Precursor for forming a lanthanide metal-containing thin film, method for forming a lanthanide metal-containing thin film using the same, and semiconductor device including the lanthanide metal-containing thin film

Abstract

The present invention relates to a precursor for forming a lanthanide metal-containing thin film, which comprises a compound represented by Chemical Formula 1, a method for forming a lanthanide metal-containing thin film using the same, and a semiconductor device including the lanthanide metal-containing thin film. The precursor contains a lanthanide metal as a central metal atom and includes a cyclopentadienyl ligand that provides properties such as a low melting point and high volatility. Together with this, by including a novel amidinate ligand that provides properties such as high structural stability, low viscosity, high volatility, high heat resistance, and a solid state having a liquid state at room temperature or a low melting point, it exhibits physical properties suitable for use in a thin film forming process and can form a high-quality thin film.

Description

Technical Field

[0001] The present invention relates to a precursor for forming a lanthanide metal-containing thin film, a method for forming a lanthanide metal-containing thin film using the same, and a semiconductor device including the lanthanide metal-containing thin film. More specifically, the present invention relates to a precursor for forming a lanthanide metal-containing thin film that has a low viscosity, high heat resistance, and high volatility due to a chemical structure including an amidinate ligand, and thus can form a high-quality thin film, a thin film forming method using the same, and a semiconductor device including the thin film.

Background Art

[0002] With the improvement of integration due to the miniaturization of the line width of semiconductor devices, the space allowed for realizing the capacitor structure is limited in terms of the line width, but there are limitations in the manufacturing method of semiconductor devices for realizing the capacitor structure with existing silicone-based dielectrics. In addition, while high-k thin films are applied to replace silicone-based dielectrics, there is a problem that the leakage current due to the bandgap deteriorates significantly.

[0003] As one of the solutions to solve such problems, a technique for forming a high-quality thin film is required. For this purpose, it is necessary to optimize the precursor used for thin film formation.

[0004] Conventionally, as an example of a precursor optimization solution, various doping precursors that can improve the characteristics of dielectric constant and leakage current have been proposed. However, the precursor is generally in a solid state or a liquid state with low volatility, and there is a risk of causing various problems in the thin film formation evaporation process due to its particularly high viscosity. Therefore, it can be said that improving the physical properties of the precursor, such as high volatility and low viscosity characteristics, is a very important issue for optimizing the precursor for thin film formation.

[0005] For this purpose, various metal-containing precursors have been developed. For example, in Korean Patent Publication No. 10-2019-0008427, a lanthanide metal-containing precursor containing an aza-allyl ligand is known, and in Korean Patent Publication No. 10-2019-0094238, a lanthanide metal-containing precursor containing a cyclopentadienyl ligand is known.

[0006] Particularly, in the case of a complex compound containing a cyclopentadienyl group, it has a lower melting point and higher volatility compared to a compound containing β-diketonate or bis(trimethylsilyl)amide, so it has an advantage in being used as a precursor in the thin film forming process.

[0007] For these reasons, in known technologies such as Korean Registered Patent No. 10-1660052, Korean Patent Publication No. 10-2019-0109142, and Korean Patent Publication No. 10-2021-0084297, a chemical structure in which cyclopentadienyl and amidinate are bonded by ligands as a precursor containing a lanthanide metal is presented. The precursor to which such a ligand is bonded can improve the disadvantages of existing lanthanide metal precursors with low vapor pressure and high viscosity and is reported to be suitable for the thin film forming process.

Summary of the Invention

Problems to be Solved by the Invention

[0008] The present invention has been devised in view of the prior art as described above, and its object is to provide a novel lanthanide metal-containing precursor for thin film formation that can exhibit chemical properties suitable as a precursor for thin film formation.

[0009] Another object of the present invention is to provide a lanthanide metal-containing precursor for thin film formation that exhibits chemical properties of low viscosity, high heat resistance, and high volatility and is in a liquid state at room temperature or a solid state with a low melting point.

[0010] Another object of the present invention is to provide a method for forming a thin film using the above precursor.

[0011] Another object of the present invention is to provide a semiconductor device including the thin film.

Means for Solving the Problem

[0012] The precursor for forming a lanthanide metal-containing thin film of the present invention for achieving the above object is characterized by containing a compound represented by the following Chemical Formula 1.

Chemical Formula

[0013] Further, R2 may be a linear, branched or cyclic alkyl group or alkenyl group having 2 to 4 carbon atoms.

[0014] Further, R1 and R3 are each independently a linear, branched or cyclic alkyl group or alkenyl group having 2 to 5 carbon atoms, and R2 may be a linear, branched or cyclic alkyl group or alkenyl group having 2 to 4 carbon atoms.

[0015] Further, R1 and R3 may be methyl groups.

[0016] Further, R2 may be an isopropyl group.

[0017] Further, R1 and R3 may each independently be a linear alkyl group or alkenyl group having 1 to 5 carbon atoms.

[0018] Further, each of R1 and R3 is independently a linear alkyl group or alkenyl group having 1 to 5 carbon atoms, and R2 may be a linear alkyl group or alkenyl group having 1 to 4 carbon atoms.

[0019] Further, both R1 and R3 are the same and may be an alkyl group or an alkenyl group.

[0020] Further, all of R1 to R3 are the same and may be an alkyl group or an alkenyl group.

[0021] Further, the precursor for forming the lanthanide metal-containing thin film may have a viscosity of 100 cP or less, preferably 80 cP or less, and more preferably 60 cP or less.

