Method for forming metal nitride thin film

Abstract

A method for forming a metal nitride thin film according to an embodiment includes the steps of: preparing a substrate in a process chamber in which a processing space is formed; forming a metal nitride thin film on the upper portion of the substrate by supplying a metal precursor gas and a nitrogen-containing gas, respectively; supplying a hydrogen-containing gas to the process chamber to form a first plasma to perform at least one first surface treatment on the metal nitride thin film; and supplying a nitrogen-containing gas to the process chamber, forming a second plasma, and performing at least one second surface treatment on the substrate subjected to the first surface treatment.

Description

Technical Field

[0001] The present invention relates to a method for forming a metal nitride thin film. Background Art

[0002] Recently, with the miniaturization and high integration of semiconductor devices, the demand for methods that can reduce the number and size of particles and improve film quality is increasing. In particular, for metal nitride films such as titanium nitride films, film quality and yield management have become more important.

[0003] Generally speaking, the metal nitride film is formed by chemical vapor deposition (CVD) in which a metal source gas and a nitrogen-containing gas are supplied into a reaction chamber to generate a thermal reaction to form a thin film on a substrate. Immediately after the metal nitride film is deposited, hydrogen plasma is used to remove the metal precursor residue with a slower flow rate to improve the residue and particle level in the film quality.

[0004] However, when a thick metal nitride thin film is formed by the conventional method, cracks are easily formed on the thin film due to high pressure, and there is a problem of forming a film with high resistance, so it is necessary to study a method that can improve it. Summary of the invention

[0005] Technical issues to be solved

[0006] According to one embodiment, an object of the present invention is to provide a technical content of a method for forming a metal nitride thin film, which has low pressure and resistance even when forming a thicker metal nitride thin film, and can prevent defects such as cracks from occurring.

[0007] Means of solving the problem

[0008] The method for forming a metal nitride film according to an embodiment of the present invention includes the following steps: preparing a substrate in a process chamber that forms a processing space; supplying a metal precursor gas and a nitrogen-containing gas respectively to form a metal nitride film on the upper part of the substrate; supplying a hydrogen-containing gas to the process chamber to form a first plasma and performing at least one first surface treatment on the metal nitride film; and supplying a nitrogen-containing gas to the process chamber to form a second plasma and performing at least one second surface treatment on the substrate that has completed the first surface treatment.

[0009] According to one embodiment, the step of forming the metal nitride film on the upper portion of the substrate is performed by a thermal chemical vapor deposition (thermal CVD) method performed at a temperature of 300 to 800° C. to react the metal precursor gas with the nitrogen-containing gas to form the metal nitride film.

[0010] According to one embodiment, the metal nitride film may include one of titanium nitride (TiN), tungsten nitride (WN), molybdenum nitride (Mo2N), tantalum nitride (TaN), aluminum nitride (AlN) and titanium aluminum nitride (TiAlN).

[0011] According to one embodiment, the metal precursor gas may include a metal precursor containing at least one of titanium tetrachloride (TiCl4), tetrakis(dimethylamino)titanium (TDMAT, Ti(N(Me2)4)), tetrakis(diethylamino)titanium (TDEAT, Ti(N(Et2)4)) and tetrakis(ethylmethylamino)titanium (TEMAT, Ti(N(EtMe)4)).

[0012] According to one embodiment, the nitrogen-containing gas may include at least one of ammonia (NH 3 ) and nitrogen (N 2 ).

[0013] According to one embodiment, in the first surface treatment step and the second surface treatment step, dual-frequency power is applied to form the first plasma and the second plasma, respectively. In particular, at least one of high frequency or ultra-high frequency and low frequency are applied to form the first plasma and the second plasma, respectively.

[0014] According to one embodiment, in the second surface treatment step, a hydrogen-containing gas may be supplied in addition to the nitrogen-containing gas.

[0015] Effects of the Invention

[0016] According to the method for forming a metal nitride film of an embodiment of the present invention, a first surface treatment is performed on a metal nitride film deposited by a thermal chemical vapor deposition method using hydrogen plasma to remove a metal precursor gas with a slower flow rate. Through the first surface treatment process, the concentration of residual ions and contaminants in the film of the metal nitride film can be reduced and the level of particulate matter can be improved. In addition, a second surface treatment is performed on the metal nitride film that has completed the first surface treatment using a second plasma. Through the second surface treatment process, the pressure of the metal nitride film is reduced, cracks are prevented, and the surface resistance is reduced. Accordingly, the method for forming a metal nitride film of an embodiment of the present invention can form a metal nitride film with improved electrical, chemical, and physical properties. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 1 is a process diagram showing a method for forming a metal nitride thin film according to an embodiment of the present invention.

