Thin film deposition methods

Abstract

The present invention relates to a thin film deposition method, and more specifically, to a thin film deposition method that can prevent the increase in thickness of ultrafine thin films and changes in physical properties caused by generated particles by introducing a pulsed plasma purging process. The thin film deposition method of the present invention applies RF power to a chamber and utilizes a substrate processing apparatus that generates plasma within the chamber to form a thin film on a substrate. The method includes: preparing a substrate within the chamber; generating a first plasma within the chamber, supplying source gas, and forming a thin film layer on the substrate; and generating a second plasma with a preset duty cycle within the chamber, supplying an inert gas, and purging the chamber to remove any residual source gas.

Description

Technical Field

[0001] The present invention relates to a thin film deposition method, and in particular to a thin film deposition method which prevents the thickness of ultra-fine thin films from increasing and physical property changes caused by granulation by introducing a pulsed plasma purge process. Background Art

[0002] With the increasing integration of electronic components, thin-film manufacturing processes are being actively developed to utilize EUV to produce ultra-thin films measuring several angstroms or even tens of angstroms. In particular, plasma-enhanced chemical vapor deposition (PECVD) generates plasma in a reaction chamber, depositing thin films through chemical reactions of source gases. PECVD utilizes the plasma to energize the source gases, enabling deposition at low temperatures, a feature that has been widely utilized.

[0003] More specifically, the PECVD method applies high pressure to a chamber, generating plasma within the chamber. Furthermore, after the source gas is injected, the source gas becomes ionized, or plasma, due to the plasma already generated within the chamber. When the wafer mounted within the chamber is heated to a predetermined temperature, a chemical reaction occurs between the material to be deposited and the surface of the object. This chemical reaction causes the deposited material to bond to the surface of the object, effectively eliminating all other materials except the deposited material.

[0004] However, when depositing thin films using PECVD, source gases may remain in the chamber without reacting. This residual source gas can then form particles through other chemical reactions. Therefore, to eliminate generated particles, continuous wave plasma (CW plasma) can be applied for a short period of time in a low-power region along with an inert gas to control particle formation.

[0005] In addition, in the above-mentioned existing process, the residual gas reacts with the film under the action of plasma, resulting in an increase in the film thickness. The emergence of this problem makes it difficult to manufacture ultra-fine films at the level of several angstroms or even tens of angstroms.

[0006] Furthermore, after a thin film is formed on a wafer, particles can adhere to the wafer surface during the purge phase to remove residual source gas, potentially degrading the physical properties of semiconductor devices. Therefore, further research is needed to address this issue. Thin film deposition methods must not only prevent variations in film thickness but also prevent particles from adhering to the film surface, thereby preventing degradation of physical properties. Summary of the Invention

[0007] Technical issues

[0008] According to an embodiment of the present invention, a thin film deposition method is provided, which can prevent the generation of residual non-reactive source gas, thereby preventing the increase in thickness of the thin film and the occurrence of granulation phenomena that lead to changes in physical properties.

[0009] Means of solving the problem

[0010] A thin film deposition method can apply RF power to a chamber and utilize a substrate processing device that generates plasma inside the above chamber to form a thin film on a substrate. The method includes: a step of preparing a substrate inside the above chamber; a thin film formation step of generating a first plasma inside the above chamber and supplying a source gas to form a thin film layer on the above substrate; and a pulsed plasma purging step of generating a second plasma with a preset duty cycle into the above chamber and supplying an inert gas to remove residual source gas inside the above chamber.

[0011] According to one embodiment, the thin film layer is a carbon hard film layer.

[0012] According to one embodiment, in the thin film forming step, 50 to 150 W of RF power may be applied to form the first plasma, and in the pulsed plasma purge step, 0 to 50 W of RF power may be applied to generate the second plasma.

[0013] According to one embodiment, the first plasma is a pulsed plasma having a duty cycle different from that of the second plasma.

[0014] According to one embodiment, the duty ratio of the second plasma is between 5% and 50%.

[0015] According to one embodiment, the first plasma may be a pulsed plasma formed by supplying a power supply of 2000 to 10000 Hz; and the second plasma may be a pulsed plasma formed by supplying a power supply of 10 to 2000 Hz.

