KR102226901B1 - Electrically conductive thin films and production methods thereof - Google Patents

Abstract

Obtaining a raw material for a thin film containing Hf ₃ Te _2;
Obtaining a crystalline material having a surface for forming a thin film comprising Hf ₃ Te _2; And
There is provided a method of manufacturing a thin film _{containing Hf 3} Te ₂ including the step of forming a thin film containing _{Hf 3} Te ₂ on the surface of the crystalline material from the raw material, wherein the crystalline material is composed of It has a crystal structure including a regular arrangement of atoms, and an arbitrary polygon or polyhedron that repeats regularly in the regular arrangement can be drawn, and the length of one side of the polygon or polyhedron relative to the lattice constant of _{Hf 3} Te ₂ The ratio of the minimum difference between and the lattice constant is 5% or less.

Description

Conductive thin film and its manufacturing method {ELECTRICALLY CONDUCTIVE THIN FILMS AND PRODUCTION METHODS THEREOF}

It relates to a conductive thin film and a method of manufacturing the same.

Electronic devices such as flat panel displays such as LCD or LED, touch screen panels, solar cells, and transparent transistors include a conductive thin film or a transparent conductive thin film. The conductive thin film material may be required to have a high light transmittance of, for example, 80% or more, and a low resistivity of, for example, 100 μ Ω*cm or less in the visible light region. Examples of oxide materials currently used include indium tin oxide (ITO), tin oxide (SnO ₂ ), and zinc oxide (ZnO). ITO, which is widely used as a transparent electrode material, has poor flexibility and a price increase is inevitable due to limited reserves of indium, and development of a material to replace it is urgently required. Tin oxide and zinc oxide are also not highly conductive and have poor flexibility.

After the excellent conductive properties of graphene are known, studies on thin films containing a layered structure material having a weak interlayer bonding force are actively conducted. Graphene is attracting attention as a highly flexible transparent conductive film material to replace indium tin oxide (ITO), which has poor mechanical properties. However, graphene has a high absorption coefficient and has poor transmittance, and a thin film having a thickness of 4 or more monoatomic layers is difficult to use as a transparent conductive film. Transition metal dichalcogenide (TMD), which is a kind of layered structure compound, has an optical gap and can exhibit satisfactory transmittance, but its conductivity is only at the level of a semiconductor, so it is not easy to apply it to a conductive film.

One embodiment relates to a method for manufacturing a flexible conductive thin film while having high conductivity and excellent light transmittance.

Another embodiment relates to a composite including the conductive thin film.

In one embodiment, the method of manufacturing a thin film including _{Hf 3} Te _2,

Obtaining a raw material for a thin film containing Hf ₃ Te _2;

Obtaining a crystalline material having a surface for forming a thin film comprising Hf ₃ Te _2; And

Forming a thin film comprising _{Hf 3} Te ₂ on the surface of the crystalline material from the raw material,

The crystalline material has a crystal structure including a regular arrangement of constituent atoms, and any polygonal or polyhedron that is regularly repeated in the regular arrangement may be drawn,

The ratio of the minimum difference between the length of one side of the polygon or polyhedron and the lattice constant to the lattice constant of Hf ₃ Te _{2 is 5% or less.}

The raw material may be a hafnium or a mixture of a hafnium compound and a tellurium or tellurium compound, and in the mixture, a ratio between hafnium (Hf) and tellurium (Te) may be in the range of 3: 1.5 to 2.5.

The raw material may be a sintered body including a single phase _{of Hf 3} Te _2.

The crystalline material may include graphene, CaNdAlO ₄ , MgO, _{SrTiO 3} , or LaAlO ₃ .

The crystalline material may be disposed as a buffer layer on the substrate. The substrate may include an inorganic material, an organic material, an organic-inorganic hybrid material, or a combination thereof.

The step of forming the thin film may be performed by physical vapor deposition (PVD), chemical vapor deposition (CVD), pulsed laser deposition (PLD), or a combination thereof.

Forming the thin film may include heating the crystalline material to a temperature higher than 700 degrees Celsius.

