Method for forming a dielectric film, novel precursors and their use in semiconductor manufacturing

Abstract

A metal-containing film-forming composition comprising a precursor having the formula: M(=NR 1 )(OR 2 )(OR 3 ) m L. Wherein, M = V or Nb or Ta; R 1 -R 3 = independently, H or a C1-C10 alkyl group; L = a substituted or unsubstituted cyclopentadiene, cyclohexadiene, cycloheptadiene, cyclooctadiene, fluorene, indene, fused ring system, propylene, butadiene, pentadiene, hexadiene, heptadiene; m = 0 or 1.

Description

[0001] The present invention relates to a metal-containing film-forming composition comprising a precursor of niobium or vanadium, and a method for forming a niobium (Nb)- or vanadium-containing film on one or more substrates by a chemical vapor deposition process using the niobium- and vanadium-containing film-forming composition.

[0002] Metal oxide films, such as niobium oxide (Nb2O5), have been widely used in a number of technical fields. Traditionally, these oxides have been applied as resistive films, which serve as high-k materials for insulating layers. For example, a thin layer of Nb2O5 between two ZrO2 dielectric layers is expected to contribute to a significant reduction in leakage current and stabilization of the cubic / tetragonal phase of ZrO2, thus providing a higher k-value in current DRAM MIM capacitors (Alumina, J. Vac. Sci. Technol [Journal of Vacuum Science and Technology] A4(6), 1986 and Microelectronic Engineering [Microelectronic Engineering] 86(2009)1789 - 1795). A thin layer of V2O5 can have a similar performance.

[0003] Metal nitride films, such as niobium nitride, vanadium nitride (NbN x , VN x , where x is about 1) have been widely used in a number of technical fields. Traditionally, these nitrides have been applied as hard and decorative coatings, but in the past decade, they have increasingly been used as diffusion barriers and adhesion / glue layers in microelectronic devices [Applied Surface Science [Applied Surface Science] 120(1997)199 - 212].

[0004] Nb-containing mixed oxides have also received significant attention in energy storage applications, such as thin, highly ion-conductive interfacial layers between cathode active materials and electrolytes in all-solid-state batteries and lithium (Li)-ion batteries [US 7993782B2]. For example, it has been reported that a thin layer of lithium niobate deposited on a cathode active material in an appropriate crystalline phase reduces reaction resistance and increases battery power output [US2020 / 0075956A1]. Lithium niobate has received particular attention as an interfacial layer because it exhibits significantly higher ionic conductivity [Electrochem. Commun. [Electrochemical Communications] 2007, 9, 1486 - 1490]. Chemical vapor deposition (such as atomic layer deposition) has been reported to be a viable technique for depositing such a stable interfacial layer on low-cobalt cathode materials [ACS Appl. Mater. Interfaces [ACS Applied Materials & Interfaces] 2018, 10, 1654 - 1661].

[0005] For example, NbCl5 has been examined as a niobium source for NbN xAtomic layer epitaxial growth, but this process requires Zn as a reducing agent [Applied Surface Science 82 / 83 (1994) 468 - 474]. NbN has also been deposited by atomic layer deposition using NbCl5 and NH3 x films [Thin Solid Films 491 (2005) 235 - 241]. The chlorine content shows strong temperature dependence, as the film deposited at 500 °C contains almost no chlorine, while the chlorine content is 8% when the deposition temperature is as low as 250 °C. The high melting point of NbCl5 also makes it difficult to use this precursor in a vapor deposition process.

[0006] As an example for VN x V(NMe2)4 has been examined as a vanadium source for the chemical vapor deposition of VN x [Fix et al., Chemical Vapor Deposition of Vanadium, Niobium, and Tantalum Nitride Thin Films, Chem. Mater. 1993, 5, 614 - 619]. VN films have also been deposited using V(NEtMe)4 and NH3 by plasma - enhanced atomic layer deposition x [Rampelberg et al., Low Temperature Plasma - Enhanced Atomic Layer Deposition of Thin Vanadium Nitride Layers for Copper Diffusion Barriers, Appl. Phys. Lett., 102, 111910 (2013)].