[0016] According to one embodiment, the above-mentioned substrate processing device includes: a chamber, which provides a substrate processing space; a power supply unit, which applies at least one RF power supply to generate continuous wave plasma or pulsed plasma into the inside of the above-mentioned chamber; a gas supply unit, which supplies source gas for forming a thin film layer into the inside of the above-mentioned substrate processing space; and a control unit, which controls the driving of the above-mentioned power supply unit and the above-mentioned gas supply unit.

[0017] Effects of the Invention

[0018] According to the thin film deposition method of the embodiment, a pulsed plasma purge process is introduced to maintain the film thickness and film contact angle unchanged while clearing unreacted source gas and particles inside the chamber, thereby successfully forming an ultrafine film. BRIEF DESCRIPTION OF THE DRAWINGS

[0019] Figure 1 1 is a reference diagram for explaining power modulation of continuous wave plasma and pulsed plasma in the thin film deposition method of the embodiment.

[0020] Figure 2 (a) and (b) are timing diagrams illustrating a thin film deposition method according to various embodiments.

[0021] Figure 3 A conceptual diagram schematically shows an example of a substrate processing apparatus used in a thin film deposition method according to an embodiment.

[0022] Figure 4 These are the results of analyzing the contact angles of thin films formed on the various processed samples based on the methods of Reference Example, Comparative Example, and Example.

[0023] Figure 5 These are the results of analyzing the thickness of thin films formed in the respective processed samples based on the methods of the reference example, the comparative example, and the embodiment.

[0024] (Explanation of Reference Numerals)

[0025] 10: Substrate processing equipment

[0026] 100: Chamber 200: Power supply unit

[0027] 300: Air supply unit 400: Control unit DETAILED DESCRIPTION

[0028] The embodiments of the present invention will be described in detail below with reference to the accompanying drawings so that those skilled in the art in the art to which the present invention belongs can easily understand and implement them. However, the description of the present invention is only an embodiment of the structure and even the function description, so it cannot be considered that the scope of the rights of the present invention is limited to the embodiments described herein. That is, the embodiments can be modified in various ways and can be adjusted into various forms. Therefore, the scope of the rights of the present invention should be understood to include equivalent inventions that can realize the technical ideas. In addition, the purpose or effect of the present invention does not mean that a specific embodiment must include all or only partially include these effects, so the scope of the claims of the present invention cannot be limited accordingly.

[0029] The technical terms used in the present invention have the following meanings.

[0030] The terms "first" and "second" are used only to distinguish one component from other components, but the scope of the claims cannot be limited by the above terms. For example, without departing from the claims of the present invention, the first structural element can be named the second structural element. Similarly, the second structural element can also be named the first structural element. When a structural element is mentioned as being "connected" or "in contact" with other structural elements, it can be directly connected to the other structural elements or directly in contact, but it should be understood that other structural elements may exist in between. Conversely, when a structural element is mentioned as being "directly connected" or "directly in contact" with other structural elements, it should be understood that there are no other structural elements in between. In addition, different words that describe the relationship between various structural elements, such as "between" and "just between" or "adjacent to" and "directly adjacent to", should be understood to express similar meanings.

[0031] For singular expressions, plural expressions may also be included unless otherwise specified or indicated in the preceding or following context. In the present invention, terms such as "including" or "having" should be understood as indicating the presence of the specified features, numbers, stages, actions, structural elements, components, or combinations of these components in the specification, without excluding the possibility of the presence or addition of one or more other features, numbers, stages, actions, structural elements, components, or combinations of these components.

[0032] Unless otherwise defined, all terms used herein, including technical or scientific terms, have the same meaning as those understood by one of ordinary skill in the art to which this invention belongs. Similar terms defined in commonly used dictionaries should be interpreted to have the same meaning as those used in the context of the relevant art. Therefore, unless otherwise clearly defined in this application, they should not be interpreted in an excessively transcendental or formal sense.

[0033] Many existing processes typically use a method of controlling particle generation by supplying an inert gas and applying electricity during the diffusion step. However, this can cause a reaction with residual source gas supplied during the deposition process, leading to increased thickness.

[0034] While most materials vary, silicon carbide (SiC) in particular has been shown to exhibit a 4% increase in thickness even with a low power supply of 30W during the diffusion step. In processes requiring ultrathin films of several to tens of angstroms, a 4% increase in thickness due to plasma diffusion results in significant variations in overall process thickness, necessitating appropriate control.

