Nb precursor and preparation method and application thereof

Abstract

The invention belongs to the technical field of semiconductor processing, and particularly discloses an Nb precursor, and the chemical structure of the Nb precursor is represented by the chemical formula (I): M (NR0) [XCR1R2 (CR3R4) aQR5R6] 3. According to the Nb precursor provided by the invention, the Nb precursor not only has better thermal stability and can meet the deposition requirement at a higher temperature, but also the content of C and N impurities in a film is lower in the film deposition of the Nb precursor.

Description

Technical Field

[0001] The invention belongs to the technical field of semiconductor processing, and in particular relates to a Nb precursor and a preparation method and application thereof. Background Art

[0002] Atomic layer deposition (ALD) is a thin film deposition technology based on surface self-limiting reaction, which can accurately control the material composition and morphology at the nanoscale. It relies on the alternating introduction of two or more precursors into the reaction chamber and the formation of atomic-level thin films through chemical adsorption and reaction. Each reaction is self-limiting, that is, each chemical adsorption will saturate the surface without overreaction, thereby achieving precise control of the film thickness.

[0003] Nb 2 O 5 Due to its good physical, chemical, optical and electronic properties (such as high refractive index, large optical band gap, good chemical stability and corrosion resistance, etc.), it is widely used in optical interference filters, electrochemical films, gas sensors, etc. 2 O 5 With a wide band gap (band gap = 3.6 eV), high refractive index (n = 2.4), and high dielectric constant (29-200), Nb can be used as a promising transparent oxide semiconductor and is widely used in capacitor dielectric layers in semiconductors, anti-reflection films in optical devices, and catalyst support oxides for new energy materials. In the application of dynamic random access memory (DRAM), Nb 2 O 5 It has gradually attracted people's interest to replace the widely known SrTiO with a higher dielectric constant. 3 or Al-doped TiO 2 film.

[0004] In recent years, halogen-free and thermally stable metallic Nb precursors have been gradually developed to achieve higher quality Nb 2 O 5 Atomic layer deposition. Such precursor products include: tBuN=Nb(NEt 2 ) 3

TBTDEN

TBTEMN

[0005] The object of the present invention is to overcome the above problems existing in the prior art and to provide a Nb precursor, which not only has better thermal stability and can meet the deposition requirements of higher temperatures, but also the thin film deposited by the Nb precursor has less C and N impurities.

[0006] In order to achieve the above technical objectives and the above technical effects, the present invention is implemented through the following technical solutions:

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

[0008] Chemical formula (Ⅰ)

[0009] M(NR 0 )[XCR 1 R 2 (CR 3 R 4 ) a QR 5 R 6 ] 3 ;

[0010] Wherein, M is Nb;

[0011] X is selected from O or S;

[0012] Q is selected from N or P;

[0013] R 0 An alkyl group selected from C1-C5;

[0014] R 1 -R 6 are each independently selected from H, C1-C8 alkyl or C1-C5 alkoxy, and R 1 , R 2 , R 3 , R 4 Not at the same time H;

[0015] a is an integer ≥0.

[0016] Furthermore, R 0 It is a C3-C5 alkyl group.

[0017] Furthermore, R 1 -R 6 is selected from H, C1-C8 alkyl, and R 1 , R 2 , R 3 , R 4 Not H at the same time.

[0018] Furthermore, a is an integer ≥1; preferably, a is an integer of 1-5.

[0019] Furthermore, R 5 , R 6 Each is independently selected from methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl or hexyl.

[0020] Furthermore, R 0 For n-propyl ( n Pr), isopropyl ( i Pr), n-butyl ( n Bu), isobutyl ( i Bu), tert-butyl ( t Bu).

[0021] Furthermore, R 0 For tert-butyl t Bu).

