KR101881304B1 - Method for preparing thin film of two-dimensional transition metal dichalcogenide having high uniformity - Google Patents

Abstract

The present invention relates to a method for producing a high-uniform two-dimensional transition metal decalcogenide thin film, and more particularly, to a method for producing a highly uniform two-dimensional transition metal decalcinate thin film at a low temperature of 500 ° C or lower.

Description

BACKGROUND OF THE INVENTION 1. Field of the Invention [0001] The present invention relates to a method for preparing a high-uniform two-dimensional transition metal decalcogenide thin film having a two-dimensional transition metal dichalcogenide having high uniformity,

The present invention relates to a method for producing a highly uniform two-dimensional transition metal decalcinate thin film.

A two-dimensional (2D) material means a material having a layered structure. Typical examples of such a two-dimensional material include graphene, transition metal dichalcogenide, and the like. Also, a two-dimensional material having a thickness that changes physical / chemical properties in comparison with a bulk is referred to as a two-dimensional thin film.

Various studies have shown that graphene is a promising candidate material that can replace materials used in conventional electronic devices. However, graphene is well suited for transistors and optical devices due to a lack of bandgap (0 eV for pure graphene), despite the excellent properties of high electron mobility, elasticity, thermal conductivity, and flexibility I do not. On the other hand, molybdenum disulfide (MoS ₂ ), which is a laminated structure material agglomerated by covalent bonds and interlayer van der Waals forces of transition metal dicalcogenides, for example, one molybdenum atom located between two sulfur atoms, (2D) material due to its adjustable bandgap (from an indirect band gap of 1.2 eV (bulk) to a direct band gap of 1.8 eV (single layer)] and ambient stability.

The fabrication of the MoS ₂ monolayer was first attempted by a micromechanical exfoliation method similar to the approach used for the fabrication of graphene, and its applicability as a channel material for a field effect transistor (FET) . Since the study of improving the electrical properties of MoS ₂ using a dielectric screening method has been published, it has become possible to use a variety of materials such as micro-mechanical and chemical exfoliation, lithiation, thermolysis, and two-step thermal evaporation Various synthetic processes have been studied. Subsequently, sulphurization of the pre-deposited Mo has been developed, and it has been found that the sulfuration is a somewhat suitable method for the synthesis of large area MoS ₂ . However, MoS ₂ produced by the sulfidation of the pre-deposited Mo exhibits non-uniformity and low field effect mobility as compared to the exfoliated sample, and the MoS ₂ is sometimes incomplete with pre-deposited Mo and sulfur Due to the bonding, it is grown vertically on the substrate. Chemical vapor deposition (CVD) is a well-known method for large-area MoS ₂ growth. Lee et al. [Lee, Y.-H. et al. Synthesis of largearea MoS ₂ atomic layers with chemical vapor deposition. Adv. Mater. 24, 2320-2325 (2012) molybdenum trioxide (MoO _3), a very effective method of a CVD method using a molybdenum oxysulfide (MoO3-x) and sulfur powder Reduction from growth of MoS ₂ atomic layer on a dielectric substrate that . Using similar methods, studies on large area high quality MoS ₂ with larger crystal size or layer number control were conducted.

Typical characteristics for determining the quality of a two-dimensional thin film include grain size and uniformity. In the past, a two-dimensional thin film having a large crystal size was recognized as being of high quality. Kang, X. Xie, L. Huang, Y. Han, P. Y. Huang, K. F. Mak, C.-J. According to Kim, D. Muller and J. Park, High-mobility three-atom-thick semiconducting films with wafer-scale homogeneity, Nature, 520, 656-660, 2015, a highly uniform two- , It showed 3 ~ 4 times higher physical properties than the two - dimensional thin film produced by the peeling method known to have the best quality. Therefore, the synthesis of two-dimensional thin films with high uniformity is emerging as a key technology for determining the quality of two-dimensional thin films.

In order to synthesize a MOS ₂ having a uniform thickness, a MOS ₂ fabrication method known so far requires a high temperature condition of at least 550 ° C and a suitable synthesis for MOS ₂ having a uniform thickness at a low temperature of 500 ° C or lower The method has not been reported yet. The high temperatures in the substrate due to (usually dielectric) the movement of the MoS ₂ molecules on the surface is also very high in, without forming the bilayer (double layer, the second layer) of MoS ₂ on the substrate, monolayer (single layer of MoS _2, Only the first layer) can be synthesized uniformly over a large area (8 inches or more). However, due to the low temperature conditions, the movement of the MoS ₂ molecules at the surface of the substrate is also very low, and the crystal size and prevent the growth above a certain size, before covering the entire large-area substrate with a monolayer of MoS ₂ in the MoS ₂ bilayer generation occurs, which tends to induce the formation of a three-dimensional (3D) structure of MoS _{2 on} the substrate.

More specifically, the mobility of molecules on the substrate surface is expressed by the diffusion length due to Einstein's relation (Equation 1). In this case, if the synthesis temperature is too low, the diffusion length on the surface becomes short, and the molecules evaporate on the surface before bonding. In addition, the van der Waals force does not allow the molecules adsorbed on the monolayer to move to the monolayer lateral position, and provides a nucleation site capable of forming a bilayer, so that in the Volmer-Weber growth mode, The thin film is synthesized in the Stranski-Krastanow growth mode (see FIG. 1). Therefore, synthesis of monolayer thin films with high uniformity is generally performed at high temperatures. In general, in a high-temperature synthesis condition, a thin film is synthesized in a Frank-Van der Merve growth mode due to a high migration at the substrate surface, and the entire substrate can be coated with a monolayer, The thin film is synthesized in the Bolmer-Weber growth mode or the Strandsky-Kristanov growth mode due to the low molecular movement on the substrate surface, and the entire substrate can not be coated with the monolayer.

[Formula 1]

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lambda: diffusion length,

T: temperature,

λ _{0 is the} pre-exponential factor,

E _a : adsorption energy,

E _d : diffusion barrier,

K _B : Boltzmann constant

Therefore, it is necessary to develop a manufacturing method capable of growing a two-dimensional thin film having a high uniformity on a large-area substrate of 8 inches or more and a two-dimensional transition metal decalcogenic thin film having a high uniformity even at a low temperature of 500 ° C. or less to be.

The present invention provides a method for producing a highly uniform two-dimensional transition metal decalcogenide thin film, and more specifically, a method for producing a highly uniform two-dimensional transition metal decalcinate thin film at a low temperature of 500 ° C or lower.

The present invention provides, as one means for solving the above problems,

Reducing the surface energy of the substrate through surface treatment of the substrate within the deposition chamber; And

Providing a chalcogen-containing precursor, a transition metal-containing precursor and a precursor decomposition promoting catalyst in the deposition chamber to deposit a two-dimensional transition metal dicalcium phosphate monolayer on the substrate;

The present invention provides a method for producing a two-dimensional transition metal decalcogenide thin film.

In the deposition step, an inhibitor may be additionally provided to prevent generation of a two-dimensional transition metal dicalcium salt bilayer.

The adsorption energy of the inhibitor is higher at the lateral positions of the substrate and the transition metal discoccinimide monolayer than the basal plane of the transition metal discoccinimide monolayer,

The adsorption energy of chalcogen is higher at the base of the substrate and the transition metal decalcogenide fault than at the lateral position of the transition metal decalcogenide fault.

The precursor decomposition promoting catalyst promotes the decomposition of ligands bound to the chalcogen atoms from the chalcogen atoms in the chalcogen-containing precursor and / or decomposes the ligands bound to the transition metal atoms from the transition metal atoms in the transition metal- . ≪ / RTI >

The surface treatment of the substrate is performed by a wet treatment method selected from the group consisting of piranha solution treatment, sulfuric acid (H ₂ SO ₄ ) solution treatment, hydrochloric acid (HCl) solution treatment and alkali metal hydroxide solution treatment; Or an O ₂ plasma treatment and a heat treatment using water vapor.

