A tungsten-containing complex and its preparation method and application
By preparing tungsten-containing complexes with celocene-based structures, the problems of limited species and insufficient performance of tungsten-containing complexes in the prior art are solved, and high-precision ALD process application is achieved, and the accuracy and efficiency of semiconductor manufacturing are improved.
Patent Information
- Application Number
- CN202310978622.0
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-08-04
- Publication Date
- 2025-08-12
- Estimated Expiration
- 2043-08-04
AI Technical Summary
The existing tungsten-containing complex precursors have limited types and poor comprehensive performance, which is difficult to meet the requirements of ALD process for thermal stability, volatility and film formation, affecting the accuracy and efficiency of semiconductor manufacturing.
It provides a tungsten-containing complex with a celocene structure, which is prepared by a specific chemical reaction, has good thermal stability, conductivity and film formation, and is suitable for ALD and CVD processes.
High precision selective deposition and patterning in semiconductor manufacturing is achieved, improving the reliability and efficiency of chip integration processes, especially key applications in the 5nm to 3nm technology nodes.
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Figure CN117050117B_ABST
Abstract
Description
Technical Field
[0001] The present invention belongs to the field of organometallic precursor materials, and in particular relates to a tungsten-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 tungsten-containing complex with a cyclopentadienyl structure, which solves the problems of limited types and poor overall performance of current tungsten-containing complex precursors.
[0006] The specific scheme of the present invention is as follows:
[0007] The present invention provides a tungsten-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 independently represents any one of the following structures;
[0010]
[0011] X is selected from any one of H, C, N, O, S, P, F, Cl, Br, I, CO, and MeCN;
[0012] Y is selected from any one of C, N, O, and P; n is selected from any one of 0, 1, 2, 3, 4, and 5;
[0013] Alkyl represents a functional group with no more than six carbon atoms;
[0014] R 0 Contains at least one substituent including H, C, N, O, F, Cl, Br, and I.
[0015] Preferably, the structural formula of the tungsten-containing complex is
[0016] The present invention also provides a method for preparing the tungsten-containing complex, comprising: (1) dissolving a metallic tungsten raw material in an anhydrous organic solvent, adding an alkaline substance, and reacting at 40-80° C. for 1-2 hours; (2) cooling the reaction solution to room temperature, and then adding a nucleophilic or electrophilic reagent thereto for complete reaction; (3) filtering, concentrating, and recrystallizing to obtain the complex; the molar ratio of the metallic tungsten raw material, the alkaline substance, and the nucleophilic or electrophilic reagent is 1:1.5-3:1-3; preferably, the molar ratio of the metallic tungsten raw material, the alkaline substance, and the nucleophilic or electrophilic reagent is 1:2:1.
[0017] Preferably, the alkaline substance is selected from one or more combinations of cesium carbonate, potassium carbonate, sodium carbonate, sodium bicarbonate, potassium bicarbonate, sodium hydride, and sodium-potassium alloy.
[0018] Preferably, the nucleophile is an organometallic nucleophile; and the electrophile is an organohalide electrophile.
[0019] The present invention also provides another method for preparing a tungsten-containing complex, comprising: (1) dissolving a metallic tungsten raw material in an anhydrous organic solvent, adding a halogenating agent, heating to 40-80° C., and irradiating with white light for a reaction of 2-10 hours; (2) cooling and recrystallizing; and (3) washing and drying the precipitated solid; wherein the molar ratio of the metallic tungsten raw material to the halogenating agent is 1:1-3.
[0020] Preferably, the metal tungsten raw material is selected from any one of cyclopentadienyl tungsten polymer, tungsten cyclopentadienyl chloride, cyclohexadienyl tungsten polymer, and cyclooctatetraenyl tungsten polymer.
[0021] Preferably, the organic solvents are selected from one or more combinations of tetrahydrofuran, acetonitrile, benzonitrile, 1,2-dichloroethane, toluene, chlorobenzene, N,N-dimethylformamide, N,N-dimethylacetamide, and 1,4-dioxane.
[0022] The tungsten-containing complex of the present invention is used as a precursor in an ALD or CVD process.
[0023] Preferably, when used, the molar mass of the tungsten-containing complex is ≤500 g / mol.
[0024] Preferably, the tungsten-containing complex is used as a precursor material and is deposited on the surface of a substrate using an atomic layer deposition technique to obtain a tungsten-containing deposited film.
[0025] The atomic layer deposition method of the present invention is a conventional method, such as but not limited to the following methods:
[0026] (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 tungsten-containing precursor is reacted with the reducing reactant to form a layer of tungsten metal on the substrate, wherein the reaction occurs on the surface of the substrate and is optionally assisted by 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 tungsten electron layer;
[0027] Reducing reactants include, but are not limited to, hydrogen (H2), water (H2O), ammonia (NH3) / amine (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 carried out in an inert gas atmosphere such as argon; the vacuum level should be controlled between -1MPa and 1MPa.
