Substrate processing method

Abstract

A substrate processing method according to one aspect of the present invention is a substrate processing method using a substrate processing apparatus comprising a process chamber, a substrate support member including an electrostatic electrode inside, and a gas injection member, comprising the steps of: applying a first voltage of a first polarity to the electrostatic electrode; forming a first thin film on the substrate while 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 while the second voltage is applied to the electrostatic electrode.

Description

Technology Field

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

[0002] To manufacture semiconductor devices, various substrate processing processes are performed in a substrate processing apparatus under a vacuum atmosphere. For example, a substrate may be loaded into a process chamber, and processes such as depositing a thin film or etching a thin film on the substrate may be carried out. The substrate is placed on a substrate support installed inside the process chamber and can be chucked to the substrate support using electrostatic force.

[0003] Recently, as thin films formed on substrates become thicker or the height of alternating stacked thin films increases, thickness non-uniformity has become an issue. As the height of single or stacked thin films increases, a uniform color pattern is formed on the film, leading to thickness non-uniformity. Furthermore, attempts to reduce thickness non-uniformity result in the problem of increased particle formation on the thin film. The problem to be solved

[0004] The present invention aims to solve various problems, including those mentioned above, by providing a substrate processing method that can improve process stability by suppressing particle generation while reducing thickness non-uniformity that occurs as the height of a single or stacked thin film increases. However, this problem is exemplary and does not limit the scope of the present invention. means of solving the problem

[0005] A substrate processing method according to one aspect of the present invention for solving the above problem is a substrate processing method using a substrate processing apparatus comprising: a process chamber having a reaction space formed therein; a substrate support member coupled to the process chamber to support a substrate and including an electrostatic electrode inside; and a gas injection unit installed in the process chamber to supply process gas to the reaction space, the method comprising: a step of applying a first voltage of a first polarity to the electrostatic electrode; a step of forming a first thin film on the substrate by injecting 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 a step of forming a second thin film on the substrate by injecting 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.

[0006] The above substrate processing method may include the step of applying the first voltage, the step of forming the first thin film, the step of applying the second voltage, and the step of forming the second thin film, repeating these steps in sequence a plurality of 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-described 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 the 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 while the first voltage is applied to the electrostatic electrode, and after the step of forming the second thin film, the method may include the 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.

[0009] The above substrate processing method may include 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, which are repeated a plurality of times in sequence.

[0010] In the above-described substrate processing method, in the step of repeating multiple times, the absolute values ​​of the first voltage and the second voltage may gradually increase each time the process is repeated.

[0011] In the above substrate processing method, prior to 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 performed alternately a plurality of 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 performed alternately a plurality of 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 stacked structure, the first thin film and the second thin film include the same first insulating material, and the third thin film and the fourth thin film may include the same second insulating material.

[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. Effects of the invention

[0015] According to the substrate processing method of some embodiments of the present invention as described above, the polarity of the voltage applied to the electrostatic electrode in the middle during thin film deposition is toggled to increase the thickness uniformity of the thin film and suppress particle generation, thereby increasing process stability. Of course, the scope of the present invention is not limited by this effect. Brief explanation of the drawing

[0016] FIG. 1 is a schematic cross-sectional view showing a substrate processing apparatus according to one embodiment of the present invention. Figure 2 is a schematic partial cross-sectional view of the substrate support portion of the substrate processing device of Figure 1. FIG. 3 is a flowchart showing a substrate processing method according to one embodiment of the present invention. Figure 4 is a graph showing the voltage applied to the electrostatic electrode according to the process step in the substrate processing method of Figure 3. FIG. 5 is a flowchart showing a substrate processing method according to another embodiment of the present invention. Figure 6 is a graph showing the voltage applied to the electrostatic electrode according to the process step in the substrate processing method of Figure 5. FIG. 7 is a flowchart showing a substrate processing method according to another embodiment of the present invention. FIGS. 8, 9, and 10 are graphs showing the thickness uniformity of thin films formed according to the substrate processing methods of Comparative Example 1, Comparative Example 2, and the embodiment. FIG. 11 is a graph showing the number of particles on substrates formed according to the substrate processing methods of Comparative Example 1, Comparative Example 2, and the embodiment. Specific details for implementing the invention

[0017] Hereinafter, several preferred embodiments of the present invention will be described in detail with reference to the attached drawings.