[0007] Gust et al. disclosed the synthesis, structure, and properties of complexes of imido - niobium and imido - tantalum with pyrazole ligands and their potential use for the growth of tantalum nitride films by CVD (Polyhedron 20 (2001) 805 - 813).

[0008] Elorriaga et al. disclosed an asymmetric guanidino - niobium as an intermediate in the catalytic guanidination of amines (Dalton Transactions, 2013, Vol. 42, No. 23, pp. 8223 - 8230).

[0009] Tomson et al. disclosed the synthesis and reactivity of cationic Nb and Ta monomethyl complexes [(BDI)MeM(NtBu)][X] (BDI = 2,6-iPr2C6H3-N-C(Me)CH-C(Me)-N(2,6-iPr2C6H3); X = MeB(C6F5)3 or B(C6F5)4) (Dalton Transactions, 2011, Vol. 40, No. 30, pp. 7718-7729).

[0010] DE 102006037955 discloses tantalum - compounds and niobium - compounds of the formula R 4 R 5 R 6 M(R 1 NNR 2 R 3 )2, where M is Ta or Nb; R 1 -R 3 =C 1-12 alkyl, C 5-12 cycloalkyl, C 6-10 aryl, alkenyl, C 1-4 triorganosilyl; and R 4 -R 6 = halogen, (cyclo)alkoxy, aryloxy, silyloxy, BH4, allyl, indenyl, benzyl, cyclopentadienyl, CH2SiMe3, silylamino, amino, or imino.

[0011] Maestre et al. disclosed the reaction of cyclopentadienyl - silyl - amino titanium compounds with Group 5 metal monocyclopentadienyl complexes to form NbCp(NH(CH2)2 - NH2)CI3 and NbCpCI2(N-(CH2)2 - N).

[0012] Gibson et al. disclosed ligand - exchange reactions and kinetic studies of Mo complexes, Nb complexes (including Nb(=NtBu)Cp(OiPr)2, Nb(=NtBu)Cp(OtBu)2) (Dalton Transactions (2003), (23), 4457 - 4465).

[0013] Nowadays, there is a need to provide liquid or low - melting - point (at standard pressure < 50 °C), highly thermally stable precursor molecules containing niobium and vanadium, suitable for vapor - phase film deposition at high temperatures with controlled thickness and composition.

[0014] According to the present invention, precursors have been found that are suitable for depositing thin films containing Nb and V by the ALD process and have the following advantages:

[0015] · They are liquid at room temperature or have a melting point below 50 °C.

[0016] · They are thermally stable and enable proper distribution (vapor phase or direct liquid injection) without generating particles.

[0017] · They are thermally stable, enabling a wide self-limiting ALD window, and making it possible to deposit various films containing Nb and V by using one co-reactant or a combination of co-reactants. The co-reactant can typically be selected from oxidants (such as O2, O3, H2O, H2O2), alcohols, or nitriding agents (such as ammonia, amines, polyamines, hydrazine, NO). Such co-reactants can be plasma-activated or not.

[0018] They can also be used in combination with other precursors to deposit hybrid films. More particularly, these precursors are suitable for use with precursors of Group IV and other Group V elements, as well as with phosphorus compounds or lithium compounds, for example, for energy storage applications.

[0019] According to a first embodiment, the present invention relates to a metal-containing film-forming composition comprising a precursor having the following formula:

[0020] M(=NR 1 )(OR 2 )(OR 3 ) m L

[0021] wherein M = V or Nb or Ta; R 1 -R 3 = independently, H or a C1-C10 alkyl group;

[0022] L = substituted or unsubstituted cyclopentadiene, cyclohexadiene, cycloheptadiene, cyclooctadiene, fluorene, indene, polycyclic system, propene, butadiene, pentadiene, hexadiene, heptadiene; m = 0 or 1.

