Thin film forming precursor, its manufacturing method, and thin film manufacturing method including the same

Abstract

The present invention relates to a precursor for forming a thin film, a method for producing the precursor, and a method for producing a thin film including the precursor. More specifically, the present invention relates to a precursor that is liquid under conditions of 20°C and 1 bar, and that contains 20 to 100% by weight of a coordination compound represented by the following chemical formula 1 and 0 to 80% by weight of an alkyl cyanide having 1 to 15 alkyl carbon atoms. [Chemical formula 1]MXnLmYz (M is niobium (Nb), tungsten (W) or molybdenum (Mo), X is a halogen element, n is an integer of 1 to 6, L is an alkyl cyanide having an alkyl carbon number of 1 to 15 or a linear or cyclic saturated hydrocarbon having a carbon number of 3 to 15 and substituted with one or more nitrogen (N), oxygen (O), phosphorus (P) or sulfur (S), m is an integer of 1 to 3, the bonded Y is an amine, z is an integer of 0 to 4, and n+z is an integer of 3 to 6.) According to the present invention, the compound is in a liquid state at room temperature, has high volatility, has a very fast deposition rate, is easy to handle when injected into a thin film deposition chamber, and has the effect of producing a thin film that is particularly excellent in thermal stability, high in purity, and excellent in step coverage.

Description

[Technical field]

[0001] The present invention relates to a precursor for forming a thin film, a manufacturing method thereof, and a method for manufacturing a thin film including the precursor. More specifically, the present invention relates to a precursor for forming a thin film that is in a liquid state at room temperature, has high volatility, has a very fast deposition rate, is easy to handle when injected into a thin film deposition chamber, and is particularly excellent in thermal stability, and can be used to manufacture a thin film that has high purity and excellent step coverage, a manufacturing method thereof, and a method for manufacturing a thin film including the precursor. [Background technology]

[0002] Through the use of thin film deposition technologies such as chemical vapor deposition (CVD) and atomic layer deposition (ALD), the size of semiconductor devices is becoming smaller and the integration density of devices is rapidly increasing.

[0003] However, in the chemical vapor deposition technique, all of the raw materials required for thin film formation are simultaneously supplied into the deposition chamber, making it difficult to form a film with the desired composition ratio and physical properties, and deposition is performed at high temperatures, which may lead to deterioration of semiconductor devices and a decrease in storage capacity.

[0004] In addition, the atomic layer deposition technique can independently supply raw materials required for thin film formation to form a film having desired composition ratios and properties, but there are many limitations on the types of precursors for thin film formation. In particular, when metal chlorides are used as precursors for thin film formation, dielectric films and the like may be damaged, resulting in deterioration of leakage current.

[0005] Niobium oxide (Nb 2 O 5Thin films of niobium nitride (NbN) have a high dielectric constant and are used not only as a component of ferroelectric materials but also as a core material for highly integrated non-volatile memories. Thin films of niobium nitride (NbN) are widely used in the semiconductor field because they provide a high work function in the fine patterns of semiconductor devices.

[0006] The thin film precursor commonly used to produce the niobium thin film is Nb(OR). 5 (R is alkyl). However, this precursor for thin film formation has the disadvantages of high viscosity and low hydrolysis resistance, and the alkoxide ligand easily dissociates, which causes side reactions in which oligomers and polymers are produced by heat, resulting in reduced volatility, slower thin film formation speed, and changes in the composition of the thin film.

[0007] In addition, Nb(NMe 2 ) 5 Although this material has relatively excellent sublimation properties, it is in a solid form and is less volatile than liquid thin film precursors. It also has problems such as poor thermal stability and poor hydrolysis resistance, being easily decomposed at temperatures above 150°C.

[0008] Therefore, there is a need to develop a precursor for forming a thin film that can produce a niobium thin film that is liquid at room temperature, highly volatile, has excellent thermal stability, and is excellent in both the thin film formation speed and physical properties of the thin film. [Prior art documents] [Patent documents]

[0009] [Patent Document 1] Korean Patent Publication No. 2001-0038063 Summary of the Invention [Problem to be solved by the invention]

[0010] In order to solve the above-mentioned problems of the conventional technology, the present invention aims to provide a precursor for forming a thin film, which is in a liquid state at room temperature, has high volatility, has a very fast deposition rate, is easy to handle when injected into a thin film deposition chamber, and can be used to form a thin film having excellent thermal stability, high purity, and excellent step coverage, a method for manufacturing the precursor, and a method for manufacturing a thin film including the precursor.

