A cobalt-containing complex and its preparation method and application

Abstract

The present invention discloses a cobalt-containing complex, the structural formula of which is selected from any one of the following formulas (1), (2), (3), and (4). The cobalt-containing complex has thermal stability, electrical conductivity, ductility, and film-forming properties that meet technical requirements, can be used as a precursor in ALD or CVD processes, and has broad application prospects.

Description

Technical Field

[0001] The present invention belongs to the field of organometallic precursor materials, and in particular relates to a cobalt-containing complex and a preparation method and application thereof. Background Art

[0002] Atomic layer deposition (ALD) technology uses gaseous reactants. By controlling the gas path system, gaseous reactants (i.e., precursors) are alternately introduced into the reaction chamber, chemically adsorbed on the substrate surface, and reacted to form a deposited film. Atomic layer deposition technology has the advantages of good bonding strength, layer-by-layer deposition, consistent film thickness, and good composition uniformity. It is an advanced nano-surface treatment technology. As an extremely precise and controllable process for manufacturing thin films, it is being used in more and more scenarios. Together with its etching counterpart—atomic layer etching (ALE)—ALD enables new materials and three-dimensional designs to be used in advanced chip manufacturing.

[0003] However, this technology faces new challenges as real-world production demands arise, with numerous factors influencing it. For example, the precursor material must maintain a certain level of thermal stability while maintaining volatility. Furthermore, adsorption, reactivity, and substrate etching are also important considerations. Therefore, the secret to achieving improved control over processes like selective growth lies in dividing the deposition process into half reactions, each of which can be well controlled. The ALD process begins by injecting a precursor into the reaction chamber, which coats (or "adsorbs") the exposed surfaces of the wafer. This process is known as self-limiting because the precursor can only adsorb on exposed areas; once all of these are covered, adsorption ceases. A second gas is then introduced and reacts with the precursor to form the desired material. This second step is also self-limiting: once the available precursor sites are exhausted, the reaction ceases. These two steps are repeated until the desired film thickness is achieved.

[0004] Furthermore, with the rapid advancement of industries like smartphones and photovoltaic semiconductors, the use of ALD continues to grow. For example, one promising application is selective area deposition, which exploits the inherent selectivity of thin films. Researchers are currently developing methods to deposit metals and dielectrics in very specific locations—essentially creating a different patterning approach. For the first time, selectivity has become the most important thin film property, crucial for integration at the 5nm to 3nm technology nodes. ALD is also being explored as a method to improve overlay control, or how precisely a new pattern can be aligned with an existing pattern. Any offset or misalignment with the underlying electrical contacts can reduce conductivity and negatively impact chip performance. As these and other applications develop, we expect atomic layer processing to play an increasingly important role in advancing semiconductor manufacturing. ALD has proven to be a key enabling technology, and as they are integrated into next-generation devices, the development of ALD deposition materials and reforms in ALD deposition techniques are urgent and important. Summary of the Invention

[0005] Based on the above technical problems, the present invention provides an ALD precursor material - a cobalt-containing complex with a cyclopentadienyl structure, which solves the problems of limited types and poor overall performance of current cobalt-containing complex precursors.

[0006] The specific scheme of the present invention is as follows:

[0007] One of the objects of the present invention is to provide a cobalt-containing complex, the structural formula of which is selected from any one of the following formulas (1), (2), (3), and (4);

[0008]

[0009] Among them, R and R 1 Each is independently selected from any one of the following structures;

[0010]

[0011] X 1 and X 2 Each is independently selected from any one of H, C, N, O, S, P, F, Cl, Br, I, CO, and MeCN; n is selected from any one of 0, 1, 2, 3, 4, and 5.

[0012] Preferably, the cobalt-containing complex has the structural formula

[0013] The second object of the present invention is to provide a method for preparing the cobalt-containing complex, comprising: (1) dissolving dicobalt octacarbonyl in an anhydrous organic solvent, adding pentamethylcyclopentadiene, and reacting at 40-80° C. for 6-8 hours; (2) cooling the reaction solution to room temperature, adding an alkaline substance to the reaction solution, and then adding a nucleophilic reagent or an electrophilic reagent to react; (3) filtering, concentrating, and recrystallizing to obtain the cobalt-containing complex; wherein the molar ratio of the dicobalt octacarbonyl, the alkaline substance, and the nucleophilic reagent or the electrophilic reagent is 1:1.8-2.2:1-1.2.

