Method of forming thin film and method of forming capping layer

Abstract

A method of forming a thin film according to an embodiment of the present invention may include: forming a ruthenium electrode formed of a ruthenium (Ru) metal film on one side of a substrate; and forming a capping layer on the ruthenium electrode, in which the step of forming the capping layer may include spraying a precursor including ruthenium (Ru) toward the ruthenium electrode and spraying a reaction gas including nitrogen (N) toward the ruthenium electrode. Accordingly, according to an embodiment of the present invention, at least one of a ruthenium nitride (RuN) capping layer and a ruthenium oxynitride (RuON) capping layer is formed on an upper portion of a ruthenium (Ru) metal film. Therefore, oxidation of the ruthenium (Ru) metal film can be suppressed and prevented, and deterioration of electrical performance of the ruthenium (Ru) metal film due to oxidation can be suppressed or prevented.

Description

Technical Field

[0001] The present disclosure relates to a method for forming a thin film and a method for forming a covering layer, and more particularly to a method for forming a thin film and a method for forming a covering layer capable of suppressing or preventing oxidation of a ruthenium (Ru) metal film. Background Art

[0002] The capacitor includes a lower electrode formed on a substrate, a dielectric film formed on the lower electrode, and an upper electrode formed on the dielectric film. In this case, the upper electrode and the lower electrode may be formed of a metal film.

[0003] However, the metal film may be easily oxidized, causing degradation of the electrical performance of the electrode.

[0004] [Related technical documents]

[0005] (Patent Document 1) Korean registered patent KR10-1060771. Summary of the Invention

[0006] Technical issues

[0007] The present disclosure provides a method for forming a thin film and a method for forming a capping layer, which are capable of improving the electrical properties of a metal film.

[0008] The present invention also provides a method for forming a thin film and a method for forming a covering layer that can suppress or prevent oxidation of a metal film.

[0009] Technical Solution

[0010] According to an exemplary embodiment, a method for forming a thin film includes: forming a ruthenium electrode formed of a ruthenium (Ru) metal film on one side of a substrate; and forming a covering layer on the ruthenium electrode, wherein the step of forming the covering layer includes spraying a precursor containing ruthenium (Ru) toward the ruthenium electrode and spraying a reaction gas containing nitrogen (N) toward the ruthenium electrode.

[0011] According to another exemplary embodiment, a method for forming a thin film includes: forming a ruthenium electrode formed of a ruthenium (Ru) metal film on one side of a substrate; and forming a covering layer on the ruthenium electrode, wherein the step of forming the covering layer includes spraying a precursor containing ruthenium (Ru) toward the ruthenium electrode and spraying a reaction gas containing nitrogen (N) and oxygen (O) toward the ruthenium electrode.

[0012] The step of forming the ruthenium electrode may include spraying a precursor containing ruthenium and spraying a gas containing oxygen (O).

[0013] The method may include spraying a gas containing at least one of hydrogen (H 2 ), ammonia (NH 3 ), and argon (Ar) to generate plasma after completing the spraying of the gas containing oxygen.

[0014] The step of injecting the gas containing oxygen may include generating oxygen plasma.

[0015] The step of forming the capping layer may include forming the capping layer to be thinner than the ruthenium (Ru) metal film.

[0016] According to another exemplary embodiment, a method for forming a covering layer includes: preparing a substrate having a ruthenium (Ru) metal film formed on one side; and forming a covering layer on the ruthenium (Ru) metal film, wherein the step of forming the covering layer includes spraying a precursor containing ruthenium (Ru) toward the ruthenium (Ru) metal film, and spraying a reaction gas containing nitrogen (N) toward the ruthenium (Ru) metal film to form a ruthenium nitride (RuN) covering layer on the ruthenium (Ru) metal film.

[0017] According to another exemplary embodiment, a method for forming a covering layer includes: preparing a substrate having a ruthenium (Ru) metal film formed on one side; and forming a covering layer on the ruthenium (Ru) metal film, wherein the step of forming the covering layer includes spraying a precursor containing ruthenium (Ru) toward the ruthenium (Ru) metal film, and spraying a reaction gas containing nitrogen (N) and oxygen (O) toward the ruthenium (Ru) metal film to form a ruthenium oxynitride (RuON) covering layer on the ruthenium (Ru) metal film.