[0018] The embodiments of the present invention are provided to more fully explain the invention to those skilled in the art, and the following embodiments may be modified in various different forms, and the scope of the invention is not limited to the following embodiments. Rather, these embodiments are provided to make the disclosure more faithful and complete and to fully convey the spirit of the invention to those skilled in the art. In addition, the thickness or size of each layer in the drawings is exaggerated for convenience and clarity of explanation.

[0019] FIG. 1 is a schematic diagram 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 portion of the substrate processing device (100) of FIG. 1.

[0020] 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).

[0021] More specifically, a reaction space (112) in which a substrate (S) can be processed may be formed in the process chamber (110). The process chamber (110) may be connected to a vacuum pump (not shown) through an exhaust pipe (114) to create a vacuum atmosphere. A throttle valve (117) for controlling the opening rate may be installed in the exhaust pipe (114). The throttle valve (117) may be used to control the pressure in the reaction space (112) within the process chamber (110).

[0022] Furthermore, the process chamber (110) may be equipped with an entrance / exit for loading a substrate (S) into or from the reaction space (112) and a gate structure (not shown) for opening and closing the same. The process chamber (110) may be provided in various shapes and, for example, may include a body portion (1102) and a top lead (1104). For example, the body portion (1102) may define the reaction space (112) and have an opening formed at its top, and the top lead (1104) may be coupled to the body portion (1102) to cover the opening of the body portion (1102).

[0023] A gas injection unit (120) may be installed in a process chamber (110) to supply process gas to a reaction space (112). More specifically, the gas injection unit (120) may be installed in the process chamber (110) so as to face a substrate support (130). For example, the gas injection unit (120) may be installed at the top of the process chamber (110) to inject process gas onto a substrate (S) placed on the substrate support (130).

[0024] In some embodiments, the gas injection unit (120) may include an inlet (122) into 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 internally into a reaction space (112). Optionally, the gas injection unit (120) may further include a blocker plate internally for dispersing the process gas that has passed through the inlet (122).

[0025] In some embodiments, the gas injection unit (120) may have various forms, such as a shower head or a nozzle. If the gas injection unit (120) is in the form of a shower head, the gas injection unit (120) may be coupled to the process chamber (110) in a manner that partially covers the upper part 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).

[0026] A substrate support member (130) may be coupled to a process chamber (110) to support a substrate (S). For example, the substrate support member (130) may be installed in the process chamber (110) opposite to a gas injection member (120). The substrate support member (130) may include a top plate (132) on which the substrate (S) is placed and a shaft (135) for supporting it.

[0027] Optionally, the substrate support (130) may include a heater (182) for heating the substrate (S) inside the top plate. For example, the heater (182) may include one or more heating wires. A heater power supply (180) for applying power may be connected to the heater (182). Optionally, an AC filter (185) may be connected between the heater power supply (180) and the heater (182).

[0028] The shape of the top plate (132) in the substrate support (130) generally corresponds to the shape of the substrate (S), but is not limited thereto and can be provided in various shapes larger than the substrate (S) so as to stably seat the substrate (S). The shaft (135) may be connected to an external motor (not shown) to enable vertical movement, and optionally, a bellows tube (not shown) may be connected to maintain airtightness. Since the substrate support (130) is configured to seat the substrate (S) thereon, it may also be called a substrate seating part, a susceptor, etc.

