Method of forming film

Abstract

The present disclosure relates to a method of forming a film on a substrate, and relates to a film forming method including a step of preparing the substrate on which a lower film of one or more of a metal film, a metal oxide film, a silicon nitride (SiN) film, and a silicon oxide (SiO) film is formed, a step of spraying a gallium (Ga)-containing source gas onto the substrate, and a step of forming a gallium (Ga)-containing source gas on the substrate. And a step of spraying a nitrogen (N)-containing reactant gas onto the substrate at a temperature of 300 DEG C to 600 DEG C and forming a gallium nitride (GaN) film on the substrate.

Description

TECHNICAL FIELD

[0001] The present disclosure relates to a film forming method for forming a gallium-containing film. BACKGROUND

[0002] Generally, a film layer, a film circuit pattern, or an optical pattern should be formed on a substrate for manufacturing a solar cell, a semiconductor device, a flat panel display device, or the like. To this end, a process is performed on the substrate, and examples of the process include a deposition process of depositing a film including a specific material on the substrate, an exposure process of selectively exposing a portion of the film by using a photosensitive material, an etching process of removing the film of the selectively exposed portion to form a pattern, and the like. Such a process can be performed on the substrate by a substrate processing apparatus.

[0003] The substrate processing apparatus can perform a process of forming a gallium (Ga)-containing film on the substrate. The gallium-containing film has a wide band gap and a high electron mobility, and thus is attracting attention as a material for implementing high speed, low loss, and high efficiency. Such a gallium-containing film can be applied to a transistor of a three-dimensional (3D) structure and a power semiconductor device.

[0004] Here, in the related prior art, the gallium-containing film has been formed on a lower film formed on the substrate in a high-temperature environment of 700°C or higher. Therefore, in the related prior art, there is a problem that the risk of damage to the lower film in the process of forming the gallium-containing film is high, and a problem that the film quality of the lower film is deteriorated. SUMMARY

[0005] PROBLEMS TO BE SOLVED BY THE INVENTION The present disclosure is directed to solving the above problems, and is directed to providing a film forming method that can reduce the risk of damage to a lower film in a process of forming a gallium-containing film.

[0006] MEANS FOR SOLVING THE PROBLEMS To achieve the above object, the present disclosure can include the following elements.

[0007] The film forming method according to the present disclosure is a method of forming a film on a substrate, and can include a step of preparing the substrate on which one or two or more layers of a lower film 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 step of spraying a nitrogen (N)-containing reaction gas onto the substrate at a temperature of 300°C to 600°C and forming a gallium nitride (GaN) film on the substrate.

[0008] The film formation method disclosed herein is a method for forming a film on a substrate, and may include: the steps of preparing the substrate having one or more lower films selected from metal films, metal oxide films, silicon nitride (SiN) films, and silicon oxide (SiO) films at a first process temperature; the steps of injecting gallium (Ga) source gas onto the substrate; and the steps of injecting nitrogen (N) reactive gas onto the substrate. The first process temperature may be from 300°C to 600°C.

[0009] Beneficial effects According to this disclosure, the following effects can be achieved.

[0010] This disclosure is implemented to reduce the risk of the film formed on the substrate being damaged by high temperatures during the process of forming a gallium-containing film. Therefore, this disclosure can improve the quality of the film formed on the substrate, and thus can improve the quality of the substrate that has undergone the processing. Attached Figure Description

[0011] Figure 1 This is a schematic diagram illustrating an example of a substrate processing apparatus for performing a film formation method according to the present disclosure.

[0012] Figure 2 as well as Figure 3 This is a side cross-sectional schematic diagram of a gas injection unit in an example of a substrate processing apparatus for performing a film formation method according to the present disclosure.

[0013] Figure 4 This is a side cross-sectional schematic diagram illustrating an example of a substrate formed by a film forming method according to the present disclosure, containing a gallium film.

[0014] Figure 5 This is a schematic flowchart of the membrane formation method according to the present disclosure.

[0015] Figures 6 to 8 This is a side cross-sectional schematic diagram illustrating another example of a substrate formed with a gallium-containing film according to the film formation method of this disclosure.

[0016] Figure 9 This is a schematic diagram illustrating the structure of a substrate processing apparatus according to the present disclosure. Detailed Implementation

[0017] Hereinafter, an embodiment of the membrane formation method according to the present disclosure will be described in detail with reference to the accompanying drawings. In describing embodiments of the present disclosure, when any structure is described as being formed on another structure, this description should be interpreted to include cases where a third structure is disposed between these structures, and cases where these structures are in contact with each other.

[0018] Please refer to Figures 1 to 5The film formation method according to this disclosure is used to form a gallium-containing film on a substrate 100. The substrate 100 can be a silicon substrate, a glass substrate, a metal substrate, etc. The film can be incorporated into semiconductor devices, display devices, solar cells, etc. For example, the film can be incorporated into power semiconductor devices, transistors having a three-dimensional (3D) structure, etc.

