Organotin compounds for thin film deposition and method for forming tin-containing thin films using the same

Abstract

To provide a thin film forming method for depositing a good quality thin film using an organotin compound.SOLUTION: An organotin compound is represented by the following formula, where L1 and L2 are independently selected from an alkoxy group and an alkylamino group, R1 is a substituted / unsubstituted C6-8 aryl group, and R2 is selected from a substituted / unsubstituted C1-4 linear alkyl group, a C2-4 allyl group and the like.SELECTED DRAWING: Figure 2a

Description

[Technical Field]

[0001] The present invention relates to organotin compounds and a method for forming tin-containing thin films using the same, and more particularly to organotin compounds used as precursors for thin film deposition and a method for forming tin-containing thin films using the same. [Background technology]

[0002] With advancements in electronic technology, the miniaturization and weight reduction of electronic elements used in various electronic devices are progressing rapidly. As electronic elements become faster and more power-efficient, the semiconductor elements they incorporate are also required to have faster operating speeds and lower drive voltages. To meet these demands, a variety of lithography processes have been developed that can form fine circuits for the production of nanoscale semiconductor elements for next-generation semiconductor devices.

[0003] For example, extreme ultraviolet (EUV) lithography uses 13.5 nm wavelength extreme ultraviolet light as a light source, making it easy to create extremely fine circuits on wafers with a limited area, and is attracting attention as a lithography process for next-generation semiconductor devices.

[0004] On the other hand, to manufacture microelectronic devices, various physical and chemical deposition methods are used to form metal thin films, metal oxide thin films, or metal nitride thin films. Generally, thin films containing metal are formed using metal-organic chemical vapor deposition (MOCVD) or atomic layer deposition (ALD) processes. Compared to the MOCVD process, the ALD process exhibits a self-limiting reaction, resulting in superior step coverage, and because it is a relatively low-temperature process, it can avoid degradation of device characteristics due to thermal diffusion.

[0005] As described above, thin films are formed by depositing metal precursor materials, and in order to easily manufacture microelectronic devices, they must satisfy a variety of physical properties, such as appropriate and robust thermal stability, high reactivity, vapor pressure, and long-term stability. However, the development of suitable metal precursors and thin films that can form thin films of uniform thickness in a miniaturized three-dimensional structure is currently limited. [Overview of the Initiative] [Problems that the invention aims to solve]

[0006] The object of the present invention is to provide an organotin compound that is suitable for thin film growth, has robust thermal stability, possesses a high vapor pressure, exists in a liquid state at room temperature, and is easy to store and handle. Another object of the present invention is to provide a precursor composition for thin film deposition that can provide excellent physical properties using the organotin compound. Furthermore, the present invention aims to provide a thin film formation method for depositing a high-quality thin film using the precursor composition for thin film deposition.

[0007] Other objectives of the present invention will become clearer from the detailed description below. [Means for solving the problem]

[0008] An organotin compound according to one embodiment of the present invention can be represented by formula 1.

[0009] [ka]

[0010] In the above formula 1, L1 and L2 are independently selected from alkoxy groups having 1 to 10 carbon atoms and alkylamino groups having 1 to 10 carbon atoms, R1 is a substituted or unsubstituted aryl group having 6 to 8 carbon atoms, and R2 is selected from substituted or unsubstituted linear alkyl groups having 1 to 4 carbon atoms, branched alkyl groups having 3 to 4 carbon atoms, cyclic alkyl groups having 3 to 6 carbon atoms, and allyl groups having 2 to 4 carbon atoms. For example, L1 and L2 are each -N(R 11 )(R 12) and R 11 and R 12 Each of these may be a linear alkyl group having 1 to 3 carbon atoms.

[0011] The present invention provides a tin-containing precursor composition for thin film deposition, and one embodiment of the present invention provides an organotin compound represented by the formula 1 above.