[0011] The above and other objects of the present invention can be achieved by the present invention described below. [Means for solving the problem]

[0012] In order to achieve the above object, the present invention provides a precursor for forming a thin film, which is liquid under conditions of 20°C and 1 bar, and contains 20 to 100% by weight of a coordination compound represented by the following chemical formula 1, and 0 to 80% by weight of an alkyl cyanide having an alkyl carbon number of 1 to 15.

[0013] [Chemical formula 1] MXnLmYz

[0014] (M is niobium (Nb), tungsten (W) or molybdenum (Mo), X is a halogen element; n is an integer of 1 to 6; L is an alkyl cyanide having an alkyl carbon number of 1 to 15 or a linear or cyclic saturated hydrocarbon having a carbon number of 3 to 15 and substituted with one or more nitrogen (N), oxygen (O), phosphorus (P) or sulfur (S), m is an integer of 1 to 3, the bonded Y is an amine, z is an integer of 0 to 4, and n+z is an integer of 3 to 6.)

[0015] The present invention also provides a method for producing a precursor for forming a thin film, comprising the step of reacting a compound represented by the following chemical formula 2 with an alkyl cyanide having an alkyl carbon number of 1 to 15, or a linear or cyclic saturated hydrocarbon having a carbon number of 3 to 15 and substituted with one or more of nitrogen (N), oxygen (O), phosphorus (P) or sulfur (S) in an organic solvent to synthesize a coordination compound represented by the chemical formula 1:

[0016] [Chemical formula 2] MX a Y (6-a)

[0017] (M is niobium (Nb), tungsten (W) or molybdenum (Mo), X is a halogen element, Y is an amine, and a is an integer of 1 to 6.)

[0018] The present invention also provides a method for producing a thin film, including the steps of injecting a precursor for forming a thin film according to the present invention into a CVD chamber or an ALD chamber and adsorbing the precursor on a surface of a loaded substrate; purging remaining unadsorbed precursor for forming a thin film with a purge gas; supplying a reaction gas to react with the precursor for forming a thin film adsorbed on the surface of the substrate to form a metal thin film layer; and purging reaction by-products with a purge gas. Effect of the Invention

[0019] According to the present invention, there are provided a precursor for forming a thin film which is in a liquid state at room temperature, has high volatility, has a very fast deposition rate, is easy to handle when injected into a thin film deposition chamber, and is capable of producing a thin film which has excellent thermal stability, high purity, and excellent step coverage, a method for producing the precursor, and a thin film production method including the precursor. [Brief description of the drawings]

[0020] [Figure 1] FIG. 1 is a process diagram illustrating an ALD process according to one embodiment of the present invention. [Diagram 2]3 is a photograph of the thin film precursor produced in Example 1 of the present invention taken before and after drying. [Diagram 3] 1 is a graph obtained by DSC analysis of the thin film precursor produced in Example 1 of the present invention. [Figure 4] 1 is a graph obtained by TGA analysis of a thin film-forming precursor produced in Example 1 of the present invention. [Diagram 5] 3 shows NMR spectra of the thin film precursor produced in Example 1 of the present invention, measured before and after leaving the precursor at 150° C. for 1 hour. [Figure 6] 4 is a graph obtained by DSC analysis of the thin film precursor produced in Example 2 of the present invention. [Figure 7] 4 is a graph obtained by TGA analysis of the thin film-forming precursor produced in Example 2 of the present invention. [Figure 8] 3 shows NMR spectra of the thin film precursor produced in Example 2 of the present invention, measured before and after leaving the precursor at 150° C. for 1 hour. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0021] The present thin film precursor, its manufacturing method, and thin film manufacturing method including the same will be described in detail below.

[0022] The inventors have confirmed that when niobium metal or the like is coordinated to a specific ligand, it is liquid at room temperature or can be easily liquefied with a specific solvent. Furthermore, they have confirmed that when such coordinated metal compounds are used as thin film forming precursors to form metal thin films, they are liquid at room temperature, have high volatility, have a very fast deposition rate, are easy to handle when injected into a thin film deposition chamber, and produce thin films that are particularly excellent in thermal stability, high purity, and step coverage. Based on this, they have pursued further research and have completed the present invention.

