Patent Application
20250122619
The present disclosure relates to a precursor for forming an yttrium- or scandium-containing thin film, a method for forming an yttrium- or scandium-containing thin film using the same, and a semiconductor element including the yttrium- or scandium-containing thin film. More particularly, the present disclosure relates to a precursor for forming an yttrium- or scandium-containing thin film, the precursor being capable of forming a high-quality thin film by constructing a precursor with low viscosity, high thermal stability, and high volatility through a chemical structure including an amidinate ligand, to a method for forming a thin film using the same, and to a semiconductor element including the thin film.
With improved integration density achieved through the miniaturization of line widths in semiconductor elements, there is a limitation in the line width of a space allowed for the implementation of capacitor structures. Accordingly, there have been limitations with existing silicon-based dielectrics in manufacturing methods of semiconductor elements for implementing capacitor structures. In addition, with the application of high-dielectric thin films to replace silicon-based dielectrics, there have been problems in that the leakage current affected by bandgaps is significantly increased, resulting in degradation.
As one of the solutions to these problems, a technology for forming high-quality thin films is required, and therefor, precursors used for thin film formation need to be optimized.
In one example of precursor optimization methods in the art, various doping precursors that can improve properties, that is, improve permittivity and reduce leakage current, have been proposed. However, these precursors are typically either solids or liquids with low volatility and may cause many problems in thin film formation deposition processes, especially due to the high viscosity thereof. Therefore, improving the physical properties of precursors, such as high volatility, low viscosity, and the like, is a crucial task to achieve optimization of precursors for forming thin films.
To this end, various metal-containing precursors are being developed. For example, Korean Patent Application Publication No. 10-2019-0008427 has disclosed a lanthanide metal-containing precursor including an aza-allyl ligand, and Korean Patent Application Publication No. 10-2021-0089015 has disclosed an yttrium metal-containing precursor including a cyclopentadienyl ligand.
For a detailed description of such technologies known in the art, complexes containing cyclopentadienyl groups substituted or cyclopentadienyl groups to which other ligands are bound, have a lower melting point and higher volatility than compounds containing beta-diketonate or bis(trimethylsilyl)amide and thus are advantageous for use as precursors in thin film formation processes.
For this reason, known technologies, such as Korean Patent No. 10-1660052, Korean Patent Application Publication No. 10-2019-0109142, and Korean Patent Application Publication No. 10-2021-0084297, have proposed chemical structures to which cyclopentadienyl and amidinate ligands are bound, as yttrium- or lanthanide metal-containing precursors. It has been reported that precursors to which these ligands are bound can improve the disadvantages of existing precursors with low vapor pressure and high viscosity, and thus are suitable for use in thin film formation processes.
The present disclosure, which has been devised in view of technologies in the art described above, aims to provide a novel precursor for forming an yttrium- or scandium-containing thin film, which is capable of exhibiting suitable chemical properties for use as precursors for forming thin films.
In addition, the present disclosure aims to provide a precursor for forming an yttrium- or scandium-containing thin film, which exhibits chemical properties such as low viscosity, high thermal stability, and high volatility, and is a liquid at room temperature or a solid having a low melting point.
In addition, the present disclosure aims to provide a method for forming a thin film using the above precursor.
In addition, the present disclosure aims to provide a semiconductor element including the above thin film.
A precursor for forming a scandium- or yttrium-containing thin film of the present disclosure, which is provided to achieve the objectives as described above, is characterized by including a compound represented by Chemical Formula 1 below.
In Chemical Formula 1, M is an yttrium or scandium metal, R1 and R3 are each independently a straight-chain, branched-chain, or cyclic alkyl or alkenyl group having 1 to 5 carbon atoms, R2 is a hydrogen atom or a straight-chain, branched-chain, or cyclic alkyl or alkenyl group having 1 to 4 carbon atoms, each R′ is the same or different and is a hydrogen atom or a straight-chain, branched-chain, or cyclic alkyl or alkenyl group having 1 to 4 carbon atoms, and n is an integer in the range of 1 to 5.
In addition, R2 may be a straight-chain, branched-chain, or cyclic alkyl or alkenyl group having 2 to 4 carbon atoms.
In addition, R1 and R3 may each independently be a straight-chain, branched-chain, or cyclic alkyl or alkenyl group having 2 to 5 carbon atoms, and R2 may be a straight-chain, branched-chain, or cyclic alkyl or alkenyl group having 2 to 4 carbon atoms.
In addition, R1 and R3 may be methyl groups.
In addition, R2 may be an isopropyl group.
In addition, R1 and R3 may each independently be a straight-chain alkyl or alkenyl group having 1 to 5 carbon atoms.
In addition, R1 and R3 may each independently be a straight-chain alkyl or alkenyl group having 1 to 5 carbon atoms, and R2 may be a straight-chain alkyl or alkenyl group having 1 to 4 carbon atoms.
In addition, R1 and R3 may be both the same and may be alkyl or alkenyl groups.
In addition, R1 to R3 may be all the same and may be alkyl or alkenyl groups.
In addition, the precursor for forming the yttrium- or scandium-containing thin film preferably has a viscosity of 60 cP or less.
In addition, the precursor for forming the yttrium- or scandium-containing thin film preferably has a melting point of 70° C. or lower.
In addition, the precursor for forming the thin film may further include a solvent, and the solvent may be one or more of a saturated or unsaturated hydrocarbon having 1 to 16 carbon atoms, a ketone, an ether, glyme, an ester, tetrahydrofuran (THF), and a tertiary amine. In addition, the solvent may be included in an amount range of 1 to 99 wt % with respect to the total weight of the precursor for forming the thin film.
A method for forming an yttrium- or scandium-containing thin film of the present disclosure includes a process of forming a thin film on a substrate using the above precursor for forming the thin film, and the process of forming the thin film on the substrate is characterized by including the following processes: forming a precursor thin film through deposition of the precursor for forming the thin film onto the surface of the substrate, and reacting the precursor thin film with a reactive gas.
