Method for removing impurities in a thin film and substrate processing equipment

Abstract

The present invention relates to a method for removing impurities in a thin film and a substrate processing apparatus. The method for removing impurities in a thin film includes the following steps: providing a substrate having a thin film formed thereon in a process chamber; supplying a first gas that reacts with and binds to the impurities contained in the thin film into the process chamber; after stopping the supply of the first gas, discharging the combined product of the impurities and the first gas by decompressing the interior of the process chamber; curing the thin film by supplying a second gas different from the first gas into the process chamber; and stopping the supply of the second gas and discharging the remaining second gas from the interior of the process chamber. The present invention effectively removes the impurities contained in the thin film.

Description

Technical Field

[0001] The present invention relates to a method for removing impurities from a thin film and a substrate processing apparatus, and more particularly, to a method for removing impurities from a thin film and a substrate processing apparatus for removing impurities from a thin film. Background Art

[0002] During a semiconductor manufacturing process, methods such as atomic layer deposition (ALD) and chemical vapor deposition (CVD) are used to deposit a thin film, and the thin film is used as a semiconductor device. Here, a metal precursor compound containing a metal element and a ligand (or a bonding element) is mainly used as a source gas for thin film deposition.

[0003] Generally, when a metal precursor compound is used to deposit a thin film, the bond between the metal element and the ligand is not effectively broken, and thus a metal element (or an oxide or nitride of the metal element) having a part of the ligand is deposited. Therefore, the ligand may be an impurity in the thin film, which causes a problem of increasing the resistivity (or dielectric constant) of the thin film.

[0004] Recently, with the requirements for high performance and high integration of semiconductor devices and the miniaturization of device size, a technique for improving the resistivity (or dielectric constant) characteristics of a thin film used as a semiconductor device is required, and thus a method for effectively removing impurities from the thin film is required.

[0005] [Prior Art Document]

[0006] Korean Patent Publication No. 10-1999-0059064 Summary of the Invention

[0007] [Problems to be Solved]

[0008] The present invention provides a method for removing impurities from a thin film and a substrate processing apparatus to effectively remove impurities contained in the thin film by sequentially performing a plurality of gas supplies and reduced pressure exhausts.

[0009] [Means for Solving the Problems]

[0010] According to an embodiment, a method for removing impurities in a thin film includes the following steps: providing a substrate having a thin film formed thereon in a process chamber; supplying a first gas that reacts with and binds to the impurities contained in the thin film into the process chamber; after stopping the supply of the first gas, discharging a coupled product of the impurities and the first gas by decompressing the interior of the process chamber; curing the thin film by supplying a second gas different from the first gas into the process chamber; and stopping the supply of the second gas and discharging the remaining second gas from the interior of the process chamber.

[0011] The step of supplying the first gas may be carried out at a first pressure of 0.1 Torr to 20 Torr within the process chamber, and the step of discharging the coupled product may be carried out at a second pressure of 0.1 mTorr to 20 mTorr lower than the first pressure by decompressing the interior of the process chamber.

[0012] The impurities may include carbon (C), and the first gas may include hydrogen (H).

[0013] The thin film may include a metal element, and the second gas may include oxygen (O).

[0014] The step of supplying the first gas may be carried out for a first time period, and the step of discharging the coupled product may be carried out for a second time period shorter than the first time period.

[0015] The step of supplying the first gas may be carried out at a temperature of 100°C to 400°C.

[0016] The step of curing the thin film may include reacting an element in the second gas with the surface of the thin film to form a cured layer.

[0017] The cured layer may have or less than a thickness of.

[0018] The step of supplying the first gas, the step of discharging the coupled product, the step of curing the thin film, and the step of discharging the remaining second gas may be repeated multiple times.

[0019] According to another embodiment, a substrate processing apparatus includes: a process chamber in which a substrate having a thin film formed thereon is loaded and unloaded; a first gas supply unit configured to supply a first gas into the process chamber, the first gas reacting with and bonding to impurities contained in the thin film; a second gas supply unit configured to supply a second gas into the process chamber, the second gas being different from the first gas; a heater unit disposed outside the process chamber to provide thermal energy to the interior of the process chamber; an exhaust unit configured to exhaust the interior of the process chamber; and a control unit configured to control the first gas supply unit, the second gas supply unit, and the exhaust unit, the first gas supply unit being capable of supplying the first gas under the control of the control unit to generate a bonding product through the reaction of the impurities with the first gas, the exhaust unit being capable of exhausting the bonding product under the control of the control unit, and the second gas supply unit being capable of supplying the second gas under the control of the control unit to cure the thin film.

