Method for manufacturing a tantalum nitride film and semiconductor device
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- HC SEMITEK ZHEJIANG CO LTD
- Filing Date
- 2024-12-30
- Publication Date
- 2026-06-05
Smart Images
Figure CN119979169B_ABST
Abstract
Description
Technical Field
[0001] This disclosure belongs to the field of semiconductor technology, and specifically relates to a method for preparing tantalum nitride thin films and semiconductor devices. Background Technology
[0002] A semiconductor device is an electronic device that utilizes the special electrical properties of semiconductor materials to perform a specific function.
[0003] In related technologies, tantalum nitride is widely used in thin-film resistors and other fields due to its various excellent physical and chemical properties. Dry etching or wet etching processes are commonly used to prepare tantalum nitride thin films. However, applying dry etching to tantalum nitride often faces the challenge of low selectivity and difficulty in etching; therefore, wet etching has become a more commonly used method for processing tantalum nitride.
[0004] However, in wet etching processes, the etching rate is difficult to control and the etching uniformity is poor, which makes it impossible to meet the process requirements. Summary of the Invention
[0005] This disclosure provides a method for preparing a tantalum nitride thin film and a semiconductor device, which can effectively control the corrosion rate of the tantalum nitride thin film and improve its corrosion uniformity. The technical solution is as follows:
[0006] In a first aspect, embodiments of this disclosure provide a method for preparing a tantalum nitride thin film, the method comprising:
[0007] A primary corrosion solution is provided, the primary corrosion solution being used to dissolve oxides;
[0008] The tantalum nitride sample was immersed in the primary corrosion solution;
[0009] A secondary corrosion solution is provided, which is a mixed solution of ammonia, hydrogen peroxide and pure water;
[0010] The tantalum nitride sample was immersed in the secondary etching solution to obtain a tantalum nitride film.
[0011] In one implementation of this disclosure, immersing the tantalum nitride sample in the primary etching solution includes:
[0012] The tantalum nitride sample was immersed in the primary corrosion solution for 3-5 minutes.
[0013] In one implementation of this disclosure, immersing the tantalum nitride sample in the primary etching solution further includes:
[0014] During the immersion of the tantalum nitride sample, the primary etching solution is stirred.
[0015] In another implementation of this disclosure, after immersing the tantalum nitride sample in the primary etching solution, the following steps are included:
[0016] The tantalum nitride sample was removed from the primary etching solution;
[0017] The tantalum nitride sample was rinsed with deionized water.
[0018] In another implementation of this disclosure, a secondary etching solution is provided, comprising:
[0019] The secondary corrosion solution is obtained by mixing the ammonia water, the hydrogen peroxide and the pure water in a ratio of 1:4:20.
[0020] In another implementation of this disclosure, before immersing the tantalum nitride sample in the secondary etching solution, the following steps are taken:
[0021] Adjust the temperature of the secondary corrosion solution to 60-70 degrees Celsius.
[0022] In another implementation of this disclosure, immersing the tantalum nitride sample in the secondary etching solution includes:
[0023] The tantalum nitride sample was immersed in the secondary corrosion solution for 10-15 minutes.
[0024] In another implementation of this disclosure, after immersing the tantalum nitride sample in the secondary etching solution, the process includes:
[0025] The tantalum nitride sample was removed from the secondary etching solution;
[0026] The tantalum nitride sample was rinsed with deionized water.
[0027] In another implementation of this disclosure, after rinsing the tantalum nitride sample with deionized water, the following steps are included:
[0028] The tantalum nitride sample was dried to obtain a tantalum nitride film.
[0029] In a second aspect, embodiments of this disclosure provide a semiconductor device including a tantalum nitride thin film, the tantalum nitride thin film being obtained by the preparation method described in the first aspect.