[0019] The film formation method according to this disclosure can be performed using substrate processing apparatus 1. Before describing an embodiment of the film formation method according to this disclosure, an example of substrate processing apparatus 1 will be described in detail below.

[0020] Please refer to Figures 1 to 5 The substrate processing equipment 1 may include a cavity 2, a substrate support unit 3, and a spraying unit 4.

[0021] The cavity 2 provides a processing space 200. Film formation processes can be performed within the processing space 200. The processing space 200 can be disposed within the cavity 2. An exhaust port (not shown) for discharging gas from the processing space 200 can be integrated into the cavity 2. A substrate support unit 3 and an injection unit 4 can be disposed within the cavity 2.

[0022] The substrate support unit 3 supports the substrate 100. The substrate support unit 3 can support one substrate 100 or multiple substrates 100. When the substrate support unit 3 supports these substrates 100, processing techniques can be performed on these substrates 100 simultaneously. The substrate support unit 3 can be integrated into the cavity 2. The substrate support unit 3 can be disposed within the cavity 2.

[0023] The injection unit 4 injects gas toward the substrate support unit 3. The injection unit 4 can be connected to the gas storage unit 40. In this case, the injection unit 4 can inject gas supplied from the gas storage unit 40 toward the substrate support unit 3. The injection unit 4 can be disposed within the cavity 2. The injection unit 4 can be positioned relative to the substrate support unit 3. The injection unit 4 can be disposed on the substrate support unit 3. The processing space 200 can be disposed between the injection unit 4 and the substrate support unit 3. The injection unit 4 can be attached to a cover (not shown). The cover can be attached to the cavity 2 to cover the top of the cavity 2.

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

[0025] The first gas flow path 4a is used to inject a first gas. One side of the first gas flow path 4a can be connected to the gas storage unit 40 via a pipe, hose, gas block, etc. The other side of the first gas flow path 4a can be connected to the processing space 200. Therefore, the first gas supplied from the gas storage unit 40 can flow along the first gas flow path 4a and then be injected into the processing space 200 through the first gas flow path 4a. The first gas flow path 4a can function as a flow path for enabling the first gas to flow and can also function as an injection port for injecting the first gas into the processing space 200.

[0026] The second gas flow path 4b is used to inject a second gas. The second gas and the first gas can be different gases. For example, when the first gas is the source gas, the second gas can be the reactant gas. One side of the second gas flow path 4b can be connected to the gas storage unit 40 via a flow pipe, hose, gas holder, etc. The other side of the second gas flow path 4b can be connected to the processing space 200. Therefore, the second gas supplied from the gas storage unit 40 can flow along the second gas flow path 4b and then be injected into the processing space 200 through the second gas flow path 4b. The second gas flow path 4b can function as a flow path for enabling 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 flow path 4b and the first gas flow path 4a can be spatially separated from each other. Therefore, the second gas supplied from the gas storage unit 40 to the second gas flow path 4b can be injected into the processing space 200 without passing through the first gas flow path 4a. The first gas supplied from the gas storage unit 40 to the second gas flow path 4b can be injected into the processing space 200 without passing through the second gas flow path 4b. The second gas flow path 4b and the first gas flow path 4a can inject gas towards different parts of the processing space 200.

[0028] For example, such as Figure 2 As shown, the injection unit 4 may include a first plate 41 and a second plate 42.

[0029] A first plate 41 is disposed on a second plate 42. The first plate 41 and the second plate 42 may be spaced apart from each other. A plurality of first gas holes 411 may be formed in the first plate 41. Each of these first gas holes 411 may function as a path for allowing a first gas to flow. The first gas holes 411 may be included in a first gas flow path 4a. A plurality of second gas holes 412 may be formed in the second plate 42. Each of these second gas holes 412 may function as a path for allowing a second gas to flow. The second gas holes 412 may be included in a second gas flow path 4b. A plurality of protrusions 413 may be attached to the first plate 41. The protrusions 413 may protrude from the lower surface of the first plate 41 toward the second plate 42. Each of these first gas holes 411 may be formed to pass through the first plate 41 and the protrusions 413.

[0030] Multiple openings 421 can be formed in the second plate 42. The openings 421 can be formed to pass through the second plate 42. These openings 421 can be provided at multiple locations corresponding to the protrusions 413. For example... Figure 2 As shown, these protrusions 413 can be formed by a length that allows them to be inserted into the openings 421 respectively. Although not shown, these protrusions 413 can be formed by a length that allows them to be disposed on the openings 421 respectively. These protrusions 413 can be formed by a length that protrudes downward from the second plate 42. The second gas hole 412 can be configured to inject gas toward the upper surface of the second plate 42. Although not shown, the lower surface of the first plate 41 can be formed flat without protrusions 413.

[0031] For example, such as Figure 3 As shown, a plurality of first openings 422 and a plurality of second openings 423 may be formed in the second plate 42.