[0018] Beneficial effects

[0019] Therefore, according to embodiments, at least one of a ruthenium nitride (RuN) capping layer and a ruthenium oxynitride (RuON) capping layer is formed on the upper portion of the ruthenium (Ru) metal film. Therefore, oxidation of the ruthenium (Ru) metal film can be suppressed or prevented, thereby suppressing or preventing degradation of the electrical properties of the ruthenium (Ru) metal film due to oxidation. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] Figure 1 A view showing a state in which a ruthenium (Ru) metal film and a capping layer are formed on a substrate by a method according to an exemplary embodiment;

[0021] Figure 2 is a conceptual diagram for describing a method of forming a cover layer according to an exemplary embodiment;

[0022] Figure 3 A process diagram conceptually illustrating a method of forming a capping layer on a ruthenium (Ru) metal film according to an exemplary embodiment;

[0023] Figure 4 A view showing a state in which a capping layer is formed on a ruthenium (Ru) metal film formed on a substrate having a groove by a method according to an exemplary embodiment; and

[0024] Figure 5is a view conceptually illustrating a capacitor including a cover layer formed by a method according to an exemplary embodiment. DETAILED DESCRIPTION

[0025] Hereinafter, specific embodiments will be described in detail with reference to the accompanying drawings. However, the present invention may be implemented in different forms and should not be construed as limited to the embodiments set forth herein. Rather, these embodiments are provided so that this disclosure will be thorough and complete and will fully convey the scope of the invention to those skilled in the art. In the drawings, dimensions are exaggerated for clarity, and like reference numerals represent like elements throughout.

[0026] Embodiments relate to a method for forming a ruthenium (Ru) metal film and a method for forming a thin film formed on top of the ruthenium (Ru) metal film. In this case, the thin film formed on top of the ruthenium (Ru) metal film can be referred to as a "capping layer" or "capping film." That is, embodiments relate to a method for forming a ruthenium (Ru) metal film and a method for forming a capping layer that can improve the electrical properties of the ruthenium (Ru) metal film. In addition, embodiments relate to a method for forming a capping layer that can improve the electrical properties of an electrode including the ruthenium (Ru) metal film.

[0027] In this case, for example, an electrode including a ruthenium (Ru) metal film may be at least one of the upper electrode and the lower electrode of the capacitor. That is, at least one of the upper electrode and the lower electrode of the capacitor may be formed from a ruthenium (Ru) metal film formed using the method according to the embodiment. In addition, the capacitor may include a covering layer formed to cover at least one of the upper electrode and the lower electrode.

[0028] Figure 1 is a view illustrating a state in which a ruthenium (Ru) metal film and a capping layer are formed on a substrate by a method according to an exemplary embodiment.

[0029] Reference Figure 1 , a ruthenium (Ru) metal film 100 may be formed on the substrate S, and a capping layer 200 may be formed on the ruthenium (Ru) metal film 100 .

[0030] The substrate S may be a wafer, and the wafer may be any one of a Si wafer, a GaAs wafer, and a SiGe wafer. Of course, the substrate S may be formed of any one of glass, metal, plastic, polymer film, or dielectric material.

[0031] The ruthenium (Ru) metal film 100 may be formed on one surface of the substrate S, such as the upper surface of the substrate S. The ruthenium (Ru) metal film 100 may be an electrode of a semiconductor device such as a capacitor. Therefore, the ruthenium (Ru) metal film 100 may be referred to as a "ruthenium electrode."

[0032] For example, the ruthenium (Ru) metal film 100 may be formed by an atomic layer deposition (ALD) method. Hereinafter, a method of forming the ruthenium (Ru) metal film 100 using the atomic layer deposition (ALD) method will be briefly described.

[0033] First, a precursor containing ruthenium (Ru) is sprayed. In this case, for example, the precursor raw material containing ruthenium (Ru) can be ethylcyclopentadienylruthenium ((EtCp)2Ru) (bis(ethylcyclopentadienyl)ruthenium). When the precursor containing ruthenium (Ru) is sprayed as described above, the precursor containing ruthenium (Ru) is deposited or adsorbed on one surface of the substrate S to form a thin film containing ruthenium (hereinafter referred to as a ruthenium metal film).

[0034] When the injection of the precursor is completed, a purge gas is injected into the chamber loaded with the substrate S to perform a first purge. In this case, for example, the purge gas may be argon (Ar).

[0035] On the other hand, the Ru metal film 100 may contain impurities from a precursor. Specifically, the Ru metal film 100 may contain a ligand such as carbon (C), and the ligand may serve as an impurity that increases the resistivity of the Ru metal film 100.

[0036] Therefore, when the first blow-off is completed, a gas containing oxygen (O) (hereinafter referred to as an oxygen-containing gas) is sprayed into the chamber loaded with the substrate S to remove impurities. For example, the oxygen-containing gas can be pure oxygen (O) gas. Of course, the gas is not limited thereto, and different types of oxygen (O)-containing gases can be used.

[0037] When the oxygen-containing gas is injected into the chamber, the oxygen reacts with ligands contained in the ruthenium metal film 100, for example, carbon (C) ligands. That is, a combustion reaction occurs between the oxygen (O) contained in the oxygen-containing gas and the carbon (C) ligands, thereby separating the carbon (C) from the ruthenium metal film 100. In other words, the bonds of the carbon (C) contained in the precursor of the ruthenium metal film 100 are broken, and the carbon (C) falls off the ruthenium metal film 100. Therefore, the amount of ligand impurities such as carbon (C) contained in the ruthenium metal film 100 can be reduced, or the ligand impurities can be removed from the ruthenium metal film 100.