[0035] Furthermore, even on the surface, the inert gas is subjected to physical impact. This causes a change in the surface contact angle, which in turn reduces the bonding strength with other materials. The adhesion between the carbon hardcoat layer and the photoresist is particularly important, and the most important factor determining this adhesion is the contact angle. Changes in the contact angle caused by plasma purging can affect the bonding with the photoresist, potentially causing defects in the pattern.

[0036] The inventors of the present invention have determined that, in the existing plasma purge step, if pulsed plasma purge is performed using the plasma oscillation frequency and duty cycle, a higher potential difference can be achieved compared to the prior art, resulting in a lower electron density and temperature in the plasma off period. Furthermore, the reaction energy is reduced, preventing reaction with residual gases. This prevents thickness increase, thereby controlling particles and further preventing contact angle changes caused by the physical treatment effects of the inert gas. This completes the thin film deposition method according to the embodiment.

[0037] Hereinafter, the semiconductor manufacturing method in the embodiment will be described in detail.

[0038] According to an embodiment of the semiconductor manufacturing method, as a thin film deposition method of a substrate processing device that generates plasma inside a chamber and forms a thin film on a substrate, it includes: a step of preparing a substrate inside a chamber; a thin film forming step of supplying a source gas after generating a first plasma inside the chamber to form a thin film layer on the above-mentioned substrate; and a pulsed plasma blowing step of supplying an inert gas after generating a second plasma with a preset duty cycle inside the chamber to clear the residual source gas inside the above-mentioned chamber.

[0039] First, the substrate preparation step is a step of preparing a substrate inside a chamber.

[0040] The substrate can be manufactured using various materials known in the field of semiconductor device manufacturing. The substrate can be a finished semiconductor substrate with a predetermined device formed thereon, or it can be a bare wafer.

[0041] Specifically, the substrate can include crystalline silicon, silicon oxide, silicate nitride, silicon nitride, strained-silicon, silicon germanium, tungsten, titanium nitride, doped or undoped polysilicon, doped or undoped silicon wafer, unpatterned or patterned wafer, silicon on insulator (SOI), carbon-doped silicon oxide, doped silicon, germanium, gallium, arsenic, low-K dielectric, or be made of a material containing any of the above substances.

[0042] Alternatively, the substrate may be formed with an etching layer, and the etching layer may be composed of a silicon oxide film, a silicon nitride film, a silicon oxide film, a silicon carbide (SiC) film, or an inductor film thereof.

[0043] Next, in the thin film forming step, a first plasma is generated inside the chamber and a source gas is supplied, thereby forming a thin film layer on the substrate.

[0044] In this step, a PECVD (plasma enhanced chemical vapor deposition) method can be used to simultaneously supply a source gas and an inert gas to deposit a thin film layer. The inert gas can be at least one selected from helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). In particular, the inert gas can include argon (Ar).

[0045] The source gases can be selected based on the desired film type. Specifically, the film layer can be a hardcoat layer. To form such a hardcoat layer, a variety of source gases can be used under normal conditions to form the film layer. The source gases can be any of alkylsilanes such as trimethylsilane (3MS) and tetramethylsilane (4MS), hydrocarbons such as ethylene, siloxane (SiON), and silazane (Si3N4).

[0046] In particular, the thin film layer can be formed into a silane carbon hardcoat layer using a silane hydrocarbon such as trimethylsilane (3MS) or tetramethylsilane (4MS). This carbon hardcoat layer does not change in contact angle during or after treatment with the pulsed plasma purging step described below, thereby preventing a decrease in bonding strength and enabling the successful realization of a semiconductor device with superior characteristics.

[0047] For example, in the thin film deposition method according to the embodiment, the first plasma may be continuous wave plasma. In this step, continuous wave plasma is generated as the first plasma in the chamber to form a thin film, thereby supplying a raw gas and forming a thin film layer.

[0048] Furthermore, the first plasma may be a pulsed plasma. To form a thin film, a pulsed plasma may be generated within the chamber and a source gas may be supplied to form the thin film layer. Furthermore, the first plasma may have a different duty cycle than the second plasma. Details regarding the pulsed plasma used in the thin film formation step are described below.