Forming a thin film, surface Hf ₂ Te ₃ in the (001) plane growth, Hf ₂ Te ₃ (110) may include a growth, or a combination thereof.

The ratio may be 1% or less.

_{The Hf 3} Te ₂ thin film formed on the surface of the crystalline material is an amorphous thin film without a crystal peak identified by an X-ray diffraction spectrum, and the method, the amorphous thin film formed on the surface of the crystalline material is 700 degrees Celsius. It may further include a step of heat-treating at a temperature in the range of 1200 degrees Celsius.

A composite comprising a _{layer of a crystalline material and a Hf 3} Te ₂ thin film in contact with a surface of the layer of the crystalline material,

The crystalline material has a crystal structure including a regular arrangement of constituent atoms, and any polygonal or polyhedron that is regularly repeated in the regular arrangement may be drawn,

The ratio of the minimum difference between the length of one side of the polygon or polyhedron and the lattice constant to the lattice constant of _{Hf 3} Te _{2 may be 5% or less.}

The Hf ₃ Te ₂ thin film may have an electrical conductivity of 2000 S/cm or more.

The crystalline material may include graphene, CaNdAlO ₄ , MgO, _{SrTiO 3} or LaAlO ₃ .

The Hf ₃ Te ₂ thin film may exhibit a peak corresponding to the (110) plane of the _{Hf 3} Te ₂ crystal in the X-ray diffraction spectrum.

According to an embodiment, a high-density free electron is confined in a two-dimensional layer, so that a Hf ₃ Te ₂ thin film having excellent transparency while having a high conductivity comparable to that of a metal, and a composite including the same can be formed. The obtained Hf ₃ Te ₂ thin film has a layered crystal structure and is capable of interlayer sliding due to a weak interlayer bonding force, thus exhibiting remarkably improved flexibility compared to a conventional transparent electrode material.

Figure 1 is Hf₃Te₂ It schematically shows the layered crystal structure of.
2 is Hf formed according to an embodiment₃Te₂ It shows a cross section of a structure including a thin film.
3 is, in one embodiment, Hf on graphene₃Te₂ It schematically shows the growth of the (001) plane of the thin film. In FIG. 3, a regular hexagon (indicated by a red solid line) that repeats regularly within a regular arrangement of carbon atoms constituting graphene may be drawn. The length of one side of the regular hexagon and Hf₃Te₂The lattice constants of are indicated respectively.
4 is, in one embodiment, Hf on graphene₃Te₂ It schematically shows the growth of the (110) plane of the thin film.
Figure 5 is CaNdAlO₄ The crystal unit cell of is schematically represented with the lattice constant.
6 is CaNdAlO₄ The front view and Hf of the crystal unit cell of₃Te₂The front view of the crystal unit cell of is shown together.
7 is Hf formed according to another embodiment₃Te₂ It shows a cross section of a structure including a thin film.
8 is Hf in Example 1₃Te₂ It shows the X-ray diffraction spectrum of the thin film.
9 is Hf in Example 2₃Te₂ It shows the X-ray diffraction spectrum of the thin film.
10 is Hf in Comparative Example 1₃Te₂ It shows the X-ray diffraction spectrum of the thin film.
11 is Hf in Example 3₃Te₂ The X-ray diffraction spectrum of the thin film is CaNdAlO₄ Is shown together with the diffraction spectrum of

Advantages and features of the present invention, and a method of achieving them will become apparent with reference to implementation examples described below in detail together with the accompanying drawings. However, the present invention is not limited to the embodiments disclosed below, but will be implemented in a variety of different forms, only the present embodiments make the disclosure of the present invention complete, and common knowledge in the technical field to which the present invention pertains. It is provided to completely inform the scope of the invention to the possessor, and the invention is only defined by the scope of the claims. Thus, in some implementations, well-known techniques have not been described in detail in order to avoid obscuring interpretation of the present invention. Unless otherwise defined, all terms (including technical and scientific terms) used in the present specification may be used as meanings that can be commonly understood by those of ordinary skill in the art to which the present invention belongs. In addition, terms defined in a commonly used dictionary are not interpreted ideally or excessively unless explicitly defined specifically. When a part of the specification "includes" a certain component, it means that other components may be further included rather than excluding other components unless specifically stated to the contrary.