[0030] The beneficial effects of the technical solutions provided in this disclosure are:
[0031] The preparation method provided in this disclosure allows for the etching of tantalum nitride materials to obtain the desired tantalum nitride film. In the preparation process, a primary etching solution is first provided, and the tantalum nitride sample is immersed in the primary etching solution. Since the primary etching solution can dissolve oxides, immersing the tantalum nitride sample in the primary etching solution removes oxides from the surface of the tantalum nitride sample, thus preparing it for subsequent etching processes. Then, a secondary etching solution is provided, and the tantalum nitride sample is immersed in the secondary etching solution. Since the secondary etching solution is a mixture of ammonia, hydrogen peroxide, and pure water, it can etch the tantalum nitride sample immersed in the secondary etching solution. Furthermore, thanks to the properties of ammonia and hydrogen peroxide, the secondary etching solution can achieve uniform etching of the tantalum oxide sample.
[0032] In addition, since the oxides on the surface of the tantalum nitride sample have been removed by the first etching solution, the corrosion rate of the tantalum nitride sample will not be affected by the oxides during the subsequent etching process with the second etching solution, which is beneficial for precise control of the corrosion rate of the tantalum nitride sample.
[0033] In other words, the preparation method provided in this disclosure can effectively control the corrosion rate of tantalum nitride films and improve their corrosion uniformity, thereby meeting process requirements. Attached Figure Description
[0034] To more clearly illustrate the technical solutions in the embodiments of this disclosure, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the accompanying drawings described below are only some embodiments of this disclosure. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.
[0035] Figure 1 This is a flowchart illustrating a method for preparing a tantalum nitride thin film according to an embodiment of this disclosure;
[0036] Figure 2 This is a flowchart of another method for preparing tantalum nitride thin films provided in this disclosure.
[0037] The accompanying drawings have illustrated specific embodiments of this disclosure, which will be described in more detail below. These drawings and descriptions are not intended to limit the scope of the concept in any way, but rather to illustrate the concepts of this disclosure to those skilled in the art through reference to particular embodiments. Detailed Implementation
[0038] To make the objectives, technical solutions, and advantages of this disclosure clearer, the embodiments of this disclosure will be described in further detail below with reference to the accompanying drawings.
[0039] This disclosure provides a method for preparing a tantalum nitride thin film. Figure 1 For a flowchart of the preparation method, see [link to flowchart]. Figure 1 In this embodiment, the preparation method includes:
[0040] Step 101: Provide a primary corrosion solution.
[0041] The primary corrosion solution is used to dissolve oxides.
[0042] Step 102: Immerse the tantalum nitride sample in a primary etching solution.
[0043] Step 103: Provide a secondary corrosion solution.
[0044] The secondary corrosion solution is a mixture of ammonia, hydrogen peroxide, and pure water.
[0045] Step 104: Immerse the tantalum nitride sample in a secondary etching solution to etch a tantalum nitride film.
[0046] The preparation method provided in this disclosure allows for the etching of tantalum nitride materials to obtain the desired tantalum nitride film. In the preparation process, a primary etching solution is first provided, and the tantalum nitride sample is immersed in the primary etching solution. Since the primary etching solution can dissolve oxides, immersing the tantalum nitride sample in the primary etching solution removes oxides from the surface of the tantalum nitride sample, thus preparing the foundation for subsequent etching processes. Then, a secondary etching solution is provided, and the tantalum nitride sample is immersed in the secondary etching solution. Since the secondary etching solution is a mixture of ammonia, hydrogen peroxide, and pure water, it can etch the tantalum nitride sample immersed in the secondary etching solution. Furthermore, thanks to the properties of ammonia and hydrogen peroxide, the secondary etching solution achieves uniform etching of the tantalum oxide sample. In addition, since the oxides on the surface of the tantalum nitride sample have already been removed by the primary etching solution, the etching rate of the tantalum nitride sample during the subsequent etching process with the secondary etching solution is not affected by the oxides, which is beneficial for precisely controlling the etching rate of the tantalum nitride sample.