[0049] The thickness of the thin film layer can be 5 to 100 Å. As mentioned above, when the thickness of a very thin ultrafine film varies by 1 to 10 Å, it can significantly affect physical properties. Therefore, if the thin film deposition method described in the embodiment is used, the thickness variation will not occur, making the method easier to apply. In particular, the thickness of the thin film layer can be 5 to 30 Å.

[0050] On the other hand, the pulsed plasma purging step is a step of generating a second plasma with a preset duty cycle in the chamber after forming a thin film layer on the substrate, supplying an inert gas, and then clearing the residual source gas in the chamber.

[0051] In this step, a purge process may be performed by supplying an inert gas. The inert gas may be selected from at least one of helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and radon (Rn). In particular, the inert gas may include argon (Ar) gas.

[0052] In this step, a simple method of turning on / off the plasma power supply can be used to form a second plasma with a preset duty ratio. The second plasma can adjust the processing efficiency of the purge process through pulse frequency, duty ratio, and power modulation.

[0053] Specifically, the pulse frequency refers to a ratio at which pulse power is repeatedly pulsed at regular time intervals.

[0054] The duty ratio, or pulse operation ratio, refers to the ratio of the on-time to the off-time of a pulsed plasma. For example, a 30% duty ratio means that, for a pulse cycle of 100%, the on-time of the pulsed plasma is 30% and the off-time is 70%. Because this duty ratio can be adjusted as the ratio of on-time to off-time, the degree of charge cancellation and reactivity can be adjusted based on the degree of change.

[0055] like Figure 1As shown in the figure, the above power modulation can be roughly divided into the following four types: continuous wave plasma (CW) in which the plasma source is continuously applied; a bias pulse method (bias pulse) in which pulses are applied to the substrate while the plasma source is maintained with a continuous wave; a source pulse method (source pulse) in which pulses are applied to the plasma source while the substrate electrode is maintained with a continuous wave (CW); and a synchronous pulse method (synchrons pulse) in which pulses are applied to both the plasma and the substrate (regardless of whether there is a phase difference).

[0056] More specifically, in the thin film deposition method according to the embodiment, the thin film forming step and the pulsed plasma purging step can be respectively performed by adjusting the pulse frequency, duty ratio, and power modulation.

[0057] First, in the thin film formation step, the charge density is increased to speed up the deposition rate. In the purge step, the RF power supply and duty cycle can be adjusted to varying degrees according to the needs of each step, thereby reducing the charge density and making the control of residual gas more efficient.

[0058] For example, during the thin film formation step, an RF power supply of 50 to 500 watts can be applied to operate. Furthermore, during the pulsed plasma purge step, an RF power supply of 10 to 50 watts can be applied to generate regular and uniform pulses, thereby generating a second plasma with a lower density than the first plasma. This RF power supply can generate high-frequency (HF) power plasma.

[0059] Furthermore, in the thin film forming step and the pulsed plasma purging step, a high-frequency power supply of 10 to 1×10⁶ Hz can be supplied to generate pulsed plasmas, or pulsed plasmas of different frequencies can be generated. In particular, the first plasma can be a pulsed plasma of 2000 to 10,000 Hz, and the second plasma can be a pulsed plasma of 10 to 2000 Hz.

[0060] Furthermore, during the pulsed plasma purge step, a duty cycle of 5% to 50% can be used to generate a pulsed plasma. The lower the duty cycle, the longer the off time, and the higher the particle control efficiency. However, if the off time is too long, the efficiency decreases, so this can be adjusted appropriately. In particular, a duty cycle of 5% to 15% can be used to generate a pulsed plasma during the pulsed plasma purge step.

[0061] Furthermore, in the thin film forming step, the first plasma can be formed with the same or different duty cycle as in the pulsed plasma purging step. In particular, the first and second plasmas can be formed with the same duty cycle to simplify the process.

[0062] Moreover, in the thin film deposition method according to the embodiment, in the purge step, a source pulse method (source pulse) is used to generate a pulse on / off potential difference, thereby clearing the particles. This is because the second plasma is a pulsed plasma, and compared with the continuous wave plasma, the temperature of the electrons in the pulsed plasma Off interval is getting lower and lower. The reactivity with the unreacted residual source gas is reduced, and the thickness will not increase. In addition, in the Off interval, due to the low potential and low temperature, the electron density is reduced, so that the surface of the thin film layer will not be damaged, so no notching or bowing will occur, and even the contact angle will not change.

