A Group IVB element precursor and its application in thin film deposition

Abstract

The present invention provides a precursor of a group IVB element and its application in thin film deposition. The structure of the precursor of the group IVB element is: L-M-(NR'R") x [O‑(CR1R2‑CR3R4) n ‑NR5R6] y The Group IVB element precursor of the present invention can improve the stability of the precursor source, can broaden the ALD window, meet the deposition requirements of higher temperatures, and can improve the film quality of the prepared thin film.

Description

Technical Field

[0001] The invention belongs to the technical field of thin film deposition, and relates to a group IVB element precursor and application thereof in thin film deposition. Background Art

[0002] In order to cope with the development trend of miniaturization of semiconductor equipment, high dielectric constant materials (high-k) are needed in semiconductor manufacturing processes to meet performance requirements such as high capacitance, low leakage current, and low power. Among high-k films, oxide films containing Group IVB elements such as titanium, zirconium, and hafnium are widely used in the structure of dynamic random access memory (DRAM), metal-oxide-semiconductor field effect transistor (MOSFET) and other devices because of their relatively high compatibility, wide bandgap energy, high refractive index, and thermal stability.

[0003] CN117396487A discloses a hafnium compound, a hafnium precursor composition containing the hafnium compound, a hafnium-containing film containing the hafnium compound or the hafnium precursor composition, and a method for manufacturing the same. The patent discloses a novel hafnium compound structure, which includes a central atom Hf, a substituted cyclopentadiene ligand bonded to Hf, and a substituted or unsubstituted amino ligand bonded to Hf. The film formed by the novel hafnium compound has improved GPC, uniformity, flatness, purity, etc. US9941114B2 discloses an organic metal precursor having a structure of X n (M)(R1) m (R2) k , wherein M is a central metal and may be one of zirconium, hafnium and titanium, X is a ligand of M and may include one of 6,6-dimethylfulvenyl, indenyl, cyclopentadienyl and cyclopentadienyl substituted with an amino group, R1 and R2 are ligands of M and are each independently an amino group or an ethylenediamino group, which can also form a uniform thin layer when deposited in an opening with a high aspect ratio.

[0004] However, existing precursors of Group IVB elements still have problems such as poor thermal stability, low film-forming temperature, and poor step coverage, which limit their practical applications and the performance of thin films. Summary of the invention

[0005] In view of the shortcomings of the prior art, the purpose of the present invention is to provide a precursor of a group IVB element and its application in thin film deposition. The precursor of the group IVB element of the present invention can improve the stability of the precursor source, can broaden the ALD window, meet the deposition requirements of higher temperatures, and can improve the film quality of the prepared thin film.

[0006] In order to achieve the purpose of the invention, the present invention adopts the following technical solutions:

[0007] In one aspect, the present invention provides a precursor of a Group IVB element, wherein the structure of the precursor of the Group IVB element is: LM-(N R'R") x [O-(CR1R2-CR3R4) n -NR5R6] y ;

[0008] Wherein, x is an integer of 0-2 (for example, 0, 1 or 2), y is an integer of 1-3 (for example, 1, 2 or 3), x+y=3, M is selected from any one of Ti, Zr, and Hf, and R1, R2, R3, and R4 are independently selected from any one of H, a C1-C6 alkyl group, a C1-C6 alkoxy group, a substituted amino group, and a silane group, and R', R", R5, and R6 are independently selected from H, a C1-C4 alkyl group, or R5 and R6 form a cyclic hydrocarbon structure, and n is an integer of 1-3 (for example, 1, 2, or 3).

[0009] In the present invention, the substituted amino group is preferably an amino group substituted with a C1-C10 (eg, C1, C2, C3, C4, C5, C6, C7, C8, C9 or C10) alkyl group.

[0010] In the present invention, the C1-C6 alkyl group may be a C1, C2, C3, C4, C5 or C6 alkyl group; the C1-C4 alkyl group may be a C1, C2, C3 or C4 alkyl group; the C1-C6 alkoxy group may be a C1, C2, C3, C4, C5 or C6 alkoxy group.

[0011] Further preferably, L is selected from at least one of a C5-C10 (e.g., C5, C6, C7, C8, C9 or C10) β-diketone compound, a C5-C10 (e.g., C5, C6, C7, C8, C9 or C10) diene compound, and a diazadiene (DAD) ligand.

[0012] Further preferably, the C5-C10 β-diketone compound includes but is not limited to any one of 2,4-pentanedione, tetramethylheptanedione, and fluorodimethyloctanedione; preferably 2,4-pentanedione.