[0012] A method for forming a tin-containing thin film according to one embodiment of the present invention involves using an organotin compound represented by the above formula 1 as a precursor and depositing a thin film onto a substrate through a metal-organic chemical vapor deposition (MOCVD) process or an atomic layer deposition (ALD) process. [Effects of the Invention]

[0013] An organotin compound according to one embodiment of the present invention has excellent thermal stability, exists in a liquid state at room temperature, making it easy to store and handle, and has high volatility, which is advantageous for application in thin film formation processes. Furthermore, the organotin compound of the present invention has excellent reactivity, enabling the formation of high-quality tin thin films at a fast growth rate during thin film formation. In addition, the organotin compound of the present invention effectively reduces the amount of residue in the vapor deposition process, enabling the formation of tin thin films of uniform thickness.

[0014] This makes it possible to stably form a high-quality tin thin film on a substrate using a composition containing the organotin compound of the present invention as a precursor through an atomic layer deposition process or a metal-organic chemical vapor deposition process.

[0015] As a result of the effects of the invention described above, it is possible to form a thin film of uniform thickness on the surface of a miniaturized three-dimensional structure using the organotin compound of the present invention as a precursor, and further contribute to the fabrication of nanoscale semiconductor devices. [Brief explanation of the drawing]

[0016] [Figure 1] It is a graph showing the results of nuclear magnetic resonance analysis (1H NMR) of the compound according to Example 1. [Figure 2a] It is a graph showing the results of thermogravimetric analysis (TGA) of the compound according to Example 1. [Figure 2b] It is a graph showing the results of thermogravimetric analysis (TGA) of the compound according to Comparative Example 1. [Figure 3a] It is a graph showing the results of differential scanning calorimetry (DSC) of the compound according to Example 1. [Figure 3b] It is a graph showing the results of differential scanning calorimetry (DSC) of the compound according to Comparative Example 1.

Mode for Carrying Out the Invention

[0017] The advantages, features, and the methods for achieving them of the present invention will become clear by referring to the examples described in detail below together with the accompanying drawings. However, the present invention is not limited to the examples disclosed below, and can be embodied in various different forms. Merely, these examples are provided so that the disclosure of the present invention becomes complete and that those having ordinary knowledge in the technical field to which the present invention pertains can fully know the scope of the invention. The present invention is only defined by the scope of the claims.

[0018] In explaining the present invention, when it is determined that a specific explanation of related known technologies may obscure the gist of the present invention, the detailed explanation thereof is omitted. When terms such as "including", "having", "made" etc. mentioned in the present invention are used, unless "only" is used, other parts can be added. When a component is expressed in the singular, it includes the case of including a plurality unless there is a specific description to the contrary.

[0019] In interpreting a component, it is interpreted as including an error range even without a separate specific description.

[0020] Throughout the present specification, the term "normal temperature" means a temperature of 15°C to 30°C.

[0021] Throughout this specification, the term "unsubstituted" means either having no substituents or having hydrogen atoms substituted with isotopes selected from light hydrogen, deuterium, and tritium.

[0022] Throughout this specification, the term "substitution" means that a hydrogen atom or a group of atoms in the original compound has been substituted with a substituent. For example, substituents may be selected from, but are not limited to, C1-C10 alkyl groups, C2-C12 alkenyl groups, C2-C12 alkynyl groups, C3-C12 alkynyl groups, C3-C12 cycloalkyl groups, C2-C12 heterocycloalkyl groups, C6-C20 aryl groups, C1-C12 alkoxy groups, C1-C12 alkylamino groups, C1-C12 alkyl halide groups, cyano groups, halogen groups, carboxyl groups, hydroxyl groups, carbonyl groups, amine groups, carboxyl groups, nitro groups, and combinations thereof.

[0023] Throughout this specification, the term "alkyl group" includes linear alkyl groups having 1 to 6 carbon atoms and branched alkyl groups having 3 to 6 carbon atoms. Examples of such alkyl groups include, but are not limited to, methyl group, ethyl group, n-propyl group (n-Pr), iso-propyl group (i-Pr), n-butyl group (n-Bu), tert-butyl group (t-Bu), iso-butyl group (i-Bu), sec-butyl group (s-Bu), n-pentyl group, tert-pentyl group, iso-pentyl group, sec-pentyl group, neopentyl group, 3-pentyl group, hexyl group, isohexyl group, and their isomers.

[0024] Throughout this specification, the term "alkoxy group" refers to the general formula R a It is a monovalent organic group represented by O-, where R a This may be an alkyl group having 1 to 10 carbon atoms or a branched alkyl group having 3 to 10 carbon atoms, but is not limited thereto.

