Method for forming thin film

Abstract

The present invention relates to a method for forming a thin film on a substrate, the method comprising the steps of: preparing a substrate on which one or two or more films among a metal film, a metal oxide film, a silicon nitride (SiN) film, and a silicon oxide (SiO) film are formed; spraying a gallium (Ga)-containing source gas onto the substrate; and spraying a nitrogen (N)-containing reactant gas onto the substrate and forming a gallium nitride (GaN) film on the substrate at a temperature of 300-600°C.

Description

Thin film formation method

[0001] The present invention relates to a thin film forming method for forming a thin film containing gallium.

[0002] Typically, manufacturing solar cells, semiconductor devices, flat panel displays, etc. requires forming a predetermined thin film layer, thin film circuit pattern, or optical pattern on a substrate. To achieve this, substrate processing processes are performed, such as a deposition process that deposits a thin film of a specific material onto the substrate, a photo process that selectively exposes the thin film using a photosensitive material, and an etching process that removes the thin film in the selectively exposed portion to form a pattern. These substrate processing processes are performed by a substrate processing device.

[0003] The above substrate processing device can perform a processing process to form a thin film containing gallium (Ga) on a substrate. Thin films containing gallium have a wide band gap and high electron mobility, making them attractive as materials for achieving high speed, low loss, and high efficiency. These thin films containing gallium can be applied to power semiconductor devices, three-dimensional transistors, and other devices.

[0004] Here, a gallium-containing thin film was conventionally formed on a substrate under a high-temperature environment of 700 degrees Celsius or higher. Therefore, during the process of forming a gallium-containing thin film, there was a high risk of damage to the underlying film, and the film quality of the underlying film deteriorated.

[0005] The present invention has been devised to solve the above-described problem, and to provide a method for forming a thin film that can reduce the risk of damage to the underlying film during the process of forming a thin film containing gallium.

[0006] In order to solve the above-described problem, the present invention may include the following configuration.

[0007] A method for forming a thin film according to the present invention is a method for forming a thin film on a substrate, and may include the steps of: preparing a substrate on which one or more films of a metal film, a metal oxide film, a silicon nitride (SiN) film, and a silicon oxide (SiO) film are formed; injecting a gallium (Ga)-containing source gas onto the substrate; and injecting a nitrogen (N)-containing reactant gas onto the substrate and forming a gallium nitride (GaN) film on the substrate at a temperature of 300 to 600 degrees.

[0008] A method for forming a thin film according to the present invention is a method for forming a thin film on a substrate, and may include the steps of: preparing a substrate on which one or more films of a metal film, a metal oxide film, a silicon nitride (SiN) film, and a silicon oxide (SiO) film are formed at a first process temperature; injecting a gallium (Ga)-containing source gas onto the substrate; and injecting a nitrogen (N)-containing reactant gas onto the substrate. The first process temperature may be 300 degrees to 600 degrees or less.

[0009] According to the present invention, the following effects can be achieved.

[0010] The present invention is implemented to reduce the risk of damage to a film formed on a substrate due to high temperatures during the process of forming a gallium nitride film. Accordingly, the present invention can improve the film quality of the film formed on the substrate, thereby improving the quality of the substrate on which the processing process has been performed.

[0011] Figure 1 is a schematic diagram showing an example of a substrate processing device in which a thin film forming method according to the present invention is performed.

[0012] Figures 2 and 3 are schematic side cross-sectional views of an injection unit that injects gas in an example of a substrate processing device in which a thin film forming method according to the present invention is performed.

[0013] Figure 4 is a schematic cross-sectional view showing an example of a substrate on which a thin film containing gallium is formed by a thin film forming method according to the present invention.

[0014] Figure 5 is a schematic flowchart of a thin film forming method according to the present invention.

[0015] Figures 6 to 8 are schematic cross-sectional views showing another example of a substrate on which a thin film containing gallium is formed by a thin film forming method according to the present invention.

[0016] Figure 9 is a schematic diagram showing a substrate processing device according to the present invention.

[0017] Hereinafter, embodiments of a thin film formation method according to the present invention will be described in detail with reference to the attached drawings. When describing embodiments of the present invention, where it is described that a structure is formed on another structure, such description should be interpreted to include not only cases where the structures are in contact with each other, but also cases where a third structure is interposed between the structures.

[0018] Referring to FIGS. 1 to 5, a method for forming a thin film according to the present invention is for forming a thin film containing gallium on a substrate (100). The substrate (100) may be a silicon substrate, a glass substrate, a metal substrate, or the like. The thin film may be provided in a semiconductor device, a display device, a solar cell, or the like. For example, the thin film may be provided in a power semiconductor device, a three-dimensional transistor, or the like.

[0019] The thin film formation method according to the present invention can be performed by a substrate processing device (1). Before explaining an embodiment of the thin film formation method according to the present invention, an example of the substrate processing device (1) will be specifically examined as follows.

[0020] Referring to FIGS. 1 to 5, the substrate processing device (1) may include a chamber (2), a substrate support unit (3), and an injection unit (4).

[0021] The chamber (2) above provides a processing space (200). A process for forming a thin film can be performed in the processing space (200). The processing space (200) can be arranged inside the chamber (2). An exhaust port (not shown) for exhausting gas from the processing space (200) can be coupled to the chamber (2). The substrate support unit (3) and the injection unit (4) can be arranged inside the chamber (2).

[0022] The substrate support member (3) above supports the substrate (100). The substrate support member (3) may support one substrate (100) or may support multiple substrates (100). When multiple substrates (100) are supported by the substrate support member (3), processing processes for multiple substrates (100) can be performed at once. The substrate support member (3) may be coupled to the chamber (2). The substrate support member (3) may be placed inside the chamber (2).

