Nb precursor, preparation method and application thereof

Abstract

The application belongs to the technical field of semiconductor processing, and specifically discloses a Nb precursor, and a chemical structure of the Nb precursor is represented by a chemical formula (I): the chemical formula (I) M(NR0)[XCR1R2(CR3R4) a QR5R6]3.The application provides the Nb precursor, the Nb precursor not only has better thermal stability, can satisfy the deposition demand of higher temperature, and the Nb precursor has less C and N impurity content in a thin film in thin film deposition.

Description

Technical Field

[0001] This invention belongs to the field of semiconductor processing technology, and particularly relates to an Nb precursor, its preparation method and application. Background Technology

[0002] Atomic Layer Deposition (ALD) is a thin film deposition technique based on surface self-limiting reactions, enabling precise control of material composition and morphology at the nanoscale. It relies on the alternating introduction of two or more precursors in a reaction chamber, forming atomically thin films through chemisorption and reaction. Each reaction is self-limiting, meaning each chemisorption saturates the surface, preventing over-reaction and thus achieving precise control over film thickness.

[0003] Due to its excellent physical, chemical, optical, and electronic properties (such as high refractive index, large optical band gap, good chemical stability, and corrosion resistance), Nb₂O₅ is widely used in optical interference filters, electrochemical thin films, and gas sensors. Specifically, Nb₂O₅ has a wide band gap (band gap = 3.6 eV), high refractive index (n = 2.4), and high dielectric constant (29–200), making it a promising transparent oxide semiconductor widely used in capacitor dielectric layers in semiconductors, anti-reflective films in optical devices, and catalyst-supporting oxides in new energy materials. In dynamic random access memory (DRAM) applications, Nb₂O₅ is gradually attracting interest as a replacement for the widely recognized SrTiO₃ or Al-doped TiO₂ films with higher dielectric constants.

[0004] In recent years, halogen-free, thermally stable metallic Nb precursors have been gradually developed to achieve higher quality Nb₂O₅ atomic layer deposition. These precursor products include: tBuN = Nb(NEt₂)₃ [TBTDEN], tBuN = Nb(NEtMe)₃ [TBTEMN], and t-amyl N = Nb(O₂O₅)₃. t Bu)3, etc. Among them, TBTDEN and TBTEMN are currently better liquid precursor materials with a wide ALD window of 100-300℃. Although these imine-type precursors have good thermal stability, they not only cannot meet the current requirements for higher thermal stability of metal Nb precursors, but also have high C and N impurity content in thin film deposition, which cannot meet the requirements for higher quality atomic layer deposition. Summary of the Invention

[0005] The purpose of this invention is to overcome the above-mentioned problems in the prior art and provide an Nb precursor that not only has better thermal stability and can meet the deposition requirements at higher temperatures, but also produces films with fewer C and N impurities deposited by the Nb precursor.

[0006] To achieve the above-mentioned technical objectives and effects, the present invention is implemented through the following technical solution:

[0007] In a first aspect, the present invention provides an Nb precursor, the chemical structure of which is represented by chemical formula (Ⅰ):

[0008] Chemical formula (Ⅰ)

[0009] M(NR0)[XCR1R2(CR3R4) a QR5R6]3;

[0010] Where M is Nb;

[0011] X is selected from O or S;

[0012] Q is selected from N or P;

[0013] R0 is selected from C1-C5 alkyl groups;

[0014] R1-R6 are each independently selected from H, C1-C8 alkyl or C1-C5 alkoxy, and R1, R2, R3 and R4 are not all H at the same time;

[0015] a is an integer greater than or equal to 0.

[0016] Furthermore, R0 is a C3-C5 alkyl group.

[0017] Furthermore, R1-R6 are selected from H, C1-C8 alkyl groups, and R1, R2, R3, and R4 are not all H.

[0018] Furthermore, a is an integer ≥ 1; preferably, a is an integer from 1 to 5.

[0019] Furthermore, R5 and R6 are each independently selected from methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, or hexyl.

[0020] Furthermore, R0 is n-propyl ( n Pr), isopropyl ( i Pr), n-butyl ( n Bu), isobutyl ( i Bu), tert-butyl ( t Any of the following (Bu).

[0021] Furthermore, R0 is tert-butyl ( t Bu).