[0018] Figure 2 FIG. 1 is a timing chart showing a method for forming a metal nitride thin film according to an embodiment of the present invention.

[0019] Figure 3 This is a graph showing ion energy distribution and ion energy at each frequency in order to explain ion energy formed by plasma in a method for forming a metal nitride thin film according to an embodiment of the present invention.

[0020] Figure 4 1 is a graph showing time-dependent superimposed waves of voltages formed by a dual-frequency power supply in a method for forming a metal nitride thin film according to an embodiment of the present invention.

[0021] Figure 5 This is a graph showing changes in ion energy distribution when a dual-frequency power supply is applied in a method for forming a metal nitride thin film according to an embodiment of the present invention.

[0022] Figure 6 FIG. 1 is a structural diagram showing a substrate processing apparatus according to an embodiment of the present invention.

[0023] Figure 7 : are SIMS data showing the evaluation results of the chloride ion concentration of the thin films formed by the methods of Examples 1 to 3.

[0024] Figure 8 These are electron microscope images of the surfaces of thin films formed by the methods of (a) Comparative Example, (b) Example 1, (c) Example 2, and (d) Example 3.

[0025] (Explanation of Reference Numerals)

[0026] 100: Substrate processing device

[0027] 110: Process chamber

[0028] 120: Gas injection unit

[0029] 130: Substrate placement unit

[0030] 140: Plasma power supply unit

[0031] S: Substrate DETAILED DESCRIPTION

[0032] Figure 1 1 is a process diagram showing a method for forming a metal nitride thin film according to an embodiment of the present invention. Figure 2 This is a timing chart showing an example of a method for forming a metal nitride thin film according to an embodiment of the present invention.

[0033] Reference Figure 1 and Figure 2 The method for forming a metal nitride film according to an embodiment of the present invention includes the following steps: a step S100 of preparing a substrate S in a process chamber 100 forming a processing space; a step S200 of forming a metal nitride film on the upper part of the substrate S; a step S300 of performing a first surface treatment on the metal nitride film; and a step S400 of performing a second surface treatment on the substrate S after the first surface treatment. The method for forming a metal nitride film according to the embodiment can use conventional substrate processing devices of various forms used to form a metal nitride film on a substrate S. In addition, the substrate processing device is used to perform a plasma enhanced chemical vapor deposition process.

[0034] First, in the step S100 of preparing the substrate, the substrate S is placed in a substrate placement portion 130 provided in a processing space of a process chamber.

[0035] The substrate S may be any of various conventional substrates on which a metal nitride thin film is formed for use in manufacturing semiconductor devices.

[0036] Next, in the step S200 of forming the metal nitride thin film, a metal precursor gas and a nitrogen-containing gas are supplied to the substrate S respectively, so that a metal nitride thin film is formed on an upper portion of the substrate S.

[0037] In this step, a metal precursor gas and a nitrogen-containing gas are supplied respectively, so that the metal precursor gas and the nitrogen-containing gas react to form the metal nitride film. In this step, the metal nitride film can be formed by a thermal chemical vapor deposition method. The thermal chemical vapor deposition method is performed at a temperature of 300 to 800° C. In particular, the thermal chemical vapor deposition method is performed at a temperature of 500 to 700° C.

[0038] The metal nitride film may include at least one of titanium nitride (TiN), tungsten nitride (WN), molybdenum nitride (Mo2N), tantalum nitride (TaN), aluminum nitride (AlN) and titanium aluminum nitride (TiAlN).

[0039] The metal precursor gas may be any of a variety of conventional metal precursor gases used to form a metal nitride thin film.

[0040] In particular, the metal nitride film may be a titanium nitride film. Accordingly, the metal precursor gas may include a metal precursor including at least one of titanium tetrachloride (TiCl4), tetrakis(dimethylamino)titanium (TDMAT, Ti(N(Me2)4)), tetrakis(diethylamino)titanium (TDEAT, Ti(N(Et2)4)) and tetrakis(ethylmethylamino)titanium (TEMAT, Ti(N(EtMe)4)).