[0023] The above-described injection unit (4) injects gas toward the substrate support unit (3). The injection unit (4) may be connected to a gas storage unit (40). In this case, the injection unit (4) may inject gas supplied from the gas storage unit (40) toward the substrate support unit (3). The injection unit (4) may be disposed inside the chamber (2). The injection unit (4) may be disposed opposite the substrate support unit (3). The injection unit (4) may be disposed above the substrate support unit (3). The processing space (200) may be disposed between the injection unit (4) and the substrate support unit (3). The injection unit (4) may be coupled to a lid (not shown). The lid may be coupled to the chamber (2) so as to cover the upper portion of the chamber (2).

[0024] The above injection unit (4) may include a first gas path (4a) and a second gas path (4b).

[0025] The first gas path (4a) is for injecting the first gas. One side of the first gas path (4a) may be connected to the gas storage unit (40) via a pipe, hose, gas block, or the like. The other side of the first gas path (4a) may be connected to the processing space (200). Accordingly, the first gas supplied from the gas storage unit (40) may flow along the first gas path (4a) and then be injected into the processing space (200) through the first gas path (4a). The first gas path (4a) may function as a path for the first gas to flow and may also function as an injection port for injecting the first gas into the processing space (200).

[0026] The second gas path (4b) is for injecting the second gas. The second gas and the first gas may be different gases. For example, when the first gas is a source gas, the second gas may be a reactant gas. One end of the second gas path (4b) may be connected to the gas storage unit (40) through a pipe, a hose, a gas block, or the like. The other end of the second gas path (4b) may be connected to the processing space (200). Accordingly, the second gas supplied from the gas storage unit (40) may flow along the second gas path (4b) and then be injected into the processing space (200) through the second gas path (4b). The above second gas path (4b) can function as a path for the second gas to flow and can also function as an injection port for injecting the second gas into the processing space (200).

[0027] The second gas path (4b) and the first gas path (4a) may be arranged to be spatially separated from each other. Accordingly, the second gas supplied from the gas storage unit (40) to the second gas path (4b) may be injected into the processing space (200) without passing through the first gas path (4a). The first gas supplied from the gas storage unit (40) to the first gas path (4a) may be injected into the processing space (200) without passing through the second gas path (4b). The second gas path (4b) and the first gas path (4a) may inject gas toward different parts of the processing space (200).

[0028] For example, as shown in FIG. 2, the injection unit (4) may include a first plate (41) and a second plate (42).

[0029] The first plate (41) is disposed on the upper side of the second plate (42). The first plate (41) and the second plate (42) may be disposed spaced apart from each other. A plurality of first gas holes (411) may be formed in the first plate (41). Each of the first gas holes (411) may function as a passage for the first gas to flow. The first gas holes (411) may belong to the first gas path (4a). A plurality of second gas holes (412) may be formed in the first plate (41). Each of the second gas holes (412) may function as a passage for the second gas to flow. The second gas holes (412) may belong to the second gas path (4b). A plurality of protruding members (413) may be combined with the first plate (41). The protruding members (413) may protrude from the lower surface of the first plate (41) toward the second plate (42). Each of the first gas holes (411) may be formed by penetrating the first plate (41) and the protruding members (413).

[0030] A plurality of openings (421) may be formed in the second plate (42). The openings (421) may be formed by penetrating the second plate (42). The openings (421) may be arranged at positions corresponding to the respective protruding members (413). As illustrated in FIG. 2, the protruding members (413) may be formed to have a length such that they are inserted into each of the openings (421). Although not illustrated, the protruding members (413) may also be formed to have a length such that they are arranged above each of the openings (421). The protruding members (413) may also be formed to have a length such that they protrude downward from the second plate (42). The second gas holes (412) may be arranged to inject gas toward the upper surface of the second plate (42). Although not shown, the lower surface of the first plate (41) may be formed flat without the protruding member (413).

[0031] For example, as illustrated in FIG. 3, a plurality of first openings (422) and a plurality of second openings (423) may be formed in the second plate (42).

[0032] The first openings (422) may be formed by penetrating the second plate (42). The second openings (423) may be formed by penetrating the second plate (42). The second plate (42) and the first plate (41) may be arranged to be spaced apart from each other. The lower surface of the first plate (41) facing the second plate (42) may be formed flat without the protruding member (413, illustrated in FIG. 2). The first gas and the second gas may be supplied to the space between the first plate (41) and the second plate (42) through the first gas holes (411) and the second gas holes (412), and then sprayed into the processing space (200) through the first openings (422) and the second openings (423). In this case, when the supply of the first gas through the first gas holes (411) and the supply of the second gas through the second gas holes (412) are performed simultaneously, the first gas and the second gas can be mixed in the space between the first plate (41) and the second plate (42) and then sprayed into the processing space (200) through the first openings (422) and the second openings (423).

[0033] Meanwhile, the first openings (422) may be arranged vertically below each of the first gas holes (411). In this case, the first openings (422) and the first gas holes (411) may be arranged on the same vertical line. Although not shown, the first openings (422) and the first gas holes (411) may be arranged at staggered positions. In this case, the first openings (422) and the first gas holes (411) may be arranged at positions where they do not overlap each other, or may be arranged at positions where they only partially overlap each other.

[0034] Meanwhile, the second openings (423) may be arranged vertically below each of the second gas holes (412). In this case, the second openings (423) and the second gas holes (412) may be arranged on the same vertical line. Although not shown, the second openings (423) and the second gas holes (412) may be arranged at staggered positions. In this case, the second openings (423) and the second gas holes (412) may be arranged at positions where they do not overlap each other, or may be arranged at positions where they only partially overlap each other.