Wherein the substrate is a SiO _2, Al2O _3, HfO _2, LiAlO _3, MgO, Si, Ge, GaN, AlN, GaP, InP, GaAs, SiC, glass, quartz, sapphire, graphite, graphene, plastic, polymer, boron nitride (h-BN), and combinations thereof.

Wherein the substrate is a SiO _2, Al2O _3, HfO _2, LiAlO _3, MgO, and is selected from the group consisting of surface treatment of the substrate is piranha (piranha) solution process, the process of sulfuric acid (H ₂ SO ₄₎ solution , A hydrochloric acid (HCl) solution treatment, and an alkali metal hydroxide solution treatment; Or an O ₂ plasma treatment and a heat treatment using water vapor.

The chalcogen-containing precursor may be an S-containing organic compound or an S-containing inorganic compound.

The transition metal-containing precursor may be selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Nb, Ta, Mo, W, Tc, Re, Ru, Os, Rh, , A transition metal selected from the group consisting of Cd, In, Tl, Sn, Pb, Sb, Bi, Zr, Pd, Hf and combinations thereof.

The ratio of partial pressure of the chalcogen-containing precursor / partial pressure of the transition metal-containing precursor may be 1/2 or more.

The ratio of the partial pressure of the chalcogen-containing precursor / the partial pressure of the transition metal-containing precursor may be 2 or more.

The deposition step may be performed at a temperature of 500 DEG C or lower.

The deposition step may be performed by a chemical vapor deposition (CVD) method.

In the deposition step, the ratio of the partial pressure of the chalcogen-containing precursor / the transition metal-containing precursor is increased to decrease the cluster size of the transition metal decalcogenide produced by the gas phase reaction, Dimensional growth of dicalcogenide can be induced.

In the deposition step, the amount of the chalcogen-containing precursor and the transition metal-containing precursor supplied into the deposition chamber is controlled by adjusting the amount of the carrier gas or by controlling the temperature of the chalcogen-containing precursor and the transition metal-containing precursor , The ratio of the chalcogen-containing precursor partial pressure / transition metal-containing precursor partial pressure can be adjusted.

The present invention also provides, as another means for solving the above problems,

(1) reducing the surface energy of the substrate through surface treatment of the substrate in the deposition chamber;

(2) supplying a chalcogen-containing precursor and a transition metal-containing precursor into the deposition chamber at a temperature of 500 DEG C or less and a pressure of 0.001 Torr to 760 Torr to form crystals of two-dimensional transition metal dicalcium co- ;

(3) supplying a chalcogen-containing precursor and a transition metal-containing precursor into the deposition chamber to increase the crystal size of the two-dimensional transition metal dicalcium co-crystal on the substrate under an increased pressure than the pressure of step (2) ; And

(4) supplying a chalcogen-containing precursor and a transition metal-containing precursor into the deposition chamber under an increased pressure than the pressure of step (3) to form a two-dimensional transition metal decalcopyrite monolayer on the substrate;

The present invention provides a method for producing a two-dimensional transition metal decalcogenide thin film.

In the above steps (2) to (4), a precursor decomposition promoting catalyst may be additionally supplied into the deposition chamber.

Further, in the above steps (2) to (4), an inhibitor for preventing generation of a two-dimensional transition metal dicalcium phosphate bilayer may be additionally provided.

According to one embodiment of the present invention, by controlling the cluster (or crystal) size and the nucleation position of the two-dimensional transition metal dicalcium cyanide, a two-dimensional transition metal dicalcopyrite Since the low temperature growth can be performed in the temperature range described above, the two-dimensional transition metal decalcinate thin film having a large area and high uniformity can be directly grown on the flexible substrate or the substrate.

The two-dimensional transition metal decalcogenide thin film according to one embodiment of the present invention can be used as an element, and the thin film can be utilized as a next generation flexible device and a wearable device by being a polycrystalline monolayer and a two-dimensional structure have.

1 is a schematic diagram showing a growth mode of a thin film on a substrate surface. In general, at high temperature conditions (for example, at a temperature condition of 550 DEG C or higher), a thin film is synthesized in the Frank-Van der Merve growth mode due to high molecular movement on the substrate surface, Can be coated with a single layer (ML, monolayer) thin film, but under low temperature conditions (for example, at a temperature condition of 500 DEG C or less), the Volmer-Weber growth mode ) Or a Stranski-Krastanow growth mode, so that the entire substrate can not be covered with the single-layer thin film.
FIG. 2 is a graph showing the results of a scanning electron microscope (SEM) showing a result of nucleation at the surface of a substrate according to the concentration of a potassium hydroxide solution when a SiO ₂ substrate is treated with a potassium hydroxide (KOH) It is an electron microscope image.
FIG. 3 is a scanning electron microscope image showing the result of synthesis of a two-dimensional transition metal decalcogenide thin film according to whether a precursor decomposition accelerating catalyst is used or not in the deposition step according to an embodiment of the present invention. FIG.
FIG. 4 is a scanning electron microscope image (a) to (c) and a Raman spectrum ((d) and (e)) showing the result of synthesis of a two-dimensional transition metal decalcinate thin film according to the temperature in the deposition chamber.
FIG. 5 is a schematic diagram showing the result of synthesis of a two-dimensional transition metal decalcogenide thin film according to whether or not an inhibitor is used to prevent generation of a two-dimensional transition metal dicalcogenide bilayer in the deposition step according to an embodiment of the present invention. to be.
FIG. 6 is a graph showing the results of the synthesis of a two-dimensional transition metal decalcogenide thin film according to the presence or absence of an inhibitor to prevent generation of a two-dimensional transition metal dicalcogenide bilayer in the deposition step according to an embodiment of the present invention. It is an electron microscope image.
FIG. 7 is a scanning electron microscope image showing the result of synthesis of a two-dimensional transition metal decalcinate thin film according to a pressure in a deposition chamber according to an embodiment of the present invention. FIG.
FIG. 8 illustrates an embodiment of the present invention. FIG. 8 illustrates a method of fabricating a semiconductor device according to an embodiment of the present invention. Referring to FIG. 8, (B) growing crystals into large-sized nucleated crystals, and (c) forming a high-uniformity two-dimensional transition metal decalcopyrite monolayer thin film on the substrate through a pressure change. Is a schematic view showing a method for producing a metal decalcinate thin film.

Hereinafter, embodiments of the present invention will be described in detail with reference to the accompanying drawings so that those skilled in the art can easily carry out the present invention. It should be understood, however, that the present invention may be embodied in many different forms and should not be construed as limited to the embodiments set forth herein. In the drawings, the same reference numbers are used throughout the specification to refer to the same or like parts.

Throughout this specification, when a part is referred to as being "connected" to another part, it is not limited to a case where it is "directly connected" but also includes the case where it is "electrically connected" do.

Throughout this specification, when a member is " on " another member, it includes not only when the member is in contact with the other member, but also when there is another member between the two members.

Throughout this specification, when an element is referred to as " including " an element, it is understood that the element may include other elements as well, without departing from the other elements unless specifically stated otherwise.

The terms " about ", " substantially ", etc. used to the extent that they are used throughout the specification are intended to be taken to mean the approximation of the manufacturing and material tolerances inherent in the stated sense, Accurate or absolute numbers are used to help prevent unauthorized exploitation by unauthorized intruders of the referenced disclosure. The word " step (or step) " or " step " used to the extent that it is used throughout the specification does not mean " step for.

Throughout this specification, the term " combination (s) thereof " included in the expression of the machine form means a mixture or combination of one or more elements selected from the group consisting of the constituents described in the expression of the form of a marker, Quot; means at least one selected from the group consisting of the above-mentioned elements.