[0022] Further, the precursor for forming the lanthanide metal-containing thin film may have a melting point of 100°C or less, preferably 80°C or less, and more preferably 60°C or less.

[0023] Further, the precursor for forming the thin film may further contain a solvent, and the solvent may be any one or more of saturated or unsaturated hydrocarbons, ketones, ethers, glymes, esters, tetrahydrofuran, and tertiary amines having 1 to C 16 and may be contained in an amount of 1 to 99% by weight based on the total weight of the precursor for forming the thin film.

[0024] The method for forming a lanthanide metal-containing thin film according to the present invention includes a step of forming a thin film on a substrate using the precursor for forming the thin film, and the step of forming a thin film on the substrate includes a step of depositing the precursor for forming the thin film on the surface of the substrate to form a precursor thin film, and a step of reacting the precursor thin film with a reactive gas.

[0025] Further, the step of forming the precursor thin film may include a step of vaporizing the precursor for forming the thin film and transferring it into the chamber.

[0026] Also, the vapor deposition can be performed by any one of a spin-on dielectric (SOD) process, a low temperature plasma (LTP) process, a chemical vapor deposition (CVD), a plasma enhanced chemical vapor deposition (PECVD), a high density plasma-chemical vapor deposition (HDPCVD) process, an atomic layer deposition (ALD) process, or a plasma-enhanced atomic layer deposition (PEALD) process.

[0027] Also, the step of forming a lanthanide metal-containing thin film on the substrate can include a step of supplying the thin film-forming precursor to the substrate and applying plasma to form a thin film.

[0028] Also, the semiconductor device of the present invention is characterized by including a thin film manufactured by the method for forming a lanthanide metal-containing thin film.

Advantages of the Invention

[0029] The precursor for forming a lanthanide metal-containing thin film according to the present invention contains a cyclopentadienyl and an amidinate ligand, so that it has excellent structural stability of the precursor compound, and exhibits characteristics of low viscosity, high volatility, high heat resistance, and a liquid state at room temperature or a solid state with a low melting point. Therefore, it shows physical properties suitable for use in the process of forming a lanthanide metal-containing thin film.

[0030] Also, a high-quality lanthanide metal-containing thin film can be formed using the precursor, and a semiconductor device including a lanthanide metal-containing thin film manufactured by the thin film forming method can be provided.

Brief Description of the Drawings

[0031]

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Mode for Carrying Out the Invention

[0032] Hereinafter, the present invention will be described in more detail. The terms and words used in this specification and the claims should not be construed as being limited to their ordinary or dictionary meanings, and in accordance with the principle that the inventor can appropriately define the concept of the terms in order to explain his invention in the best way, they should be construed in a meaning and concept consistent with the technical idea of the present invention.

[0033] The precursor for forming a lanthanide metal-containing thin film according to the present invention is characterized by containing a compound represented by the following Chemical Formula 1.

Chem.

[0034] The lanthanide metals are 15 elements including lanthanum (La) with atomic number 57 to lutetium (Lu) with atomic number 71, and may include lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), and lutetium (Lu).

[0035] In Chemical Formula 1, R1 and R3 that constitute the amidinate ligand may be the same or different, and can be configured in various forms depending on the intended effect of the precursor that can be provided through the present invention.

[0036] Also, R2 that constitutes the amidinate ligand in Chemical Formula 1 may be a hydrogen atom, or a linear, branched, or cyclic alkyl group or alkenyl group having 1 to 4 carbon atoms, and non-limiting examples include n-alkyl groups such as an ethyl group, a propyl group, and a butyl group.

[0037] The compound represented by Chemical Formula 1 is a precursor having a chemical structure containing an amidinate ligand with a lanthanide metal as a central metal atom, includes a cyclopentadienyl ligand that provides properties such as a low melting point and high volatility, and together with this, includes a novel amidinate ligand having a structure different from the conventional one, so that it is possible to add properties such as high structural stability, low viscosity, high volatility, high heat resistance, and a liquid state at room temperature or a solid state having a low melting point.

[0038] That is, the precursor for forming a lanthanide metal-containing thin film according to the present invention has a lanthanide metal as a central metal and contains different ligands that can contribute to improving the properties of the precursor, particularly a novel amidinate ligand that provides excellent effects such as structural stability, low viscosity, high volatility, high heat resistance, and a solid state with a room temperature liquid state or a low melting point. By including this ligand, the precursor exhibits physical properties suitable for use in the thin film forming process and can form a high-quality thin film.

[0039] The precursor for forming a thin film represented by Chemical Formula 1 can have various forms with different functional groups.

[0040] As one embodiment, R2 may be a linear, branched, or cyclic alkyl group or alkenyl group having 2 to 4 carbon atoms. When R2 is provided with 2 or more carbon atoms, compared with the case of C1, the asymmetry within the molecule increases, thereby reducing the intermolecular interference. As a result, the precursor containing the ligand is not only easily formed into a liquid state or a solid state having a low melting point but also can obtain the property of low viscosity.

[0041] Further, R1 and R3 are each independently a linear, branched, or cyclic alkyl group or alkenyl group having 2 to 5 carbon atoms, and R2 may be a linear, branched, or cyclic alkyl group or alkenyl group having 2 to 4 carbon atoms.

[0042] Also, in one example, R1 and R3 may be methyl groups, and R2 may be an isopropyl group.

[0043] Further, R1 and R3 may each independently be a linear alkyl group or alkenyl group having 1 to 5 carbon atoms.