[0023] According to another particular embodiment, the present invention relates to:

[0024] · A metal-containing film-forming composition as defined above, wherein R 1 is H, R 2 is tBu; R 3 and R 4 are Et.

[0025] · A metal-containing film-forming composition as defined above, wherein R 1 is H, R 2 、R 3 and R 4 are tBu.

[0026] · A metal-containing film-forming composition as defined above, wherein R 1 is H, R 2 is tBu; R 3 and R 4 are sBu.

[0027] · A metal-containing film-forming composition as defined above, wherein M is vanadium.

[0028] · A metal-containing film-forming composition as defined above, wherein M is niobium.

[0029] · A metal-containing film-forming composition having the following formula:

[0030]

[0031] wherein each R 4 is H or a C1-C10 alkyl group or a fluorine group; n ≤ 5.

[0032] · A metal-containing film-forming composition having the following formula:

[0033]

[0034] wherein R 4 to R 10 are each independently H or a C1-C10 alkyl group or a fluorine group.

[0035] · A metal-containing film-forming composition having the following formula:

[0036]

[0037] wherein R 4 to R 6 are each independently H or a C1-C10 alkyl group, or a fluorine group.

[0038] · A metal-containing film-forming composition having the following formula:

[0039]

[0040] wherein R 4 to R 6 are each independently H or a C1-C10 alkyl group, or a fluorine group.

[0041] · A method for forming a metal-containing film, the method comprising introducing a vapor of a metal-containing film-forming composition as defined above into a reactor having a substrate therein; and depositing at least a portion of the precursor on the substrate.

[0042] · The method as defined above, further comprising introducing a reactant into the reactor.

[0043] · A method as defined above, wherein the reactant is selected from the group consisting of: O2, O3, H2O, H2O2, NO, N2O, NO2, TMPO, its oxygen free radicals, and mixtures thereof.

[0044] · A method as defined above, wherein M = Nb, and the niobium-containing film-forming composition and the reactant are introduced into the chamber in sequence, and the reactor is configured for atomic layer deposition.

[0045] · A method as defined above, wherein the substrate is a cathode active material powder.

[0046] · A method as defined above, wherein the substrate is a cathode material, and the cathode material consists of a cathode active material powder, conductive carbon, and a binder material deposited on a current collector foil.

[0047] · A method as defined above, wherein the substrate is ZrO2, and the niobium-containing film-forming composition is used to form a DRAM capacitor.

[0048] · The method further includes plasma treating the reactant.

[0049] · According to another embodiment, the present invention relates to a method for manufacturing a thin interfacial layer in a lithium-ion battery or all-solid-state battery device. The thin layer is formed using the Nb precursor of the present invention having the following formula:

[0050] Nb(=NR 1 )(OR 2 )(OR 3 ) m L

[0051] R 1 -R 3 = independently, H or a C1-C10 alkyl group;

[0052] L = a substituted or unsubstituted cyclopentadiene, cyclohexadiene, cycloheptadiene, cyclooctadiene, fluorene, indene, polycyclic system, propene, butadiene, pentadiene, hexadiene, heptadiene; m = 0 or 1; and a co-reactant, which is deposited in powder form on the cathode active material or on the niobium-containing oxide layer on the cathode by atomic layer deposition. The co-reactant can be selected from the list consisting of: O2, O3, H2O, H2O2, NO, NO2, H2O or NOx, trimethyl phosphate, diethyl aminophosphate, sulfate or any other oxygen-containing substance. The thin layer can be a ternary or quaternary niobium oxide, such as LiNbO, LiNb(M)O, NbMO, where M is selected from the list consisting of: Zr, Ti, Co, W, Ta, V, Sr, Ba, La, Y, Sc, Mn, Ni, Mo. The thin interfacial layer can be directly deposited on the cathode active material, for example, in a fluidized bed ALD-reactor. The cathode active material is the main element in the composition of the cathode battery unit. The cathode material is, for example, cobalt, nickel and manganese, which have a crystal structure such as a layered structure, forming a multi-metal oxide material in which lithium is inserted. The cathode active material can preferably be "NMC" (lithium nickel manganese cobalt oxide), NCA (lithium nickel cobalt aluminum oxide), LNO (lithium nickel oxide), LMNO (lithium manganese nickel oxide), or LFP (lithium iron phosphate). For example, the cathode active material can be NMC622 or NMC811. The thin interfacial layer can be made on the electrode active material powder, on the porous electrode active material, on the electrode active material of different shapes, or on a pre-formed electrode, where the electrode active material can already be combined with conductive carbon and / or a binder and can already be supported by a current collector foil.