[0041] The nitrogen-containing gas may include at least one of ammonia (NH 3 ) and nitrogen (N 2 ).

[0042] When a metal nitride film is formed by the thermal chemical vapor deposition method, the metal nitride film has problems such as cracks being easily formed on the film due to the high pressure and forming a film with high resistance. In the method for forming a metal nitride film according to an embodiment of the present invention, a PECVD process is used to perform surface treatment on the metal nitride film using a first plasma and a second plasma respectively, thereby forming a metal nitride film with excellent physical properties.

[0043] Next, in the first surface treatment step S300 , a hydrogen-containing gas is supplied to the process chamber 110 to form a first plasma, and a first surface treatment is performed on the metal nitride film.

[0044] In this step, a hydrogen-containing gas is supplied to form a first plasma, and a first surface treatment is performed on the metal nitride film. The first surface treatment can remove the metal precursor residual gas with a slower flow rate, reduce the concentration of residual ions and pollutants in the film of the metal nitride film, and improve the level of particulate matter. The hydrogen-containing gas can be hydrogen (H2) gas.

[0045] In this step, in order to perform the first surface treatment on the metal nitride film, at least one of a low frequency power (LF), a high frequency power (HF) and a very high frequency power (VHF) is applied to form the first plasma.

[0046] According to one embodiment, in this step, the first plasma is formed by applying a dual-frequency power supply. The first plasma may be formed by applying a high frequency (HF) power supply and a low frequency (LF) power supply. Alternatively, the first plasma may be formed by applying a very high frequency (VHF) power supply and a low frequency (LF) power supply. Furthermore, the first plasma may also be formed by applying a very high frequency (VHF) power supply and a high frequency (HF) power supply. In particular, the first plasma may also be formed by applying a very high frequency (VHF) power supply and a high frequency (HF) power supply and a low frequency (LF) power supply.

[0047] According to one embodiment, in this step, hydrogen (H2) gas is supplied to the upper part of the metal nitride film. Furthermore, a low frequency (LF) power supply of 460 kHz or less and a high frequency (HF) power supply of 13.56 MHz are simultaneously applied to form a first plasma. Furthermore, the first surface treatment is performed on the metal nitride film for 0.01 to 60 seconds using the first plasma.

[0048] Furthermore, in this step, the first surface treatment may be performed n times (where n represents a natural number greater than 1). Specifically, a process of supplying a hydrogen-containing gas to the process chamber to form a first plasma and performing the first surface treatment on the metal nitride film for a certain period of time or longer is performed at least once. If the first surface treatment is performed repeatedly, the residual gas of the metal precursor, the residual ions in the film, and the concentration of pollutants and particulate matter can be more effectively removed.

[0049] Next, in the second surface treatment step S400, the substrate after the first surface treatment is subjected to a second surface treatment. Regarding the second surface treatment, nitrogen-containing gas is supplied to the process chamber 110 to form a second plasma, and a nitridation treatment is performed on the surface of the metal nitride film.

[0050] The second surface treatment can reduce the stress and surface resistance of the metal nitride film, and can prevent cracks from occurring in the metal nitride film.

[0051] Specifically, in this step, a reaction gas, i.e., a nitrogen-containing gas, is supplied to the upper part of the metal nitride film that has completed the first surface treatment to form a second plasma. In particular, in this step, the nitrogen-containing gas and hydrogen are supplied simultaneously to further improve the second surface treatment effect. More specifically, based on the second plasma, nitrogen ions ionized from the nitrogen-containing gas are formed. The metal nitride film that has completed the first surface treatment is exposed to the second plasma, and on its surface, metal precursor ions, impurities contained in the metal precursor, and hydrogen contained in the reaction gas are ionized. The ionized metal precursor ions are combined with the ionized nitrogen ions to form the film quality of the metal nitride film. In addition, the ionized residual impurities are combined with the ionized hydrogen to detach and be removed from the surface of the metal nitride film. Accordingly, the second plasma treatment can reduce the pressure of the metal nitride film, prevent cracks from occurring in the metal nitride film, and reduce the surface resistance of the metal nitride film.

