Method for forming aluminum nitride thin film and method for forming thin film including same

Abstract

An embodiment of the present invention relates to a method for forming an aluminum nitride thin film on a substrate supported in a process space inside a chamber, the method comprising the steps of: (a) exposing the substrate to an aluminum-containing gas; (b) exposing the substrate to a nitrogen-containing gas to form an atomic layer or monolayer containing aluminum and nitrogen; and (c) exposing the substrate to a nitrogen-containing plasma, wherein steps (a) to (c) may be repeated multiple times. Therefore, according to embodiments of the present invention, an aluminum nitride single-crystal thin film can be formed at a low temperature. That is, the aluminum nitride thin film can be crystallized even when the temperature of the substrate is adjusted to a low temperature. Therefore, when forming the aluminum nitride single-crystal thin film, it is possible to suppress or prevent damage to an underlying film caused by high-temperature heat.

Description

Method for forming an aluminum nitride thin film and method for forming a thin film including the same

[0001] The present invention relates to a method for forming an aluminum nitride thin film and a method for forming a thin film including the same, and more specifically, to a method for forming an aluminum nitride thin film capable of crystallizing the aluminum nitride thin film at a low temperature and a method for forming a thin film including the same.

[0002] To form an aluminum nitride single crystal thin film, the substrate or the chamber containing the substrate is heated to a temperature of 1000°C or higher. However, when the aluminum nitride thin film is crystallized by heating to a temperature of 1000°C or higher, the underlying film formed underneath may be damaged by the high temperature, resulting in defects. These defects may deteriorate the electrical characteristics of the semiconductor device.

[0003] (Prior art document) Korean registered patent 0638609

[0004] The present invention provides a method for forming an aluminum nitride thin film capable of crystallizing the aluminum nitride thin film at a low temperature and a method for forming a thin film including the same.

[0005] An embodiment of the present invention is a method for forming an aluminum nitride thin film on a substrate supported in a process space inside a chamber, comprising the steps of: (a) exposing the substrate to an aluminum-containing gas; (b) exposing the substrate to a nitrogen-containing gas to form an atomic layer or monolayer containing aluminum and nitrogen; and (c) exposing the substrate to a nitrogen-containing plasma; wherein steps (a) to (c) may be repeated multiple times.

[0006] It may include a step of controlling the temperature of the substrate to 200°C to 600°C.

[0007] In the step of exposing the substrate to a nitrogen-containing plasma, a power of 2.83 mW to 8.49 mW per unit area of ​​the substrate can be applied to the chamber.

[0008] Between the step of exposing the substrate to the aluminum-containing gas and the step of exposing the substrate to the nitrogen-containing gas, a step of exposing the substrate to a nitrogen-containing plasma may be included.

[0009] The above nitrogen-containing plasma can be formed using a gas containing one or more of the elements nitrous oxide (N2O) and nitrogen monoxide (NO).

[0010]

[0011] A method for forming a thin film according to an embodiment of the present invention may include a step of loading a substrate having a thin film formed on one surface into a chamber; and a step of forming an aluminum nitride thin film on the thin film using the method described above.

[0012]

[0013] A method for forming a thin film according to an embodiment of the present invention may include: forming an aluminum nitride thin film on a substrate by the method described above; and forming an upper film of a different type from the aluminum nitride thin film on top of the aluminum nitride thin film, thereby crystallizing the upper film in the crystal direction of the aluminum nitride thin film.

[0014] The upper film may include a single crystal thin film of aluminum scandium nitride (AlScN).

[0015]

[0016] A method for forming an aluminum nitride thin film according to an embodiment of the present invention is a method for forming an aluminum nitride thin film on a substrate placed in a process space of a chamber using a substrate processing device including a chamber having a dome shape at the upper and lower portions, and first and second gas injection units connected to the chamber so as to inject gas into a process space within the chamber, the method comprising the steps of: (a) injecting an aluminum-containing gas into the process space of the chamber using the first gas injection unit, thereby exposing the substrate to the aluminum-containing gas; (b) injecting a nitrogen-containing gas into the process space of the chamber using the second gas injection unit, thereby exposing the substrate to the nitrogen-containing gas, thereby forming an atomic layer or monolayer containing aluminum and nitrogen; and (c) exposing the substrate to a nitrogen-containing plasma; wherein steps (a) to (c) may be repeated a plurality of times.

[0017] The step of exposing the substrate to a nitrogen-containing plasma may include a step of injecting a nitrogen-containing gas into the process space of the chamber using at least one of the first and second gas injectors; and a step of applying power to an antenna installed in the chamber.

[0018] It may include a step of controlling the temperature of the substrate to 200°C to 600°C.

[0019] The above nitrogen-containing plasma can be formed using a nitrogen-containing gas containing one or more of the elements nitrous oxide (N2O) and nitrogen monoxide (NO).

[0020] According to embodiments of the present invention, an aluminum nitride single crystal thin film can be formed at a low temperature. That is, even if the substrate temperature is controlled to a low temperature, the aluminum nitride thin film can be crystallized. Therefore, when forming an aluminum nitride single crystal thin film, damage to the underlying film due to high temperature can be suppressed or prevented.

[0021] Additionally, a thin aluminum nitride single crystal thin film can be formed.

[0022] And, by forming the aluminum nitride thin film as a single crystal, it can be easily formed as a single crystal upper film formed on top of the aluminum nitride thin film.

[0023] FIG. 1 is a drawing showing a state in which an aluminum nitride single crystal thin film is formed on a substrate by a method according to an embodiment of the present invention.

[0024] Figures 2 (a) to (d) are process diagrams conceptually illustrating a method for forming an aluminum nitride single crystal thin film on a substrate using a method according to an embodiment of the present invention.

[0025] FIG. 3 is a schematic drawing of a first type of substrate processing device capable of forming an aluminum nitride single crystal thin film using a method according to an embodiment of the present invention.

[0026] FIG. 4 is a schematic perspective view showing a substrate support part of the first type of substrate processing device illustrated in FIG. 3.

[0027] Fig. 5 is a side cross-sectional view showing a gas injection unit of the first type of substrate processing device illustrated in Fig. 3.

[0028] Fig. 6 is a schematic bottom view of a gas injection unit of the first type of substrate processing device illustrated in Fig. 3.

[0029] FIG. 7 is a schematic bottom view of a gas injection unit according to a modified example in the first type of substrate processing device illustrated in FIG. 3.

[0030] FIG. 8 is a schematic drawing of a second type of substrate processing device capable of forming an aluminum nitride single crystal thin film using a method according to an embodiment of the present invention.

[0031] FIG. 9 is a drawing showing a state in which an upper film is formed on an aluminum nitride single crystal thin film formed by a method according to an embodiment of the present invention.

[0032] Hereinafter, embodiments of the present invention will be described in more detail with reference to the attached drawings. However, the present invention is not limited to the embodiments disclosed below, but may be implemented in various different forms. These embodiments are provided solely to ensure complete disclosure of the present invention and to fully inform those skilled in the art of the scope of the invention. For the purpose of illustrating embodiments of the present invention, the drawings may be exaggerated.

[0033]

[0034] FIG. 1 is a drawing showing a state in which an aluminum nitride single crystal thin film is formed on a substrate by a method according to an embodiment of the present invention.

[0035] Referring to FIG. 1, an aluminum nitride (AlN) single crystal thin film (200) can be formed on a substrate (100). The substrate (100) can be any one of a wafer, glass, and metal. When the substrate (100) is a wafer, the wafer can be any one of a silicon wafer, a silicon carbide wafer, and a gallium arsenide wafer, for example.

[0036] In addition, the substrate (100) may have a predetermined film (hereinafter, lower film (110)) formed on at least one surface, and an aluminum nitride single crystal thin film (200) may be formed on the lower film (110). Here, the lower film (110) is not particularly limited, but may be, for example, at least one of a metal film, an oxide film, a nitride film, and a carbide film.