[0020] The control unit can adjust the internal pressure of the process chamber to a first pressure of 0.1 Torr to 20 Torr to supply the first gas, and reduce the pressure inside the process chamber to a second pressure of 0.1 mTorr to 20 mTorr lower than the first pressure to exhaust the bonding product.

[0021] The control unit can also control the heater unit to adjust the temperature inside the process chamber to a temperature of 100°C to 400°C.

[0022] The control unit can perform control to repeatedly supply the first gas, exhaust the bonding product, and supply the second gas multiple times.

[0023] The impurities may include carbon (C), and the first gas may include hydrogen (H).

[0024] The thin film may include a metal element, and the second gas may include oxygen (O).

[0025] [Advantages of the Invention]

[0026] According to the present invention, a method of removing impurities from a thin film can effectively remove impurities from the thin film by reacting the impurities contained in the thin film with a first gas to generate a combined product of the impurities and the first gas and rapidly decompressing the interior of the process chamber to discharge the combined product, and thus the thin film characteristics (e.g., resistivity) can be improved. In addition, by discharging the combined product under a rapidly decreasing pressure from a first pressure of 0.1 Torr to 20 Torr to a second pressure of 0.1 mTorr to 20 mTorr, when the thin film has grooves with a large (or deep) aspect ratio due to a pattern, impurities can be effectively removed from the surface and even the deep part of the grooves of the thin film at a low temperature of 400 °C or less than 400 °C.

[0027] In addition, when defects such as vacancies are generated in a part (or site) where impurities have escaped from the thin film, a second gas different from the first gas can be supplied and the defects can be removed by elements of the second gas to solidify the thin film, thereby improving the reliability of the thin film (or semiconductor device).

[0028] Furthermore, by repeatedly supplying and discharging the first gas and supplying and discharging the second gas multiple times, the removal rate of impurities can be maximized.

[0029] In addition, by forming a solidified layer on the surface of the thin film using the second gas, the solidified layer can inhibit or prevent any reaction between the first gas and elements in the thin film other than impurities. In addition, the solidified layer formed on the surface of the thin film can prevent foreign substances from adhering to the thin film on the substrate unloaded from the process chamber, or prevent the thin film from being oxidized. Description of the Drawings

[0030] Figure 1 is a flowchart showing a method of removing impurities from a thin film according to an embodiment of the present invention.

[0031] Figure 2 is a graph for explaining the cycle of supplying and discharging the first gas and the second gas according to an embodiment of the present invention.

[0032] Figure 3 is a graph for explaining the change in the internal pressure of the process chamber in each step according to an embodiment of the present invention.

[0033] Figure 4 is a schematic cross-sectional view showing a substrate processing apparatus according to another embodiment of the present invention.

[0034] [Description of Symbols]

[0035] 10: Substrate

[0036] 50: External cover

[0037] 100: Substrate processing equipment

[0038] 110: Process chamber

[0039] 111: Outer tube

[0040] 112: Inner tube

[0041] 115: Loading chamber

[0042] 116: Flange portion

[0043] 120: First gas supply unit

[0044] 130: Second gas supply unit

[0045] 140: Heater unit

[0046] 150: Exhaust unit

[0047] 151: Exhaust port

[0048] 152: Exhaust pipe

[0049] 153: Vacuum pump

[0050] 160: Control unit

[0051] 170: Substrate boat

[0052] 171: Rod

[0053] 175: Base

[0054] 175a: Heat insulating plate

[0055] 175b: Support member

[0056] 175c: Upper plate

[0057] 175d: Lower plate

[0058] 175e: Side cover body

[0059] 181: Shaft

[0060] 182: Lifting drive unit

[0061] 183: Rotation drive unit

[0062] 184: Support plate

[0063] 184a: Sealing member

[0064] 184b: Bearing member

[0065] 185: Insertion hole

[0066] 200: Transfer Chamber

[0067] 210: Inlet Port

[0068] 250: Gate Valve

[0069] S100, S200, S300, S400, S500: Steps Detailed Embodiments

[0070] Hereinafter, with reference to the accompanying drawings, embodiments of the present invention will be described in detail. However, the present invention is not limited to these embodiments disclosed below and will be implemented in various forms. Only the embodiments of the present invention are provided to complete the disclosure of the present invention and fully inform those of ordinary skill in the art of the scope of the present invention. Throughout the description, the same reference numerals are assigned to the same elements, the drawings may be partially enlarged in size to accurately illustrate the embodiments of the present invention, and the same reference numerals in the drawings refer to the same elements.

[0071] Figure 1 is a flowchart showing a method for removing impurities in a thin film according to an embodiment of the present invention.