[0052] Meanwhile, in this step, for the second surface treatment, argon gas is continuously supplied while supplying the reaction gas.

[0053] Furthermore, in this step, at least one of a low frequency power source, a high frequency power source, and an ultra-high frequency power source is applied to form the second plasma, and a nitridation treatment is performed on the metal nitride film.

[0054] According to one embodiment, in this step, the second plasma may be formed by applying a dual-frequency power supply. Specifically, the second plasma may be formed by applying a high frequency (HF) power supply and a low frequency (LF) power supply. Alternatively, the second plasma may be formed by applying a very high frequency (VHF) power supply and a low frequency (LF) power supply.

[0055] In particular, in this step, the second plasma is formed by applying a high frequency (HF) power source and a low frequency (LF) power source, because the properties of the film can be further improved by considering the characteristics of the high frequency (HF) power source and the low frequency (LF) power source, namely, the plasma energy and density.

[0056] According to one embodiment, in this step, nitrogen-containing gas is supplied to the upper portion of the metal nitride film, and a low-frequency power supply below 460 kHz and a high-frequency power supply of 13.56 MHz are simultaneously applied to perform a second surface treatment on the metal nitride film for 0.01 to 60 seconds.

[0057] Furthermore, in this step, nitrogen-containing gas is supplied to form a second plasma, and the substrate that has completed the first surface treatment is subjected to m surface treatments (wherein m represents a natural number greater than 1). As described above, as the second surface treatment step S400 is repeatedly performed, the pressure reduction efficiency can be made greater, thereby further improving film cracks and surface resistance.

[0058] In the method for forming a metal nitride thin film of the above-described embodiment, a dual-frequency power source is used to form the first plasma and the second plasma respectively, so that the physical properties of the metal nitride thin film can be further improved.

[0059] Specifically, when the first plasma and the second plasma are used to perform thin film deposition and surface treatment processes, one of the particles that directly acts is ions, which affect the electrical, chemical, and physical properties of the deposited thin film according to their ion energy characteristics.

[0060] Figure 3 This is a graph showing ion energy distribution and ion energy intensity (unit: eV) at each frequency in order to explain ion energy formed by plasma in a method for forming a metal nitride thin film according to an embodiment of the present invention. Figure 4 FIG. 4 is a graph showing a superimposed wave over time of each voltage formed by a dual-frequency power supply in a method for forming a metal nitride thin film according to an embodiment of the present invention. Figure 5 This is a graph showing changes in ion energy distribution when a dual-frequency power supply is applied in a method for forming a metal nitride thin film according to an embodiment of the present invention.

[0061] Generally speaking, when a single-frequency power supply is used to form plasma, the ion energy distribution presents a monomodal or bimodal peak. At this time, the ion energy distribution presents peaks of different modes according to the difference in ion transit time and operating frequency. In addition, according to the operating frequency of the power supply used to form plasma, the electrodes of the sheath will also change.

[0062] In particular, capacitively coupled plasma (CCP) cannot achieve ion energy adjustment while maintaining a certain density characteristic. The capacitively coupled plasma can use power supplies of different frequencies to adjust the plasma density and ion energy. Generally, a low frequency power supply indicates a high ion energy at a lower density. A high frequency indicates a low ion energy at a higher density. An electrode using two different frequencies is called a superimposed electrode. The two frequency power supplies are superimposed to present a superimposed frequency (refer to Figure 4 ).

[0063] Reference Figure 5 When dual plasma is formed using power supplies of different frequencies, as high frequency is applied to low frequency plasma, the plasma density will increase, the thickness of the plasma sheath will decrease, and overall, the ion energy distribution will shift to the low side (refer to Figure 5 (a) and Figure 5 (b)).

[0064] Moreover, when the power of the dual-frequency medium-high frequency power source increases, the ion energy distribution shifts to the low energy. On the contrary, when the power of the dual-frequency medium-low frequency power source increases, the ion energy distribution shifts to the high energy.

