Substrate processing method

Abstract

A substrate processing method according to an aspect of the present invention relates to a substrate processing method using a substrate processing apparatus including a process chamber, a substrate support unit including an electrostatic electrode therein, and a gas injection unit. The substrate processing method comprises the steps of: applying a first voltage of a first polarity to the electrostatic electrode; forming a first thin film on a substrate in a state in which the first voltage is applied to the electrostatic electrode; applying a second voltage of a second polarity opposite to the first polarity to the electrostatic electrode; and forming a second thin film on the substrate in a state in which the second voltage is applied to the electrostatic electrode.

Description

Substrate processing method

[0001] The present invention relates to semiconductor manufacturing, and more specifically, to a substrate processing device and substrate processing method using plasma.

[0002] To manufacture semiconductor devices, various substrate processing processes are performed in a vacuum-based substrate processing device. For example, a substrate may be loaded into a process chamber, and processes such as depositing a thin film or etching the thin film may be performed. The substrate is mounted on a substrate support installed within the process chamber and can be chucked to the substrate support using electrostatic force.

[0003] Recently, as the thickness of thin films formed on substrates increases or the height of alternately stacked thin films increases, thickness non-uniformity in these films has become a growing issue. As the height of single or stacked thin films increases, a consistent color pattern is formed on the thin films, resulting in thickness non-uniformity. Furthermore, attempts to reduce thickness non-uniformity have resulted in increased particle formation in the thin films.

[0004] The present invention aims to address various issues, including those described above, by providing a substrate processing method capable of enhancing process stability by suppressing particle generation and reducing thickness unevenness that occurs as the height of a single or laminated thin film increases. However, these tasks are exemplary and are not intended to limit the scope of the present invention.

[0005] According to one aspect of the present invention for solving the above problem, a substrate processing method is provided, which comprises a substrate processing apparatus including a process chamber having a reaction space formed therein, a substrate supporter coupled to the process chamber to support a substrate and including an electrostatic electrode therein, and a gas injection unit installed in the process chamber to supply a process gas to the reaction space, the substrate processing method comprising the steps of: applying a first voltage of a first polarity to the electrostatic electrode; in a state where the first voltage is applied to the electrostatic electrode, injecting a process gas into the reaction space through the gas injection unit while forming a plasma atmosphere in the reaction space, thereby forming a first thin film on the substrate; applying a second voltage of a second polarity opposite to the first polarity to the electrostatic electrode; in a state where the second voltage is applied to the electrostatic electrode, injecting a process gas into the reaction space through the gas injection unit while forming a plasma atmosphere in the reaction space, thereby forming a second thin film on the substrate.

[0006] In the above substrate processing method, the method may include a step of sequentially repeating the steps of applying the first voltage, forming the first thin film, applying the second voltage, and forming the second thin film multiple times.

[0007] In the above substrate processing method, the first thin film and the second thin film may include the same insulating material.

[0008] In the above substrate processing method, after the step of forming the first thin film and before the step of applying the second voltage, the method may include a step of forming a third thin film on the substrate by injecting a process gas into the reaction space through the gas injection unit while forming a plasma atmosphere in the reaction space in a state where the first voltage is applied to the electrostatic electrode, and after the step of forming the second thin film, the method may include a step of forming a fourth thin film on the substrate by injecting a process gas into the reaction space through the gas injection unit while forming a plasma atmosphere in the reaction space in a state where the second voltage is applied to the electrostatic electrode.

[0009] In the above substrate processing method, the step of applying the first voltage, the step of forming the first thin film, the step of forming the third thin film, the step of applying the second voltage, the step of forming the second thin film, and the step of forming the fourth thin film may be sequentially repeated multiple times.

[0010] In the above substrate processing method, in the step of repeating multiple times, the absolute values ​​of the first voltage and the second voltage may gradually increase with each repetition.

[0011] In the above substrate processing method, before the step of applying the second voltage, the step of forming the first thin film and the step of forming the third thin film can be alternately performed multiple times.

[0012] In the above substrate processing method, after the step of applying the second voltage, the step of forming the second thin film and the step of forming the fourth thin film can be alternately performed multiple times.