[0072] Referring to Figure 1 , according to an embodiment, the method for removing impurities in a thin film includes the following steps: providing a substrate having a thin film formed thereon in a process chamber (step S100); supplying a first gas that reacts with and binds to the impurities contained in the thin film into the process chamber (step S200); after stopping the supply of the first gas, discharging the combined product of the impurities and the first gas by decompressing the interior of the process chamber (step S300); curing the thin film by supplying a second gas different from the first gas into the process chamber (step S400); and stopping the supply of the second gas and discharging the remaining second gas from the interior of the process chamber (step S500).

[0073] First, a substrate having a thin film formed thereon is provided inside the process chamber (step S100). The thin film may contain impurities, and the substrate having the thin film formed thereon may be loaded (or provided) inside the process chamber to remove these impurities. For example, the substrate may be loaded into the process chamber by a transfer robot. The substrate may be a wafer, and the thin film may be an insulating film (or dielectric film), such as an oxide or nitride or a metal film. For example, a metal precursor compound may be used to deposit the thin film; a metal oxide film or a metal nitride film may be formed by oxidation or nitrification of a metal, or a metal film may be formed by deposition of the metal itself.

[0074] In addition, the thin film may have a pattern. For example, when highly integrated semiconductor devices are fabricated, the thin film can be miniaturized and have a pattern with various structures. The pattern may have a relatively thin thickness and / or a narrow width, or may have a complex shape. Grooves can be formed between the patterns. The grooves can have a large aspect ratio and can be deeper and narrower towards the bottom.

[0075] The process chamber can be of the single-wafer type for processing substrates one by one, or of the batch type for simultaneously processing multiple substrates by loading the multiple substrates in multiple layers on a substrate boat.

[0076] When the process chamber is of the batch type, the step of providing the substrate within the process chamber (step S100) may include the following steps: loading the substrates in multiple layers on the substrate boat; and setting the substrate boat within the process chamber.

[0077] The substrates can be loaded in multiple layers on the substrate boat. The substrate boat may have multi-layered slots formed in multiple rods such that the substrates can be inserted and loaded into the substrate boat. Additionally, the substrate boat may have multi-layered separator plates coupled to the multiple rods. These separator plates can be disposed above or below the substrates such that each substrate can have a separate processing space. The substrate boat can be rotated during the process. As the material of the substrate boat (such as the rods and separator plates), ceramics, quartz, synthetic quartz, etc. can be used; the substrate boat is not limited thereto, but can adopt various structures, shapes, and materials.

[0078] For example, the process chamber can be a process tube (or reaction tube) that receives the substrate boat, and a loading chamber can be provided to communicate with the process chamber below the process chamber. The substrates can be loaded in multiple layers on the substrate boat from the loading chamber by a transfer robot or the like. The process tube can have a single tube or multiple tubes as long as the process tube can provide an internal space (process space) in which the substrate boat can be received. The process tube can be composed of an outer tube and an inner tube, and a flange portion can be coupled to the lower portion of the inner tube to support the inner tube; the inner tube is not limited thereto, but can adopt various structures and shapes.

[0079] The substrate boat can be set within the process chamber. In order to perform an impurity removal process on the thin film formed on the substrate, the substrate boat loaded with the substrate can be set within the process chamber. For example, when the substrate is loaded on the substrate boat, the substrate boat loaded with the substrate can be lifted by a boat elevator to be loaded (or provided) into the interior (space) of the process chamber. The boat elevator can be provided with a sealed top cover including an O-ring, and the O-ring can be attached to the flange portion to seal the lower end of the flange portion. Once the substrate boat is received within the process chamber, an impurity removal process can be performed on the thin film formed on the substrate.

[0080] This batch type process using a susceptor boat can process multiple substrates simultaneously, thereby increasing the throughput of substrates per batch.

[0081] Next, a first gas that reacts with and binds to impurities contained in the thin film is supplied into the process chamber (step S200). The first gas can react with and bind to the impurities contained in the thin film to produce a binding product. In this way, by supplying the first gas into the process chamber and allowing the first gas to react with the impurities in the thin film (e.g., impurities on the surface of the thin film), a first gas binding product can be produced, and the impurities can be removed (separated) from the thin film.

[0082] For example, the impurities may contain carbon, and the first gas may contain hydrogen (H). When depositing a thin film using a metal precursor compound (e.g., an organometallic compound), the bond between the metal element and the carbon ligand is not effectively broken, such that the metal element or an oxide or nitride of the metal element may be deposited together with some of the bonded carbon atoms (C). Thus, carbon is contained in the thin film and acts as an impurity, which may increase the resistivity and / or dielectric constant of the thin film. On the other hand, in some cases, a thin film with a high dielectric constant may be required. In this case, there may be a problem that the dielectric constant of the thin film is reduced due to impurities. Therefore, the impurity carbon must be removed from the thin film. The impurity (carbon) can be removed from the thin film by reacting carbon with the first gas containing hydrogen.