[0013] Further preferably, the C5-C10 diene compound includes but is not limited to at least one of cyclopentadiene, substituted cyclopentadiene, cycloheptadiene, substituted cycloheptadiene, cyclononadiene, and substituted cyclononadiene; wherein the substituent in the substituted group is selected from C1-C5 alkyl, preferably, the C5-C10 diene compound is any one of cyclopentadiene and substituted cyclopentadiene.

[0014] Further preferably, the substituted cyclopentadiene includes but is not limited to any one, two or three substituted cyclopentadienes selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, isobutyl and tert-butyl.

[0015] In a preferred embodiment, the L is selected from a β-diketone compound or a C5-C10 diene compound.

[0016] In a more preferred embodiment, the L is selected from C5-C10 diene compounds.

[0017] More preferably, the L is selected from cyclopentadiene or substituted cyclopentadiene, and the substituent of the substituted cyclopentadiene is selected from C1-C5 alkyl.

[0018] Further preferably, R1, R2, R3, R4, R5 and R6 are independently selected from any one of H and C1-C6 alkyl.

[0019] Further preferably, the C1-C6 alkyl group is a straight chain alkyl group or a branched chain alkyl group, including but not limited to methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl, pentyl, isopentyl, tert-pentyl or hexyl.

[0020] In one embodiment, the R1 and R2 are methyl and ethyl respectively, and the R3 and R4 are H.

[0021] In one embodiment, the R1 and R3 are methyl and ethyl respectively, and the R2 and R4 are H.

[0022] In one embodiment, said R1 and R2 are methyl, and said R3 and R4 are H.

[0023] In one embodiment, the R1 and R2 are H, and the R3 and R4 are methyl and ethyl, respectively.

[0024] Further preferably, the C1-C4 alkyl group in the definition of R5 and R6 is methyl, ethyl, propyl, isopropyl or butyl.

[0025] Further preferably, when R5 and R6 form a cyclic hydrocarbon structure, the NR5R6 structure is and any one of its substitution structures, the dotted line represents the connection site of the group; wherein the substituent in the substitution structure is selected from at least one of C1-C5 alkyl, C1-C5 alkoxy, C1-C5 ester, halogen (-F, Cl, -Br, -I), and C1-C5 alkylcarbonyl;.

[0026] Preferably, R5 and R6 are independently selected from H or C1-C4 alkyl.

[0027] Preferably, said R' and R" are independently selected from C1-C4 alkyl groups.

[0028] More preferably, n is 1 or 2, more preferably 1.

[0029] Furthermore, the precursor structure containing group IVB elements may include:

[0030]

[0031]

[0032]

[0033] In the above structure, M is selected from any one of Ti, Zr and Hf, more preferably Hf; i Pr is isopropyl, n Pr is n-propyl.

[0034] On the other hand, the present invention provides a method for preparing the above-mentioned Group IVB element precursor, the preparation method comprising the following steps:

[0035] The raw materials LM-(NR'R")3 and HO-(CR1R2-CR3R4) n -NR5R6 to obtain the IVB group element precursor, wherein R7 and R8 are independently selected from H, C1-15 straight chain or branched alkyl.

[0036] Preferably, the LM-(NR'R")3 and HO-(CR1R2-CR3R4) n The molar ratio of -NR5R6 is 1:0.1-3.5, for example 1:0.1, 1:0.5, 1:0.8, 1:1, 1:1.5, 1:1.8, 1:2, 1:2.5, 1:2.8, 1:3, 1:3.3 or 1:3.5.

[0037] Preferably, the reaction is carried out in a solvent, and the solvent includes at least one of an alkane solvent, an ether solvent, an aromatic hydrocarbon solvent or a ketone solvent.

[0038] Preferably, the alkane solvent is a C5-C8 straight-chain or branched alkane, such as n-pentane, n-hexane, heptane, octane, etc.

[0039] Preferably, the ether solvent includes but is not limited to at least one of tetrahydrofuran, dimethyl ether, ethyl ether, ethylene glycol dimethyl ether, methyl tert-butyl ether or diethylene glycol dimethyl ether.

[0040] Preferably, the aromatic hydrocarbon solvent includes but is not limited to at least one of benzene, toluene or xylene.

[0041] Preferably, the reaction is carried out at room temperature (15-35°C, for example 15°C, 18°C, 20°C, 25°C, 28°C, 30°C, 33°C or 35°C) and the reaction time is 2-24h, for example 2h, 5h, 8h, 10h, 13h, 15h, 18h, 20h, 22h or 24h.

[0042] Preferably, after the reaction is completed, concentration, filtration or distillation is performed.

