Bismuth precursor compound, method for preparing same, and method for forming bismuth-containing film using same

Abstract

The present invention relates to a bismuth precursor compound, a composition thereof, and a method for forming a bismuth-containing film using same. The bismuth precursor compound exists in a liquid state at room temperature and has excellent volatility and thermal stability, thereby being able to form a bismuth-containing film which is uniform and has excellent quality by an atomic layer deposition method. In particular, the compound can be used as a liquid bismuth precursor compound capable of in-situ processing in which a film can be formed under the same process temperature conditions as high-k materials.

Description

Bismuth precursor compound, method for preparing the same, and method for forming a bismuth-containing film using the same

[0001] The present invention relates to a bismuth precursor compound, a method for producing the same, a precursor composition for forming a bismuth film comprising the same, a bismuth-containing film using the same, and a method for forming the same.

[0002] Bismuth oxide has a specific gravity of 8.5 to 9.25 and a melting point of 825℃, and is used in various fields such as electronic devices such as optical glass varistors and as a substitute for lead oxide.

[0003] Bismuth-based oxide thin films are used as dielectric, ferroelectric, electro-optical, photoelectric, oxygen ion conducting, and superconducting materials. Furthermore, controlling leakage current, which plays a crucial role in electrical properties in both memory and non-memory fields, has become a major goal, and bismuth oxide is expected to exhibit excellent leakage current suppression effects at the interface of high-k dielectric films.

[0004] Currently, DRAM, Flash Memory, ReRAM, PCRAM in the memory field and Logic Memory in the non-memory field are reaching the physical limits of the two-dimensional structure. To overcome these limitations, products with high aspect ratios, excellent step coverage, and three-dimensional structures are being manufactured, and bismuth-containing oxide thin films suitable for these are required. Accordingly, there is a demand for bismuth-containing precursors that are suitable for the process temperatures of various applications. Also, there is a demand for bismuth-containing precursors that can be used in atomic layer deposition (ALD) that have excellent thermal stability and can secure a wide process window to overcome the step coverage caused by high aspect ratios. Forming bismuth-containing oxide thin films using ALD is expected to improve the thickness uniformity and physical properties of the thin films, and enhance the characteristics of semiconductor devices over a wide range of process temperatures.

[0005] There is a need for the development of a liquid bismuth compound that is thermally stable, highly volatile, and capable of forming pure bismuth oxide thin films even at low temperatures, as well as a bismuth precursor for ALD that can be applied in processes such as the in-situ process, a newly developed process that can form not only a single bismuth film but also multiple films in combination.

[0006] [Prior Art Literature]

[0007] [Patent Document]

[0008] (Patent Document 1) U.S. Patent No. 7,618,681

[0009] The present invention was devised to solve the problems of the above-mentioned prior art, and the technical problem to be solved by the present invention is to provide a bismuth precursor compound having a single structure, existing in a liquid state at room temperature, and having excellent thermal stability, so that a uniform and high-quality bismuth-containing film can be formed by atomic layer deposition (ALD), and further, to provide a method for manufacturing the bismuth precursor compound in a safe and efficient manner. In addition, the present invention provides a method for forming a bismuth-containing film by depositing the bismuth-containing film using the bismuth precursor compound.

[0010] However, the problems to be solved by the present invention are not limited to the problems mentioned above, and other problems not mentioned will be clearly understood by those skilled in the art from the description below.

[0011] To achieve the above object, the present invention provides a bismuth precursor compound represented by the following chemical formula 1:

[0012] [Chemical Formula 1]

[0013]

[0014] In the above chemical formula 1,

[0015] X is And,

[0016] m is an integer from 1 to 3,

[0017] R1 is a hydrogen atom, a linear or branched C1-C4 alkyl group, -NR 10 R 11 and -OR 12 is selected as a group consisting of,

[0018] R2 to R 12 are each independently selected from the group consisting of a hydrogen atom and a linear or branched C1-C4 alkyl group,

[0019] R a and R bare each independently selected from the group consisting of a hydrogen atom and a linear or branched C1-C4 alkyl group, or R a and R b are linked to each other to form a 4-8 membered heterocycle with the N atom to which they are bonded,

[0020] R c is selected from the group consisting of hydrogen atoms and linear or branched C1-C4 alkyl groups,

[0021] n is an integer from 0 to 2.

[0022] The present invention also provides a composition for forming a bismuth-containing film, which comprises a bismuth precursor compound represented by the above chemical formula 1 and is used for depositing a bismuth-containing film.

[0023] The present invention also provides a method for forming a bismuth-containing film, comprising the step of depositing a bismuth-containing film using a composition for forming a bismuth-containing film comprising a bismuth precursor compound represented by the above chemical formula 1.

[0024] The present invention also provides a bismuth-containing film formed using a composition for forming a bismuth-containing film comprising a bismuth precursor compound represented by the above chemical formula 1.

[0025] The bismuth precursor compound represented by Chemical Formula 1 of the present invention exists in a liquid state at room temperature, and has excellent volatility and thermal stability, enabling the formation of a uniform and high-quality bismuth-containing film by atomic layer deposition (ALD). In particular, it can be used as a liquid bismuth precursor compound capable of an in-situ process that can form a film under the same process temperature conditions as a high-k material.

[0026]

[0027] Figure 1 is a diagram of a bismuth precursor compound manufactured in Example 2 of the present invention. 1This is a graph showing the results of H-NMR analysis.

[0028] Figure 2 is a graph showing the results of thermal gravimetry analysis (TGA) of bismuth precursor compounds manufactured in Examples 1 and 2 of the present invention.

[0029] FIG. 3 is a graph showing the results of thermal decomposition evaluation performed on TiN and Si substrates using a bismuth precursor compound manufactured in Example 1 of the present invention, without reactants, in an ALD process.

[0030] FIG. 4 is a graph showing the results of a thermal decomposition evaluation performed on TiN and Si substrates using a bismuth precursor compound manufactured in Comparative Example 1 of the present invention, without reactants, in an ALD process.

[0031] FIG. 5 is a transmission electron microscope (TEM) image of a bismuth-containing oxide film formed on a TiN substrate through an ALD process at a process temperature of 300° C. using a bismuth precursor manufactured in Example 1 of the present invention.

[0032] FIG. 6 is a schematic diagram of a reference MIM capacitor (Metal-insulator-metal Capacitor) in which the dielectric layer is composed of a single layer of a zirconium-containing oxide film, in order to compare and evaluate the electrical characteristics according to the introduction of a bismuth-containing oxide film in the dielectric layer in Experimental Example 4 of the present invention.

[0033] Figure 7 is a schematic diagram of a MIM capacitor manufactured to evaluate electrical characteristics by introducing a bismuth-containing oxide film between the upper electrode and the zirconium-containing oxide film in Experimental Example 4 of the present invention.

[0034] Figure 8 is a schematic diagram of a MIM capacitor manufactured to evaluate electrical characteristics by introducing a bismuth-containing oxide film between a lower electrode and a zirconium-containing oxide film in Experimental Example 4 of the present invention.

[0035] FIG. 9 is a graph showing the change in dielectric constant according to the number of deposition cycles (0 to 60 cycles) of a bismuth-containing oxide film formed on a dielectric layer of a MIM capacitor using a bismuth precursor manufactured in Example 1 of the present invention.

[0036] FIG. 10 is a graph showing the change in leakage current according to the number of deposition cycles (0 to 60 cycles) of a bismuth-containing oxide film formed on a dielectric layer of a MIM capacitor using a bismuth precursor manufactured in Example 1 of the present invention.

[0037] FIG. 11 is a graph showing the change in dielectric constant according to the number of bismuth-containing oxide film deposition cycles (0 to 60 cycles) in the dielectric layer of an MIM capacitor that was subjected to post-deposition annealing (PDA) at 500°C for 30 seconds using a bismuth precursor manufactured in Example 1 of the present invention.