Throughout this specification, the description of "A and / or B" means "A, or B, or A and B".

Throughout this specification, the transition metal dicalcium cyanide particles produced by the gas phase reaction of the chalcogen atoms and the transition metal atoms generated by the decomposition reaction of the chalcogen-containing precursor and the transition metal-containing precursor supplied in the deposition chamber are referred to as & "

Throughout the specification, it is to be understood that throughout the specification, the chalcogen-containing precursor and the transition metal-containing precursor fed into the deposition chamber are deposited on the surface of the substrate and then either produced by surface reactions of chalcogen atoms and transition metal atoms, After the generated clusters are diffused to the surface of the substrate, the transition metal dicalcium cyanide particles produced by the surface reaction are referred to as "crystals ".

Hereinafter, embodiments and examples of the present invention will be described in detail with reference to the accompanying drawings. However, the present invention is not limited to these embodiments and examples and drawings.

The present invention provides a method of manufacturing a semiconductor device, comprising: reducing surface energy of a substrate through surface treatment of the substrate in a deposition chamber; And supplying a chalcogen-containing precursor, a transition metal-containing precursor and a precursor decomposition-promoting catalyst into the deposition chamber to deposit a two-dimensional transition metal decalcopyrite monolayer on the substrate. The present invention relates to a method for producing a thin film of transition metal dicocosinide.

The method for fabricating the two-dimensional transition metal decalcogenide thin film according to the present invention may include reducing the surface energy of the substrate through surface treatment of the substrate in the deposition chamber. Reducing the surface energy of the substrate through surface treatment of the substrate is to enrich the nucleation site on the substrate surface.

The number of nucleation sites on the surface of the substrate is a very important factor in forming highly uniform thin films, particularly single-layered films. By controlling the surface energy of the substrate, the number of nucleation sites on the surface of the substrate can be controlled and the number of nucleation sites affects the crystal size and uniformity of the two-dimensional transition metal decahydrate.

Specifically, when nucleation sites are rarely present on the surface of the substrate, crystals of transition metal dicalcium cyanide are formed to a large size. However, the entire substrate can not be covered with the two-dimensional transition metal decalcogenide thin film, . On the other hand, if the nucleation site is abundant on the surface of the substrate, the crystals of the transition metal decalcogenide are formed in a small size, but the whole substrate can be covered with the two-dimensional transition metal decalcogenide thin film, . The number of nucleation sites on the surface of such a substrate can be controlled through surface treatment of the substrate.

In an embodiment of the present invention, when an oxide-based insulator selected from the group consisting of SiO ₂ , Al ₂ O ₃ , HfO ₂ , LiAlO ₃ , MgO, and combinations thereof is used as the substrate, Existing hydroxyl groups (-OH bonds) are provided to the nucleation site, and the number of hydroxyl groups (-OH bonds) can be controlled through surface treatment of various substrates.

For example, piranha solution treatment, sulfuric acid (H ₂ SO ₄ ) solution treatment, hydrochloric acid (HCl (H ₂ SO ₄ )) solution treatment, and the like are effective for increasing the hydroxyl group (-OH bond) ) A wet treatment method selected from the group consisting of a solution treatment and an alkali metal hydroxide solution treatment; Or an O ₂ plasma treatment and a heat treatment using steam. The surface treatment of the substrate can be carried out by a dry treatment method selected from the group consisting of an O ₂ plasma treatment and a steam treatment. Examples of the alkali metal hydroxide solution include a potassium hydroxide solution and a sodium hydroxide solution. The wet treatment method is not limited to the above, and any solution can be used as long as it can reduce the surface energy of the oxide-based insulator substrate. In the preparation of the wet treatment solution, the content of the solute in the solution is 0.0001 wt% or more, preferably 0.0001 wt% to the weight% at the maximum solubility (since the solubility of each solution varies depending on the solute, The upper limit value may be changed), but not limited thereto, any ratio can be used. The dry treatment method is not limited to the above, and any gas or molecule can be used as long as it can reduce the surface energy of the oxide-based insulator substrate.

In order to reduce the hydroxyl group (-OH bond) on the surface of the substrate and rarely provide the nucleus growth position, a method capable of removing the hydroxyl group (-OH bond), for example, a vacuum heat treatment, an annealing treatment, High vacuum annealing, and combinations thereof. However, the present invention is not limited thereto. Any method can be used as long as it can remove the hydroxyl group (-OH bond). For example, when a high vacuum annealing process is selected as the surface treatment method of an oxide-based insulating substrate, by decomposing a dangling bond that provides a reactive surface position on the substrate by the high vacuum annealing, So that the size of the transition metal dicalcium cyanide crystal can be increased, but the uniformity of the two-dimensional transition metal decalcogenide thin film can be lowered.

In the case of a crystal substrate and a metal substrate, a position where surface defects exist can be provided as a nucleation growth position, and surface energy control by surface treatment of the substrate can be performed. Lt; RTI ID = 0.0 > nucleation < / RTI > Even in this case, the surface energy of the substrate can be reduced to enrich the nucleation growth position.

In the method for producing a two-dimensional transition metal disalcogenic thin film of the present invention, the surface energy of the substrate is reduced through surface treatment of the substrate, thereby enriching the nucleus growth position, thereby reducing the crystal size of the transition metal decalcogenide, The uniformity of the two-dimensional transition metal decalcinate thin film can be improved.

FIG. 2 is a graph illustrating the relationship between the concentration of a potassium hydroxide solution and the concentration of potassium hydroxide in the surface of a substrate in the step of reducing the surface energy of a substrate according to one embodiment of the present invention, when the SiO ₂ substrate is treated with a potassium hydroxide (KOH) ≪ / RTI > is a scanning electron microscope image showing the result.

FIG. 2 (a) is a graph showing the results of nucleation of a chalcogen-containing precursor and a transition metal-containing precursor in a deposition chamber without performing a surface treatment of the SiO ₂ substrate by using a scanning electron microscope And FIG. 2 (b) shows the result of the surface treatment of the SiO ₂ substrate with a 1 wt% potassium hydroxide solution, and then a chalcogen-containing precursor and a transition metal-containing precursor are fed into the deposition chamber, 2C is a scanning electron microscope image showing the result of nucleation. After the SiO ₂ substrate is surface-treated with a 10 wt% potassium hydroxide solution, a chalcogen-containing precursor and a transition metal-containing precursor Is an image of a scanning electron microscope showing the result of nucleation on the surface of a substrate by supplying a precursor.

As a result of comparison between FIG. 2 (a) and FIG. 2 (c), when the surface treatment of the substrate was not performed, the surface energy of the substrate was not reduced, nucleation sites were rarely present, 2 (a)). When the surface treatment of the substrate was performed using a potassium hydroxide solution, the surface energy of the substrate was reduced, and the nucleus growth was abundant, And 2 (c)). Particularly, the higher the concentration of the potassium hydroxide solution, the more abundant the nucleation site and the more nucleation.

In one embodiment of the present invention, the substrate is made of SiO ₂ , Al ₂ O ₃ , HfO ₂ , LiAlO ₃ , MgO, Si, Ge, GaN, AlN, GaP, InP, GaAs, SiC, glass, quartz, sapphire, A pin, a plastic, a polymer, boron nitride (h-BN), and combinations thereof, but is not limited thereto. As the substrate, a material which is inexpensive in terms of cost and advantageous for a large area may be preferable, and it is preferable that the number of nucleation positions can be controlled by adjusting the surface energy.