[0013] In the above substrate processing method, the first thin film, the third thin film, the second thin film, and the fourth thin film have a laminated structure, and the first thin film and the second thin film may include the same first insulator, and the third thin film and the fourth thin film may include the same second insulator.

[0014] In the above substrate processing method, the stacked structure of the first thin film, the third thin film, the second thin film, and the fourth thin film may include an alternating stacked structure of oxide film / nitride film / oxide film / nitride film or an alternating stacked structure of nitride film / oxide film / nitride film / oxide film.

[0015] According to the substrate processing method according to some embodiments of the present invention, which is achieved as described above, the polarity of the voltage applied to the electrostatic electrode during thin film deposition can be toggled to increase the thickness uniformity of the thin film while suppressing particle generation, thereby enhancing process stability. Of course, the scope of the present invention is not limited by these effects.

[0016] FIG. 1 is a schematic cross-sectional view showing a substrate processing device according to one embodiment of the present invention.

[0017] Fig. 2 is a schematic partial cross-sectional view of a substrate support portion of the substrate processing device of Fig. 1.

[0018] Figure 3 is a flowchart showing a substrate processing method according to one embodiment of the present invention.

[0019] Fig. 4 is a graph showing the voltage applied to the electrostatic electrode according to the process step in the substrate processing method of Fig. 3.

[0020] Figure 5 is a flowchart showing a substrate processing method according to another embodiment of the present invention.

[0021] Fig. 6 is a graph showing the voltage applied to the electrostatic electrode according to the process step in the substrate processing method of Fig. 5.

[0022] Figure 7 is a flowchart showing a substrate processing method according to another embodiment of the present invention.

[0023] Figures 8, 9 and 10 are graphs showing the thickness uniformity of thin films formed according to the substrate processing method according to Comparative Example 1, Comparative Example 2 and the embodiment.

[0024] Figure 11 is a graph showing the number of particles on substrates formed according to the substrate processing method according to Comparative Example 1, Comparative Example 2, and the embodiment.

[0025] Hereinafter, various preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0026] The embodiments of the present invention are provided to more fully explain the present invention to those skilled in the art. The following embodiments may be modified in various ways, and the scope of the present invention is not limited to the following embodiments. Rather, these embodiments are provided to more faithfully and completely explain the present disclosure and to fully convey the spirit of the present invention to those skilled in the art. In addition, the thickness and size of each layer in the drawings are exaggerated for convenience and clarity of explanation.

[0027] FIG. 1 is a schematic drawing showing a substrate processing device (100) according to one embodiment of the present invention, and FIG. 2 is a schematic partial cross-sectional view of a substrate support part of the substrate processing device (100) of FIG. 1.

[0028] Referring to FIG. 1, the substrate processing device (100) may include a process chamber (110), a gas injection unit (120), and a substrate support unit (130).

[0029] More specifically, a reaction space (112) in which a substrate (S) can be processed can be formed in the process chamber (110). The process chamber (110) can be connected to a vacuum pump (not shown) through an exhaust pipe (114) so ​​as to form a vacuum atmosphere. A throttle valve (117) for controlling the opening rate of the exhaust pipe (114) can be installed. The throttle valve (117) can be used to control the pressure of the reaction space (112) within the process chamber (110).

[0030] Furthermore, the process chamber (110) may be provided with an entrance for loading a substrate (S) into or unloading the substrate (S) from the reaction space (112) and a gate structure (not shown) for opening and closing the entrance. The process chamber (110) may be provided in various shapes, and may include, for example, a body portion (1102) and a top lid (1104). For example, the body portion (1102) may define the reaction space (112) and have an opening formed at the top thereof, and the top lid (1104) may be coupled to the body portion (1102) so as to cover the opening of the body portion (1102).

[0031] A gas injection unit (120) may be installed in the process chamber (110) to supply a process gas to the reaction space (112). More specifically, the gas injection unit (120) may be installed in the process chamber (110) to face the substrate support unit (130). For example, the gas injection unit (120) may be installed at the top of the process chamber (110) to inject a process gas onto a substrate (S) mounted on the substrate support unit (130).

[0032] In some embodiments, the gas injection unit (120) may include an inlet (122) through which process gas is introduced through a gas pipe (126), and a distribution plate (124) for injecting the process gas introduced through the inlet (122) and dispersed within the unit into the reaction space (112). Optionally, the gas injection unit (120) may further include a blocker plate therein for dispersing the process gas passing through the inlet (122).

