Gallium compound-containing composition for thin film deposition and method for manufacturing thin film using same

Abstract

The present invention relates to a gallium compound-containing composition for thin film deposition and a method for manufacturing a thin film using same. The gallium compound of the present invention is very useful as a precursor for a gallium-containing thin film due to having excellent volatility and stability, and can produce higher quality gallium-containing thin films due to having excellent adsorption to a substrate.

Description

Composition for thin film deposition containing gallium compound and method for producing thin film using same

[0001] The present invention relates to a composition for thin film deposition containing a gallium compound and a method for producing a thin film using the same, and more particularly, to a composition for thin film deposition containing a gallium compound useful as a precursor for thin film deposition containing gallium, and a method for producing a thin film containing gallium using the same.

[0002] The development of new technologies and materials in the semiconductor industry has enabled the miniaturization, high reliability, high speed, high functionality, and high integration of devices such as semiconductor integrated circuits. Consequently, the properties required for precursors for forming thin films have also changed. Generally, precursors for thin film deposition require compounds in gaseous or liquid form with high vapor pressure, excellent thermal stability, and easy transport into the deposition chamber. Furthermore, they must exhibit excellent reactivity with the reactive gases used, depending on the type of thin film being manufactured.

[0003] Thin film formation methods used in the manufacture of semiconductor devices include physical vapor deposition (PVD) and chemical vapor deposition (CVD) methods, both based on sputtering. However, in next-generation semiconductor manufacturing, uniform thin films are required even on the complex three-dimensional surfaces of miniaturized devices. Therefore, PVD, which has difficulty forming uniform films on uneven surfaces, is not suitable.

[0004] Accordingly, as a method for forming a thin film with excellent step coverage, a thin film formation method using a CVD method in which a raw material is transferred to a reaction tank as a gas and decomposed to form a film, or an atomic layer deposition (ALD) method in which a raw material adsorbed on a substrate surface is decomposed to deposit a film, is being studied and mainly used.

[0005] Meanwhile, precursors containing Group 13 metals are attracting attention as precursors for thin-film deposition due to their excellent stability and conductivity. In particular, Group 13 metal oxides can be used as transparent oxide semiconductor materials and are applicable to electrodes, conductive coating materials, and other applications.

[0006] Gallium oxide (Ga2O3), which contains gallium among the Group 13 metals, has a wide band gap energy and is used as a material applicable to display fields such as gas sensors and transparent conductors, as well as next-generation solar cells, specifically, phosphor raw materials, semiconductors, CIGS (copper indium gallium selenide) solar cells, thin-film transistor liquid crystal displays (TFT-LCDs), and organic light-emitting diodes (OLEDs). In addition, gallium oxide is an electrical insulator at room temperature and a semiconductor at temperatures above 500°C with a chemically and thermally stable monoclinic form.

[0007] Trimethylgallium (TMG) is the most widely used gallium precursor, but it is very sensitive to air and spontaneously combusts when exposed, making it difficult to handle. In addition, gallium complexes such as [Ga(hfac)]3 (hfac = hexafluoroacetylacetonate) and [Ga(OCH(CF3)2)3(HNMe2)] have been reported, but these contain halogen elements, especially fluorine. Therefore, gallium fluoride (GaF) is formed due to fluorine during thin film deposition, which causes contamination of the thin film, which can cause serious deterioration of device characteristics and reliability issues during the semiconductor device process. In addition, gallium alkoxide dimers or tetramers have been reported, but these do not correspond to single units, so they have low volatility for use as precursors for thin film deposition.

[0008] Precursors for thin film deposition are required to have high volatility and thermal stability, but previously reported gallium compounds have insufficient volatility to be used as precursors or contain halogen elements, which causes the thin film to be contaminated by the halogen elements.

[0009] Therefore, there is a need for the development of a precursor for deposition of gallium-containing thin films applicable to ALD and CVD processes that has low reactivity in moisture or air, no risk of spontaneous combustion, is easy to handle, does not contain halogen elements such as fluorine in the compound itself, and has high volatility and thermal stability.

[0010] The present invention provides a composition for deposition of a gallium-containing thin film comprising a gallium compound having improved volatility and thermal stability and being very useful for producing a high-quality gallium-containing thin film.

[0011] The present invention also provides a method for producing a gallium-containing thin film using a composition for depositing a gallium-containing thin film comprising the gallium compound of the present invention.

[0012] One aspect of the present invention provides a composition for deposition of a gallium-containing thin film, including a gallium compound represented by chemical formula 1, which is very useful as a precursor of a gallium-containing thin film due to its excellent volatility and stability, and a method for forming a gallium-containing thin film using the same.