[0037] The aluminum nitride single crystal thin film (200) may be formed to cover the entire upper surface of the lower film (110) as illustrated in FIG. 1. Of course, the present invention is not limited thereto, and the aluminum nitride single crystal thin film (200) may be formed to expose a portion of the upper surface of the lower film (110). That is, the aluminum nitride single crystal thin film (200) may be formed in some areas of the upper surface of the lower film (110), and the aluminum nitride single crystal thin film (200) may not be formed in the remaining areas.

[0038] In the above, a case in which an aluminum nitride single crystal thin film (200) is formed on a lower film (110) formed on a substrate (100) has been described. However, the present invention is not limited thereto, and an aluminum nitride single crystal thin film (200) may be formed directly on the substrate (100). That is, an aluminum nitride single crystal thin film (200) may be formed on the substrate (100) without a separate lower film (110) being formed.

[0039] An aluminum nitride (AlN) single crystal thin film (200) can be used as at least one of a buffer layer and an insulating film of a semiconductor device. More specifically, the aluminum nitride single crystal thin film (200) can be used as at least one of a buffer layer and an insulating film of at least one of a transistor device and a power semiconductor device. Of course, the aluminum nitride single crystal thin film (200) is not limited to the examples described above, and can be a thin film that can be used in various semiconductor devices.

[0040]

[0041] Figures 2 (a) to (d) are process diagrams conceptually illustrating a method for forming an aluminum nitride single crystal thin film on a substrate using a method according to an embodiment of the present invention.

[0042] Hereinafter, a method for forming an aluminum nitride single crystal thin film (200) on a substrate (100) will be described with reference to (a) to (d) of FIG. 2. At this time, forming an aluminum nitride single crystal thin film (200) on a lower film (110) formed on the substrate (100) will be described as an example.

[0043] A method for forming an aluminum nitride single crystal thin film (200) may include a step of forming an aluminum-containing thin film (210) on a substrate (100) by injecting a source gas containing aluminum (Al) (hereinafter, aluminum-containing source gas) toward a substrate (100), a step of forming an aluminum nitride amorphous thin film (220) by injecting a reactant gas containing nitrogen (N) (hereinafter, nitrogen-containing reactant gas) toward the substrate (100), and a step of exposing the substrate (100) to plasma formed using a gas containing one or more elements of hydrogen and nitrogen to crystallize the aluminum nitride amorphous thin film (220) to form an aluminum nitride single crystal thin film (200).

[0044] Injecting an aluminum-containing source gas toward the substrate (100) may mean exposing the substrate (100) to the aluminum-containing source gas. Additionally, injecting a nitrogen-containing reactant gas toward the substrate (100) may mean exposing the substrate (100) to the nitrogen-containing reactant gas.

[0045] Plasma can be formed using a gas containing one or more of the elements hydrogen and nitrogen. In other words, plasma can be formed using a gas containing one or more of the elements hydrogen and nitrogen. In other words, plasma can be formed using a gas containing one or more of the elements hydrogen and nitrogen.

[0046] The hydrogen-containing gas may contain one or more of hydrogen (H2) gas and methane (CH4) gas. In other words, the hydrogen-containing gas may contain one or more of hydrogen (H2) and methane (CH4). The nitrogen-containing gas may contain one or more of nitrous oxide (N2O) gas and nitrogen monoxide (NO) gas. In other words, the nitrogen-containing gas may contain one or more of nitrous oxide (N2O) and nitrogen monoxide (NO).

[0047] A plasma formed using a hydrogen-containing gas may be referred to as a hydrogen plasma or a hydrogen-containing plasma, and a plasma formed using a nitrogen-containing gas may be referred to as a nitrogen plasma or a nitrogen-containing plasma. Furthermore, a plasma formed using gases containing hydrogen and nitrogen may be referred to as a hydrogen and nitrogen-containing plasma. Furthermore, an "aluminum-containing source gas" may be referred to as an "aluminum-containing gas," and a "nitrogen-containing reactant gas" may be referred to as a "nitrogen-containing gas."

[0048] The method for forming an aluminum nitride single crystal thin film (200) is a process cycle (CY) for forming an aluminum nitride single crystal thin film. AlN ) can be included. And one process cycle (CY AlN ) may include 'aluminum-containing source gas injection step - nitrogen-containing reactant gas injection step - plasma formation step'.

[0049] Additionally, one process cycle (CY) AlN ) may include a purge step, i.e. one process cycle (CY AlN) may further include at least one of a purge step (first purge step) performed between the aluminum-containing source gas injection step and the nitrogen-containing reactant gas injection step and a purge step (second purge step) performed between the nitrogen-containing reactant gas injection step and the plasma formation step. Here, the purge step may mean supplying a purge gas into the interior of a chamber in which a substrate (100) is loaded and exhausting the purge gas through an exhaust port installed in the chamber.

[0050] 1 process cycle (CY) AlN ) includes a purge step, it can be performed in the order of 'aluminum-containing source gas injection step - 1st purge step - nitrogen-containing reactant gas injection step - 2nd purge step - plasma formation step'. At this time, the process cycle (CY AlN ) at least one of the first and second fuzzy steps may be omitted.

[0051] Additionally, one process cycle (CY) AlN ) may further include a step of generating plasma between the aluminum-containing source gas injection step and the nitrogen-containing reactant gas injection step or between the aluminum-containing source gas injection step and the first purge step. That is, one process cycle (CY) AlN ) may further include a 'plasma forming step' performed after the aluminum-containing source gas injection is terminated and before the nitrogen-containing reactant gas injection is performed.

[0052] That is, one process cycle (CY) AlN) may include 'aluminum-containing source gas injection step - nitrogen-containing reactant gas injection step - plasma formation step', or 'aluminum-containing source gas injection step - plasma formation step - nitrogen-containing reactant gas injection step - plasma formation step', or 'aluminum-containing source gas injection step - first purge step - nitrogen-containing reactant gas injection step - second purge step - plasma formation step', or 'aluminum-containing source gas injection step - plasma formation step - first purge step - nitrogen-containing reactant gas injection step - second purge step - plasma formation step'. And, in the above-described plasma formation step, it may be formed using a gas containing one or more of hydrogen and nitrogen.

[0053] And, the process cycle (CY) as described above AlN ) can be performed n times (n: 1, 2, 3, …). That is, the method for forming an aluminum nitride single crystal thin film (200) can be performed once (n=1) or twice or more (n ≥ 2) process cycles (CY AlN ) may be included. Here, 2 or more times may mean multiple times.

[0054] In the embodiment, a process cycle (CY) including 'aluminum-containing source gas injection step - nitrogen-containing reactant gas injection step - plasma formation step' as described above AlN ) is performed once or multiple times to form an aluminum nitride single crystal thin film (200). Accordingly, the method for forming the aluminum nitride single crystal thin film (200) can be described as an atomic layer deposition (ALD) method. More specifically, in the embodiment, the aluminum nitride single crystal thin film (200) is formed by an atomic layer deposition (ALD) method that forms plasma after injecting a nitrogen-containing reactant.

[0055] In this way, in the embodiment, after injecting a nitrogen-containing reactant gas, plasma is formed to crystallize the aluminum nitride amorphous thin film (220). That is, the aluminum nitride amorphous thin film (220) is crystallized using plasma formed using a gas containing one or more of hydrogen and nitrogen. Accordingly, the aluminum nitride amorphous thin film (220) can be crystallized at a low temperature of 600°C or less without heating the substrate (100) or the interior of the chamber to a high temperature, for example, a temperature exceeding 600°C, more specifically, 1000°C or more. More specifically, even if the substrate (100) or the interior of the chamber is heated to a low temperature of 200°C to 600°C, the aluminum nitride amorphous thin film (220) can be sufficiently crystallized using plasma. In other words, even if the substrate (100) is heated to a low temperature of 200°C to 600°C, a single-crystal amorphous aluminum nitride thin film (220) can be formed.