[0022] Furthermore, the Nb precursor represented by chemical formula (Ⅰ) is represented by any one of the following chemical formulas (1-1) to (1-2):

[0023] Chemical formula (1-1)

[0024] Nb(NR0)[OCR1R2(CR3R4) a NR5R6]3;

[0025] Chemical formula (1-2)

[0026] Nb(NR0)[SCR1R2(CR3R4) a NR5R6]3;

[0027] In the chemical formulas (1-1)-(1-2), R0 is selected from C1-C5 alkyl groups;

[0028] R1-R6 are each independently selected from H, C1-C8 alkyl or C1-C5 alkoxy, and R1, R2, R3 and R4 are not all H at the same time;

[0029] a is an integer ≥ 0;

[0030] Preferably, the Nb precursor represented by chemical formula (Ⅰ) is represented by the following chemical formula (1-1):

[0031] Chemical formula (1-1)

[0032] Nb(NR0)[OCR1R2(CR3R4) a NR5R6]3;

[0033] In chemical formula (1-1), R0 is selected from C1-C5 alkyl groups;

[0034] R1-R6 are each independently selected from H, C1-C8 alkyl or C1-C5 alkoxy, and R1, R2, R3 and R4 are not all H at the same time;

[0035] a is an integer greater than or equal to 0.

[0036] In one implementation, when M is Nb, X is O, and Q is N, the Nb precursors that can be listed include, but are not limited to:

[0037] Nb(N t Bu)[OCMe2CH2NMe2]3;

[0038] Nb(N t Bu)[OCEt2CH2NMe2]3;

[0039] Nb(N tThis is [OCMe2CH2 CH2NMe2]3;

[0040] Nb(N t This is [OCMe2CH2 CH2 CH2NMe2]3;

[0041] Nb(N t This is [OCHMeCH2NMe2]3;

[0042] Nb(N t This is [OCH2CHMeNMe2]3;

[0043] Nb(N t This is [OCH2CHMeNEt2]3;

[0044] Nb(N t This is [OCH2CHEtNMe2]3;

[0045] Nb(N t This is[OCH2CHEtNEt2]3;

[0046] Nb(N t This)[OCH2CHMeNPr2]3

[0047] Nb(N t This is[OCH2CHEtNPr2]3;

[0048] Nb(N n This is [OCH2CMe2NMe2]3;

[0049] Nb(N n This is [OCH2CMe2NEt2]3;

[0050] Nb(N n This is [OCH2CMe2NPr2]3;

[0051] Nb(N t This is [OCHMeCHMeNMe2]3;

[0052] Nb(N t This is[OCHMeCHEtNMe2]3;

[0053] Nb(N t This is[OCHEtCHEtNMe2]3;

[0054] Nb(N t This is [OCHMeCH2CH2NMe2]3;

[0055] Nb(Nt Bu)[OCHMeCH2CH2CH2NMe2]3;

[0056] Nb(N t Bu)[OCMe2CH2NEt2]3;

[0057] Nb(N t Bu)[OCMe2CH2CH2NEt2]3;

[0058] Nb(N t Bu)[OCMe2CH2CH2CH2NEt2]3;

[0059] Nb(N t Bu)[OCMe2CH2NMeEt]3;

[0060] Nb(N t Bu)[OCMe2CH2CH2NMeEt]3;

[0061] Nb(N t Bu)[OCMe2CH2CH2CH2NMeEt]3;

[0062] Nb(N t Bu)[OCMe2CH2NPr2]3;

[0063] Nb(N t Bu)[OCEt2CH2N n Pr2]3;

[0064] Nb(N t Bu)[OCMe2CH2 CH2N n Pr2]3;

[0065] Nb(N t Bu)[OCEt2CH2 CH2 CH2N n Pr2]3;

[0066] Nb(N t Bu)[OCMe2CH2 CH2 CH2N n Pr2]3;

[0067] Nb(N t Bu)[OCEt2CH2 CH2 CH2 CH2 CH2N n Pr2]3;

[0068] Nb(N t Bu)[OCMeEtCH2 CH2 CH2 CH2 CH2N n Pr2]3;

[0069] Nb(N t It)[OCMe2CH2CH2CH2CH2CH2NMe2]3;

[0070] Nb(N t This is [OCMeEtCH2NMe2]3;

[0071] Nb(N t This)(OCMeEtCH2N n Pr2)3;

[0072] Nb(N t This is [OCMeEtCH2CH2NMe2]3;

[0073] Nb(N t This is [OCMeEtCH2CH2CH2NMe2]3;