[0038] As described above, when the oxygen-containing gas is sprayed, the temperature inside the chamber is maintained at 200° C. to 400° C., preferably 250° C. to 300° C. Therefore, the combustion reaction between the oxygen (O) contained in the sprayed oxygen-containing gas and the ligand can actively occur. That is, the heat inside the chamber can enable the combustion reaction between the oxygen (O) contained in the oxygen-containing gas and the ligand contained in the ruthenium metal film 100 to actively occur. Therefore, the combustion reaction between the oxygen (O2) contained in the oxygen-containing gas and the ligand contained in the ruthenium (Ru) metal film 100 or the precursor can be described as a thermal reaction.

[0039] The injection of the oxygen-containing gas includes appropriately adjusting the injection flow rate. That is, while removing impurities contained in the ruthenium (Ru) metal film 100, the injection flow rate of the oxygen-containing gas is adjusted to prevent ruthenium oxide from being generated on the ruthenium (Ru) metal film 100. That is, when the oxygen injection flow rate is too low, the effect of removing impurities may not be significant, and when the oxygen injection flow rate is too high, ruthenium oxide may be generated on the ruthenium (Ru) metal film 100. Therefore, while removing impurities contained in the ruthenium (Ru) metal film 100, the injection flow rate of the oxygen-containing gas is appropriately adjusted to prevent ruthenium oxide from being generated on the ruthenium (Ru) metal film 100.

[0040] When the injection of the oxygen-containing gas is completed, the chamber is purged by injecting a purge gas into the chamber (secondary purge). In this case, the purge gas may be the same as the gas used in the first purge, for example, Ar gas may be used.

[0041] Thus, the method for forming a ruthenium metal film may include spraying a precursor, a primary purge, spraying an oxygen-containing gas, and a secondary purge. Furthermore, the method for forming a ruthenium metal film may include a process cycle, wherein the process cycle may include spraying a precursor, a primary purge, spraying an oxygen-containing gas, and a secondary purge. Furthermore, in the process cycle, at least one of the primary purge and the secondary purge may be skipped.

[0042] The target ruthenium (Ru) metal film can be formed by repeating the process cycle multiple times. In this case, the ruthenium (Ru) metal film 100 can be formed to have, for example, to thickness.

[0043] In addition, the method for forming a ruthenium (Ru) metal film may include forming an oxygen plasma. That is, after the injection of the precursor or the first blowing is completed, when the oxygen-containing gas is injected, an oxygen plasma can be formed. In order to achieve the above-mentioned task, while injecting the oxygen-containing gas into the chamber, a radio frequency (RF) power is applied to at least one of the base on which the substrate S is placed inside the chamber and the injection portion that injects the gas into the chamber. Therefore, a plasma containing oxygen (that is, an oxygen plasma) can be generated inside the chamber. Therefore, the substrate S with the ruthenium (Ru) metal film 100 formed thereon is exposed to the oxygen plasma so that the impurities react with the oxygen. In this case, the impurities such as carbon (C) contained in the ruthenium (Ru) metal film 100 react with oxygen to be converted into gas and detached from the ruthenium (Ru) metal film 100. Therefore, the amount of the impurities such as carbon (C) contained in the ruthenium (Ru) metal film can be reduced, so that the resistivity of the ruthenium (Ru) metal film 100 is reduced.

[0044] In addition, the method of forming the ruthenium metal film may further include forming a plasma. That is, the plasma may be formed after spraying the oxygen-containing gas, while spraying the oxygen-containing gas, or after completing the secondary purge.

[0045] To achieve the above tasks, radio frequency (RF) power is applied to at least one of a susceptor on which the substrate S is placed within the chamber and an injection unit that injects gas into the chamber. Furthermore, a gas containing at least one of hydrogen (H2), ammonia (NH3), or argon (Ar) is used as a plasma-generating gas. As described above, when RF power is applied and the plasma-generating gas is injected, plasma can be generated within the chamber. Thus, the substrate S having the ruthenium (Ru) metal film 100 formed thereon is exposed to the plasma.

[0046] On the other hand, even if the injection of the oxygen-containing gas is completed or the oxygen plasma is formed while the oxygen-containing gas is injected, impurities that have not been removed may still remain in the ruthenium metal film 100. Therefore, after the injection of the oxygen-containing gas is completed, the oxygen plasma is formed while the oxygen-containing gas is injected, or the secondary purge is performed, the impurities that have not been removed can be further removed by additionally forming a plasma. In this case, impurities such as carbon (C) contained in the ruthenium (Ru) metal film 100 are converted into gas by the plasma and are separated from the ruthenium (Ru) metal film 100. Therefore, the amount of impurities such as carbon (C) contained in the ruthenium (Ru) metal film is reduced, so that the resistivity of the ruthenium (Ru) metal film 100 is reduced.