[0029] Furthermore, the substrate support (130) may include an electrostatic electrode (158) inside. The electrostatic electrode (158) may receive electrostatic power, such as DC power, from an electrostatic power supply unit (150). When electrostatic power is applied to the electrostatic electrode (158), an electrostatic force is generated between it and the substrate (S), so that the substrate (S) can be fixed to the top plate (132) of the substrate support (130). In this case, the substrate support (130) may be called an electrostatic chuck in that the substrate (S) is chucked by the electrostatic force.

[0030] For example, the constant 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 the electrostatic electrode (135) to supply a constant voltage to the electrostatic electrode (135). The DC filter (155) may be connected in series to the DC power source (152) to block RF current from flowing into the DC power source (152) through the electrostatic electrode (135). The DC filter (155) may be configured in various forms to block RF current while allowing DC current to pass through.

[0031] In some embodiments, the DC power supply (152) may provide a voltage of positive polarity and a voltage of negative polarity, respectively, or provide the positive polarity voltage and the negative polarity voltage alternately.

[0032] An RF power supply unit (140) may be connected to a process chamber (110) to supply RF (radio frequency) power to form a plasma atmosphere in a reaction space (112) inside the process chamber (110). For example, the RF power supply unit (140) may be connected to a gas injection unit (120), in which case the gas injection unit (120) may be called a power supply electrode or an upper electrode. For example, the RF power supply unit (140) may include a high frequency (HF) power supply and / or a low frequency (LF) power supply.

[0033] Additionally, an impedance matching unit (146) may be positioned 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 composed of two or more series or parallel combinations selected from the group of resistors, inductors, and capacitors. For example, the impedance matching unit (146) may include at least one variable capacitor.

[0034] In some embodiments, as shown in FIG. 2, a plurality of protrusions (1322) may be formed on the surface of the top plate (1322) 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 formed by these protrusions (1322) may cause a local potential difference when plasma is formed in the reaction space (112) and cause a deformation of the sheath voltage, thereby causing an imbalance in the thin film thickness. As described below, the inventors considered adjusting the polarity of the voltage applied to the electrostatic electrode (158) to resolve the problem of thickness imbalance caused by the local potential difference according to this embossing pattern.

[0035] The above-described substrate processing device (100) 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).

[0036] Hereinafter, a substrate processing method according to embodiments of the present invention is described with reference to a substrate processing device (100). For convenience of explanation, the substrate processing method below is described with reference to a substrate processing device (100), but its scope is not limited to such a substrate processing device (100).

[0037] FIG. 3 is a flowchart showing a substrate processing method according to an embodiment of the present invention, and 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.

[0038] Referring to FIGS. 1 to 4, the substrate processing method may include the step (S10) of applying a first voltage of a first polarity to an electrostatic electrode (158), the step (S12) of forming a first thin film (F1) on a substrate (S), the step (S20) of applying a second voltage of a second polarity to an electrostatic electrode (158), and the step (S22) of forming a second thin film (F2) on a substrate (S). In this substrate processing method, before this process, the substrate (S) may be introduced into a process chamber (110) and placed on a substrate support (130), and after this process, the substrate (S) may be withdrawn from the process chamber (110).

[0039] More specifically, in the step (S10) of applying the first voltage, the first voltage is applied to the electrostatic electrode (158) to induce an electrostatic force between the substrate (S) and the electrostatic electrode (158), thereby allowing the substrate (S) to be chucked onto the substrate support (130). For example, the first voltage can be applied to the electrostatic electrode (158) from the electrostatic power supply unit (150). The first voltage can be continuously supplied to the electrostatic electrode (158) during the step (S10).

[0040] For example, the first voltage may be a voltage of the first polarity, e.g. -V, as shown in FIG. 4. However, the scope of the 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, e.g. +V.

[0041] The step (S12) of forming the first thin film (F1) can be performed by injecting process gas into the reaction space (112) through the gas injection unit (120) while forming a plasma atmosphere in the reaction space (12) while the 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 terminated before the end of the step (S10), or it can be performed in conjunction with the duration of the step (S10).