A method for preparing a two-dimensional transition metal decalcogenide thin film according to the present invention includes the steps of supplying a chalcogen-containing precursor, a transition metal-containing precursor and a precursor decomposition promoting catalyst into a deposition chamber, Lt; / RTI >

In one embodiment of the present invention, the chalcogen-containing precursor is selected from the group consisting of H ₂ S, CS ₂ , SO ₂ , S ₂ , H ₂ Se, H ₂ Te, R ₁ SR ₂ (NH ₄ ) ₂ S, C ₆ H ₈ OS (wherein R ₁ and R ₂ are each independently an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, or an alkynyl group having 2 to 6 carbon atoms) , S (C ₆ H ₄ NH ₂ ) ₂ , Na ₂ SH ₂ O, and combinations thereof, preferably H ₂ S, CS ₂ , SO ₂ , S ₂ , R ₁ SR ₂ (NH ₄ ) ₂ S, C ₆ H ₈ OS (wherein R ₁ and R ₂ are each independently an alkyl group having 1 to 6 carbon atoms, an alkenyl group having 2 to 6 carbon atoms, or an alkynyl group having 2 to 6 carbon atoms) , S-containing organic compounds or S-containing inorganic compounds selected from the group consisting of S (C ₆ H ₄ NH ₂ ) ₂ , Na ₂ SH ₂ O, and combinations thereof.

In one embodiment of the present invention, the transition metal-containing precursor is selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Nb, Ta, Mo, W, Tc, Re, A transition metal selected from the group consisting of Ir, Pt, Ag, Au, Cd, In, Tl, Sn, Pb, Sb, Bi, Zr, Te, Pd, Hf and combinations thereof may be used. It does not. For example, the transition metal-containing precursor may comprise one selected from the group consisting of Mo (CO) ₆ , Mo (Cl) ₅ , MoO (Cl) ₄ , MoO ₃ , But may not be limited thereto.

In one embodiment of the present invention, in the depositing step, for example, in a chemical vapor deposition step, a gas phase reaction, which is a homogeneous reaction, and a gas phase reaction, which is a heterogeneous reaction, The reaction occurs simultaneously. In the gas phase reaction, the gaseous reactants react with each other to form clusters of transition metal decanoides, and these clusters are transferred to the substrate surface to cause a surface reaction. Also, in the substrate surface reaction, the gaseous reactants can react with each other to form crystals of the transition metal decanoic acid.

For example, when a chalcogen-containing precursor and a transition metal-containing precursor are fed into the deposition chamber, a precursor decomposition reaction of the chalcogen-containing precursor and the transition metal-containing precursor takes place and the intermediate product of the decomposition of the precursor, The atoms and the transition metal atoms form clusters of transition metal decalcogenides through the gas phase reaction, and these clusters can be transferred to the substrate surface to cause surface reactions. Also on the substrate surface, chalcogen-containing precursors and transition metal-containing precursors, or intermediates resulting from their decomposition, can cause non-uniform reactions of the chalcogen atoms and transition metal atoms to form crystals of the transition metal decalcinate.

The chalcogen-containing precursor and the transition metal-containing precursor each have a specific precursor decomposition temperature, and the decomposition characteristics of these precursors can be an important factor in determining the synthesis temperature of the two-dimensional transition metal decalcinate thin film. If the synthesis of the two-dimensional transition metal decalcinate thin film is performed at a temperature lower than the decomposition temperature of the precursors, the synthesis rate may be lowered due to an incomplete reaction.

In one embodiment of the present invention, a precursor decomposition accelerating catalyst may be fed into the deposition chamber with a chalcogen-containing precursor and a transition metal-containing precursor. The precursor decomposition promoting catalyst promotes the decomposition of ligands bound to the chalcogen atoms from the chalcogen atoms in the chalcogen-containing precursor and / or decomposes the ligands bound to the transition metal atoms from the transition metal atoms in the transition metal- . ≪ / RTI > The precursor decomposition accelerating catalyst promotes the decomposition of these precursors and can be remarkably advantageous in terms of commercialization by improving the synthesis rate of the two-dimensional transition metal decalcinate thin film even under low temperature conditions (for example, at a temperature of 500 ° C or less).

For example, when molybdenum hexacarbonyl (Mo (CO) ₆ ) is used as the transition metal-containing precursor, the complete decomposition temperature of molybdenum hexacarbonyl is 250 ° C. However, when hydrogen is used as a precursor decomposition accelerating catalyst, The rate of synthesis of the two-dimensional transition metal decalcogenide thin film at 250 ° C may be increased several times as compared with the case of not using hydrogen, or even at a temperature lower than 250 ° C, the two-dimensional transition metal decalcinate thin film Can be realized in the same manner.

In one embodiment of the present invention, the precursor decomposition accelerating catalyst is not limited to a gaseous material such as hydrogen, and may catalyze the decomposition of a ligand bound to a chalcogen atom from a chalcogen atom in the chalcogen-containing precursor and / Can be used without limitation as long as it is capable of promoting the decomposition of a ligand bound to a transition metal atom from a transition metal atom in the - containing precursor.

FIG. 3 is a scanning electron microscope image showing the result of synthesis of a two-dimensional transition metal decalcinate thin film according to whether a precursor decomposition accelerating catalyst is used or not in the deposition step according to an embodiment of the present invention.

3 (a) shows the result of synthesis of a two-dimensional transition metal decalcogenide thin film when H ₂ is supplied as a precursor decomposition accelerating catalyst together with a chalcogen-containing precursor and a transition metal-containing precursor in a deposition chamber in a deposition step , Wherein the chalcogen-containing precursor and the transition metal-containing precursor are supplied in a deposition chamber without supplying a precursor decomposition accelerating catalyst into the deposition chamber, and Fig. 3 (b) is a scanning electron microscopic image showing a two- Scanning electron microscope image showing the synthesis result of the decalcogenid thin film.

3 (a) and comparing the results of FIG. 3 (b), when the synthesis of the precursor decomposition facilitating catalyst two-dimensional transition metal radical Koji arsenide thin film without there as, but takes a synthesis time of 9 hours, the precursor decomposition facilitating catalyst H ₂ , The total synthesis time of the two-dimensional transition metal decalcogenide thin film was 2 hours, and it was confirmed that the synthesis rate was increased 4.5 times by using the precursor decomposition accelerating catalyst.

As an embodiment of the present invention, in the deposition step, an inhibitor for preventing generation of a two-dimensional transition metal dicalciumbionide bilayer may be additionally provided.

Under low temperature conditions (for example temperatures below 500 ° C), the formation of a transition metal dicocosanide bilayer is easy, and this bilayer is the biggest barrier to the synthesis of a uniform two-dimensional transition metal decalcogenide monolayer film Which is a limit of low-temperature synthesis. Since the production of the double layer provides an active site, the probability of incorporation of impurities is increased, which may result in degradation of the quality of the two-dimensional transition metal decalcinate thin film.

4 is a scanning electron microscope image (a) to (c) and a Raman spectrum (d) and (e) showing the result of synthesis of a two-dimensional transition metal decalcogenide thin film according to the temperature in the deposition chamber .

As shown in Figs. 4 (a) to 4 (c), the chalcogen-containing precursor and the transition metal-containing precursor were introduced into the deposition chamber 1 at a temperature of 350 캜, 300 캜 and 250 캜, respectively, (MoS ₂ ) nuclei were formed on the substrate, the number of nucleation was small while the crystal size was increased when the temperature was 350 ° C. (see FIG. 4 (a)) (See FIG. 4 (b)) and the temperature is 250 ° C. (see FIG. 4 (c)), the number of nuclei increases as the temperature decreases, Can be confirmed.