[0047] In this way, after completing the injection of the oxygen-containing gas, forming the oxygen plasma while injecting the oxygen-containing gas, or performing the secondary purge, the amount of impurities contained in the ruthenium metal film 100 can be further reduced by additionally forming the plasma. Therefore, the resistivity of the ruthenium metal film 100 can be further reduced.

[0048] The above-mentioned "spraying a precursor, first blowing, spraying an oxygen-containing gas, second blowing, and forming a plasma" can be performed as one process cycle. As another example, "spraying a precursor, first blowing, forming an oxygen plasma while spraying an oxygen-containing gas, second blowing, and forming a plasma" can be performed as one process cycle. In addition, in the above-mentioned process cycle, at least one of the first blowing and the second blowing can be skipped. In addition, the target ruthenium (Ru) metal film can be formed by repeating the process cycle multiple times. In this case, the ruthenium (Ru) metal film 100 can be formed to have, for example to thickness.

[0049] As described above, a method for forming a ruthenium (Ru) metal film using atomic layer deposition (ALD) is provided. However, the present embodiment is not limited thereto, and the ruthenium (Ru) metal film 100 can be formed by various methods. For example, the ruthenium (Ru) metal film 100 can be formed by any one of chemical vapor deposition (CVD), thermal evaporation deposition, and physical vapor deposition (PVD). In addition, when the ruthenium (Ru) metal film 100 is formed by a physical vapor deposition (PVD) method, the ruthenium (Ru) metal film 100 can be formed, for example, by sputtering.

[0050] On the other hand, the Ru metal film 100 may be oxidized, and the oxidation of the Ru metal film 100 may degrade its electrical properties. For example, oxidation may cause the resistivity of the Ru metal film 100 to increase.

[0051] Therefore, in an embodiment, after forming the ruthenium (Ru) metal film 100, a capping layer 200 is formed on the ruthenium (Ru) metal film 100. That is, the capping layer 200 is formed to cover at least a portion of the ruthenium (Ru) metal film 100. In this case, the capping layer 200 can be formed of a nitride film containing ruthenium (Ru) or a nitride oxide film containing ruthenium (Ru). That is, the capping layer 200 can include a ruthenium nitride (RuN) capping layer formed of ruthenium nitride (RuN) or a ruthenium oxynitride (RuON) capping layer formed of ruthenium oxynitride (RuON). Specifically, the capping layer 200 can be a ruthenium nitride (RuN) capping layer or a ruthenium oxynitride (RuON) capping layer. Such a capping layer 200 is formed to cover at least a portion of the ruthenium (Ru) metal film 100, thereby suppressing or preventing oxidation of the ruthenium (Ru) metal film 100. That is, the capping layer 200 protects the ruthenium (Ru) metal film 100 to suppress or prevent oxidation of the ruthenium (Ru) metal film 100. Therefore, the capping layer 200 can be referred to as a protective layer or a protective film. In addition, the capping layer 200 can be referred to as a capping film.

[0052] In the following, reference will be made to Figures 1 to 3 A method of forming a ruthenium nitride (RuN) capping layer as the capping layer 200 according to Embodiment 1 on the ruthenium (Ru) metal film 100 will be described.

[0053] Figure 2 is a conceptual diagram for describing a method of forming a capping layer according to an exemplary embodiment. Figure 3 FIG. 1 is a process diagram conceptually illustrating a method of forming a capping layer on a ruthenium (Ru) metal film according to an exemplary embodiment.

[0054] exist Figure 2 In the present invention, "on" may refer to spraying a raw material or gas for forming a thin film, and "off" may refer to stopping or terminating the spraying of the raw material or gas.

[0055] Reference Figure 2 and Figure 3 The method of forming the capping layer 200 on the ruthenium (Ru) metal film 100 may include spraying a precursor including ruthenium (Ru) (precursor spraying) and spraying a reaction gas including nitrogen (N) after spraying the precursor (reaction gas spraying).

[0056] In addition, the method of forming the capping layer 200 may further include injecting a purge gas between the precursor injection and the reactant injection (primary purge) and injecting a purge gas after the reaction gas injection (secondary purge). In this case, Ar gas may be used as the purge gas.

[0057] In addition, "precursor injection-primary purge-reactive gas injection-secondary purge" can be performed as one process cycle CY for forming the capping layer 200. In this case, at least one of the primary purge and the secondary purge in the process cycle CY can be skipped. Then, as shown in FIG. Figure 1 As shown, the process cycle CY may be repeated one or more times to form a capping layer 200 on the ruthenium (Ru) metal film 100 .

[0058] In addition, the method for forming the capping layer 200 may further include generating hydrogen plasma after the reaction gas injection or the secondary purge. In this case, "precursor injection - primary purge - reaction gas injection - secondary purge - hydrogen plasma generation" may be performed as a process cycle CY for forming the capping layer 200.