[0074] Nb(N t It)[OCMeEtCH2CH2CH2CH2CH2NMe2]3;

[0075] Nb(N t This is [OCMeEtCH2NEt2]3;

[0076] Nb(N t This is [OCMeEtCH2CH2NEt2]3;

[0077] Nb(N t This is [OCMeEtCH2CH2CH2NEt2]3;

[0078] Nb(N t It)[OCMeEtCH2CH2CH2CH2CH2NEt2]3;

[0079] Nb(N t This is [OCMe2CMe2NMe2]3;

[0080] Nb(N t This is [OCMe2CH2CMe2NMe2]3;

[0081] Nb(N t This is [OCMe2CMe2CH2CH2NMe2]3;

[0082] Nb(N t It)[OCMe2CH2CH2CH2CMe2CH2NMe2]3;

[0083] Nb(Nn This is [OCMe2CH2NMe2]3;

[0084] Nb(N n This is [OCMe2CH2CH2NMe2]3;

[0085] Nb(N n This is [OCMe2CH2CH2CH2NMe2]3;

[0086] Nb(N n It)[OCMe2CH2CH2CH2CH2CH2NMe2]3;

[0087] Nb(N n This is [OCMeEtCH2NMe2]3;

[0088] Nb(N n This is [OCMeEtCH2CH2NMe2]3;

[0089] Nb(N n This is [OCMeEtCH2CH2CH2NMe2]3;

[0090] Nb(N n It)[OCMeEtCH2CH2CH2CH2CH2NMe2]3;

[0091] Nb(N n This is [OCMeEtCH2NEt2]3;

[0092] Nb(N n This is [OCMeEtCH2CH2NEt2]3;

[0093] Nb(N n This is [OCMeEtCH2CH2CH2NEt2]3;

[0094] Nb(N n It)[OCMeEtCH2CH2CH2CH2CH2NEt2]3;

[0095] Nb(N n This is [OCMe2CMe2NMe2]3;

[0096] Nb(N n This is [OCMe2CH2CMe2NMe2]3;

[0097] Nb(N n This is [OCMe2CMe2CH2CH2NMe2]3;

[0098] Nb(N n Bu)[OCMe2CH2CH2CH2CMe2CH2NMe2]3;

[0099] Nb(N i Pr)[OCMe2CH2NMe2]3;

[0100] Nb(N i Pr)[OCMe2CH2CH2NMe2]3;

[0101] Nb(N i Pr)[OCMe2CH2CH2CH2NMe2]3;

[0102] Nb(N i Pr)[OCMe2CH2CH2CH2CH2CH2NMe2]3;

[0103] Nb(N i Pr)[OCMeEtCH2NMe2]3;

[0104] Nb(N i Pr)[OCMeEtCH2CH2NMe2]3;

[0105] Nb(N i Pr)[OCMeEtCH2CH2CH2NMe2]3;

[0106] Nb(N i Pr)[OCMeEtCH2CH2CH2CH2CH2NMe2]3;

[0107] Nb(N i Pr)[OCMeEtCH2NEt2]3;

[0108] Nb(N i Pr)[OCMeEtCH2CH2NEt2]3;

[0109] Nb(N i Pr)[OCMeEtCH2CH2CH2NEt2]3;

[0110] Nb(N i Pr)[OCMeEtCH2CH2CH2CH2CH2NEt2]3;

[0111] Nb(N i Pr)[OCMe2CMe2NMe2]3;

[0112] Nb(N iPr)[OCMe2CH2CMe2NMe2]3;

[0113] Nb(N i Pr)[OCMe2CMe2CH2CH2NMe2]3;

[0114] Nb(N i Pr)[OCMe2CH2CH2CH2CMe2CH2NMe2]3.

[0115] In one embodiment, the Nb precursor structure is represented as: Nb( t BuN)(OC(Me)(Et)CH2NMe2)3.

[0116] In one embodiment, the Nb precursor structure is represented as: Nb( t BuN)(OCH(Me)CH2NMe2)3.

[0117] In one embodiment, the Nb precursor structure is represented as: Nb( t BuN)(OCH(Me)CH(Et)NMe2)3.

[0118] In one embodiment, the Nb precursor structure is represented as: Nb( t BuN)(OCMeEtCH2N i Pr2)3.