[0028] The beneficial effects of the present invention are:
[0029] (1) The present invention provides an ALD precursor - a tungsten-containing complex with a cyclopentadienyl structure, which solves the problem that the current tungsten-containing complex precursors are limited in variety and have poor overall performance; the thermal stability, conductivity, ductility, and film-forming properties of the tungsten-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;
[0030] (2) The present invention also provides a method for preparing the tungsten-containing complex, the raw materials of which are relatively easy to obtain, and batch synthesis can be achieved using relatively simple chemical reactions. It has the advantages of simple operation, concise steps, high atomic utilization, relatively stable chemical properties, low cost, and easy purification. BRIEF DESCRIPTION OF THE DRAWINGS
[0031] Figure 1 This is a physical picture of cyclopentadienyldicarbonyl tungsten bromide CpWBr(CO)2 prepared in Example 1;
[0032] Figure 2 This is a physical picture of cyclopentadienyl allyl tungsten dicarbonyl CpWC3H6(CO)2 prepared in Example 2;
[0033] Figure 3 The thermal stability test results of cyclopentadienyl allyl tungsten dicarbonyl CpWC3H6(CO)2 prepared in Example 2;
[0034] Figure 4 Volatility test results of cyclopentadienyl allyl tungsten dicarbonyl CpWC3H6(CO)2 prepared in Example 2;
[0035] Figure 5 This is a photo of the film formation of cyclopentadienyl allyl tungsten dicarbonyl CpWC3H6(CO)2 prepared in Example 2;
[0036] Figure 6 The conductivity test results of the cyclopentadienyl allyl tungsten dicarbonyl film sample prepared in Example 2; DETAILED DESCRIPTION
[0037] 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.
[0038] All reaction raw materials and solvents in the following examples are J&K reagent products.
[0039] Example 1
[0040] A tungsten-containing complex, cyclopentadienyldicarbonyltungsten bromide CpWBr(CO)2, has the following structural formula:
[0041]
[0042] The preparation method thereof comprises:
[0043] (1) Dissolve (Cp)2(CO)4W (biscyclopentadienyltungsten tetracarbonyl) in anhydrous toluene, add carbon tetrabromide, heat to 80°C, and irradiate with 26W white light. Stir the reaction for 8 hours. After the reaction is completed, the color gradually turns dark brown. (2) Take out the reaction system, cool to room temperature, then add an appropriate amount of n-pentane to the system, place the reaction solution at low temperature and stir, and gradually precipitate a dark brown solid product. (3) Filter the above mixed solution and collect the solid, add n-pentane to wash it several times, and finally vacuum dry the solid to obtain the product. The molar ratio of (Cp)2(CO)4W to carbon tetrabromide is 1:1.
[0044] The cyclopentadienyl dicarbonyl tungsten bromide obtained in this example is a dark brown solid. Figure 1 As shown, 1 HNMR(500MHz,DMSO-d3)δ5.52(s,5H).
[0045] Example 2
[0046] A tungsten-containing complex, cyclopentadienyl allyl tungsten dicarbonyl CpWC3H6(CO)2, has the following structural formula:
[0047]
[0048] The preparation method thereof comprises:
[0049] (1) dissolving (Cp)2(CO)4W (biscyclopentadienyltetracarbonyltungsten) in anhydrous THF, adding sodium potassium alloy, heating to 60°C, and stirring the reaction for 2 hours; (2) cooling the reaction solution to room temperature, adding allyl chloride to the reaction solution, and continuing to stir until the reaction is complete; (3) filtering the reaction solution from the previous step, collecting the filtrate, concentrating it, and recrystallizing it to obtain the product; wherein the molar ratio of (Cp)2(CO)4W, sodium potassium alloy, and allyl chloride is 1:2:1.
[0050] The cyclopentadienyl allyl tungsten dicarbonyl obtained in this example is a liquid, and its physical form is shown in the figure below. Figure 2 As shown, 1H 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).
[0051] The properties of the cyclopentadienyl allyl tungsten dicarbonyl obtained in this example were tested, and the specific test methods and results are as follows:
[0052] (1) Thermal stability
[0053] Take 6mg sample and use Mettler TGA2 thermogravimetric analyzer to test, specifically: constant temperature at 30℃ for 30 minutes, program temperature increase from 30 to 600℃ at 10K / min, then naturally cool to room temperature, purge gas N2 at a flow rate of 50ml / min; the test results are as follows Figure 3 shown.
[0054] The figure shows a 5% mass loss at 160°C, skeleton fracture at 160-230°C, secondary weight loss at 230-400°C, and a stable mass of approximately 2.6 mg after 400°C. This analysis indicates that the tungsten metal complex has good thermal stability and meets the requirements of an atomic layer deposition precursor.