[0056] In addition, even if it is formed with a thinner thickness than before, the aluminum nitride thin film can be crystallized. That is, even if the aluminum nitride amorphous thin film (220) is formed with a thin thickness of 200 Å or less (10 Å or more), the aluminum nitride amorphous thin film (220) can be crystallized using plasma. In other words, the aluminum nitride single crystal thin film (200) can be formed with a thin thickness of 10 Å or more and 200 Å or less.

[0057]

[0058] Meanwhile, if the substrate or the interior of the chamber is heated to less than 200°C, crystallization of the amorphous aluminum nitride thin film may be difficult. That is, if the substrate or the interior of the chamber is heated to less than 200°C, formation of an aluminum nitride single crystal thin film may be difficult. In addition, if the substrate or the interior of the chamber is heated to more than 600°C, the lower film (110) may be damaged by the high temperature, resulting in defects. In addition, there is a problem that power consumption increases in order to heat the substrate or the interior of the chamber to more than 600°C.

[0059] Therefore, in the embodiment, the temperature of the substrate (100) or the chamber is heated to a temperature of 200°C to 600°C.

[0060]

[0061] FIG. 3 is a schematic drawing of a first type of substrate processing apparatus capable of forming an aluminum nitride single crystal thin film using a method according to an embodiment of the present invention. FIG. 4 is a schematic perspective view illustrating a substrate support portion of the first type of substrate processing apparatus illustrated in FIG. 3. FIG. 5 is a side cross-sectional view illustrating a gas injection portion of the first type of substrate processing apparatus illustrated in FIG. 3. FIG. 6 is a schematic bottom view of the gas injection portion of the first type of substrate processing apparatus illustrated in FIG. 3.

[0062] Hereinafter, with reference to FIGS. 3 to 6, a first type of substrate processing device capable of forming an aluminum nitride single crystal thin film (200) using a method according to an embodiment of the present invention will be described.

[0063] Referring to Fig. 3, the first type of substrate processing device (1) performs a processing process on a substrate (100). The first type of substrate processing device (1) can perform a deposition process for depositing a thin film on the substrate (100), an etching process for removing a portion of the thin film deposited on the substrate (100), etc.

[0064] Hereinafter, an example in which a first type substrate processing device (1) performs the deposition process will be described, but it will be obvious to those skilled in the art to which the present invention pertains to derive an example in which a first type substrate processing device (1) according to the present invention performs other processing processes, such as the etching process.

[0065] A first type substrate processing device (1) may include a chamber (2), a substrate support member (3), and a gas injection member (4). In addition, the first type substrate processing device (1) may include a heater (not shown) that heats the interior of the chamber (2). In this case, the heater may be connected to the chamber (2) or installed inside the chamber (2).

[0066] Referring to FIG. 3, the chamber (2) provides an internal space in which a thin film can be deposited on a substrate (100) or the substrate can be etched. Hereinafter, the internal space of the chamber (2) is referred to as a process space (SP). In the process space (SP), a processing process such as a deposition process or an etching process for the substrate (100) can be performed. The process space (SP) can be arranged inside the chamber (2). An exhaust port (not shown) for exhausting gas from the process space (SP) can be coupled to the chamber (2). The substrate support (3) and the gas injection unit (4) can be installed in the chamber (2), and the substrate support (3) and the gas injection unit (4) can be installed so as to be located inside the chamber (2).

[0067] Referring to Fig. 3, the substrate support (3) supports the substrate (100). That is, the substrate (100) loaded into the chamber (2) is placed on the substrate support (3). The substrate support (3) can support a plurality of substrates (100), for example, six substrates (100). Accordingly, the first type of substrate processing device (1) can perform a processing process on a plurality of substrates (100) at a time. Accordingly, when a product is produced by depositing a thin film or performing etching on a substrate (100) using the first type of substrate processing device (1), there is an effect of improving productivity.

[0068] The above substrate support member (3) can be coupled to the chamber (2). The above substrate support member (3) can be placed inside the chamber (2).

[0069] Referring to Fig. 4, the substrate support (3) may include a support surface (31). The support surface (31) may be a surface of the substrate support (3) arranged to face the gas injection unit (4). When the substrate support (3) is arranged below the gas injection unit (4), the support surface (31) may correspond to an upper surface of the substrate support (3). The substrates (100) may be supported on the support surface (31).

[0070] The substrate support member (3) can support the substrates (100) in an outer region (33) disposed outside the central region (32). The outer region (33) can be disposed to surround the central region (32). Accordingly, the central region (32) can be disposed inside the outer region (33). When the central region (32) is formed in a circular shape, the outer region (33) can be formed in a circular ring shape surrounding the central region (32). The substrates (100) can be disposed to be spaced apart from each other along the outer region (33). In this case, the substrates (100) can be supported on the support surface (31) so as to be spaced apart from each other at the same angle with respect to the central axis (30) of the substrate support member (3) in the outer region (33). When the substrate support member (3) is rotated while the above processing is performed, the substrate support member (3) can be rotated around the central axis (30). When the support surface (31) is formed in a circular shape, the central axis (30) can correspond to the center of the support surface (31). Meanwhile, since the substrates (100) are supported by the support surface (31) in the outer region (33), the substrates (100) may not be positioned in the central region (32).

[0071] In the above, it has been described that the substrate support member (3) supports six substrates. However, this is not limited to this, and the substrate support member (3) may support a variety of substrates (100) in numbers of two or more. In addition, the substrate support member (3) may also support one substrate (100).

[0072] The gas supply unit (40) stores gas and supplies the gas to the gas injection unit (4). That is, the gas supply unit (40) stores gas for forming an aluminum nitride single crystal thin film (200) according to an embodiment of the present invention and supplies the gas to the gas injection unit (4).

[0073]

[0074] In Fig. 3, one gas supply unit (40) is illustrated, but a plurality of gas supply units may be provided. The gas supply unit (40) may include a plurality of gas supply units that supply different types of gases to the gas injection unit (4). That is, the gas supply unit (40) may include a source gas supply unit that supplies a source gas to the gas injection unit (4), a reactant gas supply unit that supplies a reactant gas to the gas injection unit (4), and a gas supply unit (hereinafter, plasma gas supply unit) that can supply a gas for forming plasma. In addition, the gas supply unit (40) may further include a discharge gas supply unit that supplies a discharge gas (hereinafter, discharge gas) and a purge gas supply unit that supplies a purge gas.

[0075] The gas supplied from the source gas supply unit may be an aluminum (Al)-containing source gas. More specifically, the aluminum-containing source gas may be a gas containing trimethyl aluminum (TMA). Of course, the aluminum-containing source gas is not limited to the materials described above, and various gases containing aluminum (Al) may be used.

[0076] The gas supplied from the reactant gas supply unit may be a nitrogen (N)-containing reactant gas. More specifically, the nitrogen-containing reactant gas may be, for example, nitrogen (N) gas or a gas containing NH3. Of course, the nitrogen-containing reactant gas is not limited to the materials described above, and various gases containing nitrogen (N) may be used.

[0077] The plasma gas supply unit may be a gas containing one or more of hydrogen (H) and nitrogen (N). More specifically, the plasma gas supply unit may supply a gas containing one or more of hydrogen (H2), methane (CH4), nitrous oxide (N2O), and nitrogen monoxide (NO) into the interior of the chamber. The gas supplied from the plasma gas supply unit into the interior of the chamber may be referred to as a “plasma forming gas.” That is, the plasma forming gas may contain one or more of hydrogen (H2), methane (CH4), nitrous oxide (N2O), and nitrogen monoxide (NO).

[0078] In addition, the discharge gas and purge gas supplied from the discharge gas supply unit and the purge gas supply unit may be argon (Ar) gas.

[0079] Referring to Fig. 3, the gas injection unit (4) injects gas toward the substrate support unit (3). The gas injection unit (4) may be connected to a gas supply unit (40). Accordingly, the gas injection unit (4) may inject gas supplied from the gas supply unit (40) toward the substrate support unit (3). The gas injection unit (4) may be coupled to the chamber (2) and installed to be located inside the chamber (2). The gas injection unit (4) may be arranged to face the substrate support unit (3). The process space (SP) may be arranged between the gas injection unit (4) and the substrate support unit (3). The gas injection unit (4) may also be coupled to a lid. The lid is coupled to the chamber (2) to cover the upper portion of the chamber (2).