As shown in FIGS. 4 (d) and 4 (e), it was confirmed that the formation of the double layer of transition metal dicalcium phosphate can be varied depending on the temperature in the deposition chamber through Raman spectroscopy. In general, the method used to distinguish monolayer and bilayer of transition metal dicaloginide is to calculate the distance between two peaks shown in Figure 4 (d). Li, Q. Zhang, CCR Yap, BK Tay, THT Edwin, A. Oliver, and D. Baillargeat, From Bulk to Monolayer MoS2: Evolution of Raman Scattering, Adv. Funct. Mater., 22, 1385-1390, 2012]. As shown in FIG. 4 (e), when the temperature in the deposition chamber is 350 ° C (FIG. 4 (a)), the value of A _1g -E ¹ _2g is about 19 and is confirmed as a monolayer of a two-dimensional transition metal decalcinate (Fig. 4 (c)), the diffusion distance is shortened and the value of A _1g -E ¹ _2g is increased to about 22, so that a double layer of two-dimensional transition metal decalcogenide can be generated .

In the present invention, in order to prevent the formation of a bilayer that deteriorates the quality of the two-dimensional transition metal decalcogenide thin film, the inhibitor is introduced into the deposition chamber together with a chalcogen-containing precursor, a transition metal-containing precursor and a precursor decomposition accelerating catalyst Or the chalcogen-containing precursor, the transition metal-containing precursor and the precursor decomposition accelerating catalyst may be first fed into the deposition chamber and the inhibitor may be fed into the deposition chamber after a certain period of time.

FIG. 5 is a schematic view showing the result of synthesis of a two-dimensional transition metal decalcinate thin film according to whether or not an inhibitor is used to prevent the formation of a two-dimensional transition metal decalcogenide double layer in the deposition step of an embodiment of the present invention .

As shown in Fig. 5 (a), when a two-dimensional transition metal decalcinate thin film is synthesized at a low temperature condition (for example, at a temperature of 500 캜 or less) without using an inhibitor, A transition metal dicocosinide molecule adsorbed on the two-dimensional transition metal decalcogenide monolayer by the van der Waals force due to the low molecular mobility while the crystal size of the transition metal decalcogenide increases, Can not migrate to the side position of the crystal and provide a new nucleation site on the two-dimensional transition metal dicalcopyrite monolayer. Accordingly, a single layer and a double layer of the two-dimensional transition metal decalcogenide can be simultaneously synthesized, resulting in the formation of a non-uniform two-dimensional transition metal decalcinate thin film.

As shown in FIG. 5 (b), when a thin film of a two-dimensional transition metal decalcinate is synthesized at a low temperature (for example, at a temperature of 500 ° C. or lower) while using H ₂ O as an inhibitor, A two-dimensional transition metal decalcopyrite monolayer is formed, and a basal plane of the two-dimensional transition metal decalcogenide monolayer (here, the base of the two-dimensional transition metal decalcodonide monolayer is a two- H ₂ O molecules are physically adsorbed as inhibitors at the upper surface or lower surface of the monolayer, and the transition metal decalcogenide molecules can not be adsorbed on the basal plane of the two-dimensional transition metal dicalcium phosphate monolayer. Thus, the transition metal decalcogenide molecules can form chemical bonds only at the lateral positions of the two-dimensional transition metal decalcogenide monolayer, and as a result, two-dimensional transition metal dicocosin Only a metal dicalcopyrite single layer can be formed. Therefore, when the inhibitor is supplied together with a chalcogen-containing precursor, a transition metal-containing precursor, and a precursor decomposition accelerating catalyst in a deposition chamber, it is possible to produce a highly uniform two-dimensional transition metal decalcopyrite monolayer film.

The material that can be used as an inhibitor for preventing the formation of the two-dimensional transition metal dicarcozone double layer is not particularly limited and may be any material capable of being physically adsorbed on the basal plane of the two-dimensional transition metal dicalcium phosphate monolayer. For example, H ₂ O can be used as the inhibitor.

In one embodiment of the present invention, preferably the inhibitor may meet the following requirements.

The adsorption energy of the inhibitor is higher at the lateral positions of the substrate and transition metal decalcogenide monolayer than at the basal plane of the transition metal decalcogenide monolayer and the adsorption energy of the chalcogen is higher than that of the transition metal decalcinoid monolayer Lt; / RTI > is higher at the base of the substrate and the transition metal < RTI ID = 0.0 > decalcogenide < / RTI >

FIG. 6 is a graph showing the results of the synthesis of a two-dimensional transition metal decalcogenide thin film according to the presence or absence of an inhibitor to prevent the formation of a two-dimensional transition metal dicalcogenide double layer in the deposition step according to an embodiment of the present invention. It is a microscopic image.

As shown in Fig. 6 (a), a low temperature condition in the deposition steps (for example, a temperature not higher than 500 ℃), with a supply of H ₂ O as inhibitors, chalcogen-containing precursor (e. G., S- Containing precursor (e.g., Mo-containing precursor) and a precursor decomposition promoting catalyst (e.g., H ₂ gas) into a deposition chamber to synthesize a two-dimensional transition metal decalcogenide thin film , A two-dimensional transition metal decalcogenide monolayer (gray portion) is mostly present, and a two-dimensional transition metal decalcogenide double layer (black portion) is rarely formed, thereby forming a uniform two-dimensional transition metal decalcinate thin film.

As shown in Fig. 6 (b), a low temperature condition in the deposition steps (for example, a temperature not higher than 500 ℃), without the supply of H ₂ O, as inhibitors chalcogen-containing precursor (e. G., S- containing When a two-dimensional transition metal decalcogenide thin film is synthesized by supplying only a transition metal-containing precursor (for example, a Mo-containing precursor) and a precursor decomposition promoting catalyst (for example, H ₂ gas) into a deposition chamber, , A monolayer (gray portion) and a plurality of double layers (black portion) of the two-dimensional transition metal decalcogenide are simultaneously formed to form an uneven two-dimensional transition metal decalcinate thin film.

In one embodiment of the present invention, in the deposition step, for example, in the chemical vapor deposition step, a gas phase reaction, which is a uniform reaction, and a reaction on a substrate surface which is a heterogeneous reaction occur simultaneously, React with each other to form clusters of transition metal dicalcium cyanide, and these clusters are transferred to the substrate surface to cause a surface reaction. Also, in the substrate surface reaction, the gaseous reactants can react with each other to form crystals of the transition metal decanoic acid. The cluster is formed in a larger size as the partial pressure ratio (P _CP / P _MP ) of the chalcogen-containing precursor (hereinafter referred to as "CP") to the transition metal-containing precursor (hereinafter referred to as "MP" In this case, nucleation occurs on the surface of the substrate and the gaseous materials stick to the side and grow in the form of an island. (Up to a certain size, it is called a nucleus. When the size grows, it is called an island. , Where clusters generated from the gaseous material are also transferred to the substrate surface by diffusion. At this time, when the substrate surface temperature is a high-temperature condition (for example, a temperature of 550 ° C or more), the crystal can grow into a two-dimensional structure by the surface diffusion effect, Or less), the surface diffusion effect does not actively occur because of insufficient energy. Therefore, by controlling the partial pressure ratio (P _CP / P _MP ) of the chalcogen-containing precursor to the transition metal-containing precursor to be very high to reduce the cluster size generated by the gas phase reaction and reducing the surface energy of the substrate during the surface reaction, The structure of the two-dimensional transition metal decalcinate thin film deposited under the conditions can be controlled.

In one embodiment of the present invention, as the partial pressure ratio (P _CP / P _MP ) of the chalcogen-containing precursor to the transition metal-containing precursor increases, the deposited two-dimensional transition metal decalcogenide thin film has irregular three- Region to the mixed structure of the two-dimensional triangular region, but the present invention is not limited thereto. For example, the higher the partial pressure ratio (P _CP / P _MP ) of the chalcogen-containing precursor to the transition metal-containing precursor, the lower the surface energy of the resulting transition metal dicalcium cyanide crystal, The two-dimensional growth of the metal dicalcosinide thin film can be induced.