[0032] The first opening 422 can be formed to pass through the second plate 42. The second opening 423 can be formed to pass through the second plate 42. The second plate 42 and the first plate 41 can be arranged to be spaced apart from each other. The lower surface of the first plate 41 facing the second plate 42 can be formed to be flat without a protrusion 413 (e.g., Figure 2(As shown). The first gas and the second gas can be supplied to the space between the first plate 41 and the second plate 42 through the first gas hole 411 and the second gas hole 412, and then injected into the processing space 200 through the first opening 422 and the second opening 423. In this case, when the first gas is supplied through the first gas hole 411 and the second gas is supplied through the second gas hole 412 simultaneously, the first gas and the second gas can mix in the space between the first plate 41 and the second plate 42, and then be injected into the processing space 200 through the first opening 422 and the second opening 423.

[0033] Furthermore, multiple first openings 422 can be vertically disposed below multiple first gas holes 411. In this case, the first openings 422 and the first gas holes 411 can be disposed on the same vertical line. Although not shown, the first openings 422 and the first gas holes 411 can be disposed in staggered positions. In this case, the first openings 422 and the first gas holes 411 can be disposed in non-overlapping positions, or only a portion thereof can be disposed in overlapping positions.

[0034] Furthermore, multiple second openings 423 can be vertically disposed below multiple second gas holes 412. In this case, the second openings 423 and the second gas holes 412 can be disposed on the same vertical line. Although not shown, the second openings 423 and the second gas holes 412 can be disposed in staggered positions. In this case, the second openings 423 and the second gas holes 412 can be disposed in non-overlapping positions, or only a portion thereof can be disposed in overlapping positions.

[0035] Furthermore, the injection unit 4 can generate plasma using a second plate 42 and a first plate 41. In this case, a plasma power source, such as radio frequency (RF) power, can be applied to the first plate 41, and the second plate 42 can be grounded. The first plate 41 can be grounded, and the plasma power source can be applied to the second plate 42.

[0036] The film formation method according to this disclosure can be performed using substrate processing equipment 1.

[0037] Please refer to Figures 1 to 5 The film formation method according to this disclosure is used to form a film on a substrate 100. For example... Figure 4 As shown, a gallium nitride (GaN) film 110 can be formed on a substrate 100 according to the film formation method of this disclosure. For this purpose, the film formation method according to this disclosure may include the following steps.

[0038] First, substrate 100 is prepared (S10). This step S10 can be performed by preparing a substrate 100 having at least one film 120 (hereinafter referred to as "lower film 120"). The substrate preparation step S10 can be performed by supporting (using substrate support unit 3) the substrate 100 on which the lower film 120 is formed. In this case, the substrate preparation step S10 can be performed by a transport machine (not shown) that transports the substrate 100. The substrate preparation step S10 can be performed by forming the lower film 120 on the substrate 100 supported by the substrate support unit 3. The lower film 120 may comprise one or more of 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 can be a single film comprising one of a metal film, a metal oxide film, a silicon nitride (SiN) film, and a silicon oxide (SiO) film, or it can be a composite film having two or more of the following stacked: a metal film, a metal oxide film, a silicon nitride (SiN) film, and a silicon oxide (SiO) film. Furthermore, the substrate 100 or the lower film 120 may comprise one or more of the following: 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 (InGaAsP), aluminum nitride (AlN), glass, silver, gold, cesium, copper, aluminum, titanium, nickel, iron, molybdenum, platinum, tungsten, zirconium, hafnium, strontium, lanthanum, yttrium, ruthenium, and lead. Additionally, the lower film 120 may be formed to cover the entire upper surface of the substrate 100. The lower film 120 can be formed as part of the upper surface of the substrate 100.

[0039] Subsequently, a gallium-containing source gas is sprayed (S20). This step S20 can be performed by spraying the gallium-containing source gas onto the substrate 100 using the spraying unit 4. The gallium-containing source gas can be sprayed into the processing space 200 through the first gas flow path 4a, and thus can be sprayed toward the substrate 100 supported by the substrate support unit 3. The gallium adsorption process can be performed by spraying the gallium-containing source gas in step S20. For example, trimethylgallium (Ga(CH3)3) (TMGa) can be used as the gallium-containing source gas.

[0040] Subsequently, a gallium nitride film 110 is formed (S30). This step S30 can be performed by spraying a nitrogen-containing reactive gas onto the substrate 100 using the spraying unit 4. The nitrogen-containing reactive gas can be sprayed into the processing space 200 through the second gas flow path 4b, and thus can be sprayed toward the substrate 100 supported by the substrate support unit 3. When the nitrogen-containing reactive gas is sprayed onto the substrate 100, a deposition process can be performed to react the nitrogen-containing reactive gas with gallium adsorbed by the adsorption process to deposit the gallium nitride film 110. In this case, the gallium nitride film 110 can be formed by an atomic layer deposition (ALD) process.