In addition, the process of forming the precursor thin film may include a process of vaporizing the precursor for forming the thin film to transfer the resulting vapor of the precursor into a chamber.
In addition, the deposition may be performed by any one process of spin-on dielectric (SOD) deposition, low-temperature plasma (LTP) deposition, chemical vapor deposition (CVD), plasma enhanced chemical vapor deposition (PECVD), high-density plasma chemical vapor deposition (HDPCVD), atomic layer deposition (ALD), or plasma enhanced atomic layer deposition (PEALD).
In addition, the process of forming the yttrium- or scandium-containing thin film on the substrate may include a step of feeding the precursor for forming the thin film onto the substrate and applying a plasma, thereby forming the thin film.
In addition, a semiconductor element of the present disclosure is characterized by including a thin film manufactured by the above method for forming the yttrium- or scandium-containing thin film.
A precursor for forming an yttrium- or scandium-containing thin film, according to the present disclosure, includes cyclopentadienyl and amidinate ligands, so the precursor compound exhibits properties such as excellent structural stability, low viscosity, high volatility, high thermal stability, and being a liquid at room temperature or being a solid having a low melting point. Therefore, the precursor exhibits physical properties suitable for use in an yttrium- or scandium-containing thin film formation process.
In addition, a high-quality yttrium- or scandium-containing thin film can be formed using the precursor, and a semiconductor element including such an yttrium- or scandium-containing thin film, manufactured by the above thin film formation method, can be provided.
Hereinafter, the present disclosure will be described in more detail. All terms or words used in the specification and the appended claims should not be construed as being limited to general and dictionary meanings, but will be interpreted based on the meanings and concepts corresponding to the technical ideas of the present disclosure on the basis of the principle that any inventor is allowed to define the terms appropriately for the best explanation.
A precursor for forming an yttrium- or scandium-containing thin film, according to the present disclosure, is characterized by including a compound of Chemical Formula 1 below.
In Chemical Formula 1, M is yttrium (Y) or scandium (Sc), R1 and R3 are each independently a straight-chain, branched-chain, or cyclic alkyl or alkenyl group having 1 to 5 carbon atoms, R2 is a hydrogen atom or a straight-chain, branched-chain, or cyclic alkyl or alkenyl group having 1 to 4 carbon atoms, each R′ is the same or different and is a hydrogen atom or a straight-chain, branched-chain, or cyclic alkyl or alkenyl group having 1 to 4 carbon atoms, and n is an integer in the range of 1 to 5.
R1 and R3 constituting an amidinate ligand in Chemical Formula 1 may be the same or different, which may be configured in various forms depending on the desired effects of the precursor that can be provided through the present disclosure.
In addition, while R2 constituting the amidinate ligand in Chemical Formula 1 may be a hydrogen atom or a straight-chain, branched-chain, or cyclic alkyl or alkenyl group having 1 to 4 carbon atoms, non-limiting examples thereof may include n-alkyl groups, such as an ethyl group, a propyl group, or a butyl group.
The compound represented by Chemical Formula 1 is a precursor having a chemical structure including the amidinate ligand, in which yttrium or scandium serves as the core metal atom. This precursor includes a cyclopentadienyl ligand providing characteristics such as a low melting point and high volatility, as well as a novel amidinate ligand having a structure that differs from those in the art. Therefore, properties such as high structural stability, low viscosity, high volatility, high thermal stability, and being a liquid at room temperature or being a solid having a low melting point can be added.
In other words, the precursor for forming the yttrium- or scandium-containing thin film, according to the present disclosure, contains yttrium or scandium as the core metal and includes heterogeneous ligands that provide each of the effects that can contribute to improving the properties of the precursor, especially the novel amidinate ligand that provides excellent effects such as structural stability, low viscosity, high volatility, high thermal stability, and being a liquid at room temperature or being a solid having a low melting point. Therefore, the precursor exhibits physical properties suitable for use in a thin film formation process and thus can form a high-quality thin film.
The precursor for forming the thin film, represented by Chemical Formula 1, may have a variety of forms with different functional groups.
In one embodiment, R2 may be a straight-chain, branched-chain, or cyclic alkyl or alkenyl group having 2 to 4 carbon atoms. When R2 is provided with 2 or more carbon atoms, the intramolecular asymmetry is increased compared to that in the case of R2 having 1 carbon atom. Accordingly, the intermolecular interference is reduced. As a result, the ligand-including precursor can facilitate the formation of a liquid or a solid having a low melting point and obtain low-viscosity properties.
In addition, R1 and R3 may each independently be a straight-chain, branched-chain, or cyclic alkyl or alkenyl group having 2 to 5 carbon atoms, and R2 may be a straight-chain, branched-chain, or cyclic alkyl or alkenyl group having 2 to 4 carbon atoms.
In addition, in one embodiment, R1 and R3 may be methyl groups, and R2 may be an isopropyl group.
In addition, R1 and R3 may each independently be a straight-chain alkyl or alkenyl group having 1 to 5 carbon atoms.
The molecular weight of straight-chain alkyl or alkenyl groups may be reduced by making ligand structures the smallest compared to those of branched-chain or cyclic groups, thereby obtaining the effects of improving volatility and vapor pressure.
Therefore, in the ligand according to one embodiment of the present disclosure, R1 and R3 may each independently be composed of a straight-chain alkyl or alkenyl group. In this case, the ligand-including precursor for forming the thin film has improved vapor pressure, so the effects, such as ease of processing, can be obtained during a thin film formation process using the precursor.
In addition to the effect of improving the vapor pressure, the ligand in which R1 and R3 are each independently composed of a straight-chain alkyl group has a high degree of structural freedom of the ligand, so the effect of improving the degree of freedom of the precursor to which the ligand is applied can be obtained. Such an effect allows interference between the precursors to be reduced to a minimum, thus exhibiting the effects of turning the precursor into a liquid and creating low-viscosity properties.