[0035] Meanwhile, the injection unit (4) can form plasma using the second plate (42) and the first plate (41). In this case, plasma power, such as RF power, may be applied to the first plate (41), and the second plate (42) may be grounded. The first plate (41) may be grounded, and plasma power may be applied to the second plate (42).

[0036] The thin film formation method according to the present invention can be performed through a substrate processing device (1) of this type.

[0037] Referring to FIGS. 1 to 5, the thin film forming method according to the present invention is for forming the thin film on the substrate (100). As illustrated in FIG. 4, the thin film forming method according to the present invention can form a gallium nitride (GaN) film (110) on the substrate (100). To this end, the thin film forming method according to the present invention may include the following steps.

[0038] First, a substrate (100) is prepared (S10). This step (S10) can be performed by preparing a substrate (100) on which at least one film (120) (hereinafter referred to as a “lower film (120)”) is formed. The step (S10) of preparing the substrate can be performed by placing the substrate (100) on which the lower film (120) is formed on the substrate support member (3). In this case, the step (S10) of preparing the substrate can be performed by a transport robot (not shown) that transports the substrate (100). The step (S10) of preparing the substrate can also be performed by forming the lower film (120) on the substrate (100) supported on the substrate support member (3). The lower film (120) can include one or more films selected from a metal film, a metal oxide film, a silicon nitride (SiN) film, and a silicon oxide (SiO) film. In this case, the lower film (120) may be a single film including any one of a metal film, a metal oxide film, a silicon nitride (SiN) film, and a silicon oxide (SiO) film, or may be a composite film in which two or more of a metal film, a metal oxide film, a silicon nitride (SiN) film, and a silicon oxide (SiO) film are laminated.In addition, the substrate (100) or the lower film (120) may be silicon (Si), silicon nitride (SiN), silicon oxide (SiO), germanium (Ge), gallium nitride (GaN), gallium arsenide (GaAs), graphene, sapphire, indium phosphide (InP), indium nitride (InN), indium gallium nitride (InGaN), indium gallium phosphide (InGaP), aluminum gallium phosphide (AlGaP), aluminum indium gallium nitride (AlInGaN), aluminum gallium arsenide (AlGaAsP), indium aluminum gallium arsenide (InAlGaAsP), indium gallium arsenide phosphide (InGaAsP), aluminum nitride (AlN), glass substrate, silver, gold, cesium, copper, aluminum, titanium, nickel, iron, molybdenum, platinum, It may be a substrate (100) or a lower film (120) including one or more of tungsten, zirconium, hafnium, strontium, lanthanum, yttrium, ruthenium, and lead. Meanwhile, the lower film (120) may be formed to cover the entire upper surface of the plate (100). The lower film (120) may also be formed to cover a portion of the upper surface of the substrate (100).

[0039] Next, a gallium-containing source gas is injected (S20). This step (S20) can be performed by having the injection unit (4) inject the gallium-containing source gas onto the substrate (100). The gallium-containing source gas can be injected into the processing space (200) through the first gas path (4a), thereby being injected toward the substrate (100) supported by the substrate support unit (3). Through the step (S20) of injecting the gallium-containing source gas, an adsorption process in which gallium is adsorbed can be performed. For example, trimethyl gallium (Ga(CH3)3) (TMGa) can be used as the gallium-containing source gas.

[0040] Next, a gallium nitride film (110) is formed (S30). This step (S30) can be performed by having the injection unit (4) inject a nitrogen (N)-containing reactant gas onto the substrate (100). The nitrogen-containing reactant gas can be injected into the processing space (200) through the second gas path (4b), thereby being injected toward the substrate (100) supported by the substrate support unit (3). As the nitrogen-containing reactant gas is injected onto the substrate (100), a deposition process can be performed in which the gallium adsorbed by the adsorption process reacts with the nitrogen-containing reactant gas to deposit the gallium nitride film (110). In this case, the gallium nitride film (110) can be formed by an atomic layer deposition (ALD) method.

[0041] The step (S30) of forming the gallium nitride film may be performed by forming the gallium nitride film (110) on the substrate (100) at a temperature of 300 degrees (°C) to 600 degrees (°C). In this case, the step (S30) of forming the gallium nitride film may be performed when the temperature of the processing space (200) or the temperature of the substrate (100) is 300 degrees or more and 600 degrees or less. Accordingly, the method for forming a thin film according to the present invention can reduce the risk of the lower film (120) being damaged by high temperature during the process of forming the gallium nitride film (110), and can improve the quality of the substrate (100) on which the processing process is performed by improving the film quality of the lower film (120). The method for forming a thin film according to the present invention may also be implemented so that the step (S20) of injecting the gallium-containing source gas is performed at a temperature of 300 degrees to 600 degrees. Therefore, the thin film forming method according to the present invention can further reduce the risk of damage to the lower film (120) due to high temperature, and can further improve the quality of the substrate (100) on which the processing is performed through improvement in the film quality of the lower film (120).