[0013] [Chemical Formula 1]

[0014]

[0015] In the above chemical formula 1,

[0016] R 1 and R 2 are independently C1-C7 alkyl, hydrogen, C3-C20 cycloalkyl or C6-C20 aryl;

[0017] R 3 is hydrogen, C1-C7 alkyl or C6-C20 aryl;

[0018] R 4 and R 5are independently C1-C7 alkyl, C6-C20 aryl or -NR'R'';

[0019] R' is C1-C7 alkyl, R'' is hydrogen or C1-C7 alkyl;

[0020] The above R 1 Inland R 5 The aryl may be further substituted with C1-C7 alkyl or halogen.

[0021] Another aspect of the present invention provides a method for forming a gallium-containing thin film using a gallium compound represented by chemical formula 1 according to one embodiment.

[0022] The gallium compound according to the present invention has excellent thermal stability, high volatility, and excellent cohesion, making it useful as a precursor for a gallium-containing thin film, and further, excellent adsorption to a substrate allows for the production of a higher quality gallium-containing thin film. In addition, the novel gallium compound according to the present invention exists in a liquid state at room temperature and under a pressure that allows handling, making it easy to handle. In addition, since the novel gallium compound according to the present invention exists in a liquid state at room temperature, it can be supplied to a large-area substrate at a uniform concentration, resulting in excellent uniformity of the thin film thickness. In addition, the gallium compound according to the present invention does not decompose even at high process temperatures and has excellent storage stability.

[0023] Therefore, the composition for deposition of a gallium-containing thin film of the present invention includes a gallium compound having high thermal stability and reactivity as a precursor, thereby enabling the production of a uniform thin film of high density and high purity with excellent cohesion at a high deposition rate when producing a gallium-containing thin film.

[0024] In addition, the method for manufacturing a gallium-containing thin film of the present invention uses a gallium compound having high thermal stability and reactivity as a precursor, or manufactures a gallium-containing thin film using the composition for deposition of the gallium-containing thin film, thereby making it possible to manufacture a high-quality gallium-containing thin film with excellent thermal stability and durability.

[0025] Figure 1 is a TGA result spectrum of a gallium compound manufactured in Example 1 of the present invention.

[0026] Figure 2 is a DSC result spectrum of a gallium compound manufactured in Example 1 of the present invention.

[0027] Figure 3 shows the growth rate per cycle of a gallium-containing thin film manufactured in Example 5 of the present invention.

[0028] Figure 4 is an XPS result spectrum of a gallium-containing thin film manufactured in Example 5 of the present invention.

[0029] Hereinafter, the present invention will be described in more detail. Unless otherwise defined, the technical and scientific terms used herein have the meanings commonly understood by those of ordinary skill in the art to which this invention pertains. In the following description, descriptions of well-known functions and configurations that may unnecessarily obscure the gist of the present invention will be omitted.

[0030] As used herein, the singular forms may be intended to include the plural forms as well, unless the context clearly indicates otherwise.

[0031] As used herein, the term "includes" is an open-ended description equivalent to "comprises," "contains," "has," or "characterizes," and does not exclude additional elements, materials, or processes not listed herein.

[0032] The term "gallium compound" in this specification can be represented by Chemical Formula 1 and has an equivalent meaning to expressions such as "gallium precursor" or "gallium precursor compound."

[0033] The term "thermal stability" in this specification may mean that the physical properties do not change even during a continuous heating process or a high temperature process, and specifically means that the structural changes do not occur even when exposed for a long period of time under the harsh conditions described above.

[0034] As used herein, "alkyl" means a saturated straight-chain or branched non-cyclic hydrocarbon having 1 to 10 carbon atoms, preferably 1 to 6 carbon atoms, and more preferably 1 to 4 carbon atoms. "Lower alkyl" means a straight-chain or branched alkyl having 1 to 4 carbon atoms. Representative saturated straight-chain alkyls include methyl, ethyl, n-propyl, n-butyl, n-pentyl, n-hexyl, n-heptyl, n-octyl, n-nonyl and n-decyl, while saturated branched alkyls include isopropyl, sec-butyl, isobutyl, tert-butyl, isopentyl, 2-methylhexyl, 3-methylbutyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 2-methylhexyl, 3-methylhexyl, 2-methylpentyl, 3-methylpentyl, 4-methylpentyl, 2-methylhexyl, 3-methylhexyl, 4-methylhexyl, 5-methylhexyl, 2,3-dimethylbutyl, 2,3-dimethylpentyl, 2,4-dimethylpentyl, 2,3-dimethylhexyl, 2,4-dimethylhexyl, 2,5-dimethylhexyl, 2,2-dimethylpentyl, 2,2-dimethylhexyl, 3,3-dimethylpentyl, 3,3-dimethylhexyl, 4,4-dimethylhexyl, 2-ethylpentyl, 3-ethylpentyl, 2-deethylhexyl, 3-ethylhexyl, 4-ethylhexyl, 2-methyl-2-ethylpentyl, 2-methyl-3-ethylpentyl, 2-methyl-4-ethylpentyl, 2-methyl-2-ethylhexyl, 2-methyl-3-ethylhexyl, 2-methyl-4-ethylhexyl, 2,2-diethylpentyl, 3,3-diethylhexyl, 2,2-diethylhexyl, and 3,3-diethylhexyl.