[0022] Further, the Nb precursor represented by the 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(NR 0 )[OCR 1 R 2 (CR 3 R 4 ) a NR 5 R 6 ] 3 ;

[0025] Chemical formula (1-2)

[0026] Nb(NR 0 )[SCR 1 R 2 (CR 3 R 4 ) a NR 5 R 6 ] 3 ;

[0027] In the chemical formulas (1-1) to (1-2), R 0 An alkyl group selected from C1-C5;

[0028] R 1 -R 6 are each independently selected from H, C1-C8 alkyl or C1-C5 alkoxy, and R 1 , R 2 , R 3 , R 4 Not at the same time H;

[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(NR 0 )[OCR 1 R 2 (CR 3 R 4 ) a NR 5 R 6 ] 3 ;

[0033] In the chemical formula (1-1), R 0 An alkyl group selected from C1-C5;

[0034] R 1 -R 6 are each independently selected from H, C1-C8 alkyl or C1-C5 alkoxy, and R 1 , R 2 , R 3 , R 4 Not at the same time H;

[0035] a is an integer ≥0.

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

[0037] Nb(N t Bu)[OCMe 2 CH 2 NMe 2 ] 3 ;

[0038] Nb(N t Bu)[OCEt 2 CH 2 NMe2 ] 3 ;

[0039] Nb(N t Bu)[OCMe 2 CH 2 CH 2 NMe 2 ] 3 ;

[0040] Nb(N t Bu)[OCMe 2 CH 2 CH 2 CH 2 NMe 2 ] 3 ;

[0041] Nb(N t Bu)[OCHMeCH 2 NMe 2 ] 3 ;

[0042] Nb(N t Bu)[OH 2 CHMeNMe 2 ] 3 ;

[0043] Nb(N t Bu)[OH 2 CHMeNET 2 ] 3 ;

[0044] Nb(N t Bu)[OH 2 CHEtNMe 2 ] 3 ;

[0045] Nb(N t Bu)[OH 2 CHEtNET 2 ] 3 ;

[0046] Nb(N t Bu)[OH 2 CHMeNPr 2 ] 3

[0047] Nb(N t Bu)[OH 2 CHEtNPr 2 ] 3 ;

[0048] Nb(N n Bu)[OCH 2 CMe 2 NMe 2 ] 3 4

[0049] Nb(N n Bu)[OCH 2 CMe 2 NEt 2 ] 3 4

[0050] Nb(N n Bu)[OCH 2 CMe 2 NPr 2 ] 3 4

[0051] Nb(N t Bu)[OCHMeCHMeNMe 2 ] 3 4

[0052] Nb(N t Bu)[OCHMeCHEtNMe 2 ] 3 4

[0053] Nb(N t Bu)[OCHEtCHEtNMe 2 ] 3 4

[0054] Nb(N t Bu)[OCHMeCH 2 CH 2 NMe 2 ] 3 4

[0055] Nb(N t Bu)[OCHMeCH 2 CH 2 CH 2 NMe 2 ] 3 4

[0056] Nb(N t Bu)[OCMe 2 CH 2 NEt 2 ] 3 4

[0057] Nb(N t Bu)[OCMe 2 CH2 CH 2 NEt 2 ] 3 4

[0058] Nb(N t Bu)[OCMe 2 CH 2 CH 2 CH 2 NEt 2 ] 3 4

[0059] Nb(N t Bu)[OCMe 2 CH 2 NMeEt] 3 4

[0060] Nb(N t Bu)[OCMe 2 CH 2 CH 2 NMeEt] 3 4

[0061] Nb(N t Bu)[OCMe 2 CH 2 CH 2 CH 2 NMeEt] 3 4

[0062] Nb(N t Bu)[OCMe 2 CH 2 NPr 2 ] 3 4

[0063] Nb(N t Bu)[OCEt 2 CH 2 N n Pr 2 ] 3 4

[0064] Nb(N t Bu)[OCMe 2 CH 2 CH 2 N n Pr 2 ] 3 4

[0065] Nb(N t Bu)[OCEt 2 CH 2 CH2 CH 2 N n Pr 2 ] 3 ;

[0066] Nb(N t Bu)[OCMe 2 CH 2 CH 2 CH 2 N n Pr 2 ] 3 ;

