Preparation method of titanium nitride film and titanium nitride film
By exciting the reactive gas into plasma outside the reaction chamber and optimizing the carrier gas and radio frequency power, the problem of substrate damage caused by plasma bombardment was solved, and high-uniformity and high-quality titanium nitride thin film deposition was achieved.
Patent Information
- Application Number
- CN202510883453.1
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-06-29
- Publication Date
- 2025-11-18
AI Technical Summary
In existing technologies, high-energy plasma bombardment of the substrate during plasma-enhanced atomic layer deposition (PEALD) causes substrate lattice distortion, damages the substrate, and affects the uniformity of the thin film.
The reactive gas is excited into plasma outside the reaction chamber, and then plasma is introduced into the reaction chamber to reduce the physical damage to the substrate caused by ion bombardment. The thin film deposition process is optimized by controlling the carrier gas and radio frequency power.
This improved the uniformity and conductivity of the titanium nitride film on the substrate surface, reduced the resistivity and impurity content of the film, and increased the deposition rate and step coverage.
Smart Images
Figure CN120967326A_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of semiconductor technology, and more particularly to a method for preparing titanium nitride thin films and titanium nitride thin films. Background Technology
[0002] PEALD (Plasma Enhanced Atomic Layer Deposition) is an effective method for preparing high-quality ultrathin films at low temperatures. It involves alternately pulsed introduction of a gaseous precursor into a reaction chamber, where it undergoes surface chemisorption on the substrate, thus forming a thin film layer by layer. The chemisorption of the precursor on the surface is self-limiting and self-saturating, allowing the film thickness to be controlled by the number of cycles.
[0003] Currently, throughout the entire deposition cycle, a carrier gas flow (usually inert gases such as He, Ne, and Ar) is required to remove excess precursors and byproducts adsorbed on the reaction surface. The supply method for the material pulses within a unit cycle is generally as follows: first, a precursor pulse is introduced, followed by carrier gas flushing, then a reactant pulse is supplied. This pulse accompanies the plasma flow; under the action of the plasma device, the reactants are transformed into plasma and adsorbed onto the substrate surface, reacting with the precursors. Finally, the carrier gas flushes, completing one deposition cycle.
[0004] However, in the prior art, the high-energy plasma generated in the reaction chamber that supports the substrate bombards the substrate, which can easily cause lattice distortion and damage to the substrate, thereby reducing the uniformity of the target thin film formed on the substrate surface. Summary of the Invention
[0005] The purpose of this invention is to provide a method for preparing titanium nitride thin films and titanium nitride thin films, which can reduce the damage to the substrate surface caused by ion bombardment, thereby improving the uniformity of the target thin film formed on the substrate surface.
[0006] To achieve the above objectives, in a first aspect, the present invention provides a method for preparing a titanium nitride thin film. The method for preparing the titanium nitride thin film includes:
[0007] First, a semiconductor substrate is provided;
[0008] Next, a titanium source precursor is introduced into the reaction chamber where the semiconductor substrate is located, and the titanium source precursor is adsorbed on the semiconductor substrate to form an adsorption layer.
[0009] Next, the first carrier gas is introduced into the reaction chamber to purge and remove excess titanium source precursor;
[0010] Next, the reactant gas is excited into a reactant gas plasma outside the reaction chamber;
[0011] Next, reactive gas plasma is introduced into the reaction chamber;
[0012] Next, the adsorbed layer reacts with the reactive gas plasma to generate a titanium nitride thin film;
[0013] Next, a second carrier gas is introduced into the reaction chamber to purge and remove excess reaction gas plasma;
[0014] Next, according to the set number of cycles, a titanium nitride thin film of the preset thickness is deposited.
[0015] In the method for preparing titanium nitride thin films provided by this invention, the reactant gas is first excited into a reactant gas plasma outside the reaction chamber, and then the reactant gas plasma is introduced into the reaction chamber. Compared with directly exciting the gas to generate plasma inside the reaction chamber (or above the semiconductor substrate), this application excites the reactant gas into a reactant gas plasma outside the reaction chamber, which can reduce the physical damage and thermal load caused by ion bombardment (or plasma bombardment) to the semiconductor substrate, that is, it can reduce the damage caused to the surface of the semiconductor substrate by ion bombardment. Based on this, the uniformity of the titanium nitride thin film formed on the surface of the semiconductor substrate can be improved.