[0033] In some embodiments, the gas injection unit (120) may have various shapes, such as a shower head shape, a nozzle shape, etc. When the gas injection unit (120) is a shower head shape, the gas injection unit (120) may be coupled to the process chamber (110) in a shape that partially covers the upper portion of the process chamber (110). For example, the gas injection unit (120) may be coupled to the top lid (1104) of the process chamber (110).

[0034] The substrate support (130) may be coupled to the process chamber (110) to support the substrate (S). For example, the substrate support (130) may be installed in the process chamber (110) facing the gas injection unit (120). The substrate support (130) may include an upper plate (132) on which the substrate (S) is mounted and a shaft (135) for supporting the upper plate (132).

[0035] Optionally, the substrate support (130) may include a heater (182) for heating the substrate (S) within its upper surface. For example, the heater (182) may include one or more heating wires. A heater power supply (180) for supplying power to the heater (182) may be connected. Optionally, an AC filter (185) may be connected between the heater power supply (180) and the heater (182).

[0036] The shape of the upper plate (132) in the substrate support member (130) generally corresponds to the shape of the substrate (S), but is not limited thereto, and may be provided in various shapes larger than the substrate (S) so as to stably place the substrate (S). The shaft (135) may be connected to an external motor (not shown) to enable raising and lowering, and optionally, a bellows tube (not shown) may be connected to maintain airtightness. Since the substrate support member (130) is configured to place the substrate (S) thereon, it may also be called a substrate placer, a susceptor, etc.

[0037] Furthermore, the substrate support (130) may include an electrostatic electrode (158) therein. The electrostatic electrode (158) may receive electrostatic power, for example, DC power, from the electrostatic power supply (150). When electrostatic power is applied to the electrostatic electrode (158), an electrostatic force is generated between the substrate (S) and the substrate (S), so that the substrate (S) may be fixed to the upper plate (132) of the substrate support (130). In this case, since the substrate (S) is chucked by the electrostatic force, the substrate support (130) may also be called an electrostatic chuck.

[0038] For example, the electrostatic power supply unit (150) may include a DC power source (152) and a DC filter (155). For example, the DC power source (152) may be electrically connected to an electrostatic electrode (158) to supply an electrostatic voltage to the electrostatic electrode (158). The DC filter (155) may be connected in series with the DC power source (152) to block RF current through the electrostatic electrode (158) from flowing into the DC power source (152). The DC filter (155) may be configured in various forms to block RF current while allowing DC current to pass.

[0039] In some embodiments, the DC power supply (152) may provide a voltage of positive polarity and a voltage of negative polarity, or may alternately provide a voltage of positive polarity and a voltage of negative polarity.

[0040] The RF power supply unit (140) may be connected to the process chamber (110) to supply RF (radio frequency) power for forming a plasma atmosphere in the reaction space (112) inside the process chamber (110). For example, the RF power supply unit (140) may be connected to the gas injection unit (120), in which case the gas injection unit (120) may be referred to as a power supply electrode or an upper electrode. For example, the RF power supply unit (140) may include a high frequency (HF) power source and / or a low frequency (LF) power source.

[0041] Additionally, an impedance matching unit (146) may be placed between the RF power supply unit (140) and the gas injection unit (120) for impedance matching. The impedance matching unit (146) may perform impedance matching between the RF power supply unit (140) and the process chamber (110). The impedance matching unit (146) may be configured as a series or parallel combination of two or more elements selected from the group of resistors, inductors, and capacitors. For example, the impedance matching unit (146) may include at least one variable capacitor.

[0042] In some embodiments, as illustrated in FIG. 2, a plurality of protrusions (1322) may be formed on the surface of the upper plate (132) of the substrate support (130) to form an embossing pattern. The substrate (S) may be placed on these protrusions (1322). As described below, the embossing pattern by these protrusions (1322) may generate a local potential difference when plasma is formed in the reaction space (112) and cause a variation in the sheath voltage, which may cause an imbalance in the film thickness. As described below, the inventor of the present invention considered adjusting the polarity of the voltage applied to the electrostatic electrode (158) in order to resolve the problem of thickness imbalance due to the local potential difference according to the embossing pattern.