[0035] When described as "C1-C10" in this specification, it means that the number of carbon atoms is 1 to 10. For example, C1-C4 alkyl means alkyl having 1 to 4 carbon atoms. Specific examples include methyl, ethyl, propyl, iso-propyl, butyl, iso-butyl, or tert-butyl.

[0036] The term "cycloalkyl" as used herein refers to a monovalent, saturated or unsaturated carbocyclic radical consisting of one or more rings, which is not aromatic. The cycloalkyl may be monocyclic or a fused, spiro, or bridged bicyclic ring system. The cycloalkyl may have 3 to 20 carbon atoms, preferably 3 to 10 carbon atoms, and more preferably 3 to 7 carbon atoms. Specifically, a monocyclic cycloalkyl ring contains 3 to 20 carbon atoms, preferably 3 to 7 carbon atoms, in the ring. Specific examples of cycloalkyl include, but are not limited to, cyclopropyl, cyclobutyl, cyclopentyl, and cyclohexyl.

[0037] The term “aryl” as used herein refers to a monovalent organic radical of an aromatic ring derived from an aromatic hydrocarbon by the removal of one hydrogen, including a single or fused ring system, suitably containing 6 to 20, preferably 6, ring atoms in each ring, and even including a form in which multiple aryls are connected by single bonds. Specific examples include, but are not limited to, phenyl, naphthyl, biphenyl, anthryl, indenyl, and fluorenyl.

[0038] The term “halogen” as used herein refers to a halogen group element, including, for example, fluoro, chloro, bromo, and iodo.

[0039] One aspect of the present invention provides a composition for deposition of a gallium-containing thin film, comprising a gallium compound represented by the following chemical formula 1, which has excellent reactivity and thermal stability and is easy to handle as it exists mostly in the form of a solid or liquid at room temperature, and is thus very useful as a precursor for a gallium-containing thin film.

[0040] [Chemical Formula 1]

[0041]

[0042] In the above chemical formula 1,

[0043] R1 and R 2 are independently C1-C7 alkyl, hydrogen, C3-C20 cycloalkyl or C6-C20 aryl;

[0044] R 3 is hydrogen, C1-C7 alkyl or C6-C20 aryl;

[0045] R 4 and R 5 are independently C1-C7 alkyl, C6-C20 aryl or -NR'R'';

[0046] R' is C1-C7 alkyl, R'' is hydrogen or C1-C7 alkyl;

[0047] The above R 1 Inland R 5 The aryl may be further substituted with C1-C7 alkyl or halogen.

[0048] In the above chemical formula 1 according to one specific example, R 1 and R 2 are independently C1-C5 alkyl, hydrogen, C3-C10 cycloalkyl or C6-C10 aryl; R 3 is C1-C5 alkyl; R 4 and R 5 are independently C1-C5 alkyl, C6-C10 aryl or -NR'R''; R' is C1-C5 alkyl, R'' is hydrogen or C1-C5 alkyl; and the R 1 Inland R 5 The aryl may be further substituted with C1-C5 alkyl or halogen.

[0049] In the above chemical formula 1 according to one specific example, R 1 and R 2 are independently C1-C5 alkyl, hydrogen, C3-C10 cycloalkyl or C6-C10 aryl; R 3 is C6-C10 aryl; R 4 and R 5are independently C1-C5 alkyl, C6-C10 aryl or -NR'R''; R' is C1-C5 alkyl, R'' is hydrogen or C1-C5 alkyl; and the R 1 Inland R 5 The aryl may be further substituted with C1-C5 alkyl or halogen.

[0050] In the above chemical formula 1 according to one specific example, R 1 and R 2 are independently C1-C5 alkyl; R 3 is hydrogen, C1-C5 alkyl or C6-C10 aryl; R 4 and R 5 are independently C1-C5 alkyl, C6-C10 aryl or -NR'R''; R' is C1-C5 alkyl, R'' is hydrogen or C1-C5 alkyl; and the R 1 Inland R 5 The aryl may be further substituted with C1-C5 alkyl or halogen.