[0016] In one implementation, exciting the reactant gas into a reactant gas plasma outside the reaction chamber includes:
[0017] A third carrier gas and a reactant gas are introduced into a plasma generator located outside the reaction chamber, thereby exciting the third carrier gas and the reactant gas into a third carrier gas plasma and a reactant gas plasma; the reactant gas includes nitrogen, and the third carrier gas includes argon.
[0018] Introducing reactive gas plasma into the reaction chamber includes:
[0019] The third carrier gas plasma and the reactive gas plasma are introduced into the reaction chamber.
[0020] In one implementation, the flow rate ratio of argon to nitrogen is greater than or equal to 1:9 and less than or equal to 3:7;
[0021] And / or, the radio frequency power when the third carrier gas and the reactant gas are excited into a third carrier gas plasma and a reactant gas plasma is greater than or equal to 150W and less than or equal to 200W.
[0022] In one implementation, the reaction temperature during which the adsorbed layer reacts with the reactive gas plasma to generate a titanium nitride thin film is greater than or equal to 250°C and less than or equal to 400°C.
[0023] In one implementation, the first carrier gas purging time is greater than or equal to 5s and less than or equal to 15s.
[0024] In one implementation, a titanium source precursor is introduced into the reaction chamber containing the semiconductor substrate. Before the titanium source precursor adsorbs onto the semiconductor substrate to form an adsorption layer, the method for preparing the titanium nitride thin film further includes:
[0025] Hydrogen gas was excited into hydrogen plasma using glow discharge at 20 Pa.
[0026] Hydrogen plasma is introduced into the reaction chamber;
[0027] The surface of the semiconductor substrate is activated by bombarding it with hydrogen plasma; wherein the bombardment time is greater than or equal to 20 min and less than or equal to 50 min.
[0028] In one implementation, after providing a semiconductor substrate, a titanium source precursor is introduced into a reaction chamber containing the semiconductor substrate. Before the titanium source precursor is adsorbed on the semiconductor substrate to form an adsorption layer, the method for preparing the titanium nitride thin film further includes:
[0029] The semiconductor substrate was ultrasonically cleaned sequentially with acetone, ethanol and deionized water to obtain a cleaned semiconductor substrate.
[0030] The cleaned semiconductor substrate is subjected to vacuum heating treatment to obtain a treated semiconductor substrate;
[0031] The temperature for vacuum heating treatment is 250℃.
[0032] In one implementation, the titanium source precursor includes: TiCl4;
[0033] And / or, when the number of cycles is 1000, a titanium nitride thin film with a preset thickness of 46.93 nm is obtained.
[0034] In one implementation, after depositing a titanium nitride thin film of a preset thickness according to a set number of cycles, the method for preparing the titanium nitride thin film further includes:
[0035] Under the protection of an inert gas atmosphere, the temperature inside the reaction chamber is reduced to less than 80°C, and the obtained titanium nitride film of the preset thickness is removed.
[0036] Secondly, the present invention also provides a titanium nitride thin film. This titanium nitride thin film is prepared using the titanium nitride thin film preparation method described in the above technical solution.
[0037] The beneficial effects of the titanium nitride thin film provided by the present invention are the same as those of the titanium nitride thin film preparation method described in the above technical solution, and will not be repeated here. Attached Figure Description
[0038] The accompanying drawings, which are included to provide a further understanding of the invention and form part of this invention, illustrate exemplary embodiments of the invention and are used to explain the invention, but do not constitute an undue limitation of the invention. In the drawings:
[0039] Figure 1 This is a graph showing the test results of the titanium nitride film thickness uniformity in an embodiment of the present invention;
[0040] Figure 2 This is a scanning electron microscope image of a semiconductor substrate with a titanium nitride thin film formed in an embodiment of the present invention;
[0041] Figure 3 This is a macroscopic image of a titanium nitride thin film grown by PEALD in an embodiment of the present invention;
[0042] Figure 4 This is a graph showing the test results of a thin film thickness ellipsometer in an embodiment of the present invention.
[0043] Figure label:
[0044] 1-Semiconductor substrate, 2-Titanium nitride thin film. Detailed Implementation
[0045] To make the technical problems to be solved, the technical solutions, and the beneficial effects of the present invention clearer, the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. It should be understood that the specific embodiments described herein are only used to explain the present invention and are not intended to limit the present invention.
[0046] It should be noted that when a component is referred to as being "fixed to" or "set on" another component, it can be directly on or indirectly on that other component. When a component is referred to as being "connected to" another component, it can be directly connected to or indirectly connected to that other component.