Thus, in the amidinate ligand according to one embodiment of the present disclosure, R1 and R3 in Chemical Formula 1 may be composed of straight-chain alkyl or alkenyl groups, in which case the ligand-including precursor may have improved vapor pressure. In addition, through the improvement in the degree of freedom, the formation of a liquid or a solid having a low melting point can be facilitated, and low-viscosity properties can also be obtained.
In addition, R1 and R3 may each independently be a straight-chain alkyl or alkenyl group having 1 to 5 carbon atoms, and R2 may be a straight-chain alkyl or alkenyl group having 1 to 4 carbon atoms.
In addition, R1 and R3 may be both the same and may be straight-chain, branched-chain, or cyclic alkyl or alkenyl groups having 1 to 5 carbon atoms.
In addition, R1 to R3 may be all the same and may be straight-chain, branched-chain, or cyclic alkyl or alkenyl groups having 1 to 4 carbon atoms.
Exemplary structures of the precursor for forming the thin film, represented by Chemical Formula 1, are as shown below.
In addition, the cyclopentadienyl ligand may have a substituted structure, which allows the control of the molecular size, thus controlling the viscosity and volatility of the precursor compound.
In this case, the precursor for forming the yttrium- or scandium-containing thin film preferably has a viscosity of 60 cP or less. In addition, the precursor for forming the thin film preferably has a melting point of 70° C. or lower.
The chemical structure of the precursor for forming the thin film of the present disclosure enables a liquid precursor having low viscosity, high thermal stability, and high volatility to be obtained, which allows a high-quality thin film to be formed.
In addition, the precursor for forming the thin film of the present disclosure may further include a solvent for dissolving or diluting the precursor compound in consideration of conditions and efficiency of the thin film formation process. As the solvent, any one or a mixture of a saturated or unsaturated hydrocarbon having 1 to 16 carbon atoms, a ketone, an ether, glyme, an ester, THF, and a tertiary amine may be used. Examples of the saturated or unsaturated hydrocarbon having 1 to 16 carbon atoms may include pentane, cyclohexane, ethylcyclohexane, heptane, octane, toluene, and the like, and examples of the tertiary amine may include dimethylethylamine, triethylamine, and the like.
In particular, depending on the chemical structure, the precursor compound for forming the thin film may be a solid at room temperature. In this case, by including the solvent, the compound can be dissolved. In other words, when the solvent is included, the solvent has a content enabling the precursor compound to be dissolved and is preferably included in an amount range of 1 to 99 wt % with respect to the total weight of the precursor for forming the thin film.
The precursors with or without the solvent are vaporizable and thus may be fed into a chamber in the form of precursor gas. Therefore, depending on the types of precursor compounds for forming the thin film, the precursor may be present as a liquid at room temperature and, when being easily vaporizable, the thin film formation process may be performed even without involving additional solvents.
In this case, the process of forming the scandium- or yttrium-containing thin film may be performed by any one process of SOD deposition, LTP deposition, CVD, PCVD, HDPCVD, ALD, or PALD.
For example, when being applied, the HDPCVD process may be performed at high vacuum and high power compared to an atmospheric pressure chemical vapor deposition (AP-CVD) process, a low-pressure chemical vapor deposition (LP-CVD) process, or a plasma-enhanced chemical vapor deposition (PE-CVD) process. Therefore, a thin film that is structurally dense and has excellent mechanical properties can be formed.
To this end, a method for forming a thin film, according to the present disclosure, includes a process of forming a thin film on a substrate using the above precursor for forming the thin film.
Specifically, the process of forming the yttrium- or scandium-containing thin film on the substrate may include the following processes: forming a precursor thin film through deposition of the precursor for forming the thin film onto the surface of the substrate, and reacting the precursor thin film with a reactive gas.
In addition, for the deposition of the precursor, a process of vaporizing the precursor for forming the thin film to transfer the resulting vapor of the precursor into a chamber may be included.
In addition, the process of forming the scandium- or yttrium-containing thin film on the substrate may include a process of feeding the precursor for forming the thin film onto the substrate and applying a plasma in the presence of the reactive gas, thereby forming a metal thin film, an oxide thin film, a nitride thin film, an oxynitride thin film, and the like.
The process of forming the thin film may be performed under a condition in an in-chamber pressure range of 0.1 to 10 Torr. In addition, it is suitable that a source power for forming the plasma in the chamber is in the range of 500 to 9,000 W, and a bias power is in the range of 0 to 5,000 W. In addition, the bias power may not be applied in some cases.
In addition, the process of forming the thin film on the substrate is preferably performed in a temperature range of 150° C. to 500° C.
In addition, when feeding the precursor for forming the thin film, a second metal precursor may be introduced as needed to further improve the electrical properties, that is, to improve the capacitance or reduce leakage current values, of the finally formed metal film. As the second metal precursor, a metal precursor including one or more metals (M″) selected from magnesium (Mg), strontium (Sr), barium (Ba), lanthanide (Ln), titanium (Ti), zirconium (Zr), hafnium (Hf), niobium (Nb), tantalum (Ta), aluminum (Al), indium (In), silicon (Si), germanium (Ge), and tin (Sn) atoms may further optionally be fed. The second metal precursor may be an alkoxy-based compound or an alkylamide-based compound including the metal described above. For example, when the metal is Si, SiH(N(CH3)2)3, SiH2(N(C2H5)2)2, SiH2(NHtBu)2, SiH3 (N(iPr)2), Si(OC4H9)4, Si(OC2H5)4, Si(OCH3)4, Si(OC(CH3)3)4, and the like may be used as the second metal precursor.
The feeding of the second metal precursor may be performed in the same manner as the feeding of the precursor for forming the thin film. In addition, the second metal precursor may be fed onto the substrate for forming the thin film in conjunction with the precursor or may be fed sequentially after the precursor is completely fed.
The precursor for forming the thin film and, optionally, the second metal precursor described above are preferably kept in a temperature range of 50° C. to 250° C. and are more preferably kept in a temperature range of 100° C. to 200° C., before being fed into the reaction chamber, to be brought into contact with the substrate for forming the thin film.