[0042] In the step (S20) of applying a second voltage, 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 allowing the substrate (S) to be chucked onto the substrate support (130). For example, the second voltage can be applied to the electrostatic electrode (158) from the electrostatic power supply unit (150). The second voltage can be continuously supplied to the electrostatic electrode (158) during the step (S20).

[0043] For example, the second voltage may be a voltage of the second polarity opposite to the first polarity, e.g., +V, as shown in FIG. 4. However, the scope of these embodiments is not limited to FIG. 4, and if the first voltage is changed to +V, the second voltage may be changed to -V.

[0044] The step (S14) of forming the second thin film (F2) can be performed by injecting process gas into the reaction space (112) through the gas injection unit (120) while forming a plasma atmosphere in the reaction space (12) while the second voltage is applied to the electrostatic electrode (158). For example, the second thin film (F2) can be formed by stacking on the first thin film (F1). The step (S14) of forming the second thin film (F2) can be performed at least within the time of the above step (S20). For example, the step (S14) can be performed after the start of the step (S20) and terminated before the expiration of the step (S20), or it can be performed in conjunction with the duration of the step (S20).

[0045] In steps (S12, S14), the aforementioned first thin film (F1) and second thin film (F2) can be formed by injecting process gases, such as a source gas and a reaction gas, onto a substrate (S) in a reaction space (112) from a gas injection unit (120), and by the reaction of the source gas and the reaction gas, such as 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 chemical vapor deposition (PECVD) method. Furthermore, the first thin film (F1) and the second thin film (F2) can be formed continuously in-situ within the same process chamber (110).

[0046] In some embodiments, the substrate processing method may include the step of applying the aforementioned first voltage (S10), the step of forming a first thin film (F1) (S12), the step of applying a second voltage (S20), and the step of forming a second thin film (F2) (S22), which are repeated multiple times in sequence. Accordingly, the first thin film (F1) and the second thin film (F2) may be alternately stacked 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.

[0047] The aforementioned number of repetitions can be appropriately selected according to the required total thin film thickness. For example, the aforementioned steps (S10, S12, S20, S22) can be performed to be repeated a set number of times (n times). For example, it is checked whether the set number of times has been reached (S30), and if it has been reached, the process is terminated, and if it is less than the set number, the aforementioned steps (S10, S12, S20, S22) can be repeated.

[0048] In some embodiments, the first thin film (F1) and the second thin film (F2) may comprise thin films of the same material, such as 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, the polarity of the voltage applied to the electrostatic electrode (158) during thin film formation can be toggled to eliminate thickness non-uniformity caused by continuously applying a voltage of the same polarity to the electrostatic electrode (158). By toggling the voltage applied to the electrostatic electrode (158) in this way, thickness non-uniformity can be further reduced.

[0049] 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 formed continuously on the first thin film (F1), and as the total thickness of the thin film increases, the polarity of the voltage applied to the electrostatic electrode (158) can be toggled during the entire thin film formation to resolve the thickness non-uniformity caused by continuously applying a voltage of the same polarity to the electrostatic electrode (158).

[0050] According to the above-described substrate processing method, when manufacturing a stack of identical or heterogeneous thin films of high thickness, the polarity of the voltage applied to the electrostatic electrode (158) can be repeatedly toggled to reduce deformation and non-uniformity of the sheath voltage caused by fixing the electrostatic voltage, and as a result, the thickness uniformity of the thin film can be increased.

[0051] 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 the voltage applied to the electrostatic electrode according to the process step in the substrate processing method of FIG. 5. The substrate processing method according to this embodiment is a modified or added configuration to the substrate processing method of FIG. 3 and FIG. 4, and since the embodiments can be referenced to one another, redundant descriptions in the embodiments are omitted.