[0043] The substrate processing device (100) described above can be used as a chemical vapor deposition (CVD) device or a plasma enhanced chemical vapor deposition (PECVD) device for depositing a thin film on a substrate (S).

[0044] Hereinafter, a substrate processing method according to embodiments of the present invention will be described with reference to a substrate processing device (100). The substrate processing method below is described with reference to the substrate processing device (100) for convenience of explanation, but its scope is not limited to the substrate processing device (100).

[0045] FIG. 3 is a flowchart showing a substrate processing method according to one embodiment of the present invention, and FIG. 4 is a graph showing a voltage applied to an electrostatic electrode according to a process step in the substrate processing method of FIG. 3.

[0046] Referring to FIGS. 1 to 4, the substrate processing method may include a step (S10) of applying a first voltage of a first polarity to an electrostatic electrode (158), a step (S12) of forming a first thin film (F1) on the substrate (S), a step (S20) of applying a second voltage of a second polarity to the electrostatic electrode (158), and a step (S22) of forming a second thin film (F2) on the substrate (S). In this substrate processing method, before this process, the substrate (S) may be introduced into the process chamber (110) and placed on the substrate support (130), and after this process, the substrate (S) may be taken out of the process chamber (110).

[0047] More specifically, in the step of applying a first voltage (S10), a first voltage is applied to the electrostatic electrode (158) to induce an electrostatic force between the substrate (S) and the electrostatic electrode (158), thereby chucking the substrate (S) on the substrate support (130). For example, the first voltage may be applied to the electrostatic electrode (158) from the electrostatic power supply unit (150). The first voltage may be continuously supplied to the electrostatic electrode (158) during the step (S10).

[0048] For example, the first voltage may be a voltage of the first polarity, for example, -V, as illustrated in FIG. 4. However, the scope of the present embodiments is not limited to FIG. 4, and the first voltage may be changed to a voltage of the second polarity opposite to the first polarity, for example, +V.

[0049] The step (S12) of forming the first thin film (F1) can be performed by injecting a process gas into the reaction space (112) through the gas injection unit (120) while forming a plasma atmosphere in the reaction space (112) while a first voltage is applied to the electrostatic electrode (158). This step (S12) of forming the first thin film (F1) can be performed at least within the time of the above step (S10). For example, the step (S12) can be performed after the start of the step (S10) and finished before the end of the step (S10), or can be performed to coincide with the period of the step (S10).

[0050] In the step of applying a second voltage (S20), a second voltage is applied to the electrostatic electrode (158) to induce an electrostatic force between the substrate (S) and the electrostatic electrode (158), thereby chucking the substrate (S) onto the substrate support (130). For example, the second voltage may be applied to the electrostatic electrode (158) from the electrostatic power supply unit (150). The second voltage may be continuously supplied to the electrostatic electrode (158) during the step (S20).

[0051] For example, the second voltage may be a voltage of a second polarity opposite to the first polarity, for example, +V, as illustrated in FIG. 4. However, the scope of the present embodiments is not limited to FIG. 4, and when the first voltage is changed to +V, the second voltage may also be changed to -V.

[0052] The step (S22) of forming the second thin film (F2) can be performed by injecting a process gas into the reaction space (112) through the gas injection unit (120) while forming a plasma atmosphere in the reaction space (112) while a second voltage is applied to the electrostatic electrode (158). For example, the second thin film (F2) can be formed to be laminated on the first thin film (F1). This step (S22) of forming the second thin film (F2) can be performed at least within the time of the step (S20) above. For example, the step (S22) can be performed after the start of the step (S20) and finished before the end of the step (S20), or can be performed to coincide with the period of the step (S20).

[0053] In steps (S12, S22), the first thin film (F1) and the second thin film (F2) described above can be formed by injecting process gases, for example, a source gas and a reaction gas, onto the substrate (S) in the reaction space (112) from the gas injection unit (120), and by a reaction of the source gas and the reaction gas, for example, a chemical vapor reaction. This reaction can be further activated in a plasma atmosphere in the reaction space (112). For example, the first thin film (F1) and the second thin film (F2) can be formed by a plasma-enhanced chemical vapor deposition (PECVD) method. Furthermore, the first thin film (F1) and the second thin film (F2) can be formed continuously in-situ in the same process chamber (110).