[0044] A linear alkyl group or alkenyl group can obtain the effect of improving the volatility and vapor pressure by reducing the molecular weight through the structural minimization of the branched or cyclic ligand.

[0045] Therefore, in the ligand according to an embodiment of the present invention, each of R1 and R3 can be composed of a linear alkyl group or alkenyl group. In this case, since the vapor pressure of the precursor for thin film formation containing the ligand is improved, effects such as process ease during the thin film formation process using the precursor can be obtained.

[0046] In addition to the vapor pressure improvement effect, since the ligand in which each of R1 and R3 is composed of a linear alkyl group has a high degree of structural freedom of the ligand, an effect of improving the degree of freedom of the precursor to which the ligand is applied can be obtained. Due to such an effect, an effect of minimizing the interaction between precursors to create the liquefaction and low viscosity characteristics of the precursors is shown.

[0047] Therefore, in the amidinate ligand according to an embodiment of the present invention, in Chemical Formula 1, R1 and R3 can be composed of a linear alkyl group or alkenyl group. In this case, the vapor pressure of the precursor containing the ligand can be improved, and not only is it easy to form in a liquid state or a solid state having a low melting point through an improvement in the degree of freedom, but also the characteristics of low viscosity can be obtained together.

[0048] Further, each of R1 and R3 is independently a linear C1-C5 alkyl group or alkenyl group, and R2 may be a linear C1-C4 alkyl group or alkenyl group.

[0049] Also, R1 and R3 may both be the same and may be a linear, branched or cyclic C1-C5 alkyl group or alkenyl group.

[0050] Also, R1 to R3 may all be the same and may be a linear, branched or cyclic C1-C4 alkyl group or alkenyl group.

[0051] An exemplary structure of the precursor for thin film formation represented by Chemical Formula 1 is as follows. In the following structure, Ln represents a lanthanide metal and is 15 elements including lanthanum (La) with atomic number 57 to lutetium (Lu) with atomic number 71, and is selected from lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), promethium (Pm), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb), lutetium (Lu).

Chem.

[0052] In addition, the cyclopentadienyl ligand has a substituted structure, and by adjusting the molecular size, the viscosity and volatility of the precursor compound can be adjusted.

[0053] Here, the precursor for lanthanide metal-containing thin film formation may have a viscosity of 100 cp or less, preferably 80 cP or less, and more preferably 60 cP or less. Also, the melting point of the precursor for thin film formation may be 100 °C or less, preferably 80 °C or less, and more preferably 60 °C or less.

[0054] Through the chemical structure of such a precursor for thin film formation, a liquid precursor with low viscosity, high heat resistance, and high volatility can be obtained, and thus a high-quality thin film can be formed.

[0055] In addition, the precursor for thin film formation of the present invention may further contain a solvent for dissolving or diluting the precursor compound in consideration of the conditions and efficiency of the thin film formation process. As the solvent, any one of saturated or unsaturated hydrocarbons, ketones, ethers, glymes, esters, tetrahydrofuran, and tertiary amines having C1-C 16 or a mixture thereof can be used. The C1-C16 Examples of saturated or unsaturated hydrocarbons include pentane, cyclohexane, ethylcyclohexane, heptane, octane, toluene, etc., and examples of tertiary amines include dimethylethylamine and triethylamine.

[0056] In particular, depending on the chemical structure, the compound of the precursor for thin film formation can be in a solid state at room temperature. In this case, by including the solvent, the compound can be dissolved. That is, when the solvent is included, it is preferably contained in a solvent and content that can dissolve the precursor compound, and is included in an amount of 1 to 99% by weight based on the total weight of the precursor for thin film formation.

[0057] Since the precursor with or without the solvent can be vaporized, it can be supplied into the chamber in the form of a precursor gas. Therefore, when the type of the precursor compound for thin film formation exists in a liquid state at normal temperature and can be easily vaporized, the thin film formation process can be performed without a separate solvent.

[0058] In addition, the lanthanum group metal-containing thin film formation process can be carried out by any one of a spin-on dielectric (SOD) process, a low temperature plasma (LTP) process, a chemical vapor deposition (CVD), a plasma enhanced chemical vapor deposition (PECVD), a high density plasma-chemical vapor deposition (HDPCVD) process, an atomic layer deposition (ALD) process, or a plasma-enhanced atomic layer deposition (PEALD) process.

[0059] For example, when applying the HDP-CVD process, it can be carried out at high vacuum and high power compared to the atmospheric pressure chemical vapor deposition process (AP-CVD), the low pressure chemical vapor deposition process (LP-CVD), or the plasma enhanced chemical vapor deposition process (PE-CVD). Therefore, a thin film with a structurally dense and excellent mechanical property can be formed.

[0060] Therefore, the thin film forming method according to the present invention includes a step of forming a thin film on a substrate using the thin film forming precursor.

[0061] Specifically, the step of forming a lanthanide group-containing thin film on the substrate may include a step of depositing the thin film forming precursor on the surface of the substrate to form a precursor thin film, and a step of reacting the precursor thin film with a reactive gas.

[0062] Further, it may include a step of vaporizing the thin film forming precursor for deposition of the precursor and transferring it into the chamber.

[0063] Also, the step of forming a lanthanide group metal-containing thin film on the substrate may include a step of supplying the thin film forming precursor to the substrate and applying plasma in the presence of a reactive gas to form a thin film such as a metal, an oxide, a nitride, or an oxynitride.