[0051] In the above chemical formula 1 according to one specific example, R 1 and R 2 are independently C3-C10 cycloalkyl or C6-C10 aryl; R 3 is hydrogen, C1-C5 alkyl or C6-C10 aryl; R 4 and R 5 are independently C1-C5 alkyl, C6-C10 aryl or -NR'R''; R' is C1-C5 alkyl, R'' is hydrogen or C1-C5 alkyl; and the R 1 Inland R 5 The aryl may be further substituted with C1-C5 alkyl or halogen.

[0052] In the above chemical formula 1 according to one specific example, R 1 and R 2 are independently C1-C5 alkyl, hydrogen, C3-C10 cycloalkyl or C6-C10 aryl; R 3 is hydrogen, C1-C5 alkyl or C6-C10 aryl; R 4 and R5 are independently C1-C5 alkyl; and R 1 Inland R 5 The aryl may be further substituted with C1-C5 alkyl or halogen.

[0053] In the above chemical formula 1 according to one specific example, R 1 and R 2 are independently C1-C5 alkyl, hydrogen, C3-C10 cycloalkyl or C6-C10 aryl; R 3 is hydrogen, C1-C5 alkyl or C6-C10 aryl; R 4 and R 5 are independently C6-C10 aryl; and R 1 Inland R 5 The aryl may be further substituted with C1-C5 alkyl or halogen.

[0054] In the above chemical formula 1 according to one specific example, R 1 and R 2 are independently C1-C5 alkyl, hydrogen, C3-C10 cycloalkyl or C6-C10 aryl; R 3 is hydrogen, C1-C5 alkyl or C6-C10 aryl; R 4 and R 5 are independently -NR'R''; R' is C1-C5 alkyl, R'' is hydrogen or C1-C5 alkyl; and the R 1 Inland R 5 The aryl may be further substituted with C1-C5 alkyl or halogen.

[0055] The gallium compound of the present invention has a heterocyclic structure containing at least two nitrogen atoms in gallium (Ga), which is a central metal. By introducing a specific structure, thermal stability and reactivity are significantly improved, and at the same time, volatility is high, enabling the production of a high-quality thin film.

[0056] In addition, since the gallium compound of the present invention exists in a liquid form at room temperature and pressure, it has high storage stability and excellent volatility, and can be used as a precursor for deposition of a gallium-containing thin film to produce a high-density, high-purity gallium-containing thin film.

[0057] In one embodiment, the R in the chemical formula 1 1 and R 2 are independently C1-C7 alkyl; R 3 is hydrogen or C1-C7 alkyl; R 4 and R 5 can be independently C1-C7 alkyl.

[0058] In one embodiment, the R in the chemical formula 1 1 and R 2 are independently C1-C5 alkyl; R 3 is hydrogen or C1-C5 alkyl; R 4 and R 5 can be independently C1-C5 alkyl.

[0059] In one embodiment, the R in the chemical formula 1 1 and R 2 are identical to each other and are C3-C7 alkyl of the grinding; R 3 is hydrogen or C1-C7 alkyl; R 4 and R 5 can be independently C1-C7 alkyl.

[0060] In one embodiment, the R in the chemical formula 1 1 and R 2 are identical to each other and are C3-C7 alkyl of the grinding; R 3 is hydrogen or C1-C5 alkyl; R 4 and R 5 can be independently C1-C5 alkyl.

[0061] In one specific example, the R 1 and R 2 are identical to each other, isopropyl or tert-butyl; R 3Inland R 5 can be methyl or ethyl.

[0062] Specifically, the gallium compound according to one embodiment may be selected from the compounds below, but is not limited thereto.

[0063]

[0064]

[0065]

[0066] The composition for thin film deposition according to one embodiment may be specifically for indium gallium zinc oxide (IGZO) thin film deposition.

[0067] In addition to the gallium compound described above, an indium precursor and a zinc precursor may be further included.

[0068] The indium precursor may be a C1-C6 alkylindium, the zinc precursor may be a C1-C6 alkylzinc, and specifically, the indium precursor may be trimethylindium (TMI), and the zinc precursor may be diethylzinc (DEZ), but is not limited thereto.

[0069] The molar ratio of the above indium precursor: gallium precursor: zinc precursor may be 1 to 10:1 to 10:1 to 10, specifically 1 to 5:1 to 5:1 to 5, and more specifically 1:1:1.

[0070] Another aspect of the present invention provides a method for forming a gallium-containing thin film using a gallium compound represented by chemical formula 1 according to one embodiment.