[0065] Accordingly, the dual-frequency power supply uses two different frequencies and is converted into a superposition state. Compared with the case of using a single frequency, the dual-frequency power supply can guide the deposition reaction while forming appropriate ion energy and adjusting to an appropriate density. Moreover, by adjusting the power, the characteristics of different frequency bands can be adopted. When the dual-frequency power supply is used, compared with the case of using a single-frequency power supply to form the first plasma, the removal of metal precursor gas, the reduction of the concentration of residual ions and pollutants in the film, and the removal of particulate matter can be improved. At the same time, when the dual-frequency power supply is used, compared with the case of using a single-frequency power supply to form the second plasma, the nitridation treatment effect can be improved and the pressure of the film can be further improved, the occurrence of cracks can be more effectively prevented, and the physical properties of the film can be improved.

[0066] In the method for forming a metal nitride film of the embodiment of the present invention as described above, a first surface treatment is performed on the metal nitride film deposited by a thermal chemical vapor deposition method using hydrogen plasma to remove the metal precursor gas with a slower flow rate. Accordingly, the concentration of residual ions and contaminants in the film of the metal nitride film can be reduced and the level of particulate matter can be improved. In addition, a second plasma is used to perform a nitridation treatment on the metal nitride film that has completed the first surface treatment to reduce the pressure of the film, prevent the generation of cracks, and reduce the surface resistance. Accordingly, a metal nitride film with improved electrical, chemical, and physical properties can be formed.

[0067] In addition, according to the metal nitride film forming method of the embodiment of the present invention, a conventional substrate processing device having various structures used in the plasma enhanced chemical vapor deposition method can be used to form metal nitride thin films respectively. As an example, in the metal nitride film forming method of the embodiment of the present invention, the metal nitride film is formed on the substrate using the following substrate processing device.

[0068] Figure 6 is a structural diagram showing a substrate processing apparatus according to one embodiment.

[0069] Reference Figure 6 The basic components of a substrate processing apparatus 100 according to an embodiment of the present invention may include a process chamber 110 , a gas injection unit 120 , a substrate seating unit 130 , and a plasma power supply unit 140 .

[0070] The process chamber 110 may define a processing space 112 therein. For example, the process chamber 110 may be airtight, exhaust the process gas in the processing space 112, and be connected to a vacuum chamber (not shown in the drawings) through an exhaust port in order to adjust the vacuum degree in the processing space 112. The process chamber 110 may have a variety of shapes. As an example, the process chamber 110 has a structure including a side wall portion defining the processing space 112 and a cover portion located at an upper end of the side wall portion.

[0071] The gas injection unit 120 is provided in the process chamber 110 and supplies the process gas supplied from the outside of the process chamber 110 to the processing space 112. The gas injection unit 120 is provided in the upper part of the process chamber 110 opposite to the substrate placement unit 13, and injects the process gas to the substrate S placed on the substrate placement unit 130. The gas injection unit 120 may include at least one inflow hole formed on the upper side or the side to receive the external process gas and a plurality of injection holes formed in the direction toward the substrate S to inject the process gas to the substrate S. As an example, the gas injection unit 120 may have a plurality of forms such as a shower head form and a nozzle form. When the gas injection unit 120 is in the shower head form, the gas injection unit 120 is coupled to the process chamber 110 in the form of covering the upper part of the process chamber 110. For example, the gas injection unit 120 is coupled to the side wall portion in the form of a cover of the process chamber 110.

[0072] The substrate placement part 130 is disposed in the process chamber 110 opposite to the gas injection part 120, and the substrate S is placed on the upper part thereof. The substrate placement part 130 may have a structure corresponding to the shape of the substrate. The substrate placement part 130 may include a heater 131 for heating the substrate S. In addition, the substrate placement part 130 may include a heater power supply part for supplying power to the heater 131. Accordingly, the substrate placement part 130 applies power to the heater 131 to heat the substrate. The substrate placement part 130 is connected to an external motor to form a structure that can be raised and lowered, and is called a substrate support, a pedestal, etc.

[0073] The plasma power supply unit 140 may include at least one RF power supply, and in order to form a plasma atmosphere inside the process chamber 110, at least one RF (radio frequency) power is applied to the process chamber 110. For example, the plasma power supply unit 140 may apply RF power to the gas injection unit 120. In this case, the gas injection unit 120 may be referred to as a power supply electrode or an upper electrode. In order to match the impedance between the RF power supply and the process chamber 110, an impedance matching unit 146 is provided between the plasma power supply unit 140 and the gas injection unit 120.