[0052] Referring to FIGS. 1, 2, 5 and 6, the substrate processing method may include the step of applying a first voltage of a first polarity to an electrostatic electrode (158) (S10), the step of forming a first thin film (F1) on a substrate (S) (S12), the step of forming a third thin film (F3) on a substrate (S) (S14), the step of applying a second voltage of a second polarity to an electrostatic electrode (158) (S20), the step of forming a second thin film (F2) on a substrate (S) (S22), and the step of forming a fourth thin film (F4) on a substrate (S) (S24).

[0053] More specifically, the step (S14) of forming the third thin film (F3) can be performed by forming a plasma atmosphere in the reaction space (12) while the first voltage is applied to the electrostatic electrode (158) and injecting process gas into the reaction space (112) through the gas injection unit (120). Accordingly, while the first voltage is applied to the electrostatic electrode (158), the first thin film (F1) is formed on the substrate (S), and subsequently, 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.

[0054] 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 within at least the time of the above step (S10). For example, step (S12) can be performed after the start of step (S10) and step (S14) can be terminated before the expiration of step (S10). As another example, step (S12) can be performed simultaneously with the start of step (S10) and step (S14) can be terminated simultaneously with the expiration of step (S10).

[0055] The step (S24) of forming the fourth thin film (F4) can be performed by injecting process gas into the reaction space (112) through the gas injection unit (120) while forming a plasma atmosphere in the reaction space (12) while the 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) is formed on the substrate (S), and subsequently, 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).

[0056] 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 within at least the time of the above step (S20). For example, step (S22) can be performed after the start of step (S20) and step (S24) can be terminated before the expiration of step (S20). As another example, step (S22) can be performed simultaneously with the start of step (S20) and step (S24) can be terminated simultaneously with the expiration of step (S20).

[0057] In steps (S12, S14, S22, S24), the aforementioned first thin film (F1), third thin film (F3), second thin film (F2), and fourth thin film (F5) can be formed by injecting process gases, such as a source gas and a reaction gas, onto a substrate (S) in a reaction space (112) from a gas injection unit (120), and by the reaction of the source gas and the reaction gas, such as a chemical vapor reaction. For example, the first thin film (F1), third thin film (F3), second thin film (F2), and fourth thin film (F5) can be formed by a plasma chemical vapor deposition (PECVD) method. Furthermore, the first thin film (F1), third thin film (F3), second thin film (F2), and fourth thin film (F5) can be formed continuously in-situ within the same process chamber (110).

[0058] In some embodiments, the substrate processing method may include the step of applying the aforementioned first voltage (S10), the step of forming a first thin film (F1) (S12), the step of forming a third thin film (F3) (S14), the step of applying a second voltage (S20), the step of forming a second thin film (F2) (S22), and the step of forming a fourth thin film (F4) (S24), which are repeated multiple times in sequence. 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 stacked on the substrate (S).

[0059] In some embodiments, the absolute values ​​of the first voltage and the second voltage may be gradually increased each time the aforementioned number of repetitions increases. Accordingly, the polarity toggle effect of the voltage applied to the electrostatic electrode (158) can be further increased, thereby further reducing the thickness non-uniformity of the entire thin film.

[0060] The aforementioned number of repetitions can be appropriately selected according to the required total thin film thickness. For example, the aforementioned steps (S10, S12, S14, S20, S22, S24) can be performed to be repeated a set number of times (n times). For example, it is checked whether the set number of times has been reached (S30), and if it has been reached, the process is terminated, and if it is less than the set number, the aforementioned steps (S10, S12, S14, S20, S22, S24) can be repeated.

[0061] 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 stacked structure. Furthermore, the first thin film (F1) and the second thin film (F2) may include the same first insulating material, and the third thin film (F3) and the fourth thin film (F4) may include the same second insulating material. For example, the first insulating material may be an oxide film and the second insulating material may be a nitride film. As another example, the first insulating material may be a nitride film and the second insulating material may be an oxide film.