[0071] The method for manufacturing the above gallium-containing thin film may be a conventional method used in the art, specifically, atomic layer deposition (ALD), chemical vapor deposition (CVD), metalorganic chemical vapor deposition (MOCVD), low pressure chemical vapor deposition (LPCVD), plasma enhanced chemical vapor deposition (PECVD), or plasma enhanced atomic layer deposition (PEALD).

[0072] More preferably, the method for manufacturing the gallium-containing thin film according to one embodiment may be atomic layer deposition (ALD), chemical vapor deposition (CVD), metalorganic chemical vapor deposition (MOCVD), etc.

[0073] In one embodiment, the gallium-containing thin film of the present invention can be manufactured by atomic layer deposition (ALD).

[0074] A method for manufacturing a gallium-containing thin film according to one embodiment includes a step of depositing the gallium compound on a substrate to form a thin film, and specifically, may include a) a step of adsorbing the gallium compound on the substrate; b) a step of purging unadsorbed gallium compound; c) a step of injecting a reaction gas to form a gallium-containing thin film; and d) a step of purging residual reaction gas and reaction byproducts.

[0075] A method for manufacturing a gallium-containing thin film according to one embodiment may include a step of depositing at least one selected from the gallium compound and an indium precursor and a zinc precursor on a substrate to form a single-layer or multi-layer thin film, and the gallium compound, the indium precursor and the zinc precursor may be deposited simultaneously on the substrate, or the gallium compound, the indium precursor and the zinc precursor may be mixed and then deposited on the substrate to form a thin film having a single-layer structure, and the indium precursor, the gallium compound and the zinc precursor may be sequentially deposited on the substrate to form a thin film having a multi-layer structure. Specifically, the indium precursor may be trimethylindium (TMI), and the zinc precursor may be diethylzinc (DEZ), but is not limited thereto. The above multilayered thin film may be an indium-gallium-zinc oxide film (IGZO thin film), and the composition ratio of indium:gallium:zinc may be 1 to 10:1 to 10:1 to 10, specifically 1 to 5:1 to 5:1 to 5, and more specifically 1:1:1.

[0076] A gallium-containing thin film according to one embodiment is manufactured using the gallium compound, and is preferably, but not limited to, a gallium nitride film, a gallium oxide film, or an indium-gallium-zinc oxide film, and is preferably a gallium oxide film or an indium-gallium-zinc oxide film.

[0077] The method for manufacturing a gallium-containing thin film of the present invention is performed by using the gallium compound of the present invention, which has high volatility and thermal stability, as a precursor, so that the manufactured gallium-containing thin film has extremely excellent physical, electrical, and chemical properties.

[0078] In a method for manufacturing a gallium-containing thin film according to one embodiment, the injection temperature of the gallium compound of the present invention may be room temperature (25°C) to 120°C, and due to the high volatility of the gallium compound of the present invention, the temperature of the substrate on which the gallium compound is to be deposited may be 100 to 450°C, and the pressure inside the chamber may be 0.1 to 10 torr.

[0079] In a method for manufacturing a gallium-containing thin film according to one embodiment, the reaction gas used is not limited, but one or more mixed gases selected from hydrogen (H2), hydrazine (N2H4), dimethylhydrazine (Me2N2H2), ozone (O3), oxygen (O2), water (H2O), ammonia (NH3), nitrogen (N2), silane (SiH4), borane (BH3), diborane (B2H6), and phosphine (PH3) may be used, and the reaction gas is not limited, but may be supplied at a flow rate of 10 to 10,000 sccm, and specifically, may be supplied at a flow rate of 50 to 1,000 sccm.

[0080] Specifically, when deposition is performed in the presence of an oxidizing reaction gas such as water vapor (H2O), oxygen (O2), or ozone (O3), a gallium oxide film can be formed, and when deposition is performed in the presence of a nitrogen-containing reaction gas such as ammonia (NH3) or hydrazine (N2H4), a gallium nitride film can be formed.

[0081] The above purge gas is an inert gas, and is not limited thereto, but may be one or more mixed gases selected from argon (Ar) and nitrogen (N2).

[0082] In a method for manufacturing a gallium-containing thin film according to one embodiment, the substrate used may be, but is not limited to, a substrate including one or more semiconductor materials selected from the group consisting of Si, SiO2, Pt, TiN, Ge, SiGe, GaP, GaAs, SiC, SiGeC, InAs, and InP; a silicon-on-insulator (SOI) substrate; a quartz substrate; or a glass substrate for a display; a flexible plastic substrate selected from the group consisting of polyimide, polyethylene terephthalate (PET), polyethylene naphthalate (PEN), polymethyl methacrylate (PMMA), polycarbonate (PC), polyethersulfone (PES), polyester, and the like; and the like.