[0067] Nb(N t Bu)[OCEt 2 CH 2 CH 2 CH 2 CH 2 CH 2 N n Pr 2 ] 3 ;

[0068] Nb(N t Bu)[OCMeEtCH 2 CH 2 CH 2 CH 2 CH 2 N n Pr 2 ] 3 ;

[0069] Nb(N t Bu)[OCMe 2 CH 2 CH 2 CH 2 CH 2 CH 2 NMe 2 ] 3 ;

[0070] Nb(N t Bu)[OCMeEtCH 2 NMe 2 ] 3 ;

[0071] Nb(N t Bu)(OCMeEtCH 2 N n Pr 2 ) 3 ;

[0072] Nb(Nt Bu)[OCMeEtCH 2 CH 2 NMe 2 ] 3 4

[0073] Nb(N t Bu)[OCMeEtCH 2 CH 2 CH 2 NMe 2 ] 3 4

[0074] Nb(N t Bu)[OCMeEtCH 2 CH 2 CH 2 CH 2 CH 2 NMe 2 ] 3 4

[0075] Nb(N t Bu)[OCMeEtCH 2 NEt 2 ] 3 4

[0076] Nb(N t Bu)[OCMeEtCH 2 CH 2 NEt 2 ] 3 4

[0077] Nb(N t Bu)[OCMeEtCH 2 CH 2 CH 2 NEt 2 ] 3 4

[0078] Nb(N t Bu)[OCMeEtCH 2 CH 2 CH 2 CH 2 CH 2 NEt 2 ] 3 4

[0079] Nb(N t Bu)[OCMe 2 CMe 2 NMe 2 ] 3 4

[0080] Nb(N t Bu)[OCMe 2 CH 2 CMe 2 NMe 2 ] 3 ;

[0081] Nb(N t Bu)[OCMe 2 CMe 2 CH 2 CH 2 NMe 2 ] 3 ;

[0082] Nb(N t Bu)[OCMe 2 CH 2 CH 2 CH 2 CMe 2 CH 2 NMe 2 ] 3 ;

[0083] Nb(N n Bu)[OCMe 2 CH 2 NMe 2 ] 3 ;

[0084] Nb(N n Bu)[OCMe 2 CH 2 CH 2 NMe 2 ] 3 ;

[0085] Nb(N n Bu)[OCMe 2 CH 2 CH 2 CH 2 NMe 2 ] 3 ;

[0086] Nb(N n Bu)[OCMe 2 CH 2 CH 2 CH 2 CH 2 CH 2 NMe 2 ] 3 ;

[0087] Nb(Nn Bu)[OCMeEtCH 2 NMe 2 ] 3 ;

[0088] Nb(N n Bu)[OCMeEtCH 2 CH 2 NMe 2 ] 3 ;

[0089] Nb(N n Bu)[OCMeEtCH 2 CH 2 CH 2 NMe 2 ] 3 ;

[0090] Nb(N n Bu)[OCMeEtCH 2 CH 2 CH 2 CH 2 CH 2 NMe 2 ] 3 ;

[0091] Nb(N n Bu)[OCMeEtCH 2 NEt 2 ] 3 ;

[0092] Nb(N n Bu)[OCMeEtCH 2 CH 2 NEt 2 ] 3 ;

[0093] Nb(N n Bu)[OCMeEtCH 2 CH 2 CH 2 NEt 2 ] 3 ;

[0094] Nb(N n Bu)[OCMeEtCH 2 CH 2 CH 2 CH 2 CH 2 NEt 2 ] 3 ;

[0095] Nb(Nn Bu)[OCMe 2 CMe 2 NMe 2 ] 3 ;

[0096] Nb(N n Bu)[OCMe 2 CH 2 CMe 2 NMe 2 ] 3 ;

[0097] Nb(N n Bu)[OCMe 2 CMe 2 CH 2 CH 2 NMe 2 ] 3 ;

[0098] Nb(N n Bu)[OCMe 2 CH 2 CH 2 CH 2 CMe 2 CH 2 NMe 2 ] 3 ;