[0059] The number of repetitions of the process cycle CY can be adjusted according to the target thickness to be formed. In this case, the capping layer 200 can be formed thinner than the ruthenium (Ru) metal film 100. The thickness of the capping layer 200 can be 5% to 15%, preferably 8% to 12% of the thickness of the ruthenium (Ru) metal film 100. As a more specific example, the ruthenium (Ru) metal film 100 can have to In this case, the cover layer 200 may be formed to have a thickness of to The thickness, preferably to

[0060] Hereinafter, each process of the process cycle CY will be described in more detail.

[0061] In the precursor injection, a precursor containing ruthenium (Ru) is injected toward the substrate S. That is, the precursor containing ruthenium (Ru) is injected into the chamber loaded with the substrate S. In this case, for example, the precursor raw material containing ruthenium (Ru) can be ethylcyclopentadienylruthenium ((EtCp)2Ru) (bis(ethylcyclopentadienyl)ruthenium). Figure 3 As shown in (a), when the precursor containing ruthenium (Ru) is sprayed in this manner, the precursor is deposited or adsorbed on one side of the substrate S to form a thin film containing ruthenium (Ru) (hereinafter, referred to as a ruthenium (Ru)-containing layer 210).

[0062] When the injection of the precursor is completed, a purge gas is injected into the chamber loaded with the substrate S to perform a first purge. In this case, for example, the purge gas may be argon (Ar).

[0063] When the first blowdown is completed, a reaction gas containing nitrogen (N) is sprayed into the chamber loaded with the substrate S. In this case, the reaction gas containing nitrogen (N) may be a gas containing at least one of ammonia (NH3) and nitrogen (N2). Of course, the reaction gas containing nitrogen (N) is not limited to the above examples, and various types of gases containing nitrogen (N) may be used. When the reaction gas containing nitrogen (N) is sprayed, the ruthenium (Ru) containing layer 210 is exposed to the reaction gas. Therefore, as Figure 3 As shown in (b), nitrogen (N) contained in the reaction gas reacts with the ruthenium (Ru) containing layer 210 to form a ruthenium nitride (Ru) thin film. In other words, a capping layer 200 formed of ruthenium nitride (RuN) is formed on the ruthenium (Ru) metal film 100.

[0064] When the injection of the reaction gas is completed, a purge gas is injected into the chamber loaded with the substrate S for secondary purge. In this case, the purge gas may be the same as that used in the first purge, for example, argon (Ar) may be used.

[0065] In addition, after the secondary purge is completed, a hydrogen plasma can be generated inside the chamber loaded with the substrate S. To achieve the above task, a gas containing hydrogen (H2) is sprayed toward the interior of the chamber or the substrate S, and power for generating the plasma is supplied. For example, radio frequency (RF) power is applied to at least one of a susceptor on which the substrate S is placed inside the chamber and an injection unit that injects gas into the chamber. As described above, when RF power is applied and a gas containing hydrogen (H2) is injected, a plasma containing hydrogen (that is, a hydrogen plasma) can be generated inside the chamber.

[0066] The process cycle CY including the precursor injection, primary purge, reaction gas injection, and secondary purge as described above may be repeated one or more times. That is, the process cycle CY may be repeated one or more times depending on the target thickness of the capping layer 200. In addition, the process cycle CY may further include the generation of hydrogen plasma as described above, and the process cycle CY may be repeated one or more times.

[0067] Thus, in an embodiment, after forming the ruthenium (Ru) metal film 100, the ruthenium nitride (RuN) capping layer 200 is formed to cover the ruthenium (Ru) metal film 100. Therefore, the ruthenium nitride (RuN) capping layer 200 suppresses or prevents the ruthenium (Ru) metal film 100 from being exposed. Therefore, the ruthenium nitride (RuN) capping layer 200 can suppress or prevent the ruthenium (Ru) metal film 100 from being oxidized.

[0068] In addition, the ruthenium (Ru) metal film 100 is formed thicker (for example, formed to have to The thickness of the Ruthenium (Ru) metal film 100 is 200, and the Ruthenium nitride (RuN) capping layer 200 is formed to be as thin as 5% to 15% of the thickness of the Ruthenium (Ru) metal film 100. Therefore, when the Ruthenium (Ru) metal film 100 is used as an electrode, even when the Ruthenium nitride (RuN) capping layer 200 is formed on the Ruthenium (Ru) metal film 100, the Ruthenium nitride (RuN) capping layer (200) still has no or almost no insulation function. That is, when the Ruthenium (Ru) metal film 100, the Ruthenium nitride (RuN) capping layer 200 and the conductive film are stacked in this order, the Ruthenium nitride (RuN) capping layer 200 does not provide insulation between the Ruthenium (Ru) metal film 100 and the conductive film. That is, even when the ruthenium nitride (RuN) capping layer 200 is formed between the ruthenium (Ru) metal film 100 and the conductive film, the ruthenium (Ru) metal film 100 and the conductive film can be conductive. Therefore, the ruthenium nitride (RuN) capping layer 200 formed on the ruthenium (Ru) metal film 100 can suppress or prevent the oxidation of the ruthenium (Ru) metal film 100, and can also enable the ruthenium (Ru) metal film 100 to be conductive without being insulated from other films.