[0054] In some embodiments, the substrate processing method may include a step of sequentially repeating the steps of applying the first voltage (S10), forming the first thin film (F1) (S12), applying the second voltage (S20), and forming the second thin film (F2) (S22) multiple times. Accordingly, the first thin film (F1) and the second thin film (F2) may be alternately laminated on the substrate (S). In some embodiments, the absolute values ​​of the first voltage and the second voltage may be gradually increased each time the number of repetitions increases. Accordingly, it is expected that the polarity toggling effect of the voltage applied to the electrostatic electrode (158) can be further enhanced.

[0055] The above-described number of repetitions can be appropriately selected depending on the total thickness of the required thin film. For example, the above-described steps (S10, S12, S20, S22) can be repeated a set number of times (n times). For example, it can be checked whether the set number of repetitions has been reached (S30), and if so, the process can be terminated. If the number of repetitions is less than the set number of repetitions, the above-described steps (S10, S12, S20, S22) can be repeated.

[0056] In some embodiments, the first thin film (F1) and the second thin film (F2) may be thin films of the same material, for example, including the same insulating material. For example, the first thin film (F1) and the second thin film (F2) may be oxide films or nitride films. In this case, when forming a thick thin film of the same material, in order to resolve the thickness unevenness that occurs when the same polarity voltage is continuously applied to the electrostatic electrode (158), the polarity of the voltage applied to the electrostatic electrode (158) may be toggled during thin film formation. By toggling the voltage applied to the electrostatic electrode (158) in this way, the thickness unevenness can be further reduced.

[0057] In some embodiments, the first thin film (F1) and the second thin film (F2) may be thin films of different materials. In this case, the second thin film (F2) is continuously formed on the first thin film (F1), and the total thickness of the thin film increases. In order to resolve the thickness unevenness that occurs when the same polarity voltage is continuously applied to the electrostatic electrode (158), the polarity of the voltage applied to the electrostatic electrode (158) can be toggled during the entire thin film formation.

[0058] According to the substrate processing method described above, when manufacturing a high-thickness identical thin film or a heterogeneous thin film stack, the polarity of the voltage applied to the electrostatic electrode (158) can be repeatedly toggled to reduce deformation and unevenness of the sheath voltage due to fixation of the electrostatic voltage, and as a result, the thickness uniformity of the thin film can be increased.

[0059] Fig. 5 is a flowchart showing a substrate processing method according to another embodiment of the present invention, and Fig. 6 is a graph showing voltages applied to electrostatic electrodes according to process steps in the substrate processing method of Fig. 5. The substrate processing method according to this embodiment is a method in which some components are added or modified from the substrate processing methods of Figs. 3 and 4, and since the embodiments can be referenced to each other, redundant descriptions in the embodiments are omitted.

[0060] Referring to FIGS. 1, 2, 5 and 6, the substrate processing method may include a step (S10) of applying a first voltage of a first polarity to an electrostatic electrode (158), a step (S12) of forming a first thin film (F1) on a substrate (S), a step (S14) of forming a third thin film (F3) on the substrate (S), a step (S20) of applying a second voltage of a second polarity to the electrostatic electrode (158), a step (S22) of forming a second thin film (F2) on the substrate (S), and a step (S24) of forming a fourth thin film (F4) on the substrate (S).

[0061] More specifically, the step (S14) of forming the third thin film (F3) can be performed by injecting a process gas into the reaction space (112) through the gas injection unit (120) while forming a plasma atmosphere in the reaction space (112) while a first voltage is applied to the electrostatic electrode (158). Accordingly, while the first voltage is applied to the electrostatic electrode (158), the first thin film (F1) can be formed on the substrate (S), and then the third thin film (F3) can be formed on the first thin film (F1). Therefore, the step (S14) of forming the third thin film (F3) can be performed after the step (S12) of forming the first thin film (F1) and before the step (S20) of applying the second voltage.

[0062] The combined time of the step (S12) of forming the first thin film (F1) and the step (S14) of forming the third thin film (F3) can be performed at least within the time of the above step (S10). For example, the step (S12) can be performed after the start of the step (S10) and the step (S14) can be completed before the end of the step (S10). As another example, the step (S12) can be performed simultaneously with the start of the step (S10) and the step (S14) can be completed simultaneously with the end of the step (S10).