[0062] 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 may be used as a mold structure when manufacturing an ultra-high-density semiconductor device, such as an ultra-high-density VNAND.

[0063] According to the above-described substrate processing method, when manufacturing an ultra-high-layer alternating laminated film, the polarity of the voltage applied to the electrostatic electrode (158) can be repeatedly toggled, and accordingly, when depositing a thin film on the substrate (S), a non-uniform pattern formed along the embossing pattern can be prevented and the thickness uniformity of the thin film can be increased.

[0064] 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 modified or modified version of the substrate processing method of FIG. 5 and FIG. 6, and since the embodiments can be referenced to one another, redundant descriptions in the embodiments are omitted.

[0065] Referring to FIG. 7, the substrate processing method may include the step of applying a first voltage of a first polarity to an electrostatic electrode (158) (S10), the step of forming a first thin film (F1) on a substrate (S) (S12), the step of forming a third thin film (F3) on a substrate (S) (S14), the step of repeating the steps (S12, S14) multiple times (S15), the step of applying a second voltage of a second polarity to an electrostatic electrode (158) (S20), the step of forming a second thin film (F2) on a substrate (S) (S22), the step of forming a fourth thin film (F4) on a substrate (S) (S24), and the step of repeating the steps (S22, S24) multiple times (S25).

[0066] In the repeating step (S15), prior to the step (S20) of applying a second voltage to the electrostatic electrode (158), the step (S12) of forming a first thin film (F1) and the step (S14) of forming a third thin film (F3) can be repeated multiple times in sequence while the first voltage is applied to the electrostatic electrode (158). According to this, before toggling the voltage applied to the electrostatic electrode (158) from the first voltage to the second voltage, alternating thin films of the first thin film (F1) and the third thin film (F3) can be repeatedly deposited on the substrate (S) to an appropriate thickness.

[0067] 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) can be repeated multiple times in sequence while the second voltage is applied to the electrostatic electrode (158). According to this, before toggling the voltage applied to the electrostatic electrode (158) from the second voltage back to the first voltage, alternating thin films of the second thin film (F2) and the fourth thin film (F4) can be repeatedly deposited on the substrate (S) to an appropriate thickness.

[0068] 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), some of the repeating steps (S15, S25) may be omitted.

[0069] According to the above-described substrate processing method, productivity can be increased by adjusting the voltage toggle cycle, taking into account the thickness at which deformation and non-uniformity of the sheath voltage occur depending on the voltage applied to the electrostatic electrode (158).

[0070] FIGS. 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 is a case where only -V is applied to the electrostatic electrode (158) during the process, Comparative Example 2 is a case where only +V is applied to the electrostatic electrode (158) during the process, and the Example shows a case where +V and -V voltages are toggled and applied multiple times to the electrostatic electrode (158) during the process.

[0071] Referring to FIG. 8, it can be seen that when only -V is applied to the electrostatic electrode (158) in Comparative Example 1, 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).

[0072] Referring to FIG. 9, in Comparative Example 2, when only a +V voltage is applied to the electrostatic electrode (158), the sheath voltage near the gas injection part (120) is deformed, and as this deformation moves away from the substrate (S), the thickness non-uniformity of the thin film is alleviated.

[0073] Referring to FIG. 10, in the embodiment, when the voltage applied to the electrostatic electrode (158) is periodically toggled to a +V voltage or a -V voltage, it can be seen that the thickness non-uniformity of the thin film occurring along the embossing pattern of the protrusions (1322) is offset, and the thickness non-uniformity of the entire thin film is greatly reduced.

[0074] Therefore, it can be seen that the thickness non-uniformity of the thin film is lowest in the example, then slightly higher in Comparative Example 2, and significantly higher in Comparative Example 1.

[0075] FIG. 11 is a graph showing the number of particles on substrates formed according to the substrate processing methods of Comparative Example 1, Comparative Example 2, and the embodiment.