In addition, the singular form includes the plural form unless specifically stated in the text.

In the drawings, the thickness is enlarged and shown in order to clearly express various layers and regions. Like reference numerals are used for similar parts throughout the specification.

In the present specification, when a part such as a layer, film, region, plate, etc. is said to be "on" another part, this includes not only the case where the other part is "directly above", but also the case where there is another part in the middle. Conversely, when one part is "directly above" another part, it means that there is no other part in the middle.

In one embodiment, the method of manufacturing a thin film containing _{Hf 3} Te _2,

Obtaining a raw material for a thin film containing Hf ₃ Te _2;

Obtaining a crystalline material having a surface for forming a thin film comprising Hf ₃ Te _2; And

_{Forming a thin film containing Hf 3} Te ₂ on the surface of the crystalline material from the raw material, wherein the crystalline material is a value obtained by multiplying its lattice constant or lattice constant by an arbitrary integer and Hf ₃ Te _It is selected so that the mismatch between the lattice constants of 2 is 5% or less. In theory, all materials except amorphous may have a crystal structure having an inherent lattice constant. Among these crystalline materials, a material with a minimum difference in lattice constant from _{Hf 3} Te _{2 may be selected as the aforementioned crystalline material.} The lattice constant may be the distance between atoms (e.g., in the case of graphene, the distance between CC atoms forming a cube, 1.4226 angstroms), or the distance between the midpoint between atoms and other midpoints (e.g., in the case of graphene, It may be 3.694 angstroms, which is the distance between the CC center points). The mismatch may be 2% or less, or 1% or less. In other words, the crystalline material has a crystal structure including a regular arrangement of constituent atoms, and an arbitrary polygon or polyhedron that is regularly repeated in the regular arrangement may be drawn, and the length of one side of the polygon or polyhedron ( When the minimum value of the difference (La) between the lattice constant (a) of L) and Hf ₃ Te ₂ is min(La), the value of min(La)/a is 0.05 or less. In one embodiment, the value of min(La)/a may be 0.02 or less, or 0.01 or less.

When the crystal structure of the crystalline material is two-dimensional, an arbitrary polygon that repeats within the crystal structure may be drawn. For example, referring to FIG. 3, in the case of graphene, a repeating regular hexagon may be drawn in a crystal structure in a manner in which the midpoints between C and C atoms are connected, and in this case, the length of one side is 3.694 angstroms. When the crystal structure of the crystalline material is three-dimensional, an arbitrary polyhedron that repeats in the crystal structure can be drawn, and the polyhedron is determined according to the lattice system of the crystalline material. For example, referring to FIGS. 5 and 6, since _{the lattice constant (a) of the unit lattice of CaNdAlO 4} is 3.688 angstroms, the polyhedron may have one side of a length of 3.688 angstroms. On the other hand, as shown in Fig. 1, _{the lattice constants of Hf 3} Te ₂ are a = 3.6837 angstroms, b = 3.6837 angstroms, and c = 17.9010 angstroms.

Therefore, when the crystalline material is graphene, the _{minimum value of the difference between the length of one side of the polygon and the lattice constant of Hf 3} Te ₂ is 0.0103 (= 3.694-3.6837), which is the lattice constant of _{Hf 3} Te _{2 (a} = 3.6837 angstroms), which is 0.0028 (i.e. 0.28%). The crystalline material is CaNdAlO ₄ In the case of, the minimum value of the difference between the length of one side of the polyhedron and _{the lattice constant of Hf 3} Te ₂ is 0.0043 (= 3.688-3.6837), and this is the ratio to the lattice constant of _{Hf 3} Te _{2 (a = 3.6837 angstroms)} Converted to 0.0012 (i.e. 0.12%)