[0043] Preferably, the distillation is selected from atmospheric distillation or reduced pressure distillation, preferably reduced pressure distillation.

[0044] In another aspect, the present invention provides a thin film, which is prepared using the above-mentioned Group IVB element precursor.

[0045] Preferably, the thin film is a thin film containing at least one of the elements Ti, Zr, and Hf, and the types of the thin film include but are not limited to oxide film, sulfide film, carbonization film, carbon oxide film, nitride film, nitride oxide film, carbonitride film, phosphide film or phosphorus oxide film.

[0046] Further preferably, the type of the thin film is any one of an oxide film, a carbonized film, a carbon oxide film, a nitride film, a nitride oxide film or a carbonitride film.

[0047] Further preferably, the film may be doped with other functional elements, such as at least one of Li, Na, Ru, Cs, Mg, Ca, Sr, Ba, V, Nb, Ta, Mn, Mo, W, Ru, Co, Ni, Cu, Zn, Al, Ga, Ge, Sn, In, Bi, La, Ce, Yb, B, Si, F, etc.

[0048] On the other hand, the present invention provides a method for preparing the thin film as described above, comprising the following steps: exposing a substrate to the Group IVB element precursor and reaction gas in sequence to deposit the thin film.

[0049] Preferably, the reaction gas includes but is not limited to at least one of an oxygen source, a nitrogen source, a silicon source, a carbon source, a boron source, and a hydrogen source; the oxygen source includes but is not limited to at least one of oxygen, water vapor, ozone, hydrogen peroxide, formic acid, acetic acid, anhydride, and oxygen plasma; the nitrogen source includes but is not limited to at least one of nitric oxide, nitrogen dioxide, hydrazine, NH3, and NF3 plasma; the silicon source includes but is not limited to at least one of silane, disilane, and trisilane; the carbon source includes but is not limited to at least one of C1-10 alkanes, C2-10 olefins, glucose, fructose, and furan furfural; the boron source includes but is not limited to at least one of diborane, butane, and boron trichloride; the hydrogen source includes but is not limited to at least one of hydrogen gas and hydrogen plasma.

[0050] Preferably, the deposition method of the thin film can be at least one of chemical vapor deposition (CVD), atomic layer deposition (ALD), cyclic chemical vapor deposition (CCVD), plasma enhanced atomic layer deposition (PEALD), and plasma enhanced chemical vapor deposition (PECVD).

[0051] Preferably, the deposition temperature is 250-500°C, such as 250°C, 280°C, 300°C, 350°C, 400°C, 450°C or 500°C.

[0052] In a preferred embodiment, the method for preparing the film comprises the following steps:

[0053] (1) introducing the Group IVB element precursor vapor into a deposition chamber to chemically adsorb it onto the substrate surface;

[0054] (2) removing the precursor that is not adsorbed by the substrate;

[0055] (3) A reaction gas is introduced into the deposition chamber to make it adsorb on the surface of the substrate and deposit to form the thin film.

[0056] Preferably, the introduction time of the precursor vapor in step (1) is 0.1-50 s, for example 0.1 s, 1 s, 3 s, 5 s, 10 s, 15 s, 20 s, 25 s, 30 s, 35 s, 40 s, 45 s or 50 s.

[0057] Preferably, the method for removing the precursor not adsorbed by the substrate in step (2) is to purge with an inert gas, and the inert gas is at least one of N2, Ar, He and Kr.

[0058] Preferably, the reaction gas is introduced into step (3) for a time of 0.1-50 s, for example 0.1 s, 1 s, 3 s, 5 s, 10 s, 15 s, 20 s, 25 s, 30 s, 35 s, 40 s, 45 s or 50 s.

[0059] Preferably, the steps (1) to (3) can be cycled for different times to achieve the target film thickness.

[0060] Compared with the prior art, the present invention has the following beneficial effects:

[0061] The IVB group element precursor of the present invention can improve the stability of the precursor source, can widen the ALD window, meet the deposition requirements of higher temperatures, and can improve the film quality of the prepared thin film, so that the deposited thin film has less C and N impurity content and lower surface roughness. BRIEF DESCRIPTION OF THE DRAWINGS

[0062] Figure 1 This is the TGA graph of the precursor prepared in Example 1.

[0063] Figure 2 This is the TGA diagram of the precursor prepared in Example 2.

[0064] Figure 3 This is the H NMR spectrum of the precursor prepared in Example 1.

[0065] Figure 4 This is the H NMR spectrum of the precursor prepared in Example 2.

[0066] Figure 5 This is the relationship diagram between the deposition temperature and GPC of the precursor prepared in Example 2.