[0080] The above gas injection unit (4) may include a first gas path (41) and a second gas path (42).

[0081] The first gas path (41) is for injecting the first gas. One side of the first gas path (41) may be connected to the gas supply unit (40) via a pipe, hose, or the like. The other side of the first gas path (41) may be connected to the process space (SP). Accordingly, the first gas supplied from the gas supply unit (40) may flow along the first gas path (41) and then be injected into the process space (SP) through the first gas path (41). The first gas path (41) may function as a passage for the first gas to flow and also as an injection port for injecting the first gas into the process space (SP).

[0082] The second gas path (42) is for injecting the second gas. The second gas and the first gas may be different gases. For example, when the first gas is an aluminum-containing source gas, the second gas may be a nitrogen-containing reactant gas. That is, the aluminum-containing source gas may pass through the first gas path (41), and the nitrogen-containing reactant gas may pass through the second gas path (42). Of course, the opposite is also possible. That is, the nitrogen-containing source gas may pass through the first gas path (41), and the aluminum-containing reactant gas may pass through the second gas path (42). As another example, the first gas may be a plasma-forming gas and a discharge gas, and the second gas may be a purge gas. That is, the plasma-forming gas and the discharge gas may pass through the first gas path (41), and the purge gas may pass through the second gas path (42). Of course, the opposite case is also possible. That is, the purge gas can pass through the first gas path (41), and the plasma forming gas and discharge gas can pass through the second gas path (42).

[0083] The second gas path (42) is for injecting the second gas. The second gas and the first gas may be different gases. For example, when the first gas is an aluminum-containing source gas, the second gas may be a nitrogen-containing reactant gas. That is, the aluminum-containing source gas may pass through the first gas path (41), and the nitrogen-containing reactant gas may pass through the second gas path (42). Of course, the opposite is also possible. That is, the nitrogen-containing source gas may pass through the first gas path (41), and the aluminum-containing reactant gas may pass through the second gas path (42). As another example, the first gas may be a plasma-forming gas, and the second gas may be a discharge gas. That is, the plasma-forming gas may pass through the first gas path (41), and the discharge gas may pass through the second gas path (42). Of course, the opposite is also possible. That is, the discharge-containing gas can pass through the first gas path (41), and the plasma-forming gas can pass through the second gas path (42).

[0084] The second gas path (42) may have one end connected to the gas supply unit (40) via a pipe, hose, or the like. The other end of the second gas path (42) may be connected to the process space (SP). Accordingly, the second gas supplied from the gas supply unit (40) may flow along the second gas path (42) and then be injected into the process space (SP) through the second gas path (42). The second gas path (42) may function as a passage for the second gas to flow and also as an injection port for injecting the second gas into the process space (SP).

[0085] The second gas path (42) and the first gas path (41) may be arranged to be spatially separated from each other. Accordingly, the second gas supplied from the gas supply unit (40) to the second gas path (42) can be injected into the process space (SP) without passing through the first gas path (41). The first gas supplied from the gas supply unit (40) to the first gas path (41) can be injected into the process space (SP) without passing through the second gas path (42). The second gas path (42) and the first gas path (41) can inject gases toward different parts of the process space (SP).

[0086] Referring to Fig. 5, the gas injection unit (4) may include a first electrode (43) and a second electrode (44). The first electrode (43) may be disposed on the upper side of the substrate support member (3) so as to face the substrate support member (3). The first electrode (43) may be grounded, thereby functioning as a ground electrode. The first electrode (43) may include the first gas passage (41) and the second gas passage (42). Accordingly, the first electrode (43) may inject the first gas through the first gas passage (41) and the second gas through the second gas passage (42). The first gas path (41) and the second gas path (42) can be arranged to be spatially separated from each other inside the first electrode (43).

[0087] The first gas path (41) may include a first connection hole (411) connected to the gas supply unit (40) and a plurality of first injection holes (412) connected to the first connection hole (411). The first connection hole (411) and the first injection holes (412) may be formed inside the first electrode (43). One side of the first injection holes (412) may be connected to the first connection hole (411), and the other side may be connected to the process space (SP). Accordingly, the first gas supplied by the gas supply unit (40) may flow along the first connection hole (411) and then be injected into the process space (SP) through the first injection holes (412).

[0088] The second gas path (42) may include a second connection hole (421) connected to the gas supply unit (40) and a plurality of second injection holes (422) connected to the second connection hole (421). The second connection hole (421) and the second injection holes (422) may be formed inside the first electrode (43). One side of the second injection holes (422) may be connected to the second connection hole (421), and the other side may be connected to the process space (SP). Accordingly, the second gas supplied by the gas supply unit (40) may flow along the second connection hole (421) and then be injected into the process space (SP) through the second injection holes (422). That is, the second injection hole (422) of the second gas path (42) formed in the first electrode (43) injects gas toward the upper portion of the second electrode (44).

[0089] The first electrode (43) may include a base electrode (43a) extending in the direction in which the substrate support member (3) extends, and a protruding electrode (43b) extending downwardly from the lower surface of the base electrode (43a). The protruding electrode (43b) may have a shape extending from the lower surface of the base electrode (43a) in the direction in which the substrate support member (3) is positioned. A plurality of such protruding electrodes (43b) may be provided, and the plurality of protruding electrodes (43b) may be arranged to be spaced apart from each other.

[0090] When the first electrode (43) includes a base electrode (43a) and a protruding electrode (43b), each of the first connecting hole (411), the second connecting hole (421), and the second injection hole (422) may be provided in the base electrode (43a). At this time, the first and second connecting holes (411, 421) may have a shape extending in the direction in which the base electrode (43a) extends, for example. In addition, the second injection hole (422) may extend in the vertical direction, one end may be connected to the second connecting hole (421), and the other end may be connected to the process space (SP). In addition, the first injection hole (412) of the first gas path (41) may be provided to extend from the base electrode (43a) to the protruding electrode (43b). That is, the first injection hole (412) can be formed by vertically penetrating the protruding electrode (43b), and one end in the extension direction can be connected to the first connection hole (411) and the other end can be connected to the process space (SP). In other words, the first injection hole of the first gas path (41) is formed inside the protruding electrode (43b). Since the first connection hole (411) is formed in the base electrode (43a), the first injection hole (412) can be vertically penetrating a part of the base electrode (43a) and connected to the first connection hole (411).

[0091] The second electrode (44) may include a hole (44a) into which a protruding electrode (43b) may be inserted. The hole (44a) may be formed by penetrating the second electrode (44). This hole (44a) may function as a passage for passing gas discharged from the first electrode (43). The number of holes (44a) may be the same as that of the protruding electrodes (43b), and the holes (44a) may be formed at positions facing the protruding electrodes (43b). In addition, a protruding electrode (43b) may be inserted into each of a plurality of holes (44a). That is, the protruding electrode (43b) penetrates the hole (44a) formed in the second electrode (44). The inner diameter (or width) of the hole (44a) is larger than the diameter (or width) of the protruding electrode (43b), and the vertical length of the hole (44a) may be smaller than the vertical length of the protruding electrode (43b).

[0092] When the protruding electrode (43b) of the first electrode (43) is inserted into the hole (44a) formed in the second electrode (44), the height of the lower surface of the protruding electrode (43b) is the same as the height of the lower surface of the second electrode (44). Accordingly, the lower surface of the base electrode (43a) and the upper surface of the second electrode (44) are spaced apart from each other, and the spaced space is communicated with the second injection hole (422). That is, the second electrode (44) is separately disposed below the first electrode (43).