[0047] Furthermore, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of indicated technical features. Thus, a feature defined as "first" or "second" may explicitly or implicitly include one or more of that feature. In the description of this invention, "a plurality of" means two or more, unless otherwise explicitly specified. "Several" means one or more, unless otherwise explicitly specified.
[0048] In the description of this invention, it should be understood that the terms "upper", "lower", "front", "rear", "left", "right", etc., indicate the orientation or positional relationship based on the orientation or positional relationship shown in the accompanying drawings. They are only for the convenience of describing this invention and simplifying the description, and do not indicate or imply that the device or element referred to must have a specific orientation, or be constructed and operated in a specific orientation. Therefore, they should not be construed as limitations on this invention.
[0049] In the description of this invention, it should be noted that, unless otherwise explicitly specified and limited, the terms "installation," "connection," and "linking" should be interpreted broadly. For example, they can refer to a fixed connection, a detachable connection, or an integral connection; they can refer to a mechanical connection or an electrical connection; they can refer to a direct connection or an indirect connection through an intermediate medium; they can refer to the internal communication of two components or the interaction between two components. Those skilled in the art can understand the specific meaning of the above terms in this invention according to the specific circumstances.
[0050] To address the aforementioned technical problems, in a first aspect, the present invention provides a method for preparing a titanium nitride thin film. The method for preparing the titanium nitride thin film includes:
[0051] Step 101: Provide a semiconductor substrate;
[0052] In some embodiments, the semiconductor substrate can be any one of sapphire (Al2O3), Si, or Si / SiO2 substrate, as long as the material of the semiconductor substrate meets the actual requirements.
[0053] Before actually preparing the titanium nitride thin film, the semiconductor substrate needs to be treated. As one possible approach, step 102 involves sequentially ultrasonically cleaning the semiconductor substrate with acetone, ethanol, and deionized water to obtain a cleaned semiconductor substrate. At this point, grease and oxides on the surface of the semiconductor substrate are removed, resulting in a clean semiconductor substrate with high cleanliness and no surface impurities.
[0054] Step 103: Perform vacuum heating treatment on the cleaned semiconductor substrate to obtain a treated semiconductor substrate; wherein the vacuum heating treatment temperature is 250℃. This removes residual acetone, ethanol, and deionized water, further improving the cleanliness of the treated semiconductor substrate. It should be noted that the above vacuum heating treatment temperature can be adjusted according to actual needs and is not limited to the above data.
[0055] In summary, using a semiconductor substrate treated in steps 102 and 103 to prepare titanium nitride thin films can reduce or eliminate the influence of external factors on the plasma-enhanced atomic layer deposition (PEA) growth process. Furthermore, it can improve the bonding strength between the treated semiconductor substrate and the titanium source precursor, or between the semiconductor substrate and the titanium nitride thin film, thus contributing to increased electrical conductivity of the titanium nitride thin film.
[0056] Step 104: Excite hydrogen gas into hydrogen plasma using glow discharge at 20 Pa;
[0057] Step 105: Introduce hydrogen plasma into the reaction chamber;
[0058] Step 106: Activate the surface of the semiconductor substrate by bombarding it with hydrogen plasma; wherein the bombardment time is greater than or equal to 20 min and less than or equal to 50 min. For example, the bombardment time can be 20 min, 25 min, 30 min, 35 min, 40 min, 45 min, or 50 min, etc.
[0059] By bombarding the surface of a semiconductor substrate with hydrogen plasma, the surface of the semiconductor substrate is activated, which can enhance the bonding strength between the titanium nitride film and the semiconductor substrate, and help to further increase the conductivity of the titanium nitride film.
[0060] Step 107: Introduce a titanium source precursor into the reaction chamber containing the semiconductor substrate. The titanium source precursor is adsorbed onto the semiconductor substrate to form an adsorption layer.
[0061] For example, the titanium source precursor includes TiCl4. It should be noted that the aforementioned TiCl4 is titanium tetrachloride, a carbon-free inorganic compound. In the actual preparation of titanium nitride thin films, TiCl4 vapor stored in a bubble flask is introduced into the reaction chamber in a pulsed manner, and TiCl4 adsorbs onto the semiconductor substrate to form an adsorption layer on the surface of the semiconductor substrate.
[0062] Step 108: Introduce a first carrier gas into the reaction chamber to purge and remove excess titanium source precursor;
[0063] For example, the first carrier gas may be an inert gas such as argon or nitrogen.