[0076] Referring to FIG. 11, it can be seen that the number of particles on the substrate (S) in Comparative Example 2 is significantly increased compared to the Example. This can be understood as non-uniform thin film deposition on the gas injection unit (120) causing particles. In the case of Comparative Example 1, the number of particles is similar to or slightly higher than that of the Example. Therefore, in terms of the number of particles, it can be seen that it is low in Comparative Example 1 and the Example, and very high in Comparative Example 2.

[0077] Therefore, regarding the non-uniformity of the thin film thickness, the Example and Comparative Example 2 can be selected, and regarding the number of particles, the Example and Comparative Example 1 can be selected. Thus, when comprehensively considering the non-uniformity of the thin film thickness and the number of particles, it can be seen that the Example is superior to Comparative Example 1 and Comparative Example 2.

[0078] Accordingly, according to the substrate processing methods of the embodiments of the present invention, when depositing a thick thin film or ultra-high-step alternating deposition of heterogeneous thin films, process stability can be improved by reducing thickness non-uniformity and reducing particles.

[0079] The present invention has been described with reference to the embodiments illustrated in the drawings, but this is merely illustrative, and those skilled in the art will understand that various modifications and equivalent alternative embodiments are possible therefrom. Accordingly, the true technical scope of protection of the present invention should be determined by the technical spirit of the appended claims. Explanation of the symbols

[0080] 100: Substrate processing device 110: Process chamber 120: Gas injection unit 130: Substrate support 132: Top plate 135: Shaft 140: RF Power Supply 150: Constant power supply 158: Electrostatic electrode

Claims

Claim 1 A substrate processing method using a substrate processing apparatus comprising: a process chamber having a reaction space formed therein; a substrate support member coupled to the process chamber to support a substrate and including an electrostatic electrode inside; and a gas injection unit installed in the process chamber to supply process gas to the reaction space, the method comprising: a step of applying a first voltage of a first polarity to the electrostatic electrode; a step of forming a first thin film on the substrate by injecting 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; and a step of applying a second voltage of a second polarity opposite to the first polarity to the electrostatic electrode. A substrate processing method comprising: a step of forming a second thin film on a substrate by injecting a process gas into the reaction space through a gas injection unit while forming a plasma atmosphere in the reaction space while the second voltage is applied to the electrostatic electrode; a step of forming a third thin film on the substrate by injecting a process gas into the reaction space through a gas injection unit while forming a plasma atmosphere in the reaction space while the first voltage is applied to the electrostatic electrode before the step of applying the second voltage, after the step of forming the first thin film and before the step of applying the second voltage, comprising: a step of forming a fourth thin film on the substrate by injecting a process gas into the reaction space through a gas injection unit while forming a plasma atmosphere in the reaction space while the second voltage is applied to the electrostatic electrode after the step of forming the second thin film. Claim 2 delete Claim 3 A substrate processing method according to claim 1, wherein the first thin film and the second thin film comprise the same insulating material. Claim 4 delete Claim 5 A substrate processing method according to claim 1, comprising 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, repeating these steps in sequence a plurality of times. Claim 6 A substrate processing method according to claim 5, wherein 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. Claim 7 A substrate processing method according to claim 1, wherein, prior to the step of applying the second voltage, the step of forming the first thin film and the step of forming the third thin film are performed alternately a plurality of times. Claim 8 A substrate processing method according to claim 1, 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 performed alternately a plurality of times. Claim 9 In any one of claims 1, 5 to 8, the first thin film, the third thin film, the second thin film, and the fourth thin film have a stacked structure, the first thin film and the second thin film include the same first insulating material, the third thin film and the fourth thin film include the same second insulating material, and a substrate processing method. Claim 10 A substrate processing method according to claim 9, wherein the stacked structure of the first thin film, the third thin film, the second thin film and the fourth thin film comprises 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.

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