[0074] The RF power supply in the plasma power supply unit 140 may be one or more. As an example, the RF power supply may include multiple RF power supplies with different frequency bands in order to control the plasma environment based on the process conditions. The dual-frequency power supply composed of the first RF power supply 142 and the second RF power supply 144 has the advantage of being able to accurately control the process because the frequency band can be changed according to the process conditions or process steps. In the accompanying drawings, although the power supply of the plasma power supply unit 140 is shown to be two RF power supplies 142 and 144, this is only exemplary and the scope of the present invention is not limited thereto.

[0075] Specifically, the plasma power supply unit 140 includes at least one of a low frequency (LF) power supply in the frequency range of 100kHz to 5MHz, a high frequency (HF) power supply in the frequency range of 5 to 30MHz, and an ultra-high frequency (VHF) power supply in the frequency range of 30 to 80MHz, and can apply low frequency, high frequency, and ultra-high frequency RF power supplies respectively.

[0076] Furthermore, the substrate processing apparatus according to the embodiment of the present invention may include a filter, a current control loop, etc. for impedance adjustment, current control, etc., but is not limited thereto.

[0077] Hereinafter, the present invention is described in more detail based on examples.

[0078] The illustrated embodiments are merely specific examples of the present invention and are not intended to limit the technical structure of the present invention.

[0079] <Example 1>

[0080] The substrate is placed inside the processing space of the process chamber. Titanium tetrachloride gas and ammonia gas are respectively supplied into the processing space. A titanium nitride film is formed on the upper part of the substrate by a thermal CVD process at a temperature of 650°C. Afterwards, a purge step is performed to remove unreacted gas.

[0081] Next, hydrogen (H2) gas was supplied to the upper portion of the titanium nitride film. A low-frequency power supply of 450 kHz was applied at a power of 450 W to form a first plasma. The surface of the titanium nitride film was treated for 10 seconds using hydrogen plasma containing hydrogen ions activated by the first plasma.

[0082] Next, ammonia (NH3) gas and hydrogen (H2) gas were supplied to the upper portion of the titanium nitride film that had completed the first surface treatment. Furthermore, a low-frequency power supply of 450 kHz was applied at a power of 450 W to form a second plasma. The titanium nitride film was subjected to a nitridation treatment for 30 seconds using a nitrogen plasma containing nitrogen ions activated by the second plasma. Thus, a nitrided film with a thickness of 100 mm was formed on the upper portion of the substrate. At this time, the hydrogen plasma treatment and the second plasma treatment are performed once respectively.

[0083] <Example 2>

[0084] A high-frequency power supply of 13.56 MHz was applied at a power of 450 W to form a first plasma, and the titanium nitride film was subjected to surface treatment. Next, a high-frequency power supply of 13.56 MHz was applied at a power of 450 W to form a second plasma, and the titanium nitride film subjected to surface treatment with hydrogen plasma was subjected to nitridation treatment. Except for this, the titanium nitride film was formed by the same method as in Example 1. Accordingly, the thickness of the titanium nitride film formed was

[0085] <Example 3>

[0086] The titanium nitride film was formed by the same method as in Example 1, except that a low-frequency power of 450 kHz and a high-frequency power of 13.56 MHz were applied at a power of 450 W to form a first plasma and a second plasma respectively to perform surface treatment. Thus, the thickness of the titanium nitride film formed was

[0087] <Comparative Example>

[0088] In the same manner as in Example 1, titanium tetrachloride gas and ammonia gas were supplied respectively, and a titanium nitride film was formed on the upper part of the substrate by a thermal CVD process, except that the first plasma and the second plasma were not used for the surface treatment.

[0089] <Experimental example>

[0090] (1) Evaluation of the effects of hydrogen plasma treatment

[0091] In order to evaluate the effect of hydrogen plasma treatment, the chloride ion concentration of the thin films formed by the methods of Examples 1 to 3 was evaluated by secondary ion mass spectrometry (SIMS). The results are as follows: Figure 7 At this time, the film that was not treated with hydrogen plasma was evaluated together as a non-treated control group (control).

[0092] Figure 7As shown, the concentration of chloride ions is reduced by hydrogen plasma treatment, and in particular, the effect of removing residual chloride ions is most prominent when dual plasma is used.