[0041] Step S30, forming a gallium nitride film, can be performed by forming a gallium nitride film 110 on the substrate 100 at a temperature of 300°C to 600°C. In this case, step S30 can be performed at a temperature of 300°C to 600°C in the processing space 200 or at a temperature of 300°C to 600°C. Therefore, the film formation method according to this disclosure reduces the risk of the lower film 120 being damaged by high temperatures during the process of forming the gallium nitride film 110, and improves the quality of the lower film 120, thereby improving the quality of the processed substrate 100. The film formation method according to this disclosure can be implemented by performing step S20, which involves spraying a gallium-containing source gas, at a temperature of 300°C to 600°C. Therefore, the film formation method according to this disclosure further reduces the risk of the lower film 120 being damaged by high temperatures, and improves the quality of the lower film 120, thereby further improving the quality of the processed substrate 100.

[0042] Furthermore, when the lower film 120 is formed at the first process temperature, step S30 of forming the gallium nitride film can be performed at a temperature lower than or equal to the first process temperature. Therefore, the film formation method according to this disclosure is implemented such that step S30 of forming the gallium nitride film is performed at a temperature not higher than that of forming the lower film 120. Therefore, the film formation method according to this disclosure can reduce the risk of the lower film 120 being damaged by high temperatures during the process of forming the gallium nitride film 110, and can improve the film quality of the lower film 120, thereby improving the quality of the processed substrate 100. When the first process temperature is a temperature range value, step S30 of forming the gallium nitride film can be performed at a temperature equal to or lower than the maximum value of the first process temperature. For example, when the first process temperature is between 300°C and 600°C, step S30 of forming the gallium nitride film can be performed at a temperature below 600°C. Step S30 of forming the gallium nitride film can also be performed at the same temperature as the first process temperature. The film formation method according to this disclosure can be implemented such that step S20, which involves spraying gallium-containing source gas, is performed at a temperature lower than or equal to the first process temperature. Therefore, the film formation method according to this disclosure can further reduce the risk of the lower film 120 being damaged by high temperatures and can improve the quality of the lower film 120, thereby further improving the quality of the processed substrate 100.

[0043] Step S30, which forms the gallium nitride film, may include step S31, which involves injecting a nitrogen-containing reactive gas. Step S31 involves injecting the nitrogen-containing reactive gas into the processing space 200 via a second gas flow path 4b. Ammonia (NH3) may be used as the nitrogen-containing reactive gas.

[0044] Step S30 of forming a gallium nitride film may include step S32 of forming a first plasma. Step S32 of forming the first plasma can be performed by forming a plasma in the processing space 200. In the case of injecting a nitrogen-containing reactive gas, step S32 of forming the first plasma can be performed by using a gas containing argon (Ar), helium (He), hydrogen (H2), and germanium (Ge). Therefore, according to the film formation method of this disclosure, impurities can be removed in step S30 of forming the gallium nitride film by step S32 of forming the first plasma. Therefore, according to the film formation method of this disclosure, the film quality of the gallium nitride film 110 can be improved, thereby improving the quality of the processed substrate 100.

[0045] Furthermore, the plasma formed in step S32, which forms the first plasma, can provide additional energy for forming the gallium nitride film 110. Therefore, even when step S30, which forms the gallium nitride film, is performed at a relatively low temperature of 300°C to 600°C, the film formation method according to this disclosure can still reduce the deposition rate of the gallium nitride film 110 by using the energy provided by the plasma. Thus, the film formation method according to this disclosure can prevent damage to the lower film 120 caused by temperature and can increase the yield of the substrate 100 on which the gallium nitride film 110 is formed. Step S32, which forms the first plasma, can be performed using a first plate 41 and a second plate 42. In this case, plasma can be formed when a plasma power supply is applied to one of the first plate 41 and the second plate 42 and the other is grounded.

[0046] Step S32, which involves forming a first plasma, can be performed by using a nitrogen-containing reactive gas to form a plasma. Therefore, in the film formation method of this disclosure, a nitrogen-containing reactive gas is used to react with gallium adsorbed onto the substrate to form a plasma. Step S32, which involves forming a first plasma, can be performed by using sprayed ammonia (NH3) as the nitrogen-containing reactive gas to form a plasma. In this case, ammonia will not decompose at the temperature of 300°C to 600°C used in step S30, which involves forming a gallium nitride film. Furthermore, according to the film formation method of this disclosure, ammonia can be decomposed by using a plasma formed with ammonia at a temperature of 300°C to 600°C, thereby enabling ammonia to react with gallium adsorbed onto the substrate.

[0047] The membrane formation method according to this disclosure may include a step S40 of forming a second plasma. Step S40 of forming the second plasma can be performed by forming a plasma in a processing space 200 using a gas containing argon (Ar), helium (He), hydrogen (H2), and germanium (Ge). Hydrogen can be injected into the processing space 200 through at least one of a first gas flow path 4a and a second gas flow path 4b.