In one embodiment of the present invention, as the partial pressure ratio (P _CP / P _MP ) of the chalcogen-containing precursor to the transition metal-containing precursor is further increased, the two-dimensional transition metal dicalcogenide has a smaller crystal size And can be completely changed into a two-dimensional triangular area.

In one embodiment of the present invention, the ratio of the chalcogen-containing precursor partial pressure / transition metal-containing precursor partial pressure (P _CP / P _MP ) may be about 1/2 or more or about 2 or more, but is not limited thereto. Preferably, the ratio of the chalcogen-containing precursor partial pressure / transition metal-containing precursor partial pressure (P _CP / P _MP ) is from about 1/2 to about 600, from about 1/2 to about 500, from about 1/2 to about 400, From about 1/2 to about 300, from about 1/2 to about 200, from about 1/2 to about 100, from about 2 to about 600, from about 2 to about 500, from about 2 to about 400, from about 2 to about 300, from about 2 To about 200, or from about 2 to about 100, by weight of the composition.

In one embodiment of the present invention, in the step of depositing, the ratio of the chalcogen-containing precursor partial pressure / transition metal-containing precursor partial pressure (P _CP / P _MP ) to the transition metal dicaloginide The cluster size can be reduced and the surface energy of the substrate can be reduced to induce the two-dimensional growth of the transition metal dicalcium cyanide.

In one embodiment of the present invention, in the depositing step, the pressure in the deposition chamber is adjusted to adjust the amount of the chalcogen-containing precursor and the transition metal-containing precursor supplied into the deposition chamber, so that the chalcogen-containing precursor partial pressure / The ratio of the transition metal-containing precursor partial pressure (P _CP / P _MP ) can be controlled. For example, in the depositing step, the chalcogen-containing precursor and the transition metal-containing precursor, which are supplied into the deposition chamber by adjusting the pressure in the deposition chamber through the fine adjustment of the carrier gas flow rate, The ratio (P _CP / P _MP ) of the partial pressure of the chalcogen-containing precursor partial pressure / transition metal-containing precursor may be finely controlled by finely adjusting the amount of the precursor, but is not limited thereto.

As an embodiment of the present invention, as the ratio of the partial pressures of the chalcogen-containing precursor / transition metal-containing precursor ( _CPP / _PMP ) increases, the volatile byproducts desorb from the pseudo- Dimensional region can be grown and changed into a single layer by surface diffusion.

In one embodiment of the present invention, the depositing step may be performed at a low temperature of about 500 DEG C or lower, but may not be limited thereto. For example, the low temperature range may be about 500 ° C or less, about 400 ° C or less, about 350 ° C or less, or about 300 ° C or less, and preferably from about room temperature to about 500 ° C, From about 200 ° C to about 400 ° C, from about 200 ° C to about 400 ° C, from about 300 ° C to about 400 ° C, from about 100 ° C to about 350 ° C, or from about 200 ° C to about 350 ° C.

In an embodiment of the present invention, the depositing step may be performed by a chemical vapor deposition (CVD) method, for example, without limitation, But may not be limited thereto. For example, the chemical vapor deposition may be performed by a low pressure chemical vapor deposition (LPCVD) method, an atmospheric pressure chemical vapor deposition (APCVD) method, a metal organic chemical vapor deposition (MOCVD), plasma enhanced chemical vapor deposition (PECVD), inductively coupled plasma-chemical vapor deposition (ICP-CVD), atomic layer deposition, or plasma But is not limited to, atomic layer deposition.

In one embodiment of the present invention, the crystal size of the two-dimensional transition metal decalcogenide may be about 10 nm or more, but it is not limited thereto. For example, the crystal size of the two-dimensional transition metal dicalcium co-crystal may be greater than about 10 nm, greater than about 30 nm, greater than about 50 nm, greater than about 70 nm, or greater than about 100 nm, less than about 200 nm, About 130 nm or less, or about 100 nm or less, and specifically about 10 nm to about 200 nm, about 30 nm to about 200 nm, about 50 nm to about 200 nm, about 50 nm to about 100 nm, About 60 nm to about 90 nm, about 50 nm to about 80 nm, about 50 nm to about 70 nm, about 50 nm to about 60 nm, about 60 nm to about 100 nm, about 60 nm to about 90 nm, But is not limited to, from about 60 nm to about 70 nm, from about 70 nm to about 100 nm, from about 70 nm to about 90 nm, from about 70 nm to about 80 nm, or from about 80 nm to about 100 nm .

(1) reducing the surface energy of the substrate through surface treatment of the substrate in the deposition chamber; (2) supplying a chalcogen-containing precursor and a transition metal-containing precursor into the deposition chamber at a temperature of 500 DEG C or less and a pressure of 0.001 Torr to 760 Torr to form crystals of two-dimensional transition metal dicalcium co- ; (3) supplying a chalcogen-containing precursor and a transition metal-containing precursor into the deposition chamber to increase the crystal size of the two-dimensional transition metal dicalcium co-crystal on the substrate under an increased pressure than the pressure of step (2) ; And (4) providing a chalcogen-containing precursor and a transition metal-containing precursor in the deposition chamber under an increased pressure than the pressure in step (3) to form a two-dimensional transition metal decalcopyrite monolayer on the substrate To a process for producing a two-dimensional transition metal decalcinate thin film.

In the above steps (2) to (4), the precursor decomposition accelerating catalyst may be further supplied into the deposition chamber together with the chalcogen-containing precursor and the transition metal-containing precursor.

In addition, in the above steps (2) to (4), the inhibitor for preventing generation of the two-dimensional transition metal dicalcogenide bilayer may be used together with the chalcogen-containing precursor and the transition metal- May be further fed into the deposition chamber, along with a precursor, a transition metal-containing precursor and a precursor decomposition promoting catalyst. The inhibitor may be fed into the deposition chamber simultaneously with a chalcogen-containing precursor, a transition metal-containing precursor and a precursor decomposition accelerating catalyst, or the chalcogen-containing precursor, the transition metal-containing precursor and the precursor decomposition promoting catalyst may be introduced into the deposition chamber And the inhibitor may be supplied into the deposition chamber after a predetermined time.

Hereinafter, the description of the duplicated matters will be omitted, and the steps (2) to (4) may be a specific process of depositing the two-dimensional transition metal decalcopyrite monolayer.

Generally, as the number of nucleation sites on the surface of a substrate is smaller, a two-dimensional transition metal decalcogenide thin film having a large crystal size is synthesized, but the uniformity may be lowered in this case. On the other hand, as the number of nucleation sites on the surface of the substrate increases, a two-dimensional transition metal decalcogenide thin film having a small crystal size is synthesized, but the uniformity can be improved in this case.

As one embodiment of the present invention, it is possible to provide a method of manufacturing a thin film of a two-dimensional transition metal decalcogenide having a large crystal size and an improved uniformity at a low temperature.

First, nucleation can be induced for a certain period of time under a condition capable of forming a large number of nuclei on the surface of the substrate. To this end, it is possible to perform the step of reducing the surface energy of the substrate through the surface treatment of the substrate in the deposition chamber. Reducing the surface energy of the substrate through surface treatment of the substrate is to increase the number of nucleation sites on the substrate surface.

Thereafter, a chalcogen-containing precursor, a transition metal-containing precursor, an optional precursor decomposition promoting catalyst, and an optional inhibitor are supplied into the deposition chamber at a temperature of 500 DEG C or less and at a pressure of 0.001 Torr to 760 Torr, A step of generating crystals of the two-dimensional transition metal dicalcogenide can be performed. Thus, although a crystal size is small at the beginning of synthesis, a large number of nuclei can be grown on the surface of the substrate.