[0064] In some embodiments, the first carrier gas purging time is greater than or equal to 5 s and less than or equal to 15 s to completely remove or remove most of the excess titanium source precursor, so as to avoid affecting the subsequent preparation process. For example, the first carrier gas purging time can be 5 s, 6 s, 7 s, 8 s, 9 s, 10 s, 11 s, 12 s, 13 s, 14 s or 15 s, etc.
[0065] Step 109: Excite the reaction gas into a reaction gas plasma outside the reaction chamber;
[0066] Specifically, a third carrier gas and a reactant gas are introduced into a plasma generator located outside the reaction chamber, and the third carrier gas and the reactant gas are excited into a third carrier gas plasma and a reactant gas plasma.
[0067] In some embodiments, the reactant gas includes nitrogen, the third carrier gas includes argon, and the plasma generator can be a remote plasma source.
[0068] In existing technologies, atomic-level layer-by-layer growth (single-cycle growth of 0.1 nm-0.2 nm) is achieved by alternating pulses of precursor gases (such as TiCl4 and NH3) to induce a self-limiting chemical reaction on the surface of a semiconductor substrate. However, in this application, since the reaction gas includes nitrogen, the third carrier gas includes argon, and the titanium source precursor includes TiCl4, it is clear that the material used to prepare the titanium nitride thin film does not contain H ions, thus eliminating the problem of introducing hydrogen doping. Furthermore, plasma radicals (such as N2)... + Directly breaking precursor chemical bonds (such as Ti-Cl bonds) reduces byproducts and improves reaction efficiency.
[0069] As one possible implementation, the flow ratio of argon to nitrogen is greater than or equal to 1:9 and less than or equal to 3:7. For example, the flow ratio of argon to nitrogen can be 1:9, 8:63, 1:7, 10:63, 11:63, 12:63, 13:63, 14:63, 15:63, 16:63, 17:63, 2:7, 19:63, 20:63, 1:3, 22:63, 23:63, 24:63, 25:63, 26:63, or 3:7, etc.
[0070] When the flow ratio of argon to nitrogen is within the specified range, excessively high or low nitrogen concentrations can be avoided. Specifically, excessively high nitrogen concentration results in excessively low argon concentration. Insufficient argon concentration affects ionization, thus hindering nitrogen excitation into nitrogen plasma and impacting the subsequent reaction between the nitrogen plasma and the adsorption layer. Furthermore, excessively low argon concentration leads to instability in the titanium nitride thin film preparation process, affecting the resistivity, step coverage, and uniformity of the film. Conversely, excessively low nitrogen concentration and excessively high argon concentration also negatively impact the resistivity, step coverage, and uniformity of the titanium nitride thin film. Therefore, controlling the argon to nitrogen flow ratio within the specified range balances the resistivity, step coverage, and uniformity of the titanium nitride thin film, thereby improving its quality.
[0071] This application describes a method to excite a third carrier gas and a reactant gas into a highly reactive plasma using radio frequency (RF) or microwave, replacing the thermochemical reaction. As one possible implementation, the RF power used to excite the third carrier gas and reactant gas into a third carrier gas plasma and a reactant gas plasma is greater than or equal to 150W and less than or equal to 200W. For example, the RF power can be 150W, 160W, 170W, 180W, 190W, or 200W, etc.
[0072] Step 1010: Introduce the reaction gas plasma into the reaction chamber;
[0073] Based on the previous description, the third carrier gas plasma and the reactant gas plasma are introduced into the reaction chamber in the form of pulses.
[0074] Step 1011: The adsorbed layer reacts with the reactive gas plasma to generate a titanium nitride thin film;
[0075] In some embodiments, the reaction temperature during the reaction of the adsorbed layer with the reactive gas plasma to form a titanium nitride thin film is greater than or equal to 250°C and less than or equal to 400°C. For example, the reaction temperature may be 250°C, 300°C, 310°C, 330°C, 350°C, 380°C, or 400°C, etc.
[0076] Compared to the preparation of titanium nitride thin films using thermal ALD (Thermal Atomic Layer Deposition), the preparation method provided in this application lowers the reaction temperature, i.e., this application employs low-temperature deposition. Specifically, thermal ALD involves high reaction temperatures; metal nitrides (such as TiN) require activation temperatures above 400°C (e.g., TiCl4 + 2NH3 → TiN + 4HCl + H2), making it incompatible with low-temperature processes, such as BEOL (Back-end of Line) interconnect layers. In this application, plasma provides the activation energy, eliminating the need for high-temperature thermal decomposition. This application is compatible with low-temperature processes, such as BEOL back-end interconnect layers.