[0038] FIG. 12 is a graph showing the change in leakage current according to the number of bismuth-containing oxide film deposition cycles (0 to 60 cycles) in the dielectric layer of a MIM capacitor that was subjected to post-deposition annealing (PDA) at 500°C for 30 seconds using a bismuth precursor manufactured in Example 1 of the present invention.

[0039]

[0040] The advantages and features of the present invention, and methods for achieving them, will become clearer with reference to the embodiments described below. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms. These embodiments are provided solely to ensure complete disclosure of the present invention and to fully inform those skilled in the art of the scope of the invention. The present invention is defined solely by the scope of the claims.

[0041] Additionally, when it is said in this specification that a part is "on" another part, this includes not only cases where it is "directly on" the other part, but also cases where there is another part in between.

[0042] In this specification, when a part is said to "include" a certain component, this does not mean that it excludes other components, but rather that it may include other components, unless otherwise specifically stated.

[0043] All numbers and expressions indicating the amounts of components, reaction conditions, etc. described in this specification should be understood to be modified by the term “about” in all cases unless otherwise specified.

[0044] In this specification, the terms “film” or “thin film” each mean both “film” and “thin film” unless specifically distinguished.

[0045] As used herein, the term "alkyl" or "alkyl group" includes linear or branched alkyl groups and all possible isomers thereof. For example, the alkyl group may include a methyl group (Me), an ethyl group (Et), an n-propyl group ( n Pr), iso-profiler ( i Pr), n-butyl group ( n Bu), tert-butyl group( t Bu), iso-butyl group( i Bu), sec-butyl group( s Bu), pentyl group, hexyl group, isohexyl group, heptyl group, 4,4-dimethylpentyl group, octyl group, 2,2,4-trimethylpentyl group, nonyl group, decyl group, and isomers thereof, but may not be limited thereto.

[0046]

[0047] [Bismuth precursor compound]

[0048] To achieve the above object, the present invention provides a bismuth precursor compound represented by the following chemical formula 1:

[0049] [Chemical Formula 1]

[0050]

[0051] In the above chemical formula 1,

[0052] X is And,

[0053] m is an integer from 1 to 3,

[0054] R1 is a hydrogen atom, and a linear or branched C1-C4 alkyl group, -NR a R b or -OR c is selected as a group consisting of,

[0055] R2 to R 12 are each independently selected from the group consisting of a hydrogen atom and a linear or branched C1-C4 alkyl group,

[0056] R a and R b are each independently selected from the group consisting of a hydrogen atom and a linear or branched C1-C4 alkyl group, or R a and R b are linked to each other to form a 4-8 membered heterocycle with the N atom to which they are bonded,

[0057] R c is selected from the group consisting of hydrogen atoms and linear or branched C1-C4 alkyl groups,

[0058] n is an integer from 0 to 2.

[0059] In one embodiment of the present invention, in the chemical formula 1, R1 may be, but is not limited to, a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an iso-butyl group, a sec-butyl group, or a tert-butyl group.

[0060] In one embodiment of the present invention, in the chemical formula 1, R2 to R 12 , and R a Inland R cmay each independently be, but is not limited to, a hydrogen atom, a methyl group, an ethyl group, an n-propyl group, an iso-propyl group, an iso-butyl group, a sec-butyl group, or a tert-butyl group.

[0061] In one embodiment of the present invention, in the chemical formula 1, -NR a R b is R a and R b may be linked to each other to form a pyrrolidine group, a piperidine group, a pyrrole group, a 2,6-dimethylpiperidine group, a 4-methylpiperazine group, or a morpholine group with the N atom to which they are bonded, but are not limited thereto.

[0062] Specifically, the bismuth precursor compound may be a compound represented by one of the following chemical formulas:

[0063]

[0064]

[0065]

[0066]

[0067] The above bismuth precursor compound exists in a liquid state at room temperature and has excellent volatility, so that a bismuth-containing film can be easily formed by chemical vapor deposition (CVD) as well as atomic layer deposition (ALD).

[0068]

[0069] [Method for producing a bismuth precursor compound]

[0070] A compound represented by the chemical formula 1 can be obtained by reacting a compound represented by the chemical formula A of the following reaction scheme 1 with a compound represented by the chemical formula B below. In addition, after the reaction is completed, a step of removing a salt produced during the reaction through a filtration process or the like, and distilling a solvent and volatile by-products under reduced pressure can be further included.

[0071] In one embodiment of the present invention, the method for preparing the bismuth precursor compound may be performed in a nonpolar solvent such as pentane or hexane, or a polar solvent such as tetrahydrofuran, diethyl ether, or dichloromethane, but is not limited thereto.

[0072] In one embodiment of the present invention, the method for producing the bismuth precursor compound may be performed in an inert gas atmosphere such as nitrogen or argon to suppress reaction with moisture or oxygen, but is not limited thereto.

[0073] [Reaction Formula 1]

[0074]

[0075] In the above reaction formula 1,

[0076] X is And,

[0077] m is an integer from 1 to 3,

[0078] M is selected from Li, Na, K and MgCl,

[0079] R1 is a hydrogen atom, and a linear or branched C1-C4 alkyl group, -NR 10 R 11 and -OR 12 is selected as a group consisting of,

[0080] R2 to R 12 are each independently selected from the group consisting of a hydrogen atom and a linear or branched C1-C4 alkyl group,

[0081] R a and Rb are each independently selected from the group consisting of a hydrogen atom and a linear or branched C1-C4 alkyl group, or R a and R b are linked to each other to form a 4-8 membered heterocycle with the N atom to which they are bonded,

[0082] R c is selected from the group consisting of hydrogen atoms and linear or branched C1-C4 alkyl groups,

[0083] n is an integer from 0 to 2.

[0084]

[0085] [Precursor composition for forming a bismuth-containing film]

[0086] According to one embodiment of the present invention, a composition for forming a bismuth-containing film is provided, comprising a bismuth precursor compound represented by the above chemical formula 1.

[0087] In one embodiment of the present invention, the bismuth precursor compound may include at least one selected from the group consisting of compounds represented by the chemical formulae 1-1 to 1-70.

[0088] In one embodiment of the present invention, the bismuth-containing film may include at least one selected from the group consisting of a bismuth-containing metal film, a bismuth-containing oxide film, a bismuth-containing carbide film, a bismuth-containing sulfide film, and a bismuth-containing nitride film, but may not be limited thereto.

[0089] In one embodiment of the present invention, the bismuth-containing film may be deposited by chemical vapor deposition (CVD) or atomic layer deposition (ALD) using the precursor composition for forming the bismuth-containing film, but may not be limited thereto.

[0090] In one embodiment of the present invention, the bismuth-containing film forming precursor composition may be used to form a bismuth-containing film at a temperature range of room temperature to about 500°C, but may not be limited thereto.

[0091] In one embodiment of the present invention, the precursor composition for forming a bismuth-containing film can be used to deposit a bismuth-containing film having a thickness ranging from about 0.1 nm to about 500 nm, but may be applied in various ways depending on the intended use and may not be limited thereto.

[0092]

[0093] [Bismuth-containing film and method for forming the same]

[0094] According to one embodiment of the present invention, a bismuth-containing film is provided, formed using a composition for forming a bismuth-containing film, which comprises a bismuth precursor compound represented by the above chemical formula 1.

[0095] In one embodiment of the present invention, the bismuth precursor compound may include at least one selected from the group consisting of compounds represented by the chemical formulae 1-1 to 1-70.

[0096] According to one embodiment of the present invention, a method for forming a bismuth-containing film can be provided, including a step of depositing a bismuth-containing film using a composition for forming a bismuth-containing film including a bismuth precursor compound represented by the above chemical formula 1.

[0097] In one embodiment of the present invention, the bismuth-containing film may include at least one selected from the group consisting of a bismuth-containing metal film, a bismuth-containing oxide film, a bismuth-containing carbide film, a bismuth-containing sulfide film, and a bismuth-containing nitride film, but may not be limited thereto.