Hf ₃ Te ₂ is a highly conductive layered material with a layered crystal structure. As shown in FIG. 1, Hf ₃ Te ₂ has a crystal structure in which unit structure layers are repeated, and each unit structure layer has upper and lower layers surrounded by Te elements, and the inside is filled with Hf metal elements. Hf ₃ Te ₂ has a ^{crystal structure in which electrons of a high density (10 21} /cm ³ or more) are confined within a regular two-dimensional crystal structure, and thus can exhibit high electrical conductivity (1000 S/cm or more). At the same time, _{the unit structure layers of Hf 3} Te ₂ are relatively weakly bonded by van der Waals force, so that interlayer sliding is possible. Therefore, _{it is considered that the thin film including Hf 3} Te ₂ can exhibit remarkably superior flexibility compared to the conventional conductive thin film. In addition, Hf ₃ Te ₂ can be controlled only in the direction of the plane desired to grow in (physical or chemical) vapor deposition or pulsed laser deposition, providing a thin film with a very thin thickness (less than 50 nm) and high crystallinity. You can expect to be there.

In this regard, surprisingly, the present inventors have _{confirmed that the crystallinity and conductivity of the Hf 3} Te ₂ -containing thin film formed by vapor deposition significantly differs depending on the type of material providing the deposition surface. _{In one embodiment, when the Hf 3} Te ₂ thin film is deposited on the surface of the crystalline material that satisfies the above-described conditions, a thin film having high crystallinity and high conductivity can be manufactured. Although not intending to be bound by a specific theory, when _{the crystal lattice mismatch between the crystal plane of the material providing the deposition surface and the crystal lattice mismatch of Hf 3} Te ₂ is small, in the deposition process, the growth of the _{Hf 3} Te _{2 thin film is} Along the crystal structure plane of, (for example, thermodynamically stable) planes in a specific direction (for example, (110) plane and (001) plane) can be guided, and as a result, the crystallinity of the prepared thin film is remarkably It is believed that the improved electrical conductivity of the prepared thin film is also significantly increased. _{According to the above-described method, a thin film including Hf 3} Te ₂ having a thickness of 100 nm or less, such as 50 nm or less, can be formed, and the prepared thin film has excellent crystallinity and conductivity, and is 60% or more, for example, 70% or more of light. Transmittance can be implemented.

The _{raw material for the thin film containing Hf 3} Te ₂ is not particularly limited and may be appropriately selected according to the method of forming the thin film. In one embodiment, the raw material may be a mixture of hafnium or hafnium compound and tellurium or tellurium compound, and the ratio between hafnium (Hf) and tellurium (Te) in the mixture is in the range of 3: 1.5 to 2.5. I can. The mixture may be a powdery mixture. In one embodiment, the raw material may be a sintered body including a single phase of _{Hf 3} Te _2. The sintered body may be manufactured by densifying a (eg, polycrystalline) bulk material (eg, pellet) by sintering or the like. The bulk material may _{be prepared by a quartz ampoule method comprising the step of putting a powdery mixture having a composition of Hf 3} Te _{2 in a} quartz tube or an ampoule made of metal, sealing with a vacuum, and heat treatment to perform a solid phase reaction or melting. In addition, it can also be produced by an arc melting method or a solid-phase reaction method. The arc melting method may include a step of melting and then solidifying the raw material elements by performing arc discharge in an atmosphere of an inert gas (eg, nitrogen, argon, etc.) into a chamber. The solid-phase reaction method may include mixing and pelletizing raw material powders to heat-treat the obtained pellets, or heat-treating the raw material powder mixture and then pelletizing and sintering.

Densification of the obtained bulk material can be performed by a hot press method, a spark plasma sintering method, a hot posing method, or the like. The hot pressing method is a method of applying a powder compound to a mold having a predetermined shape, and molding at a high temperature, for example, 300°C to 800°C, and a high pressure, for example, 30 Pa to 300 MPa. The spark plasma sintering method involves sintering a material in a short time by passing a high voltage current to the powder compound under a high pressure condition, for example, a current of 50A to 500A at a pressure of about 30 MPa to about 300 Mpa. In one embodiment, in the spark plasma sintering method, a sintered body including a single phase of _{Hf 3} Te ₂ may be obtained by sintering the prepared bulk material at a temperature range of 1100°C to 1300°C for 30 minutes or more. The hot posing method may include extruding and sintering the powder compound at a high temperature of, for example, 300°C to 700°C.