[0077] Step 1012: Introduce a second carrier gas into the reaction chamber to purge and remove excess reaction gas plasma;
[0078] For example, the second carrier gas can be an inert gas such as argon or nitrogen, and the purging time of the second carrier gas can be set according to the actual situation.
[0079] Purging with the second carrier gas can completely or mostly remove excess reactive gas plasma and other reaction byproducts, avoiding interference with subsequent preparation processes. It should be noted that the second carrier gas, along with the aforementioned first carrier gas, can also purge and remove other unwanted substances to ensure the successful preparation of titanium nitride films.
[0080] Step 1013: Deposit a titanium nitride thin film of the preset thickness according to the set number of cycles.
[0081] Steps 107 to 1012 above are single-cycle processes. The number of cycles is set according to actual needs to obtain a titanium nitride thin film with a preset thickness.
[0082] For example, when the number of cycles is 1000, a titanium nitride thin film with a preset thickness of 46.93 nm can be obtained.
[0083] Step 1014: Under the protection of an inert gas atmosphere, reduce the temperature inside the reaction chamber to less than 80°C and remove the titanium nitride film with the preset film thickness.
[0084] For example, heating of the reaction chamber is stopped, allowing the temperature inside the chamber to drop to below 80°C. The specific temperature after this reduction can be set according to actual conditions and is not specifically limited here. Furthermore, the inert gas can be nitrogen or helium, etc. Using the above technical solution can prevent oxidation of the obtained titanium nitride film, thus ensuring the quality of the titanium nitride film.
[0085] In the method for preparing titanium nitride thin films provided in this invention, the reactant gas is first excited into a reactant gas plasma outside the reaction chamber, and then the reactant gas plasma is introduced into the reaction chamber. Compared with directly exciting the gas to generate plasma inside the reaction chamber (or above the semiconductor substrate) supporting the semiconductor substrate, this application excites the reactant gas into a reactant gas plasma outside the reaction chamber, which can reduce the physical damage and thermal load caused by ion bombardment (or plasma bombardment) to the semiconductor substrate, that is, it can reduce the damage caused to the surface of the semiconductor substrate by ion bombardment. Based on this, the uniformity of the titanium nitride thin film formed on the surface of the semiconductor substrate can be improved. Specifically, see Figure 1 , Figure 1 This is a graph showing the test results of the titanium nitride thin film thickness uniformity in an embodiment of the present invention, combined with... Figure 1 It is known that in this application, when the reaction temperature is 250°C, the uniformity of the titanium nitride thin film formed on a 12-inch semiconductor substrate is 0.79%, which is good.
[0086] The titanium nitride thin film obtained using the preparation method provided in this application achieves a resistivity of less than or equal to 80 μΩ·cm at a reaction temperature of 250°C to 400°C. In some embodiments, the resistivity of the titanium nitride thin film is less than 80 μΩ·cm at a reaction temperature of 250°C. In other embodiments, referring to Table 1, which is a schematic table of sheet resistance test results using four probes in the embodiments of the present invention, it can be seen from Table 1 that the sheet resistance of the titanium nitride thin film is 159.8 Ω, and the converted resistivity of the titanium nitride thin film is approximately 75 μΩ·cm.
[0087] Table 1. Schematic diagram of sheet resistance test results using four probes in the embodiments of the present invention.
[0088]
[0089] The titanium nitride thin film obtained using the preparation method provided in this application has a step coverage greater than 99%. In some embodiments, when the trench aspect ratio is 3:1, the step coverage of the titanium nitride thin film is greater than 99%. When the trench depth is 0.15 μm, the step coverage of the titanium nitride thin film is greater than 99%. See, for example, [link to relevant documentation]. Figure 2 , Figure 2 This is a scanning electron microscope (SEM) image of a semiconductor substrate with a titanium nitride thin film formed in an embodiment of the present invention. From... Figure 2 As can be seen from the scanning electron microscope image, there is a clear boundary between the titanium nitride thin film 2 and the semiconductor substrate 1, and the step coverage of the titanium nitride thin film 2 is greater than 99%.