[0098] In one embodiment of the present invention, the bismuth-containing film may be deposited by chemical vapor deposition (CVD) or atomic layer deposition (ALD), but may not be limited thereto.

[0099] In one embodiment of the present invention, chemical vapor deposition or atomic layer deposition may be performed using a deposition apparatus, deposition conditions, and one or more additional reactant gases known in the art, but may not be limited thereto.

[0100] In one embodiment of the present invention, the method for forming a bismuth-containing film includes, but is not limited to, supplying a bismuth-containing film forming composition including a bismuth precursor compound in a gaseous state to a substrate (substrate) located in a deposition chamber to form a bismuth-containing film on the surface of the substrate.

[0101] In one embodiment of the present invention, the bismuth-containing film may be formed at a temperature range of room temperature to about 500°C, but may not be limited thereto. For example, the bismuth-containing film may be formed at a temperature ranging from room temperature to about 500°C, from room temperature to about 450°C, from room temperature to about 400°C, from room temperature to about 350°C, from room temperature to about 300°C, from room temperature to about 250°C, from room temperature to about 200°C, from room temperature to about 150°C, from room temperature to about 100°C, from about 100°C to about 500°C, from about 100°C to about 450°C, from about 100°C to about 400°C, from about 100°C to about 350°C, from about 100°C to about 300°C, from about 100°C to about 250°C, from about 100°C to about 200°C, from about 100°C to about 150°C, from about 150°C to about 500°C, from about 150°C to about 450°C, about 150°C to about 400°C, about 150°C to about 350°C, about 150°C to about 300°C, about 150°C to about 250°C, about 150°C to about 200°C, about 200°C to about 500°C, about 200°C to about 450°C, about 200°C to about 400°C, about 200°C to about 350°C, about 200°C to about 300°C, about 200°C to about 250°C, about 250°C to about 500°C, about 250°C to about 450°C, about 250°C to about 400°C, about 250°C to about 350°C, about 250°C to about 300°C, about 300°C to about 500°C, about It may be formed at a temperature range of from about 300°C to about 450°C, from about 300°C to about 400°C, from about 300°C to about 350°C, from about 350°C to about 500°C, from about 350°C to about 450°C, from about 350°C to about 400°C, from about 400°C to about 500°C, from about 400°C to about 450°C, or from about 450°C to about 500°C, but may not be limited thereto.In one embodiment of the present invention, the bismuth-containing film may be formed at a temperature range of about 200°C to about 400°C, or about 300°C to about 400°C.

[0102] In one embodiment of the present invention, the bismuth-containing film may be formed in a thickness range of about 0.1 nm to about 500 nm, but may be applied in various ways depending on the application and may not be limited thereto. For example, the bismuth-containing film may have a thickness of about 0.1 nm to about 500 nm, about 0.1 nm to about 400 nm, about 0.1 nm to about 300 nm, about 0.1 nm to about 200 nm, about 0.1 nm to about 100 nm, about 0.1 nm to about 50 nm, about 0.1 nm to about 40 nm, about 0.1 nm to about 30 nm, about 0.1 nm to about 20 nm, about 0.1 nm to about 10 nm, about 1 nm to about 500 nm, about 1 nm to about 400 nm, about 1 nm to about 300 nm, about 1 nm to about 200 nm, about 1 nm to about 100 nm, about 1 nm to about 50 nm, about 1 nm to about 40 nm, about 1 nm to about 30 nm, about 1 nm to about 20 nm, about 1 nm to about 10 nm, about 10 nm to about 500 nm, about 10 nm to about 400 nm, about 10 nm to about 300 nm, about 10 nm to about 200 nm, about 10 nm to about 100 nm, about 10 nm to about 50 nm, about 10 nm to about 40 nm, about 10 nm to about 30 nm, about 10 nm to about 20 nm, about 20 nm to about 500 nm, about 20 nm to about 400 nm, about 20 nm to about 300 nm, about 20 nm to about 200 nm, about 20 nm to about 100 nm, about 20 nm to about 50 nm, about 20 nm to about 40 nm, about 20 nm to about 30 nm, about 30 nm to about 500 nm, about 30 nm to about 400 nm, about 30 nm to about 300 nm, about 30 nm to about 200 nm,About 30 nm to about 100 nm, about 30 nm to about 50 nm, about 30 nm to about 40 nm, about 40 nm to about 500 nm, about 40 nm to about 400 nm, about 40 nm to about 300 nm, about 40 nm to about 200 nm, about 40 nm to about 100 nm, about 40 nm to about 50 nm, about 50 nm to about 500 nm, about 50 nm to about 400 nm, about 50 nm to about 300 nm, about 50 nm to about 200 nm, about 50 nm to about 100 nm, about 100 nm to about 500 nm, about 100 nm to about 400 nm, about 100 nm to about 300 nm, about 100 nm to about 200 nm, about 200 nm to about It may be formed in a thickness range of about 500 nm, about 200 nm to about 400 nm, about 200 nm to about 300 nm, about 300 nm to about 500 nm, about 300 nm to about 400 nm, or about 400 nm to about 500 nm, but may not be limited thereto.

[0103] In one embodiment of the present invention, the bismuth-containing film may be formed on one or more substrates selected from, but not limited to, conventional silicon semiconductor wafers, compound semiconductor wafers, and plastic substrates (PI, PET, PES, and PEN). In addition, a substrate having holes or grooves may be used, and a porous substrate having a large surface area may be used, but not limited to. In addition, the bismuth-containing film may be formed on all or part of two or more different types of substrates in contact or connection simultaneously or sequentially, but not limited to.

[0104] In one embodiment of the present invention, the bismuth-containing film may be formed on a substrate including, but is not limited to, one or more unevennesses (grooves) having an aspect ratio of about 1 or more, for example, about 1 to about 100, and a width of about 1 μm or less, for example, about 10 nm to about 1 μm. The unevenness (grooves) may be in the form of holes or trenches.

[0105] For example, the aspect ratio is about 1 or more, about 10 or more, about 30 or more, about 50 or more, about 1 to about 100, about 1 to about 90, about 1 to about 80, about 1 to about 70, about 1 to about 60, about 1 to about 50, about 1 to about 40, about 1 to about 30, about 1 to about 20, about 1 to about 10, about 10 to about 100, about 10 to about 90, about 10 to about 80, about 10 to about 70, about 10 to about 60, about 10 to about 50, about 10 to about 40, about 10 to about 30, about 10 to about 20, about 20 to about 100, about 20 to about 90, about 20 to about 80, About 20 to about 70, about 20 to about 60, about 20 to about 50, about 20 to about 40, about 20 to about 30, about 30 to about 100, about 30 to about 90, about 30 to about 80, about 30 to about 70, about 30 to about 60, about 30 to about 50, about 30 to about 40, about 40 to about 100, about 40 to about 90, about 40 to about 80, about 40 to about 70, about 40 to about 60, about 40 to about 50, about 50 to about 100, about 50 to about 90, about 50 to about 80, about 50 to about 70, about 50 to about 60, about 60 to about 100, about It may be, but is not limited to, about 60 to about 90, about 60 to about 80, about 60 to about 70, about 70 to about 100, about 70 to about 90, about 70 to about 80, about 80 to about 100, about 80 to about 90, or about 90 to about 100.