[0093] In addition, when the protruding electrode (43b) of the first electrode (43) is inserted into the hole (44a) of the second electrode (44), the outer surface of the protruding electrode (43b) is inserted so as to be spaced apart from the inner surface of the second electrode (44) surrounding the hole (44a). Accordingly, the outer space of the protruding electrode (43b) in the hole (44a) is communicated with the space between the lower surface of the base electrode (43a) and the upper surface of the second electrode (44). In addition, the outer space of the protruding electrode (43b) in the hole (44a) is communicated with the process space (SP). Therefore, the gas discharged from the second injection hole (422) can pass through the hole (44a) provided in the second electrode (44) and be injected toward the substrate support member (3). That is, the second gas discharged from the second injection hole (422) can pass through the gap between the lower surface of the base electrode (43a) and the upper surface of the second electrode (44), and then pass through the hole (44a) provided in the second electrode (44) and be injected to the lower side of the hole (44a). At this time, when the second gas passes through the hole (44a), it passes along the outer space of the protruding electrode (43b).

[0094] An insulating member (not shown) for partial insulation may be disposed between the second electrode (44) and the first electrode (43). RF power may be applied to the second electrode (44). When the first electrode (43) is grounded and the RF power is applied to the second electrode (44), plasma may be generated. That is, plasma may be generated in the space between the first electrode (43) and the second electrode (44). More specifically, plasma may be generated in the gap between the lower surface of the base electrode (43a) and the upper surface of the second electrode (44) and in the hole (44a). In addition, the plasma thus formed may be used to activate gas, and the activated gas may be injected into the process space (SP).

[0095] In the above, it was described that plasma is formed by grounding the first electrode (43) and applying RF power to the second electrode (44). However, this is not limited to this, and plasma may be formed by applying RF power to the first electrode (43) and grounding the second electrode (44). In addition, plasma may be formed by applying a positive (+) voltage to one of the first electrode (43) and the second electrode (44) and connecting a negative (-) electrode to the other electrode.

[0096] The gas injection unit (4) injects gas toward the substrate support unit (3). At this time, the gas injection unit (4) may be provided so as to inject gas only toward the outer region (33) of the support surface (31) of the substrate support unit (3). In this case, the gas injection unit (4) is provided so as not to inject gas toward the central region (32) of the substrate support unit (3). The gas injection unit (4) may be provided so as not to inject gas toward the central region (32) of the support surface (31) where the substrate (100) is not supported, but only toward the outer region (33) of the support surface (31) where the substrate (100) is supported.

[0097] To this end, as illustrated in FIG. 6, the first injection hole (412) and the hole (44a) can be provided only in the area facing the outer region (33) of the substrate support (3). That is, when the protruding electrode (43b) is connected to the lower surface of the base electrode (43a), the protruding electrode (43b) can be connected only in the area facing the outer region (33) of the substrate support (3) among the lower surfaces of the base electrode (43a). In addition, since the first injection hole (412) is provided by vertically penetrating the protruding electrode (43b), the first injection hole (412) is formed only in the area facing the outer region of the substrate support (3). In addition, when forming a plurality of holes (44a) in the second electrode (44), they are formed only in the area facing the outer region (33) of the substrate support (3), and are formed at a position into which the protruding electrode (43b) can be inserted. Accordingly, a plurality of holes (44a) are formed only in the outer region (33) of the substrate support member (3). Accordingly, the first gas passing through the first injection hole (412) and the second gas or plasma passing through the hole (44a) can be injected only into the outer region of the substrate support member (3).

[0098] Accordingly, the first type substrate processing device (1) can reduce the flow rate of gas that is wasted because the substrate (100) flows to the central region (32) where it is not supported and thus does not participate in the processing process. Accordingly, the first type substrate processing device (1) can reduce operating costs by reducing the flow rate of wasted gas. In addition, when forming an aluminum nitride single crystal thin film (200) using the first type substrate processing device (1), the manufacturing cost required to manufacture the aluminum nitride single crystal thin film (200) can be reduced.

[0099] In addition, the first type of substrate processing device (1) intensively sprays gas toward the outer region (33) where the substrate (100) is supported, so that the flow rate of gas involved in the processing process can be increased by flowing to the outer region (33) where the substrate (100) is supported. Accordingly, the first type of substrate processing device (1) can improve the quality of the substrate (100) on which the processing process is performed.

[0100]

[0101] Hereinafter, with reference to FIGS. 2 to 6, a method for forming an aluminum nitride single crystal thin film (200) using a first type of substrate processing device (1) will be described. At this time, a plurality of substrates (100) are supported on an outer region (33) of a support surface (31) of a substrate support portion (3), and a gas injection portion (4) injects gas only to the outer region (33) of the support surface (31) of the substrate support portion (3). In addition, a case in which a wafer having a diameter of 300 mm is used as a substrate (100) will be described as an example.

[0102] First, a plurality of substrates (100) are loaded into the chamber (2), and then the plurality of substrates (100) are placed on the substrate support member (3). That is, as shown in Fig. 4, the substrates (100) are placed on the outer region (33) of the support surface (31) of the substrate support member (3). Then, the temperature of the substrates (100) is adjusted to 200°C to 600°C using a heater (not shown).

[0103] Next, an aluminum-containing source gas is injected toward the substrate support (3) using the gas injection unit (4). To this end, the aluminum-containing source gas is supplied to the first connection hole (411) of the gas injection unit (4) using the gas supply unit (40). Accordingly, the aluminum-containing source gas supplied to the first connection hole (411) passes through the first injection hole (412) formed in the protruding electrode (43b) and is injected toward the substrate support (3). At this time, the aluminum-containing source gas is injected into the outer region (33) of the support surface (31) of the substrate support (3). Accordingly, the aluminum-containing source gas is adsorbed or deposited on the substrate (100) mounted on the substrate support (3), so that an atomic layer or single layer thin film containing aluminum is formed on the substrate (100). That is, an aluminum-containing thin film (210) is formed as shown in (a) of Fig. 2.

[0104] Afterwards, purge gas is supplied into the chamber (2) to purge the chamber (2) (first purge).

[0105] When the first purge is completed, a nitrogen-containing reactant gas is injected using the gas injection unit (4). To this end, the nitrogen-containing reactant gas is supplied to the second connection hole (421) of the gas injection unit (4) using the gas supply unit (40). Accordingly, the nitrogen-containing reactant gas supplied to the second connection hole (421) passes through the second injection hole (422) and then flows into the gap between the base electrode (43a) and the second electrode (44). That is, the nitrogen-containing reactant gas flows into the gap between the base electrode (43a) and the upper surface of the second electrode (44) and the hole (44a).

[0106] A nitrogen-containing reactant gas is injected into the lower portion of the hole (44a), and at this time, the nitrogen-containing reactant gas is injected into the outer region (33) of the support surface (31) of the substrate support member (3). Accordingly, the nitrogen-containing reactant gas is adsorbed or deposited on the aluminum-containing thin film (210), thereby forming an atomic layer or single layer thin film containing aluminum and nitrogen. At this time, the atomic layer or single layer thin film containing aluminum and nitrogen may be amorphous. That is, an aluminum nitride amorphous thin film (220) is formed as shown in (b) of Fig. 2.

[0107] Afterwards, purge gas is supplied into the chamber (2) to purge the chamber (2) (secondary purge).

[0108] When the secondary purge is completed, plasma is formed. To this end, a plasma forming gas is supplied to the second connection hole (421) of the gas injection unit (4) using the gas supply unit (40). That is, a gas containing one or more of hydrogen and nitrogen is supplied to the second connection hole (421) of the gas injection unit (4). More specifically, a gas containing one or more of hydrogen (H2), methane (CH4), nitrous oxide (N2O), and nitrogen monoxide (NO) is supplied to the second connection hole (421) of the gas injection unit (4). At this time, it is more effective to supply a discharge gas, for example, argon gas, together to the second connection hole (421). Accordingly, the plasma forming gas and the discharge gas supplied to the second connection hole (421) pass through the second injection hole (422) and then flow into the space between the base electrode (43a) and the second electrode (44). That is, the gas for plasma formation and the discharge gas are introduced into the gap space and hole (44a) between the upper surface of the base electrode (43a) and the second electrode (44).