[0023] The thin film-forming precursor of the present invention is liquid under conditions of 20° C. and 1 bar,

[0024] [Chemical formula 1] MXnLmYz

[0025] (M is niobium (Nb), tungsten (W) or molybdenum (Mo), X is a halogen element, n is an integer of 1 to 6, L is an alkyl cyanide having an alkyl carbon number of 1 to 15 or a linear or cyclic saturated hydrocarbon having a carbon number of 3 to 15 and substituted with one or more nitrogen (N), oxygen (O), phosphorus (P) or sulfur (S), m is an integer of 1 to 3, the bonded Y is an amine, z is an integer of 0 to 4, and n+z is an integer of 3 to 6). and 0 to 80% by weight of an alkyl cyanide having an alkyl carbon number of 1 to 15. When a metal thin film is produced using such a thin film-forming precursor, it has the advantages of being easy to handle when injected into a thin film deposition chamber because it is in a liquid state at room temperature, highly volatile, has a very fast deposition rate, and its viscosity and vapor pressure can be easily adjusted, and in particular, it produces a thin film that has excellent thermal stability, is not easily decomposed, is high purity, and has excellent step coverage.

[0026] As another example, in the above Chemical Formula 1, n is an integer of 2 to 4, m is an integer of 1 to 3, z is an integer of 1 to 3, and n+m+z is 6.

[0027] In the coordination compound, X is preferably fluorine, n is preferably 5, and m is preferably 1. In this case, the coordination compound is in a liquid state at room temperature, and has the advantages of being highly volatile but having excellent thermal stability, a high deposition rate and ease of handling, and excellent thin film purity and step coverage.

[0028] In the coordination compound, L is preferably an alkyl cyanide having an alkyl carbon number of 1 to 5, more preferably an alkyl cyanide having an alkyl carbon number of 3 to 5, and has the advantage of being easily liquefied within this range.

[0029] As another example, L in the coordination compound may be a linear or cyclic saturated hydrocarbon having preferably 3 to 10 carbon atoms and substituted with one or more nitrogens (N) or oxygens (O), more preferably 4 to 8 carbon atoms and substituted with one or more nitrogens (N) or oxygens (O). Specific examples of L include diethyl ether and tetrahydrofuran, and within this range, there is an advantage that the thin film-forming precursor can be easily liquefied.

[0030] In this description, a saturated hydrocarbon is substituted with one or more nitrogen (N), oxygen (O), phosphorus (P) or sulfur (S) means that the nitrogen (N), oxygen (O), phosphorus (P) or sulfur (S) is inserted between atoms of the saturated hydrocarbon or is bonded to a hydrogen atom, a carbon atom, a CH group or a CH 2 The group may be substituted with .

[0031] The L preferably acts as a ligand.

[0032] In the coordination compound, Y is preferably a secondary amine, more preferably a dialkylamine, and specific examples thereof include one or more selected from the group consisting of diethylamine, dimethylamine, ethylmethylamine, dipropylamine, etc., and has the advantage of being easily liquefied within this range.

[0033] The coordination compound may be represented by the following chemical formula 1a as a preferred example, and more preferably 1b. In this case, when a metal thin film is produced using the precursor for forming a thin film, the precursor is in a liquid state at room temperature and has high volatility, has a very fast deposition rate, and the viscosity and vapor pressure can be easily adjusted. It is easy to handle when injected into a thin film deposition chamber. In particular, the precursor has excellent thermal stability and is not easily decomposed, so that a thin film having high purity and excellent step coverage can be produced.

[0034] [Chemical formula 1a] MXnLmYz

[0035] (M is niobium (Nb), tungsten (W) or molybdenum (Mo), X is a halogen element, n is an integer of 1 to 6, L is an alkyl cyanide having an alkyl carbon number of 1 to 15, m is an integer of 1 to 3, Y is an amine, z is an integer of 0 to 4, and n+m+z is 6.)

[0036] [Formula 1b] MXnLm

[0037] (M is niobium (Nb), tungsten (W) or molybdenum (Mo), X is a halogen element, n is an integer of 3 to 6, L is an alkyl cyanide having an alkyl carbon number of 1 to 15, m is an integer of 1 to 3, and n+m is 6.)

[0038] In yet another example, n can be an integer from 3 to 5.

[0039] The thin film precursor preferably has a final temperature (Tf) of 180°C or higher, more preferably 180 to 250°C, and even more preferably 190 to 230°C, as measured by a thermogravimetric analyzer (TGA). Within this range, the thin film precursor has the effect of exhibiting excellent purity and excellent step coverage.

[0040] The precursor for forming a thin film has a residue measured by a thermogravimetric analyzer (TGA) of preferably less than 3% by weight, more preferably 2% by weight or less, even more preferably 2% by weight or less, and most preferably 1% by weight or less, and has the advantage of having excellent thermal stability within this range.