[0064] The step of forming the thin film can be carried out under a pressure condition in the chamber of 1 to 10 Torr. Also, the source power for forming plasma in the chamber is preferably 500 to 9,000 W, and the bias power is preferably 0 to 5,000 W. Also, the bias power may not be applied depending on the case.

[0065] Also, the step of forming a thin film on the substrate is preferably carried out in a temperature range of 150 to 500 °C.

[0066] Also, when supplying the precursor for thin film formation, in order to further improve the electrical properties of the finally formed metal film, that is, the capacitance or leakage current value, a second metal precursor can be selectively introduced as needed. The second metal precursor can be a metal precursor containing one or more metals (M) selected from magnesium (Mg), strontium (Sr), barium (Ba), lanthanum group (Ln), titanium (Ti), zirconium (Zr), hafnium (Hf), niobium (Nb), tantalum (Ta), aluminum (Al), indium (In), silicon (Si), germanium (Ge), tin (Sn) atoms. The second metal precursor can be an alkylamide compound or an alkoxy compound containing the metal. As an example, when the metal is Si, SiH(N(CH3)2)3, SiH2(N(C2H5)2)2, SiH2(NH t Bu)2, SiH3(N( i Pr)2), Si(OC4H9)4, Si(OC2H5)4, Si(OCH3)4, Si(OC(CH3)3)4, etc. can be used.

[0067] The supply of the second metal precursor can be carried out in the same manner as the supply method of the precursor for thin film formation. The second metal precursor may be supplied onto the thin film formation substrate together with the precursor, or may be sequentially supplied after the supply of the precursor is completed.

[0068] The precursor for thin film formation and optionally the second metal precursor as described above are preferably maintained at a temperature of 50 to 250 °C, more preferably 100 to 200 °C, until they are supplied into the reaction chamber to contact the thin film formation substrate.

[0069] Also, prior to the supply of the reactive gas after the supply step of the precursor, to assist the movement of the precursor and optionally the second metal precursor onto the substrate, or to make the pressure inside the reactor suitable for vapor deposition, and to release impurities present in the chamber to the outside, a step of purging the reactor with an inert gas such as argon (Ar), nitrogen (N2), or helium (He) can be performed. At this time, the purging of the inert gas is preferably performed so that the pressure inside the reactor becomes 1 to 5 Torr.

[0070] Also, 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) can be used. When performed in the presence of oxidizing gases such as water vapor, oxygen, and ozone, a metal oxide thin film can be formed. When performed in the presence of reducing gases such as hydrogen, ammonia, hydrazine, and silane, a thin film of a metal or a metal nitride can be formed. Also, a metal oxynitride thin film can be formed by mixing reactive gases.

[0071] Also, in addition to plasma treatment, a treatment step by heat treatment or light irradiation can be performed, but it is for providing thermal energy for the vapor deposition of the precursor for thin film formation and can be performed by a normal method. Preferably, in order to manufacture a thin film having a desired physical state and composition at a sufficient growth rate, the treatment step is preferably performed so that the temperature of the substrate inside the reactor becomes 100 to 1,000 °C, preferably 250 to 600 °C.

[0072] Also, during the above processing steps, as described above, to assist the movement of the reactive gas onto the substrate or to make the pressure inside the reactor suitable for vapor deposition, and to release impurities or by-products present inside the reactor to the outside, a step of purging an inert gas such as argon (Ar), nitrogen (N2), or helium (He) into the reactor can be performed.

[0073] By repeating the above-described process steps of introducing the precursor for thin film formation, introducing the reactive gas, and introducing the inert gas one or more times as one cycle, a thin film can be formed.

[0074] Also, when the thin film formation process is applied, various semiconductor elements including the thin film can be manufactured.

[0075] Hereinafter, the effects of the precursor of the present invention will be described by way of examples.

[0076] Example 1: Synthesis of Bis(ethylcyclopentadienyl)(diethyl-ethylamidinato)lanthanum [(EtCp)2La(Et2Et-AMD)] 20.0 g (0.0815 mol) of LaCl₃ and 250 ml of THF were placed in a 1 L Schlenk flask A and stirred for 6 hours. Also, 150 ml of THF and 3.91 g (0.163 mol) of NaH were placed in a 100 ml Schlenk flask B, and 15.36 g (0.1631 mol) of ethylcyclopentadiene was slowly added dropwise at 0 °C and stirred at room temperature for 12 hours to prepare Na-EtCp. The thus-prepared Na-EtCp was added dropwise to Schlenk flask A at 0 °C and stirred at room temperature for 6 hours. In a 250 ml Schlenk flask C, THF and 10.46 g (0.0815 mol) of diethyl-ethylamidinato were placed, and 401.8 ml (1.00 mol) of an n-BuLi hexane solution (2.5 M) was slowly added dropwise at 0 °C and stirred at room temperature for 1 hour. The synthesized Li-(Et₂nPr-AMD) mixture solution was added dropwise to Schlenk flask A at 0 °C, stirred at room temperature for 6 hours, and then the solvent was removed under reduced pressure. The mixture thus obtained was extracted with 100 mL of toluene, filtered, and the solvent and volatile substances were evaporated under vacuum. The liquid remaining after evaporation was purified by distillation at 185 °C and 44 mTorr to obtain a pale yellow solid. The yield was 23.14 g (63.0%). 1 The results of ¹H NMR analysis are as shown in Figure 1, and the following characteristic peaks were obtained. 1 ¹H NMR (C₆D₆, 25 °C): 0.86 (t, 3H), 1.04 (t, 6H), 1.30 (broad, 6H), 1.89 (q, 2H), 2.62 (broad, 4H), 3.00 (q, 4H), 6.0 (broad, 8H)

[0077] The pale yellow solid was measured by TGA (SDT Q600 manufactured by TA Instruments) analysis at a heating rate of 10 °C / min in an atmosphere in which nitrogen was flowing at 200 ml / min. The T 1 / 2 value was 232.4 °C, and the residual mass was 1.2% at 350 °C, leaving almost nothing. Such results are shown in Figure 2, which is the TGA analysis result showing the percentage of weight loss due to temperature change.