[0067] Figure 6 This is the X-ray reflection pattern (XRR) of the film prepared in Example 6.

[0068] Figure 7 This is an atomic force microscope (AFM) image of the thin film prepared in Example 6.

[0069] Figure 8 These are SEM images of the precursor prepared in Example 2 formed into a film on a high aspect ratio substrate. The left image is the SEM image of the top film, and the right image is the SEM image of the bottom film. The scales in both images are 10 nm. DETAILED DESCRIPTION

[0070] The technical solution of the present invention is further described below by specific implementation methods. It should be understood by those skilled in the art that the embodiments are only to help understand the present invention and should not be regarded as specific limitations of the present invention.

[0071] Example 1

[0072] This embodiment provides a Group IVB element precursor, the structure of the precursor is:

[0073]

[0074] The preparation method of the precursor is as follows: 80g CpHf(NMe2)3 is dissolved in 200mL cyclohexane, 86.4g HOCMeEtCH2NMe2 is added thereto under stirring, and the mixture is reacted at room temperature for 12h, and then the reaction system is concentrated, distilled under reduced pressure, and purified to obtain 78.6g of a liquid product with a yield of 63.2%.

[0075] Figure 1 This is the TGA graph of the above precursor: As can be seen from the graph, the residual mass of the precursor is 0.68%.

[0076] Figure 3For the above precursor 1 H NMR (400 MHz, C6D6) chart, specific peaks are: δ 6.40 (s, 5H), 2.31 (s, 18H), 2.27 (d, 6H), 1.68 (m, 6H), 1.25 (s, 9H), 1.01 (t, 9H).

[0077] Example 2

[0078] This embodiment provides a Group IVB element precursor, the structure of the precursor is:

[0079]

[0080] The preparation method of the precursor is as follows: 80g CpHf(NMe2)3 is dissolved in 200mL cyclohexane, 27.9g HOCMeEtCH2NMe2 is added thereto under stirring, and the mixture is reacted at room temperature for 12h, and then the reaction system is concentrated, distilled under reduced pressure, and purified to obtain 47.6g of a liquid product with a yield of 54.3%.

[0081] Figure 2 This is the TGA graph of the above precursor: As can be seen from the graph, the residual mass of the precursor is 0.35%. Figure 4 For the above precursors 1 H NMR (400 MHz, C6D6) diagram, specific peaks are: δ 6.14, (s, 5H), 2.98 (d, 12H), 2.23 (s, 6H), 2.18 (d, 2H), 1.58 (m, 2H), 1.19 (s, 3H), 0.95 (t, 3H).

[0082] Example 3

[0083] This embodiment provides a precursor containing a Group IVB element, and the structure of the precursor is:

[0084]

[0085] The preparation method of the precursor is as follows: 15.0 g of CpHf(NMe2)3 is dissolved in 200 mL of cyclohexane, 21.6 g of HOCHMeCHEtNMe2 is added thereto under stirring, and the mixture is reacted at room temperature for 12 hours. After that, the reaction system is concentrated, distilled under reduced pressure, and purified to obtain 12.2 g of the product with a yield of 52.3%.

[0086] Example 4

[0087] This embodiment provides a precursor containing a Group IVB element, and the structure of the precursor is:

[0088]

[0089] The preparation method of the precursor is as follows: 15.0 g of CpZr(NMe2)3 is dissolved in 200 mL of cyclohexane, 21.6 g of HOCMeEtCH2NMe2 is added thereto under stirring, and the mixture is reacted at room temperature for 12 hours. After that, the reaction system is concentrated, distilled under reduced pressure, and purified to obtain 9.9 g of the product with a yield of 43.2%.

[0090] Example 5

[0091] This embodiment provides a precursor containing a Group IVB element, and the structure of the precursor is:

[0092]

[0093] The preparation method of the precursor is as follows: 12.7g CpTi(NMe2)3 is dissolved in 200mL cyclohexane, 33.7g HOCHMeCHMeNMe2 is added thereto under stirring, and the mixture is reacted at room temperature for 12h, and then the reaction system is concentrated, distilled under reduced pressure, and purified to obtain 6.1g of the product with a yield of 33.0%.

[0094] Example 6

[0095] This embodiment provides a precursor containing a Group IVB element, and the structure of the precursor is:

[0096]

[0097] The preparation method of the precursor is as follows: 130.0 g of CpHf(NEt2)3 is dissolved in 200 mL of cyclohexane, 37.1 g of HOCMeEtCH2NMe2 is added thereto under stirring, and the mixture is reacted at room temperature for 24 hours. After that, the reaction system is concentrated, distilled under reduced pressure, and purified to obtain 50.6 g of the product with a yield of 31.1%.