Crystalline materials having a surface for the formation of thin films comprising Hf ₃ Te _{2 can be prepared by known methods or are commercially available.} As detailed above, the crystalline material is _{selected such that a mismatch between its lattice constant or a multiple thereof and the lattice constant of Hf 3} Te ₂ is 5% or less, for example, 1% or less. The crystalline material may include a crystal structure made of a two-dimensional repeating unit. The crystalline material may include graphene. The crystalline material may include a crystal structure made of a three-dimensional repeating unit. The crystalline material may include _{CaNdAlO 4, MgO, SrTiO 3,} LaAlO 3, or a combination thereof.

The crystalline material may be disposed on a substrate as a buffer layer. The substrate may be any substrate used in the deposition process. For example, the substrate is a silicon oxide (SiO ₂ ), aluminum oxide (Al ₂ O ₃ ), a glass substrate, or an inorganic material including a combination thereof, an organic material including various polymers such as polyimide, or a combination thereof. It may include, but is not limited thereto. Referring to FIG. 2, a thin film of the aforementioned crystalline material such _{as graphene or CaNdAlO 4 is formed as a buffer layer on a substrate, and Hf 3} Te ₂ A thin film can be formed. In another embodiment, the crystalline material itself may be used as a deposition substrate. _{Referring to Figure 7, Hf 3} Te ₂ on the substrate of the crystalline material A thin film can be deposited.

The step of forming the thin film may be performed by physical vapor deposition (PVD), chemical vapor deposition (CVD), pulsed laser deposition (PLD), or a combination thereof. Physical vapor deposition may include various sputtering methods such as DC sputtering, RF sputtering, bias sputtering, etc., thermal evaporation deposition, or electron beam evaporation deposition. Physical vapor deposition (PVD), chemical vapor deposition (CVD), and pulsed laser deposition (PLD) can be performed in known or commercially available equipment, and conditions other than those mentioned as limiting in this specification ( For example, the pressure in the chamber, the atmosphere of the vapor deposition, the temperature, the output, the voltage, etc.) can be appropriately selected from known conditions, and are not particularly limited. In one embodiment, thin film formation may be performed according to pulsed laser deposition. In this case, the pressure in the chamber may be in the range of 100 mTorr or less, for example, 25 mTorr or less, and the laser power is in the range of 50 mJ to 500 mJ (eg, 250 mJ), and the frequency of the laser is 0.1 Hz to 50 Hz. The range of, the number of shots may be in the range of 100 to 10000, but is not limited thereto. The inside of the chamber may be in a vacuum or inert gas atmosphere.

In one embodiment, when depositing a thin film by the method described above, it may include raising the crystalline material to a temperature higher than 700 degrees Celsius, for example, 780 degrees Celsius or higher, 790 degrees Celsius or higher, or 800 degrees Celsius or higher. I can. In this temperature range, a thin film having higher crystallinity can be prepared.

When forming a thin film in the above-described manner, _{the growth of the Hf 3} Te ₂ thin film may include growth in the (001) plane direction, growth in the (110) plane direction, or a combination thereof.

_{In one embodiment, the Hf 3} Te ₂ thin film formed on the surface of the crystalline material may be an amorphous thin film without crystal peaks identified by an X-ray diffraction spectrum. For example, when a thin film formed by deposition, if the temperature of the surface of the crystalline material to less than 700 seeds, Hf ₃ Te ₂ deposited Hf ₃ Te ₂ thin film in the diffraction X-ray as mentioned above It may not exhibit a characteristic peak of the crystal. When the thus obtained amorphous thin film is heat-treated at a temperature of 700 degrees Celsius or higher, for example, in the range of 700 degrees Celsius to 1200 degrees Celsius on the surface of the crystalline material, crystals showing characteristic peaks of _{Hf 3} Te _{2 crystals in the X-ray diffraction spectrum} A thin film can be obtained.