[0053] The following examples illustrate various embodiments of the present invention and are not a limitation.

[0054] Example 1

[0055] Synthesis of tert-butylimino cyclopentadienyl ethoxy niobium (Nb(=NtBu)Cp(OEt)2)

[0056] A solution of ethanol (0.58 g, 12.6 mmol) was added dropwise to a solution of Nb(=NtBu)Cp(NMe2)2 (2 g, 6.3 mmol) in 30 mL of toluene at -78 °C. After stirring the mixture at room temperature for 12 h, the solvent was removed under vacuum to obtain a yellow oil. Then, the material was purified by distillation at 100 °C under 25 mTorr to obtain 1.34 g (66.6%) of a yellow oil. The material was characterized by the following: NMR 1 H (δ, ppm, C6D6): 6.18 (s, 5H), 4.54 (q, 4H), 1.28 (t, 6H), 1.16 (s, 9H).

[0057] In the open cup TGA analysis, the purified product left a residual mass of 2.1%, which was measured at a temperature ramp rate of 10 °C / min under an atmosphere where nitrogen was flowing at 200 mL / min. These results are shown in Figure 1 which is a TGA graph showing the percentage of weight after temperature increase. The onset temperature of melting (-3.8 °C) and the onset temperature of decomposition (317.3 °C) of the product were measured by differential scanning calorimetry (DSC) and are shown in Figure 4 which.

[0058] Example 2

[0059] Synthesis of tert-butylimino cyclopentadienyl tert-butoxy niobium (Nb(=NtBu)Cp(OtBu)2)

[0060] A solution of tert-butanol (0.93 g, 12.6 mmol) was added dropwise to a solution of Nb(=NtBu)Cp(NMe2)2 (2 g, 6.3 mmol) in 30 mL of toluene at -78 °C. After the mixture was stirred at room temperature for 12 h, the solvent was removed under vacuum to obtain a yellow oil. Then, the material was purified by distillation at 100 °C under 25 mTorr to obtain 2.0 g (84.6%) of a yellow oil. The material was characterized by NMR 1 H (δ, ppm, C6D6): 6.17 (s, 5H), 1.32 (s, 18H), 1.21 (s, 9H).

[0061] In the open cup TGA analysis, the purified product left a residual mass of 0.6%, which was measured at a temperature ramp rate of 10 °C / min under an atmosphere where nitrogen was flowing at 200 mL / min. These results are shown in Figure 2 which is a TGA graph showing the percentage of weight after temperature increase. The onset temperature of melting (34.5 °C) and the onset temperature of decomposition (285.1 °C) of the product were measured by differential scanning calorimetry (DSC) and are shown in Figure 5 which.

[0062] Example 3

[0063] Synthesis of tert-butylimino cyclopentadienyl sec-butoxy niobium (Nb(=NtBu)Cp(OsBu)2)

[0064] A solution of sec-butanol (0.93 g, 12.6 mmol) was added dropwise to a solution of Nb(=NtBu)Cp(NMe2)2 (2g, 6.3 mmol) in 30 mL of toluene at -78 °C. After stirring the mixture at room temperature for 12 h, the solvent was removed under vacuum to give a yellow oil. Then, the material was purified by distillation up to 125 °C at 25 mTorr to give 1.75 g (74%) of a yellow oil. The material was characterized as follows: NMR 1 H (δ, ppm, C6D6): 6.19 (s, 5H), 4.49 (m, 2H), 1.61 (m, 2H), 1.49 (m, 2H), 1.31 (d, 3H), 1.26 (d, 3H), 1.18 (s, 9H), 0.99 (t, 6H).