[0098] In the present invention, the precursors of Examples 1-6 were all subjected to deposition window tests, and their deposition temperatures could all reach 400°C; Figure 5 The figure shows the relationship between the deposition temperature and the deposition rate (GPC) of the precursor prepared in Example 2. It can be seen from the figure that the deposition window of the precursor is 300-400°C.

[0099] Example 7

[0100] This embodiment provides a precursor prepared using Example 2 The method for depositing a HfO2 thin film comprises the following steps:

[0101] (1) The source bottle of the hafnium precursor CpHf(NMe2)2(OC(Me)(Et)CH2NMe2) prepared and purified to a purity of 6N (content reaching 99.9999%) in Example 2 was heated to 110° C., the ALD valve was heated to 140° C., the precursor delivery pipeline was heated to 160° C., the ALD chamber temperature was heated to 400° C., and the ALD chamber was evacuated to 0.5 Pa;

[0102] (2) CpHf(NMe2)2(OC(Me)(Et)CH2NMe2) vapor is introduced into the ALD chamber through an inert gas (Ar gas) for 2 seconds, and the precursor vapor forms chemical adsorption on the substrate surface;

[0103] (3) The unadsorbed precursors and reaction byproducts were purged with inert gas (Ar gas) for 25 seconds;

[0104] (4) The reaction gas O3 is introduced into the ALD chamber through the carrier gas (Ar gas) for 5 s, with an O3 flow rate of 50 sccm and a concentration of 250 g / Nm 3 , O3 completely reacts with the hafnium precursor adsorbed on the substrate;

[0105] (5) using an inert gas (Ar gas) to purge the unreacted O3 and the reaction byproducts for 15 seconds, and depositing a single-layer HfO2 film on the substrate surface;

[0106] (6) Repeat steps (2)-(5) for 250 cycles to form a HfO2 film with a thickness of approximately 15.5 nm.

[0107] XPS elemental analysis shows that the impurity C content in the deposited metal HfO2 film is 0.95%, and the N content is 0.32%. The specific data are shown in Table 1 below; the test instrument model is: X-ray photoelectron spectrometer (Thermo 250xi), instrument manufacturer: Thermo Scientific.

[0108] Table 1

[0109] element HkDJ O1s C1s N1s O / Hf Element content / % 35.60 63.13 0.95 0.32 1.77

[0110] Figure 6 The XRR graph of the film shows that the density of the film is 9.70 g / cm 3 , thickness is 15.5nm. The XRR test instrument model is: high resolution thin film X-ray diffractometer (XPert 3 MRD), instrument manufacturer: Malvern Panalytical.

[0111] Figure 7The AFM analysis of the film shows that the surface roughness of the film is 0.673 nm. The AFM test instrument model is: atomic force microscope (Dimension Icon), instrument manufacturer: Bruker.

[0112] Figure 8 The film formation of the precursor prepared in Example 2 on a TiN substrate with a high aspect ratio (30:1) is shown in FIG. Figure 8 It can be seen that the bottom film thickness is 5.56nm, the top film thickness is 5.36nm, and the step coverage is 103.7%, indicating that the HfO2 film can grow uniformly on the high aspect ratio substrate and has excellent conformality. The TEM test instrument model is: high-resolution transmission electron microscope (JEM-2100Plus), instrument manufacturer: Japan Electronics.

[0113] Example 8

[0114] This embodiment provides a precursor prepared using Example 1. The method for depositing a HfO2 thin film comprises the following steps:

[0115] (1) The source bottle of the hafnium precursor CpHf(OC(Me)(Et)CH2NMe2)3 prepared and purified to a purity of 6N in Example 1 was heated to 150°C, the ALD valve was heated to 160°C, the precursor delivery pipeline was heated to 180°C, the ALD chamber temperature was heated to 400°C, and the ALD chamber was evacuated to 0.5 Pa;

[0116] (2) CpHf(OC(Me)(Et)CH2NMe2)3 vapor is introduced into the ALD chamber through an inert gas (He gas) for 3 seconds, and the precursor vapor forms chemical adsorption on the substrate surface;

[0117] (3) The unadsorbed precursors and reaction byproducts were purged with inert gas (He gas) for 25 s;

[0118] (4) The reaction gas O3 is introduced into the ALD chamber through the carrier gas (He gas). The introduction time is 5s, the O3 flow rate is 50sccm, and the concentration is 250g / Nm 3 , O3 completely reacts with the hafnium precursor adsorbed on the substrate;

[0119] (5) using an inert gas (He gas) to purge the unreacted O3 and the reaction byproducts for 15 seconds, and depositing a single-layer HfO2 film on the substrate surface;

[0120] (6) Repeat steps (2)-(5) for 500 cycles to form a HfO2 film with a thickness of 15.0 nm.