[0063] Therefore, in the thin film deposition method of the embodiment, as Figure 2 As shown in (a). During the thin film forming step t1, source gas and inert gas are supplied, and a first plasma is formed in the chamber to form a thin film layer. Then, during the purge step t2, inert gas is supplied, a second plasma is formed in the chamber, and a purge process is performed.

[0064] In particular, in the thin film deposition method of the embodiment, as Figure 2 (b) In the thin film formation step t1, source gas and inert gas are supplied to form a first plasma in the chamber to form a thin film layer. Then, in the diffusion step t2, inert gas is supplied to form a second plasma in the chamber to perform the diffusion process. The first plasma has a higher frequency than the second plasma.

[0065] In addition, in the thin film deposition method of the embodiment, after performing the pulsed plasma purging step, a gas purging step may be further included.

[0066] The gas purge step may be performed by supplying a purge gas. While the generation of the pulsed plasma is stopped, the purge gas is supplied to the chamber, and particles and unreacted source gas are removed by the strong flow of the purge gas. The gas purge step may include a pumping process for removing gas from the chamber.

[0067] In addition, in the thin film deposition method of the embodiment, a substrate processing apparatus may be used to apply at least one RF power source to a chamber and generate plasma inside the chamber to form a thin film on a substrate.

[0068] If the substrate processing apparatus 10 is described in detail, the substrate processing apparatus 10 may include: a chamber 100 providing a substrate processing space; a power supply unit 200 applying at least one RF power source and generating a continuous wave plasma or a pulsed plasma inside the above-mentioned chamber 100; a gas supply unit 300 supplying a substrate processing source gas into the above-mentioned substrate processing space; and a control unit 400 controlling the driving of the above-mentioned power supply unit 200 and the above-mentioned gas supply unit 300.

[0069] Specifically, the chamber 100 provides an environment that enables a substrate W to be maintained within the chamber while a thin film layer made of a material on the substrate W is formed using a plasma CVD method. The chamber 100 may include a main body 110 with an open top and a cover 120 that seals the upper portion of the main body. The interior of the chamber 100 may be a space for performing deposition processes and other treatments on the substrate W. A passage door G for carrying substrates W in and out may be provided at a designated location on the side of the main body 110. A through hole may be formed at the bottom of the main body for inserting a support shaft of a substrate base 130.

[0070] The susceptor 130 is generally flat, with at least one substrate W positioned on its upper surface. It is mounted horizontally, opposite the gas supply unit 300. A support shaft 140 is vertically coupled to the rear surface of the susceptor 130 and connects to an external drive unit (not shown) via a through-hole in the bottom of the chamber 100, thereby enabling the susceptor 130 to be raised, lowered, and / or rotated. In one embodiment, the susceptor 130 can function as a second electrode.

[0071] The base 130 is provided with a heater H inside to adjust the temperature of the substrate placed on the top. The heater H is connected to a power supply unit 150 that supplies power to one side, so that the heater can generate heat.

[0072] A vacuum environment is typically required within the chamber 100, so an exhaust port may be provided at a designated location within the chamber, such as the bottom. The exhaust port may be connected to an external pump 160. The exhaust port maintains a vacuum within the chamber and allows gases to be exhausted after the process is complete.

[0073] In order to form a thin film layer and perform a purge step in the thin film formation step, the power supply unit 200 can supply power with a preset frequency band through a plasma power source. The power supply unit 200 can form a continuous wave plasma and can form a pulsed plasma by adjusting the power on / off. To this end, the power supply unit 200 may include a plurality of power application components that can apply RF power of different frequencies and can perform extended modulation. The above-mentioned power process components can provide RF power for bias application, and can also provide RF power for applying plasma to the plasma source. In addition, an RF power supply for applying pulses to the plasma and the substrate can also be provided.

[0074] The gas supply unit 300 includes a gas supply device mounted on the upper portion of the main body and facing the base 130. The gas supply unit 300 includes at least one gas storage tank 310, which sprays various process gases into the chamber 100. The gas supply unit can be selected from a variety of gas supply types, including showerhead, syringe, and nozzle. The gas supply device in the gas supply unit 300 can serve as the first electrode.