[0042] Meanwhile, when the lower film (120) is formed at the first process temperature, the step (S30) of forming the gallium nitride film can be performed at a temperature lower than the first process temperature. Accordingly, the method for forming a thin film according to the present invention is implemented so that the step (S30) of forming the gallium nitride film is performed at a temperature not higher than the temperature at which the lower film (120) is formed. Therefore, the method for forming a thin film according to the present invention can reduce the risk of the lower film (120) being damaged by high temperature during the process of forming the gallium nitride film (110), and can improve the quality of the substrate (100) on which the processing is performed through the improvement of the film quality of the lower film (120). When the first process temperature is a temperature range, the step (S30) of forming the gallium nitride film can be performed at a temperature equal to the maximum value of the first process temperature or at a temperature lower than the maximum value of the first process temperature. For example, when the first process temperature is 300 degrees or more and 600 degrees or less, the step (S30) of forming the gallium nitride film may be performed at a temperature of 600 degrees or less. The step (S30) of forming the gallium nitride film may also be performed at the same temperature as the first process temperature. The thin film forming method according to the present invention may also be implemented so that the step (S20) of injecting the gallium-containing source gas may be performed at a temperature lower than the first process temperature. Therefore, the thin film forming method according to the present invention can further reduce the risk of the lower film (120) being damaged by high temperature, and can further improve the quality of the substrate (100) on which the processing is performed by improving the film quality of the lower film (120).

[0043] The step (S30) of forming the gallium nitride film may include a step (S31) of injecting a nitrogen-containing reactant gas. The step (S31) of injecting the nitrogen-containing reactant gas may be performed by the injection unit (4) injecting the nitrogen-containing reactant gas into the processing space (200) through the second gas path (4b). Ammonia (NH3) may be used as the nitrogen-containing reactant gas.

[0044] The step (30) of forming the gallium nitride film may include a step (S32) of forming a first plasma. The step (S32) of forming the first plasma may be performed by forming plasma in the processing space (200). The step (S32) of forming the first plasma may form plasma using a gas containing argon (Ar), helium (He), hydrogen (H2-), and germanium (Ge) when injecting the nitrogen-containing reactant gas. Accordingly, the thin film forming method according to the present invention can remove impurities in the step (S30) of forming the gallium nitride film through the step (S32) of forming the first plasma. Therefore, the thin film forming method according to the present invention can improve the quality of the substrate (100) on which the processing process is performed by improving the film quality of the gallium nitride film (110).

[0045] In addition, the plasma formed through the step of forming the first plasma (S32) can provide additional energy for forming the gallium nitride film (110). Accordingly, the thin film forming method according to the present invention can increase the deposition rate of the gallium nitride film (110) by using the energy provided by the plasma even if the step of forming the gallium nitride film (S30) is performed at a relatively low temperature of 300 to 600 degrees. Therefore, the thin film forming method according to the present invention can increase the productivity of the substrate (100) on which the gallium nitride film (110) is formed while preventing damage to the lower film (120) due to temperature. The step of forming the first plasma (S32) can form plasma by using the first plate (41) and the second plate (42). In this case, plasma can be formed by applying plasma power to one of the first plate (41) and the second plate (42) and grounding the other.

[0046] The step (S32) of forming the first plasma may be performed by forming plasma using the nitrogen-containing reactant gas. Accordingly, the method for forming a thin film according to the present invention is implemented so that the nitrogen-containing reactant gas can be used for both the reaction with gallium adsorbed on the substrate and the formation of the plasma. The step (S32) of forming the first plasma may also be performed by forming plasma using ammonia (NH3) injected as the nitrogen-containing reactant gas. In this case, ammonia is not decomposed at a temperature of 300 to 600 degrees at which the step (S30) of forming the gallium nitride film is performed, but the method for forming a thin film according to the present invention can decompose ammonia even at a temperature of 300 to 600 degrees through the plasma formed using ammonia to react with the gallium adsorbed on the substrate.

[0047] The thin film forming method according to the present invention may include a step (S40) of forming a second plasma. The step (S40) of forming the second plasma may be performed by forming plasma in the processing space (200) using argon (Ar), helium (H2), hydrogen (H2), and germanium (Ge) injected through the injection unit (4). Hydrogen may be injected into the processing space (200) through at least one of the first gas path (4a) and the second gas path (4b).

[0048] The step of forming the second plasma (S40) may be performed after the step of injecting the nitrogen-containing reactant gas (S31) is performed. Accordingly, the method for forming a thin film according to the present invention can remove impurities from the gallium nitride film (110) formed on the substrate (100), and thus reduce the content of impurities included in the gallium nitride film (110). Accordingly, the method for forming a thin film according to the present invention can form the gallium nitride film (110) having further improved film quality. In this case, impurities included in the gallium nitride film (110) can react with plasma and escape from the gallium nitride film (110). The step of forming the second plasma (S40) may be performed after the step of forming the gallium nitride film (S30) is performed. If the step of forming the gallium nitride film (S30) includes the step of forming the first plasma (S32), the step of forming the second plasma (S40) may be performed after the step of forming the first plasma (S32) is performed.

[0049] The step of forming the second plasma (S40) may be performed between the step of injecting the gallium-containing source gas (S20) and the step of injecting the nitrogen-containing reactant gas (S31). The step of forming the second plasma (S40) may form plasma using a gas containing argon (Ar), helium (He), hydrogen (H2-), and germanium (Ge). In this case, the thin film forming method according to the present invention can remove impurities from the gallium adsorbed on the substrate (100), and thus form the gallium nitride film (110) having further improved film quality. The step of forming the second plasma (S40) may be performed between the step of injecting the gallium-containing source gas (S20) and the step of injecting the nitrogen-containing reactant gas (S31), and may be additionally performed after the step of injecting the nitrogen-containing reactant gas (S31) is performed.

[0050] The thin film forming method according to the present invention may further include the following steps.