[0083] A method for manufacturing a gallium-containing thin film according to one embodiment has high volatility and high thermal stability, and by using it as a precursor for thin film deposition, a high-quality, uniform gallium-containing thin film with excellent physical, electrical and chemical properties can be formed with high density and high purity.

[0084] Hereinafter, the composition of the present invention will be described in more detail through examples, but the following examples are intended to help understanding of the present invention, and the scope of the present invention is not limited thereto.

[0085] The synthesis of gallium compounds according to the present invention was carried out using a standard Schlenk flask or purge box under an inert argon or nitrogen atmosphere, except where otherwise noted. 1The structure of the obtained gallium compound was analyzed through H NMR spectrum and elemental analysis. In addition, the thickness of the deposited gallium-containing thin film was measured using an ellipsometer (Ellipsometer, Thermowave, Optiprobe 2600), and the composition of the thin film was analyzed using X-ray photoelectron spectroscopy (XPS, X-ray Photoelectron Spectroscopy, ThermoFisher Scientific, K-Alpha+).

[0086] [Example 1] Synthesis of gallium compound 1

[0087]

[0088] Two 1000ml Schlenk flasks and one 250ml Schlenk flask dried in an oven were placed in a purge box and purged for more than 30 minutes to remove as much moisture as possible from the inside of the glass.

[0089] In a purge box, 50 g (0.3962 mol) of N,N'-Diisopropylcarbodiimide (DIC) was added to a 1000 ml schlenk flask (A), and 158 ml (0.3962 mol) of 1.6 M methyl lithium in diethyl ether was added to a 250 ml schlenk flask (B). Then, each flask was moved to the hood.

[0090] The flask (A) was placed in an ice bath below 0℃, and 300 ml of Ether was added while blowing nitrogen.

[0091] Install a thermometer inside the flask (A) to check whether the solution temperature drops below 0℃, and pressurize and transfer the MeLi solution in the flask (B) to the flask (A) at a temperature below 0℃. At this time, add slowly while checking the thermometer.

[0092] After pressurized transfer is completed, 30 ml of Ether is added to flask (B), washed, and pressurized transfer is performed twice more to flask (A). Afterwards, the product is separated through a filter at room temperature and vacuum dried to remove any remaining solvent.

[0093] The yield of the synthesized intermediate was 50%, and the synthesized intermediate was measured by NMR using THF-d8 solvent, and the measurement results were as follows: 0.9417 ppm (d, 12H), 1.7320 ppm (s, 3H), 3.4317 ppm (broad s, 2H).

[0094] Next, the oven-dried 500 ml schlenk flask and 250 ml schlenk flask were placed in a purge box and purged for more than 30 minutes to remove as much moisture as possible inside the glass.

[0095] In a purge box, 20 g (0.1350 mol) of vacuum-dried intermediate was added to a 500 ml schlenk flask (A), and 18.3 g (0.1350 mol) of dimethylgallium chloride was added to a 250 ml schlenk flask (B). Each flask was then moved to the hood.

[0096] Flask (A) was placed in an ice bath below 0℃, and 200 ml of toluene was added while blowing nitrogen. In the same way, 50 ml of toluene was added to flask (B) to dissolve dimethylgallium chloride.

[0097] Install a thermometer inside flask (A) to check if the solution temperature drops below 0℃, and then pressurize and transfer the solution in flask (B) to flask (A) at a temperature below 0℃. At this time, add slowly while checking the thermometer.

[0098] After the pressurized transfer is completed, 30 ml of toluene is added to the flask (B), washed, and then pressurized twice to the flask (A). Afterwards, the salt is removed by filtration at room temperature, and the solution is removed through drying. Afterwards, the mixture was purified by distillation (Bottom temp: 53°C, Top temp: 43.8°C, Pressure 672 mtorr (Converted temperature: 213.6°C)), and a pale yellow liquid, gallium compound 1, was obtained (51.51 g, 57.8%).

[0099] The NMR data of the obtained gallium compound measured with THF-d8 are as follows.

[0100] 0.163ppm (s, 6H), 0.9682ppm (d, 12H), 1.3439ppm (s, 3H), 3.2827ppm (m, 2H)

[0101] [Example 2] Synthesis of gallium compound 2

[0102]

[0103] Except that N,N′3g (0.0194 mol) was used instead of 50g (0.3962mol) of N,N'-Diisopropylcarbodiimide (DIC) in Example 1, MeLi 1.6M in diethyl ether 12.7ml (0.0194 mol) was used instead of 158ml (0.3962mol) of 1.6M methyl lithium in diethyl ether, the amount of the synthesized intermediate was 1.3g (0.0084mol), and DimethylGallium chloride 1.1g (0.0084mol) was used instead of 18.3g (0.1350mol), the reaction was carried out in the same manner as in Example 1 to obtain gallium compound 2 as a pale yellow liquid (51.53g, 51.8%).