[0069] As described above, a method for forming a ruthenium nitride (RuN) capping layer 200 on a ruthenium (Ru) metal film 100 is provided. Figures 1 to 3 A method of forming a ruthenium oxynitride (RuON) capping layer according to Example 2 on the ruthenium (Ru) metal film 100 will be described.

[0070] The method of forming the RuON capping layer on the Ru metal film 100 may include spraying a precursor containing Ru (precursor spraying) and spraying a reaction gas containing nitrogen (N) and oxygen (O) after spraying the precursor (reaction gas spraying).

[0071] Furthermore, the method of forming the RuON capping layer may further include injecting at least one of a purge gas between the precursor injection and the reactant injection (primary purge) and a purge gas after the reactant gas injection (secondary purge).

[0072] In addition, “precursor injection-primary purge-reactive gas injection-secondary purge” can be performed as a process cycle CY for forming the capping layer 200. Then, as Figure 1 As shown, the process cycle CY can be repeated one or more times to form a ruthenium oxynitride (RuON) capping layer on the ruthenium (Ru) metal film. In this case, the number of repetitions of the process cycle CY can be adjusted according to the target thickness of the ruthenium oxynitride (RuON) capping layer to be formed.

[0073] In the formation of the ruthenium oxynitride (RuON) capping layer 200, the ruthenium oxynitride (RuON) capping layer 200 is formed thinner than the ruthenium (Ru) metal film 100. In this case, the thickness of the ruthenium oxynitride (RuON) capping layer 200 is formed to be 5% to 15%, preferably 8% to 12% of the thickness of the ruthenium (Ru) metal film 100. As a more specific example, the ruthenium (Ru) metal film 100 may have to and in this case, the ruthenium oxynitride (RuON) capping layer 200 is formed to have a thickness of to The thickness, preferably to

[0074] The method for forming a ruthenium oxynitride (RuON) capping layer (Example 2) differs from the method for forming a ruthenium nitride (RuON) capping layer (Example 1) only in the type of reaction gas used, and the other processes are performed in the same manner. Therefore, hereinafter, the reaction gas injection will be described, and the description of the precursor injection and the primary and secondary purges will be skipped. In addition, when describing the reaction gas injection, the content repeated in Example 1 will be skipped or briefly described.

[0075] After the precursor injection is completed or after the first blow-off is completed, the reaction gas injection is performed. That is, the reaction gas is injected into the chamber loaded with the substrate S. In this case, a gas containing oxygen (O) and nitrogen (N) is used as the reaction gas. In this case, for example, O2 gas can be used as the gas containing oxygen (O). In addition, at least one of ammonia (NH3) and nitrogen (N2) can be used as the gas containing nitrogen (N). Of course, the gas containing oxygen (O) and the gas containing nitrogen (N) are not limited to the above examples, and other gases containing oxygen (O) and other gases containing nitrogen (N) can be used as reaction gases.

[0076] When a precursor containing ruthenium (Ru) is sprayed during the precursor spraying, the precursor is adsorbed or deposited on the ruthenium (Ru) metal film 100 to form a ruthenium (Ru)-containing layer 210. Thereafter, when a reaction gas containing oxygen (O) and nitrogen (N) is sprayed toward the substrate S, the ruthenium (Ru)-containing layer 210 reacts with the reaction gas. That is, the ruthenium (Ru) contained in the ruthenium (Ru)-containing layer 210 reacts with the oxygen (O) and nitrogen (N) contained in the reaction gas. As a result, the ruthenium (Ru)-containing layer 210 is oxidized and nitrided, thereby converting into ruthenium oxynitride (RuON). In other words, a capping layer 200 formed of ruthenium oxynitride (RuON) is formed on the ruthenium (Ru) metal film 100.

[0077] Thus, in Example 2, the ruthenium oxynitride (RuON) capping layer 200 is formed on the ruthenium (Ru) metal film 100. Therefore, the ruthenium (Ru) metal film 100 is covered by the ruthenium oxynitride (RuON) capping layer 200. Therefore, exposure of the ruthenium (Ru) metal film 100 can be suppressed or prevented, and oxidation of the ruthenium (Ru) metal film 100 can be suppressed or prevented.

[0078] Figure 4 is a view illustrating a state in which a capping layer is formed on a ruthenium (Ru) metal film formed on a substrate having a groove by a method according to an exemplary embodiment.

[0079] Figure 1 and Figure 3 The embodiment is described as forming a capping layer on a ruthenium (Ru) metal film formed on a flat substrate without a groove. However, the embodiment is not limited thereto. Figure 4 As shown, a ruthenium (Ru) metal film 100 is formed on a substrate S having a trench (T), and a capping layer 200 may be formed on the ruthenium (Ru) metal film 100. This will be described in more detail below.