[0063] The step (S24) of forming the fourth thin film (F4) can be performed by injecting a process gas into the reaction space (112) through the gas injection unit (120) while forming a plasma atmosphere in the reaction space (112) while a second voltage is applied to the electrostatic electrode (158). Accordingly, while the second voltage is applied to the electrostatic electrode (158), the second thin film (F2) can be formed on the substrate (S), and then the fourth thin film (F4) can be formed on the second thin film (F2). Therefore, the step (S24) of forming the fourth thin film (F4) can be performed after the step (S22) of forming the second thin film (F2).

[0064] The combined time of the step (S22) of forming the second thin film (F2) and the step (S24) of forming the fourth thin film (F4) can be performed at least within the time of the above step (S20). For example, the step (S22) can be performed after the start of the step (S20) and the step (S24) can be completed before the end of the step (S20). As another example, the step (S22) can be performed simultaneously with the start of the step (S20) and the step (S24) can be completed simultaneously with the end of the step (S20).

[0065] In steps (S12, S14, S22, S24), the first thin film (F1), the third thin film (F3), the second thin film (F2), and the fourth thin film (F4) described above can be formed by injecting process gases, for example, a source gas and a reaction gas, onto the substrate (S) in the reaction space (112) from the gas injection unit (120), and by a reaction of the source gas and the reaction gas, for example, a chemical vapor reaction. For example, the first thin film (F1), the third thin film (F3), the second thin film (F2), and the fourth thin film (F4) can be formed by a plasma enhanced chemical vapor deposition (PECVD) method. Furthermore, the first thin film (F1), the third thin film (F3), the second thin film (F2), and the fourth thin film (F4) can be formed continuously in-situ within the same process chamber (110).

[0066] In some embodiments, the substrate processing method may include a step of sequentially repeating the steps of applying the first voltage (S10), forming the first thin film (F1), forming the third thin film (F3) (S14), applying the second voltage (S20), forming the second thin film (F2) (S22), and forming the fourth thin film (F4) (S24) multiple times. Accordingly, the first thin film (F1), the third thin film (F3), the second thin film (F2), and the fourth thin film (F4) may be alternately laminated on the substrate (S).

[0067] In some embodiments, the absolute values ​​of the first and second voltages may be gradually increased as the number of repetitions described above increases. Accordingly, the polarity toggling effect of the voltage applied to the electrostatic electrode (158) can be further enhanced, thereby further reducing thickness non-uniformity of the entire thin film.

[0068] The above-described number of repetitions can be appropriately selected depending on the total thickness of the required thin film. For example, the above-described steps (S10, S12, S14, S20, S22, S24) can be repeated a set number of times (n times). For example, it can be checked whether the set number of repetitions has been reached (S30), and if so, the process can be terminated. If the number of repetitions is less than the set number of repetitions, the above-described steps (S10, S12, S14, S20, S22, S24) can be repeated.

[0069] In some embodiments, the first thin film (F1), the third thin film (F3), the second thin film (F2), and the fourth thin film (F4) may have a laminated structure. Furthermore, the first thin film (F1) and the second thin film (F2) may include the same first insulator, and the third thin film (F3) and the fourth thin film (F4) may include the same second insulator. For example, the first insulator may be an oxide film, and the second insulator may be a nitride film. In another example, the first insulator may be a nitride film, and the second insulator may be an oxide film.

[0070] In some embodiments, the first thin film (F1), the third thin film (F3), the second thin film (F2), and the fourth thin film (F4) may include an alternating stacked structure of oxide / nitride / oxide / nitride or an alternating stacked structure of nitride / oxide / nitride / oxide. For example, such an alternating stacked structure of films may be used as a mold structure in the manufacture of ultra-high-end semiconductor devices, such as ultra-high-end VNAND.

[0071] According to the substrate processing method described above, when manufacturing an ultra-high-speed alternating layered film, the polarity of the voltage applied to the electrostatic electrode (158) can be repeatedly toggled, thereby preventing an uneven pattern formed along an embossing pattern when depositing a thin film on a substrate (S) and increasing the thickness uniformity of the thin film.