In addition, after the step of feeding the precursor and before feeding the reactive gas, a purge process using an inert gas, such as argon (Ar), nitrogen (N2), or helium (He), in a reactor may be performed to help the precursor and, optionally, the second metal precursor move onto the substrate or allow for the internal pressure of the reactor suitable for deposition and also to remove impurities from the chamber to the outside. In this case, the purge process using the inert gas is preferably performed so that the internal pressure of the reactor is in the range of 1 to 5 Torr.
In addition, as the reactive gas, any one or a mixture of water vapor (H2O), oxygen (O2), ozone (O3), hydrogen peroxide (H2O2), hydrogen (H2), ammonia (NH3), nitric oxide (NO), nitrous oxide (N2O), nitrogen dioxide (NO2), hydrazine (N2H4), and silane (SiH4) may be used. When the thin film formation process is performed in the presence of oxidizing gases such as water vapor, oxygen, ozone, and the like described above, a metal oxide thin film may be formed. Alternatively, when the thin film formation process is performed in the presence of reducing gases such as hydrogen, ammonia, hydrazine, silane, and the like described above, a pure metal thin film or metal nitride thin film may be formed. In addition, a metal oxynitride thin film may be formed by the combination of the reactive gases.
Furthermore, a treatment process by heat treatment or light irradiation, in addition to plasma treatment, may be performed. This treatment process is intended to provide heat energy for the deposition of the precursor for forming the thin film and may be performed by methods known in the art. Preferably, to manufacture thin films having the desired physical state and composition at a sufficient growth rate, the treatment process above is preferably performed so that the temperature of the substrate in the reactor is in the range of 100° C. to 1,000° C. and is preferably in the range of 250° C. to 600° C.
In addition, even during the treatment process, a purge process using an inert gas, such as argon (Ar), nitrogen (N2), or helium (He), in a reactor may be performed to help the reactive gas move onto the substrate or allow for the internal pressure of the reactor suitable for deposition and also to remove impurities or byproducts from the reactor to the outside, as described above.
The treatment process involving the feeding of the precursor for forming the thin film, feeding of the inert gas, feeding of the reactive gas, and feeding of the inert gas, described above, is considered 1 cycle, and when repeatedly performing 1 or more cycles, the thin film can be formed.
In addition, with the application of the thin film formation process above, various semiconductor elements including the thin film may be manufactured.
The following examples will describe the effects of the present disclosure.
To a solution of 300 mL of THF and 48.22 g (0.512 mol) of ethylcyclopentadiene, 204.9 mL (0.512 mol) of an n-BuLi hexane solution (2.5 M) was slowly added dropwise at a temperature of −78° C. Subsequently, the resulting product was stirred for 30 minutes, heated to room temperature, and then stirred for an additional 2 hours, thereby preparing a Li-EtCp solution. To a new flask, 50.0 g (0.256 mol) of yttrium chloride and 150 mL of toluene were introduced, followed by cooling the resulting product to a temperature of −78° C. with stirring. The previously prepared Li-EtCp solution was slowly added dropwise to the flask containing the yttrium chloride mixture. Then, the resulting product was stirred at a temperature of −78° C. for 30 minutes, heated to room temperature, and stirred for 12 hours to synthesize bis(ethylcyclopentadienyl) yttrium chloride.
Into 300 mL of THF, 32.83 g (0.256 mol) of diethyl-ethylamidinate was introduced, followed by cooling the resulting product to a temperature of −78° C., and 102.4 mL (0.256 mol) of an n-BuLi hexane solution (2.5 M) was then slowly added dropwise to prepare Li-(Et2Et-AMD). The resulting solution was stirred at a temperature of −78° C. for 30 minutes, heated to room temperature, and then stirred for an additional 2 hours at room temperature. The prepared Li-(Et2Et-AMD) solution was slowly added dropwise to a flask containing (EtCp)2YCl at room temperature and then stirred at room temperature for 12 hours. The resulting mixture was evaporated under vacuum, dissolved in 250 mL of pentane, and filtered to evaporate the solvent and volatiles under vacuum to produce a red liquid, which was then used at a temperature of 165° C. and a pressure of 40 mTorr to obtain a pale yellow liquid. The yield was 60.1 g (58.3%). The analysis results of NMR (AV400 MHz HD, purchased from Bruker) are shown in FIG. 1.
1H NMR (C6D6, 25° C.): 0.85 (t, 3H), 0.98 (t, 6H), 1.20 (t, 6H), 1.97 (q, 2H), 2.48 (q, 4H), 2.97 (q, 4H), 6.0 (dt, 8H).
During TGA measurement (SDT Q600, purchased from TA instrument) performed at a temperature rise rate of 10° C./min in a nitrogen atmosphere at a flow rate of 200 mL/min, the pale yellow liquid had a residual mass of 0%, indicating that there were almost no residues left. These results are shown in
The pale yellow liquid sample was placed in a sealed container for DSC and kept under a temperature condition of 40° C. for 10 minutes, followed by observing a decomposition peak at a temperature of 431° C. during DSC analysis measurement (Discovery 25, purchased from TA instrument) performed at a temperature rise rate of 10° C./min. These results are shown in
Into 300 mL of THF, 36.43 g (0.256 mol) of diethyl-normal-propylamidinate was introduced, followed by cooling the resulting product to a temperature of −78° C., and 102.4 mL (0.256 mol) of an n-BuLi hexane solution (2.5 M) was then slowly added dropwise to prepare Li-(Et2nPr-AMD). The resulting solution was stirred at a temperature of −78° C. for 30 minutes, heated to room temperature, and then stirred for an additional 2 hours at room temperature. The prepared Li-(Et2nPr-AMD) solution was slowly added dropwise to a flask containing Y(EtCp)2Cl at room temperature and then stirred at room temperature for 12 hours. The resulting mixture was evaporated under vacuum, dissolved in 250 mL of pentane, and filtered to evaporate the solvent and volatiles under vacuum to produce a red liquid, which was then distilled at a temperature of 185° C. and a pressure of 40 mTorr to obtain a pale yellow liquid. The yield was 65.1 g (61.0%). The analysis results of NMR (AV400 MHz HD, purchased from Bruker) are shown in
1H NMR (C6D6, 25° C.): 0.83 (t, 3H), 0.99 (t, 6H), 1.20 (t, 6H), 1.36 (q, 2H), 1.98 (q, 2H), 2.50 (q, 4H), 3.00 (q, 4H), 6.0 (dt, 8H).