[0051] First, a first purge gas is injected (S50). This step (S50) can be performed by the injection unit (4) injecting the first purge gas into the processing space (200). The first purge gas can be injected toward the substrate (100) supported on the substrate support unit (3) through at least one of the first gas path (4a) and the second gas path (4b). The first purge gas can be an inert gas such as argon (Ar). The step (S50) of injecting the first purge gas can be performed after the step of injecting the gallium-containing source gas is performed. Accordingly, a purge process can be performed to purge the gallium-containing source gas, etc., which was not used in the adsorption process, from the processing space (200) through the step (S50) of injecting the first purge gas. After the step (S50) of injecting the first purge gas is performed, the step (S30) of forming the gallium nitride film can be performed.

[0052] Next, a second purge gas is injected (S60). This step (S60) can be performed by the injection unit (4) injecting the second purge gas into the processing space (200). The second purge gas can be injected toward the substrate (100) supported on the substrate support unit (3) through at least one of the first gas path (4a) and the second gas path (4b). The second purge gas can be an inert gas such as argon. The step of injecting the second purge gas (S60) can be performed after the step of forming the gallium nitride film (S30) is performed. Accordingly, a purge process can be performed to purge the nitrogen-containing reactant gas, etc., which is not used in the deposition process, from the processing space (200) through the step of injecting the second purge gas (S60). After the step of injecting the second purge gas (S60) is performed, the step of forming the second plasma (S40) can be performed.

[0053] Here, when a metal film is formed as the lower film (120) on the substrate (100) prepared through the step of preparing the substrate (S10), the metal film may be formed using one or more types of metals mixed among tungsten (W), iridium (Ir), osmium (Os), rhodium (Rh), platinum (Pt), silver (Ag), rhenium (Re), palladium (Pd), copper (Cu), aluminum (Al), aluminum nitride (AlN), zirconium (Zr), hafnium (Hf), silicon (Si), lanthanum (La), and oxide films or nitride films thereof.

[0054] For example, when the gallium nitride film (110) is provided in a three-dimensional transistor as illustrated in FIG. 6, the gallium nitride film (110) may be formed on a word line (WL) corresponding to the lower film (120). The word line (WL) may be connected to or included in a gate line of the three-dimensional transistor. The word line (WL) may play a role in determining whether to use a memory cell in the three-dimensional transistor. The word line (WL) may be formed using one or a metal mixed with two or more types of tungsten (W), iridium (Ir), osmium (Os), rhodium (Rh), platinum (Pt), silver (Ag), rhenium (Re), palladium (Pd), copper (Cu), aluminum (Al), and aluminum nitride (AlN). The thin film forming method according to the present invention forms the gallium nitride film (110) on the word line (WL) at a temperature of 300 to 600 degrees, so that the gallium nitride film (110) can be formed on the word line (WL) while preventing damage to the word line (WL) due to temperature. The gallium nitride film (110) can be implemented as an active layer in a three-dimensional transistor.

[0055] When the gallium nitride film (110) is provided in a three-dimensional transistor, the gallium nitride film (110) may be formed on an insulating film (I). The insulating film (I) may be included in the lower film (120) and may be formed on the word line (WL). The insulating film (I) may be formed of a high-k material. For example, the insulating film (I) may be formed using one or a metal mixed with two or more types of a zirconium oxide film (ZrO), a hafnium oxide film (HfO), a silicon oxide film (SiO), and a lanthanum oxide film (LaO). The thin film forming method according to the present invention forms the gallium nitride film (110) on an insulating film (I) formed of a high-k material at a temperature of 300 to 600 degrees, so that the gallium nitride film (110) can be formed on the insulating film (I) while preventing damage to the insulating film (I) due to temperature.

[0056] When the gallium nitride film (110) is provided in a three-dimensional transistor, the gallium nitride film (110) may be formed on a bit line (BL). The bit line (BL) may be connected to a source electrode or a drain electrode of the three-dimensional transistor or may be included in the source electrode or the drain electrode. The bit line (BL) may serve to confirm the value (0 or 1) of the memory stored in the three-dimensional transistor. The bit line (BL) may be formed using one or a metal mixed with two or more types of tungsten (W), iridium (Ir), osmium (Os), rhodium (Rh), platinum (Pt), silver (Ag), rhenium (Re), palladium (Pd), copper (Cu), aluminum (Al), and aluminum nitride (AlN). The thin film forming method according to the present invention forms the gallium nitride film (110) on the bit line (BL) at a temperature of 300 to 600 degrees, so that the gallium nitride film (110) can be formed on the bit line (BL) while preventing damage to the bit line (BL) due to temperature.

[0057] For example, when the gallium nitride film (110) is provided in a bottom gate type transistor as illustrated in FIG. 7, the gallium nitride film (110) may be formed on a gate insulating film (GI). In this case, the gate insulating film (GI) may correspond to the lower film (120). A gate electrode (GE) may be formed on the substrate (100), and the gate insulating film (GI) may be formed to cover the substrate (100) and the gate electrode (GE). The gallium nitride film (110) may be formed to cover a portion of the gate insulating film (GI). The gate insulating film (GI) may be formed of a high-k material. For example, the gate insulating film (GI) may be formed using one or a metal mixed with two or more types of a zirconium oxide film (ZrO), a hafnium oxide film (HfO), a silicon oxide film (SiO), and a lanthanum oxide film (LaO). The thin film forming method according to the present invention forms the gallium nitride film (110) on a gate insulating film (GI) formed of a high-k material at a temperature of 300 to 600 degrees, so that the gallium nitride film (110) can be formed on the gate insulating film (GI) while preventing damage to the gate insulating film (GI) due to temperature. Meanwhile, a source electrode (SE) and a drain electrode (DE) can be formed on the gallium nitride film (110) and the gate insulating film (GI). The gallium nitride film (110) can be implemented as an active layer in a bottom gate type transistor.