[0099] Nb(N i Pr)[OCMe 2 CH 2 NMe 2 ] 3 ;

[0100] Nb(N i Pr)[OCMe 2 CH 2 CH 2 NMe 2 ] 3 ;

[0101] Nb(N i Pr)[OCMe 2 CH 2 CH 2 CH 2 NMe 2 ] 3 ;

[0102] Nb(N i Pr)[OCMe 2 CH 2 CH 2 CH 2CH 2 CH 2 NMe 2 ] 3 ;

[0103] Nb(N i Pr)[OCMeEtCH 2 NMe 2 ] 3 ;

[0104] Nb(N i Pr)[OCMeEtCH 2 CH 2 NMe 2 ] 3 ;

[0105] Nb(N i Pr)[OCMeEtCH 2 CH 2 CH 2 NMe 2 ] 3 ;

[0106] Nb(N i Pr)[OCMeEtCH 2 CH 2 CH 2 CH 2 CH 2 NMe 2 ] 3 ;

[0107] Nb(N i Pr)[OCMeEtCH 2 NEt 2 ] 3 ;

[0108] Nb(N i Pr)[OCMeEtCH 2 CH 2 NEt 2 ] 3 ;

[0109] Nb(N i Pr)[OCMeEtCH 2 CH 2 CH 2 NEt 2 ] 3 ;

[0110] Nb(N i Pr)[OCMeEtCH 2 CH 2 CH 2CH 2 CH 2 Nt 2 ] 3 ;

[0111] Nb(N i Pr)[OCMe 2 CMe 2 NMe 2 ] 3 ;

[0112] Nb(N i Pr)[OCMe 2 CH 2 CMe 2 NMe 2 ] 3 ;

[0113] Nb(N i Pr)[OCMe 2 CMe 2 CH 2 CH 2 NMe 2 ] 3 ;

[0114] Nb(N i Pr)[OCMe 2 CH 2 CH 2 CH 2 CMe 2 CH 2 NMe 2 ] 3 .

[0115] In one embodiment, the Nb precursor structure is represented by: Nb( t BuN)(OC(Me)(Et)CH 2 NMe 2 ) 3 .

[0116] In one embodiment, the Nb precursor structure is represented by: Nb( t BuN)(OCH(Me)CH 2 NMe 2 ) 3 .

[0117] In one embodiment, the Nb precursor structure is represented by: Nb( t BuN)(OCH(Me)CH(Et)NMe 2 ) 3 .

[0118] In one embodiment, the Nb precursor structure is represented by: Nb( t BuN)(OCMeEtCH 2 N i Pr 2 ) 3 .

[0119] In a second aspect, the present invention provides a method for preparing a Nb precursor, the preparation method comprising the following steps: in an inert gas atmosphere, 0 )(NR 2 ) 3 Mix with solvent and cool to below 0℃, then add ligand HXCR 1 R 2 (CR 3 R 4 ) a QR 5 R 6 The reaction is carried out, and after the reaction is completed, low-boiling substances are removed to obtain a crude Nb precursor. The crude Nb precursor is purified to prepare a Nb precursor.

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

[0121] The M(NR 0 )L(NR 2 ) 2 and HXCR 1 R 2 (CR 3 R 4 ) a QR 5 R 6 The molar ratio is 1:1-5, preferably 1:1.5-3.

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

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

[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); further, the deposition method is atomic layer deposition (ALD).

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

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

[0127] Compared with the prior art, the present invention has the following beneficial effects:

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

[0129] 2. Compared with the currently used niobium precursor (tert-butylimino)tris(diethylamino)niobium (TBTDEN), the Nb precursor provided by the present invention can be deposited at a higher temperature and has a lower content of C and N impurities in the film, which can meet the current demand for higher thermal stability of metal Nb precursors and higher quality atomic layer deposition. BRIEF DESCRIPTION OF THE DRAWINGS

[0130] The drawings described herein are used to provide a further understanding of the present invention and constitute a part of this application. The exemplary embodiments of the present invention and their descriptions are used to explain the present invention and do not constitute an improper limitation of the present invention. In the drawings:

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

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

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

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

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

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

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

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

[0139] Fig. 9 is the ALD deposition window of the metal Nb precursor provided in Example 1 of the present invention;

[0140] Fig.10 It is the ALD deposition window of the precursor TBTDEN in Comparative Example 1 of the present invention. DETAILED DESCRIPTION

[0141] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0142] Example 1

[0143] This embodiment provides a metal Nb precursor having the structure: Nb( t BuN)(OC(Me)(Et)CH 2 NMe 2 ) 3 ;

[0144] This embodiment also provides a method for preparing a metal Nb precursor, which comprises: adding Nb( t BuN)(NEt 2 ) 3 300g of ethanol and 2L of n-hexane were mixed, the system was cooled to -20°C, and the ligand HOC(Me)(Et)CH 2 NMe 2 342g, reacted for 8h, removed low boiling points, and the residue was distilled under reduced pressure to obtain Nb( t BuN)(OC(Me)(Et)CH 2 NMe 2 ) 3 336g, product yield is 79%.

[0145] Example 2

[0146] This embodiment provides a metal Nb precursor having the structure: Nb( t BuN)(OCH(Me)CH 2 NMe 2 ) 3 ;

[0147] This embodiment also provides a method for preparing a metal Nb precursor, which comprises: adding Nb( t BuN)(NEt 2 ) 3 300g of HOCH(Me)CH 2 NMe 2 269g, react for 4h, remove low boiling points, and distill the residue under reduced pressure to obtain Nb( t BuN)(OCH(Me)CH 2 NMe 2 ) 3 292g, product yield is 81%.

[0148] Example 3

[0149] This embodiment provides a metal Nb precursor having the structure: Nb( t BuN)(OCH(Me)CH(Et)NMe 2 ) 3 ;

[0150] This embodiment also provides a method for preparing a metal Nb precursor, which comprises: adding Nb( t BuN)(NEt 2 ) 3 300g, 1.5L of n-hexane, cool the system to 0℃, add ligand HOCH(Me)CH(Et)NMe under stirring 2 342g, react for 6h, remove low boiling points, and distill the residue under reduced pressure to obtain Nb( t BuN)(OCH(Me)CH(Et)NMe 2 ) 3 324 g, product yield is 76%.

[0151] Example 4

[0152] This embodiment provides a metal Nb precursor having the structure: Nb( t BuN)(OCMeEtCH 2 N i Pr 2 ) 3 ;

[0153] This embodiment also provides a method for preparing a metal Nb precursor, which comprises: adding Nb( t BuN)(NEt 2 ) 3 300g of HOCH(Me)(Et)CH 2 N i Pr 2 415g, react for 10h, remove low boiling points, and distill the residue under reduced pressure to obtain Nb( t BuN)(OC(Me)(Et)CH 2 N i Pr 2 ) 3 402g, product yield is 72%.

[0154] Example 5

[0155] This embodiment provides a method of using Nb( t BuN)(OC(Me)(Et)CH 2 NMe 2 ) 3 (prepared in Example 1) as a precursor to deposit Nb 2 O 5 The method of the thin film comprises 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 chamber temperature is heated to 350° C., and the ALD chamber is evacuated to 10 Pa;

[0157] (2) introducing the vapor of the niobium precursor into the ALD chamber through an inert gas carrier gas for 3 seconds, and the precursor vapor forms chemical adsorption on the surface of the substrate;

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

[0159] (4) Introduce the reactive gas O into the ALD chamber through the carrier gas 3 , O 3 The flow rate is 100 sccm, O 3 Complete reaction with the precursor adsorbed on the substrate, the oxidation duration is 1s;

[0160] (5) Remove the unreacted O 3, and the reaction byproducts were purged clean, the purging time was 10s, and a single layer of Nb was deposited on the substrate surface. 2 O 5 film;

[0161] (6) Repeat steps (2)-(5) for 500 cycles to form the desired thickness of Nb 2 O 5 film.