[0109] In this way, while the gas passes through the space between the first electrode (43) and the second electrode (44), RF power is applied to the second electrode (44). At this time, it is preferable to apply power of 2.83 mW to 8.49 mW (2.83 milliwatts to 8.49 milliwatts) per unit area of ​​the substrate (100). In other words, it is preferable to adjust the RF power applied to the second electrode (44) to 200 W to 600 W (200 watts to 600 watts). When power is applied to the second electrode (44), the gas passing through the space between the first electrode (43) and the second electrode (44) is discharged to form plasma. At this time, since the plasma is formed using a plasma-forming gas containing one or more of hydrogen and nitrogen, the plasma may contain one or more of hydrogen and nitrogen elements.

[0110] Meanwhile, when applying power to the second electrode (44), if it is less than 2.83 mW per unit area of ​​the substrate (100), crystallization of the aluminum nitride thin film may be difficult. In addition, when applying power to the second electrode (44), if it exceeds 8.49 mW per unit area of ​​the substrate (100), the underlying film may be damaged by heat.

[0111] In addition, if the RF power applied to the second electrode (44) is less than 200 W, crystallization of the aluminum nitride thin film may be difficult, and if it exceeds 600 W, the lower film may be damaged by heat.

[0112] When plasma is formed, the aluminum nitride amorphous thin film (220) is exposed to the plasma, as shown in (c) of Fig. 2. Then, the bonds between molecules included in the aluminum nitride amorphous thin film (220) are broken. That is, the molecules included in the aluminum nitride amorphous thin film (220) are separated, generating aluminum ions and nitrogen ions. However, at this time, the temperature inside the substrate (100) or chamber (2) is a low temperature of 200°C to 600°C, so it may be difficult for the aluminum ions and nitrogen ions to bond due to the temperature (200°C to 600°C).

[0113] Meanwhile, the aluminum nitride amorphous thin film (220) may contain impurities, and the impurities may include at least one of carbon (C) and oxygen (O). When plasma is formed, as described above, the bonds between molecules are broken, and the impurities included in the aluminum nitride amorphous thin film (220) may be vaporized or gasified and separated from the aluminum nitride amorphous thin film (220). Accordingly, impurities including at least one of carbon (C) and oxygen (O) may be removed from the aluminum nitride amorphous thin film (220).

[0114] When impurities are removed from the aluminum nitride amorphous thin film (220) in this way, a certain amount of energy is generated, and aluminum ions and nitrogen ions can be combined by this energy. As the aluminum ions and nitrogen ions combine, the aluminum nitride amorphous thin film (220) is crystallized. As a result, a crystalline atomic layer or single layer thin film containing aluminum and nitrogen can be formed. That is, as shown in (d) of FIG. 2, a crystalline aluminum nitride thin film (200) or an aluminum nitride single crystal thin film (200) can be formed.

[0115] Meanwhile, conventionally, in order to crystallize an amorphous aluminum nitride thin film (220) or to form an aluminum nitride single crystal thin film (200), the temperature inside the substrate (100) or the chamber (2) was heated to a high temperature of 1000°C or higher, more specifically, to a temperature exceeding 600°C. However, when an aluminum nitride single crystal thin film (200) is formed under the condition that the temperature of the substrate (100) is a high temperature exceeding 600°C, the lower film (110) formed under the aluminum nitride single crystal thin film (200) may be damaged. That is, the lower film (110) may be damaged by the heat of the substrate (100) or the chamber (2) heated to a temperature exceeding 600°C for forming the aluminum nitride single crystal thin film (200), and thus, a problem may arise in which a defect occurs in the lower film (110).

[0116] On the other hand, in the embodiment of the present invention, since plasma is formed after injecting a nitrogen-containing reactant gas, there is no need to heat the temperature inside the substrate (100) or the chamber (2) to a high temperature. That is, even when the temperature inside the substrate (100) or the chamber (2) is controlled to a low temperature of 200°C to 600°C (200°C or higher and 600°C or lower), rather than being controlled to a high temperature exceeding 600°C, the aluminum nitride amorphous thin film (220) can be crystallized. That is, even when the temperature inside the substrate (100) or the chamber (2) is controlled to a low temperature of 200°C to 600°C, the aluminum nitride single crystal thin film (200) can be formed. Accordingly, the lower film (110) formed under the aluminum nitride single crystal thin film (200) can be suppressed or prevented from being damaged by heat.

[0117] Process Cycle (CY) AlN ) may include the 'aluminum-containing source gas injection step, first purge step, nitrogen-containing reactant gas injection step, second purge step, and plasma formation step' as described above. And, the process cycle (CY AlN) can be performed once or twice or more to form an aluminum nitride single crystal thin film (200) with a target thickness.

[0118] At this time, the aluminum nitride single crystal thin film (200) can be formed with a thin thickness of 200 Å or less (10 Å or more). In the embodiment, by forming plasma after injecting the nitrogen-containing reactant gas as described above, the aluminum nitride single crystal thin film can be formed even with a thin thickness of 200 Å or less (10 Å or more). That is, even if the aluminum nitride amorphous thin film (220) is formed with a thin thickness of 200 Å or less (10 Å or more), the aluminum nitride amorphous thin film (220) can be crystallized.

[0119] Of course, the aluminum nitride single crystal thin film (200) can also be formed with a thickness exceeding 200 Å.

[0120]

[0121] In the above, it has been described that the nitrogen-containing reactant gas is injected after the aluminum-containing source gas injection and the first purge are completed. However, this is not limited thereto, and plasma may be formed after the aluminum-containing source gas injection and the first purge are completed and before the nitrogen-containing reactant gas is injected. The plasma formed before the nitrogen-containing reactant gas is injected can remove impurities contained in the aluminum-containing thin film (210), thereby improving the thin film properties or electrical properties of the aluminum nitride single crystal thin film (200).

[0122]

[0123] FIG. 7 is a schematic bottom view of a gas injection unit according to a modified example in the first type of substrate processing device illustrated in FIG. 3.

[0124] In the above, it has been described that the gas injection unit (4) is provided so as to be able to inject gas only to the outer region of the substrate support unit (3). However, the present invention is not limited thereto, and the gas injection unit (4) may be provided so as to be able to inject gas to both the central region (32) and the outer region (33) of the substrate support unit (3). That is, the gas injection unit (4) may be provided so as to be able to inject gas to the entire support surface (31) of the substrate support unit (3). To this end, as illustrated in FIG. 7, the first injection hole (412) may be provided so as to face the central region (32) and the outer region (33) of the substrate support unit (3), and the hole (44a) may be provided so as to face the central region (32) and the outer region (33) of the substrate support unit (3).

[0125]

[0126] FIG. 8 is a schematic drawing of a second type of substrate processing device capable of forming an aluminum nitride single crystal thin film using a method according to an embodiment of the present invention.

[0127] The substrate processing device capable of forming an aluminum nitride single crystal thin film (200) is not limited to the first type of substrate processing device illustrated in FIGS. 3 to 7. The aluminum nitride single crystal thin film may also be formed using the second type of substrate processing device illustrated in FIG. 8.

[0128] Below, the second substrate processing device illustrated in Fig. 8 will be described.

[0129] Referring to FIG. 8, the substrate processing device may include a chamber (1000), a substrate support unit (2000) installed within the chamber (1000) to support a substrate (100), first and second gas injection units (3000a, 3000b) installed within the chamber (1000) so as to face the substrate support unit (2000), a gas supply unit (4000) for providing a process gas to the first and second gas injection units (3000a, 3000b), an antenna (6100) having a coil for inducing an electric field within the chamber (1000) for plasma generation, and a power supply unit (6200) connected to the antenna (6100).

[0130] In addition, the substrate processing device may include a heating unit (5000) installed to face the substrate support unit (2000), a driving unit (7000) that raises and lowers or rotates the substrate support unit (2000), and an exhaust unit (8000) that exhausts gas and impurities inside the chamber (1000).

[0131] In addition, the substrate processing device may include a pump connecting the exhaust section (8000) and the chamber (1000), and the pump may be, for example, a turbomolecular pump (TMP). The turbomolecular pump can maintain a base vacuum inside the chamber (1000), and can form and process a stable plasma at an ultra-low vacuum pressure of several Torr or less even during the process.