[0058] For example, when the gallium nitride film (110) is provided in a top gate type transistor as illustrated in FIG. 8, the gallium nitride film (110) may be formed on a source electrode (SE) and a drain electrode (DE). In this case, the source electrode (SE) and the drain electrode (DE) may correspond to the lower film (120). The gallium nitride film (110) may be formed to cover a portion of the source electrode (SE), a portion of the drain electrode (DE), and a portion of the substrate (100). The source electrode (SE) and the drain electrode (DE) may be formed using one or a metal mixed with two or more of tungsten (W), iridium (Ir), osmium (Os), rhodium (Rh), platinum (Pt), silver (Ag), rhenium (Re), palladium (Pd), copper (Cu), aluminum (Al), and aluminum nitride (AlN). The thin film forming method according to the present invention forms the gallium nitride film (110) on the source electrode (SE) and the drain electrode (DE) at a temperature of 300 to 600 degrees, so that the gallium nitride film (110) can be formed on the source electrode (SE) and the drain electrode (DE) while preventing damage to the source electrode (SE) and the drain electrode (DE) due to temperature. Meanwhile, a gate insulating film (GI) can be formed on the gallium nitride film (110). A gate electrode (GE) can be formed on the gate insulating film (GI). The gallium nitride film (110) can be implemented as an active layer in a top gate type transistor.

[0059] Hereinafter, an embodiment of a substrate processing device according to the present invention will be described in detail with reference to the attached drawings.

[0060] Referring to FIGS. 1 to 9, the substrate processing device (300) according to the present invention is for forming the gallium nitride film (110) on the substrate (100). The substrate processing device (300) according to the present invention can form the gallium nitride film (110) on the substrate (100) by performing the nitride-containing film forming method according to the present invention described above. The substrate processing device (300) according to the present invention can form the gallium nitride film (110) by atomic layer deposition.

[0061] A substrate processing device (300) according to the present invention may include a chamber (310), a substrate support unit (320) installed inside the chamber (310) to support the substrate (100), a first gas injection unit (330a) and a second gas injection unit (330b) installed inside the chamber (310) to face the substrate support unit (320), a gas supply unit (340) for providing a process gas to the first gas injection unit (330a) and the second gas injection unit (330b), an antenna (351) having a coil for inducing an electric field inside the chamber (310) for plasma generation, and a power supply unit (352) connected to the antenna (351).

[0062] In addition, the substrate processing device (300) according to the present invention may include a heating unit (360) installed to face the substrate support unit (320), a driving unit (370) that raises and lowers or rotates the substrate support unit (320), and an exhaust unit (380) that exhausts gas and impurities inside the chamber (310).

[0063] The chamber (310) has a cylindrical shape having an internal space in which a thin film can be formed on the substrate (100) brought in, and may be, for example, a dome shape as illustrated in FIG. 9. More specifically, the chamber (310) may include a chamber body (311), an upper body (312) installed on the upper side of the chamber body (311), and a lower body (313) installed on the lower side of the chamber body (311). The chamber body (311) may be a cylindrical shape with an upper and a lower side open, and the upper body (312) may be installed to cover the upper opening of the chamber body (311), and the lower body (313) may be installed to cover the lower opening of the chamber body (311). In addition, the upper body (312) 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 (313) may have a dome shape having a slope whose height decreases toward the center in the width direction. Each of the chamber body (311), the upper body (312), and the lower body (313) may be made of a transparent material that allows light to pass through, and may be made of, for example, quartz.

[0064] The above gas supply unit (340) may include a source gas supply unit (341) for supplying the gallium-containing source gas, a reactant gas supply unit (342) for supplying the nitrogen-containing reactant gas, a purge gas supply unit (343) for supplying purge gas, a hydrogen gas supply unit (344) for supplying hydrogen gas, and a discharge gas supply unit (345) for supplying a gas for discharge.

[0065] In addition, the gas supply unit (340) may include a first transport pipe (346a) installed to connect the source gas supply unit (341) and the reactant gas supply unit (342) to the first gas injection unit (330a). The gas supply unit (340) may include a second transport pipe (346b) installed to connect the purge gas supply unit (343), the hydrogen gas supply unit (344), and the discharge gas supply unit (345) to the second gas injection unit (330b).

[0066] In addition, the gas supply unit (340) may include a plurality of first connecting pipes (347a) that connect the source gas supply unit (341) and the reactant gas supply unit (342) to the first transport pipe (346a). The gas supply unit (340) may include a valve installed in each of the first connecting pipes (347a). The gas supply unit (340) may include a plurality of second connecting pipes (347b) that connect the purge gas supply unit (343), the hydrogen gas supply unit (344), and the discharge gas supply unit (345) to the second transport pipe (346b). The gas supply unit (340) may include a valve installed in each of the second connecting pipes (347b).

[0067] The substrate processing device (300) according to the present invention can form the gallium nitride film (110) on the substrate (100) by performing the following processing process.