[0025] Throughout this specification, the term "alkylamino group" means a monovalent amino group substituted with an alkyl group.

[0026] Throughout this specification, the term "aryl group" means a monovalent organic group derived from an aromatic hydrocarbon.

[0027] Throughout this specification, the term "allyl group" means a monovalent organic group derived from a linear or branched unsaturated hydrocarbon having two or more carbon atoms and having one or more C=C bonds.

[0028] The organotin compound according to an embodiment of the present application may be represented by the following Chemical Formula 1.

[0029]

Chemical Formula

[0030] L1 and L2 are each independently selected from an alkoxy group having 1 to 10 carbon atoms and an alkylamino group having 1 to 10 carbon atoms.

[0031] R1 is a substituted or unsubstituted aryl group having 6 to 8 carbon atoms.

[0032] R2 is selected from a linear alkyl group having 1 to 4 carbon atoms, a branched alkyl group having 3 to 4 carbon atoms, a cyclic alkyl group having 3 to 6 carbon atoms, and an allyl group having 2 to 4 carbon atoms.

[0033] In Chemical Formula 1, L1 and L2 may each independently be any one selected from -N(R 11 )(R 12 ) or -OR 13 . When L1 and L2 are -N(R 11 )(R 12 ), R 11 and R 12 may each independently be a linear alkyl group having 1 to 6 carbon atoms or a branched alkyl group having 3 to 6 carbon atoms.

[0034] Also, L1 and L2 are -OR 13 If R 13 This may be a linear alkyl group having 1 to 6 carbon atoms or a branched alkyl group having 3 to 6 carbon atoms. Furthermore, in formula 1, L1 and L2 may be the same or different from each other. For example, in formula 1, L1 and L2 are -N(R 11 )(R 12 ) may be the case. In this case, R 11 and R 12 They may also be identical or different from one another, for example, R 11 and R 12 Each of these may be a linear alkyl group having 1 to 6 carbon atoms.

[0035] More specifically, the organotin compound represented by Chemical Formula 1 may be the compound represented by Chemical Formula 2 below.

[0036] [ka]

[0037] As another example, the organotin compound represented by Chemical Formula 1 may be the compound represented by Chemical Formula 3 below.

[0038] [ka]

[0039] The organotin compound according to one embodiment of the present invention can maintain a structurally more stable state and exhibits excellent thermal stability. More specifically, the abundant electrons present in the aryl group contribute to the central metal, allowing the organotin compound to become thermally stable. Therefore, the organotin compound according to one embodiment of the present invention can be used as a precursor composition for tin-containing thin film deposition. Accordingly, a stable and high-quality tin thin film can be formed using the organotin compound according to one embodiment of the present invention as a precursor through an atomic layer deposition process or a metal-organic chemical vapor deposition process.

[0040] Furthermore, the organotin compound according to one embodiment of the present invention is in a liquid state at room temperature, making it easy to store and handle, and its high volatility is advantageous for application in thin film formation processes. When forming a thin film through a vapor deposition process, the precursor material must not decompose and must be easily transferred to the reaction chamber. The organotin compound according to one embodiment of the present invention is thermally stable and does not decompose, exists in a liquid state at room temperature, and has a high vapor pressure, making it advantageous for use in thin film deposition processes. Furthermore, the organotin compound according to one embodiment of the present invention exhibits excellent reactivity. This allows for rapid growth during thin film formation, resulting in the formation of a high-quality tin-containing thin film.

[0041] Furthermore, the organotin compound shown in Chemical Formula 1 according to the embodiment of the present invention can effectively reduce the amount of residue generated during the vapor deposition process.

[0042] Furthermore, by using an organotin compound according to one embodiment of the present invention as a precursor, a thin film of uniform thickness can be easily formed on the surface of a miniaturized three-dimensional structure.

[0043] In the following, the organotin compounds according to the present invention will be described in more detail through the following examples. However, these are presented only to aid in understanding the present invention, and the present invention is not limited to the following examples.