[0106] Also, for example, the width is 1 ㎛ or less, about 10 nm to about 1 ㎛, about 10 nm to about 900 nm, about 10 nm to about 800 nm, about 10 nm to about 700 nm, about 10 nm to about 600 nm, about 10 nm to about 500 nm, about 10 nm to about 400 nm, about 10 nm to about 300 nm, about 10 nm to about 200 nm, about 10 nm to about 100 nm, about 10 nm to about 90 nm, about 10 nm to about 80 nm, about 10 nm to about 70 nm, about 10 nm to about 60 nm, about 10 to about 50 nm, about 10 nm to about 40 nm, about 10 nm to about 30 nm, about 10 nm to about 20 nm, about 20 nm About 1 ㎛, about 20 nm to about 900 nm, about 20 nm to about 800 nm, about 20 nm to about 700 nm, about 20 nm to about 600 nm, about 20 nm to about 500 nm, about 20 nm to about 400 nm, about 20 nm to about 300 nm, about 20 nm to about 200 nm, about 20 nm to about 100 nm, about 20 nm to about 90 nm, about 20 nm to about 80 nm, about 20 nm to about 70 nm, about 20 nm to about 60 nm, about 20 nm to about 50 nm, about 20 nm to about 40 nm, about 20 nm to about 30 nm, about 30 nm to about 1 ㎛, about 30 nm to about 900 nm, about 30 nm to about 800 nm, About 30 nm to about 700 nm, about 30 nm to about 600 nm, about 30 nm to about 500 nm, about 30 nm to about 400 nm, about 30 nm to about 300 nm, about 30 nm to about 200 nm, about 30 nm to about 100 nm, about 30 nm to about 90 nm, about 30 nm to about 80 nm,About 30 nm to about 70 nm, about 30 nm to about 60 nm, about 30 nm to about 50 nm, about 30 nm to about 40 nm, about 40 nm to about 1 μm, about 40 nm to about 900 nm, about 40 nm to about 800 nm, about 40 nm to about 700 nm, about 40 nm to about 600 nm, about 40 nm to about 500 nm, about 40 nm to about 400 nm, about 40 nm to about 300 nm, about 40 nm to about 200 nm, about 40 nm to about 100 nm, about 40 nm to about 90 nm, about 40 nm to about 80 nm, about 40 nm to about 70 nm, about 40 nm to about 60 nm, about 40 nm to about 50 nm, about 50 nm to about 1 ㎛, about 50 nm to about 900 nm, about 50 nm to about 800 nm, about 50 nm to about 700 nm, about 50 nm to about 600 nm, about 50 nm to about 500 nm, about 50 nm to about 400 nm, about 50 nm to about 300 nm, about 50 nm to about 200 nm, about 50 nm to about 100 nm, about 50 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 100 nm to about 1 ㎛, about 100 nm to about 900 nm, about 100 nm to about 800 nm, about 100 nm to about 700 nm, about 100 nm to about 600 nm, about 100 nm to About 500 nm, about 100 nm to about 400 nm, about 100 nm to about 300 nm, about 100 nm to about 200 nm, about 200 nm to about 1 ㎛, about 200 nm to about 900 nm, about 200 nm to about 800 nm, about 200 nm to about 700 nm, about 200 nm to about 600 nm, about 200 nm to about 500 nm,About 200 nm to about 400 nm, about 200 nm to about 300 nm, about 300 nm to about 1 μm, about 300 nm to about 900 nm, about 300 nm to about 800 nm, about 300 nm to about 700 nm, about 300 nm to about 600 nm, about 300 nm to about 500 nm, about 300 nm to about 400 nm, about 400 nm to about 1 μm, about 400 nm to about 900 nm, about 400 nm to about 800 nm, about 400 nm to about 700 nm, about 400 nm to about 600 nm, about 400 nm to about 500 nm, about 500 nm to about 1 μm, about 500 nm to about 900 nm, about 500 nm to about It may be, but is not limited to, about 800 nm, about 500 nm to about 700 nm, about 500 nm to about 600 nm, about 600 nm to about 1 μm, about 600 nm to about 900 nm, about 600 nm to about 800 nm, about 600 nm to about 700 nm, about 700 nm to about 1 μm, about 700 nm to about 900 nm, about 700 nm to about 800 nm, about 800 nm to about 1 μm, about 800 nm to about 900 nm, or about 900 nm to about 1 μm.

[0107] In one embodiment of the present invention, the bismuth precursor compound of the present invention included in the film-forming composition can be used as a precursor of an atomic layer deposition method or a chemical vapor deposition method to form a bismuth-containing film due to its low density and high thermal stability, and in particular, can uniformly form a bismuth-containing film having a thickness of several μm to several tens of nm on a substrate having a pattern (groove) on the surface, a porous substrate, or a plastic substrate, in a temperature range of from room temperature to about 500°C, from about 200°C to about 400°C, from about 300°C to about 400°C, from room temperature to about 500°C, from about 200°C to about 500°C, or from about 300°C to about 500°C, and can form a bismuth-containing film having a thickness of several μm to several tens of nm on the surface of the deepest part of a fine pattern (groove) having an aspect ratio of about 1 to about 100, or from about 1 to about 50, and a width of about 1 μm to about 10 nm or less, and the fine pattern (groove) It has an excellent effect of being able to uniformly form a bismuth-containing oxide film or nitride film having a thickness of several μm to several tens of nm or less on the entire surface of the substrate, including the surface of the fine irregularities (grooves) including the upper surface of the irregularities (grooves).

[0108] In one embodiment of the present invention, the method for forming the bismuth-containing film preferably comprises accommodating a substrate (substrate) in a reaction chamber, and then transporting the bismuth precursor compound onto the substrate using a carrier gas or a diluting gas to deposit a bismuth-containing oxide film or nitride film at a wide range of deposition temperatures from room temperature to about 500°C, or from about 200°C to about 400°C. However, the present invention may not be limited thereto.

[0109] In one embodiment of the present invention, the deposition temperature is from room temperature to about 500°C, or from about 200°C to about 400°C, because the process temperature that can be applied to memory devices, logic devices, and display devices is wide, so that the film has a high applicability to various fields, and because the film characteristics of bismuth-containing oxide thin films or nitride thin films are different, a bismuth precursor compound that can be used in a wide temperature range is required, so that the deposition is preferably performed at a deposition temperature range of from room temperature to about 500°C, or from about 200°C to about 400°C. However, it may not be limited thereto.

[0110] In one embodiment of the present invention, it is preferable to use one or more mixed gases selected from argon (Ar), nitrogen (N2), helium (He), or hydrogen (H2) as the carrier gas or diluting gas. However, it may not be limited thereto.

[0111] In one embodiment of the present invention, the method for forming the bismuth-containing film may include a step of supplying the bismuth precursor compound into a reaction chamber using a method including at least one selected from the group consisting of a bubbling method, a liquid delivery system (LDS) method, a vapor flow control (VFC) method, and a bypass method.

[0112] In one embodiment of the present invention, the method for forming the bismuth-containing film may include a step of supplying the bismuth precursor compound into the reaction chamber using a method including at least one selected from the group consisting of a bubbling method for forcibly vaporizing the precursor compound using a carrier gas, a liquid delivery system (LDS) method for supplying the precursor compound in a liquid state at room temperature and vaporizing it through a vaporizer, and a vapor flow controller (VFC) method for directly supplying the precursor compound using the vapor pressure of the precursor.

[0113] For example, when the vapor pressure is high, the VFC method can be used, and when the vapor pressure is low, the bypass method, which heats the container to vaporize, can be used.

[0114] The step of supplying the above bismuth precursor compound into the reaction chamber can be performed using a carrier gas or dilution gas in a temperature range of 0.1 to 10 torr and room temperature to 150°C.

[0115] For example, a method may be used in which the bismuth precursor compound is placed in a bubbler container or a VFC container and supplied into the chamber by bubbling or transporting it under high vapor pressure using a carrier gas at a temperature range of about 0.1 torr to about 10 torr and room temperature to about 150°C. Most preferably, an LDS method may be used in which the bismuth precursor compound is supplied in a liquid state at room temperature and vaporized through a vaporizer. However, the present invention may not be limited thereto.

[0116] In one embodiment of the present invention, it is more preferable to transport the bismuth precursor compound using argon (Ar) or nitrogen (N2) gas, use thermal energy or plasma, or apply a bias to the substrate to vaporize the bismuth precursor compound. However, the present invention may not be limited thereto.