[0014] Preferably, the molar ratio of dicobalt octacarbonyl, the basic substance, and the nucleophile or electrophile is 1:2:1.

[0015] The present invention also provides another method for preparing a cobalt-containing complex, comprising: (1) dissolving dicobalt octacarbonyl in an anhydrous organic solvent, adding pentamethylcyclopentadiene, heating to 40-80° C., adding a halogenating agent, and reacting under white light irradiation for 2-10 hours; (2) cooling and recrystallizing; and (3) washing and drying the precipitated solid; wherein the molar ratio of the dicobalt octacarbonyl to the halogenating agent is 1:1-1.2.

[0016] Preferably, the alkaline substance is selected from at least one of cesium carbonate, potassium carbonate, sodium carbonate, sodium bicarbonate, potassium bicarbonate, sodium hydride, and sodium-potassium alloy.

[0017] Preferably, the nucleophile is an organometallic nucleophile; and the electrophile is an organohalide electrophile.

[0018] Preferably, the organic solvent in step (1) is selected from at least one of tetrahydrofuran, acetonitrile, benzonitrile, 1,2-dichloroethane, toluene, chlorobenzene, N,N-dimethylformamide, N,N-dimethylacetamide, and 1,4-dioxane.

[0019] Preferably, the solvent used in the washing or recrystallization step in the above preparation method is at least one selected from n-pentane, n-hexane, n-heptane, petroleum ether, methyl tert-butyl ether, diethyl ether, petroleum ether, cyclohexane, and cyclopentane.

[0020] The third object of the present invention is to provide the use of the cobalt-containing complex as a precursor in an ALD or CVD process.

[0021] Preferably, when used, the molar mass of the cobalt-containing complex is ≤500 g / mol.

[0022] Preferably, the cobalt-containing complex is used as a precursor material and deposited on the surface of a substrate using atomic layer deposition technology to obtain a cobalt-containing deposited film.

[0023] The atomic layer deposition method of the present invention is a conventional method, such as but not limited to the following methods:

[0024] (1) Under an inert argon atmosphere, a reducing gas reactant is first introduced to form a layer of reducing reactant on the surface of the substrate; (2) the processing chamber is flushed and / or evacuated with the inert argon gas multiple times; (3) a cobalt-containing precursor is reacted with the reducing reactant to form a layer of cobalt metal on the substrate, wherein the reaction occurs on the surface of the substrate and is optionally assisted by an electric current; (4) the processing chamber is flushed and / or evacuated with the inert argon gas multiple times, and the above process is repeated to achieve a suitable cobalt atomic layer;

[0025] Reducing reactants include, but are not limited to, hydrogen (H2), water (H2O), ammonia (NH3) / amines (R2NH), borane (BH3) / boron hydride (R2BH), silane (NH3) / silicon hydride (R3SiH), alcohols (R-OH), thiols (R-SH), and other reducing compounds. R represents, but is not limited to, a compound skeleton containing carbon, hydrogen, oxygen, or nitrogen. The reaction temperature is generally controlled between 50°C and 460°C, and the entire operation should be performed under an inert gas atmosphere such as argon.

[0026] The beneficial effects of the present invention are:

[0027] (1) The present invention provides an ALD precursor - a cobalt-containing complex with a cyclopentadienyl structure, which solves the problem that the current cobalt-containing complex precursors are limited in variety and have poor overall performance; the thermal stability, conductivity, ductility, and film-forming properties of the cobalt-containing complex all meet technical requirements, and can be used as a key material for semiconductor substrate ALD and CVD manufacturing processes, and can also be used as an important raw material for self-aligned patterning, 3d NAND, FinFET and other technical applications; especially in the development of chip integration processes, the development of materials with good ductility, volatility, conductivity, thermal stability, and film-forming properties is a key technical node for achieving 5nm to 3nm chips, and has a relatively broad application expansion space;