[0041] The thin film precursor has an exothermic temperature measured by a differential scanning calorimeter (DSC) of preferably 150°C or higher, more preferably 150 to 230°C, and even more preferably 160 to 210°C, and has the effect of exhibiting excellent thermal stability within this range.

[0042] The method for producing a precursor for forming a thin film of the present invention is characterized by comprising a step of synthesizing a coordination compound represented by the following chemical formula 1 by reacting a compound represented by the following chemical formula 2 with an alkyl cyanide having an alkyl carbon number of 1 to 15, or a linear or cyclic saturated hydrocarbon having a carbon number of 3 to 15 and substituted with one or more of nitrogen (N), oxygen (O), phosphorus (P) or sulfur (S) in an organic solvent. In this case, since the precursor is in a liquid state at room temperature and has high volatility, it has an extremely fast deposition rate, is easy to handle when injected into a thin film deposition chamber, and is particularly advantageous in that it produces a precursor for forming a thin film that has excellent thermal stability, high purity, and excellent step coverage.

[0043] [Chemical formula 1] MXnLmYz

[0044] (M is niobium (Nb), tungsten (W) or molybdenum (Mo), X is a halogen element, n is an integer of 1 to 6, L is an alkyl cyanide having an alkyl carbon number of 1 to 15 or a linear or cyclic saturated hydrocarbon having a carbon number of 3 to 15 and substituted with one or more nitrogen (N), oxygen (O), phosphorus (P) or sulfur (S), m is an integer of 1 to 3, the bonded Y is an amine, z is an integer of 0 to 4, and n+z is an integer of 3 to 6.)

[0045] [Chemical formula 2] MX a Y (6-a)

[0046] (M is niobium (Nb), tungsten (W) or molybdenum (Mo), X is a halogen element, Y is an amine, and a is an integer of 1 to 6.)

[0047] The above-mentioned contents of the thin film-forming precursor of the present invention are similarly applied to the manufacturing method thereof, so that the repeated description will be omitted here.

[0048] The organic solvent may be preferably a halogenated hydrocarbon, more preferably an alkyl halide having an alkyl group having 1 to 5 carbon atoms, and even more preferably a methyl halide. In this case, there is an effect that the synthesis of the thin film-forming precursor can be stably carried out.

[0049] The alkyl cyanide or the saturated hydrocarbon may be contained in an amount of preferably 20 to 40% by weight, more preferably 25 to 40% by weight, and even more preferably 25 to 33% by weight, relative to 100% by weight of the total of the compound represented by the chemical formula 2 and the alkyl cyanide or the saturated hydrocarbon. Within this range, there is an advantage that the thin film-forming precursor can be easily liquefied.

[0050] As another example, the alkyl cyanide or the saturated hydrocarbon may be contained in an amount of 1 to 1.5 equivalents (eq.) based on the compound represented by Chemical Formula 2, more preferably 1.0 to 1.2 equivalents (eq.), and more preferably 1.0 to 1.1 equivalents (eq.). Within this range, there is an advantage that the thin film-forming precursor can be easily liquefied.

[0051] The synthesis is preferably carried out at 15 to 25°C, more preferably at 20 to 25°C, and even more preferably at 20 to 23°C. Within this range, the synthesis of the thin film-forming precursor can be stably carried out.

[0052] The synthesis can be, for example, 30 minutes or more, preferably 1 hour or more, and, for another example, 10 hours or less, preferably 5 hours or less, more preferably 2 hours or less. Within this range, the synthesis of the thin film-forming precursor can be stably carried out.

[0053] The method for preparing the precursor for forming a thin film may preferably include the steps of filtering the synthesized solution; and evaporating the filtrate obtained after the filtration under reduced pressure to obtain the coordination compound represented by Chemical Formula 1. In this case, there is an advantage that the precursor for forming a thin film can be easily liquefied.

[0054] The reduced pressure evaporation can be carried out preferably at 80 to 150°C and 0.1 to 100 torr, more preferably at 100 to 150°C and 0.5 to 10 torr, and even more preferably at 110 to 130°C and 0.5 to 5 torr. Within these ranges, there is an advantage that the thin film-forming precursor can be easily liquefied.

[0055] The method for producing the thin film precursor may preferably further include a step of mixing and diluting the obtained coordination compound with an alkyl cyanide having an alkyl carbon number of 1 to 15. In such a case, there is an advantage that the thin film precursor can be easily liquefied.