[0119] Secondly, the present invention provides a method for preparing an Nb precursor, the method comprising the following steps: mixing M(NR0)(NR2)3 and a solvent under an inert gas protective atmosphere and cooling to below 0°C, and then adding ligand HXCR1R2(CR3R4). a The reaction is carried out by QR5R6. After the reaction is completed, the low-boiling substances are removed to obtain the crude Nb precursor. The crude Nb precursor is then purified to prepare the Nb precursor.

[0120] Further, the solvent is one or more selected from n-hexane, n-pentane, toluene, xylene, trimethylbenzene, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, and methyl tert-butyl ether;

[0121] The M(NR0)L(NR2)2 and HXCR1R2(CR3R4) a The molar ratio of QR5R6 is 1:1-5, preferably 1:1.5-3.

[0122] Furthermore, the purification methods that can be listed include, but are not limited to, one or more of filtration, distillation, adsorption, crystallization, extraction, and ion exchange.

[0123] Thirdly, the present invention provides a method for applying an Nb precursor in thin film deposition, the method comprising the following steps: adsorbing an Nb precursor onto a substrate surface and depositing it.

[0124] Furthermore, the deposition method includes, but is not limited to, one of chemical vapor deposition (CVD), atomic layer deposition (ALD), and plasma-enhanced atomic layer deposition (PEALD); even further, the deposition method is atomic layer deposition (ALD).

[0125] In one embodiment, the substrates that may be listed include, but are not limited to, Si-based substrates, Cu-based substrates, Ti-based substrates, and Mo-based substrates.

[0126] Furthermore, the deposition temperature of the atomic layer deposition is 250-400℃, such as 250℃, 260℃, 270℃, 280℃, 290℃, 300℃, 310℃, 320℃, 330℃, 340℃, 350℃, 360℃, 370℃, 380℃, 390℃, and 400℃.

[0127] Compared with the prior art, the beneficial effects of the present invention are:

[0128] 1. This invention provides an Nb precursor with better thermal stability and a wider ALD window, which can meet the deposition requirements at higher temperatures.

[0129] 2. The Nb precursor provided by this invention, compared with the existing widely used niobium precursor (tert-butylimino)tris(diethylamino)niobium (TBTDEN), can be deposited at higher temperatures and has less C and N impurities in the film, which can meet the current demand for higher thermal stability and higher quality atomic layer deposition of metallic Nb precursors. Attached Figure Description

[0130] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this application, illustrate exemplary embodiments of the invention and, together with their description, serve to explain the invention and do not constitute an undue limitation thereof. In the drawings:

[0131] Figure 1 This is the characteristic photoelectron spectrum of Nb in the XPS analysis curve of the thin film prepared in Example 5 of this invention;

[0132] Figure 2 This is the characteristic photoelectron spectrum of O in the XPS analysis curve of the thin film prepared in Example 5 of this invention;

[0133] Figure 3 This is the characteristic photoelectron spectrum of N in the XPS analysis curve of the thin film prepared in Example 5 of this invention;

[0134] Figure 4 This is the characteristic photoelectron spectrum of C in the XPS analysis curve of the thin film prepared in Example 5 of this invention;

[0135] Figure 5 This is the characteristic photoelectron spectrum of Nb in the XPS analysis curve of the thin film prepared in Comparative Example 1 of this invention;

[0136] Figure 6 This is the characteristic photoelectron spectrum of O in the XPS analysis curve of the thin film prepared in Comparative Example 1 of this invention;

[0137] Figure 7 This is the characteristic photoelectron spectrum of N in the XPS analysis curve of the thin film prepared in Comparative Example 1 of this invention;

[0138] Figure 8 This is the characteristic photoelectron spectrum of C in the XPS analysis curve of the thin film prepared in Comparative Example 1 of this invention;

[0139] Figure 9 This is the ALD deposition window of the metal Nb precursor provided in Embodiment 1 of the present invention;

[0140] Figure 10 This is the ALD deposition window of the precursor TBTDEN in Comparative Example 1 of this invention. Detailed Implementation

[0141] The technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0142] Example 1

[0143] This embodiment provides a metallic Nb precursor with the following structure: Nb( t BuN)(OC(Me)(Et)CH2NMe2)3;

[0144] This embodiment also provides a method for preparing a metallic Nb precursor, the method being: under nitrogen protection, Nb(…) is added to a round-bottom flask… t 3300g of BuN)(NEt2) and 2L of n-hexane were mixed, and the system was cooled to -20℃. 342g of the ligand HOC(Me)(Et)CH2NMe2 was added with stirring. The reaction was carried out for 8 hours. Low-boiling substances were removed, and the residue was distilled under reduced pressure to obtain Nb( tBuN)(OC(Me)(Et)CH2NMe2)3336g, product yield 79%.