During TGA measurement (SDT Q600, purchased from TA instrument) performed at a temperature rise rate of 10° C./min in a nitrogen atmosphere at a flow rate of 200 mL/min, the pale yellow liquid had a residual mass of 0%, indicating that there were almost no residues left. These results are shown in
Into 300 mL of THF, 40.02 g (0.256 mol) of diethyl-normal-propylamidinate was introduced, followed by cooling the resulting product to a temperature of −78° C., and 102.4 mL (0.256 mol) of an n-BuLi hexane solution (2.5 M) was then slowly added dropwise to prepare Li-(nPr2Et-AMD). The resulting solution was stirred at a temperature of −78° C. for 30 minutes, heated to room temperature, and then stirred for an additional 2 hours at room temperature. The prepared Li-(nPr2Et-AMD) solution was slowly added dropwise to a flask containing Y(EtCp)2Cl at room temperature and then stirred at room temperature for 12 hours. The resulting mixture was evaporated under vacuum, dissolved in 250 mL of pentane, and filtered to evaporate the solvent and volatiles under vacuum to produce a red liquid, which was then distilled at a temperature of 185° C. and a pressure of 40 mTorr to obtain a yellow liquid. The yield was 63.7 g (57.8%). The analysis results of NMR (AV400 MHz HD, purchased from Bruker) are shown in
1H NMR (C6D6, 25° C.): 0.90 (m, 9H), 1.21 (t, 6H), 1.40 (q, 4H), 1.98 (q, 2H), 2.50 (q, 4H), 3.00 (q, 4H), 6.1 (dt, 8H).
During TGA measurement (SDT Q600, purchased from TA instrument) performed at a temperature rise rate of 10° C./min in a nitrogen atmosphere at a flow rate of 200 ml/min, the pale yellow liquid had a residual mass of 0%, indicating that there were almost no residues left. These results are shown in
To a solution of 300 mL of THF and 55.40 g (0.512 mol) of isopropylcyclopentadiene, 204.9 mL (0.512 mol) of an n-BuLi hexane solution (2.5 M) was slowly added dropwise at a temperature of −78° C. Subsequently, the resulting product was stirred for 30 minutes, heated to room temperature, and then stirred for an additional 2 hours, thereby preparing a Li-EtCp solution. Into a new flask, 50.0 g (0.256 mol) of yttrium chloride and 150 mL of toluene were introduced, followed by cooling the resulting product to a temperature of −78° C. with stirring. The previously prepared Li-EtCp solution was slowly added dropwise to the flask containing the yttrium chloride mixture. Then, the resulting product was stirred at a temperature of −78° C. for 30 minutes, heated to room temperature, and stirred for 12 hours to synthesize bis(isopropylcyclopentadienyl)yttrium chloride.
Into 300 mL of THF, 32.83 g (0.256 mol) of diethyl-ethylamidinate was introduced, followed by cooling the resulting product to a temperature of −78° C., and 102.4 mL (0.256 mol) of an n-BuLi hexane solution (2.5 M) was then slowly added dropwise to prepare Li-(Et2Et-AMD). The resulting solution was stirred at a temperature of −78° C. for 30 minutes, heated to room temperature, and then stirred for an additional 2 hours at room temperature. The prepared Li-(Et2Et-AMD) solution was slowly added dropwise to a flask containing (iPrCp)2YCl at room temperature and then stirred at room temperature for 12 hours. The resulting mixture was evaporated under vacuum, dissolved in 250 mL of pentane, and filtered to evaporate the solvent and volatiles under vacuum to produce a red liquid, which was then distilled at a temperature of 170° C. and a pressure of 20 mTorr to obtain a yellow liquid. The yield was 63.6 g (70.1%). The analysis results of NMR (AV400 MHz HD, purchased from Bruker) are shown in
1H NMR (C6D6, 25° C.): 0.85 (t, 3H), 1.02 (t, 6H), 1.24 (d, 12H), 1.94 (q, 2H), 2.82 (m, 2H), 3.01 (q, 4H), 6.01 (dt, 8H).
During TGA measurement (SDT Q600, purchased from TA instrument) performed at a temperature rise rate of 10° C./min in a nitrogen atmosphere at a flow rate of 200 mL/min, the pale yellow liquid had a residual mass of 0%, indicating that there were almost no residues left.
To a solution of 300 mL of THF and 33.85 g (0.512 mol) of cyclopentadiene, 204.9 mL (0.512 mol) of an n-BuLi hexane solution (2.5 M) was slowly added dropwise at a temperature of −78° C. Subsequently, the resulting product was stirred for 30 minutes, heated to room temperature, and then stirred for an additional 2 hours, thereby preparing a Li-Cp solution. Into a new flask, 50.0 g (0.256 mol) of yttrium chloride and 150 mL of toluene were introduced, followed by cooling the resulting product to a temperature of −78° C. with stirring. The previously prepared Li-Cp solution was slowly added dropwise to the flask containing the yttrium chloride mixture. Then, the resulting product was stirred at a temperature of −78° C. for 30 minutes, heated to room temperature, and stirred for 12 hours to synthesize bis(cyclopentadienyl)yttrium chloride.