[0056] The method for producing a thin film according to the present invention includes the steps of injecting a precursor for forming a thin film according to the present invention into a CVD chamber or an ALD chamber and adsorbing it onto the surface of a loaded substrate; purging remaining unadsorbed precursor for forming a thin film with a purge gas; supplying a reaction gas to react with the precursor for forming a thin film adsorbed onto the surface of the substrate to form a metal thin film layer; and purging reaction by-products with a purge gas. In this case, the deposition rate of the precursor for forming a thin film is very fast, it is easy to handle, and a thin film with excellent step coverage can be produced.

[0057] As a specific example, the method for producing the present thin film can follow the order of steps shown in FIG. 1 below, but is not limited thereto.

[0058] For example, the thin film precursor may be mixed with a non-polar solvent to adjust the viscosity or vapor pressure, and then introduced into the chamber.

[0059] The substrate may preferably be a dielectric film, which has the advantage that the capacitance (Cs) of the finally manufactured capacitor is excellent.

[0060] The dielectric film may be formed of a high dielectric constant material, for example, HfO. 2、 Al 2 O 3 , TiO 2 , ZrO 2 , Ta 2 O 5 or Y 2 O 3 and more preferably HfO 2 is formed.

[0061] The non-polar solvent may be at least one selected from the group consisting of alkanes and cycloalkanes. In this case, there is an advantage that the step coverage is improved even when the deposition temperature during thin film formation is increased, while containing an organic solvent that has low reactivity and solubility and is easy to control moisture.

[0062] As a more preferred example, the non-polar solvent may include a C1 to C10 alkane or a C3 to C10 cycloalkane, and is preferably a C3 to C10 cycloalkane, which has the advantages of low reactivity and solubility and easy moisture management.

[0063] In this description, C1, C3 etc. refer to carbon numbers.

[0064] The cycloalkane may be preferably a C3 to C10 monocycloalkane. Among the monocycloalkanes, cyclopentane is preferred in the vapor deposition process because it is liquid at room temperature and has the highest vapor pressure, but is not limited thereto.

[0065] The non-polar solvent has, for example, a solubility in water (25° C.) of 200 mg / L or less, preferably 50 to 200 mg / L, and more preferably 135 to 175 mg / L. Within this range, the non-polar solvent has the advantages of low reactivity with thin film-forming precursors and easy moisture control.

[0066] The solubility in this description is not particularly limited and may be determined by a measurement method or standard commonly used in the technical field to which the present invention pertains. As an example, a saturated solution can be measured by HPLC.

[0067] The non-polar solvent may preferably comprise 5 to 95% by weight, more preferably 10 to 90% by weight, even more preferably 40 to 90% by weight, and most preferably 70 to 90% by weight, based on the total weight of the thin film-forming precursor and the non-polar solvent.

[0068] If the content of the non-polar solvent exceeds the upper limit, impurities are induced, and the resistance and the number of impurities in the thin film increase. If the content of the organic solvent is less than the lower limit, there is a drawback that the effect of improving step coverage by adding the solvent and the effect of reducing impurities such as chlorine (Cl) ions are small.

[0069] In the thin film manufacturing method, for example, the decrease rate of the thin film growth rate (Å / cycle) per cycle calculated by Equation 1 is −5% or less, preferably −10% or less, more preferably −20% or less, more preferably −30% or less, even more preferably −40% or less, and most preferably −45% or less. Within this range, the method has excellent step coverage and film thickness uniformity.

[0070] [Formula 1] Decrease rate of thin film growth rate per cycle (%) = [(thin film growth rate per cycle when thin film growth inhibitor is used - thin film growth rate per cycle when thin film growth inhibitor is not used) / thin film growth rate per cycle when thin film growth inhibitor is not used] x 100

[0071] In the thin film manufacturing method, the residual halogen intensity (c / s) in the thin film formed after 200 cycles, as measured based on SIMS, can be preferably 10,000 or less, more preferably 8,000 or less, even more preferably 7,000 or less, and even more preferably 6,000 or less. Within such a range, the method is excellent in preventing corrosion and deterioration.

[0072] The purging rate in this description is preferably 1,000 to 10,000 sccm, more preferably 2,000 to 7,000 sccm, and even more preferably 2,500 to 6,000 sccm. Within this range, the thin film growth rate per cycle is reduced to a preferred range, and process by-products are reduced.

[0073] The ALD (atomic layer deposition) process is very advantageous in the manufacture of integrated circuits (ICs) that require a high aspect ratio, and has advantages such as excellent conformality, uniformity, and precise thickness control due to its self-limiting thin film growth mechanism.