[0145] Example 2

[0146] This embodiment provides a metallic Nb precursor with the following structure: Nb( t BuN)(OCH(Me)CH2NMe2)3;

[0147] This embodiment also provides a method for preparing a metallic Nb precursor, the method being: under nitrogen protection, Nb(…) is added to a round-bottom flask… t 3300g of BuN)(NEt2) was mixed with 3L of n-hexane. The system was cooled to 0°C, and 269g of ligand HOCH(Me)CH2NMe2 was added with stirring. The reaction was carried out for 4 hours. Low-boiling substances were removed, and the residue was distilled under reduced pressure to obtain Nb( t BuN)(OCH(Me)CH2NMe2)3292g, product yield 81%.

[0148] Example 3

[0149] This embodiment provides a metallic Nb precursor with the following structure: Nb( t BuN)(OCH(Me)CH(Et)NMe2)3;

[0150] This embodiment also provides a method for preparing a metallic Nb precursor, the method being: under nitrogen protection, Nb(…) is added to a round-bottom flask… t 3300g of BuN)(NEt2) was mixed with 1.5L of n-hexane. The system was cooled to 0℃, and 342g of ligand HOCH(Me)CH(Et)NMe2 was added with stirring. The reaction was carried out for 6 hours. Low-boiling substances were removed, and the residue was distilled under reduced pressure to obtain Nb( t BuN)(OCH(Me)CH(Et)NMe2)3324g, product yield 76%.

[0151] Example 4

[0152] This embodiment provides a metallic Nb precursor with the following structure: Nb( t BuN)(OCMeEtCH2N i Pr2)3;

[0153] This embodiment also provides a method for preparing a metallic Nb precursor, the method being: under nitrogen protection, Nb(…) is added to a round-bottom flask… t Mix 3300g of BuN)(NEt2) with 1L of n-hexane, cool the system to 0℃, and add the ligand HOCH(Me)(Et)CH2N while stirring. iPr2415g, reacted for 10h, low-boiling substances were removed, and the residue was distilled under reduced pressure to obtain Nb( t BuN)(OC(Me)(Et)CH2N i Pr2) 3402g, product yield 72%.

[0154] Example 5

[0155] This embodiment provides a method for using Nb( t A method for depositing Nb2O5 thin films using BuN)(OC(Me)(Et)CH2NMe2)3 (prepared from Example 1) as a precursor includes the following steps:

[0156] (1) The source bottle of the niobium precursor prepared and purified to a purity of 6N in Example 1 is heated to 90°C, the precursor transport pipeline and valve are heated to 110°C, the ALD cavity temperature is heated to 350°C, and the ALD cavity is evacuated to 10Pa.

[0157] (2) The vapor of the niobium precursor is introduced into the ALD cavity through an inert gas carrier gas for 3 seconds, and the precursor vapor forms a chemical adsorption on the substrate surface.

[0158] (3) The unadsorbed precursors and reaction byproducts were purged with inert gas for 10 seconds.

[0159] (4) The reaction gas O3 is introduced into the ALD cavity through the carrier gas. The flow rate of O3 is 100 sccm. O3 reacts completely with the precursor adsorbed on the substrate. The oxidation duration is 1 s.

[0160] (5) Use an inert gas to purge the unreacted O3 and reaction byproducts for 10 seconds, and deposit a single layer of Nb2O5 film on the substrate surface.

[0161] (6) Repeat steps (2)-(5) for 500 cycles to form a Nb2O5 film of the required thickness.

[0162] Figure 1-4 This is the XPS analysis curve of the thin film prepared in Example 5. Specifically, Figure 1-4 The characteristic photoelectron spectra of Nb, O, N, and C in the thin films prepared in Example 5 are shown below. XPS elemental analysis indicates that the deposited metallic Nb₂O₅ thin film contains 0.82% C and 0.06% N impurities. Specific data are shown in the table below.

[0163] Table 1

[0164] element Nb3d O1s C1s N1s O / Nb Element content / % 30.1 69.02 0.82 0.06 2.29

[0165] Figure 9The ALD deposition window for the metal Nb precursor provided in Example 1 is formed by... Figure 9 It can be seen that its deposition window is 250-400℃.