[0090] Furthermore, in existing thermal ALD processes, TiCl4 + 2NH3 → TiN + 4HCl + H2 is used, or titanium tetrachloride, a carbon-containing inorganic compound, is used as a precursor to prepare titanium nitride films. However, incomplete thermal reactions in existing technologies result in residual Cl- and C- impurities, reducing conductivity and causing high resistivity (>200 μΩ·cm). Existing CVD (Chemical Vapor Deposition) methods for preparing TiN films suffer from poor step coverage and high impurity content (chlorine residue >5 at%). However, in conjunction with the foregoing description, the plasma free radical (e.g., N) method in this application... + The precursor chemical bonds (e.g., Ti-Cl bonds) are directly broken, and the titanium source precursor (carbon-free inorganic titanium tetrachloride) adsorbs onto the semiconductor substrate to form an adsorption layer. After the titanium source precursor forms an adsorption layer on the semiconductor substrate, a first carrier gas is introduced into the reaction chamber to purge and remove excess titanium source precursor. This reduces or eliminates residual Cl- and C- impurities, improving conductivity. Furthermore, the performance of the titanium nitride thin film is optimized, exhibiting higher density and lower impurities (oxygen content <5 at.%).
[0091] Furthermore, existing thermal ALD deposition rates are slow, requiring multiple cycles to compensate for insufficient reaction efficiency; the ALD deposition rate in existing technologies is also slow. However, in this application, the deposition rate of the titanium nitride film in a single cycle is... Compared to existing atomic layer deposition methods, the deposition rate of titanium nitride thin films is increased by 40%, and the deposition rate is also improved compared to thermal ALD.
[0092] See Figure 3 and Figure 4 , Figure 3 This is a macroscopic image of a titanium nitride thin film grown by PEALD in an embodiment of the present invention; Figure 4 This is a graph showing the test results of a thin film thickness ellipsometer in an embodiment of the present invention. Figure 4 The test results can be used to calculate the growth rate of PEALD-grown titanium nitride films based on the thickness. Combined with... Figure 3 and Figure 4 It can be seen that for a 12-inch semiconductor substrate, the deposition rate of titanium nitride thin film is increased by 40% while maintaining a step coverage of >99%.
[0093] In addition, in actual manufacturing, it can reduce gate resistance by 37% and increase device yield by 5.2 percentage points.
[0094] In summary, the preparation method provided in this application can yield high-purity titanium nitride thin films with low resistivity.
[0095] The preparation process of titanium nitride thin films is described below using three different examples. It should be understood that the following description is for illustrative purposes only and is not intended to limit the specific application.
[0096] Example 1:
[0097] Step 101: Provide a semiconductor substrate;
[0098] Step 102: The semiconductor substrate is ultrasonically cleaned sequentially with acetone, ethanol and deionized water to obtain the cleaned semiconductor substrate;
[0099] Step 103: Perform vacuum heating treatment on the cleaned semiconductor substrate to obtain the treated semiconductor substrate; wherein, the temperature of vacuum heating treatment is 250℃.
[0100] Step 104: Excite hydrogen gas into hydrogen plasma using glow discharge at 20 Pa;
[0101] Step 105: Introduce hydrogen plasma into the reaction chamber;
[0102] Step 106: Activate the surface of the semiconductor substrate by bombarding it with hydrogen plasma; wherein the bombardment time is 20 min.
[0103] Step 107: TiCl4 is introduced into the reaction chamber where the semiconductor substrate is located, and TiCl4 is adsorbed on the semiconductor substrate to form an adsorption layer;
[0104] Step 108: Introduce argon gas into the reaction chamber to purge and remove excess TiCl4;
[0105] Step 109: Argon and nitrogen are introduced into the plasma generator located outside the reaction chamber, and the argon and nitrogen are excited into argon plasma and nitrogen plasma outside the reaction chamber. The flow ratio of argon to nitrogen is 1:9; the radio frequency power when argon and nitrogen are converted into argon plasma and nitrogen plasma is 150W.
[0106] Step 1010: Introduce argon plasma and nitrogen plasma into the reaction chamber in a pulsed manner;
[0107] Step 1011: The TiCl4 adsorption layer reacts with nitrogen plasma to form a titanium nitride film; the reaction temperature when the TiCl4 adsorption layer reacts with nitrogen plasma to form a titanium nitride film is 250℃, thus completing one cycle.
[0108] Step 1012: Purge the reaction chamber with helium gas to remove excess nitrogen plasma and reaction byproducts;
[0109] Step 1013: Deposit a titanium nitride thin film of the preset thickness according to the set number of cycles.
[0110] Step 1014: Under the protection of an inert gas atmosphere, reduce the temperature inside the reaction chamber to 79°C and remove the titanium nitride film with the preset thickness.