[0068] First, the transport robot places the substrate (100) on which the lower film (120) is formed, on the substrate support member (320). The lower film (120) may include at least one of a metal film, a metal oxide film, a silicon nitride (SiN) film, and a silicon oxide (SiO) film. When a metal film is formed as the lower film (120), the metal film may be formed using one or a mixture of two or more types of metals selected from the group consisting of tungsten (W), iridium (Ir), osmium (Os), rhodium (Rh), platinum (Pt), silver (Ag), rhenium (Re), palladium (Pd), copper (Cu), aluminum (Al), aluminum nitride (AlN), zirconium (Zr), hafnium (Hf), silicon (Si), lanthanum (La), and oxide films or nitride films thereof. In addition, the substrate (100) or the lower film (120) may be silicon (Si), silicon nitride (SiN), silicon oxide (SiO), germanium (Ge), gallium nitride (GaN), gallium arsenide (GaAs), graphene, sapphire, indium phosphide (InP), indium nitride (InN), indium gallium nitride (InGaN), indium gallium phosphide (InGaP), aluminum gallium phosphide (AlGaP), aluminum indium gallium nitride (AlInGaN), aluminum gallium arsenide (AlGaAsP), indium aluminum gallium arsenide (InAlGaAsP), indium gallium arsenide phosphide (InGaAsP), aluminum nitride (AlN), glass substrate, silver, gold, cesium, copper, aluminum, titanium, nickel, iron, molybdenum, platinum, It may be a substrate (100) or a lower film (120) containing one or more of tungsten, zirconium, hafnium, strontium, lanthanum, yttrium, ruthenium, and lead.

[0069] Next, the source gas supply unit (341) and the first gas injection unit (330a) inject the gallium-containing source gas into the interior of the chamber (310). Accordingly, an adsorption process in which gallium is adsorbed onto the substrate (100) can be performed.

[0070] Next, the reactant gas supply unit (342) and the first gas injection unit (330a) inject the nitrogen-containing reactant gas into the interior of the chamber (310). Accordingly, a deposition process can be performed in which the gallium adsorbed by the adsorption process reacts with the nitrogen-containing reactant gas to deposit the gallium nitride film (110). In this case, the gallium nitride film (110) can be formed by an atomic layer deposition method.

[0071] Meanwhile, the heating unit (360) can control the temperature of the processing space (200) or the temperature of the substrate (100) to 300 degrees or more and 600 degrees or less. Accordingly, the substrate processing device (300) according to the present invention can reduce the risk of the lower film (120) being damaged by high temperature during the process of forming the gallium nitride film (110) on the substrate (100), and can improve the quality of the substrate (100) on which the processing process is performed by improving the film quality of the lower film (120).

[0072] By repeating this cycle once or more times, the substrate processing device (300) according to the present invention can form the gallium nitride film (110) on the substrate (100).

[0073] The substrate processing device (300) according to the present invention can perform a purge process of purging the interior of the chamber (310) by injecting a purge gas into the interior of the chamber (310) using the purge gas supply unit (343) and the second gas injection unit (330b). This purge process can include a first purge process performed after injecting the gallium-containing source gas, and a second purge process performed after injecting the nitrogen-containing reactant gas. After the first purge process is performed, the nitrogen-containing reactant gas can be injected. After the second purge process is performed, the nitrogen-containing reactant gas can be injected.

[0074] The substrate processing device (300) according to the present invention can form plasma inside the chamber (310) when injecting the nitrogen-containing reactant gas. In this case, the substrate processing device (300) according to the present invention can inject discharge gas into the chamber (310) together with the discharge gas supply unit (345) and the second gas injector unit (330b) when injecting the nitrogen-containing reactant gas. The discharge gas may be argon (Ar). In addition, the substrate processing device (300) according to the present invention can form plasma inside the chamber (310) by applying power to the antenna (351). Accordingly, the nitrogen-containing reactant gas can be discharged to form nitrogen plasma. Accordingly, the substrate processing device (300) according to the present invention can increase the deposition rate of the gallium nitride film (110) by using the energy provided by the plasma even when performing the process of forming the gallium nitride film (110) at a relatively low temperature of 300 to 600 degrees. Accordingly, the substrate processing device (300) according to the present invention can increase the productivity of the substrate (100) on which the gallium nitride film (110) is formed while preventing damage to the lower film (120) due to temperature.

[0075] The substrate processing device (300) according to the present invention can form hydrogen plasma inside the chamber (310) by using the hydrogen gas supply unit (344), the discharge gas supply unit (345), the second gas injection unit (330b), and the antenna (351). The hydrogen gas supply unit (344), the discharge gas supply unit (345), and the second gas injection unit (330b) inject hydrogen gas and discharge gas into the interior of the chamber (310), and by applying power to the antenna (351), hydrogen plasma can be formed inside the chamber (310).

[0076] In this case, the substrate processing device (300) according to the present invention can form hydrogen plasma after forming the gallium nitride film (110) by injecting the nitrogen-containing reactant gas. Accordingly, the substrate processing device (300) according to the present invention can remove impurities from the gallium nitride film (110) using hydrogen plasma, and thus can reduce the content of impurities included in the gallium nitride film (110). Accordingly, the substrate processing device (300) according to the present invention can form the gallium nitride film (110) with further improved film quality. The substrate processing device (300) according to the present invention can also form hydrogen plasma between the injection of the gallium-containing source gas and the injection of the nitrogen-containing reactant gas. Accordingly, the substrate processing device (300) according to the present invention can remove impurities from gallium adsorbed on the substrate (100) using hydrogen plasma, thereby forming the gallium nitride film (110) having a more improved film quality.

[0077] The present invention described above is not limited to the above-described embodiments and the attached drawings, and it will be apparent to a person skilled in the art to which the present invention pertains that various substitutions, modifications, and changes are possible within a scope that does not depart from the technical spirit of the present invention.

Claims

1. A method for forming a thin film on a substrate, A step for preparing a substrate on which one or more lower films of a metal film, a metal oxide film, a silicon nitride (SiN) film, and a silicon oxide (SiO) film are formed; A step of spraying a gallium (Ga) containing source gas onto the substrate; and A method for forming a thin film, comprising the step of spraying a nitrogen (N)-containing reactant gas onto the substrate and forming a gallium nitride (GaN) film on the substrate at a temperature of 300 to 600 degrees.