[0047] In other words, the preparation method provided in this disclosure can effectively control the corrosion rate of tantalum nitride films and improve their corrosion uniformity, thereby meeting process requirements.
[0048] Figure 2 For a flowchart of another method for preparing a tantalum nitride thin film provided in this disclosure embodiment, please refer to [link to flowchart]. Figure 2 In this embodiment, the preparation method includes:
[0049] Step 201: Provide a primary corrosion solution.
[0050] The primary corrosion solution is used to dissolve oxides.
[0051] For example, the primary corrosion solution is a strong acid solution, such as hydrochloric acid solution. In this way, the oxide can be effectively dissolved by the primary corrosion solution.
[0052] It is worth noting that the oxide on the surface of tantalum oxide samples is generally tantalum pentoxide. Hydrochloric acid solution can react chemically with tantalum pentoxide, thereby dissolving it. The chemical formula is as follows:
[0053] Ta₂O₅ + 10HCl = 2TaCl₅ + 5H₂O.
[0054] Step 202: Immerse the tantalum nitride sample in a primary etching solution.
[0055] In the above implementation, the tantalum nitride sample is placed in the container containing the primary etching solution, ensuring that the sample is completely immersed in the solution. Since the primary etching solution can dissolve oxides, it effectively removes any oxides that may be present on the surface of the tantalum nitride sample. Furthermore, the primary etching solution does not have a significant impact on the tantalum nitride sample.
[0056] In addition, since the oxides on the surface of the tantalum nitride sample have been removed by the primary etching solution, the corrosion rate of the tantalum nitride sample will not be affected by the oxides during the subsequent etching process with the secondary etching solution, which is beneficial for precise control of the corrosion rate of the tantalum nitride sample.
[0057] For example, a tantalum nitride sample is immersed in a primary etching solution for 3 to 5 minutes.
[0058] In the above implementation method, the immersion time of the tantalum nitride sample is controlled at 3 to 5 minutes. On the one hand, this ensures that the oxide on the surface of the tantalum nitride sample is fully dissolved by the primary corrosion solution, and on the other hand, it avoids that the primary corrosion solution has too much impact on the tantalum oxide sample itself.
[0059] In this embodiment, the tantalum nitride sample is immersed in a primary etching solution for 3 minutes. Of course, in other embodiments, other durations within the above range may be used, such as 5 minutes, and this disclosure does not limit this.
[0060] In this embodiment, the etching solution is stirred once during the immersion of the tantalum nitride sample.
[0061] This ensures a full reaction between the primary etching solution and the oxide, allowing the primary etching solution to uniformly dissolve the oxide on the surface of the tantalum nitride sample.
[0062] It is worth noting that the stirring time can be selected according to the actual situation, and this disclosure does not impose any restrictions on it.
[0063] Step 203: Remove the tantalum nitride sample from the primary etching solution and rinse it with deionized water.
[0064] In the above implementation, the tantalum nitride sample is rinsed with deionized water to remove the primary corrosion solution remaining on the surface of the tantalum nitride sample.
[0065] Step 204: Provide a secondary corrosion solution.
[0066] The secondary corrosion solution is a mixture of ammonia, hydrogen peroxide, and pure water.
[0067] In the above implementation method, the properties of ammonia and hydrogen peroxide can be used to effectively corrode tantalum nitride samples.
[0068] The corrosion mechanism of tantalum nitride by secondary corrosion solution will be explained below.
[0069] Ammonia is a weak base. In aqueous solution, it partially ionizes into ammonium and hydroxide ions. During the corrosion of tantalum nitride, hydroxide ions can react with the tantalum nitride surface. For example, it may form tantalum hydroxide complexes with the tantalum element in tantalum nitride, thereby damaging the surface structure of tantalum nitride.