[0132] The chamber (1000) may be a cylinder shape having an internal space, and may be, for example, a dome shape as illustrated in FIG. 8. More specifically, the chamber (1000) may include a chamber body (1100), an upper body (1200) installed on the upper side of the chamber body (1100), and a lower body (1300) installed on the lower side of the chamber body (1100). The chamber body (1100) may be a cylinder shape with an upper and a lower side open, and the upper body (1200) may be installed to cover the upper opening of the chamber body (1100), and the lower body (1300) may be installed to cover the lower opening of the chamber body (1100). In addition, the upper body (1200) may be a dome shape having a sloped surface whose height increases toward the center in the width direction thereof. In addition, the lower body (1300) may have a dome shape with a slope whose height decreases toward the center in the width direction. Each of the chamber (1000), i.e., the chamber body (1100), the upper body (1200), and the lower body (1300), may be made of a transparent material that allows light to pass through, for example, quartz. The internal space of the chamber (10000) may be referred to as a process space.

[0133] The gas supply unit (4000) may include a source gas supply unit (4100) for supplying a source gas, a reactant gas supply unit (4200) for supplying a reactant gas, a plasma gas supply unit (4300) for supplying a gas for forming a plasma, and a discharge gas supply unit (4400) for supplying a discharge gas. In addition, the gas supply unit (4000) may further include a purge gas supply unit (not shown) for supplying a purge gas.

[0134] In addition, the gas supply unit (4000) may include a first transport pipe (4500a) connecting the source gas supply unit (4100), the reactant gas supply unit (4200) and the first gas injection unit (3000a), and a second transport pipe (4500b) connecting the plasma gas supply unit (4300) and the discharge gas supply unit (4400) and the second gas injection unit (3000b).

[0135] In addition, the gas supply unit (4000) may include a plurality of first connection pipes (4600a) connecting the source gas supply unit (4100), the reactant gas supply unit (4200) and the first transport pipe (4500a), a valve installed in each of the plurality of first connection pipes (4600a), a plurality of second connection pipes (4600b) connecting the plasma gas supply unit (4300) and the discharge gas supply unit (4400) and the second transport pipe (4500b), and a valve installed in each of the plurality of second connection pipes (4600b).

[0136] Hereinafter, with reference to (a) to (d) of FIG. 2 and FIG. 8, a method for forming an aluminum nitride single crystal thin film (200) on a substrate using a second type of substrate processing device will be described. Here, forming an aluminum nitride single crystal thin film (200) on a lower film (110) formed on a substrate (100) will be described as an example.

[0137] First, a plurality of substrates (100) are loaded into the chamber (1000), and then the plurality of substrates (100) are placed on the substrate support member (2000). Then, the temperature of the substrates (100) or the inside of the chamber (1000) is adjusted to 200°C to 600°C using the heating member (5000).

[0138] Next, the aluminum-containing source gas is injected toward the substrate support (2000) using the first gas injection unit (3000a). That is, when the aluminum-containing source gas of the source gas supply unit (4100) is supplied to the first gas injection unit (3000a) using the first conveying pipe (4500a), the first gas injection unit (3000a) injects the aluminum-containing source gas toward the substrate (100). Accordingly, the aluminum-containing source gas is adsorbed or deposited on the substrate (100) mounted on the substrate support unit (2000), thereby forming an atomic layer or single layer thin film containing aluminum. That is, an aluminum-containing thin film (210) is formed as shown in (a) of Fig. 2.

[0139] Thereafter, the chamber (1000) is purged by supplying purge gas into the interior of the chamber (1000) (first purge). At this time, the purge can be performed by injecting the purge gas into the interior of the chamber (1000) using at least one of the first gas injection unit (3000a) or the second gas injection unit (3000b).

[0140] When the first purge is completed, a nitrogen-containing reactant gas is injected using the first gas injection unit (3000a). To this end, the nitrogen-containing reactant gas is supplied to the first gas injection unit (3000a) using the reactant gas supply unit (4200) and the first conveying pipe (4500a). Accordingly, the nitrogen-containing reactant gas is injected into the interior of the chamber (1000) through the first gas injection unit (3000a). Accordingly, the nitrogen-containing reactant gas may be adsorbed or deposited on the aluminum-containing thin film (210), thereby forming an atomic layer or single layer thin film containing aluminum and nitrogen. At this time, the atomic layer or single layer thin film containing aluminum and nitrogen may be amorphous. That is, an aluminum nitride amorphous thin film (220) is formed as shown in (b) of FIG. 2.

[0141] Afterwards, purge gas is supplied into the chamber (2) to purge the chamber (2) (secondary purge).

[0142] When the secondary purge is completed, plasma is formed. To this end, a plasma forming gas is supplied to the second gas injection unit (3000b) using the plasma gas supply unit (4300) and the second transfer pipe (4500b). That is, a plasma forming gas containing one or more of hydrogen and nitrogen is supplied to the second gas injection unit (3000b). More specifically, a gas containing one or more of hydrogen, methane (CH4), nitrous oxide (N2O), and nitrogen monoxide (NO) is supplied to the second gas injection unit (3000b). In addition, it may be preferable to supply a discharge gas together to the second gas injection unit (3000b) using the discharge gas supply unit (4400) and the second transfer pipe (4500b). Accordingly, the plasma forming gas and the discharge gas are injected into the chamber (1000) through the second gas injection unit (3000b).

[0143] In addition, power is applied to the antenna (6100) using the power supply (6200). When applying power to the antenna (6100), it is preferable to apply power of 2.83 mW to 8.49 mW per unit area of ​​the substrate (100). In other words, it is preferable to adjust the RF power applied to the antenna (1600) to 200 W to 600 W. Accordingly, gas is discharged inside the chamber to form plasma. That is, plasma containing one or more elements of hydrogen and nitrogen may be formed. When plasma is formed, the aluminum nitride amorphous thin film (220) may be exposed to the plasma, as shown in (c) of FIG. 2. Then, the bonds of molecules included in the aluminum nitride amorphous thin film (220) are broken. That is, molecules included in the aluminum nitride amorphous thin film (220) are separated to generate aluminum ions and nitrogen ions. In addition, when the aluminum nitride amorphous thin film (220) is exposed to plasma, impurities included in the aluminum nitride amorphous thin film (220) can be vaporized or gasified and separated from the aluminum nitride amorphous thin film (220). That is, impurities including at least one of carbon (C) and oxygen (O) can be removed from the aluminum nitride amorphous thin film (220).

[0144] When impurities are removed from the aluminum nitride amorphous thin film (220) in this way, a certain amount of energy is generated, and aluminum ions and nitrogen ions can be combined by this energy. As the aluminum ions and nitrogen ions combine, the aluminum nitride amorphous thin film (220) is crystallized. That is, a crystalline atomic layer or single layer thin film containing aluminum and nitrogen can be formed. In other words, a crystalline aluminum nitride thin film (200) or an aluminum nitride single crystal thin film (200) can be formed, as shown in (d) of FIG. 2.

[0145] Meanwhile, when applying power to the antenna (1600), if it is less than 2.83 mW per unit area of ​​the substrate (100), crystallization of the aluminum nitride thin film may be difficult. In addition, when applying power to the antenna (1600), if it exceeds 8.49 mW per unit area of ​​the substrate (100), the underlying film may be damaged by heat.

[0146] In addition, if the RF power applied to the antenna (1600) is less than 200 W, crystallization of the aluminum nitride thin film may be difficult, and if it exceeds 600 W, the lower film may be damaged by heat.