[0078] Also, after placing a pale yellow solid sample in a sealed container for DSC and maintaining it at 40°C for 10 minutes, a decomposition peak was observed at 400°C during DSC (Discovery25 manufactured by TA Instruments) analysis measured at a temperature increase rate of 10°C / min. Such results are shown in Figure 3, which is the DSC analysis result indicating the change in thermal energy due to temperature change.

[0079] Example 2: Synthesis of Bis(isopropylcyclopentadienyl)(diethyl-n-propylamidinato)cerium [(iPrCp)2Ce(Et2nPr-AMD)] 6.13 g (0.256 mol) of NaH and 140 ml of THF were placed in a 500 ml Schlenk flask, and 11.54 g (0.081 mol) of diethyl-n-propylamidinato and 17.56 g (0.162 mol) of isopropylcyclopentadiene were slowly added dropwise at 0°C. The mixture was stirred at room temperature for 12 hours to produce a mixture solution of Na-EtCp and Na-(Et2Et-AMD). The Schlenk flask containing the reactants was cooled to -10°C, and 20 g (0.081 mol) of cerium chloride was slowly added. After stirring at room temperature for 12 hours, it was evaporated under vacuum. The resulting liquid was purified by distillation at 250°C and 50 mTorr to obtain a dark purple liquid. The yield was 29.5 g (73.4%).

[0080] The dark purple liquid had a T value of 247.4°C and a residual mass of 1.1% at 350°C, leaving almost nothing during TGA (SDT Q600 manufactured by TA Instruments) analysis measured at a temperature increase rate of 10°C / min in an atmosphere where nitrogen was flowing at 200 mL / min. Such results are shown in Figure 4, which is the TGA analysis result indicating the percentage of weight loss due to temperature change. It was confirmed that the target compound was synthesized through the TGA analysis results of volatilization with a single volatilization curve. 1 / 2

[0081] ​Also, after placing a dark purple liquid sample in a sealed container for DSC and maintaining it at 40 °C for 10 minutes, a decomposition peak was observed at 399 °C during DSC (Discovery 25 manufactured by TA Instruments) analysis measured at a temperature increase rate of 10 °C / min. Such results are shown in FIG. 5, which is the DSC analysis result indicating the change in thermal energy due to temperature change.

[0082] Example 3: Synthesis of Bis(ethylcyclopentadienyl)(diethyl-ethylamidinato)gadolinium [(EtCp)2Gd(Et2Et-AMD)] 6.13 g (0.256 mol) of NaH and 140 ml of THF were placed in a 500 ml Schlenk flask, and 11.54 g (0.081 mol) of diethyl-n-propylamidinato and 17.56 g (0.162 mol) of isopropylcyclopentadiene were slowly added dropwise at 0 °C. The mixture was stirred at room temperature for 12 hours to prepare a solution of Na-EtCp and Na-(Et2Et-AMD) mixture. The Schlenk flask containing the reactants was cooled to -10 °C, and 20 g (0.081 mol) of gadolinium chloride was slowly added. After stirring at room temperature for 12 hours, it was evaporated under vacuum. The obtained liquid was purified by distillation at 250 °C and 50 mTorr to obtain a pale yellow liquid. The yield was 29.5 g (73.4%).

[0083] The pale yellow liquid had a T 1 / 2 value of 224 °C and a residual mass of 2% at 350 °C during TGA (SDT Q600 manufactured by TA Instruments) analysis measured at a temperature increase rate of 10 °C / min in an atmosphere where nitrogen was flowing at 200 ml / min. Such results are shown in FIG. 6, which is the TGA analysis result indicating the percentage of weight loss due to temperature change. From the TGA analysis results of volatilization with a single volatilization curve, it was confirmed that the target compound was synthesized.

[0084] Also, after placing a pale yellow liquid sample in a sealed container for DSC and maintaining it at 40°C for 10 minutes, a decomposition peak was observed at 412°C during DSC (Discovery 25 manufactured by TA Instruments) analysis measured at a temperature increase rate of 10°C / min. Such results are shown in Figure 7 which is the DSC analysis result indicating the change in thermal energy due to temperature change.

[0085] Also, the pale yellow liquid was analyzed with a viscometer (DV2T viscometer manufactured by Brookfield Ametek) in a nitrogen atmosphere for viscosity measurement, and it was confirmed that the liquid showed a low viscosity of 31 cP at 25°C.