[0044] Example 1: Production of Sn(t-Bu)(Phenyl)[N(CH3)2]2

[0045] 314 g (0.045 mol) of Sn(t-Bu)[N(CH3)2] and 100 ml of diethyl ether were placed in a 500 ml flask and mixed. 15.91 ml (0.047 mol) of phenyl magnesium chloride in tetrahydrofuran was gradually added at approximately -70°C, and the mixture was then heated to room temperature and stirred for 8 hours. After removing the solvent and by-products by filtration and reduced pressure, the mixture was purified under conditions of 90°C and 0.2 Torr to obtain 6 g of Sn(t-Bu)(Phenyl)[N(CH3)2]2 represented by formula 2 (yield: 38%).

[0046] Nuclear magnetic resonance analysis to confirm the synthesis of the compound ( 1 Nuclear magnetic resonance (H) NMR (using C6D6 solvent) was performed, and the results are attached to Figure 1. Based on the nuclear magnetic resonance analysis results shown in Figure 1, the synthesis of compound Sn(t-Bu)(Phenyl)[N(CH3)2]2 was confirmed.

[0047] Comparative Example 1: Production of Sn(t-Bu)[N(CH3)2]3

[0048] 188.27 ml (0.466 mol) of n-butyllithium in hexane solution and 300 ml of n-hexane were added to a 1000 ml flask and mixed. 21.8 g (0.483 mol) of dimethylamine was gradually added at approximately -50°C, and the temperature was raised to room temperature. The mixture was then stirred and allowed to react for 5 hours. 30.0 g (0.115 mol) of SnCl4 was gradually added at approximately -30°C, and the temperature was raised to room temperature. The mixture was then stirred and allowed to react for 12 hours. After removing the solvent and by-products by filtration and reduced pressure, the solution was purified under conditions of 50°C and 0.3 Torr to obtain 27 g of Sn[N(CH3)2]4 (yield: 80%).

[0049] Next, 427 g (0.091 mol) of Sn[N(CH3)2] obtained above and 200 ml of diethyl ether were added to a 1000 ml flask and mixed. 48.05 ml (0.096 mol) of t-Butyl magnesium chloride in tetrahydrofuran (t-Butyl magnesium chloride in THF) was gradually added at approximately -70°C, and the mixture was then heated to room temperature and stirred for 8 hours. After removing the solvent and by-products by filtration and reduced pressure, the mixture was purified under conditions of 75°C and 0.2 Torr to obtain 14 g of Sn(t-Bu)[N(CH3)2]3 (yield: 49%).

[0050] Experimental example: Thermal analysis

[0051] Thermogravimetic analysis (TGA) and differential scanning calorimetry (DSC) were performed to investigate the thermal stability and volatility characteristics of the compounds in Example 1 and Comparative Example 1, respectively. First, for thermogravimetic analysis, a specified weight of sample was placed in a crucible, and the temperature was increased from room temperature to 350°C at a rate of 10°C / min while argon gas was injected at a pressure of 1.5 bar / min. For differential scanning calorimetry, the sample was heated to 400°C at a rate of 10°C / min while measurements were taken. The results are shown in Figures 2a, 2b, 3a, and 3b.

[0052] Figure 2a is a graph showing the thermogravimetric analysis (TGA) results of the compound according to Example 1, Figure 2b is a graph showing the thermogravimetric analysis (TGA) results of the compound according to Comparative Example 1, Figure 3a is a graph showing the differential scanning calorimetry (DSC) results of the compound according to Example 1, and Figure 3b is a graph showing the differential scanning calorimetry (DSC) results of the compound according to Comparative Example 1.

[0053] First, referring to Figure 2a, the compound Sn(t-Bu)(Phenyl)[N(CH3)2]2 of Example 1 undergoes a mass decrease from approximately 100°C, and the residual amount at 350°C is 0.7%, and the half-life (T) 1 / 2) can be confirmed to be approximately 196°C. In contrast, referring to Figure 2b, the compound Sn(t-Bu)[N(CH3)2]3 of Comparative Example 1 shows a mass decrease starting at 78°C, which is about 22°C lower than Example 1, and its half-life (T 1 / 2 The temperature was approximately 146°C, which is 50°C lower than in Example 1.