[0070] Hydrogen peroxide is a strong oxidizing agent. In solution, it decomposes to produce highly reactive oxygen species, such as hydroxyl radicals. Hydroxyl radicals are highly reactive and can attack the chemical bonds on the surface of tantalum nitride. They can react with the nitrogen-tantalum bonds in tantalum nitride, causing the nitrogen to be released as a nitrogen-containing compound, oxidizing the tantalum, and thus accelerating the corrosion process of tantalum nitride.
[0071] In this embodiment, ammonia, hydrogen peroxide, and pure water are mixed in a ratio of 1:4:20 to obtain a secondary corrosion solution.
[0072] In the process of preparing the secondary corrosion solution, first measure an appropriate amount of ammonia water and pour it into the reaction vessel, then add the corresponding volume of hydrogen peroxide, and finally add the specified volume of water, stir well, and make the solution fully mixed.
[0073] In the above implementation method, mixing ammonia, hydrogen peroxide, and pure water in a ratio of 1:4:20 has the following beneficial effects:
[0074] (1) Excellent corrosion effect: Hydrogen peroxide has strong oxidizing properties and can react with tantalum nitride to break the chemical bonds on the surface of tantalum nitride, thereby achieving corrosion. Ammonia is weakly alkaline and can promote the decomposition of hydrogen peroxide, producing more active substances such as hydroxyl radicals with strong oxidizing properties, which accelerates the corrosion process. The two work together to effectively corrode tantalum nitride, forming a specific microstructure on its surface or achieving the required roughness to meet different application needs.
[0075] (2) High corrosion uniformity: Under the above ratio of ammonia, hydrogen peroxide and pure water, the components of the solution are relatively uniformly distributed, which can make the corrosion reaction proceed uniformly on the surface of tantalum nitride, avoid excessive or insufficient local corrosion, ensure the consistency of the surface quality and performance of tantalum nitride, and facilitate the subsequent precise processing and use of tantalum nitride materials.
[0076] (3) Corrosion rate is easy to control: By adjusting the reaction temperature, time and other conditions, the corrosion rate can be controlled relatively precisely within a certain range. For example, increasing the temperature will speed up molecular motion and increase the reaction rate; decreasing the temperature will slow down the reaction rate. This allows for flexible adjustment according to specific needs to obtain the ideal corrosion effect.
[0077] (4) Relatively safe operation: The secondary corrosion solution prepared in the above proportion is relatively mild in corrosiveness. Compared with some strong corrosive agents, it poses less harm to operators and equipment. It can be operated under normal experimental conditions without the need for special protective equipment or harsh operating environment, which reduces experimental costs and operational difficulty.
[0078] (5) Good environmental friendliness: The secondary corrosion solution with the above ratio is relatively environmentally friendly. Its components are easier to decompose or treat in the natural environment and will not produce harmful substances that are difficult to degrade. It has less pollution to the environment, which is in line with the development concept of green chemistry and reduces the negative impact on the environment.
[0079] Step 205: Adjust the temperature of the secondary corrosion solution to 60~70 degrees Celsius.
[0080] For example, the secondary corrosion solution is added into a heating container, and the heating container heats the secondary corrosion solution to a temperature of 60-70 degrees Celsius.
[0081] Within the aforementioned temperature range, the secondary etching solution can fully etch the tantalum nitride sample to ensure high etching efficiency.
[0082] Increasing the temperature to 60-70 degrees Celsius can accelerate the rate of chemical reactions. According to the Arrhenius equation, the reaction rate constant k increases with increasing temperature. For the reactions of ammonia and tantalum nitride, and hydrogen peroxide and tantalum nitride, the rate at which ammonia ionizes into hydroxide ions and the rate at which hydrogen peroxide decomposes to produce hydroxyl radicals increase with increasing temperature. Furthermore, the increased temperature accelerates the diffusion rate of these reactive substances (hydroxyl ions, hydroxyl radicals, etc.) in the solution, allowing them to come into contact with and react more frequently with the surface of the tantalum nitride sample, thereby increasing the corrosive effect on the tantalum nitride sample.