[0162] Figure 1-4 is the XPS analysis curve spectrum of the film prepared in Example 5. Specifically, Figure 1-4 The characteristic photoelectron spectra of Nb, O, N and C in the film prepared in Example 5 are shown in Figure 5. XPS element analysis shows that the deposited metal Nb 2 O 5 In the film, the impurity C content is 0.82%, and the N content is 0.06%. The 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] Fig. 9 The ALD deposition window of the metal Nb precursor provided in Example 1 is composed of Fig. 9 It can be seen that its deposition window is 250-400°C.

[0166] Example 6

[0167] This embodiment provides a method of using Nb( t BuN)(OCH(Me)CH(Et)NMe 2 ) 3 As a precursor to deposit Nb 2 O 5 The method for preparing a thin film is different from that of Example 5 in that, in this example, the precursor is the niobium precursor with a purity of 6N prepared in Example 3, and the remaining operation steps are carried out with reference to Example 5.

[0168] XPS element analysis shows that the deposited metal Nb 2 O 5 In the film, the impurity C content is 0.75%, and the N content is 0.08%. The 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 of using Nb( t BuN)(OCMeEtCH2 N i Pr 2 ) 3 As a precursor to deposit Nb 2 O 5 The method for preparing a thin film is different from that of Example 5 in that, in this example, the precursor is the niobium precursor with a purity of 6N prepared in Example 4, and the remaining operation steps are carried out with reference to Example 5.

[0173] XPS element analysis shows that the deposited metal Nb 2 O 5 In the film, the impurity C content is 1.14%, and the N content is 0.12%. The 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 of using Nb( t BuN)(OCH(Me)CH 2 NMe 2 ) 3 As a precursor to deposit Nb 2 O 5 The method for preparing a thin film is different from that of Example 5 in that, in this example, the precursor is the niobium precursor with a purity of 6N prepared in Example 2, and the remaining operation steps are carried out with reference to Example 5.

[0178] XPS element analysis shows that the deposited metal Nb 2 O 5 In the film, the impurity C content is 0.85%, and the N content is 0.07%. The 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 Nb using TBTDEN as a precursor. 2 O 5 Thin film method:

[0183] (1) The 6N niobium precursor TBTDEN is heated to 80°C, the precursor transport pipeline and valve are heated to 100°C, the ALD chamber temperature is heated to 300°C, and the ALD chamber is evacuated to 10Pa;

[0184] (2) introducing precursor vapor into the ALD chamber through an inert gas carrier gas for 2 seconds, and the precursor vapor forms chemical adsorption on the substrate surface;

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

[0186] (4) Introduce the reactive gas O into the ALD chamber through the carrier gas 3 , O 3 The flow rate is 100 sccm, O 3 It completely reacts with the ruthenium precursor adsorbed on the substrate, and the oxidation duration is 1s;

[0187] (5) Remove the unreacted O 3 , and the reaction byproducts were purged clean, the purging time was 10s, and a single layer of Nb was deposited on the substrate surface. 2 O 5 film;

[0188] (6) Repeat steps (2)-(5) for 500 cycles to form the desired thickness of Nb 2 O 5 film.

[0189] Figure 5-8 This is the XPS analysis curve of the film prepared in Comparative Example 1. Specifically, Figure 5-8 The characteristic photoelectron spectra of Nb, O, N and C in the film prepared in Comparative Example 1 are shown respectively; XPS element analysis shows that the deposited metal Nb 2 O 5 In the film, the impurity C content is 1.98%, and the N content is 0.30%. The 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] Fig.10 The ALD deposition window of the metal Nb precursor provided in Comparative Example 1 is Fig.10 It can be seen that its deposition window is 150-300°C.