[0048] The step of forming a second plasma, S40, can be performed after the step of injecting nitrogen-containing reactive gas, S31. Therefore, according to the film formation method of this disclosure, impurities can be removed from the gallium nitride film 110 formed on the substrate 100, and thus the impurity content contained in the gallium nitride film 110 can be reduced. According to the film formation method of this disclosure, a gallium nitride film 110 with further improved film quality can be formed. In this case, impurities contained in the gallium nitride film 110 can react with the plasma to leave the gallium nitride film 110. The step of forming a second plasma, S40, can be performed after the step of forming the gallium nitride film, S30. When the step of forming the gallium nitride film, S30, includes the step of forming a first plasma, the step of forming a second plasma, S40, can be performed after the step of forming the first plasma, S32.

[0049] The step S40 of forming a second plasma can be performed between the step S20 of injecting gallium-containing source gas and the step S31 of injecting nitrogen-containing reactive gas. The step S40 of forming the second plasma can be performed using a gas containing argon (Ar), helium (He), hydrogen (H2), and germanium (Ge). In this case, impurities can be removed from gallium adsorbed on the substrate 100 according to the film formation method of this disclosure, and thus a gallium nitride film 110 with further improved film quality can be formed. The step S40 of forming the second plasma can be performed between the step S20 of injecting gallium-containing source gas and the step S31 of injecting nitrogen-containing reactive gas, and can also be performed additionally after the step S31 of injecting nitrogen-containing reactive gas.

[0050] The membrane formation method according to this disclosure may also include the following steps.

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

[0052] Subsequently, a second purging gas is injected (S60). This step S60 can be performed by injecting the second purging gas into the processing space 200 using the injection unit 4. The second purging gas can be injected toward the substrate 100 supported by the substrate support unit 3 through at least one of the first gas flow path 4a and the second gas flow path 4b. The second purging gas can be an inert gas such as argon (Ar). The step S60 of injecting the second purging gas can be performed after the step S30 of injecting the gallium-containing source gas. Therefore, the step S60 of injecting the second purging gas can be used to perform a purging process to remove gases such as nitrogen-containing reactive gases that are not used in the deposition process from the processing space 200. The step S40 of forming a second plasma can be performed after the step S60 of injecting the second purging gas.

[0053] Here, when the metal film is formed as a lower film on the substrate 100 prepared by step S10 of preparing the substrate, the metal film may be a metal film formed by using a metal formed by combining one or more of the following materials: 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 of the aforementioned metals.

[0054] For example, such as Figure 6 As shown, when the gallium nitride film 110 is included in a three-dimensional (3D) transistor, the gallium nitride film 110 can be formed on the word line WL corresponding to the lower film 120. The word line WL can be connected to the gate line of the 3D transistor, or it can be included in the gate line. The word line WL can determine whether a memory cell is used for a function in the 3D transistor. The word line WL can be formed using a metal formed by combining one or more materials selected from tungsten (W), iridium (Ir), osmium (Os), rhodium (Rh), platinum (Pt), silver (Ag), rhenium (Re), palladium (Pd), copper (Cu), aluminum (Al), and aluminum nitride (AlN). According to the film formation method of this disclosure, the gallium nitride film 110 can be formed on the word line WL at a temperature of 300°C to 600°C, and therefore the gallium nitride film 110 can be formed on the word line WL while preventing damage to the word line WL caused by temperature. The gallium nitride film 110 can be implemented as an active layer in a 3D transistor.

[0055] When the gallium nitride film 110 is included in a 3D transistor, the gallium nitride film 110 can be formed on the insulating film I. The insulating film I can be included in the lower film 120 and can be formed on the word line WL. The insulating film I can be formed of a high-dielectric (high-K) material. For example, the insulating film I can be formed using a metal formed by combining one or more of zirconium oxide (ZrO), hafnium oxide (HfO), silicon oxide (SiO), and lanthanum oxide (LaO). According to the film formation method of this disclosure, the gallium nitride film 110 can be formed on the insulating film I formed of a high-K material at a temperature of 300°C to 600°C, and thus the gallium nitride film 110 can be formed on the insulating film I while preventing damage to the insulating film I caused by temperature.

[0056] When the gallium nitride film 110 is incorporated into a 3D transistor, the gallium nitride film 110 can be formed on the bit line BL. The bit line BL can be connected to or contained within the source or drain of the 3D transistor. The bit line BL can function to confirm the value (0 or 1) of the memory stored in the 3D transistor. The bit line BL can be formed by combining one or more materials selected from tungsten (W), iridium (Ir), osmium (Os), rhodium (Rh), platinum (Pt), silver (Ag), rhenium (Re), palladium (Pd), copper (Cu), aluminum (Al), and aluminum nitride (AlN). According to the film formation method of this disclosure, the gallium nitride film 110 can be formed on the bit line BL at a temperature of 300°C to 600°C, and thus the gallium nitride film 110 can be formed on the bit line BL while preventing damage to the bit line BL caused by temperature.