[0072] Fig. 7 is a flowchart showing a substrate processing method according to another embodiment of the present invention. The substrate processing method according to this embodiment is a method that adds or modifies some components to the substrate processing methods of Figs. 5 and 6, and since the embodiments can be referenced to each other, any duplicate descriptions in the embodiments are omitted.

[0073] Referring to FIG. 7, the substrate processing method may include a step (S10) of applying a first voltage of a first polarity to an electrostatic electrode (158), a step (S12) of forming a first thin film (F1) on a substrate (S), a step (S14) of forming a third thin film (F3) on the substrate (S), a step (S15) of repeating steps (S12, S14) multiple times, a step (S20) of applying a second voltage of a second polarity to the electrostatic electrode (158), a step (S22) of forming a second thin film (F2) on the substrate (S), a step (S24) of forming a fourth thin film (F4) on the substrate (S), and a step (S25) of repeating steps (S22, S24) multiple times.

[0074] In the repeating step (S15), before the step (S20) of applying the second voltage to the electrostatic electrode (158), the step (S12) of forming the first thin film (F1) and the step (S14) of forming the third thin film (F3) may be sequentially repeated multiple times while the first voltage is applied to the electrostatic electrode (158). Accordingly, before the voltage applied to the electrostatic electrode (158) is toggled from the first voltage to the second voltage, alternating thin films of the first thin film (F1) / third thin film (F3) can be repeatedly deposited on the substrate (S) to an appropriate thickness.

[0075] In the repeating step (S25), after the step (S20) of applying a second voltage to the electrostatic electrode (158), the step (S22) of forming a second thin film (F2) and the step (S24) of forming a fourth thin film (F4) while the second voltage is applied to the electrostatic electrode (158) may be sequentially repeated multiple times. Accordingly, before the voltage applied to the electrostatic electrode (158) is switched from the second voltage to the first voltage again, alternating thin films of the second thin film (F2) / fourth thin film (F4) can be repeatedly deposited on the substrate (S) to an appropriate thickness.

[0076] In some embodiments, one of the repeating steps (S15, S25) in the substrate processing method may be omitted. For example, the repeating step (S15) in the substrate processing method may be omitted, or the repeating step (S25) may be omitted. Depending on the polarity of the voltage applied to the electrostatic electrode (158), it may be considered to omit some of the repeating steps (S15, S25).

[0077] According to the substrate processing method described above, productivity can be increased by controlling the toggle cycle of the voltage in consideration of the thickness at which deformation and unevenness of the sheath voltage occur depending on the voltage applied to the electrostatic electrode (158).

[0078] Figures 8, 9, and 10 are graphs showing the thickness uniformity of thin films formed according to the substrate processing method according to Comparative Example 1, Comparative Example 2, and the Example. Comparative Example 1 shows a case where only -V was applied to the electrostatic electrode (158) during the process, Comparative Example 2 shows a case where only +V was applied to the electrostatic electrode (158) during the process, and the Example shows a case where +V and -V voltages were applied multiple times while toggling them to the electrostatic electrode (158) during the process.

[0079] Referring to Fig. 8, in Comparative Example 1, when only -V is applied to the electrostatic electrode (158), it can be seen that the thickness non-uniformity of the thin film occurs along the embossing pattern of the protrusions (1322) due to a local potential difference near the substrate (S).

[0080] Referring to FIG. 9, in Comparative Example 2, when only +V voltage is applied to the electrostatic electrode (158), it can be seen that the sheath voltage is deformed near the gas injection unit (120), and as this deformation moves away from the substrate (S), the thickness unevenness of the thin film is alleviated.

[0081] Referring to FIG. 10, it can be seen that when the voltage applied to the electrostatic electrode (158) in the embodiment is periodically toggled to +V voltage or -V voltage, the thickness unevenness of the thin film that occurs along the embossing pattern of the protrusions (1322) is offset, and the thickness unevenness of the entire thin film is greatly reduced.

[0082] Therefore, it can be seen that the thickness non-uniformity of the thin film is the lowest in the example, then slightly higher in comparative example 2, and significantly higher in comparative example 1.

[0083] Figure 11 is a graph showing the number of particles on substrates formed according to the substrate processing method according to Comparative Example 1, Comparative Example 2, and the embodiment.