[0121] XPS elemental analysis shows that the impurity C content in the deposited metal HfO2 film is 1.02%, and the N content is 0.69%. The specific data are shown in Table 2 below.

[0122] Table 2

[0123]

[0124]

[0125] Example 9

[0126] This embodiment provides a precursor prepared using Example 4. The method for depositing a ZrO2 thin film comprises the following steps:

[0127] (1) The source bottle of the zirconium precursor CpZr(OC(Me)(Et)CH2NMe2)3 prepared and purified to a purity of 6N in Example 4 was heated to 140°C, the ALD valve was heated to 160°C, the precursor delivery pipeline was heated to 180°C, the ALD chamber temperature was heated to 400°C, and the ALD chamber was evacuated to 0.5 Pa;

[0128] (2) CpZr(OC(Me)(Et)CH2NMe2)3 vapor is introduced into the ALD chamber through an inert gas (Ar gas) for 3 seconds, and the precursor vapor forms chemical adsorption on the substrate surface;

[0129] (3) The unadsorbed precursors and reaction byproducts were purged with inert gas (Ar gas) for 25 seconds;

[0130] (4) The reaction gas O3 is introduced into the ALD chamber through the carrier gas (Ar gas) for 5 s, with an O3 flow rate of 50 sccm and a concentration of 250 g / Nm 3 , O3 completely reacts with the hafnium precursor adsorbed on the substrate;

[0131] (5) using an inert gas (Ar gas) to purge the unreacted O3 and the reaction by-products for 15 seconds, and depositing a single-layer ZrO2 film on the substrate surface;

[0132] (6) Repeat steps (2) to (5) for 500 cycles to form a ZrO2 film with a thickness of 17.5 nm.

[0133] XPS elemental analysis shows that in the deposited metal ZrO2 film, the impurity C content is 1.21%, and the N content is 0.51%. The specific data are shown in Table 3 below.

[0134] Table 3

[0135]

[0136] Example 10

[0137] This embodiment provides a precursor prepared using Example 6 The method for depositing a HfO2 thin film comprises the following steps:

[0138] (1) The source bottle of the hafnium precursor CpHf(OC(Me)(Et)CH2NMe2)2(NEt2) prepared and purified to a purity of 6N in Example 6 was heated to 140°C, the ALD valve was heated to 160°C, the precursor delivery pipeline was heated to 180°C, the ALD chamber temperature was heated to 400°C, and the ALD chamber was evacuated to 0.5 Pa;

[0139] (2) CpHf(OC(Me)(Et)CH2NMe2)2(NEt2) vapor is introduced into the ALD chamber through an inert gas (Ar gas) for 3 seconds, and the precursor vapor forms chemical adsorption on the substrate surface;

[0140] (3) The unadsorbed precursors and reaction byproducts were purged with inert gas (Ar gas) for 25 seconds;

[0141] (4) The reaction gas O3 is introduced into the ALD chamber through the carrier gas (Ar gas) for 5 s, with an O3 flow rate of 50 sccm and a concentration of 250 g / Nm 3 , O3 completely reacts with the hafnium precursor adsorbed on the substrate;

[0142] (5) using an inert gas (Ar gas) to purge the unreacted O3 and the reaction byproducts for 15 seconds, and depositing a single-layer HfO2 film on the substrate surface;

[0143] (6) Repeat steps (2)-(5) for 400 cycles to form a HfO2 film with a thickness of 16.0 nm.

[0144] XPS elemental analysis shows that the impurity C content in the deposited metal HfO2 film is 1.26%, and the N content is 0.53%. The specific data are shown in Table 4 below.