[0086] Example 4: Synthesis of Bis(ethylcyclopentadienyl)(diethyl-ethylamidinato)dysprosium [(EtCp)2Dy(Et2Et-AMD)]

[0087] 160 ml of THF, 9.54 g (0.0744 mol) of diethyl-ethylamidinato, and 14.29 g (0.1489 mol) of ethylcyclopentadiene were placed in a 500 ml Schlenk flask and cooled to 0°C. 89.33 ml (0.2233 mol) of an n-BuLi hexane solution (2.5 M) was slowly added dropwise to the cooled solution, and the mixture was stirred at room temperature for 1 hour to produce a mixture solution of Li-EtCp and Li-(Et2Et-AMD). The Schlenk flask containing the reactants was cooled to 0°C, and 20 g (0.0744 mol) of dysprosium chloride was added. After stirring at room temperature for 3 hours, the mixture was evaporated under vacuum, and the resulting pale green liquid was purified by distillation at 170°C and 58 mTorr to obtain a pale green liquid. The yield was 19.7 g (55.6%).

[0088] The pale green liquid was measured during TGA (SDT Q600 manufactured by TA Instruments) analysis at a temperature increase rate of 10°C / min in an atmosphere where nitrogen was flowing at 200 ml / min. 1 / 2The value was 225.8 °C, and the residual mass was 1.58% at 350 °C, leaving almost nothing. Such results are shown in Figure 8, which is the TGA analysis result indicating the percentage of weight loss due to temperature change. From the TGA analysis results of volatilization with one volatilization curve, it was confirmed that the target compound was synthesized.

[0089] Also, a pale green liquid sample was placed in a sealed container for DSC, maintained at 40 °C for 10 minutes, and then during the DSC (Discovery 25 manufactured by TA Instruments) analysis measured at a temperature increase rate of 10 °C / min, a decomposition peak was observed at 418 °C. Such results are shown in Figure 9, which is the DSC analysis result indicating the change in thermal energy due to temperature change.

[0090] Also, the pale green liquid was analyzed with a viscometer (DV2T viscometer manufactured by Brookfield Ametek) in a nitrogen atmosphere for viscosity measurement, and it was confirmed that it showed a low viscosity of 38 cP at 25 °C.

[0091] Example 5: Synthesis of Bis(ethylcyclopentadienyl)(diethyl-ethylamidinato)lutetium [(EtCp)2Lu(Et2Et-AMD)]

[0092] 160 ml of THF, 9.12 g (0.0711 mol) of diethyl-ethylamidinato, and 13.39 g (0.1422 mol) of ethylcyclopentadiene were placed in a 500 ml Schlenk flask and cooled to 0 °C. 85.31 ml (0.2133 mol) of an n-BuLi hexane solution (2.5 M) was slowly added dropwise to the cooled solution, and the mixture was stirred at room temperature for one hour to produce a mixture solution of Li-EtCp and Li-(Et2Et-AMD). The Schlenk flask containing the reactants was cooled to 0 °C, and 20 g (0.0711 mol) of lutetium chloride was added. After stirring at room temperature for 3 hours, it was evaporated under vacuum, and the resulting brown liquid was purified by distillation at 170 °C and 55 mTorr to obtain an orange liquid. The yield was 22.4 g (64.5%). 1 The 1H NMR analysis results are as shown in Figure 10, and the following characteristic peaks were obtained. 11H NMR (C6D6, 25 °C): 0.83 (t, 3H), 0.98 (t, 6H), 1.19 (q, 6H), 1.93 (q, 2H), 2.44 (q, 4H), 3.00 (q, 4H), 6.0 (broad, 8H)

[0093] Also, the orange liquid was measured by TGA (SDT Q600 manufactured by TA Instruments) at a temperature increase rate of 10 °C / min in an atmosphere where nitrogen was flowing at 200 ml / min during 1 / 2 the T value was 223 °C, and the residual mass was 1.4% at 350. °C, leaving almost nothing. These results are shown in FIG. 11, which is the TGA analysis result showing the percentage of weight loss due to temperature change.

[0094] Also, after placing the orange liquid sample in a sealed container for DSC and maintaining it at 40 °C for 10 minutes, a decomposition peak was observed at 455 °C during DSC (Discovery25 manufactured by TA Instruments) analysis measured at a temperature increase rate of 10 °C / min. Such results are shown in FIG. 12, which is the DSC analysis result showing the change in thermal energy due to temperature change.

[0095] Also, the orange liquid was analyzed with a viscometer (DV2T viscometer manufactured by Brookfield Ametek) in a nitrogen atmosphere for viscosity measurement, and it was confirmed that it showed a low viscosity of 38 cP at 25 °C.

[0096] Production Example 1: Thin Film Formation Step Using the Precursor Compound of Example 3 An atomic layer deposition process was performed in a bubbler method using the precursor compound of Example 3 and O3 as an oxidant, and film formation evaluation was carried out. The film formation evaluation was based on the change in thin film thickness according to the process cycle (Number of cycles vs. Thickness). After raising the temperature of the precursor compound of Example 3 to the vaporization temperature, argon (Ar) gas was injected through a Dip line to generate bubbles, and the vapor of the precursor compound in the gaseous state was supplied into the reaction chamber using a carrier gas.

[0097] An SiO2 substrate and a TiN substrate were provided in the reaction chamber. In order to confirm the change in the thin film thickness by the process cycle while maintaining the set temperature (300 °C), the deposition evaluation was carried out while changing the conditions of the precursor supply time, purge time, oxidant supply time, and purge time. The purge process was carried out at a flow rate of 700 sccm of argon (Ar) gas, and ozone (O3), which is a reaction gas, was injected at a concentration of 220 g / m 3 . The precursor was heated at 100 °C and flowed at an argon carrier gas injection rate of 200 sccm. The saturation condition with respect to the precursor supply time was confirmed under the deposition conditions of 300 °C, and the results are shown in Fig. 13.