[0083] In this embodiment, the temperature of the secondary etching solution is adjusted to 65 degrees Celsius. Of course, in other embodiments, the temperature of the secondary etching solution can also be adjusted to other temperatures within the above-mentioned temperature range, and this disclosure does not limit this.
[0084] For example, the heating vessel is a high-temperature and corrosion-resistant reaction vessel, such as a stainless steel reactor lined with polytetrafluoroethylene, to withstand temperatures of 60-70 degrees Celsius and the corrosiveness of the solution.
[0085] Step 206: Immerse the tantalum nitride sample in the secondary etching solution.
[0086] In the above implementation, the tantalum nitride sample is placed in the container containing the secondary etching solution, ensuring that the tantalum nitride sample is completely immersed in the secondary etching solution. Since the secondary etching solution is a mixture of ammonia, hydrogen peroxide, and pure water, it can uniformly and efficiently etch the tantalum nitride sample.
[0087] For example, a tantalum nitride sample is immersed in a secondary etching solution for 10 to 15 minutes.
[0088] In the above implementation method, the immersion time of the tantalum nitride sample is controlled at 10 to 15 minutes. On the one hand, this ensures that the secondary corrosion solution can fully corrode the tantalum nitride sample as expected, and on the other hand, it can avoid excessive corrosion.
[0089] In this embodiment, the tantalum nitride sample is immersed in a secondary etching solution for 12 minutes. Of course, in other embodiments, other durations within the above-mentioned time range may be used, such as 14 minutes, etc., and this disclosure does not limit this.
[0090] It is worth noting that during the etching of tantalum nitride samples using the secondary etching solution, the state of the secondary etching solution and the condition of the tantalum nitride samples were continuously monitored to ensure that the etching process proceeded as planned.
[0091] Step 207: Remove the tantalum nitride sample from the secondary etching solution and rinse it with deionized water.
[0092] In the above implementation method, the tantalum nitride sample is rinsed with deionized water to remove the secondary corrosion solution remaining on the surface of the tantalum nitride sample.
[0093] Step 208: Dry the tantalum nitride sample to obtain a tantalum nitride film.
[0094] In the above implementation method, the deionized water remaining on the surface of the tantalum nitride sample is dried to obtain the final tantalum nitride film.
[0095] The preparation method provided in this disclosure can improve corrosion uniformity and facilitate control of the corrosion rate. The following is a detailed description:
[0096] Regarding improving corrosion uniformity:
[0097] (1) The uniformity of solution mixing is enhanced.
[0098] Increasing the temperature to 60-70 degrees Celsius accelerates the convection and diffusion processes of the secondary corrosion solution. When heated, the thermal motion of molecules in the secondary corrosion solution becomes more intense. This allows the ammonia and hydrogen peroxide in the secondary corrosion solution to distribute more evenly throughout the reaction system. For example, without heating, the solution may exhibit uneven corrosion due to localized concentration differences; however, at 60-70 degrees Celsius, these concentration differences are reduced due to rapid diffusion, resulting in a more uniform distribution of the etchant on the tantalum nitride surface and thus improving the uniformity of corrosion.
[0099] (2) Uniform activation of reactive sites.
[0100] Tantalum nitride surfaces possess numerous potential reactive sites. At temperatures of 60–70 degrees Celsius, the reactivity of ammonia and hydrogen peroxide increases. On one hand, the hydroxide ions from ammonia ionization can interact more effectively with the metal atoms on the tantalum nitride surface; simultaneously, the reactive oxygen species generated by hydrogen peroxide can more uniformly attack the chemical bonds on the tantalum nitride surface. Because the increased temperature causes these reactions to initiate more synchronously at various locations on the tantalum nitride surface, preventing localized overly rapid or slow reactions, it improves the uniformity of corrosion.
[0101] Regarding aspects that are beneficial for controlling corrosion rate:
[0102] (1) Application of the Arrhenius formula.