[0111] Example 2:
[0112] Step 101: Provide a semiconductor substrate;
[0113] Step 102: The semiconductor substrate is ultrasonically cleaned sequentially with acetone, ethanol and deionized water to obtain the cleaned semiconductor substrate;
[0114] Step 103: Perform vacuum heating treatment on the cleaned semiconductor substrate to obtain the treated semiconductor substrate; wherein, the temperature of vacuum heating treatment is 250℃.
[0115] Step 104: Excite hydrogen gas into hydrogen plasma using glow discharge at 20 Pa;
[0116] Step 105: Introduce hydrogen plasma into the reaction chamber;
[0117] Step 106: Activate the surface of the semiconductor substrate by bombarding it with hydrogen plasma; wherein the bombardment time is 25 min.
[0118] Step 107: TiCl4 is introduced into the reaction chamber where the semiconductor substrate is located, and TiCl4 is adsorbed on the semiconductor substrate to form an adsorption layer;
[0119] Step 108: Introduce argon gas into the reaction chamber to purge and remove excess TiCl4;
[0120] Step 109: Argon and nitrogen are introduced into the plasma generator located outside the reaction chamber, and the argon and nitrogen are excited into argon plasma and nitrogen plasma outside the reaction chamber. The flow ratio of argon to nitrogen is 2:7; the radio frequency power when argon and nitrogen are converted into argon plasma and nitrogen plasma is 180W.
[0121] Step 1010: Introduce argon plasma and nitrogen plasma into the reaction chamber in a pulsed manner;
[0122] Step 1011: The TiCl4 adsorption layer reacts with nitrogen plasma to form a titanium nitride film; the reaction temperature when the TiCl4 adsorption layer reacts with nitrogen plasma to form a titanium nitride film is 300℃, thus completing one cycle.
[0123] Step 1012: Purge the reaction chamber with helium gas to remove excess nitrogen plasma and reaction byproducts;
[0124] Step 1013: Deposit a titanium nitride thin film of the preset thickness according to the set number of cycles.
[0125] Step 1014: Under the protection of an inert gas atmosphere, reduce the temperature inside the reaction chamber to 72°C and remove the titanium nitride film with the preset thickness.
[0126] Example 3:
[0127] Step 101: Provide a semiconductor substrate;
[0128] Step 102: The semiconductor substrate is ultrasonically cleaned sequentially with acetone, ethanol and deionized water to obtain the cleaned semiconductor substrate;
[0129] Step 103: Perform vacuum heating treatment on the cleaned semiconductor substrate to obtain the treated semiconductor substrate; wherein, the temperature of vacuum heating treatment is 250℃.
[0130] Step 104: Excite hydrogen gas into hydrogen plasma using glow discharge at 20 Pa;
[0131] Step 105: Introduce hydrogen plasma into the reaction chamber;
[0132] Step 106: Activate the surface of the semiconductor substrate by bombarding it with hydrogen plasma; wherein the bombardment time is 30 min.
[0133] Step 107: TiCl4 is introduced into the reaction chamber where the semiconductor substrate is located, and TiCl4 is adsorbed on the semiconductor substrate to form an adsorption layer;
[0134] Step 108: Introduce argon gas into the reaction chamber to purge and remove excess TiCl4;
[0135] Step 109: Argon and nitrogen are introduced into the plasma generator located outside the reaction chamber, and the argon and nitrogen are excited into argon plasma and nitrogen plasma outside the reaction chamber. The flow ratio of argon to nitrogen is 3:7; the radio frequency power when argon and nitrogen are converted into argon plasma and nitrogen plasma is 200W.
[0136] Step 1010: Introduce argon plasma and nitrogen plasma into the reaction chamber in a pulsed manner;
[0137] Step 1011: The TiCl4 adsorption layer reacts with nitrogen plasma to form a titanium nitride film; the reaction temperature when the TiCl4 adsorption layer reacts with nitrogen plasma to form a titanium nitride film is 400℃, thus completing one cycle.
[0138] Step 1012: Purge the reaction chamber with helium gas to remove excess nitrogen plasma and reaction byproducts;
[0139] Step 1013: Deposit a titanium nitride thin film of the preset thickness according to the set number of cycles.
[0140] Step 1014: Under the protection of an inert gas atmosphere, reduce the temperature inside the reaction chamber to 70°C and remove the titanium nitride film with the preset thickness.
[0141] Secondly, embodiments of the present invention also provide a titanium nitride thin film. This titanium nitride thin film is prepared using the titanium nitride thin film preparation method described in the above technical solution.
[0142] The beneficial effects of the titanium nitride thin film provided in this embodiment of the invention are the same as those of the titanium nitride thin film preparation method described in the above technical solution, and will not be repeated here.