[0028] (2) The present invention also provides a method for preparing the cobalt-containing complex. The raw materials of the present invention are relatively easy to obtain, and batch synthesis can be achieved through relatively simple chemical reactions. It has the advantages of simple operation, concise steps, high atomic utilization rate, relatively stable chemical properties, low cost, and easy purification. BRIEF DESCRIPTION OF THE DRAWINGS

[0029] Figure 1 This is a physical picture of cyclopentadienylcarbonylcobalt dibromide CpCoBr2(CO) prepared in Example 1;

[0030] Figure 2 This is a physical picture of cyclopentadienyl allylcarbonyl cobalt bromide CpCoC3H5(CO)Br prepared in Example 2;

[0031] Figure 3 This is a photo of the film formation of cyclopentadienyl allylcarbonyl cobalt bromide CpCoC3H5(CO)Br prepared in Example 2; DETAILED DESCRIPTION

[0032] Hereinafter, the technical solutions of the present invention will be described in detail through specific embodiments. However, it should be clearly stated that these embodiments are provided for illustration only and are not to be construed as limiting the scope of the present invention.

[0033] All reaction raw materials and solvents in the following examples are J&K reagent products.

[0034] Example 1

[0035] A cobalt-containing complex, cyclopentadienylcarbonylcobalt dibromide CpCoBr2(CO), has the following structural formula:

[0036]

[0037] The preparation method thereof comprises:

[0038] (1) Dissolve dicobalt octacarbonyl in anhydrous toluene, add pentamethylcyclopentadiene, heat to 80°C, add carbon tetrabromide, and react under white light irradiation for 8 hours, until the color gradually turns yellow-brown; wherein the molar ratio of dicobalt octacarbonyl to carbon tetrabromide is 1:1;

[0039] (2) The reaction system was taken out and cooled to room temperature. Then, an appropriate amount of n-pentane was added to the system. The reaction solution was stirred at low temperature to gradually precipitate a yellow-brown solid product.

[0040] (3) The mixed solution was filtered and the solid was collected, and n-pentane was added for washing for multiple times, and finally the solid was vacuum dried.

[0041] The cyclopentadienylcarbonyl cobalt dibromide obtained in this example is a yellow-brown solid, as shown in the figure below. Figure 1 As shown, 1 HNMR(500MHz,DMSO-d3)δ5.52(s,5H).

[0042] Example 2

[0043] A cobalt-containing complex, cyclopentadienyl allylcarbonyl cobalt bromide CpCoC3H5(CO)Br, has the following structural formula:

[0044]

[0045] The preparation method thereof comprises:

[0046] (1) dissolving the octacarbonyl dicobalt raw material in anhydrous tetrahydrofuran, adding pentamethylcyclopentadiene, heating to 60°C, and stirring for 6 hours; (2) cooling the reaction solution to room temperature, adding Na2CO3 to the reaction solution, adding allyl bromide, and continuing to stir until the reaction is complete; (3) filtering the reaction solution from the previous step, collecting the filtrate, concentrating, and recrystallizing to obtain; wherein the molar ratio of the added octacarbonyl dicobalt, Na2CO3, and allyl bromide is 1:2:1.

[0047] The cyclopentadienyl allyl carbonyl cobalt bromide obtained in this example is a yellow-brown solid, as shown in the figure below. Figure 2 As shown, 1 H NMR (500MHz, DMSO-d3) δ5.78-5.66 (m, 1H), δ5.45 (s, 5H). 5.06-4.89 (m, 2H), 1.86 (dd, J = 6.2, 1.2Hz, 2H).

[0048] Application Example 1

[0049] The cobalt-containing complexes obtained in Examples 1 and 2 were used as precursor materials, and a cobalt-containing deposition film was formed on the substrate surface using the Beneq TFS 200ALD atomic layer deposition equipment using atomic layer deposition technology. Figure 3 The specific method of atomic layer deposition includes: (1) firstly introducing reducing gas reactants under an inert argon atmosphere to form a layer of reducing reactants on the surface of the substrate (4 inches);

[0050] (2) flushing and / or evacuating the processing chamber with inert argon gas multiple times;

[0051] (3) reacting a cobalt-containing precursor with a reduced reactant to form a layer of cobalt metal on the substrate, wherein the reaction occurs on the surface of the substrate and is optionally assisted by an electric current;

[0052] (4) flushing and / or evacuating the processing chamber with inert argon gas multiple times, repeating the above process to achieve a suitable cobalt atomic layer;

[0053] The reaction temperature is controlled at 350°C, the vacuum degree is controlled at 1 MPa, and the entire operation should be carried out in an inert gas atmosphere such as argon.