2. In paragraph 1, The step of forming the above gallium nitride film is performed by injecting the nitrogen-containing reactant gas, argon (Ar), helium (He), hydrogen (H). 2 -), a thin film forming method including a step of forming a first plasma using a gas containing germanium (Ge).

3. In paragraph 1, A method for forming a thin film, characterized in that the metal film is formed using one or more metals selected from the group consisting of ruthenium (Ru), tungsten (W), iridium (Ir), osmium (Os), rhodium (Rh), platinum (Pt), silver (Ag), rhenium (Re), palladium (Pd), copper (Cu), aluminum (Al), aluminum nitride (AlN), zirconium (Zr), hafnium (Hf), silicon (Si), and lanthanum (La), and oxide films or nitride films thereof.

4. In paragraph 1, A step of forming a second plasma is performed between the step of injecting the gallium-containing source gas and the step of injecting the nitrogen-containing reactant gas. The step of forming the second plasma is argon (Ar), helium (He), and hydrogen (H). 2 -), a method for forming a thin film by forming a plasma using a gas containing germanium (Ge).

5. In paragraph 1, After the step of injecting the above nitrogen-containing reactant gas is performed, Argon (Ar), helium (He), hydrogen (H 2 -), a method for forming a thin film including a step of forming a second plasma using a gas containing germanium (Ge).

6. In paragraph 1, The step of forming the above gallium nitride film is: A method for forming a thin film, comprising a step of injecting ammonia (NH3) as a nitrogen-containing reactant gas and forming a first plasma using ammonia.

7. In paragraph 1, The step of forming the above gallium nitride film is: A method for forming a thin film by forming the gallium nitride film on a source electrode and a drain electrode when the gallium nitride film is provided in a top gate type transistor.

8. In paragraph 1, The step of forming the above gallium nitride film is: A method for forming a thin film by forming the gallium nitride film on a gate insulating film when the gallium nitride film is provided in a bottom gate type transistor.

9. In paragraph 1, The substrate or the lower film is silicon (Si), silicon nitride (SiN), silicon oxide (SiO), germanium (Ge), gallium nitride (GaN), gallium arsenide (GaAs), graphene, sapphire, indium phosphide (InP), indium nitride (InN), indium gallium nitride (InGaN), indium gallium phosphide (InGaP), aluminum gallium phosphide (AlGaP), aluminum indium gallium nitride (AlInGaN), aluminum gallium arsenide phosphide (AlGaAsP), indium aluminum gallium arsenide phosphide (InAlGaAsP), indium gallium arsenide phosphide (InGaAsP), aluminum nitride (AlN), glass, silver, gold, cesium, copper, aluminum, titanium, nickel, iron, molybdenum, platinum, tungsten, zirconium, hafnium, A method for forming a thin film, which is a substrate or a lower film containing one or more of strontium, lanthanum, yttrium, ruthenium and lead.

10. A method for forming a thin film on a substrate, A step for preparing a substrate on which one or more lower films of a metal film, a metal oxide film, a silicon nitride (SiN) film, and a silicon oxide (SiO) film are formed at a first process temperature; A step of spraying a gallium (Ga) containing source gas onto the substrate; and Comprising a step of spraying a nitrogen (N)-containing reactant gas onto the above substrate, A method for forming a thin film, wherein the first process temperature is 300 to 600 degrees.

11. In paragraph 10, The step of forming the above gallium nitride film is performed by injecting the nitrogen-containing reactant gas, argon (Ar), helium (He), hydrogen (H). 2 -), a method for forming a thin film including a step of forming a first plasma using a gas containing germanium (Ge).

12. In paragraph 10, The above metal film is a thin film forming method using one or more metals selected from the group consisting of ruthenium (Ru), tungsten (W), iridium (Ir), osmium (Os), rhodium (Rh), platinum (Pt), silver (Ag), rhenium (Re), palladium (Pd), copper (Cu), aluminum (Al), aluminum nitride (Al), zirconium (Zr), hafnium (Hf), silicon (Si), lanthanum (La), and oxide films or nitride films thereof.

13. In paragraph 10, Comprising a step of forming a plasma performed between the step of injecting the gallium-containing source gas and the step of injecting the nitrogen-containing reactant gas, The step of forming the above plasma is argon (Ar), helium (He), hydrogen (H 2 -), a method for forming a thin film including a step of forming a second plasma using a gas containing germanium (Ge).

14. In paragraph 10, After the step of injecting the above nitrogen-containing reactant gas is performed, Argon (Ar), helium (He), hydrogen (H 2 -), a method for forming a thin film including a step of forming a second plasma using a gas containing germanium (Ge).

15. In paragraph 10, The substrate or the lower film is silicon (Si), silicon nitride (SiN), silicon oxide (SiO), germanium (Ge), gallium nitride (GaN), gallium arsenide (GaAs), graphene, sapphire, indium phosphide (InP), indium nitride (InN), indium gallium nitride (InGaN), indium gallium phosphide (InGaP), aluminum gallium phosphide (AlGaP), aluminum indium gallium nitride (AlInGaN), aluminum gallium arsenide phosphide (AlGaAsP), indium aluminum gallium arsenide phosphide (InAlGaAsP), indium gallium arsenide phosphide (InGaAsP), aluminum nitride (AlN), glass, silver, gold, cesium, copper, aluminum, titanium, nickel, iron, molybdenum, platinum, tungsten, zirconium, hafnium, A method for forming a thin film, which is a substrate or a lower film containing one or more of strontium, lanthanum, yttrium, ruthenium and lead.

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