[0083] Hydrogen atoms (H) can react with and bond to carbon atoms (C), and a bonding product of CxHy hydrocarbon (e.g., CH2, CH4, etc.) can be produced through this C - H bond. Since the bonding product CxHy hydrocarbon is in the gas phase, it can be discharged from the process chamber by purging and / or exhausting. The gas containing hydrogen atoms (H) can be hydrogen gas (H2), but is not limited thereto. The gas can be any gas that can react with carbon atoms (C) and provide hydrogen atoms (H) without causing a reaction other than the bonding reaction between hydrogen atoms (H) and carbon atoms (C).

[0084] As the next stage, the supply of the first gas is stopped, and the binding product of the impurities and the first gas is discharged by decompressing the interior of the process chamber (step S300). By decompressing the interior of the process chamber, the binding product of the impurities and the first gas can be discharged. Here, the binding product of the impurities and the first gas can be in the gas phase, and thus can be discharged (emitted) from the process chamber by purging and / or exhausting. When the binding product piles up (or crowds) around the thin film (e.g., on the surface of the thin film), the first gas and / or the second gas do not reach the surface of the thin film (or the exposed surface), and thus cannot react with the impurities and / or the thin film. Therefore, it may no longer be possible to remove the impurities or cure the thin film.

[0085] Therefore, by evacuating the interior of the process chamber to discharge the combined product, it can be ensured that the second gas can react with the thin film, or the first gas can react with impurities in subsequent processes. Therefore, impurities can be effectively removed, and the thin film can be solidified.

[0086] Next, the thin film is solidified by supplying a second gas different from the first gas to the process chamber (step S400). Defects such as vacancies may be generated in the part (or site) where impurities have escaped from the thin film. To improve the quality of the thin film, a second gas different from the first gas can be supplied to solidify the thin film. For example, the vacancies are filled (substituted) with elements of the second gas to remove the defects, thereby improving the quality and reliability of the thin film (or semiconductor device).

[0087] The thin film may contain a metal element (M). The metal element (M) may include any transition metal, such as zinc (Zn), titanium (Ti), tantalum (Ta), chromium (Cr), zirconium (Zr), tungsten (W), nickel (Ni), and copper (Cu), but is not limited thereto. The metal element (M) may be any metal element capable of being deposited as a thin film (such as a metal film, a metal oxide film, or a metal nitride film).

[0088] When an impurity binds to an element of the first gas, the bond between the metal element (M) and the impurity is separated, and the metal element (M) will have dangling bonds (non-bonded sites). For example, when the impurity is a carbon atom (C) and the first gas is hydrogen (H2), the M-C bond is separated by bonding a hydrogen atom (H) and / or a hydrogen molecule (H2) to the carbon atom (C), and the metal element (M) has dangling bonds, thereby forming unnecessary adsorption sites on the thin film. Foreign substances or impurities may be adsorbed or re-adsorbed at the unnecessary adsorption sites.

[0089] This problem can be solved by solidifying the thin film. Unnecessary adsorption sites can be removed by bonding elements of the second gas to the dangling bonds of the metal element (M), and vacancies can be filled with elements of the second gas to remove the defects.

[0090] The step of solidifying the thin film (step S400) may include reacting elements in the second gas with the surface of the thin film to form a solidified layer.

[0091] The elements of the second gas can react with the surface of the thin film to form a solidified layer. The elements of the second gas can react with the surface of the thin film to be adsorbed onto the surface of the thin film (i.e., unnecessary adsorption sites), thereby forming a solidified layer. By removing dangling bonds from the metal element (M), the formation (or generation) of unnecessary adsorption sites can be prevented. In this case, the elements of the second gas can at least partially oxidize or nitride the surface of the thin film, and thus the solidified layer can be an oxidation (oxide) layer or a nitriding (nitride) layer.

[0092] For example, the second gas can contain oxygen (O), and oxygen atoms (O) are bonded to the dangling bonds of the metal element (M) to be adsorbed onto the surface of the thin film, thereby forming a solidified layer. Oxygen can at least partially oxidize the surface of the thin film to form an oxide layer, and thus the solidified layer can be an oxide layer of the metal element (M). For example, the second gas can be a gas containing oxygen atoms (O) or oxygen gas (O2), but is not limited thereto. The gas can be any gas that can provide oxygen atoms (O) that can be bonded to the dangling bonds of the metal element (M).

[0093] The solidified layer can fill the portions where impurities have escaped from the thin film to remove defects, and remove unnecessary adsorption sites to prevent foreign substances or impurities from adsorbing or re-adsorbing onto the surface of the thin film. Therefore, the thin film is passivated, making the thin film stable and improving the reliability of the thin film.