[0143] In the description of the above embodiments, specific features, structures, materials, or characteristics may be combined in any suitable manner in one or more embodiments or examples.
[0144] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any variations or substitutions that can be easily conceived by those skilled in the art within the technical scope disclosed in the present invention should be included within the scope of protection of the present invention. Therefore, the scope of protection of the present invention should be determined by the scope of the claims.
Claims
1. A method for preparing a titanium nitride thin film, characterized in that, include: Provide a semiconductor substrate; A titanium source precursor is introduced into the reaction chamber where the semiconductor substrate is located, and the titanium source precursor is adsorbed on the semiconductor substrate to form an adsorption layer; A first carrier gas is introduced into the reaction chamber to purge and remove excess titanium source precursor; The reactant gas is excited into a reactant gas plasma outside the reaction chamber; The reaction gas plasma is introduced into the reaction chamber; The adsorption layer reacts with the reactive gas plasma to generate a titanium nitride thin film. A second carrier gas is introduced into the reaction chamber to purge and remove excess reaction gas plasma; Based on the set number of cycles, a titanium nitride thin film of the preset thickness is deposited.
2. The method for preparing titanium nitride thin film according to claim 1, characterized in that, Exciting the reactant gas into a reactant gas plasma outside the reaction chamber includes: A third carrier gas and a reactive gas are introduced into a plasma generator located outside the reaction chamber, thereby exciting the third carrier gas and the reactive gas into a third carrier gas plasma and a reactive gas plasma; the reactive gas includes nitrogen, and the third carrier gas includes argon. Introducing reactive gas plasma into the reaction chamber includes: The third carrier gas plasma and the reactant gas plasma are introduced into the reaction chamber.
3. The method for preparing titanium nitride thin film according to claim 2, characterized in that, The flow rate ratio of the argon gas to the nitrogen gas is greater than or equal to 1:9 and less than or equal to 3:7; And / or, the radio frequency power when the third carrier gas and the reactant gas are excited into a third carrier gas plasma and a reactant gas plasma is greater than or equal to 150W and less than or equal to 200W.
4. The method for preparing titanium nitride thin film according to claim 1, characterized in that, The reaction temperature at which the adsorbed layer reacts with the reactive gas plasma to form a titanium nitride thin film is greater than or equal to 250°C and less than or equal to 400°C.
5. The method for preparing titanium nitride thin film according to claim 1, characterized in that, The first carrier gas purging time is greater than or equal to 5s and less than or equal to 15s.
6. The method for preparing titanium nitride thin film according to claim 1, characterized in that, The method for preparing the titanium nitride thin film further includes introducing a titanium source precursor into the reaction chamber containing the semiconductor substrate, and before the titanium source precursor adsorbs onto the semiconductor substrate to form an adsorption layer: Hydrogen gas was excited into hydrogen plasma using glow discharge at 20 Pa. Hydrogen plasma is introduced into the reaction chamber; The surface of the semiconductor substrate is activated by bombarding it with hydrogen plasma; wherein the bombardment time is greater than or equal to 20 min and less than or equal to 50 min.
7. The method for preparing titanium nitride thin film according to claim 5, characterized in that, After providing a semiconductor substrate, a titanium source precursor is introduced into the reaction chamber where the semiconductor substrate is located. Before the titanium source precursor is adsorbed on the semiconductor substrate to form an adsorption layer, the method for preparing the titanium nitride thin film further includes: The semiconductor substrate was ultrasonically cleaned sequentially with acetone, ethanol and deionized water to obtain a cleaned semiconductor substrate. The cleaned semiconductor substrate is subjected to vacuum heating treatment to obtain a treated semiconductor substrate; The temperature for vacuum heating treatment is 250℃.
8. The method for preparing titanium nitride thin film according to claim 1, characterized in that, The titanium source precursor includes: TiCl4; And / or, when the number of cycles is 1000, a titanium nitride thin film with a preset thickness of 46.93 nm is obtained.
9. The method for preparing titanium nitride thin film according to claim 1, characterized in that, After depositing a titanium nitride thin film of a preset thickness according to a set number of cycles, the method for preparing the titanium nitride thin film further includes: Under the protection of an inert gas atmosphere, the temperature inside the reaction chamber is reduced to less than 80°C, and the obtained titanium nitride film of the preset thickness is removed.
10. A titanium nitride thin film, characterized in that, The titanium nitride thin film is prepared by the preparation method of titanium nitride thin film according to any one of claims 1 to 9.