[0098] From the results in Fig. 13, it was confirmed that the precursor supply time was saturated from 14 seconds under the said process conditions.

[0099] Also, in order to confirm the change in the thin film thickness according to the number of process cycles, the number of cycles was set to 50, 100, 150, and 200 cycles. The results regarding the change in the thin film thickness according to the number of cycles are shown in Fig. 14.

[0100] From the results in Fig. 14, a constant change in the thin film thickness according to the number of deposition cycles was confirmed for the SiO2 specimens evaluated, and the GPC (growth per cycle) was confirmed to be approximately 0.079 nm / cycle.

[0101] Also, in order to measure the change in the thin film deposition rate (ALD window) according to the process temperature, after raising the temperature of the precursor according to Example 3 to the vaporization temperature, argon (Ar) gas was injected through the Dip line to generate bubbles, and the vapor of the precursor compound in the gaseous state was supplied into the reaction chamber through the carrier gas.

[0102] SiO2 and TiN substrates were placed in the reaction chamber, and in order to confirm the change in the thin film deposition rate according to the process temperature (250, 280, 300, 320, 350 °C) while changing the temperature, the precursor (14 seconds) - purge (140 seconds) - oxidant (10 seconds) - purge (30 seconds) were supplied in this order. The purge process was carried out at a flow rate of 700 sccm of argon (Ar) gas. Ozone (O3), which is a reaction gas, was injected at a concentration of 220 g / m 3 . The precursor was heated to 100 °C and flowed at an argon carrier gas injection rate of 200 sccm, and the number of process cycles was 50 cycles. The results of the change in the thin film deposition rate according to the process temperature are shown in Figure 15.

[0103] From the results in Figure 15, it can be seen that similar thin film deposition rates of about 0.09 nm / cycle were shown at process temperatures (250 °C, 280 °C, 300 °C), and thus it has a process temperature range (ALD window) with the same thin film thickness. And under the conditions of 320 °C and 350 °C, a tendency for the GPC to slightly decrease was confirmed.

[0104] In addition, in order to confirm the thin film crystallinity for each process temperature, XRD analysis was performed on the Gd2O3 thin films obtained for each process temperature through the above process evaluation using SiO2 and TiN specimens to confirm the crystallinity of the thin films. The crystallinity was measured after the deposition processes at 300 °C and 320 °C, and analysis was also performed on the specimens after heat treatment at 600 °C for 60 seconds under N2 conditions using RTA. As a result of the analysis, the diffraction patterns measured regardless of the type of substrate confirmed the Gd2O3 crystallinity in which monoclinic and cubic crystallinities were mixed. It was confirmed that crystallization was promoted in the cubic phase under the condition of 320 °C compared to 300 °C. The change in crystallinity due to heat treatment was not large, but it was confirmed that the crystallinity slightly improved after heat treatment of the 320 °C deposition sample. The analyzed XRD results are shown in Figure 16.

[0105] In addition, XPS depth profile analysis was performed to confirm the composition and impurities of the thin film. For the Gd2O3 thin film deposited on the TiN substrate at 300 °C, the composition and impurity content of the thin film were confirmed through XPS analysis. All C and N impurities in the thin film were confirmed to be 0%. The ratio of the O / Gd content was about 2.5, confirming that it had an oxygen-rich composition ratio. The analyzed XPS depth profile results are shown in Fig. 17.

[0106] In addition, to evaluate the electrical properties of the thin film, a MIM (Metal Insulator Metal) structure was fabricated as shown in Fig. 18, where a Gd2O3 thin film was deposited on a TiN substrate at a thickness of 10 nm at 300 °C and 320 °C, and TiN was deposited as the upper electrode.

[0107] The results of confirming the dielectric constant and leakage current characteristics of the Gd2O3 thin film in the fabricated device are as shown in Table 1.

Table 1

[0108] From the above results, it was confirmed that the fabricated thin film can be utilized as a thin film capable of improving the characteristics of the dielectric film.

[0109] Production Example 2: Thin Film Formation Process Using the Precursor Compound of Example 2 Using the precursor of Example 2 and O3 as the oxidant, film formation evaluation was carried out by the atomic layer deposition process in a bubbler method.

[0110] A SiO2 substrate and a TiN substrate were provided in the reaction chamber. To confirm the change in the thin film thickness by the process cycle while maintaining the set temperature (280 °C), deposition evaluation was carried out under the conditions of precursor (40 s) - purge (80 s) - oxidant (15 s) - purge (30 s). The purge process was carried out at a flow rate of 700 sccm of argon (Ar) gas, and the reaction gas ozone (O3) was 200 g / m 3It was injected at the concentration of. The precursor was heated at 110 °C, flowed with an argon carrier gas injection amount of 200 sccm, and after setting the temperature of the gas transfer pipe to 120 °C, a Ce-containing thin film was formed with the number of process cycles being 100 cycles.

[0111] In the case of the formed thin film, the GPC was 0.088 nm / cycle, and the density of the formed thin film was 4.74 g / cm 3 and it was confirmed that the roughness was 0.7 nm, which was good. The analysis results are shown in Fig. 19.

[0112] Also, as a result of analyzing the crystallinity to confirm the characteristics of the thin film as a high dielectric thin film, it was confirmed that regardless of the substrate conditions, it exhibited the crystallinity of the cubic phase, and it was confirmed that it exhibited the crystallinity of the cubic phase with a thickness of 4 nm. The analysis results are shown in Fig. 20.