[0094] The solidified layer can have or less than in thickness, for example, in the range of to (i.e., 0.01 nm to 50 nm), to and to (for example, about or less than ). That is to say, the solidified layer can have a thickness of less than one atomic layer to several atomic layers, and can be a discontinuous layer or a continuous layer. Here, the solidified layer with a thickness of less than 1 atomic layer can be a discontinuously formed solidified layer, and the solidified layer with a thickness of 1 atomic layer or more than 1 atomic layer can be a continuously formed solidified layer.

[0095] If the solidified layer becomes thinner than then the portions where impurities have escaped from the thin film cannot be sufficiently filled, and thus it is difficult to effectively remove defects. In addition, the dangling bonds of the metal element (M) and thus unnecessary adsorption sites cannot be sufficiently removed. On the other hand, if the solidified layer exceeds then the elements of the second gas (such as oxygen (O)) become excessive in the entire thin film and the solidified layer, and the electrical characteristics (such as resistivity, conductivity, etc.) of the thin film may deteriorate.

[0096] For example, the thin film may be a zinc oxide (ZnO) film containing carbon (C) as an impurity. When a hydrogen atom (H) of the first gas bonds to the impurity carbon atom (C), the Zn-C bond is separated, thereby forming a dangling bond of zinc (Zn). Then, an oxygen atom (O) of the second gas is bonded (or adsorbed) to the dangling bond of zinc (Zn) to form a zinc oxide (layer). In this case, since the zinc oxide (layer) is homogeneous with the zinc oxide (ZnO) film, the characteristics of the thin film do not deteriorate, and all the dangling bonds of zinc (Zn) are filled, and oxygen (O) deficiency is prevented, so that the characteristics and / or quality of the thin film can be improved.

[0097] On the other hand, when the thin film is a metal nitride film, a second gas containing nitrogen (N) is used, and thus, instead of an oxygen atom (O), a nitrogen atom (N) can be bonded to the dangling bond of a metal element (M) formed by the separation of the M-C bond to form a metal nitride (layer). Even when the thin film is a metal film, oxygen (O2) can also be used as the second gas, and the cured layer will be very thin, as thin as to This not only has little influence on the characteristics (e.g., electrical characteristics) of the thin film, but also can fill the part where impurities have escaped from the thin film to remove defects. Therefore, the thin film is passivated, making the thin film stable and improving the reliability of the thin film.

[0098] In addition, the cured layer can passivate the surface of the thin film to prevent foreign matter from adhering to the thin film on the substrate discharged from the process chamber or the thin film from being oxidized.

[0099] Next, the supply of the second gas is stopped, and the remaining second gas is discharged from the inside of the process chamber (step S500). If the second gas remains (or stays) inside the process chamber, the elements of the second gas can continuously react on the surface of the thin film, so that the elements of the second gas (e.g., oxygen (O)) can become excessive in the thin film, and the cured layer can have a thickness of up to or greater than However, the above problems can be solved by stopping the supply of the second gas and discharging the remaining second gas from the inside of the process chamber to remove the second gas from the inside of the process chamber. In addition, by discharging the remaining second gas from the inside of the process chamber to remove the second gas, when the step of supplying the first gas (step S200) is performed again later, the reaction between the second gas and the first gas can be prevented. In addition, the aggregation of the second gas around the thin film is prevented, so that the first gas can better reach the surface of the thin film and react effectively with impurities.

[0100] Figure 2 is a graph for explaining the cycle of supply and discharge of the first gas and the second gas according to an embodiment of the present invention, andFigure 3 is a graph for explaining the change in the internal pressure of the process chamber in each of the steps according to an embodiment of the present invention.

[0101] Referring to Figure 2 and Figure 3 In the step of supplying the first gas (step S200), the inside of the process chamber is at a first pressure of 0.1 Torr to 20 Torr, and in the step of discharging the combined product (step S300), the inside of the process chamber is depressurized to a second pressure of 0.1 mTorr to 20 mTorr that is lower than the first pressure. The second pressure can be significantly lower than the first pressure, about 1 / 1,000 of the first pressure. That is, in the step of discharging the combined product (step S300), the internal pressure of the process chamber is reduced to about 1 / 1,000 of the pressure in the step of supplying the first gas (step S200), and it can be significantly lower than the pressure in the process of supplying the first gas (step S200). Therefore, the combined product can be effectively discharged from the inside of the process chamber, impurities can be effectively removed from the thin film, and thus the characteristics of the thin film (such as resistivity) can be improved.