[0166] Example 6

[0167] This embodiment provides a method for using Nb( t The method for depositing Nb2O5 thin films using BuN)(OCH(Me)CH(Et)NMe2)3 as a precursor differs from that in Example 5 in that the precursor in this example is a niobium precursor with a purity of 6N prepared in Example 3, and the remaining operation steps are performed in accordance with Example 5.

[0168] XPS elemental analysis showed that the deposited Nb₂O₅ thin film contained 0.75% C and 0.08% N impurities. Specific data are shown in the table below.

[0169] Table 2

[0170] element Nb3d O1s C1s N1s O / Nb Element content / % 29.98 69.19 0.75 0.08 2.31

[0171] Example 7

[0172] This embodiment provides a method for using Nb( t BuN)(OCMeEtCH2N i The method for depositing Nb2O5 thin films using Pr2)3 as a precursor differs from that in Example 5 in that the precursor in this example is a niobium precursor with a purity of 6N prepared in Example 4, and the remaining operation steps are performed in accordance with Example 5.

[0173] XPS elemental analysis showed that the deposited Nb₂O₅ thin film contained 1.14% C and 0.12% N impurities. Specific data are shown in the table below.

[0174] Table 3

[0175] element Nb3d O1s C1s N1s O / Nb Element content / % 29.87 68.87 1.14 0.12 2.31

[0176] Example 8

[0177] This embodiment provides a method for using Nb( t The method for depositing Nb2O5 thin films using BuN)(OCH(Me)CH2NMe2)3 as a precursor differs from that in Example 5 in that the precursor in this example is a niobium precursor with a purity of 6N prepared in Example 2, and the remaining operation steps are performed in accordance with Example 5.

[0178] XPS elemental analysis showed that the deposited Nb₂O₅ thin film contained 0.85% C and 0.07% N impurities. Specific data are shown in the table below.

[0179] Table 4

[0180] element Nb3d O1s C1s N1s O / Nb Element content / % 29.98 69.10 0.85 0.07 2.30

[0181] Comparative Example 1

[0182] This comparative example provides a method for depositing ALD Nb2O5 thin films using TBTDEN as a precursor:

[0183] (1) Heat the 6N niobium precursor TBTDEN to 80°C, heat the precursor transport pipeline and valves to 100°C, heat the ALD cavity to 300°C, and evacuate the ALD cavity to 10Pa.

[0184] (2) The precursor vapor is introduced into the ALD cavity through an inert carrier gas for 2 seconds, and the precursor vapor forms a chemical adsorption on the substrate surface.

[0185] (3) The unadsorbed precursors and reaction byproducts were purged with inert gas for 10 seconds.

[0186] (4) The reaction gas O3 is introduced into the ALD cavity through the carrier gas. The flow rate of O3 is 100 sccm. O3 reacts completely with the ruthenium precursor adsorbed on the substrate. The oxidation time is 1 s.

[0187] (5) Use an inert gas to purge the unreacted O3 and reaction byproducts for 10 seconds, and deposit a single layer of Nb2O5 film on the substrate surface.

[0188] (6) Repeat steps (2)-(5) for 500 cycles to form a Nb2O5 film of the required thickness.

[0189] Figure 5-8 The image shows the XPS analysis curves of the thin film prepared in Comparative Example 1. Specifically, Figure 5-8 The characteristic photoelectron spectra of Nb, O, N, and C in the thin film prepared in Comparative Example 1 are shown below. XPS elemental analysis indicates that the deposited metallic Nb₂O₅ thin film contains 1.98% C and 0.30% N impurities. Specific data are shown in the table below.

[0190] Table 5

[0191] element Nb3d O1s C1s N1s O / Nb Element content / % 29.15 68.57 1.98 0.30 2.30

[0192] Figure 10 The ALD deposition window for the metallic Nb precursor provided in Comparative Example 1 is provided by Figure 10 It can be seen that its deposition window is 150-300℃.

[0193] Comparative Example 2

[0194] This comparative example provides a method for depositing Nb2O5 thin films using TBTDEN as a precursor. Compared with Comparative Example 1, in this method, the ALD chamber temperature is heated to 350°C, and the rest of the operation process is the same as Comparative Example 1. .

[0195] XPS elemental analysis showed that the deposited Nb₂O₅ thin film contained 2.84% C and 0.32% N impurities. Specific data are shown in the table below.