[0084] Referring to Fig. 11, it can be seen that the number of particles on the substrate (S) is significantly increased in Comparative Example 2 compared to the embodiment. This can be understood as the result of non-uniform thin film deposition on the gas injection unit (120) causing particles. Comparative Example 1 shows a number of particles similar to or slightly higher than that of the embodiment. Therefore, in terms of the number of particles, it can be seen that it is low in Comparative Example 1 and the embodiment, and very high in Comparative Example 2.

[0085] Therefore, in terms of the non-uniformity of the film thickness, the Example and Comparative Example 2 can be selected, and in terms of the number of particles, the Example and Comparative Example 1 can be selected. Therefore, when the non-uniformity of the film thickness and the number of particles are comprehensively considered, it can be seen that the Example is superior to Comparative Examples 1 and 2.

[0086] Therefore, according to the substrate processing methods according to embodiments of the present invention, when depositing a thick thin film or performing ultra-high-speed alternating deposition of a heterogeneous thin film, process stability can be improved by reducing thickness non-uniformity and reducing particles.

[0087] While the present invention has been described with reference to the embodiments illustrated in the drawings, these are merely exemplary, and those skilled in the art will appreciate that various modifications and equivalent alternative embodiments are possible. Therefore, the true scope of technical protection of the present invention should be determined by the technical spirit of the appended claims.

Claims

1. A substrate processing method using a substrate processing device including a process chamber having a reaction space formed therein, a substrate support unit coupled to the process chamber to support a substrate and including an electrostatic electrode therein, and a gas injection unit installed in the process chamber to supply a process gas to the reaction space. A step of applying a first voltage of a first polarity to the above electrostatic electrode; A step of forming a first thin film on the substrate by injecting a process gas into the reaction space through the gas injection unit while forming a plasma atmosphere in the reaction space while the first voltage is applied to the electrostatic electrode; A step of applying a second voltage of a second polarity opposite to the first polarity to the electrostatic electrode; and Including a step of forming a second thin film on the substrate by injecting a process gas into the reaction space through the gas injection unit while forming a plasma atmosphere in the reaction space while the second voltage is applied to the electrostatic electrode. Method of substrate processing.

2. In paragraph 1, A substrate processing method comprising a step of sequentially repeating the steps of applying the first voltage, forming the first thin film, applying the second voltage, and forming the second thin film multiple times.

3. In paragraph 1, A substrate processing method, wherein the first thin film and the second thin film comprise the same insulating material.

4. In paragraph 1, After the step of forming the first thin film and before the step of applying the second voltage, a step of forming a third thin film on the substrate is included, in which the first voltage is applied to the electrostatic electrode, a process gas is injected into the reaction space through the gas injection unit while forming a plasma atmosphere in the reaction space. After the step of forming the second thin film, a step of forming a fourth thin film on the substrate by injecting a process gas into the reaction space through the gas injection unit while forming a plasma atmosphere in the reaction space while the second voltage is applied to the electrostatic electrode is included. Method of substrate processing.

5. In paragraph 4, A substrate processing method comprising a step of sequentially repeating the steps of applying the first voltage, forming the first thin film, forming the third thin film, applying the second voltage, forming the second thin film, and forming the fourth thin film multiple times.

6. In paragraph 5, A substrate processing method in which, in the step of repeating the above multiple times, the absolute values ​​of the first voltage and the second voltage gradually increase with each repetition.

7. In paragraph 4, A substrate processing method, wherein the step of forming the first thin film and the step of forming the third thin film are alternately performed multiple times before the step of applying the second voltage.

8. In paragraph 4, A substrate processing method, wherein, after the step of applying the second voltage, the step of forming the second thin film and the step of forming the fourth thin film are alternately performed multiple times.

9. In paragraph 4, The first thin film, the third thin film, the second thin film and the fourth thin film have a laminated structure, The first thin film and the second thin film comprise the same first insulator, The third thin film and the fourth thin film comprise the same second insulator, Method of substrate processing.

10. In paragraph 9, A substrate processing method, wherein the laminated structure of the first thin film, the third thin film, the second thin film, and the fourth thin film includes an alternating laminated structure of oxide film / nitride film / oxide film / nitride film or an alternating laminated structure of nitride film / oxide film / nitride film / oxide film.

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