[0102] If the first pressure is less than 0.1 Torr, the first gas may not react sufficiently with the impurities, or the elements of the first gas may not have enough energy to combine with the impurities, and the difference from the second pressure may decrease, making it difficult to effectively discharge the combined product from the inside of the process chamber. On the contrary, if the first pressure is greater than 20 Torr, an air flow (or air pressure) may form from the outside into the thin film, making it difficult to separate the impurities from the surface of the thin film (discharging the impurities from the thin film to the outside), and the impurities may not easily migrate from the inside of the thin film to the surface of the thin film.

[0103] If the second pressure is less than 0.1 mTorr, an excessive force (or pressure or air pressure) may be applied to the process chamber, and it may take a long time to return to the first pressure. On the contrary, if the second pressure is greater than 20 mTorr, the difference from the first pressure may decrease, making it difficult to effectively discharge the combined product from the inside of the process chamber.

[0104] As an example, although the first pressure is limited to the range of 0.1 Torr to 20 Torr, and the second pressure is limited to the range of 0.1 mTorr to 20 mTorr, it can be seen that the difference between the first pressure and the second pressure is about 1,000 times the pressure difference within the ranges of the first pressure and the second pressure. That is, the pressure difference is about 1000 times, which is sufficient to enable the combined product to be effectively discharged.

[0105] The step of curing the thin film (step S400) can be carried out at the first pressure, and the step of discharging the remaining second gas (step S500) can be carried out at the second pressure, but it is not particularly limited thereto.

[0106] The step of supplying the first gas (step S200) may be performed for a first time period, and the step of discharging the combined product (step S300) may be performed for a second time period shorter than the first time period. That is, the internal pressure of the process chamber may be rapidly reduced from the (first) pressure in the step of supplying the first gas (step S200) to the pressure in the step of discharging the combined product (step S300). In this case, the internal pressure of the process chamber may be rapidly reduced to about 1 / 1,000 of the pressure in the step of supplying the first gas (step S200). Accordingly, the combined product may be better discharged from the inside of the process chamber. Here, the first time period may be from 4 seconds to 20 seconds and the second time period may be from 2 seconds to 10 seconds. The second time period may be about half of the first time period, but is not limited thereto; it is sufficient if the second time period is shorter than the first time period.

[0107] When forming a pattern in a thin film to form a trench having a large aspect ratio in the thin film, it is difficult to remove impurities from the surface of the thin film (or the exposed surface) deep inside the trench. However, according to the present invention, the combined product may be discharged by rapidly reducing the internal pressure of the process chamber from a first pressure of 0.1 Torr to 20 Torr to a second pressure of 0.1 mTorr to 20 mTorr, and impurities may be effectively removed from the surface of the thin film and even deep inside the trench.

[0108] The step of curing the thin film (step S400) may be performed for the first time period, and the step of discharging the remaining second gas (step S500) may be performed for the second time period, but is not particularly limited thereto.

[0109] Conventionally, heat has been used to process a thin film at a temperature higher than 400°C to transfer energy to impurities for separating (discharging) from the surface of the thin film and removing the impurities from the thin film. In this case, the thermal load or thermal history applied to the substrate and / or the thin film may be a problem. Specifically, due to recent highly integrated semiconductor devices, semiconductor manufacturing processes require a more limited thermal history, and the process of removing impurities also requires implementation at a low temperature of 400°C or less than 400°C. Therefore, the conventional method of removing impurities by high-temperature heat treatment has limitations in its use. To solve this problem, an attempt has been made to perform heat treatment at a high pressure of 2 atmospheres or higher than 2 atmospheres (or 202,650 Pa or higher than 202,650 Pa), whereby the heat treatment temperature may be reduced, but such a method has problems such as an increased risk of gas leakage due to the high pressure, and thus requires a separate device.

[0110] According to the present invention, the process of removing impurities can be carried out at a low pressure of 20 Torr or less than 20 Torr and a low temperature of 400 °C or less than 400 °C, and thus problems such as heat load or thermal history, the risk of gas leakage due to high pressure, and the need for separate devices can be solved. Therefore, impurities can be effectively removed from the thin film even at a low pressure of 20 Torr or less than 20 Torr and a low temperature of 400 °C or less than 400 °C, and even when the thin film has grooves with a large aspect ratio due to the pattern, impurities can be effectively removed from the surface of the thin film and even from the depths of the grooves.

[0111] For example, the step of removing impurities can be carried out at a (process) temperature of 100 °C to 400 °C, and the step of supplying at least the first gas (step S200) can be carried out at a temperature of 100 °C to 400 °C. Here, the temperature of 100 °C to 400 °C can be the temperature inside the process chamber or the temperature of the substrate. If the temperature in the step of supplying the first gas (step S200) is lower than 100 °C, the energy for separating impurities from the surface of the thin film cannot be sufficiently transferred to the impurities, making it difficult to effectively remove the impurities. On the contrary, if the temperature in the step of supplying the first gas (step S200) is higher than 400 °C, the heat load and / or thermal history applied to the substrate and / or the thin film may become a problem.