Into 300 mL of THF, 32.83 g (0.256 mol) of diethyl-ethylamidinate was introduced, followed by cooling the resulting product to a temperature of −78° C., and 102.4 mL (0.256 mol) of an n-BuLi hexane solution (2.5 M) was then slowly added dropwise to prepare Li-(Et2Et-AMD). The resulting solution was stirred at a temperature of −78° C. for 30 minutes, heated to room temperature, and then stirred for an additional 2 hours at room temperature. The prepared Li-(Et2Et-AMD) solution was slowly added dropwise to a flask containing (Cp)2YCl at room temperature and then stirred at room temperature for 12 hours. The resulting mixture was evaporated under vacuum, dissolved in 250 mL of pentane, and filtered to evaporate the solvent and volatiles under vacuum to produce a red liquid, which was then used at a temperature of 166° C. and a pressure of 33 mTorr to obtain a yellow solid. The yield was 51.2 g (48.5%). The analysis results of NMR (AV400 MHz HD, purchased from Bruker) are shown in
1H NMR (C6D6, 25° C.): 0.81 (t, 3H), 0.96 (t, 6H), 1.90 (q, 2H), 2.96 (q, 4H), 6.16 (s, 8H).
During TGA measurement (SDT Q600, purchased from TA instrument) performed at a temperature rise rate of 10° C./min in a nitrogen atmosphere at a flow rate of 200 mL/min, the yellow solid had a residual mass of 1.5%, indicating that there were almost no residues left. These results are shown in
The yellow solid sample was placed in a sealed container for DSC and kept under a temperature condition of 40° C. for 10 minutes, followed by observing a decomposition peak at a temperature of 402° C. during DSC analysis measurement (Discovery 25, purchased from TA instrument) performed at a temperature rise rate of 10° C./min.
Into 300 mL of THF, 36.433 g (0.256 mol) of diethyl-normal-propylamidinate was introduced, followed by cooling the resulting product to a temperature of −78° C., and 102.4 mL (0.256 mol) of an n-BuLi hexane solution (2.5 M) was then slowly added dropwise to prepare Li-(Et2nPr-AMD). The resulting solution was stirred at a temperature of −78° C. for 30 minutes, heated to room temperature, and then stirred for an additional 2 hours at room temperature. The prepared Li-(Et2nPr-AMD) solution was slowly added dropwise to a flask containing (Cp)2YCl at room temperature and then stirred at room temperature for 12 hours. The resulting mixture was evaporated under vacuum, dissolved in 250 mL of pentane, and filtered to evaporate the solvent and volatiles under vacuum to produce a red liquid, which was then used at a temperature of 160° C. and a pressure of 28 mTorr to obtain a red solid. The yield was 49.6 g (53.8%). The analysis results of NMR (AV400 MHz HD, purchased from Bruker) are shown in
1H NMR (C6D6, 25° C.): 0.82 (t, 3H), 0.97 (t, 6H), 1.28 (t, 6H), 1.93 (q, 2H), 2.99 (q, 4H), 6.0 (s, 8H).
During TGA measurement (SDT Q600, purchased from TA instrument) performed at a temperature rise rate of 10° C./min in a nitrogen atmosphere at a flow rate of 200 ml/min, the red solid had a residual mass of 1.9%, indicating that there were almost no residues left. These results are shown in
Into 300 mL of THF, 32.83 g (0.256 mol) of di-normal-propyl-ethylamidinate was introduced, followed by cooling the resulting product to a temperature of −78° C., and 102.4 mL (0.256 mol) of an n-BuLi hexane solution (2.5 M) was then slowly added dropwise to prepare Li-(nPr2Et-AMD). The resulting solution was stirred at a temperature of −78° C. for 30 minutes, heated to room temperature, and then stirred for an additional 2 hours at room temperature. The prepared Li-(nPr2Et-AMD) solution was slowly added dropwise to a flask containing (Cp)2YCl at room temperature and then stirred at room temperature for 12 hours. The resulting mixture was evaporated under vacuum, dissolved in 250 mL of pentane, and filtered to evaporate the solvent and volatiles under vacuum to produce a red liquid, which was then used at a temperature of 165° C. and a pressure of 36 mTorr to obtain a yellow solid. The yield was 55.8 g (55.8%). The analysis results of NMR (AV400 MHz HD, purchased from Bruker) are shown in
1H NMR (C6D6, 25° C.): 0.84 (t, 3H), 0.89 (t, 6H), 1.44 (t, 4H), 1.91 (q, 2H), 3.03 (q, 4H), 6.16 (s, 8H).
During TGA measurement (SDT Q600, purchased from TA instrument) performed at a temperature rise rate of 10° C./min in a nitrogen atmosphere at a flow rate of 200 ml/min, the yellow solid had a residual mass of 2.3%, indicating that there were almost no residues left. These results are shown in
The yellow solid sample was placed in a sealed container for DSC and kept under a temperature condition of 40° C. for 10 minutes, followed by observing a decomposition peak at a temperature of 410° C. during DSC analysis measurement (Discovery 25, purchased from TA instrument) performed at a temperature rise rate of 10° C./min.
To a solution of 300 mL of THF and 41.04 g (0.512 mol) of methylcyclopentadiene, 204.9 mL (0.512 mol) of an n-BuLi hexane solution (2.5 M) was slowly added dropwise at a temperature of −78° C. Subsequently, the resulting product was stirred for 30 minutes, heated to room temperature, and then stirred for an additional 2 hours, thereby preparing a Li-MeCp solution. Into a new flask, 50.0 g (0.256 mol) of yttrium chloride and 150 mL of toluene were introduced, followed by cooling the resulting product to a temperature of −78° C. with stirring. The previously prepared Li-MeCp solution was slowly added dropwise to the flask containing the yttrium chloride mixture. Then, the resulting product was stirred at a temperature of −78° C. for 30 minutes, heated to room temperature, and stirred for 12 hours to synthesize bis(methylcyclopentadienyl) yttrium chloride.