[0075] The gas supply unit 300 includes a gas tank 310 , a valve V, and a gas supply line L. The gas tank 310 can store source gas and inert gas, respectively, and can supply various gases to the chamber 100 through the gas supply line L.

[0076] The valve V is installed between the gas storage tank 310 and the gas supply line L, is used to adjust the various gases supplied to the chamber 100, and is installed on each gas supply line L.

[0077] The control unit 400 controls the on / off state of the RF power supplied by the power supply unit 200 according to pre-set control parameters, ensuring that the RF power has a predetermined duty ratio and a predetermined frequency. The frequency of the RF power can be understood as the number of times the RF power is turned on and off within a specified time period, while the duty ratio is the ratio of the RF power's on / off state during the time the RF power is applied.

[0078] The substrate processing apparatus 10 having the above-described structure can generate continuous wave plasma and pulsed plasma in the chamber 100 to drive and perform a thin film deposition step and a purge step.

[0079] Furthermore, existing technologies use continuous wave plasma (CWP) to perform the purge process. However, this process suffers from the problem of plasma purge reacting with residual reactant gases, which can increase film thickness by several orders of magnitude. This is particularly true in carbon hard film processes, where the target film thickness is less than 10 Å. In such thin films, this increase in film thickness can significantly impact linewidth (critical dimension, CD) deviation.

[0080] To prevent this, the present invention proposes a plasma purging process using pulsed plasma. When using this pulsed plasma to purge the diffusion, a high potential difference can be achieved, and low electron density and low electron temperature can be achieved in the plasma off range.

[0081] In addition, compared with the prior art, the high potential difference can effectively control particles in a short time, and the low electron density and electron temperature can prevent the thickness of the thin film layer from increasing by preventing additional reactions with unreacted source gases during the deposition process.

[0082] Furthermore, the repair effect caused by the inert gas due to the low electron density can be prevented, thereby preventing the change of the contact angle of the thin film layer.

[0083] According to a preferred embodiment of the present invention, in the thin film forming step, a 100W RF power is applied, the duty ratio can reach 70%, and a 50kHz frequency RF power is applied to generate a pulsed plasma in the chamber, and a mixed gas including a source gas of trimethylsilane and an argon gas is provided, thereby forming a thin film with a thickness of 5 to 100W. In addition, during the pulsed plasma purge step, a 30W RF power supply is applied, resulting in a 10% duty cycle. A 50Hz RF power supply is applied to generate a pulsed plasma within the chamber, and the purge process is performed after supplying inert gases including argon.

[0084] Hereinafter, embodiments of the present invention will be described in more detail.

[0085] The presented embodiment is merely a specific example of the present invention, and the technical scope of the present invention is not limited to the embodiment.

[0086] <Example>

[0087] The substrate, with the etched layer formed on it, was placed in the chamber of a PECVD apparatus. Source gases including trimethylsilane and argon were supplied, followed by the application of 100W RF power with a 10% duty cycle. The RF power was applied at a frequency of 500,000 Hz, generating a pulsed plasma within the chamber while forming a carbon hard film layer on the substrate.

[0088] An inert gas was supplied to the substrate with the carbon hard film layer formed. A 30W RF power supply with a 10% duty cycle and a 50Hz RF power supply were simultaneously applied to generate a pulsed plasma within the chamber to perform a purge process. Following the pulsed plasma, a purge gas was supplied. After an additional pumping purge process, the gas was discharged into the chamber by pumping. This method uses pulsed plasma to perform a purge process to produce substrate samples (pursed plasma purge).

[0089] <Comparative Example>

[0090] The substrate samples were fabricated using the same method as in the embodiment except that the purge process was performed using continuous wave plasma (CW plasma purge).

[0091] <Reference example>

[0092] The substrate sample was processed and manufactured using the same method as in the embodiment, except that only the gas purge process was performed (No plasma purge).

[0093] <Experimental Example>

[0094] (1) Analysis of impact on surface

[0095] The surface changes of the manufactured substrate samples were confirmed, and the results were as follows Figure 2 Surface changes are confirmed by measuring contact angles.