[0112] In order to transfer sufficient energy to the impurities to discharge the impurities from the thin film to the outside (or separate the impurities from the surface of the thin film), the step of supplying the first gas (step S200) can be carried out at a temperature of 100 °C or higher than 100 °C. In this case, using sufficient energy, the impurities can be easily discharged from the thin film to the outside, and the impurities can be combined with the elements of the first gas (or combined with the elements of the first gas and easily separated from the surface of the thin film), so that the impurities can be removed more effectively. In addition, when the step of supplying the first gas (step S200) is carried out at a temperature of 100 °C or higher than 100 °C, the first gas is activated, and the elements of the first gas are effectively combined with the impurities, so that the impurities can be removed more effectively.

[0113] Even at a temperature lower than 100 °C, impurities can be effectively removed from the surface of the thin film, but the impurities can remain in the thin film. Therefore, by using a temperature of 100 °C or higher than 100 °C to provide energy (i.e., thermal energy) for the impurities to migrate from the thin film to the surface of the thin film, the impurities in the thin film can be effectively (or completely) removed. Even when the thin film has grooves with a large aspect ratio, impurities can be more effectively removed from even the depths of the grooves at a temperature of 100 °C or higher than 100 °C.

[0114] In addition to the step of supplying the first gas (step S200), the step of discharging the combined product (step S300), the step of curing the film (step S400), and the step of discharging the remaining second gas (step S500) can also be carried out at a temperature of 100°C to 400°C. If the step of curing the film (step S400) is carried out at a temperature of 400°C or higher than 400°C, elements of the second gas (such as oxygen (O)) can become excessive in the film, and the cured layer can have a thickness of up to or greater than .

[0115] The step of supplying the first gas (step S200), the step of discharging the combined product (step S300), the step of curing the film (step S400), and the step of discharging the remaining second gas (step S500) can be repeated multiple times. Here, the step of supplying the first gas (step S200), the step of discharging the combined product (step S300), the step of curing the film (step S400), and the step of discharging the remaining second gas (step S500) can be repeated sequentially, otherwise the step of supplying the first gas (step S200) and the step of discharging the combined product (step S300) can be repeated, and subsequently the step of curing the film (step S400) and the step of discharging the remaining second gas (step S500) can be repeated. There is no particular limitation as long as each of the step of supplying the first gas (step S200), the step of discharging the combined product (step S300), the step of curing the film (step S400), and the step of discharging the remaining second gas (step S500) is carried out multiple times.

[0116] By repeating the step of supplying the first gas (step S200), the step of discharging the combined product (step S300), the step of curing the film (step S400), and the step of discharging the remaining second gas (step S500), the supply and discharge of the first gas and the second gas can be repeated multiple times, thereby maximizing the efficiency of removing impurities.

[0117] When the thin film has grooves with a large aspect ratio, at the time after the first gas is supplied, the grooves are filled with the binding product, and the first gas may no longer enter (or be blocked). Therefore, it may not be possible to well remove impurities from the inner wall of the groove (i.e., the surface of the thin film within the groove), and some impurities may remain on the inner wall of the groove. By repeatedly performing at least the step of supplying the first gas (step S200) and the step of discharging the binding product (step S300) multiple times, the binding product filled in the groove can be removed, and the first gas can be introduced into the groove. Therefore, even in the deep part of the groove, impurities can be better removed from the inner wall of the groove, and impurities can be prevented from remaining on the inner wall of the groove. The internal pressure of the process chamber in the step of discharging the binding product (step S300) can be rapidly reduced to about 1 / 1,000 of the pressure in the step of supplying the first gas (step S200). This enables more effective removal of the binding product within the groove.

[0118] On the other hand, when the step of supplying the first gas (step S200), the step of discharging the binding product (step S300), the step of curing the thin film (step S400), and the step of discharging the remaining second gas (step S500) are repeatedly performed multiple times, a cured layer is formed on the surface of the thin film by the second gas, and then the step of supplying the first gas (step S200) is performed again. Any reaction between the first gas and elements other than impurities in the thin film (such as metal elements, oxygen, or nitrogen) can be inhibited or prevented, and defects due to loss or damage of the thin film can also be prevented.