[0093] (2) Evaluation of the influence of surface nitriding treatment 1

[0094] In order to evaluate the effect of surface nitridation on resistance, the thickness of the film formed by the method of the embodiment and the comparative example was evaluated (unit: ), pressure (unit: MPa), average sheet resistance (Rs avg., unit: Ω / □) and sheet resistance uniformity (Rs Unif., unit: %)), the results are shown in Table 1.

[0095]

Table 1

[0096]

[0097] As shown in Table 1, the target thickness is In the process of forming the titanium nitride film, if the methods of the embodiment and the comparative example are adopted, thin films with no large deviation will be formed respectively.

[0098] At the same time, the film pressure was reduced by more than 32% by the surface nitridation treatment compared with the untreated control group, that is, the comparative example, and in particular, it was reduced by more than 48% by the dual plasma treatment.

[0099] Furthermore, the results of confirming the average sheet resistance and sheet resistance uniformity of each thin film showed that the resistance characteristics were greatly improved by the dual-frequency plasma treatment, and the application of HF power also improved the physical properties.

[0100] (3) Evaluation of the influence of surface nitriding treatment 2

[0101] In order to evaluate the effect of plasma nitridation on cracks in the film, the film quality of the film formed by the method of the embodiment and the comparative example was evaluated by electron microscopy. The results are as follows: Figure 8 .

[0102] like Figure 8 (b) Figure 8 (c) and Figure 8 As shown in (d), no cracks appeared when plasma was used. Figure 8 As shown in (a), cracks appeared in the comparative example without plasma treatment. From this result, it can be confirmed that plasma nitridation treatment can prevent cracks from occurring in the thin film.

[0103] The above results show that when the metal nitride thin film forming method of the embodiment is used, even if a thick metal nitride thin film is formed, cracks are less likely to occur, and a metal nitride thin film with low resistance, low residue concentration and excellent electrical characteristics can be formed.

Claims

1. A method for forming a metal nitride thin film, characterized in that: The steps include: preparing a substrate in a process chamber forming a processing space; supplying a metal precursor gas and a nitrogen-containing gas respectively to form a metal nitride film on an upper portion of the substrate; Supplying a hydrogen-containing gas into the process chamber to form a first plasma and perform at least one first surface treatment on the metal nitride film; and A nitrogen-containing gas is supplied to the process chamber to form a second plasma, and at least one second surface treatment is performed on the substrate that has undergone the first surface treatment.

2. The method for forming a metal nitride thin film according to claim 1, wherein: In the step of forming the thin film, The metal nitride thin film is formed by reacting the metal precursor gas with the nitrogen-containing gas through a thermal chemical vapor deposition method performed at a temperature of 300 to 800° C.

3. The method for forming a metal nitride thin film according to claim 1, wherein: The metal nitride film includes one of titanium nitride (TiN), tungsten nitride (WN), molybdenum nitride (Mo2N), tantalum nitride (TaN), aluminum nitride (AlN) and titanium aluminum nitride (TiAlN).

4. The method for forming a metal nitride thin film according to claim 1, wherein: The metal precursor gas includes a metal precursor including at least one of titanium tetrachloride (TiCl4), tetrakis(dimethylamino)titanium (TDMAT, Ti(N(Me2)4)), tetrakis(diethylamino)titanium (TDEAT, Ti(N(Et2)4)) and tetrakis(ethylmethylamino)titanium (TEMAT, Ti(N(EtMe)4)).

5. The method for forming a metal nitride thin film according to claim 1, wherein: The nitrogen-containing gas includes at least one of ammonia (NH 3 ) and nitrogen (N 2 ).

6. The method for forming a metal nitride thin film according to claim 1, wherein: In the first surface treatment step, a dual-frequency power source is applied to form the first plasma.

7. The method for forming a metal nitride thin film according to claim 6, wherein: At least one of a high frequency or an ultra-high frequency and a low frequency are applied to form the first plasma.

8. The method for forming a metal nitride thin film according to claim 1, wherein: In the second surface treatment step, a dual-frequency power source is applied to form the second plasma.

9. The method for forming a metal nitride thin film according to claim 8, characterized in that: The second plasma is formed by applying a low frequency and at least one of a high frequency or an ultra-high frequency.

10. The method for forming a metal nitride thin film according to claim 1, wherein: In the second surface treatment step, a hydrogen-containing gas is also supplied.

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