[0117] In one embodiment of the present invention, during the deposition, thermal energy or plasma may be used, or a bias may be applied to the substrate.

[0118] In one embodiment of the present invention, when depositing the bismuth-containing film, at least one selected from the group consisting of nitrogen (N2), nitrogen plasma (N2Plasma), ammonia (NH3), ammonia plasma (NH3Plasma), hydrazine (N2H4), dimethyl hydrazine (C2H8N2), hydrogen (H2), hydrogen plasma (H2Plasma), water vapor (H2O), oxygen (O2), oxygen plasma (O2Plasma), nitric oxide (NO, N2O), nitric oxide plasma (N2O Plasma), oxygen nitride (N2O2), hydrogen peroxide (H2O2), and ozone (O3) may be used.

[0119] Specifically, in order to form a bismuth-containing nitride film (BiN) during the deposition of the bismuth-containing film, it is preferable to use ammonia (NH3), ammonia plasma (NH3Plasma), hydrazine (N2H4), or nitrogen plasma (N2Plasma) as the reaction gas. However, the present invention may not be limited thereto.

[0120] In one embodiment of the present invention, when depositing the bismuth-containing film, in order to form the bismuth-containing oxide film (Bi2O5), it is preferable to use one or a mixture of two or more selected from water vapor (H2O), oxygen (O2), oxygen plasma (O2Plasma), nitrogen oxide (NO, N2O), nitrogen oxide plasma (N2O Plasma), oxygen nitride (N2O2), hydrogen peroxide (H2O2), and ozone (O3) as a reaction gas. However, it may not be limited thereto.

[0121] A bismuth-containing film according to one embodiment of the present invention, when applied to a dielectric layer, may have a characteristic of increasing a dielectric constant. For example, compared to the dielectric constant of a dielectric layer to which the bismuth-containing film is not applied, the increase rate of the dielectric constant of the dielectric layer to which the bismuth-containing film is applied may be 5% or more, further 8% or more, and specifically 8% to 30%.

[0122] In addition, the bismuth-containing film according to one embodiment of the present invention, when applied to a dielectric layer, may have a characteristic of reducing leakage current. For example, the reduction rate of leakage current of a dielectric layer to which a bismuth-containing film is applied may be 30% or more, further 50% or more, and specifically 50% to 80%, compared to the leakage current of a dielectric layer to which a bismuth-containing film is not applied.

[0123] Therefore, the bismuth-containing film according to one embodiment of the present invention can be applied to a metal-insulator-metal (MIM) structure. In addition, the bismuth-containing film according to one embodiment of the present invention can be applied to a dielectric film of a DRAM capacitor.

[0124] The present invention is described in more detail by the following examples. The following examples are merely illustrative of the present invention and are not intended to limit the scope of the present invention.

[0125]

[0126] [Example]

[0127] <Example 1> Preparation of 3-dimethylaminopropyl-dimethyl bismuth: Me2NCH2CH2CH2BiMe2

[0128] [Chemical Formula 1-1]

[0129]

[0130] In a flame-dried 500 mL round-bottom flask, 12.0 g (0.49 mol) of magnesium powder was dispersed in 200 mL of tetrahydrofuran (THF). 30 g (0.25 mol) of 3-dimethylaminopropyl chloride was slowly added using a syringe at room temperature, and the mixture was refluxed for 12 hours with stirring to synthesize the Grignard reagent. After the reaction was complete, the mixture was cooled to 0 to 10°C. While cooling, 65 g (0.20 mol) of bismuth chloride (BiCl3) was added to another flame-dried 1 L round-bottom flask and dissolved in 100 mL of tetrahydrofuran (THF). The bismuth chloride solution in the second flask was added to the cooled solution in the first flask using a cannula, and the mixture was slowly warmed to room temperature with stirring, and stirred for 12 hours. After the reaction was completed, the solution was cooled to around -40℃, and 152 g (0.45 mol) of methylmagnesium chloride (MeMgCl, 3.0 M in THF) dissolved in tetrahydrofuran (THF) at a concentration of 3.0 mol was added using a cannula, and the temperature was slowly raised to room temperature while stirring, and then stirred for 12 hours. After the reaction was completed, the salt produced during the reaction was filtered off, and the solvent was removed under reduced pressure, and then distilled under reduced pressure to obtain 31 g (yield 46.24%) of 3-dimethylaminopropyl-dimethylbismuth (Me2NCH2CH2CH2BiMe2), a colorless liquid compound represented by the chemical formula 1-1.

[0131]

[0132]

[0133] <Example 2> Preparation of 3-dimethylamino-2-methylpropyl-dimethyl bismuth: Me2NCH2CHCH3CH2BiMe2

[0134] [Chemical Formula 1-2]

[0135]

[0136] In a flame-dried 3 L round-bottom flask, 43.0 g (1.77 mol) of magnesium powder was dispersed in 1000 mL of tetrahydrofuran (THF). 120 g (0.88 mol) of 3-dimethylamino-2-methylpropyl chloride was slowly added using a syringe at room temperature, and the mixture was refluxed for 12 hours with stirring to synthesize the Grignard reagent. After the reaction was complete, the mixture was cooled to approximately 0 to 10°C. While cooling, 280 g (0.87 mol) of bismuth chloride (BiCl3) was added to another flame-dried 5 L round-bottom flask and dissolved in 1000 mL of tetrahydrofuran (THF) to prepare in advance. The bismuth chloride solution in the second flask was added to the cooled solution in the first flask using a cannula, and the temperature was slowly raised to room temperature while stirring, and the mixture was stirred for 12 hours. After the reaction was completed, the solution was cooled to around -40℃, and 645 g (1.91 mol) of methylmagnesium chloride (MeMgCl, 3.0 M in THF) dissolved in tetrahydrofuran (THF) at a concentration of 3.0 mol was added using a cannula, and the temperature was slowly raised to room temperature while stirring, and the mixture was stirred for 12 hours. After the reaction was completed, the salt produced during the reaction was filtered off, the solvent was removed under reduced pressure, and then distilled under reduced pressure to obtain 197 g (yield 66.74%) of 3-dimethylamino-2-methylpropyl-dimethyl bismuth (Me2NCH2CHCH3CH2BiMe2), a colorless liquid compound represented by the above chemical formula 1-2.

[0137]

[0138]

[0139] <Example 3> Preparation of 3-dimethylaminopropyl-diethyl bismuth: Me2NCH2CH2CH2BiEt2

[0140] [Chemical Formula 1-7]

[0141]

[0142] In a flame-dried 500 mL round-bottom flask, 32.0 g (0.10 mol) of bismuth chloride (BiCl3) was dispersed in 100 mL of tetrahydrofuran (THF). 103 g (0.21 mol) of ethylmagnesium chloride (EtMgCl, 2.0 M in THF), which was dissolved in THF at a concentration of 2 molarity, was added via a cannula. The mixture was slowly warmed to room temperature while stirring, and stirred for 12 hours. After the reaction was completed, the mixture was cooled to approximately 0 to 10°C. To the cooled solution, 15 g (0.1 mol) of 3-dimethylaminopropyl chloride, a Grignard reagent synthesized in advance in the same manner as in Example 1, was added via a cannula. The mixture was slowly warmed to room temperature while stirring, and the mixture was stirred for 12 hours. After the reaction was completed, the salt produced during the reaction was filtered off, the solvent was removed under reduced pressure, and then the mixture was distilled under reduced pressure to obtain 8.4 g (yield 23.58%) of 3-dimethylaminopropyl-diethyl bismuth (Me2NCH2CH2CH2BiEt2), a colorless liquid compound represented by the chemical formula 1-7.