[0145] Table 4

[0146]

[0147] Comparative Example 1

[0148] This comparative example provides a method for depositing a HfO2 thin film using CpHf(NMe2)3 as a precursor, comprising the following steps:

[0149] (1) Heat the source bottle of the hafnium precursor CpHf(NMe2)3 to 100°C, heat the ALD valve to 140°C, heat the precursor delivery pipeline to 160°C, heat the ALD chamber temperature to 400°C, and evacuate the ALD chamber to 0.5 Pa;

[0150] (2) CpHf(NMe2)3 vapor is introduced into the ALD chamber through an inert gas carrier gas (Ar gas) for 2 seconds, and the precursor vapor forms chemical adsorption on the substrate surface;

[0151] (3) The unadsorbed precursors and reaction byproducts were purged with inert gas (Ar gas) for 25 seconds;

[0152] (4) The reaction gas O3 is introduced into the ALD chamber through the carrier gas (Ar gas) for 5 s, with an O3 flow rate of 50 sccm and a concentration of 250 g / Nm 3 , O3 completely reacts with the hafnium precursor adsorbed on the substrate;

[0153] (5) using an inert gas (Ar gas) to purge the unreacted O3 and the reaction byproducts for 15 seconds, and depositing a single-layer HfO2 film on the substrate surface;

[0154] (6) Repeat steps (2)-(5) for 250 cycles to form a HfO2 film with a thickness of 18.0 nm.

[0155] XPS elemental analysis shows that the impurity C content in the deposited metal HfO2 film is 3.23%, and the N content is 1.21%. The specific data are shown in Table 5 below.

[0156] Table 5

[0157] element HkDJ O1s C1s N1s O / Hf Element content / % 33.07 62.49 3.23 1.21 1.89

[0158] Comparative Example 2

[0159] This comparative example provides a method for depositing a HfO2 thin film using CpZr(NMe2)3 as a precursor, comprising the following steps:

[0160] (1) Heat the source bottle of the hafnium precursor CpZr(NMe2)3 to 100°C, heat the ALD valve to 140°C, heat the precursor delivery pipeline to 160°C, heat the ALD chamber temperature to 400°C, and evacuate the ALD chamber to 0.5 Pa;

[0161] (2) CpZr(NMe2)3 vapor is introduced into the ALD chamber through an inert gas carrier gas (Ar gas) for 2 seconds, and the precursor vapor forms chemical adsorption on the substrate surface;

[0162] (3) The unadsorbed precursors and reaction byproducts were purged with inert gas (Ar gas) for 25 seconds;

[0163] (4) The reaction gas O3 is introduced into the ALD chamber through the carrier gas (Ar gas) for 5 s, with an O3 flow rate of 50 sccm and a concentration of 250 g / Nm 3 , O3 completely reacts with the hafnium precursor adsorbed on the substrate;

[0164] (5) using an inert gas (Ar gas) to purge the unreacted O3 and the reaction by-products for 15 seconds, and depositing a single-layer ZrO2 film on the substrate surface;

[0165] (6) Repeat steps (2)-(5) for 250 cycles to form a HfO2 film with a thickness of 18.5 nm.

[0166] XPS elemental analysis shows that the impurity C content in the deposited metal ZrO2 film is 7.81%, and the N content is 5.68%. The specific data are shown in Table 6 below.

[0167] Table 6

[0168]

[0169]

[0170] The applicant declares that the present invention illustrates the precursor of the present invention and its application in thin film deposition through the above-mentioned embodiments, but the present invention is not limited to the above-mentioned embodiments, that is, it does not mean that the present invention must rely on the above-mentioned embodiments to be implemented. Those skilled in the art should understand that any improvement of the present invention, equivalent replacement of the raw materials selected by the present invention, addition of auxiliary components, selection of specific methods, etc., all fall within the protection scope and disclosure scope of the present invention.

Claims

1. A precursor of a Group IVB element, characterized in that: The structure of the IVB group element precursor is: LM-(NR'R") x [O-(CR1R2-CR3R4) n -NR5R6] y ; Wherein, x is an integer of 0-2, y is an integer of 1-3, x+y=3, M is selected from any one of Ti, Zr, and Hf, the L is selected from at least one of a C5-C10 β-diketone compound, a C5-C10 diene compound, and a diazadiene ligand, the R1, R2, R3, and R4 are independently selected from any one of H, a C1-C6 alkyl group, a C1-C6 alkoxy group, a substituted amino group, and a silane group, the R', R", R5, and R6 are independently selected from H, a C1-C4 alkyl group, or R5 and R6 form a cyclic hydrocarbon structure, and n is an integer of 1-3.

2. The Group IVB element precursor according to claim 1, characterized in that: The C5-C10 β-diketone compound includes any one of 2,4-pentanedione, tetramethylheptanedione, and fluorodimethyloctanedione; preferably 2,4-pentanedione; Preferably, the C5-C10 diene compound includes at least one of cyclopentadiene, substituted cyclopentadiene, cycloheptadiene, substituted cycloheptadiene, cyclononadiene, and substituted cyclononadiene; wherein the substituent in the substituted group is selected from C1-C5 alkyl; Preferably, the C5-C10 diene compound is any one of cyclopentadiene or substituted cyclopentadiene, wherein the substituent in the substituted group is selected from C1-C5 alkyl; Preferably, the substituted cyclopentadiene includes any one, two or three substituted cyclopentadienes selected from the group consisting of methyl, ethyl, propyl, isopropyl, butyl, isobutyl and tert-butyl.