[0147] In this way, by forming plasma after injecting a nitrogen-containing reactant gas, there is no need to heat the temperature inside the substrate (100) or the chamber (1000) to a high temperature. That is, by forming a plasma containing one or more of hydrogen and nitrogen, impurities containing at least one of carbon (C) and oxygen (O) contained in the aluminum nitride amorphous thin film (220) can be removed, and aluminum ions and nitrogen ions can be combined by the energy generated when the impurities are removed. Therefore, the aluminum nitride amorphous thin film (220) can be crystallized, and the aluminum nitride single crystal thin film (200) can be formed. That is, by forming a plasma containing one or more of hydrogen and nitrogen, the amorphous thin film can be crystallized even at a low temperature (200°C to 600°C), and the aluminum nitride single crystal thin film (200) can be formed. Accordingly, it is possible to suppress or prevent the lower film (110) formed at the bottom of the aluminum nitride single crystal thin film (200) from being damaged by heat.

[0148] Process Cycle (CY) AlN ) may include the 'aluminum-containing source gas injection step, first purge step, nitrogen-containing reactant gas injection step, second purge step, and plasma formation step' as described above. And, the process cycle (CYAlN ) can be performed once or twice or more to form an aluminum nitride single crystal thin film (200) with a target thickness.

[0149] At this time, the aluminum nitride single crystal thin film (200) can be formed with a thin thickness of 200 Å or less (10 Å or more). In the embodiment, by forming plasma after injecting the nitrogen-containing reactant gas as described above, the aluminum nitride single crystal thin film can be formed even with a thin thickness of 200 Å or less (10 Å or more). That is, even if the aluminum nitride amorphous thin film (220) is formed with a thin thickness of 200 Å or less (10 Å or more), the aluminum nitride amorphous thin film (220) can be crystallized.

[0150] Of course, the aluminum nitride single crystal thin film (200) can also be formed with a thickness exceeding 200 Å.

[0151]

[0152] FIG. 9 is a drawing showing a state in which an upper film is formed on an aluminum nitride single crystal thin film formed by a method according to an embodiment of the present invention.

[0153] A different type of single crystal thin film can be formed on top of the aluminum nitride single crystal thin film (200) formed by the method according to the embodiment. The upper film (300) can be, for example, an aluminum scandium nitride (AlScN) single crystal thin film.

[0154] Meanwhile, when forming an aluminum scandium nitride (AlScN) thin film directly on the upper surface of a substrate (100) such as a silicon wafer, it is difficult to grow the aluminum scandium nitride thin film into a single crystal. This is because the crystal state of the upper surface of the silicon wafer is not good. In other words, the silicon wafer may be polycrystalline, and thus the crystal direction of the upper surface of the silicon wafer may not be consistent. Therefore, when forming or growing an aluminum scandium nitride (AlScN) thin film directly on the upper surface of a silicon wafer, it is difficult to grow the aluminum scandium nitride thin film into a single crystal. In other words, it is difficult to form an aluminum scandium nitride single crystal thin film.

[0155] However, an aluminum scandium nitride thin film is formed on top of the aluminum nitride single crystal thin film (200) formed by the method according to the embodiment as a lower film. At this time, the aluminum scandium nitride thin film can grow along the crystal of the aluminum nitride single crystal thin film (200) as a lower film. Therefore, the aluminum scandium nitride thin film can be grown as a single crystal. In other words, the aluminum scandium nitride single crystal thin film can be easily formed.

[0156] In the above, the formation of an aluminum scandium nitride single crystal thin film on top of an aluminum nitride single crystal thin film (200) formed by a method according to an embodiment has been described as an example. However, the invention is not limited thereto, and the single crystal thin film formed on top of the aluminum nitride single crystal thin film (200) is not limited to an aluminum scandium nitride single crystal thin film, and various single crystal thin films may be formed.

[0157] In addition, the upper film (300) formed on top of the aluminum nitride single crystal thin film (200) is not limited to a single crystal thin film. That is, a polycrystalline thin film, not a single crystal, may be formed on top of the aluminum nitride single crystal thin film formed by the method according to the embodiment.

[0158]

[0159] According to embodiments of the present invention, an aluminum nitride thin film (200) can be formed into a single crystal at a low temperature. That is, even if the temperature inside the substrate or chamber is heated to a low temperature of 200°C to 600°C (200°C or higher and 600°C or lower), rather than being heated to a high temperature exceeding 600°C, the aluminum nitride thin film can be crystallized. Therefore, when forming an aluminum nitride single crystal thin film (200), it is possible to suppress or prevent damage to the underlying film (110) due to high temperature heat.

[0160] In addition, since the aluminum nitride thin film (200) is formed as a single crystal, it can be easy to form the upper film (300) formed on top of the aluminum nitride thin film (200) as a single crystal.

[0161] According to embodiments of the present invention, an aluminum nitride single crystal thin film can be formed at a low temperature. That is, even if the substrate temperature is controlled to a low temperature, the aluminum nitride thin film can be crystallized. Therefore, when forming an aluminum nitride single crystal thin film, damage to the underlying film due to high temperature can be suppressed or prevented.

Claims

1. A method for forming an aluminum nitride thin film on a substrate supported in a process space inside a chamber, (a) a step of exposing the substrate to an aluminum-containing gas; (b) exposing the substrate to a nitrogen-containing gas to form an atomic layer or monolayer containing aluminum and nitrogen; and (c) a step of exposing the substrate to a nitrogen-containing plasma; A method for forming an aluminum nitride thin film by repeating steps (a) to (c) above multiple times.

2. In claim 1, A method for forming an aluminum nitride thin film, comprising the step of controlling the temperature of the substrate to 200°C to 600°C.

3. In claim 1, In the step of exposing the above substrate to a nitrogen-containing plasma, A method for forming an aluminum nitride thin film by applying power of 2.83 mW to 8.49 mW per unit area of ​​the substrate to the chamber.

4. In claim 1, A method for forming an aluminum nitride thin film, comprising a step of exposing the substrate to a nitrogen-containing plasma between the step of exposing the substrate to an aluminum-containing gas and the step of exposing the substrate to a nitrogen-containing gas.

5. In claim 1 or claim 3, The above nitrogen-containing plasma is a method for forming an aluminum nitride thin film using a gas containing one or more elements of nitrous oxide (N2O) and nitrogen monoxide (NO).

6. A step of loading a substrate having a thin film formed on one side into the interior of a chamber; A method for forming a thin film, comprising the step of forming an aluminum nitride thin film on the thin film by the method described in any one of claims 1 to 4.

7. A step of forming an aluminum nitride thin film on a substrate by the method described in any one of claims 1 to 4; and A method for forming a thin film, comprising: forming an upper film of a different type from the aluminum nitride thin film on top of the aluminum nitride thin film, and crystallizing the upper film in the crystal direction of the aluminum nitride thin film.

8. In claim 7, The above upper film is a method for forming a thin film including an aluminum scandium nitride (AlScN) single crystal thin film.

9. A method for forming an aluminum nitride thin film on a substrate placed in a process space of a chamber using a substrate processing device including a chamber having a dome shape at the upper and lower portions and first and second gas injection units connected to the chamber so as to be able to inject gas into a process space inside the chamber, (a) a step of injecting an aluminum-containing gas into the process space of the chamber using the first gas injection unit to expose the substrate to the aluminum-containing gas; (b) a step of injecting a nitrogen-containing gas into the process space of the chamber using the second gas injection unit to expose the substrate to the nitrogen-containing gas, thereby forming an atomic layer or monolayer containing aluminum and nitrogen; and (c) a step of exposing the substrate to a nitrogen-containing plasma; A method for forming an aluminum nitride thin film by repeating steps (a) to (c) above multiple times.

10. In claim 9, The step (c) of exposing the substrate to a nitrogen-containing plasma is: A step of injecting a nitrogen-containing gas into the process space of the chamber using at least one of the first and second gas injection units; and A method for forming an aluminum nitride thin film, comprising: a step of applying power to an antenna installed in the chamber; 11. In claim 9 or claim 10, A method for forming an aluminum nitride thin film, comprising the step of controlling the temperature of the substrate to 200°C to 600°C.

12. In claim 9 or claim 10, The above nitrogen-containing plasma is a method for forming an aluminum nitride thin film using a nitrogen-containing gas containing one or more elements of nitrous oxide (N2O) and nitrogen monoxide (NO).

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