[0054] Next, referring to Figure 3a, it can be confirmed that the compound Sn(t-Bu)(Phenyl)[N(CH3)2]2 of Example 1 undergoes thermal decomposition at temperatures of approximately 210°C or higher, and referring to Figure 3b, it can be confirmed that the compound Sn(t-Bu)[N(CH3)2]3 of Comparative Example 1 begins thermal decomposition at approximately 200°C.

[0055] The experimental results above indicate that the compound according to Example 1 is more thermally stable, highly volatile, and more suitable as a precursor for forming a tin thin film through the vapor deposition process.

[0056] The following describes a method for forming a tin-containing thin film according to one embodiment of the present invention.

[0057] A method for forming a tin-containing thin film according to one embodiment of the present invention involves depositing a thin film onto a substrate through a deposition process that utilizes an organotin compound according to one embodiment of the present invention as a precursor.

[0058] The deposition process can be carried out by atomic layer deposition (ALD) or chemical vapor deposition (CVD), such as metal-organic vapor deposition (MOCVD). The deposition process can be carried out at 50 to 700°C.

[0059] First, the organotin compound represented by Formula 1 is transferred onto the substrate. For example, the organotin compound can be supplied onto the substrate by methods such as bubbling, vapor phase mass flow controller, direct gas injection (DGI), direct liquid injection (DLI), or liquid transfer by dissolving it in an organic solvent, but is not limited to these methods.

[0060] More specifically, organotin compounds can be mixed with a carrier gas or diluent gas containing one or more selected from argon (Ar), nitrogen (N2), helium (He), and hydrogen (H2), and then transferred onto a substrate by bubbling or direct gas injection.

[0061] On the other hand, when forming a tin oxide thin film, the deposition process may include a step of supplying one or more reaction gases selected from water vapor (H2O), oxygen (O2), ozone (O3), and hydrogen peroxide (H2O2). Also, when forming a tin nitride thin film, the deposition process may include a step of supplying one or more reaction gases selected from ammonia (NH3), hydrazine (N2H4), nitrous oxide (N2O), and nitrogen (N2).

[0062] Although the present invention has been described in detail through examples above, other forms of embodiment are also possible. Therefore, the technical idea and scope of the claims described below are not limited to the examples.

Claims

1. An organotin compound represented by the following chemical formula 2 or the following chemical formula 3. 【Chemistry 2】 【Transformation 3】

2. The organotin compound according to claim 1, wherein the organotin compound is liquid at room temperature.

3. A precursor composition for tin-containing thin film deposition, comprising the organotin compound described in claim 1 or 2.

4. A method for forming a tin-containing thin film, comprising using the organotin compound described in claim 1 or 2 as a precursor, and depositing a thin film onto a substrate through a Metal Organic Chemical Vapor Deposition (MOCVD) step or an Atomic Layer Deposition (ALD) step.

5. The method for forming a tin-containing thin film according to claim 4, wherein the deposition step is carried out in a temperature range of 50 to 700°C.

6. The method for forming a tin-containing thin film according to claim 4, wherein the deposition step includes a step of transferring the organotin compound to the substrate through one method selected from a bubbling method, a vapor phase mass flow controller (MFC) method, a direct gas injection (DGI) method, a direct liquid injection (DLI) method, and an organic solution supply method in which the organotin compound is dissolved in an organic solvent and then transferred.

7. The organotin compound is moved onto the substrate together with the transport gas by the bubbling method or the direct gas injection method. The transport gas is argon (Ar), nitrogen (N ２ ), helium (He) and hydrogen (H ２ A method for forming a tin-containing thin film according to claim 6, wherein the mixture contains one or more selected from among the following.

8. The aforementioned deposition process involves the formation of the tin-containing thin film using water vapor (H ２ O), oxygen (O ２ ), ozone (O ３ ) and hydrogen peroxide (H ２ O ２ A method for forming a tin-containing thin film according to claim 4, comprising the step of supplying one or more reaction gases selected from among the following.

9. The vapor deposition process includes a step of supplying one or more reaction gases selected from ammonia (NH ３ ), hydrazine (N ２ H ４ ), nitrous oxide (N ２ O), and nitrogen (N ２ ) during the formation of the tin-containing thin film. The method for forming a tin-containing thin film according to claim 4.

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