[0065] In an open cup TGA analysis, the purified product left a residual mass of 1.3%, which was measured at a temperature ramp rate of 10 °C / min in an atmosphere where nitrogen was flowing at 200 mL / min. These results are shown in Figure 3 which is a TGA plot showing the percentage of weight after temperature increase. The onset temperature of product decomposition (318.6 °C) was measured by differential scanning calorimetry (DSC) and is shown in Figure 6 .

[0066] Other examples:

[0067] 1. Nb(=NtBu)(RCp)(OEt)2 can be synthesized in the following manner.

[0068] (R = H or C1-C10 alkyl group)

[0069] A solution of ethanol was added dropwise to a solution of Nb(=NtBu)(RCp)(NMe2)2 in toluene at -78 °C. After stirring the mixture at room temperature for 12 h, the solvent was removed under vacuum. Then, the material was purified by distillation or sublimation to obtain the final product.

[0070] 2. Nb(=NR)(Cp)(OEt)2 can be synthesized in the following manner.

[0071] (R = H or C1-C10 alkyl group)

[0072] A solution of ethanol (12.6 mmol) was added dropwise to a solution of Nb(=NR)Cp(NMe2)2 in toluene at -78 °C. After stirring the mixture at room temperature for 12 h, the solvent was removed under vacuum. Then, the material was purified by distillation or sublimation to obtain the final product.

[0073] 3. V(=NtBu)(Cp)(OEt)2 can be synthesized in the following manner.

[0074] A solution of ethanol (12.6 mmol) was added dropwise to a solution of V(=NtBu)Cp(NMe2)2 in toluene at -78 °C. After stirring the mixture at room temperature for 12 h, the solvent was removed under vacuum. Then, the material was purified by distillation or sublimation to obtain the final product.

[0075] In addition, Figure 7 A thermogravimetric analysis (TGA) graph is presented, which shows the weight percentage of niobium(IV) tert-butylimido cyclopentadienyl dimethylamide (Nb(=NtBu)Cp(NMe2)2) as the temperature increases, which is a precursor selected as a reference in the prior art.

[0076] The following table illustrates the property comparison of the following precursors:

[0077] Compound Temperature at 133 Pa <![CDATA[Nb(=NtBu)Cp(OEt)2]]> 100℃ <![CDATA[Nb(=NtBu)Cp(OtBu)2]]> 105℃ <![CDATA[Nb(=NtBu)Cp(OsBu)2]]> 119℃ <![CDATA[Nb(=NtBu)Cp(NMe2)(OtBu)]]> 106℃ <![CDATA[Nb(=NtBu)Cp(NMe2)2]]> 117℃ <![CDATA[Nb(Cp)2(iPr-amd)2]]> 170℃

[0078] Conclusion:

[0079] Compared with Nb(=NtBu)Cp(NMe2)2, the disclosed precursor compound has high thermal stability, high volatility, and low viscosity. These properties make the chemical vapor deposition process more effective and efficient.

[0080] Figure 1 is a thermogravimetric analysis (TGA) graph showing the weight percentage of niobium(IV) tert-butylimido cyclopentadienyl ethoxide (Nb(=NtBu)Cp(OEt)2) as the temperature increases.

[0081] Figure 2 is a thermogravimetric analysis (TGA) graph showing the weight percentage of niobium(IV) tert-butylimido cyclopentadienyl tert-butoxide (Nb(=NtBu)Cp(OtBu)2) as the temperature increases.

[0082] Figure 3 is a thermogravimetric analysis (TGA) graph showing the weight percentage of niobium(IV) tert-butylimido cyclopentadienyl sec-butoxide (Nb(=NtBu)Cp(OsBu)2) as the temperature increases.