[0074] The method for producing the thin film may be performed at a deposition temperature in the range of, for example, 50 to 900°C, preferably 300 to 700°C, more preferably 350 to 600°C, more preferably 400 to 550°C, and still more preferably 400 to 500°C. By embodying the characteristics of the ALD process within this range, it is highly effective in growing a thin film with excellent film quality.

[0075] The method for producing the thin film can be carried out, for example, at a deposition pressure in the range of 0.1 to 10 Torr, preferably at a deposition pressure in the range of 0.5 to 5 Torr, and most preferably at a deposition pressure in the range of 1 to 3 Torr. Within this range, it is effective to obtain a thin film of uniform thickness.

[0076] In this description, deposition temperature and deposition pressure may be measured as the temperature and pressure formed within a deposition chamber or as the temperature and pressure applied to a substrate within the deposition chamber.

[0077] The thin film manufacturing method may preferably include a step of raising the temperature in the chamber to a deposition temperature before introducing the thin film precursor into the chamber; and / or a step of injecting an inert gas into the chamber to purge the chamber before introducing the thin film precursor into the chamber.

[0078] As a specific example, the method for producing the thin film will be described below.

[0079] First, a substrate on which a thin film is to be formed is placed in a deposition chamber capable of atomic layer deposition.

[0080] The substrate may include a semiconductor substrate such as a silicon substrate, silicon oxide substrate, or the like.

[0081] The substrate may further have a conductive or insulating layer formed thereon.

[0082] The thin film precursor, or a mixture thereof with a non-polar solvent, is provided for depositing a thin film on a substrate disposed in the deposition chamber.

[0083] Then, the prepared thin film forming precursor or a mixture of the precursor and a non-polar solvent is injected into a vaporizer, converted into a vapor phase, and delivered to a deposition chamber to be adsorbed onto a substrate, and the unadsorbed thin film forming composition is purged.

[0084] In this description, the method of delivering a precursor for forming a thin film to a deposition chamber can be, for example, a method of transferring a vaporized gas using a mass flow controller (MFC) (Vapor Flow Control; VFC), or a method of transferring a liquid using a liquid mass flow controller (LMFC) (Liquid Delivery System; LDS), with the LDS method being preferred.

[0085] Here, argon (Ar), nitrogen (N 2 ), helium (He), or a mixture of two or more gases may be used, but is not limited thereto.

[0086] As the purge gas in this description, for example, an inert gas can be used, and preferably the above-mentioned transport gas or dilution gas can be used.

[0087] Next, a reaction gas is supplied. The reaction gas is not particularly limited as long as it is a reaction gas commonly used in the technical field to which the present invention pertains, and preferably includes a reducing agent, a nitriding agent, or an oxidizing agent. The reducing agent reacts with the thin film forming precursor adsorbed on the substrate to form a metal thin film, the nitriding agent forms a metal nitride thin film, and the oxidizing agent forms a metal oxide thin film.

[0088] Preferably, the reducing agent is ammonia gas (NH 3 ) or hydrogen gas (H 2 ), and the nitriding agent may be nitrogen gas (N 2 ) wherein the oxidizing agent is H 2 O, H 2 O 2 , O 2 , O3 and N 2 O.

[0089] Next, the remaining unreacted reactant gas is purged with an inert gas, which removes not only the excess reactant gas but also the by-products that are produced.

[0090] As described above, the steps of adsorbing the thin film precursor onto the substrate, purging unadsorbed thin film composition, supplying a reactive gas, and purging residual reactive gas constitute a unit cycle, and the unit cycle can be repeated to form a thin film of a desired thickness.

[0091] The unit cycle may be, for example, 100 to 1000 times, preferably 100 to 500 times, and more preferably 150 to 300 times. Within this range, the desired thin film properties are effectively exhibited.

[0092] The semiconductor substrate of the present invention is characterized by being manufactured by the thin film manufacturing method described herein, and has the advantages of being prevented from corrosion and deterioration in such a case, and having excellent step coverage and uniformity of the thin film thickness.

[0093] The semiconductor substrate may preferably be a thin film capacitor or a semiconductor element capacitor.

[0094] The thin film thus produced preferably has a thickness of 20 nm or less, a resistivity of 0.1 to 400 μΩ cm, a halogen content of 10,000 ppm or less, and a step coverage rate of 90% or more. Within these ranges, the thin film has excellent performance as a diffusion barrier film and has an effect of reducing corrosion of metal wiring materials, but is not limited thereto.