Into 300 mL of THF, 32.83 g (0.256 mol) of diethyl-ethylamidinate was introduced, followed by cooling the resulting product to a temperature of −78° C., and 102.4 mL (0.256 mol) of an n-BuLi hexane solution (2.5 M) was then slowly added dropwise to prepare Li-(Et2Et-AMD). The resulting solution was stirred at a temperature of −78° C. for 30 minutes, heated to room temperature, and then stirred for an additional 2 hours at room temperature. The prepared Li-(Et2Et-AMD) solution was slowly added dropwise to a flask containing (MeCp)2YCl at room temperature and then stirred at room temperature for 12 hours. The resulting mixture was evaporated under vacuum, dissolved in 250 mL of pentane, and filtered to evaporate the solvent and volatiles under vacuum to produce a red liquid, which was then used at a temperature of 157° C. and a pressure of 62 mTorr to obtain a colorless solid. The yield was 60.1 g (58.3%). The analysis results of NMR (AV400 MHz HD, purchased from Bruker) are shown in
1H NMR (C6D6, 25° C.): 0.85 (t, 3H), 0.97 (t, 6H), 1.95 (q, 2H), 2.10 (s, 6H), 2.97 (q, 4H), 6.0 (dt, 8H).
During TGA measurement (SDT Q600, purchased from TA instrument) performed at a temperature rise rate of 10° C./min in a nitrogen atmosphere at a flow rate of 200 ml/min, the yellow liquid had a residual mass of 1.1%, indicating that there were almost no residues left. These results are shown in
The yellow solid sample was placed in a sealed container for DSC and kept under a temperature condition of 40° C. for 10 minutes, followed by observing a decomposition peak at a temperature of 400° C. during DSC analysis measurement (Discovery 25, purchased from TA instrument) performed at a temperature rise rate of 10° C./min.
Into 300 mL of THF, 36.43 g (0.256 mol) of diethyl-normal-propylamidinate was introduced, followed by cooling the resulting product to a temperature of −78° C., and 102.4 mL (0.256 mol) of an n-BuLi hexane solution (2.5 M) was then slowly added dropwise to prepare Li-(Et2nPr-AMD). The resulting solution was stirred at a temperature of −78° C. for 30 minutes, heated to room temperature, and then stirred for an additional 2 hours at room temperature. The prepared Li-(Et2nPr-AMD) solution was slowly added dropwise to a flask containing (MeCp)2YCl at room temperature and then stirred at room temperature for 12 hours. The resulting mixture was evaporated under vacuum, dissolved in 250 mL of pentane, and filtered to evaporate the solvent and volatiles under vacuum to produce a red liquid, which was then used at a temperature of 170° C. and a pressure of 67 mTorr to obtain a colorless liquid. The yield was 59.11 g (59.4%). The analysis results of NMR (AV400 MHz HD, purchased from Bruker) are shown in
1H NMR (C6D6, 25° C.): 0.83 (t, 3H), 0.98 (t, 6H), 1.34 (t, 2H), 1.96 (q, 2H), 2.11 (s, 6H), 2.97 (q, 4H), 6.0 (dt, 8H).
During TGA measurement (SDT Q600, purchased from TA instrument) performed at a temperature rise rate of 10° C./min in a nitrogen atmosphere at a flow rate of 200 mL/min, the colorless liquid had a residual mass of 0.9%, indicating that there were almost no residues left. These results are shown in
The colorless liquid sample was placed in a sealed container for DSC and kept under a temperature condition of 40° C. for 10 minutes, followed by observing a decomposition peak at a temperature of 410° C. during DSC analysis measurement (Discovery 25, purchased from TA instrument) performed at a temperature rise rate of 10° C./min.
Into 300 mL of THF, 40.02 g (0.256 mol) of di-normal-propyl-ethylamidinate was introduced, followed by cooling the resulting product to a temperature of −78° C., and 102.4 mL (0.256 mol) of an n-BuLi hexane solution (2.5 M) was then slowly added dropwise to prepare Li-(nPr2Et-AMD). The resulting solution was stirred at a temperature of −78° C. for 30 minutes, heated to room temperature, and then stirred for an additional 2 hours at room temperature. The prepared Li-(nPr2Et-AMD) solution was slowly added dropwise to a flask containing (MeCp)2YCl at room temperature and then stirred at room temperature for 12 hours. The resulting mixture was evaporated under vacuum, dissolved in 250 mL of pentane, and filtered to evaporate the solvent and volatiles under vacuum to produce a red liquid, which was then used at a temperature of 155° C. and a pressure of 113 mTorr to obtain a yellow liquid. The yield was 60.1 g (58.3%). The analysis results of NMR (AV400 MHz HD, purchased from Bruker) are shown in
1H NMR (C6D6, 25° C.): 0.87 (t, 9H), 1.37 (q, 4H), 2.01 (q, 2H), 2.12 (s, 6H), 2.96 (q, 4H), 6.0 (dt, 8H).
During TGA measurement (SDT Q600, purchased from TA instrument) performed at a temperature rise rate of 10° C./min in a nitrogen atmosphere at a flow rate of 200 ml/min, the yellow liquid had a residual mass of 1.6%, indicating that there were almost no residues left. These results are shown in
To a solution of 300 mL of THF and 66.09 g (0.661 mol) of ethylcyclopentadiene, 264.4 mL (0.661 mol) of an n-BuLi hexane solution (2.5 M) was slowly added dropwise at a temperature of −78° C. Subsequently, the resulting product was stirred for 30 minutes, heated to room temperature, and then stirred for an additional 2 hours, thereby preparing a Li-EtCp solution. Into a new flask, 50.0 g (0.330 mol) of scandium chloride and 150 mL of toluene were introduced, followed by cooling the resulting product to a temperature of −78° C. with stirring. The previously prepared Li-EtCp solution was slowly added dropwise to the flask containing the scandium chloride mixture. Then, the resulting product was stirred at a temperature of −78° C. for 30 minutes, heated to room temperature, and stirred for 12 hours to synthesize bis(ethylcyclopentadienyl) scandium chloride.