[0196] Table 6

[0197] element Nb3d O1s C1s N1s O / Nb Element content / % 28.95 67.89 2.84 0.32 2.35

[0198] Comparative Example 3

[0199] This comparative example provides a method using Nb( t Compared to Example 5, the method of depositing Nb2O5 thin films using BuN)(OC(Me)(Et)CH2OMe)3 as a precursor in this method uses Nb( t BuN)(OC(Me)(Et)CH2OMe)3, the rest of the operation process is the same as in Example 5;

[0200] XPS elemental analysis showed that the deposited Nb₂O₅ thin film contained 2.21% C and 0.09% N impurities. Specific data are shown in the table below.

[0201] Table 7

[0202] element Nb3d O1s C1s N1s O / Nb Element content / % 69.05 28.65 2.21 0.09 2.41

[0203] The C and N impurity content data of the films prepared in Examples 5-8 and the comparative examples are summarized in Table 6.

[0204] Table 8

[0205] Group C content / % N content / % Example 5 0.82 0.06 Example 6 0.75 0.08 Example 7 1.14 0.12 Example 8 0.85 0.07 Comparative Example 1 1.98 0.30 Comparative Example 2 2.84 0.32 Comparative Example 3 2.21 0.09

[0206] As can be seen from the data of the examples and comparative examples in Table 8, when the metal Nb precursor provided by the present invention is used for thin film deposition, the impurity C content in the thin film is less than that in the comparative examples. As can be seen from Example 7 and Comparative Example 3, although the impurity N content in the thin film prepared in Comparative Example 3 is less than that in Example 7, its impurity C content is significantly higher than that in Example 7. This indicates that the metal Nb precursor provided by the present invention can meet the requirements of higher quality atomic layer deposition when applied to thin film deposition.

[0207] In the description of this specification, references to terms such as "an embodiment," "example," "specific example," etc., indicate that a specific feature, structure, material, or characteristic described in connection with that embodiment or example is included in at least one embodiment or example of the invention. In this specification, illustrative expressions of the above terms do not necessarily refer to the same embodiment or example. Furthermore, the specific features, structures, materials, or characteristics described may be combined in any suitable manner in one or more embodiments or examples.

[0208] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. Those skilled in the art should understand that the present invention is not limited to the above embodiments. The embodiments and descriptions in the specification are merely illustrative of the principles of the invention. Various changes and modifications can be made to the invention without departing from its spirit and scope, and all such changes and modifications fall within the scope of the claimed invention.

Claims

1. A Nb precursor, characterized in that, The chemical structure of the Nb precursor is represented by formula (I): Chemical formula (I) M(NR0) [XCR1R2(CR3R4) a QR5R6]3; Wherein, M is Nb; X is selected from O; Q is selected from N; R0 is selected from C3-C5 alkyl; R1-R6 are each independently selected from H, C1-C8 alkyl, and R1, R2, R3, R4 are not simultaneously H; a is 1.

2. The Nb precursor of claim 1, wherein, R5, R6 are each independently selected from methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl or hexyl.

3. The Nb precursor of claim 1, wherein, R0 is any one of n-propyl, isopropyl, n-butyl, isobutyl, tert-butyl.

4. A method of producing the Nb precursor according to any one of claims 1 to 3, characterized by, The preparation method comprises the following steps: mixing M(NR0)(NR2)3 and a solvent under an inert gas protection atmosphere, and cooling to below 0 DEG C; then adding a ligand HXCR1R2(CR3R4) a QR5R6 is carried out, low boiling point substances are removed after the reaction is completed, and the Nb precursor crude product is obtained; and the Nb precursor crude product is purified to prepare the Nb precursor.

5. The method of claim 4, wherein the Nb precursor is prepared by the process of claim 1. The solvent is one or more of n-hexane, n-pentane, toluene, xylene, trimethylbenzene, diethyl ether, tetrahydrofuran, ethylene glycol dimethyl ether, methyl tert-butyl ether; said M(NR0)(NR2)3and HXCR1R2(CR3R4) a the molar ratio of QR5R6is 1:1-5.

6. A method of using the Nb precursor according to any one of claims 1 to 3 in thin film deposition, characterized in that, The method comprises the following steps: adsorbing the Nb precursor to the surface of the substrate and depositing.

7. The method of claim 6, wherein the Nb precursor is used in thin film deposition. In the deposition process, the deposition temperature is 250-400℃.

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