherein the surface roughness of said crystal film is 10 nm or less.

17. The laminated structure according to claim 9, wherein the crystal substrate contains silicon or a silicon-containing compound as a main component.

18. The laminated structure according to claim 9, wherein the crystal substrate is made of Si or SiC.

19. The laminated structure according to claim 9, wherein the crystalline film is a single crystalline film.

20. A laminate structure in which a crystal film is laminated directly or via another layer on a crystal substrate whose surface part or all of which contains silicon or a silicon-containing compound as a main component, wherein the surface part or all of which has a (111) orientation and the crystal film contains a metal oxide containing germanium as a main component.

21. The laminated structure according to claim 20, wherein the crystalline film has any one of a tetragonal, an orthorhombic, and a trigonal crystal structure.

22. A laminate structure in which a crystal film containing a Ge-containing metal oxide as a main component is laminated on a crystal substrate directly or via another layer, wherein the crystal substrate and / or the other layer have a thermal conductivity of 100 W / mK or more.

23. A laminate structure in which a crystal film is laminated directly on a crystal substrate or via another layer, the crystal substrate or the other layer containing as its main component a metal or metal compound containing a d-block element and / or a p-block element of the periodic table and having a cubic crystal structure, and the crystal film containing as its main component a metal oxide containing Ge.

24. A laminate structure in which a crystal film containing GeO2 as a main component is laminated on a crystal substrate directly or via another layer, characterized in that the crystal substrate or the other layer contains a carbon-containing compound as a main component.

25. A laminate structure in which a crystal film is laminated directly or via another layer on a crystal substrate whose surface part or all of which contains silicon or a silicon-containing compound as a main component, wherein the surface part or all of which is (100) oriented and the crystal film contains a metal oxide containing germanium as a main component.

26. A laminated structure in which a crystal film is laminated directly on a crystal substrate or via another layer, characterized in that the crystal substrate or the other layer has a (100) orientation and the crystal film has a (111) orientation.

27. The layered structure of claim 26, wherein said crystalline film contains germanium.

28. The laminated structure according to claim 26, wherein the crystal film contains a compound containing germanium as a main component.

29. The laminated structure according to claim 26, wherein the crystalline film has one or two types of tetragonal or orthorhombic crystal structures.

30. A semiconductor device including a crystal film or a laminated structure, wherein the crystal film is the crystal film described in claim 1, and the laminated structure is the laminated structure described in claim 9, 20, 22, 23, 24, 25 or 26.

31. The semiconductor device according to claim 30, which is a power device.

32. The semiconductor device according to claim 30, which is a Schottky barrier diode (SBD), a junction barrier Schottky diode (JBS), a high electron mobility transistor (HEMT), a metal oxide semiconductor field effect transistor (MOSFET), a junction field effect transistor (JFET), an insulated gate bipolar transistor (IGBT) or a light emitting diode (LED).

33. An electronic device including a semiconductor device, characterized in that the semiconductor device is the semiconductor device according to claim 30.

34. A system including an electronic device, the electronic device being the electronic device of claim 33.

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