[0055] (2) Volatility
[0056] The samples were tested and analyzed using an HCR-1 differential scanning calorimeter. Specifically, the temperature was kept constant at 30°C for 30 minutes, the temperature was programmed from 30 to 500°C at 10K / min, and then naturally cooled to room temperature. The purge gas was N2 at a flow rate of 50ml / min. The test results are shown in the figure below. Figure 4 As shown;
[0057] Through DSC analysis and testing, it can be found that the sample has a strong absorption heat signal at about 160°C, indicating that the volatilization temperature of the metal tungsten complex is about 160°C. The metal tungsten complex has strong volatility and meets the requirements of atomic layer deposition precursor.
[0058] Application Example 1
[0059] Using the cyclopentadienyl allyl tungsten dicarbonyl CpWC3H6(CO)2 obtained in Example 2 as a precursor material, a tungsten-containing deposition film was formed on the substrate surface using the Beneq TFS200ALD atomic layer deposition equipment using atomic layer deposition technology. The actual product obtained after film formation is shown in the figure below. Figure 5 Specific methods of atomic layer deposition include:
[0060] (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 (4 inches);
[0061] (2) flushing and / or evacuating the processing chamber with inert argon gas multiple times;
[0062] (3) reacting a tungsten-containing precursor with a reducing reactant to form a layer of tungsten metal on the substrate, wherein the reaction occurs on the surface of the substrate and is optionally assisted by an electric current;
[0063] (4) Flushing and / or evacuating the processing chamber with inert argon gas multiple times, repeating the above process to achieve a suitable tungsten electron layer;
[0064] The reaction temperature is controlled at 200°C, the vacuum degree is controlled at -1.0-1.0 MPa, and the entire operation should be carried out in an inert gas atmosphere such as argon.
[0065] The conductivity of the film-formed sample was tested using the instrument CHI660E. The test results are as follows: Figure 6 shown.
[0066] As can be seen from the figure, its impedance R is 325 / ohm. According to the conductivity formula, 5 S / cm, where L is thickness, R is resistance, and A is the cross-sectional area of the material. From the above, it can be seen that the metal tungsten complex has good conductivity after film formation.
[0067] 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. Use of a tungsten-containing complex as a precursor in an ALD or CVD process, characterized in that: The structural formula of the tungsten-containing complex is shown in the following formula (1); （1）； Wherein, X in formula (1) is selected from any one of F, Cl, Br, I, CO, and MeCN; R is selected from any one of the following structures: ； ； R 1 is H; n in R is selected from any one of 0, 1, 2, 3, 4, and 5.
2. The application according to claim 1, characterized in that The structural formula of the tungsten-containing complex is or .
3. The use according to claim 1, characterized in that The molar mass of the tungsten-containing complex is ≤500 g / mol.
4. The use according to claim 1, characterized in that The preparation method of the tungsten-containing complex comprises: (1) dissolving a metallic tungsten raw material in an anhydrous organic solvent, adding an alkaline substance, and reacting at 40-80° C. for 1-2 hours; (2) cooling the reaction solution to room temperature, and then adding a nucleophilic or electrophilic reagent thereto to complete the reaction; (3) filtering, concentrating, and recrystallizing to obtain the complex; the molar ratio of the metallic tungsten raw material, the alkaline substance, and the nucleophilic or electrophilic reagent is 1:1.5-3:1-3.
5. The use according to claim 4, characterized in that In the preparation method, the molar ratio of the metal tungsten raw material, the alkaline substance, and the nucleophilic or electrophilic reagent is 1:2:
1.
6. The use according to claim 4, characterized in that In the preparation method, the alkaline substance is selected from one or more combinations of cesium carbonate, potassium carbonate, sodium carbonate, sodium bicarbonate, potassium bicarbonate, sodium hydride, and sodium-potassium alloy.
7. The use according to claim 4, characterized in that In the preparation method, the nucleophilic reagent is an organic metal nucleophilic reagent; and the electrophilic reagent is an organic halide electrophilic reagent.
8. The use according to claim 1, characterized in that The preparation method of the tungsten-containing complex comprises: (1) dissolving a metallic tungsten raw material in an anhydrous organic solvent, adding a halogenating agent, heating to 40-80° C., and irradiating with white light for a reaction of 2-10 hours; (2) cooling and recrystallizing; (3) washing the precipitated solid and drying the solid; the molar ratio of the metallic tungsten raw material to the halogenating agent is 1:1-3.
9. The use according to claim 8, characterized in that The metal tungsten raw material is selected from cyclopentadienyl tungsten polymer.
10. The use according to claim 8, characterized in that The organic solvent is selected from one or more combinations of tetrahydrofuran, acetonitrile, benzonitrile, 1,2-dichloroethane, toluene, chlorobenzene, N,N-dimethylformamide, N,N-dimethylacetamide, and 1,4-dioxane.