[0143]

[0144]

[0145] <Example 4> Preparation of tris(3-dimethylaminopropyl)bismuth: [Me2N(CH2)3]3Bi

[0146] [Chemical Formula 1-13]

[0147]

[0148] In a flame-dried 1 L round-bottom flask, 23.6 g (0.97 mol) of magnesium powder was dispersed in 400 mL of tetrahydrofuran (THF). 59 g (0.49 mol) of 3-dimethylaminopropyl chloride was slowly added using a syringe at room temperature, and the mixture was refluxed for 12 hours with stirring to synthesize the Grignard reagent. In another flame-dried 1 L round-bottom flask, 24.9 g (0.19 mol) of bismuth chloride (BiCl3) was prepared in advance by dissolving it in 100 mL of tetrahydrofuran (THF). The bismuth chloride solution in the second flask was added to the cooled solution in the first flask using a cannula, and the mixture was slowly warmed to room temperature with stirring, and stirred for 12 hours. After the reaction was complete, the mixture was cooled to approximately 0 to 10°C. The salt produced during the reaction was filtered off and the solvent was removed under reduced pressure, and then distilled under reduced pressure to obtain 8 g (yield 11.96%) of tris(3-dimethylaminopropyl)bismuth [Me2N(CH2)3]3Bi, a pale yellow liquid compound represented by the chemical formula 1-13.

[0149]

[0150]

[0151] <Comparative Example 1>

[0152] Preparation of tris(ethyl)bismuth:(Et)3Bi

[0153]

[0154] English: 100 g (0.31 mol) of bismuth chloride (BiCl3) was placed in a flame-dried 1 L round bottom flask and dissolved in 200 ml of tetrahydrofuran (THF) to prepare in advance. After cooling the solution to around 40°C, 338 g (0.99 mol) of ethylmagnesium bromide (EtMgBr, 3.0 M in diethyl ether) dissolved in a 3.0 molar concentration in diethyl ether was added using a cannula. The mixture was slowly warmed to room temperature with stirring and refluxed for 12 hours. After completion of the reaction, the salt produced during the reaction was filtered off, the solvent was removed under reduced pressure, and the mixture was distilled under reduced pressure to obtain 50 g (yield 54%) of tris(ethyl)bismuth (Et)3Bi as a pale yellow transparent liquid compound.

[0155]

[0156]

[0157] [Experimental Example]

[0158] <Experimental Example 1> Analysis of thermal properties of bismuth precursor compounds

[0159] To evaluate the volatility and thermal stability of the bismuth precursor compounds manufactured in Examples 1 and 2, thermal gravimetry analysis (TGA) was performed, and the results are shown in Fig. 2.

[0160] As can be seen in FIG. 2, the bismuth precursor compounds of Examples 1 and 2 were all vaporized without leaving residue as the temperature increased, indicating that they are thermally stable and suitable for use as bismuth precursors for forming bismuth-containing films using chemical vapor deposition (CVD) or atomic layer deposition (ALD).

[0161]

[0162] <Experimental Example 2> Analysis of the thermal decomposition characteristics of a bismuth precursor compound in an atomic layer deposition (ALD) process performed without a reactant.

[0163] The thermal decomposition characteristics of the bismuth precursor compounds of Example 1 and Comparative Example 1 were compared through an atomic layer deposition (ALD) process performed without a reactant using the bismuth precursor compounds of Example 1 and Comparative Example 1.

[0164] The bismuth precursor compounds of Example 1 and Comparative Example 1 were used by heating them in stainless steel containers. Comparative Example 1 was used by heating them at 30°C and Example 1 was used by heating them at 45°C. The process pressure of the reactor was maintained at 1 torr, and the precursor compounds were supplied to the reaction chamber in a gaseous state using approximately 300 sccm of argon (Ar) carrier gas. Bismuth-containing films were independently formed on two substrates, TiN and Si, and the thermal decomposition characteristics were evaluated. The process conditions are summarized in Table 1, and the results are shown in Figs. 3 and 4 and Table 2.

[0165] As shown in Table 1, the gas supply cycle consisting of supplying a bismuth precursor compound to two substrates, TiN and Si, for about 15 to 30 seconds → supplying argon (Ar) gas for about 30 seconds and removing the bismuth precursor compound (gas) remaining in the reactor was repeated 100 times to compare the thermal decomposition characteristics of the bismuth precursor compound on the two substrates.

[0166] Specifically, in order to compare the thermal decomposition characteristics according to the temperature (process temperature) of 250°C to 340°C for Example 1 and 220°C to 300°C for Comparative Example 1, the increase / decrease rate in areal density was measured, and the results are shown in FIGS. 3 and 4 and Table 2.

[0167] As can be seen in FIGS. 3 and 4 and Table 2, when the bismuth precursor compound of Example 1 was used, it was found that the surface density was constant up to a relatively high temperature of 250°C or higher, and even up to 320°C, compared to when the bismuth precursor compound of Comparative Example 1 was used.

[0168] In particular, when the bismuth precursor compound of Comparative Example 1 was used, the area density was 15 ng / cm at 250°C compared to 220°C. 2 4107 ng / cm 2 It was confirmed that thermal decomposition occurred at 250°C with an increase of 27,280%, and that bismuth-containing film deposition was possible at temperatures below 220°C. On the other hand, when the bismuth precursor compound of Example 1 was used, the areal density was 51 ng / cm at 340°C compared to 320°C. 2 157 ng / cm 2 It was confirmed that thermal decomposition occurred at 340℃ with an increase of 208%, and that stable bismuth-containing film deposition was possible at temperatures below 320℃.

[0169] Through this, it was proven that the bismuth precursor compound of Example 1 of the present invention has excellent thermal stability and is a precursor capable of depositing a bismuth-containing film at a high temperature of 300°C or higher.

[0170]

[0171]

[0172]

[0173]

[0174] <Experimental Example 3> Analysis of bismuth-containing oxide film deposition characteristics of bismuth precursor compounds using the atomic layer deposition (ALD) process.

[0175] The deposition characteristics of a bismuth-containing oxide film were analyzed through an atomic layer deposition (ALD) process using the bismuth precursor compound of Example 1 above.

[0176] The bismuth precursor compound of Example 1 was placed in a stainless steel vessel and heated to 45°C for use. The process pressure of the reactor was maintained at 1 torr, and the precursor compound was supplied to the reaction chamber in a gaseous state using approximately 200 sccm of argon (Ar) carrier gas. A bismuth-containing oxide film was formed on a TiN substrate and its characteristics were evaluated. The process conditions are summarized in Table 3, and the results are shown in Fig. 4.

[0177] As shown in Table 3, the bismuth precursor compound was supplied to the TiN substrate at a process temperature of 300°C for about 15 seconds → argon (Ar) gas was supplied for about 10 seconds to remove the bismuth precursor compound (gas) remaining in the reactor → ozone (O3) was supplied as a reaction gas for about 5 seconds → argon (Ar) gas was supplied for about 10 seconds to remove the ozone (O3) gas remaining in the reactor. The gas supply cycle was repeated 100 times to analyze the deposition characteristics of a bismuth-containing oxide film of a bismuth precursor compound on a TiN substrate.

[0178] FIG. 5 is a transmission electron microscope (TEM) image of a bismuth-containing oxide film formed on a TiN substrate at a process temperature of 300°C by atomic layer deposition (ALD) using a bismuth precursor compound of Example 1 of the present invention and ozone (O3). The thickness of the bismuth-containing oxide film measured at the portion indicated in FIG. 5 was confirmed to be 13 Å, and the film growth per ALD gas supply cycle (GPC) was confirmed to be 0.13 Å / cycle by dividing the measured thickness by the number of gas supply cycles (100 times).

[0179] Through this, it was proven that the bismuth precursor compound of Example 1 of the present invention is a precursor capable of depositing a bismuth-containing oxide film at a temperature of 300°C.

[0180] In addition, considering that the process temperature in the High-k dielectric film formation process of a DRAM capacitor is 300°C or higher, a bismuth precursor compound that can be stably deposited at a temperature of 300°C or higher is required to form a bismuth-containing film in the High-k dielectric film through an in-situ process. The bismuth precursor compound of the embodiment of the present invention exhibits stable deposition characteristics at a temperature of 300°C or higher, and thus, it can be confirmed that it is a bismuth precursor compound suitable for forming a bismuth-containing film in-situ in the High-k dielectric film formation process of a DRAM capacitor.