The prepared Hf ₃ Te ₂ thin film may exhibit high crystallinity, improved conductivity, and excellent flexibility, and thus may replace a conductive thin film including Ag nanowires such as electrodes including transparent conductive oxides such as ITO and ZnO.

Another embodiment is a composite comprising a _{layer of crystalline material and a Hf 3} Te ₂ thin film in contact with the surface of the layer of crystalline material,

The crystalline material has a crystal structure including a regular arrangement of constituent atoms, and any polygonal or polyhedron that is regularly repeated in the regular arrangement may be drawn,

The ratio of the minimum difference between the length of one side of the polygon or polyhedron and the lattice constant to the lattice constant of _{Hf 3} Te _{2 may be 5% or less.}

In the composite according to an embodiment, details of the thin film including the _{crystalline material and Hf 3} Te _{2 are as described above.}

The Hf ₃ Te ₂ thin film may have a high electrical conductivity of 2000 S/cm or more, for example, 5000 S/cm or more, 6000 S/cm or more, or 7000 S/cm or more. The crystalline material may be graphene, CaNdAlO ₄ , MgO, _{SrTiO 3} or LaAlO ₃ . The thickness of the Hf ₃ Te ₂ thin film is not particularly limited and may be appropriately selected. In order to secure the transparency of the thin _{film, the thickness of the Hf 3} Te ₂ thin film may be 20 nm or less, for example, 50 nm or less. The Hf ₃ Te ₂ thin film may exhibit a peak corresponding to the (110) plane of the _{Hf 3} Te ₂ crystal in the X-ray diffraction spectrum.

The above-described Hf ₃ Te ₂ thin film forming method and _{the composite including the Hf 3} Te ₂ thin film thus formed can be used as an electrode material in various electronic devices. For example, _{the composite including the aforementioned Hf 3} Te ₂ thin film is a flat panel display (eg, LCD, LED, OLED), a touch screen panel, a solar cell, an e-window, a heat mirror, a transparent transistor, or a flexible It can be used as an electrode material in various electronic devices such as a display (flexible display).

Hereinafter, specific embodiments of the present invention are presented. However, the examples described below are only for illustrating or explaining the present invention in detail, and the present invention is not limited thereto.

[ Example ]

Reference Example 1 : Hf ₃ Te ₂ sintered body manufacturing

In a glove box, Hf metal (or Hf compound) powder and Te metal (or Te compound) powder are mixed so that Hf:Te = 3:2 (molar ratio) to prepare a raw material mixture. The prepared raw material mixture is put into a quartz glass tube and the inside of the tube is sealed under vacuum conditions. The quartz glass tube was placed in a box furnace and the temperature was raised to 1000°C after 1 day, maintained at this temperature for 5 days, and then gradually cooled to room temperature (solid phase method performed). In order to improve the uniformity of the sample, the sample subjected to the primary heat treatment may be subdivided and subjected to the secondary heat treatment under the same conditions.

Spark plasma sintering (SPS) at a pressure of 70 MPa and a temperature of 1100 degrees Celsius using Spark Plasma Sintering equipment (manufacturer: Fuji Electronic Industrial Co., Ltd. model name: Dr. Sinter) do. X-ray diffraction spectral analysis was performed on the prepared sintered body to confirm that it is _{a single-phase Hf 3} Te _{2 sintered body.} The produced sintered body has a high density corresponding to 98% of the theoretical density.