[0104] The synthesized intermediate was measured by NMR using THF-d8 solvent, and the measurement results are as follows: 0.9417 ppm (d, 12H), 1.7320 ppm (s, 3H), 3.4317 ppm (broad s, 2H).

[0105] In addition, the NMR data of the obtained gallium compound 2 measured with THF-d8 are as follows.

[0106] 0.1294ppm (s, 6H), 1.1060ppm (s, 18H), 1.7307ppm (s, 3H)

[0107] [Experimental Example 1] Material Analysis of Gallium Compounds

[0108] In order to measure the thermal stability and decomposition temperature of the gallium compound 1 manufactured in Example 1, thermogravimetric analysis (TGA) was used (TGA conditions: heating to 300°C at a rate of 10°C / min while injecting argon at a pressure of 1.5 bar / min). The graph of the TGA analysis results is shown in Fig. 1, and as shown in Fig. 1, the gallium compound of Example 1 showed a mass decrease starting around 60°C, and a mass decrease of more than 100% was confirmed around 260°C. Based on the low purification temperature and the TGA results, it can be seen that the manufactured gallium compound has high volatility.

[0109] In addition, the results of analysis using differential scanning calorimetry (DSC) are shown in Fig. 2, and it was confirmed that the gallium compound manufactured with a decomposition temperature of 230°C or higher had excellent thermal stability.

[0110] [Examples 3 to 7] Preparation of gallium-containing thin films

[0111] The gallium compound 1 prepared in Example 1 was used as a precursor for a gallium-containing thin film as a composition for forming a thin film, ozone (O3) was used as a reaction gas, the concentration of ozone was 200 g / ㎥, and argon (Ar) was used as a carrier gas and purge gas to form a gallium-containing thin film by atomic layer deposition (ALD).

[0112] A silicon oxide film was used as a substrate. The silicon oxide film substrate was loaded into the deposition chamber, and the substrate temperature was set to 250°C. To appropriately maintain the vapor pressure of the gallium compound and prevent condensation, gallium compound 1 was layered in a stainless steel bubbler and maintained at 30°C. The flow rate of the ozone (O3) as a reaction gas was fixed at 200 sccm, the flow rate of the carrier gas (Ar) was fixed at 50 sccm, the flow rate of the purge gas (Ar) was fixed at 50 sccm, and the process pressure was maintained at 1 Torr. The thin film deposition using a gallium precursor was performed by repeating 100 cycles of four sequential steps of gallium precursor injection - purge (Ar) - ozone (O3) injection - purge (Ar), which were considered as one cycle, to deposit a gallium-containing thin film. The detailed deposition conditions and results are shown in Table 1 below.

[0113] Example 34567 Process pressure (Torr) 11111 Silicon substrate temperature (℃) 250 250 250 250 250 Gallium precursor heating temperature (℃) 30 30 30 30 30 Injection time (sec) 135 10 20 Purge (Ar) flow rate (sccm) 50 50 50 50 50 Hours (sec) 20 20 20 20 20 Ozone (O3) flow rate (sccm) 20 20 0 20 0 20 0 20 0 Hours (sec) 20 20 20 20 20 Transport (Ar) flow rate (sccm) 50 50 50 50 50 Hours (sec) 55 55 Number of deposition cycles 100 100 100 100 100 Thin film thickness (Å) 86 123 13 11 27 135 GPC (Å) 0.86 1.23 1.31 1.27 1.35

[0114] The growth per cycle (GPC) rate according to the injection time of gallium compound 1 was measured and shown in Table 1. The gallium precursor according to the present invention showed an increase in GPC up to an injection time of 1 to 3 seconds, and maintained a constant level of GPC from an injection time of 4 seconds, confirming that the growth rate of the gallium-containing thin film was constant as saturation occurred from an injection time of 4 seconds of the gallium precursor. Hereinafter, the specific ellipsometry analysis results are shown in Fig. 3.

[0115] [Comparative Example 1] Fabrication of a gallium-containing thin film

[0116] A gallium-containing thin film was deposited in the same manner as in Example 5, except that trimethylgallium (TMG) was used as a precursor for depositing a gallium-containing thin film.

[0117] The XPS analysis results of the gallium-containing thin film manufactured in Example 5 are shown in Table 2 below and illustrated in Fig. 4. Table 2 shows the content values ​​of each atom in the thin film based on the composition analyzed using an X-ray photoelectron spectrometer for the manufactured gallium-containing thin film.