Thereafter, a chalcogen-containing precursor, a transition metal-containing precursor, an optional precursor decomposition accelerating catalyst and an optional inhibitor are supplied into the deposition chamber while the temperature of the crystal generating step remains the same while the pressure is increased The step of increasing the crystal size of the two-dimensional transition metal dicalcium cyanide on the substrate can be performed. The pressure condition increased from the crystal formation step is a synthesis condition in which a nucleus formed of a small-size crystal can grow to a large crystal size, and only a pressure higher than the pressure used in the crystal formation step is required. Specifically, It is not limited. The change of these pressure conditions can increase the small crystal size nuclei to large crystal sizes.

For example, when the pressure in the deposition chamber is set to 3 Torr in the crystal generation step, the pressure in the deposition chamber may be set to 9 Torr in the crystal size increasing step, but is not limited thereto.

7 is an image of a scanning electron microscope showing the result of synthesis of a two-dimensional transition metal decalcogenide thin film according to the pressure in a deposition chamber.

As shown in Fig. 7 (a), with the pressure in the deposition chamber set at 3 Torr, a chalcogen-containing precursor and a transition metal-containing precursor were fed into the deposition chamber to form a two-dimensional transition metal dicalcogenide (MoS ₂ ) nuclei are generated, the number of nuclei increases and the crystal size thereof decreases. On the other hand, with the pressure in the deposition chamber set at 9 Torr as shown in FIG. 7 (b) Containing precursor and a transition metal-containing precursor into the deposition chamber to form the nucleus of the two-dimensional transition metal decalcogenide (MoS ₂ ) on the substrate, the nucleation number is decreased and the crystal size is increased have.

Thereafter, a chalcogen-containing precursor, a transition metal-containing precursor, an optional precursor decomposition promoting catalyst, and an optional inhibitor are introduced into the deposition chamber while the temperature of the crystal size increasing step is kept the same while the pressure is increased And forming a two-dimensional transition metal dicalcium phosphate monolayer on the substrate. The pressure condition increased from the crystal size increasing step is a synthesis condition in which a nucleus grown with a large crystal size can be grown as a homogeneous two-dimensional transition metal decanoccinimide monolayer, and only a pressure higher than the pressure used in the crystal size increasing step , The upper limit of the increase of the pressure is not particularly limited. Through this pressure change, a two-dimensional transition metal decakosinide monolayer thin film with improved uniformity can be manufactured.

As an embodiment of the present invention, the manufacturing method according to the present invention can improve the uniformity of the high-quality, high-quality Dimensional transition metal decalcogenide thin film of the two-dimensional transition metal decalcogenide thin film of the present invention can be produced, and a device having excellent electrical performance can be manufactured by using the two-dimensional transition metal decalcogenide thin film thus prepared.

The two-dimensional transition metal decalcogenide thin film prepared above can be applied to all electronic circuits and electronic devices, but is not limited thereto. For example, it may be possible to manufacture a field effect transistor, an optical sensor, a light emitting device, a photodetector, a photomagnetic memory device, a photocatalyst, a flat panel display, a flexible device, .

In one embodiment of the present invention, the field effect transistor including the two-dimensional transition metal decalcogenide is excellent in electrical performance and exhibits a trend of a conventional n-type semiconductor.

[ Example ]

In the following examples, the present invention will be described in more detail with reference to examples of the present invention and comparative examples that do not comply with the present invention. However, the present invention is not limited thereto. But is not limited by the examples.

Example 1

Highly-doped (<0.005 OMEGA .cm) p-type Si having a 300 nm-thick SiO ₂ layer was used as the substrate. The substrate was pre-cleaned and placed on a silicon carbide (SiC) -coated susceptor in a load-lock chamber within a short time to prevent any contamination in the environment. The surface of the substrate was then treated with potassium hydroxide solution to reduce the surface energy of the substrate. H ₂ S as the chalcogen-containing precursor, Mo (CO) ₆ (= 99.9%, Sigma Aldrich, CAS number 13939-06-5) as the transition metal-containing precursor, H ₂ gas as the precursor decomposition accelerating catalyst, H ₂ O was supplied into the chamber as an inhibitor to prevent the formation of a transition metal dicarcogenide double layer, and a MoS ₂ thin film as a two-dimensional transition metal decalcogenide thin film was formed in a showerhead-type reactor by chemical vapor deposition (CVD) Were synthesized. The heating block in the CVD was preheated to 250 占 폚 before growth. The susceptor with the substrate was transferred to a reactor, and the substrate temperature was increased over 10 minutes in argon flow. The synthesis was carried out using only sublimed precursors of H ₂ S, Mo (CO) ₆ , H ₂ and H ₂ O at constant pressure (eg, 3.0 Torr) for synthesis time. After synthesis, the substrate was transferred to a load-lock chamber and cooled for 1 hour using an argon flow of 100 sccm. The post-synthesis treatment was not performed by any known methods (such as argon and H2S annealing at high temperature).

Comparative Example 1

MoS ₂ thin film as a two-dimensional transition metal decalcinate thin film was synthesized in the same manner as in Example 1, except that H ₂ gas as a precursor decomposition accelerating catalyst was not supplied into the chamber.

Comparative Example 2

A two-dimensional transition metal decalcogenide thin film of MoS ₂ was formed in the same manner as in Example 1, except that H ₂ O, which is an inhibitor for preventing generation of a two-dimensional transition metal decalcogenide double layer, was not supplied into the chamber. Were synthesized.

Example 2

Highly-doped (<0.005 OMEGA .cm) p-type Si having a 300 nm-thick SiO ₂ layer was used as the substrate. The substrate was pre-cleaned and placed on a silicon carbide (SiC) -coated susceptor in a load-lock chamber within a short time to prevent any contamination in the environment. The surface of the substrate was then treated with potassium hydroxide solution to reduce the surface energy of the substrate. H ₂ S as a chalcogen-containing precursor, Mo (CO) ₆ (= 99.9%, Sigma Aldrich, CAS number 13939-06-5) as a transition metal-containing precursor, H ₂ O is supplied into the chamber as an inhibitor to prevent the formation of H ₂ gas and a two-dimensional transition metal dicocosanide double layer as an accelerating catalyst to produce crystals of MoS ₂ on the substrate by chemical vapor deposition (CVD) . Also, H ₂ S, Mo (CO) ₆ , H ₂ and H ₂ O were fed into the chamber under constant pressure of 9.0 Torr for a period of time to increase the crystal size of MoS ₂ produced on the substrate. Then, H ₂ S, Mo (CO) ₆ , H ₂ and H ₂ O are fed into the chamber for a certain period of time under a constant pressure of more than 9 Torr (for example, 12 Torr) MoS ₂ thin film as a two-dimensional transition metal decalcogenide thin film was synthesized by forming a decalcoginide monolayer. The heating block in the CVD was preheated to 250 占 폚 before growth. The susceptor with the substrate was transferred to a reactor, and the substrate temperature was increased over 10 minutes in argon flow. After synthesis, the substrate was transferred to a load-lock chamber and cooled for 1 hour using an argon flow of 100 sccm. The post-synthesis treatment was not performed by any known methods (such as argon and H2S annealing at high temperature).

3 (a) shows a microscope image of the result of synthesis of the MoS ₂ thin film of Example 1 using H ₂ gas as a precursor decomposition accelerating catalyst in order to compare the effect of using the precursor decomposition accelerating catalyst, and H ₂ gas FIG. 3 (b) shows a microscope image of the result of the synthesis of the MoS ₂ thin film of Comparative Example 1 in which the film was not used.