Example 1 : Hf ₃ Te ₂ thin film deposition on graphene (pulse laser deposition)

A 0.3 nm-thick graphene layer was formed on the surface of the Si/SiO _{2 substrate (manufactured by LG Siltron) by the CVD method.} The prepared Si/SiO ₂ substrate including a graphene layer is mounted on a pulsed laser deposition apparatus (manufacturer: PVD Products, model name: PLD 5000). _{The Hf 3} Te ₂ sintered body prepared in Reference Example 1 was used as a target, and the substrate temperature was set to 400 degrees, 500 degrees, 600 degrees, 700 degrees, 800 degrees, and 850 degrees Celsius under the following conditions. Type laser deposition to form a Hf ₃ Te ₂ thin film (thickness: about 35 nm):

The pressure in the chamber, laser power, laser frequency, and number of shots are 20mTorr, 250mJ, 1Hz, and 2000shots, respectively. Ar atmosphere inside the chamber.

Each prepared Hf ₃ Te ₂ thin film was subjected to X-ray diffraction analysis using a D8 Advance (manufactured by Bruker Corporation) instrument, and the results are shown in FIG. 8. From the results of FIG. 8, when pulse-type laser deposition is performed with the temperature of the substrate including the graphene layer at a temperature higher than 700 degrees Celsius (for example, 800 degrees Celsius and 850 degrees Celsius), a thin film showing a _{Hf 3} Te _{2 crystal peak} Confirm that you can get When the deposition surface temperature is increased from 800°C to 850°C, the (103) plane peak increases, and the (006) plane and (110) plane peaks are still observed.

For the prepared Hf ₃ Te ₂ thin film (850 degrees Celsius), measure the electrical conductivity of the specimen using a multimeter (Keithley 2420 source meter) at room temperature according to the 4-probe DC method. That is, after applying a current to the sample and measuring the corresponding voltage drop, the resistance is measured from the IV graph, and then the specific resistance is calculated by considering the sample size.

Example 2 : Hf ₃ Te _{2 thin film deposition on CaNdAlO 4} (pulse laser deposition)

A CaNdAlO ₄ substrate (manufacturer: Surface Net) was mounted on a pulsed laser deposition apparatus (manufacturer: PVD Products, model name: PLD 5000). _{Using the Hf 3} Te ₂ sintered body prepared in Reference Example 1 as a target, and performing pulsed laser deposition under the same conditions as in Example 1 with a substrate temperature of 800 degrees Celsius, a Hf ₃ Te ₂ thin film (thickness: about 20 nm):

Each prepared Hf ₃ Te ₂ thin film was subjected to X-ray diffraction analysis using a D8 Advance (manufactured by Bruker Corporation) instrument, and the results are shown in FIG. 9. From the results of FIG. 9, it was confirmed that a _{Hf 3} Te ₂ thin film having excellent crystallinity _{was formed on CaNdAlO 4.}

For the prepared Hf ₃ Te ₂ thin film, measure the electrical conductivity of the specimen using a multimeter (Keithley 2420 source meter) at room temperature according to the 4-probe DC method.

Comparative Examples 1 to 2 : Hf ₃ Te _{2 thin film deposition on Al 2} O ₃ and SiO ₂ (pulse laser deposition)

As a substrate for deposition, the graphene instead of using Al ₂ O _3, and SiO _2, respectively, and perform the PLD to and is the same method as in Example 1 except that the deposition when the substrate temperature to 850 seeds and Hf ₃ Form a Te ₂ thin film. Fig. 10 shows the X-ray diffraction spectrum of the formed thin film. From the results of FIG. 10, it is confirmed that the Hf ₃ Te ₂ thin film _{deposited on Al 2} O ₃ and SiO ₂ does not exhibit a peak inherent in the _{Hf 3} Te _{2 crystal.} The minimum value of the lattice constant difference between Al ₂ O ₃ and Hf ₃ Te ₂ is 1.0743 (= 4.758-3.6837 angstroms), and thus the ratio (degree of mismatch) to the lattice constant between _{Hf 3} Te _{2 is 29%.} .