[0118] Atomic % Comparative Example 1 Example 5C1s5.48.8Ga3d39.937.8O1s54.753.3Ga:O Ratio 1: 1.371: 1.41

[0119] From Table 2, the gallium content and oxygen content of the gallium-containing thin film manufactured in Example 5 were measured to be 32.3% and 40.7%, respectively, confirming that a gallium oxide film was substantially formed.

[0120] In addition, the gallium-to-oxygen atomic ratio was 1:1.41, which was very close to the theoretical value of 1 to 1.5, which is the stoichiometric ratio of gallium elements and oxygen elements, compared to the gallium-containing thin film (Ga:O = 1:1.37) manufactured using TMG of Comparative Example 1. In addition, the XPS analysis result for the gallium-containing thin film manufactured in Example 8 confirmed a binding energy (eV) similar to that of Ga2O3 described in the known literature [J. Mater. Chem. C, 2019, 7, 69-77] (Fig. 4). That is, it can be seen that when the gallium compound according to the present invention is used as a precursor, a gallium-containing thin film with higher purity is manufactured. On the other hand, when the known material TMG was used, a thin film deposition result similar to that of the example of the present invention was shown, but the XPS analysis result confirmed that the purity of the thin film was lower than that of the example of the present invention. Hereinafter, the XPS result of Example 3 is shown in Fig. 4.

[0121] The gallium compound according to the present invention has excellent thermal stability and volatility, making it useful as a precursor for a gallium-containing thin film. Since it exists in a liquid state at room temperature, it can be supplied at a uniform concentration to a large-area substrate, and thus the uniformity of the thin film thickness is excellent, enabling the easy production of a high-density and high-purity gallium-containing thin film.

[0122] The foregoing description of the present invention is provided for illustrative purposes only. Those skilled in the art will readily appreciate that the present invention can be readily modified into other specific forms without altering the technical spirit or essential characteristics of the present invention. Therefore, the embodiments described above should be understood as illustrative in all respects and not restrictive.

Claims

1. A composition for deposition of a gallium-containing thin film comprising a gallium compound represented by the following chemical formula 1. [Chemical Formula 1] In the above chemical formula 1, R 1 and R 2 are independently C1-C7 alkyl, hydrogen, C3-C20 cycloalkyl or C6-C20 aryl; R 3 is hydrogen, C1-C7 alkyl or C6-C20 aryl; R 4 and R 5 are independently C1-C7 alkyl, C6-C20 aryl or -NR'R''; R' is C1-C7 alkyl, R'' is hydrogen or C1-C7 alkyl; The above R 1 Inland R 5 The aryl may be further substituted with C1-C7 alkyl or halogen.

2. In paragraph 1, The above R 1 and R 2 are independently C1-C7 alkyl; R 3 is hydrogen or C1-C7 alkyl; R 4 and R 5 A composition for deposition of a gallium-containing thin film, wherein each independently represents a C1-C7 alkyl.

3. In paragraph 1, The above R 1 and R 2 are identical to each other and are C3-C7 alkyl of the grinding; R 3 is hydrogen or C1-C7 alkyl; R 4 and R 5 A composition for deposition of a gallium-containing thin film, wherein each independently represents a C1-C7 alkyl.

4. In paragraph 1, A composition for deposition of a gallium-containing thin film, wherein the gallium compound is selected from the following compounds.

5. A method for forming a gallium-containing thin film using a composition for deposition of a gallium-containing thin film selected from any one of claims 1 to 4.

6. A method for manufacturing a gallium-containing thin film, comprising the step of forming a thin film by depositing a gallium compound represented by the following chemical formula 1 on a substrate. [Chemical Formula 1] In the above chemical formula 1, R 1 and R 2 are independently C1-C7 alkyl, hydrogen, C3-C20 cycloalkyl or C6-C20 aryl; R 3 is hydrogen, C1-C7 alkyl or C6-C20 aryl; R 4 and R 5 are independently C1-C7 alkyl, C6-C20 aryl or -NR'R''; R' is C1-C7 alkyl, R'' is hydrogen or C1-C7 alkyl; The above R 1 Inland R 5 The aryl may be further substituted with C1-C7 alkyl or halogen.

7. In paragraph 6, A method for manufacturing a gallium-containing thin film, comprising the step of forming a thin film by depositing the gallium compound and at least one selected from an indium precursor and a zinc precursor on a substrate.

8. In paragraph 6, A method for manufacturing a gallium-containing thin film, wherein the above deposition is performed by chemical vapor deposition (CVD) or atomic layer deposition (ALD).

9. In paragraph 6, A method for producing a gallium-containing thin film, wherein the gallium-containing thin film is a gallium oxide thin film, a gallium thin film, a gallium nitride thin film or an indium gallium zinc oxide (IGZO) thin film.

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