3. The Group IVB element precursor according to claim 1 or 2, characterized in that: The R1, R2, R3, R4, R5 and R6 are independently selected from any one of H and C1-C6 alkyl; Preferably, R1 and R2 are methyl and ethyl respectively, and R3 and R4 are H; Preferably, R1 and R3 are methyl and ethyl respectively, and R2 and R4 are H; Preferably, R1 and R2 are methyl, and R3 and R4 are H; Preferably, R1 and R2 are H, and R3 and R4 are methyl and ethyl, respectively.

4. The Group IVB element precursor according to any one of claims 1 to 3, characterized in that: When R5 and R6 form a cyclic hydrocarbon structure, the NR5R6 structure is and any one of its substituted structures, wherein the dotted line represents the attachment site of the group; wherein the substituent in the substituted structure is selected from at least one of C1-C5 alkyl, C1-C5 alkoxy, C1-C5 ester, halogen, and C1-C5 alkylcarbonyl; Preferably, said R5 and R6 are independently selected from H or C1-C4 alkyl; Preferably, said R' and R" are independently selected from C1-C4 alkyl; More preferably, n is 1 or 2, more preferably 1.

5. The Group IVB element precursor according to any one of claims 1 to 4, characterized in that: The precursor containing Group IVB elements is any one of the following compounds: In the above structure, M is selected from any one of Ti, Zr and Hf, more preferably Hf. i Pr is isopropyl, n Pr is n-propyl.

6. The method for preparing a precursor of a Group IVB element according to any one of claims 1 to 5, characterized in that: The preparation method comprises the following steps: The raw materials LM-(NR'R")3 and HO-(CR1R2-CR3R4) n -NR5R6 to obtain the IVB group element precursor.

7. The preparation method according to claim 6, characterized in that: The LM-(N R'R")3 and HO-(CR1R2-CR3R4) n -The molar ratio of NR5R6 is 1:0.1-3.5; Preferably, the reaction is carried out in a solvent, and the solvent includes at least one of an alkane solvent, an ether solvent, an aromatic hydrocarbon solvent or a ketone solvent; Preferably, the alkane solvent is a C5-C8 straight-chain or branched alkane, preferably at least one of n-pentane, n-hexane, heptane or octane; Preferably, the ether solvent includes at least one of tetrahydrofuran, dimethyl ether, ethyl ether, ethylene glycol dimethyl ether, methyl tert-butyl ether or diethylene glycol dimethyl ether; Preferably, the aromatic hydrocarbon solvent includes at least one of benzene, toluene or xylene; Preferably, the reaction is carried out at room temperature for 2-24 hours; Preferably, after the reaction is completed, concentration, filtration or distillation is performed; Preferably, the distillation is selected from atmospheric distillation or reduced pressure distillation, preferably reduced pressure distillation.

8. A film, characterized in that: The film is prepared using the Group IVB element precursor as claimed in any one of claims 1 to 5.

9. A method for preparing a thin film according to claim 8, characterized in that: The method for preparing the thin film comprises the following steps: exposing a substrate to the precursor of the IVB group element and the reaction gas in sequence for deposition to form the thin film.

10. The method for preparing a thin film according to claim 9, characterized in that: The reaction gas includes at least one of an oxygen source, a nitrogen source, a silicon source, a carbon source, a boron source, and a hydrogen source; Preferably, the oxygen source comprises at least one of oxygen, water vapor, ozone, hydrogen peroxide, formic acid, acetic acid, acid anhydride or oxygen plasma; Preferably, the nitrogen source comprises at least one of nitric oxide, nitrogen dioxide, hydrazine, NH3 or NF3 plasma; Preferably, the silicon source comprises at least one of silane, disilane or trisilane; Preferably, the carbon source comprises at least one of C1-10 alkanes, C2-10 alkenes, glucose, fructose or furan furfural; Preferably, the boron source includes at least one of diborane, tetraborane or boron trichloride; the hydrogen source includes at least one of hydrogen gas and hydrogen plasma; Preferably, the thin film may be deposited by at least one of chemical vapor deposition, atomic layer deposition, cyclic chemical vapor deposition, plasma enhanced atomic layer deposition, and plasma enhanced chemical vapor deposition; Preferably, the deposition temperature is 250-500°C.

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