[0080] like Figure 4 As shown, the substrate S may have a hole (that is, a trench T) formed to penetrate a portion of the substrate S in the vertical direction. In addition, a ruthenium (Ru) metal film 100 may be formed on the upper surface of the substrate S and on the peripheral wall surrounding the trench T. Specifically, the ruthenium (Ru) metal film 100 may be formed on the bottom surface of the trench T of the substrate S, the side surface of the trench T, and the upper surface which is the outer surface of the trench T. In addition, as Figure 4 As shown, a ruthenium nitride capping layer 200 or a ruthenium oxynitride capping layer 200 may be formed on the ruthenium (Ru) metal film 100 .

[0081] As described above, in forming the capping layer 200 on the ruthenium (Ru) metal film 100, a ruthenium nitride (RuN) capping layer or a ruthenium oxynitride (RuON) capping layer is formed. However, the present embodiment is not limited thereto, and the capping layer 200 may be formed by stacking a ruthenium nitride (RuN) capping layer and a ruthenium oxynitride (RuON) capping layer. That is, the capping layer 200 formed on the ruthenium (Ru) metal film 100 may include a ruthenium nitride (RuN) capping layer and a ruthenium oxynitride (RuON) capping layer. In this case, the ruthenium nitride (RuN) capping layer and the ruthenium oxynitride (RuON) capping layer may be formed to be alternately stacked.

[0082] Figure 5 is a view conceptually illustrating a capacitor including a cover layer formed by a method according to an exemplary embodiment.

[0083] In the following, reference will be made to Figure 5100 . A capacitor including the capping layer 200 according to an embodiment will be described. In this case, a case where the lower electrode of the capacitor 1000 is formed of a ruthenium (Ru) metal film and the capping layer 200 according to an embodiment is formed on an upper portion of the lower electrode 100 will be described as an example. Therefore, hereinafter, for ease of description, the reference numeral of the lower electrode will be referred to as "100," which is the same as the reference numeral of the ruthenium (Ru) metal film.

[0084] Reference Figure 5 The capacitor 1000 may include a substrate S, a lower electrode 100 formed on the substrate S and formed of a ruthenium (Ru) metal film, a capping layer 200 formed on the lower electrode 100, a dielectric film 300 formed on the capping layer 200, and an upper electrode 400 formed on the dielectric film 300. In addition, the capacitor 1000 may further include a contact layer (not shown) formed below the lower electrode 100.

[0085] In this case, the substrate S may be a wafer, and the wafer may be any one of a Si wafer, a GaAs wafer, and a SiGe wafer. Of course, the substrate S may be formed of any one of glass, metal, plastic, polymer film, and dielectric material.

[0086] The lower electrode 100 may be formed on one surface of the substrate, for example, the upper surface of the substrate, and may be formed of a ruthenium (Ru) metal film as described above. Furthermore, a contact layer may be formed below the lower electrode 100, that is, between the substrate S and the lower electrode 100. In this case, the contact layer may be formed of a metal oxide, for example, a SiO2 film or an Al2O3 film.

[0087] The capping layer 200 may be formed to cover at least a portion of the lower electrode 100 formed of a ruthenium (Ru) metal film. In addition, the capping layer 200 may be formed of a ruthenium nitride (RuN) capping layer or a ruthenium oxynitride (RuON) capping layer.

[0088] The dielectric film 300 may be formed on the capping layer 200 and may be formed of a dielectric material including a metal oxide. As a more specific example, the dielectric film 300 may be formed of any one of ZrO2, Al2O3, TiO2, TaO2, and HfO2. Furthermore, the dielectric film 300 may be formed using atomic layer deposition (ALD) or chemical vapor deposition (CVD).

[0089] The upper electrode 400 may be formed on the upper portion of the dielectric film 300 and may be formed of various conductive materials. In this case, the upper electrode 400 may be formed of a ruthenium (Ru) metal film or a different metal film other than ruthenium (Ru).

[0090] The ruthenium nitride (RuN) capping layer 200 or the ruthenium oxynitride (RuON) capping layer 200 is formed on the upper portion of the lower electrode 100 of the capacitor 1000. Therefore, oxidation of the lower electrode 100 caused by the ruthenium nitride (RuN) capping layer 200 or the ruthenium oxynitride (RuON) capping layer 200 can be suppressed or prevented. Therefore, an increase in electrical properties such as resistivity of the lower electrode 100 caused by oxidation can be suppressed or prevented.

[0091] Although not shown, a capping layer may be formed on the upper electrode 400 , and the capping layer may be formed of a ruthenium nitride (RuN) capping layer or a ruthenium oxynitride (RuON) capping layer.