[0103] According to the Arrhenius equation, temperature is a crucial factor affecting the reaction rate constant. In this system, when the temperature stabilizes at 60-70 degrees Celsius, the reaction rate constant stabilizes at a relatively predictable value. This is because the rate of increase in reaction rate with increasing temperature is based on the quantitative relationship of this equation. By keeping conditions such as temperature, ammonia concentration, and hydrogen peroxide concentration relatively stable, the corrosion rate can be roughly estimated and controlled using these parameters. For example, if the corrosion rate is found to be too rapid, the temperature or the concentrations of ammonia and hydrogen peroxide can be appropriately reduced to adjust it.
[0104] (2) The observability of the reaction process is enhanced.
[0105] At 60-70 degrees Celsius, the reaction rate is moderate; it is neither too low, making the corrosion process too slow to observe, nor too high, causing the reaction to complete instantly and become uncontrollable. These temperature conditions allow researchers to monitor the corrosion process in real time. The corrosion process can be tracked by observing changes in solution color, gas generation, or measuring the mass loss of tantalum nitride. Furthermore, the reaction conditions can be adjusted promptly based on the observations, thus effectively controlling the corrosion rate.
[0106] Unless otherwise defined, the technical or scientific terms used herein shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” “third,” and similar terms used in this patent application specification and claims do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Similarly, the terms “an” or “a” and similar terms do not indicate a quantity limitation, but rather indicate the presence of at least one. The terms “comprising” or “including” and similar terms mean that the elements or objects preceding “comprising” or “including” encompass the elements or objects listed following “comprising” or “including” and their equivalents, and do not exclude other elements or objects. The terms “connected” or “linked” and similar terms are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. The terms “upper,” “lower,” “left,” “right,” etc., are used only to indicate relative positional relationships; when the absolute position of the described objects changes, the relative positional relationship may also change accordingly.
[0107] The above description is merely an optional embodiment of this disclosure and is not intended to limit this disclosure. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of this disclosure should be included within the protection scope of this disclosure.
Claims
1. A method for preparing a tantalum nitride thin film, characterized in that, The preparation method includes: A primary etching solution is provided, wherein the primary etching solution is a hydrochloric acid solution, and the primary etching solution is used to dissolve tantalum pentoxide on the surface of the tantalum nitride sample; The tantalum nitride sample was immersed in the primary corrosion solution; A secondary corrosion solution is provided by mixing ammonia, hydrogen peroxide, and pure water in a ratio of 1:4:
20. The tantalum nitride sample was immersed in the secondary etching solution for 10-15 minutes to etch a tantalum nitride film.
2. The preparation method according to claim 1, characterized in that, Immersing the tantalum nitride sample in the primary etching solution includes: The tantalum nitride sample was immersed in the primary corrosion solution for 3-5 minutes.
3. The preparation method according to claim 1, characterized in that, Immersing the tantalum nitride sample in the primary etching solution further includes: During the immersion of the tantalum nitride sample, the primary etching solution is stirred.
4. The preparation method according to claim 1, characterized in that, After immersing the tantalum nitride sample in the primary etching solution, the process includes: The tantalum nitride sample was removed from the primary etching solution; The tantalum nitride sample was rinsed with deionized water.
5. The preparation method according to claim 1, characterized in that, Before immersing the tantalum nitride sample in the secondary etching solution, the following steps are included: Adjust the temperature of the secondary corrosion solution to 60-70 degrees Celsius.
6. The preparation method according to claim 1, characterized in that, After immersing the tantalum nitride sample in the secondary etching solution, the process includes: The tantalum nitride sample was removed from the secondary etching solution; The tantalum nitride sample was rinsed with deionized water.
7. The preparation method according to claim 6, characterized in that, After rinsing the tantalum nitride sample with deionized water, the following steps are taken: The tantalum nitride sample was dried to obtain a tantalum nitride film.