Into 300 mL of THF, 47.01 g (0.330 mol) of diethyl-normal-propylamidinate was introduced, followed by cooling the resulting product to a temperature of −78° C., and 132.2 mL (0.330 mol) of an n-BuLi hexane solution (2.5 M) was then slowly added dropwise to prepare Li-(Et2nPr-AMD). The resulting solution was stirred at a temperature of −78° C. for 30 minutes, heated to room temperature, and then stirred for an additional 2 hours at room temperature. The prepared Li-(Et2nPr-AMD) solution was slowly added dropwise to a flask containing (EtCp)2ScCl at room temperature and then stirred at room temperature for 12 hours. The resulting mixture was evaporated under vacuum, dissolved in 250 mL of pentane, and filtered to evaporate the solvent and volatiles under vacuum to produce a red liquid, which was then distilled at a temperature of 150° C. and a pressure of 28.4 mTorr to obtain a colorless liquid. The yield was 73.33 g (59.6%).
1H NMR (C6D6, 25° C.): 0.22 (t, 3H), 1.00 (t, 6H), 1.19 (t, 6H), 1.33 (q, 2H), 1.92 (q, 2H), 2.38 (q, 4H), 3.03 (q, 4H), 6.0 (dt, 8H).
During TGA measurement performed at a temperature rise rate of 10° C./min in a nitrogen atmosphere at a flow rate of 200 mL/min, the pale yellow liquid sample had a residual mass of 1.2%. These results are shown in
The analysis results of TGA measurement performed on some of the precursors according to Synthesis Examples 1 to 16 are shown in Table 1.
The analysis results of DSC measurement performed on some of the precursors according to Synthesis Examples 1 to 16 are shown in Table 2.
To confirm the viscosity of the precursors of Synthesis Examples 2 and 3, each sample was placed in a measurement container of a rotational viscometer (LVD2T, purchased from Brookfield) to measure viscosity using a spindle for low viscosity under a temperature condition of 25° C. The results thereof are shown in Table 3.
Using the above precursor, a thin film formation process was performed as follows.
Using the precursor of Synthesis Example 3 and O3 serving as an oxidant, film deposition evaluation was performed through an ALD process by a bubbler system. The film deposition evaluation was based on changes in thin film thickness as a function of the number of process cycles (number of cycles vs. thickness).
The precursor of Synthesis Example 3 was heated to the vaporization temperature, and argon (Ar) gas was then injected through a dip line to generate bubbles so that the vapor of the precursor compound being a gas was fed into a reaction chamber via a carrier gas.
To confirm changes in thin film thickness as a function of the number of process cycles by placing SiO2 and TiN substrates in the reaction chamber while maintaining a set temperature (in the range of 180° C. to 320° C.), the deposition evaluation was performed under the following conditions: the precursor (5 to 15 seconds)—purge (60 seconds)—the oxidant (5 to 15 seconds)—purge (30 seconds).
The purge process was performed using argon (Ar) gas at a flow rate of 700 sccm, and ozone (O3), serving as the reactive gas, was injected at a concentration of 220 g/m3. The precursor was heated to a temperature of 80° C. while injecting argon serving as the carrier gas at a flow rate of 200 sccm, and the number of process cycles performed was 50, 100, and 150. The results demonstrating changes in thin film thickness as a function of the number of deposition cycles by process temperatures (180° C., 220° C., 260° C., 275° C., and 320° C.) are shown in
From the results in
The deposition rates by temperature are as shown in Table 4.
In addition, to measure changes in thin film deposition rates (ALD window) as a function of process temperatures, the precursor, according to Synthesis Example 3, was heated to the vaporization temperature, and argon (Ar) gas was then injected through a dip line to generate bubbles so that the vapor of the precursor compound being a gas was fed into a reaction chamber via a carrier gas.
To confirm changes in thin film deposition rates as a function of process temperatures by placing SiO2 and TiN substrates in the reaction chamber while varying temperatures, the following processes were performed in an orderly manner: feeding of the precursor (10 seconds)—purge (60 seconds)—feeding of the oxidant (10 seconds)—purge (30 seconds). The purge process was performed using argon (Ar) gas at a flow rate of 700 sccm. Ozone (O3), serving as the reactive gas, was injected at a concentration of 220 g/m3. The precursor was heated to a temperature of 80° C. while injecting argon serving as the carrier gas at a flow rate of 200 sccm, and the number of process cycles was 50.
From the results in
In addition, to confirm thin film crystallinity by process temperatures, XRD analysis was performed on the Y2O3 thin films obtained on the SiO2 and TiN specimens by process temperatures through the above process evaluation. As a result, the crystallinity of the thin films was confirmed. The crystallinity was measured after the deposition process, and analysis was also performed on specimens obtained after heat treatment using rapid thermal annealing (RTA) under a N2 atmosphere condition at a temperature of 600° C. for 30 seconds. As a result of the analysis, the cubic-phase crystallinity of Y2O3 was confirmed in the thin films deposited under the temperature conditions of 300° C. or higher among the thin films obtained immediately after deposition. Furthermore, it was found that the cubic-phase crystallinity of Y2O3 was formed under all temperature conditions after the heat treatment. The analyzed XRD results are shown in
In addition, XPS depth profiles were analyzed to confirm the composition and impurities of the thin film. Through XPS analysis performed on the Y2O3 thin films deposited onto the SiO2 and TiN specimens at a temperature of 275° C., the composition and impurity content of the thin films were confirmed. Both contents of C and N impurities in the thin films were confirmed to be 0%, while in terms of the O/Y content ratio, the composition ratio was confirmed to be 1.22. The analyzed results of the XPS depth profiles are shown in
The present disclosure has been described above with reference to preferred embodiments but is not limited to these embodiments. Various modifications and changes may be made by those skilled in the art to which the present disclosure belongs without departing from the spirit of the present disclosure. Such modifications and changes should be construed as falling within the scope of the present disclosure and the appended claims.
| Number | Date | Country | Kind |
|---|---|---|---|
| 10-2022-0116994 | Sep 2022 | KR | national |
| Number | Date | Country | |
|---|---|---|---|
| Parent | PCT/KR2023/011551 | Aug 2023 | WO |
| Child | 18988922 | US |