[0054] The conductivity of the film-formed samples was tested at room temperature and after annealing at 400°C using the Wheatstone single bridge method. The test results are shown in Table 1 below.

[0055] Table 1. Conductivity test results

[0056]

[0057] It can be seen that the film conductivity can be controlled within 10 5 -10 11 The conductivity is within the range of Ω·CM, and after high-temperature annealing at 300-450℃, the conductivity number is less than one order of magnitude. The film has excellent thermal stability and good ductility.

[0058] The above description is only a preferred specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any technician familiar with the technical field, within the technical scope disclosed by the present invention, who makes equivalent replacements or changes based on the technical solution and inventive concept of the present invention, should be covered by the scope of protection of the present invention.

Claims

1. A cobalt-containing complex, characterized in that Its structural formula is shown in the following formula (1); （1）； Wherein, R is selected from any one of the following structures; ； ； R 1 is H; X 1 and X 2 Each is independently selected from any one of F, Cl, Br, I, CO, and MeCN; n is selected from any one of 0, 1, 2, 3, 4, and 5; The cobalt-containing complex does not include .

2. The cobalt-containing complex according to claim 1, characterized in that The structural formula of the cobalt-containing complex is .

3. The method for preparing the cobalt-containing complex according to claim 1 or 2, characterized in that: include: (1) dissolving dicobalt octacarbonyl in an anhydrous organic solvent, adding cyclopentadiene, and reacting at 40-80° C. for 6-8 hours; (2) cooling the reaction solution to room temperature, adding an alkaline substance to the reaction solution, and then adding a nucleophilic reagent or an electrophilic reagent to react; (3) filtering, concentrating, and recrystallizing to obtain; wherein the molar ratio of dicobalt octacarbonyl, the alkaline substance, and the nucleophilic or electrophilic reagent is 1:1.8-2.2:1-1.

2.

4. The method for preparing the cobalt-containing complex according to claim 3, characterized in that: The molar ratio of octacarbonyl dicobalt, the alkaline substance, and the nucleophilic or electrophilic reagent is 1:2:

1.

5. The method for preparing a cobalt-containing complex according to claim 1 or 2, characterized in that: include: (1) dissolving dicobalt octacarbonyl in an anhydrous organic solvent, adding cyclopentadiene, heating to 40-80°C, adding a halogenating agent, and reacting under white light irradiation for 2-10 hours; (2) cooling and recrystallization; (3) washing the precipitated solid and drying to obtain; wherein the molar ratio of the dicobalt octacarbonyl to the halogenating agent is 1:1-1.

2.

6. The method for preparing a cobalt-containing complex according to claim 3, wherein The alkaline substance is selected from at least one of cesium carbonate, potassium carbonate, sodium carbonate, sodium bicarbonate, potassium bicarbonate, sodium hydride, and sodium-potassium alloy.

7. The method for preparing a cobalt-containing complex according to claim 3 or 6, characterized in that: The nucleophile is an organometallic nucleophile; the electrophile is an organohalide electrophile.

8. The method for preparing a cobalt-containing complex according to claim 3 or 5, characterized in that: The organic solvent in step (1) is selected from at least one of tetrahydrofuran, acetonitrile, benzonitrile, 1,2-dichloroethane, toluene, chlorobenzene, N,N-dimethylformamide, N,N-dimethylacetamide, and 1,4-dioxane.

9. Use of the cobalt-containing complex according to claim 1 or 2, or the cobalt-containing complex prepared by the method according to any one of claims 3 to 8, as a precursor in an ALD or CVD process.

10. The use according to claim 9, characterized in that The molar mass of the cobalt-containing complex is ≤500 g / mol.

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