[0096] like Figure 2 As shown in the data, the contact angle of the substrate sample of the reference example was 91.4°, while the contact angle of the substrate sample treated using the method of the embodiment was 89.6°, confirming that the contact angle had slightly changed. In contrast, the contact angle of the substrate sample treated using the method of the comparative example was 79.8°, confirming that the contact angle had significantly changed. In particular, the contact angle measurement resolution is approximately 3°. Therefore, considering that the difference in contact angle between the embodiment and the reference example is within 3°, the predicted contact angle actually barely changed.

[0097] The above results indicate that continuous plasma treatment may change the surface of the film, thereby reducing the bonding strength with the photoresist. In contrast, when pulsed plasma is introduced, the contact angle changes very little, so the bonding strength does not decrease.

[0098] (2) Analysis of the impact on film thickness

[0099] The thickness variation of the manufactured substrate samples was confirmed by experiments, and the relevant results are shown in Table 1 below.

[0100] thickness Allowable error Example 12.5 1.8 Comparative Example 16.4 1.8 Reference Example 12.4 1.8

[0101] As shown in Table 1, it can be confirmed that: compared with the reference example, the substrate sample processed by the method of the embodiment has almost no thickness change; on the contrary, after the continuous plasma purge process, the residual gas reacts and the thickness of the substrate sample of the comparative example increases by about 4%.

[0102] From the above results, it can be seen that when the thickness of the film is a certain value, the residual raw material gas reacts under the action of the continuously supplied plasma. After introducing the pulsed plasma purge process, the influence of CD deviation can be reduced. Therefore, this method is the most preferred method.

[0103] (3) Analysis of the impact on particle generation

[0104] In addition, a general purge process (5 times in total, #1 to #5) and a pulsed plasma purge process (5 times in total, #6 to #10) were performed to confirm whether large particles exceeding 0.042 to 42 nm in size were formed. The relevant results are summarized in Table 2 below.

[0105]

Table 2

[0106]

[0107] As shown in Table 2, the reference example experiment confirmed that an average of 3.1 particles were generated during the purge process. In contrast, an average of 0.6 particles were generated during the pulsed plasma purge process. These results demonstrate that the pulsed plasma purge process prevents the generation of large particles, thus preventing degradation of semiconductor device properties.

[0108] The above description is based on the preferred embodiments of the present invention and provides a detailed description of the present invention. However, the present invention is not limited to the above embodiments. Within the scope of the technical concept of the present invention, those skilled in the art with general knowledge in the art can make corresponding modifications based on the above embodiments.

Claims

1. A thin film deposition method, comprising applying RF power to a chamber and utilizing a substrate processing apparatus that generates plasma within the chamber to form a thin film on a substrate, wherein: include: a step of preparing a substrate into the chamber; A thin film forming step of generating a first plasma in the chamber and supplying a source gas to form a thin film layer on the substrate; and a pulsed plasma purge step of generating a second plasma having a lower duty cycle than the first plasma into the chamber and supplying an inert gas to remove residual source gas in the chamber; The second plasma is a low-density plasma having a lower density than that of the first plasma.

2. The thin film deposition method according to claim 1, wherein: The thin film layer is a carbon hard film layer.

3. The thin film deposition method according to claim 1, wherein: In the above-mentioned thin film forming step, RF power of 50 to 150 W is applied.

4. The thin film deposition method according to claim 1, wherein: The first plasma is a pulsed plasma.

5. The thin film deposition method according to claim 1, wherein: In the pulsed plasma purging step, 10 to 50 W of RF power is applied.

6. The thin film deposition method according to claim 1, wherein: The second plasma has a duty cycle between 5% and 50%.

7. The thin film deposition method according to claim 1, wherein: The first plasma is a pulsed plasma formed by supplying a power supply of 2000 to 10000 Hz.

8. The thin film deposition method according to claim 1, wherein: The second plasma is a pulsed plasma formed by supplying power at 10 to 2000 Hz.

9. The thin film deposition method according to claim 1, wherein: The substrate processing device comprises: The chamber provides a substrate processing space; a power supply unit for applying at least one RF power source to generate continuous wave plasma or pulsed plasma into the chamber; a gas supply portion for supplying source gas for forming a thin film layer into the substrate processing space; and The control unit controls the driving of the power supply unit and the air supply unit.

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