_{The electrical conductivity of the Hf 3} Te ₂ thin film deposited on Al ₂ O ₃ was measured in the same manner as in Example 1. The results are summarized in Table 1.

division Evaporation substrate Evaporation temperature Lattice constant
Degree of mismatch conductivity Comparative Example 1 Al2O3 850 degrees 29% 300 S/cm Example 1 Graphene 850 degrees 0.28% 2000 S/cm Example 2 CaNdAlO4 850 degrees 0.12% 15000 S/cm

Example 3 :

_{In Example 1, the Hf 3} Te ₂ thin film deposited with a substrate temperature of 700 degrees Celsius was heat-treated at 800 degrees Celsius in a vacuum atmosphere. The obtained Hf ₃ Te ₂ thin film was subjected to X-ray diffraction spectroscopy, and the results are shown in FIG. 11. As can be seen from FIG. 11, it _{is confirmed that the Hf 3} Te ₂ thin film heat-treated on the graphene substrate exhibits a crystalline peak inherent _{in Hf 3} Te _2.

Although the preferred embodiments of the present invention have been described in detail above, the scope of the present invention is not limited thereto, and various modifications and improvements by those skilled in the art using the basic concept of the present invention defined in the following claims are also present. It is within the scope of the invention's rights.

Claims (16)

As a method for producing a thin film containing Hf ₃ Te _2,
Obtaining a raw material for a thin film containing Hf ₃ Te _2;
Obtaining a crystalline material having a surface for forming a thin film comprising Hf ₃ Te _2; And
Forming a thin film comprising _{Hf 3} Te ₂ on the surface of the crystalline material from the raw material,
The crystalline material has a crystal structure including a regular arrangement of constituent atoms, and any polygonal or polyhedron that is regularly repeated in the regular arrangement may be drawn,
The ratio of the minimum difference between the length of one side of the polygon or polyhedron and the lattice constant with respect to the lattice constant of Hf ₃ Te _{2 is 5% or less,}
The crystalline material comprises CaNdAlO ₄ . The method of claim 1,
The raw material is a hafnium or a mixture of a hafnium compound and a tellurium or tellurium compound, and the ratio between hafnium and tellurium in the mixture is in the range of 3:1.5 to 3:2.5. The method of claim 1,
The raw material is a method of a sintered body containing a single phase _{of Hf 3} Te _2. delete The method of claim 1,
The method in which the crystalline material is disposed as a buffer layer on a substrate. The method of claim 5,
The substrate is a method comprising an inorganic material, an organic material, an organic-inorganic hybrid material, or a combination thereof. The method of claim 1,
The step of forming the thin film is performed by physical vapor deposition (PVD), chemical vapor deposition (CVD), pulsed laser deposition (PLD), or a combination thereof. The method of claim 1,
The step of forming the thin film includes raising the temperature of the surface of the crystalline material to a temperature higher than 700 degrees Celsius. The method of claim 1,
Forming a thin film, comprising a (110) surface growth, or a combination of Hf ₃ Te ₂ (001) surface growth, Hf ₃ Te _2. The method of claim 1,
The method in which the ratio is 1% or less. The method of claim 1,
_{The Hf 3} Te ₂ thin film formed on the surface of the crystalline material is an amorphous thin film without crystal peaks identified by an X-ray diffraction spectrum, and the amorphous thin film formed on the surface of the crystalline material is 700 to 1200 degrees Celsius. The method further comprising the step of heat-treating at a temperature in the range of the seed. A composite comprising a _{layer of crystalline material and a Hf 3} Te ₂ thin film in contact with the surface of the layer of crystalline material,
The crystalline material has a crystal structure including a regular arrangement of constituent atoms, and any polygonal or polyhedron that is regularly repeated in the regular arrangement may be drawn,
The ratio of the minimum difference between the length of one side of the polygon or polyhedron and the lattice constant with respect to the lattice constant of _{Hf 3} Te _{2 is 5% or less,}
The crystalline material is a composite containing _{CaNdAlO 4.} The method of claim 12,
The Hf ₃ Te ₂ thin film is a composite having an electrical conductivity of 2000 S/cm or more. delete The method of claim 12,
The Hf ₃ Te ₂ thin film is a composite exhibiting a peak corresponding to the (110) plane of the _{Hf 3} Te ₂ crystal in the X-ray diffraction spectrum. The method of claim 12,
The Hf ₃ Te ₂ thin film is a composite having a thickness of less than 100 nm.

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