3 (a) and 3 (b), when a two-dimensional transition metal decalcinate thin film was synthesized without a precursor decomposition accelerating catalyst, a total synthesis time of 9 hours was required (see FIG. 3 (b) , A total synthesis time of 2 hours is required for synthesizing a two-dimensional transition metal decalcinate thin film while using H ₂ as a precursor decomposition accelerating catalyst (see FIG. 3 (a)). By using a precursor decomposition accelerating catalyst, It can be confirmed that the synthesis rate of the two-dimensional transition metal dicocosinide thin film is improved by 4.5 times.

In order to compare the effect of using inhibitors to prevent the formation of a two-dimensional transition metal dicocosanide double layer, a microscope image of the result of synthesis of the MoS ₂ thin film of Example 1 using H ₂ O as the inhibitor is shown in FIG. 6 (a), and a microscope image of the result of synthesis of MoS ₂ thin film of Comparative Example 2 in which H ₂ O is not used is shown in FIG. 6 (b).

As a result of comparison between Fig. 6 (a) and Fig. 6 (b), H ₂ O as an inhibitor is supplied in a deposition step at a low temperature condition (for example, at a temperature of 500 ° C or lower) to form a two-dimensional transition metal decalcinate thin film When synthesized, a two-dimensional transition metal decalcinoid monolayer (gray portion) was mostly present, and a two-dimensional transition metal decalcogenide double layer (black portion) was rarely formed and a uniform two-dimensional transition metal decalcinate thin film was formed In the case of synthesizing a thin film of two-dimensional transition metal decalcogenide without supplying H ₂ O as an inhibitor in a deposition step of a low temperature condition (for example, a temperature of 500 ° C or lower) A large number of double layers (black portions) were formed simultaneously with a single layer (gray portion) of the dimensionally-transferred metal decalcogenide to form an uneven two-dimensional transition metal decalcogenide thin film (see FIG. 6 (b)).

As shown in FIG. 8, the MoS ₂ thin film was synthesized according to Example 2. As a result, it was possible to synthesize a highly uniform polycrystalline MoS ₂ thin film with improved uniformity.

While the present invention has been particularly shown and described with reference to exemplary embodiments thereof, it is to be understood that the invention is not limited to the disclosed exemplary embodiments, Of the right.

Claims (18)

Reducing the surface energy of the substrate through surface treatment of the substrate within the deposition chamber; And
Supplying a chalcogen-containing precursor, a transition metal-containing precursor and a precursor decomposition promoting catalyst into the deposition chamber to deposit a two-dimensional transition metal decalcopyrite monolayer on the substrate,
A method of making a two-dimensional transition metal decalcogenide thin film, wherein in said depositing step, an inhibitor is additionally provided to prevent formation of a two-dimensional transition metal dicalcogenide bilayer. delete The method according to claim 1,
The adsorption energy of the inhibitor is higher at the lateral positions of the substrate and transition metal decalcogenide fault than the basal plane of the transition metal decalcogenide fault,
Wherein the adsorption energy of the chalcogen is higher in the basal plane of the substrate and the transition metal decalcogenide monolayer than in the lateral position of the transition metal decalcogenide monolayer. The method according to claim 1,
The precursor decomposition accelerating catalyst promotes the decomposition of a ligand bound to a chalcogen atom from a chalcogen atom in a chalcogen-containing precursor or promotes the decomposition of a ligand bound to a transition metal atom from a transition metal atom in a transition metal- (Method for manufacturing a two - dimensional transition metal dicalcopyrite thin film). The method according to claim 1,
The surface treatment of the substrate is performed by a wet treatment method selected from the group consisting of piranha solution treatment, sulfuric acid (H ₂ SO ₄ ) solution treatment, hydrochloric acid (HCl) solution treatment and alkali metal hydroxide solution treatment; Or an O ₂ plasma treatment and a heat treatment using steam. 2. A method for producing a two-dimensional transition metal decalcogenide thin film according to claim 1, The method according to claim 1,
Substrates are SiO _2, Al2O _3, HfO _2, LiAlO _3, MgO, Si, Ge, GaN, AlN, GaP, InP, GaAs, SiC, glass, quartz, sapphire, graphite, graphene, plastic, polymer, boron nitride ( h-BN), and combinations thereof. &lt; RTI ID = 0.0 &gt; 11. &lt; / RTI &gt; The method according to claim 1,
The substrate is selected from the group consisting of _{SiO 2, Al 2 O 3,} HfO 2, LiAlO 3, MgO, and combinations thereof,
The surface treatment of the substrate is performed by a wet treatment method selected from the group consisting of piranha solution treatment, sulfuric acid (H ₂ SO ₄ ) solution treatment, hydrochloric acid (HCl) solution treatment and alkali metal hydroxide solution treatment; Or an O ₂ plasma treatment and a heat treatment using steam. 2. A method for producing a two-dimensional transition metal decalcogenide thin film according to claim 1, The method according to claim 1,
Wherein the chalcogen-containing precursor is an S-containing organic compound or an S-containing inorganic compound. The method according to claim 1,
The transition metal-containing precursor may be selected from the group consisting of Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, Nb, Ta, Mo, W, Tc, Re, Ru, Os, Rh, Wherein the transition metal comprises a transition metal selected from the group consisting of Cd, In, Tl, Sn, Pb, Sb, Bi, Zr, Pd, Hf and combinations thereof. The method according to claim 1,
Wherein the ratio of partial pressure of the chalcogen-containing precursor / partial pressure of the transition metal-containing precursor is 1/2 or more. 11. The method of claim 10,
Wherein the ratio of partial pressure of the chalcogen-containing precursor / partial pressure of the transition metal-containing precursor is 2 or more. The method according to claim 1,
Wherein the deposition step is performed at a temperature of &lt; RTI ID = 0.0 &gt; 500 C. &lt; / RTI &gt; The method according to claim 1,
Wherein the deposition step is performed by a chemical vapor deposition (CVD) method. The method according to claim 1,
In the deposition step, the ratio of the chalcogen-containing precursor partial pressure / transition metal-containing precursor partial pressure is increased to reduce the cluster size of the transition metal decalcogenide produced by the gas phase reaction and to reduce the surface energy of the substrate, Dimensional transition metal decalcogenide thin film, wherein the two-dimensional growth of the co-nitrogen is induced. 15. The method of claim 14,
In the deposition step, the amount of the carrier gas supplied into the deposition chamber is adjusted, or the temperature of the chalcogen-containing precursor and the transition metal-containing precursor supplied into the deposition chamber is controlled to control the chalcogen- Wherein the ratio of partial pressure of the chalcogen-containing precursor / partial pressure of the transition metal-containing precursor is controlled by controlling the amount of the transition metal-containing precursor. (1) reducing the surface energy of the substrate through surface treatment of the substrate in the deposition chamber;
(2) supplying a chalcogen-containing precursor and a transition metal-containing precursor into the deposition chamber at a temperature of 500 DEG C or less and a pressure of 0.001 Torr to 760 Torr to form crystals of two-dimensional transition metal dicalcium co- ;
(3) supplying a chalcogen-containing precursor and a transition metal-containing precursor into the deposition chamber to increase the crystal size of the two-dimensional transition metal dicalcium co-crystal on the substrate under an increased pressure than the pressure of step (2) ; And
(4) supplying a chalcogen-containing precursor and a transition metal-containing precursor into the deposition chamber under an increased pressure than the pressure of step (3) to form a two-dimensional transition metal decalcopyrite monolayer on the substrate; Lt; / RTI &gt;
A method for producing a two-dimensional transition metal decalcogenide thin film, wherein in step (2) to (4), an inhibitor is additionally provided to prevent generation of a two-dimensional transition metal dicalcogenide bilayer. 17. The method of claim 16,
A method for producing a two-dimensional transition metal decalcogenide thin film, wherein in steps (2) to (4), a precursor decomposition promoting catalyst is further supplied into the deposition chamber. delete

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