[0092] Furthermore, as described above, the lower electrode 100 is formed of a ruthenium (Ru) metal film, and the capping layer 200 is formed on the lower electrode 100. However, the present embodiment is not limited thereto, and the upper electrode 400 may be formed of a ruthenium (Ru) metal film, and a ruthenium nitride (RuN) capping layer or a ruthenium oxynitride (RuON) capping layer may be formed on the upper portion of the upper electrode 400. In this case, the lower electrode 100 may be formed of a different metal film other than ruthenium (Ru), and the capping layer 200 may not be formed between the lower electrode 100 and the dielectric film 300. Of course, the lower electrode 100 may be formed of a different metal film other than ruthenium (Ru), and the capping layer 200 may be formed on the lower electrode 100. Furthermore, the lower electrode 100 and the upper electrode 400 may each be formed of a ruthenium (Ru) metal film, and the capping layer 200 may be formed between the lower electrode 100 and the dielectric film 300 and on the upper portion of the upper electrode 400.

[0093] As described above, in forming the capping layer 200 on at least one of the lower electrode 100 and the upper electrode 400, a ruthenium nitride (RuN) capping layer or a ruthenium oxynitride (RuON) capping layer is formed. However, the present embodiment is not limited thereto, and the capping layer 200 may be formed by stacking a ruthenium nitride (RuN) capping layer and a ruthenium oxynitride (RuON) capping layer. That is, the capping layer 200 formed on at least one of the lower electrode 100 and the upper electrode 400 may include a ruthenium nitride (RuN) capping layer and a ruthenium oxynitride (RuON) capping layer. In this case, the ruthenium nitride (RuN) capping layer and the ruthenium oxynitride (RuON) capping layer may be formed to be alternately stacked.

[0094] Furthermore, as described above, a ruthenium nitride (RuN) capping layer or a ruthenium oxynitride (RuON) capping layer is formed to cover at least one of the upper electrode 400 and the lower electrode 100 of the capacitor 1000. However, the capping layer 200 formed by the method according to the embodiment is not limited to the electrode of the capacitor 1000 and can be applied to various semiconductor devices or electronic devices provided with electrodes.

[0095] Industrial Applicability

[0096] Therefore, according to embodiments, at least one of a ruthenium nitride (RuN) capping layer and a ruthenium oxynitride (RuON) capping layer is formed on top of the ruthenium (Ru) metal film. Therefore, oxidation of the ruthenium (Ru) metal film can be suppressed or prevented, thereby suppressing or preventing degradation of the electrical properties of the ruthenium (Ru) metal film due to oxidation.

Claims

1. A method for forming a thin film, the method comprising: forming a ruthenium electrode formed of a ruthenium (Ru) metal film on one side of the substrate; as well as forming a capping layer on the ruthenium electrode, The step of forming the covering layer includes: spraying a precursor containing ruthenium (Ru) toward the ruthenium electrode; and A reaction gas containing nitrogen (N) is sprayed toward the ruthenium electrode.

2. A method for forming a thin film, the method comprising: forming a ruthenium electrode formed of a ruthenium (Ru) metal film on one side of the substrate; as well as forming a capping layer on the ruthenium electrode, The step of forming the covering layer includes: spraying a precursor containing ruthenium (Ru) toward the ruthenium electrode; and A reaction gas containing nitrogen (N) and oxygen (O) is sprayed toward the ruthenium electrode.

3. The method according to claim 1 or 2, wherein The steps of forming the ruthenium electrode include: injecting a precursor comprising ruthenium; and A gas containing oxygen (O) is injected. 4 . The method of claim 3 , comprising injecting a gas containing at least one of hydrogen (H 2 ), ammonia (NH 3 ), and argon (Ar) to generate plasma after completing the injection of the gas containing oxygen.

5. The method according to claim 3, wherein: The step of injecting the gas containing oxygen includes generating oxygen plasma.

6. The method according to claim 1 or 2, wherein: The step of forming the capping layer includes forming the capping layer to be thinner than the ruthenium (Ru) metal film.

7. A method for forming a covering layer, the method comprising: preparing a substrate having a ruthenium (Ru) metal film formed on one side; as well as forming a capping layer on the ruthenium (Ru) metal film, The step of forming the covering layer includes: spraying a precursor containing ruthenium (Ru) toward the ruthenium (Ru) metal film; and A reaction gas containing nitrogen (N) is sprayed toward the ruthenium (Ru) metal film to form a ruthenium nitride (RuN) capping layer on the ruthenium (Ru) metal film.

8. A method for forming a covering layer, the method comprising: preparing a substrate having a ruthenium (Ru) metal film formed on one side; as well as forming a capping layer on the ruthenium (Ru) metal film, The step of forming the covering layer includes: spraying a precursor containing ruthenium (Ru) toward the ruthenium (Ru) metal film; and A reaction gas containing nitrogen (N) and oxygen (O) is sprayed toward the ruthenium (Ru) metal film to form a ruthenium oxynitride (RuON) capping layer on the ruthenium (Ru) metal film.

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