[0095] The thin film may have a thickness of, for example, 5 to 20 nm, preferably 10 to 20 nm, more preferably 15 to 18.5 nm, and even more preferably 17 to 18.5 nm. Within this range, the thin film has excellent thin film properties.

[0096] The thin film may have a resistivity of, for example, 0.1 to 400 μΩ·cm, preferably 50 to 400 μΩ·cm, more preferably 200 to 400 μΩ·cm, even more preferably 300 to 400 μΩ·cm, still more preferably 330 to 380 μΩ·cm, and most preferably 340 to 370 μΩ·cm. Within this range, the thin film has the effect of having excellent thin film properties.

[0097] The halogen content of the thin film is more preferably 9,000 ppm or less or 1 to 9,000 ppm, even more preferably 8,500 ppm or less or 100 to 8,500 ppm, and even more preferably 8,200 ppm or less or 1,000 to 8,200 ppm. Within this range, there is an effect of reducing corrosion of the metal wiring material while maintaining excellent thin film properties.

[0098] As an example, the thin film has a step coverage of 80% or more, preferably 90% or more, and more preferably 93% or more. Within this range, even thin films with complex structures can be easily deposited on a substrate, and this has the advantage that the thin films can be applied to next-generation semiconductor devices.

[0099] The thin film may be, for example, a NbN thin film or a NbO 2 It can be a thin film, preferably NbN.

[0100] In the following, preferred embodiments and drawings are presented to aid in understanding the present invention. However, the following embodiments and drawings are merely illustrative of the present invention, and it will be apparent to those skilled in the art that various changes and modifications are possible within the scope and technical spirit of the present invention. Naturally, such changes and modifications also fall within the scope of the appended claims.

[0101] [Example] <Synthesis of precursors for thin film formation> [Example 1] (Production of niobium coordination compound with 2-methylbutyronitrile) In a 3L flask, 137g (0.73mol, 1eq) of niobium fluoride (V) was weighed in a glove box. The starting material was diluted with 0.5M (1.5L) of dichloromethane, a solvent. 74mL (0.73mol, 1eq) of 2-methylbutylronitrile, a ligand to be coordinated, was added thereto, stirred at room temperature for 1 hour, and then filtered. The filtrate was subjected to reduced pressure distillation to remove the solvent, and then to a purification process (70℃@1.0Torr), to obtain the precursor to be obtained in a colorless liquid state (158g) with a yield of 80%.

[0102] [Example 2] (Production of niobium coordination compound with 2,2-dimethylvaleronitrile) In a 3L flask in a glove box, 126g (0.67mol, 1eq) of niobium fluoride (V) was weighed as a starting material. The starting material was diluted to 0.5M (1.4L) with dichloromethane as a solvent. 92mL (0.67mol, 1eq) of the ligand to be coordinated (2,2-dimethylvaleronitrile) was then poured into the flask, stirred at room temperature for 1 hour, and filtered. The filtrate was distilled under reduced pressure to remove the solvent, and then purified (70℃@1.0Torr) to obtain the desired precursor in the form of a colorless liquid (160g) with a yield of 80%.

[0103] [Experimental Example] The thin film-forming precursors produced in Examples 1 and 2 were subjected to DSC analysis, TGA analysis, and NMR analysis in a dry state, and the results are shown in the following FIGS. 2 to 8.

[0104] FIG. 2 shows the thin film precursor prepared in Example 1 before and after drying. It was confirmed that the thin film precursor was still in a liquid state after drying (dry), just like before drying (solution), even when it did not contain any alkyl cyanide solvent.

[0105] FIG. 3 below is a graph obtained by DSC analysis of the precursor for forming a thin film prepared in Example 1. It can be easily predicted that the precursor has an exotermic temperature of 150° C., is liquid at room temperature, has high volatility, has a very fast deposition rate, is easy to handle when injected into a thin film deposition chamber, and can produce a thin film having excellent thermal stability, high purity, and excellent step coverage.

[0106] The following Figure 4 is a graph obtained by TGA analysis of the precursor for forming a thin film prepared in Example 1. It was confirmed that the final temperature (To) was 200°C, the residue was less than 3 wt%, and the purity was excellent while the thermal stability was high. The characteristic points are as follows. If the thermal stability of the precursor for forming a thin film prepared in Example 1 had decreased and the coordinated ligand had been separated from the niobium metal, two patterns (2-pattern) would have been obtained, but in the precursor for forming a thin film according to the present invention prepared in Example 1, a step-like graph of one pattern (1-pattern) was obtained, which confirmed that no thermal decomposition occurred at all.