[0057] For example, such as Figure 7As shown, when the gallium nitride film 110 is included in the bottom gate transistor, the gallium nitride film 110 can be formed on the gate insulating film GI. In this case, the gate insulating film GI can correspond to the lower film 120. The gate GE can be formed on the substrate 100, and the gate insulating film GI can be formed to cover the substrate 100 to the gate GE. The gallium nitride film 110 can be formed to cover a portion of the gate insulating film GI. The gate insulating film GI can be formed from a high-K material. For example, the gate insulating film GI can be formed using a metal, which is formed by combining one or more materials selected from zirconium oxide (ZrO), hafnium oxide (HfO), silicon oxide (SiO), and lanthanum oxide (LaO). According to the film formation method of this disclosure, the gallium nitride film 110 can be formed on the gate insulating film GI formed from a high-K material at a temperature of 300°C to 600°C, and therefore, the gallium nitride film 110 can be formed on the gate insulating film GI while preventing damage to the gate insulating film GI caused by temperature. Furthermore, the source (SE) and drain (DE) can be formed on the gallium nitride film 110 to be on the gate insulating film (GI). The gallium nitride film 110 can be implemented as the active layer in a bottom-gate transistor.

[0058] For example, such as Figure 8 As shown, when the gallium nitride film 110 is included in the top gate transistor, the gallium nitride film 110 can be formed on the source SE and drain DE. In this case, the source SE and drain DE can correspond to the lower film 120. The gallium nitride film 110 can be formed to cover a portion of the source SE, a portion of the drain DE, and a portion of the substrate 100. The source SE and drain DE can be formed using a metal, which is formed by combining one or more materials selected from tungsten (W), iridium (Ir), osmium (Os), rhodium (Rh), platinum (Pt), silver (Ag), rhenium (Re), palladium (Pd), copper (Cu), aluminum (Al), and aluminum nitride (AlN). According to the film formation method of this disclosure, a gallium nitride film 110 can be formed on the source SE and drain DE at a temperature of 300°C to 600°C, and therefore, the gallium nitride film 110 can be formed on the source SE and drain DE while preventing damage to the source SE and drain DE caused by temperature. The gate 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 transistor.

[0059] Hereinafter, embodiments of the substrate processing apparatus according to the present disclosure will be described in detail with reference to the accompanying drawings.

[0060] Please refer to Figures 1 to 9The substrate processing apparatus 300 according to this disclosure is used to form a gallium nitride film 110 on a substrate 100. The substrate processing apparatus 300 according to this disclosure can perform the nitride film formation method according to the present disclosure described above, and therefore, a gallium nitride film 110 can be formed on the substrate 100. The substrate processing apparatus 300 according to this disclosure can form the gallium nitride film 110 using an atomic layer deposition process.

[0061] The substrate processing apparatus 300 according to this disclosure may include a cavity 310, a substrate support unit 320 mounted in the cavity 310 for supporting a substrate 100, a first gas injection unit 330a and a second gas injection unit 330b mounted in the cavity 310 to face the substrate support unit 320, a gas supply unit 340 for supplying process gas to the first gas injection unit 330a and the second gas injection unit 330b, an antenna 351 including a coil for inducing an electric field in the cavity 310 to generate plasma, and a power supply unit 352 connected to the antenna 351.

[0062] Furthermore, the substrate processing apparatus 300 according to this disclosure may include a heating unit 360 mounted relative to the substrate support unit 320, a driver 370 for raising, lowering or rotating the substrate support unit 320, and a discharge unit 380 for discharging impurities and internal gases from the discharge chamber 310.

[0063] The cavity 310 may have a cylindrical shape in which a membrane can be formed on a substrate 100 loaded inside it, and for example, such as Figure 9 As shown, it can have a dome shape. Specifically, the cavity 310 can include a cavity body 311, an upper body 312 mounted on the cavity body 311, and a lower body 313 mounted below the cavity body 311. The cavity body 311 can have a cylindrical shape with an open top and bottom. The upper body 312 can be mounted to cover the upper opening of the cavity body 311, and the lower body 313 can be mounted to cover the lower opening of the cavity body 311. Furthermore, the upper body 312 can have a dome shape including a sloping surface whose height gradually increases towards its width center. Similarly, the lower body 313 can have a dome shape including a sloping surface whose height gradually decreases towards its width center. Each of the cavity body 311, upper body 312, and lower body 313 can be provided with a transparent material through which light can pass, and for example, quartz can be provided.

[0064] The gas supply unit 340 may include a source gas supply unit 341 for supplying gallium-containing source gas, a reaction gas supply unit 342 for supplying nitrogen-containing reaction gas, a purging gas supply unit 343 for supplying purging gas, a hydrogen supply unit 344 for supplying hydrogen, and a release gas supply unit 345 for supplying release gas.