[0193] Comparative Example 2

[0194] This comparative example provides a method for depositing Nb using TBTDEN as a precursor. 2 O 5 Thin film method, 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 element analysis shows that the deposited metal Nb 2 O 5 In the film, the impurity C content is 2.84%, and the N content is 0.32%. The 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 of using Nb( t BuN)(OC(Me)(Et)CH 2 OMe) 3 As a precursor to deposit Nb 2 O 5 The method of the thin film, compared with Example 5, in this method, the precursor is Nb( t BuN)(OC(Me)(Et)CH 2 OMe) 3 The rest of the operation process is the same as that of Example 5;

[0200] XPS element analysis shows that the deposited metal Nb 2 O 5 In the film, the impurity C content is 2.21%, and the N content is 0.09%. The 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 data of the impurity C and N contents in the films prepared in Examples 5-8 and Comparative Examples are sorted out, and the specific data are shown 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] It can be seen from the data of the embodiments and comparative examples in Table 8 that when the metal Nb precursor provided by the present invention is used for thin film deposition, the impurity C content in the film is less than that in the comparative example; it can be seen from Example 7 and Comparative Example 3 that although the impurity N content in the film prepared in Comparative Example 3 is less than that in Example 7, the impurity C content is significantly higher than that in Example 7, which 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, the description with reference to the terms "one embodiment", "example", "specific example", etc. means that the specific features, structures, materials or characteristics described in conjunction with the embodiment or example are included in at least one embodiment or example of the present invention. In this specification, the schematic representation of the above terms does not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any one or more embodiments or examples in a suitable manner.

[0208] The above shows and describes 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, and the above embodiments and descriptions are only for explaining the principles of the present invention. Without departing from the spirit and scope of the present invention, the present invention may have various changes and improvements, and these changes and improvements all fall within the scope of the present invention to be protected.

Claims

1. A Nb precursor, characterized in that: The chemical structure of the Nb precursor is represented by chemical formula (I): Chemical formula (Ⅰ) M(NR0)[XCR1R2(CR3R4) a QR5R6]3; Wherein, M is Nb; X is selected from O or S; Q is selected from N or P; R0 is selected from C1-C5 alkyl; R1-R6 are each independently selected from H, C1-C8 alkyl or C1-C5 alkoxy, and R1, R2, R3, and R4 are not H at the same time; a is an integer ≥0.

2. A Nb precursor according to claim 1, characterized in that: R0 is a C3-C5 alkyl group.

3. A Nb precursor according to claim 1, characterized in that: R1-R6 are independently selected from H, C1-C8 alkyl, and R1, R2, R3, R4 are not H at the same time; and / or a is an integer ≥1.

4. A Nb precursor according to claim 1, characterized in that: R5 and R6 are each independently selected from methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl or hexyl.

5. A Nb precursor according to claim 1, characterized in that: R0 is any one of n-propyl, isopropyl, n-butyl, isobutyl and tert-butyl.

6. The Nb precursor according to claim 1, characterized in that: The Nb precursor represented by the chemical formula (I) is represented by any one of the following chemical formulas (1-1) to (1-2): Chemical formula (1-1) Nb(NR0)[OCR1R2(CR3R4) a NR5R6]3; Chemical formula (1-2) Nb(NR0)[SCR1R2(CR3R4) a NR5R6]3; In the chemical formulae (1-1) to (1-2), R0, R1, R2, R3, R4, R5, R6, and a are each as defined in claim 1.

7. A method for preparing a Nb precursor according to any one of claims 1 to 6, characterized in that: The preparation method comprises the following steps: in an inert gas protection atmosphere, M(NR0)(NR2)3 and a solvent are mixed and cooled to below 0°C, and then a ligand HXCR1R2(CR3R4) is added. a QR5R6 is reacted, and after the reaction is completed, low-boiling substances are removed to obtain a crude Nb precursor. The crude Nb precursor is purified to prepare a Nb precursor.

8. The method for preparing a Nb precursor according to claim 7, characterized in that: The solvent is one or more of n-hexane, n-pentane, toluene, xylene, trimethylbenzene, ether, tetrahydrofuran, ethylene glycol dimethyl ether, and methyl tert-butyl ether; The M(NR0)(NR2)3 and HXCR1R2(CR3R4) a The molar ratio of QR5R6 is 1:1-5.

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

10. The method for using a Nb precursor in thin film deposition according to claim 9, characterized in that: During the deposition process, the deposition temperature is 250-400°C.

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