[0107] FIG. 5 below shows the NMR spectrum of the thin film precursor prepared in Example 1. From this result, it was confirmed that the desired niobium coordination compound coordinated with 2-methylbutyronitrile was prepared.

[0108] FIG. 6 below is a graph obtained by DSC analysis of the precursor for forming a thin film produced in Example 2. It can be easily predicted that the precursor has an exothermic temperature of 150° C., is liquid at room temperature, has high volatility, has a very fast deposition rate, is easy to handle when injected into a thin film deposition chamber, and is capable of producing a thin film with excellent thermal stability, high purity, and excellent step coverage.

[0109] FIG. 7 below is a graph obtained by TGA analysis of the precursor for forming a thin film prepared in Example 2. It can be seen that the final temperature (To) is 200° C., the residue is less than 3 wt %, and the precursor has high thermal stability and excellent purity, making it suitable for producing high-quality thin films.

[0110] FIG. 8 below shows the NMR spectrum of the thin film precursor produced in Example 2. From this result, it was confirmed that the desired niobium coordination compound coordinated with 2,2-dimethylvaleronitrile was produced.

[0111] In conclusion, it has been confirmed that the thin film-forming precursor according to the present invention is in a liquid state at room temperature, has high volatility, has a very fast deposition rate, is easy to handle when injected into a thin film deposition chamber, and is capable of producing thin films that are particularly excellent in thermal stability, purity, and step coverage.

Claims

1. 20 to 100% by weight of a coordination compound formed from a halide of a metal selected from niobium (Nb), tungsten (W) and molybdenum (Mo) and an alkyl cyanide having an alkyl carbon number of 1 to 15; 0 to 80% by weight of alkyl cyanide having 1 to 15 alkyl carbon atoms; Including, A precursor for forming a thin film, characterized in that it is liquid under conditions of 20° C. and 1 bar.

2. The halide is a fluorine compound. The thin film forming precursor according to claim 1 .

3. The metal is pentavalent. The thin film forming precursor according to claim 1 .

4. The precursor for forming a thin film is characterized in that the final temperature (Tf) measured by a thermogravimetric analyzer (TGA) is 180° C. or higher; The thin film forming precursor according to claim 1 .

5. The precursor for forming a thin film is characterized in that the residue by thermogravimetric analyzer (TGA) is less than 3 wt. %. The thin film forming precursor according to claim 1 .

6. The precursor for forming a thin film is characterized in that the exothermic temperature measured by a differential scanning calorimeter (DSC) is 150° C. or higher. The thin film forming precursor according to claim 1 .

7. The method comprises the step of reacting a metal halide selected from niobium (Nb), tungsten (W) and molybdenum (Mo) with an alkyl cyanide having an alkyl carbon number of 1 to 15 in an organic solvent to synthesize a coordination compound. A method for producing a precursor for forming a thin film.

8. The organic solvent is a halogenated hydrocarbon. A method for producing the thin film precursor according to claim 7.

9. The alkyl cyanide or saturated hydrocarbon is contained in an amount of 20 to 40% by weight based on 100% by weight of the total of the halide and the alkyl cyanide or saturated hydrocarbon. A method for producing the thin film precursor according to claim 7.

10. The synthesis is carried out at 15 to 25° C. A method for producing the thin film precursor according to claim 7.

11. filtering the synthesized solution; and evaporating the filtrate obtained after the filtration under reduced pressure to obtain the coordination compound. A method for producing the thin film precursor according to claim 7.

12. The method further comprises the step of mixing and diluting the obtained coordination compound with an alkyl cyanide having an alkyl carbon number of 1 to 15, A method for producing the thin film precursor according to claim 11.

13. Injecting the precursor for forming a thin film according to any one of claims 1 to 6 into a CVD chamber or an ALD chamber and allowing it to be adsorbed on a surface of a loaded substrate; purging any remaining unadsorbed thin film precursor with a purge gas; supplying a reactive gas to react with the precursor for forming a thin film adsorbed on the surface of the substrate to form a thin metal film layer; and purging the reaction by-products with a purge gas. Methods for producing thin films.

14. The reactive gas is a reducing agent, a nitriding agent or an oxidizing agent. The method for producing a thin film according to claim 13.

15. The precursor for forming the thin film is transferred to the substrate surface by a VFC method, a DLI method or an LDS method. The method for producing a thin film according to claim 13.

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