[0065] Furthermore, the gas supply unit 340 may include a first transfer conduit 346a configured to connect the source gas supply unit 341 and the reaction gas supply unit 342 to the first gas injection unit 330a. The gas supply unit 340 may also include a second transfer conduit 346b configured to connect the purge gas supply unit 343, the hydrogen supply unit 344, and the release gas supply unit 345 to the second gas injection unit 330b.

[0066] Furthermore, the gas supply unit 344 may include a plurality of first connecting pipes 347a connecting the source gas supply unit 341 and the reaction gas supply unit 342 to the first transfer pipe 346a. The gas supply unit 340 may include a valve body installed in each of these first connecting pipes 347a. The gas supply unit 340 may include a plurality of second transfer pipes 347b connecting the purge gas supply unit 343, the hydrogen supply unit 344, and the release gas supply unit 345 to the second transfer pipe 346b. The gas supply unit 340 may include a valve body installed in each of these second transfer pipes 347b.

[0067] According to the present disclosure, the substrate processing apparatus 300 can perform the following processing steps to form a gallium nitride film 110 on the substrate 100.

[0068] First, the conveying machine supports the substrate 100 on which the lower film 120 is formed using a substrate support unit 320. The lower film 120 may comprise at least one of a metal film, a metal oxide film, a silicon nitride (SiN) film, and a silicon oxide (SiO) film. When the lower film 120 is formed of a metal film, the metal film may be a metal film formed by using one or more of the following materials: 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 or nitride films of the aforementioned metals. Furthermore, the substrate 100 or the lower film 120 may contain one or more of the following: 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 (InGaAsP), aluminum nitride (AlN), glass, silver, gold, cesium, copper, aluminum, titanium, nickel, iron, molybdenum, platinum, tungsten, zirconium, hafnium, strontium, lanthanum, yttrium, ruthenium, and lead.

[0069] Subsequently, the source gas supply unit 341 and the first gas injection unit 330a inject gallium-containing source gas into the cavity 310. Therefore, an adsorption process for adsorbing gallium onto the substrate 100 can be performed.

[0070] Subsequently, the reactive gas supply unit 342 and the first gas injection unit 330a inject nitrogen-containing reactive gas into the cavity 310. Therefore, a deposition process can be performed to react the nitrogen-containing reactive gas with gallium adsorbed by an adsorption process to deposit a gallium nitride film 110. In this case, the gallium nitride film 110 can be formed by an atomic layer deposition process.

[0071] Furthermore, the heating unit 360 can adjust the temperature of the processing space 200 or the substrate 100 to 300°C to 600°C. Therefore, the substrate processing apparatus 300 according to this disclosure can reduce the risk of high-temperature damage to the lower film 120 during the process of forming the gallium nitride film 110, and can improve the film quality of the lower film 120, thereby improving the quality of the substrate 100 that has undergone the processing.

[0072] By repeating this cycle more than once, the substrate processing apparatus 300 according to the present disclosure can form a gallium nitride film 110 on the substrate 100.

[0073] The substrate processing apparatus 300 according to this disclosure can perform a purging process by injecting purging gas into a cavity 310 to purge the interior of the cavity 310 using a purging gas supply unit 343 and a second gas injection unit 330b. This purging process can include a first purging process performed after injecting a gallium-containing source gas, and a second purging process performed after injecting a nitrogen-containing reactive gas. After the first purging process, a nitrogen-containing reactive gas can be injected. After the second purging process, a nitrogen-containing reactive gas can be injected.

[0074] The substrate processing apparatus 300 according to this disclosure can form plasma in the cavity 310 when a nitrogen-containing reactive gas is injected. In this case, when the nitrogen-containing reactive gas is injected, the substrate processing apparatus 300 according to this disclosure can inject the release gas into the cavity 310 together using a release gas supply unit 345 and a second gas injection unit 330b. The release gas can be argon (Ar). Furthermore, the substrate processing apparatus 300 according to this disclosure can apply power to the antenna 351, and therefore, plasma can be formed in the cavity 310. Therefore, nitrogen-containing reactive gas can be released, and nitrogen plasma can be formed. Therefore, even when the process for forming the gallium nitride film 110 is performed at a relatively low temperature of 300°C to 600°C, the substrate processing apparatus 300 according to this disclosure can still increase the deposition rate of the gallium nitride film 110 by using the energy provided by the plasma. Therefore, the substrate processing apparatus 300 according to the present disclosure can prevent damage to the lower film 120 caused by temperature and can increase the yield of the substrate 100 on which the gallium nitride film 110 is formed.

[0075] The substrate processing apparatus 300 according to this disclosure can form hydrogen plasma in a cavity 310 by using a hydrogen supply unit 344, a release gas supply unit 345, a second gas injection unit 330b, and an antenna 351. The hydrogen supply unit 344, the release gas supply unit 345, and the second gas injection unit 330b can inject hydrogen and release gas into the cavity 310, and power can be applied to the antenna 351, thus hydrogen plasma can be formed in the cavity 310.