[0083] Figure 4 is the differential scanning calorimetry (DSC) of niobium(IV) tert-butylimido cyclopentadienyl ethoxide (Nb(=NtBu)Cp(OEt)2).

[0084] Figure 5 is the differential scanning calorimetry (DSC) of niobium(IV) tert-butylimido cyclopentadienyl tert-butoxide (Nb(=NtBu)Cp(OtBu)2).

[0085] Figure 6 It is the differential scanning calorimetry (DSC) of tert-butylimino cyclopentadienyl sec-butoxy niobium (Nb(=NtBu)Cp(OsBu)2).

[0086] Figure 7 It is a thermogravimetric analysis (TGA) graph showing the weight percentage of tert-butylimino cyclopentadienyl dimethylamino niobium (Nb(=NtBu)Cp(NMe2)2) as the temperature increases.

Claims

1. A metal-containing film-forming composition comprising a precursor having the following formula: Among them, M = V or Nb or Ta; R 1 -R 3 = independently, H or a C1-C10 alkyl group; where each R 4 is H or a C1-C10 alkyl group or a fluorine group; n ≤ 5.

2. The metal-containing film-forming composition according to claim 1, wherein M is vanadium.

3. The metal-containing film-forming composition according to claim 1, wherein, M is niobium.

4. The metal-containing film-forming composition according to claim 1, wherein, R 1 is H, R 2 is tBu; R 3 and R 4 are Et.

5. The metal-containing film-forming composition according to claim 1, wherein R 1 is H, R 2 , R 3 and R 4 is tBu.

6. The metal-containing film-forming composition according to claim 1, wherein R 1 is H, R 2 is tBu; R 3 and R 4 is sBu.

7. A metal-containing film-forming composition comprising a precursor having the following formula: Among them, M = V or Nb or Ta; R 1 -R 3 = independently, H or a C1-C10 alkyl group; wherein R 4 to R 10 are each independently H or a C1-C10 alkyl group or a fluorine group.

8. The metal-containing film-forming composition according to claim 7, wherein, M is vanadium.

9. The metal-containing film-forming composition according to claim 7, wherein, M is niobium.

10. A metal-containing film-forming composition comprising a precursor having the following formula: Among them, M = V or Nb or Ta; R 1 -R 2 = independently, H or a C1-C10 alkyl group; wherein R 4 and R 5 are each independently H or a C1-C10 alkyl group, or a fluorine group.

11. The metal-containing film-forming composition according to claim 10, wherein, M is vanadium.

12. The metal-containing film-forming composition according to claim 10, wherein, M is niobium.

13. A metal-containing film-forming composition comprising a precursor having the following formula: Among them, M = V or Nb or Ta; R 1 -R 3 = independently, H or a C1-C10 alkyl group; wherein R 4 to R 6 are each independently H or a C1-C10 alkyl group, or a fluorine group.

14. The metal-containing film-forming composition according to claim 13, wherein, M is vanadium.

15. The metal-containing film-forming composition according to claim 13, wherein, M is niobium.

16. A method of forming a metal-containing film, the method comprising introducing a vapor of the metal-containing film-forming composition according to any one of claims 1 to 15 into a reactor having a substrate therein; and depositing at least a portion of the precursor on the substrate.

17. The method according to claim 16, further comprising introducing a reactant into the reactor.

18. The method according to claim 17, wherein, The reactant is selected from the group consisting of O2, O3, H2O, H2O2, NO, N2O, NO2, TMPO, their oxygen radicals, and mixtures thereof.

19. The method according to claim 17, wherein, M is Nb, and the niobium-containing film-forming composition and the reactant are introduced into the chamber in sequence, and the reactor is configured for atomic layer deposition.

20. The method according to claim 16, wherein, The substrate is a cathode active material powder.

21. The method according to claim 16, wherein, The substrate is a cathode material, and the cathode material is composed of a cathode active material powder, conductive carbon, and a binder material deposited on a current collector foil.

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