[0181]

[0182]

[0183] <Experimental Example 4> Analysis of Electrical Characteristics Following the Introduction of a Bismuth-Containing Oxide Film to a MIM (Metal-Insulator-Metal) Capacitor

[0184] Using the bismuth precursor compound of Example 1, a bismuth-containing oxide film was deposited through an atomic layer deposition (ALD) process, and the bismuth-containing oxide film was introduced into a metal-insulator-metal (MIM) capacitor to evaluate its electrical characteristics. In addition, the electrical characteristics were compared and analyzed when the bismuth-containing oxide film was positioned on the upper electrode and when it was positioned on the lower electrode by changing the deposition order of the bismuth-containing film.

[0185] Schematic diagrams are shown in Figs. 6 to 8 to explain the structure of a MIM (Metal-insulator-metal) capacitor fabricated to compare and analyze the electrical characteristics of bismuth-containing oxide films. As can be seen in the schematic diagrams of Figs. 6 to 8, TiN layers constitute the upper and lower electrodes, and a dielectric layer (ZrO2: zirconium-containing oxide film, Bi2O3: bismuth-containing oxide film) is formed between the electrodes.

[0186] Specifically, Fig. 6 shows a structure in which a dielectric film is formed using a single layer of a zirconium-containing oxide film. As can be seen in Fig. 6, the dielectric layer does not include a bismuth-containing oxide film, and a zirconium-containing oxide film monolayer was formed between the upper and lower electrodes (TiN) through an atomic layer deposition (ALD) process of 65 cycles. This sample was used as a reference for comparing changes in electrical characteristics according to the introduction and location (upper or lower electrode) of a bismuth-containing oxide film within the dielectric layer.

[0187] Figure 7 illustrates a structure in which a bismuth-containing oxide film is introduced between the upper electrode and the zirconium-containing oxide film. As can be seen in Figure 7, a bismuth-containing oxide film layer is formed between the upper electrode and the zirconium-containing oxide film, and this allows for analysis of changes in electrical characteristics when the bismuth-containing oxide film is introduced to the upper electrode. In addition, by comparing the influence of the bismuth-containing oxide film according to the number of ALD deposition cycles (10 to 60 cycles), it is possible to derive optimal deposition conditions.

[0188] Figure 8 shows a structure in which a bismuth-containing oxide film is introduced between the lower electrode and the zirconium-containing oxide film. As can be seen in Figure 8, a bismuth-containing oxide film layer is formed between the lower electrode and ZrO₂, and this allows for analysis of changes in electrical characteristics when the bismuth-containing oxide film is introduced to the lower electrode. Similarly, by comparing the influence of the bismuth-containing oxide film according to the number of ALD deposition cycles (10 to 60 cycles), the optimal bismuth-containing oxide film introduction conditions according to the electrode position can be evaluated.

[0189] In order to analyze the dielectric constant and leakage current characteristics of MIM (Metal-insulator-metal) capacitors, samples were fabricated and evaluated not only in the as-deposited (As-Dep.) state but also in the post-deposition annealing (PDA) state at 500°C for 30 seconds. Here, the As-Dep. state refers to the thin film in its original state without any additional heat treatment or subsequent process after deposition. Through this, the effect of post-annealing (PDA) on the electrical performance of bismuth-containing oxide films was analyzed. In addition, the electrical characteristics were evaluated according to the position (upper electrode or lower electrode) of the bismuth-containing oxide film.

[0190] To form a zirconium-containing oxide film, a CpZr(NMe2)3 precursor compound was used in a stainless steel container, and a zirconium-containing oxide film was formed through an atomic layer deposition (ALD) process with 65 cycles at a process temperature of 280°C.

[0191] To form a bismuth-containing oxide film, the bismuth precursor compound of Example 1 was placed in a stainless steel container and heated to 45°C for use. The process temperature of the reactor was maintained at 280°C and the pressure at 1 torr, and the precursor compound was supplied to the reaction chamber in a gaseous state using approximately 200 sccm of argon (Ar) carrier gas. When the bismuth-containing film was positioned on the upper electrode, a bismuth-containing film was formed on a zirconium-containing oxide film formed on the lower electrode, and when the bismuth-containing film was positioned on the lower electrode, a bismuth-containing film was formed on a TiN substrate. Specifically, a bismuth-containing oxide film was formed by repeating the gas supply cycle consisting of supplying a bismuth precursor compound for about 10 seconds → supplying argon (Ar) gas for about 30 seconds to remove the bismuth-containing oxide film precursor remaining in the reactor → supplying ozone (O₃) as a reaction gas for about 6 seconds → supplying argon (Ar) gas for about 15 seconds to remove the ozone (O₃) gas remaining in the reactor, and a MIM (Metal-insulator-metal) capacitor was manufactured, and the dielectric constant and leakage current characteristics were analyzed. The results are shown in Figs. 9 to 12 and Tables 4 to 7.

[0192] Figure 9 and Table 4 show the results of comparing the dielectric constant according to the number of bismuth-containing oxide film deposition cycles in the As-Dep. state. The analysis was performed based on a +0.7 V voltage condition, and it was confirmed that a similar trend was observed even at -0.7 V. In the case of the sample without the bismuth-containing oxide film (0 cycle), the dielectric constant was approximately 32.5, and when the bismuth-containing oxide film was introduced to the upper electrode for 10 cycles, the dielectric constant increased to 36.2. This is an increase of approximately 11.39%. Thereafter, as the amount of bismuth-containing oxide film deposited increased, the change in the dielectric constant slowed down relatively. In addition, the effect of increasing the dielectric constant was more pronounced when the bismuth-containing oxide film was located on the upper electrode than when it was located on the lower electrode.

[0193] Figure 10 and Table 5 show the change in leakage current according to the number of bismuth-containing oxide film deposition cycles in the As-Dep. state. The analysis was compared based on the +0.7 V voltage condition, and although a generally similar trend was observed at -0.7 V, some differences were confirmed in the As-Dep. state. In the case of the sample without the bismuth-containing oxide film (0 cycle), the leakage current was measured at the level of 1.78697E-8, and when the bismuth-containing oxide film was introduced to the upper electrode for 10 cycles, the leakage current decreased to 6.76312E-9. This is a decrease of approximately 62.15%. Thereafter, as the amount of bismuth-containing oxide film deposition increased, the change in leakage current slowed relatively. In addition, the effect of reducing leakage current was more pronounced when the bismuth-containing oxide film was located on the upper electrode than when it was located on the lower electrode.

[0194] Figure 11 and Table 6 show the results of comparing the dielectric constant at the upper electrode after performing post deposition annealing (PDA) at 500°C for 30 seconds. The analysis was performed based on the +0.7 V voltage condition, and almost the same trend was observed at -0.7 V. In the case of the sample without a bismuth-containing oxide film (0 cycle), the dielectric constant increased to 39.4 after the post deposition annealing (PDA), and when the bismuth-containing oxide film was introduced to the upper electrode for 10 cycles, the dielectric constant increased to 42.5. This is an increase of approximately 7.87%. Afterwards, as the amount of bismuth-containing oxide film deposited increased, the change in the dielectric constant slowed down.

[0195] Figure 12 and Table 7 show the results comparing the leakage current changes after performing post-heat treatment (PDA) at 500°C for 30 seconds. The analysis was performed based on a +0.7 V voltage condition, and almost the same trend was observed at -0.7 V. In the case of the sample without a bismuth-containing oxide film (0 cycle), the leakage current increased to 7.82E-08 after the post-heat treatment (PDA), and when the bismuth-containing oxide film was introduced to the upper electrode for 10 cycles, the leakage current decreased to 4.45E-08. This represents a decrease of approximately 43.09%. When the bismuth-containing oxide film was introduced to the upper electrode for 20 cycles, the leakage current reduction was the highest at 76.34%, and as the amount of bismuth-containing oxide film deposited thereafter increased, the leakage current tended to increase.