[0076] In this case, the substrate processing apparatus 300 according to the present disclosure can spray a nitrogen-containing reactive gas to form a gallium nitride film 110, and then a hydrogen plasma can be formed. Therefore, the substrate processing apparatus 300 according to the present disclosure can remove impurities from the gallium nitride film 110 by using hydrogen plasma, and thus can reduce the impurity content contained in the gallium nitride film 110. Therefore, the substrate processing apparatus 300 according to the present disclosure can improve the gallium nitride film 110 with a further improved film quality. The substrate processing apparatus 300 according to the present disclosure can form a hydrogen plasma between the spraying of the gallium-containing source gas and the spraying of the nitrogen-containing reactive gas. Therefore, the substrate processing apparatus 300 according to the present disclosure can remove impurities from gallium adsorbed on the substrate 100 by using hydrogen plasma, and thus can form a gallium nitride film 110 with a further improved film quality.

[0077] The present disclosure is not limited to the above embodiments and the accompanying drawings, and those skilled in the art will clearly understand that various modifications, variations and substitutions can be made without departing from the spirit and scope of the present disclosure.

Claims

1. A method for forming a film on a substrate, the method comprising: The step of preparing the substrate having one or more lower films formed from metal films, metal oxide films, silicon nitride (SiN) films and silicon oxide (SiO) films; The step of injecting gallium (Ga) source gas onto the substrate; as well as The step of spraying a nitrogen-containing (N) reactive gas onto the substrate at a temperature of 300°C to 600°C and forming a gallium nitride (GaN) film on the substrate.

2. The method as described in claim 1, wherein, The step of forming the gallium nitride film includes: forming a first plasma by using a gas containing argon (Ar), helium (He), hydrogen (H2) and germanium (Ge) while the nitrogen-containing reactive gas is being injected.

3. The method as described in claim 1, wherein, The metal film is formed by using one or more of the following metals: 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), as well as oxide or nitride films of the aforementioned metals.

4. The method of claim 1, comprising: The step of forming a second plasma occurs between the step of injecting the gallium-containing source gas and the step of injecting the nitrogen-containing reactive gas, and The step of forming the second plasma is to form the plasma by using a gas containing argon (Ar), helium (He), hydrogen (H2) and germanium (Ge).

5. The method of claim 1, comprising: Following the step of injecting the nitrogen-containing reactive gas, a second plasma is formed by using a gas containing argon (Ar), helium (He), hydrogen (H2), and germanium (Ge).

6. The method of claim 1, wherein, The step of forming the gallium nitride film includes the steps of spraying ammonia (NH3) as the nitrogen-containing reactive gas and forming a first plasma by using ammonia.

7. The method of claim 1, wherein, When the gallium nitride film is included in a top gate transistor, the step of forming the gallium nitride film involves forming the gallium nitride film on the source and drain electrodes.

8. The method of claim 1, wherein, When the gallium nitride film is included in the bottom gate transistor, the step of forming the gallium nitride film involves forming the gallium nitride film on the gate insulating film.

9. The method of claim 1, wherein, The substrate or the lower film comprises one or more of the following: 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 (InGaAsP), aluminum nitride (AlN), glass, silver, gold, cesium, copper, aluminum, titanium, nickel, iron, molybdenum, platinum, tungsten, zirconium, hafnium, strontium, lanthanum, yttrium, ruthenium, and lead.

10. A method for forming a film on a substrate, the method comprising: The step of preparing the substrate having one or more lower films selected from metal films, metal oxide films, silicon nitride (SiN) films and silicon oxide (SiO) films at a first process temperature; The step of injecting gallium (Ga) source gas onto the substrate; and The step of spraying nitrogen-containing (N) reactive gas onto the substrate. The first process temperature is between 300°C and 600°C.

11. The method of claim 10, wherein, The steps of forming a gallium nitride film include: forming a first plasma by using a gas containing argon (Ar), helium (He), hydrogen (H2) and germanium (Ge) while the nitrogen-containing reactive gas is being injected.

12. The method of claim 10, wherein, The metal film is formed by using one or more of the following metals: 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), as well as oxide or nitride films of the aforementioned metals.

13. The method of claim 10, comprising: The plasma formation step occurs between the step of injecting the gallium-containing source gas and the step of injecting the nitrogen-containing reactive gas, and The steps for forming the plasma include forming a second plasma by using a gas containing argon (Ar), helium (He), hydrogen (H2) and germanium (Ge).

14. The method of claim 10, further comprising, after the step of injecting the nitrogen-containing reactive gas, a step of forming a second plasma by using a gas containing argon (Ar), helium (He), hydrogen (H2), and germanium (Ge).

15. The method of claim 10, wherein, The substrate or the lower film comprises one or more of the following: 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 (InGaAsP), aluminum nitride (AlN), glass, silver, gold, cesium, copper, aluminum, titanium, nickel, iron, molybdenum, platinum, tungsten, zirconium, hafnium, strontium, lanthanum, yttrium, ruthenium, and lead.

Images