[0113] From such results, it was confirmed that the manufactured thin film can be utilized as a thin film capable of improving the characteristics of the dielectric film.

[0114] Although the present invention has been described by giving preferred embodiments as described above, it is not limited to the above embodiments, and various modifications and changes can be made by those having ordinary knowledge in the technical field to which the present invention pertains without departing from the spirit of the present invention. Those modified examples and changed examples should also be regarded as belonging to the scope of the present invention and the appended claims.

Claims

1. A precursor for forming a lanthanide metal-containing thin film, characterized by containing a lanthanide metal-containing compound represented by the following Chemical Formula 1. 【Chemical Formula 1】 (In the formula, M is a lanthanide metal, and R １ and R ３ are each independently a linear, branched or cyclic alkyl or alkenyl group of C １ -C ５ , R ２ is a hydrogen atom or a linear, branched or cyclic alkyl or alkenyl group of C １ -C ４ , R' may be the same as or different from each other and is a hydrogen atom or a linear, branched or cyclic alkyl or alkenyl group of C １ -C ４ , and n is an integer of 1 to 5.)

2. The R in the chemical formula 1 ２ is ２ -C ４ a linear, branched or cyclic alkyl group or alkenyl group, and the precursor for forming a lanthanide metal-containing thin film according to claim 1 is characterized in that.

3. In the formula (1), the R １ and R ３ are each independently a linear, branched or cyclic alkyl group or alkenyl group of C ２ -C ５ , and the R ２ is a linear, branched or cyclic alkyl group or alkenyl group of C ２ -C ４ The precursor for forming a lanthanide metal-containing thin film according to claim 1, characterized in that it is.

4. The R in the chemical formula 1 １ and R ３ are methyl groups, and the precursor for forming a lanthanide metal-containing thin film according to claim 1 is characterized thereby.

5. The R in the chemical formula 1 ２ is an isopropyl group, and the precursor for forming a lanthanide metal-containing thin film according to claim 1, characterized in that.

6. The R in the chemical formula 1 １ and R ３ are each independently a linear alkyl group or alkenyl group of C １ -C ５ The precursor for forming a lanthanide metal-containing thin film according to claim 1, characterized in that it is a linear alkyl group or alkenyl group of

7. In the formula (1), the R １ and R ３ are each independently a linear alkyl group or alkenyl group of C １ -C ５ , and the R ２ is a linear alkyl group or alkenyl group of C １ -C ４ . The precursor for forming a lanthanide metal-containing thin film according to claim 1, characterized in that it is as described above.

8. The R in the chemical formula 1 １ and R ３ are both the same and are a linear, branched or cyclic alkyl group or alkenyl group of C １ -C ５ The precursor for forming a lanthanide group metal-containing thin film according to claim 1, characterized in that it is.

9. The R in the chemical formula 1 １ to R ３ are all the same and are a linear, branched or cyclic alkyl group or alkenyl group of C １ -C ４ The precursor for forming a lanthanide group metal-containing thin film according to claim 1, characterized in that it is such.

10. The precursor for forming a lanthanide metal-containing thin film according to Claim 1, characterized in that the viscosity is 100 cP or less.

11. The precursor for forming a lanthanide metal-containing thin film according to Claim 1, characterized in that the melting point is 100°C or less.

12. The precursor for forming a thin film according to Claim 1, further characterized by containing a solvent.

13. The solvent is C １ -C １６ The precursor for forming a lanthanide group metal-containing thin film according to claim 12, characterized in that it is one or more of a saturated or unsaturated hydrocarbon, ketone, ether, glyme, ester, tetrahydrofuran, and tertiary amine of

14. The precursor for forming a lanthanide metal-containing thin film according to Claim 12, characterized in that the solvent is contained in an amount of 1 to 99% by weight based on the total weight of the precursor for forming a thin film.

15. The precursor for forming a thin film according to Claim 1, characterized in that it is at least one selected from the group consisting of the following structures. 【Chemical 2】 【Chem.】

16. A method for forming a lanthanide metal-containing thin film, characterized by including a step of forming a thin film on a substrate using the precursor for forming a thin film according to Claim 1 or 12.

17. The step of forming a thin film on the substrate includes: a step of depositing the precursor for forming a thin film on the surface of the substrate to form a precursor thin film; and a step of reacting the precursor thin film with a reactive gas. The method for forming a lanthanide metal-containing thin film according to Claim 16 is characterized by including these steps.

18. The step of forming the precursor thin film according to Claim 17 is characterized by including a step of vaporizing the precursor for forming a thin film and transferring it into the chamber.

19. The vapor deposition is performed by any one of a spin-on dielectric (SOD) process, a low temperature plasma (LTP) process, a chemical vapor deposition (CVD), a plasma enhanced chemical vapor deposition (PECVD), a high density plasma-chemical vapor deposition (HDP-CVD) process, an atomic layer deposition (ALD) process, or a plasma-enhanced atomic layer deposition (PEALD) process. The method for forming a lanthanide metal-containing thin film according to claim 17, characterized in that it is performed by any one of the above processes.

20. The step of forming a thin film on the substrate is The method for forming a lanthanide metal-containing thin film according to claim 16, characterized in that it includes a step of supplying the precursor for thin film formation to the substrate and applying plasma to form a thin film.

21. A semiconductor device, characterized in that it includes a lanthanide metal-containing thin film manufactured by the thin film formation method according to claim 16.

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