[0196] Through this, it was confirmed that when a bismuth-containing oxide film deposited using the bismuth precursor compound of Example 1 of the present invention is introduced into a DRAM capacitor High-k dielectric film, the electrical characteristics of the dielectric film can be effectively improved.

[0197] In addition, it was confirmed that introducing a bismuth-containing oxide film for 10 cycles showed the most effective result in improving the dielectric constant and reducing the leakage current, and that it is a deposition condition suitable for application of a high-k dielectric film to a DRAM capacitor. In particular, introducing a bismuth-containing oxide film for 10 cycles to the upper electrode, whether in the As-Dep. state or in the post-annealing (PDA) state, showed the most effective result, and it was found to achieve the optimal balance of increasing the dielectric constant and reducing the leakage current. Therefore, it can be confirmed that the bismuth precursor compound of Example 1 of the present invention is a bismuth precursor compound suitable for improving the electrical characteristics of a high-k dielectric film of a DRAM capacitor.

[0198]

[0199]

[0200]

[0201]

[0202]

[0203]

[0204]

[0205]

Claims

1. A bismuth precursor compound represented by the following chemical formula 1: [Chemical Formula 1] In the above chemical formula 1, X is And, m is an integer from 1 to 3, R1 is a hydrogen atom, a linear or branched C1-C4 alkyl group, -NR 10 R 11 and -OR 12 is selected as a group consisting of, R2 to R 12 are each independently selected from the group consisting of a hydrogen atom and a linear or branched C1-C4 alkyl group, R a and R b are each independently selected from the group consisting of a hydrogen atom and a linear or branched C1-C4 alkyl group, or R a and R b are linked to each other to form a 4-8 membered heterocycle with the N atom to which they are bonded, R c is selected from the group consisting of hydrogen atoms and linear or branched C1-C4 alkyl groups, n is an integer from 0 to 2.

2. In paragraph 1, A bismuth precursor compound, which is a compound represented by one of the following chemical formulas:

3. A composition for forming a bismuth-containing film, comprising a bismuth precursor compound represented by the following chemical formula 1 and used for deposition of a bismuth-containing film: [Chemical Formula 1] In the above chemical formula 1, X is And, m is an integer from 1 to 3, R1 is a hydrogen atom, a linear or branched C1-C4 alkyl group, -NR 10 R 11 and -OR 12 is selected as a group consisting of, R2 to R 12 are each independently selected from the group consisting of a hydrogen atom and a linear or branched C1-C4 alkyl group, R a and R b are each independently selected from the group consisting of a hydrogen atom and a linear or branched C1-C4 alkyl group, or R a and R b are linked to each other to form a 4-8 membered heterocycle with the N atom to which they are bonded, R c is selected from the group consisting of hydrogen atoms and linear or branched C1-C4 alkyl groups, n is an integer from 0 to 2.

4. In paragraph 3, A composition for forming a bismuth-containing film, wherein the bismuth precursor compound comprises at least one selected from the group consisting of compounds represented by the following chemical formula:

5. A method for forming a bismuth-containing film, comprising the step of depositing a bismuth-containing film using a composition for forming a bismuth-containing film, the composition including a bismuth precursor compound represented by the following chemical formula 1: [Chemical Formula 1] In the above chemical formula 1, X is And, m is an integer from 1 to 3, R1 is a hydrogen atom, a linear or branched C1-C4 alkyl group, -NR 10 R 11 and -OR 12 is selected as a group consisting of, R2 to R 12 are each independently selected from the group consisting of a hydrogen atom and a linear or branched C1-C4 alkyl group, R a and R b are each independently selected from the group consisting of a hydrogen atom and a linear or branched C1-C4 alkyl group, or R a and R b are linked to each other to form a 4-8 membered heterocycle with the N atom to which they are bonded, R c is selected from the group consisting of hydrogen atoms and linear or branched C1-C4 alkyl groups, n is an integer from 0 to 2.

6. In paragraph 5, A method for forming a bismuth-containing film, wherein the bismuth precursor compound comprises at least one selected from the group consisting of compounds represented by the following chemical formula:

7. In paragraph 5, The above bismuth-containing film includes at least one selected from the group consisting of a bismuth-containing metal film, a bismuth-containing oxide film, a bismuth-containing nitride film, a bismuth-containing sulfide film, and a bismuth-containing carbide film, A method for forming a bismuth-containing film, wherein, during the above deposition, at least one selected from the group consisting of nitrogen (N2), nitrogen plasma (N2Plasma), ammonia (NH3), ammonia plasma (NH3Plasma), hydrazine (N2H4), dimethyl hydrazine (C2H8N2), hydrogen (H2), hydrogen plasma (H2Plasma), water vapor (H2O), oxygen (O2), oxygen plasma (O2Plasma), nitric oxide (NO, N2O), nitric oxide plasma (N2O Plasma), oxygen nitride (N2O2), hydrogen peroxide (H2O2), and ozone (O3) is used.

8. In paragraph 5, A method for forming a bismuth-containing film, wherein the bismuth-containing film is deposited by chemical vapor deposition (CVD) or atomic layer deposition (ALD).

9. In paragraph 5, A method for forming the bismuth-containing film, comprising a step of supplying the bismuth precursor compound into a reaction chamber using a method including at least one selected from the group consisting of a bubbling method, a liquid delivery system (LDS) method, a vapor flow control (VFC) method, and a bypass method.

10. In paragraph 9, A method for forming a bismuth-containing film, wherein the step of supplying the bismuth precursor compound into the reaction chamber is performed using a carrier gas or a dilution gas in a temperature range of 0.1 to 10 torr and room temperature to 150°C.

11. In paragraph 5, A method for forming a bismuth-containing film, wherein the bismuth-containing film is formed at a temperature range of room temperature to 500°C.

12. In paragraph 5, A method for forming a bismuth-containing film, wherein the bismuth-containing film is formed in a thickness range of 0.1 nm to 500 nm.

13. In paragraph 5, A method for forming a bismuth-containing film, wherein the bismuth-containing film is formed on a substrate including one or more unevennesses having an aspect ratio of 1 or more and a width of 1 ㎛ or less.

14. In paragraph 5, A method for forming a bismuth-containing film, wherein thermal energy or plasma is used during the above deposition, or a bias is applied to the substrate.

15. A bismuth-containing film formed using a composition for forming a bismuth-containing film comprising a bismuth precursor compound represented by the following chemical formula 1: [Chemical Formula 1] In the above chemical formula 1, X is And, m is an integer from 1 to 3, R1 is a hydrogen atom, a linear or branched C1-C4 alkyl group, -NR 10 R 11 and -OR 12 is selected as a group consisting of, R2 to R 12 are each independently selected from the group consisting of a hydrogen atom and a linear or branched C1-C4 alkyl group, R a and R b are each independently selected from the group consisting of a hydrogen atom and a linear or branched C1-C4 alkyl group, or R a and R b are linked to each other to form a 4-8 membered heterocycle with the N atom to which they are bonded, R c is selected from the group consisting of hydrogen atoms and linear or branched C1-C4 alkyl groups, n is an integer from 0 to 2.

16. In paragraph 15, The above bismuth-containing film is a bismuth-containing film having the property of increasing a dielectric constant when applied to a dielectric layer.

17. In paragraph 15, The above bismuth-containing film is a bismuth-containing film having the property of reducing leakage current when applied to a dielectric layer.

18. In paragraph 15, The above bismuth-containing film is a bismuth-containing film applied to a metal-insulator-metal (MIM) structure.

19. In paragraph 15, The above bismuth-containing film is a bismuth-containing film applied to a dielectric film of a DRAM capacitor.

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