[0119] For example, when the thin film is a metal oxide film, the impurity is carbon (C), and the first gas is hydrogen (H2), when the step of supplying the first gas (step S200) is performed again, the amount of the impurity (i.e., carbon) decreases, and thus in addition to the impurity, the hydrogen atoms (H) of the first gas also react with the oxygen atoms (O) of the metal oxide film, enabling the oxygen atoms (O) to be separated from the thin film. Therefore, oxygen (O) may be depleted in the metal oxide film, which deteriorates the quality and characteristics of the thin film. However, when a cured layer is formed on the surface of the thin film by the second gas containing oxygen atoms (O), the hydrogen atoms (H) of the first gas may react with the oxygen atoms (O) of the cured layer. In addition, the oxygen atoms (O) of the cured layer can be used to supplement the oxygen atoms (O) separated from the thin film. Therefore, the lack of oxygen (O) in the thin film can be prevented, and the quality and characteristics of the thin film can be improved.

[0120] Figure 4 is a schematic cross-sectional view showing a substrate processing apparatus according to another embodiment of the present invention.

[0121] Hereinafter, with reference to Figure 4A substrate processing apparatus according to another embodiment of the present invention will be described in detail, but matters overlapping with those described above regarding the method of removing impurities in a thin film according to an embodiment of the present invention will be omitted.

[0122] According to another embodiment, the substrate processing apparatus 100 includes: a process chamber 110 in which a substrate 10 having a thin film formed thereon is loaded and unloaded; a first gas supply unit 120 configured to supply a first gas into the process chamber 110, the first gas reacting with and bonding to impurities contained in the thin film; a second gas supply unit 130 configured to supply a second gas into the process chamber 110, the second gas being different from the first gas; a heater unit 140 disposed outside the process chamber 110 to provide thermal energy to the interior of the process chamber 110; an exhaust unit 150 configured to exhaust the interior of the process chamber 110; and a control unit 160 configured to control the first gas supply unit 120, the second gas supply unit 130, and the exhaust unit 150 to supply the first gas to generate a bonded product through the reaction of the impurities with the first gas, and then discharge the bonded product, and supply the second gas to cure the thin film.

[0123] The substrate 10 having a thin film formed thereon can be loaded and unloaded in the process chamber 110. The process chamber 110 can be of a single-wafer type for processing substrates one by one, or a batch type for simultaneously processing a plurality of substrates 10 by loading the plurality of substrates 10 in a multi-layer on a substrate boat 170.

[0124] When the process chamber 110 is of the batch type, the substrate processing apparatus 100 according to the present invention may further include a substrate boat 170 on which the substrates 10 are loaded in a multi-layer, and the process chamber 110 may have an internal space for receiving the substrate boat 170.

[0125] The substrate boat 170 may have multi-layered slots formed in a plurality of rods 171 such that the substrates 10 can be inserted and loaded into the substrate boat 170. Additionally, the substrate boat 170 may have multi-layered separator plates (not shown) coupled to the plurality of rods 171. These separator plates (not shown) may be disposed above or below the substrates 10 such that each substrate 10 can have a separate processing space. The substrate boat 170 can be rotated during the process. As materials for the substrate boat 170 (e.g., the rods 171 and the separator plates (not shown)), ceramics, quartz, synthetic quartz, etc. can be used; the substrate boat is not limited thereto, but various structures, shapes, and materials can be adopted.

[0126] The process chamber 110 may have an internal space (i.e., a process space) in which a susceptor 170 is received, and may provide a space for performing an impurity removal process on a thin film formed on the substrate 10. For example, the process chamber 110 may be a process tube (or reaction tube) that receives the susceptor 170, and the load chamber 115 may be provided to communicate with the process chamber 110 below the process chamber 110. The substrate 10 may be loaded on the susceptor 170 in multiple layers from the load chamber 115 by a transfer robot or the like. The process tube may have a single tube or multiple tubes as long as the process tube can provide an internal space (process space) in which the susceptor 170 can be received. The process tube may be composed of an outer tube 111 and an inner tube 112, and a flange portion 116 may be coupled to a lower portion of the inner tube 112 to support the inner tube 112; the inner tube 112 is not limited thereto, but may adopt various structures and shapes.

[0127] In such a batch type process using the susceptor 170, multiple substrates 10 can be processed simultaneously, thereby increasing the throughput of the substrates 10 per batch.

[0128] The first gas supply unit 120 may supply a first gas that reacts with and binds to impurities contained in the thin film within the process chamber 110, and the first gas may react with and bind to the impurities contained in the thin film to generate a binding product.

[0129] The second gas supply unit 130 may supply a second gas different from the first gas within the process chamber 110, and the second gas may solidify the thin film and remove at least some of the impurities from the thin film.

[0130] The first gas supply unit 120 and the second gas supply unit 130 may be provided on one side of the inner tube 112. The first gas supply unit 120 and the second gas supply unit 130 may supply the first gas and the second gas within the process chamber 110 through a plurality of different injection nozzles, respectively. Otherwise, the first gas and the second gas may be temporarily separated and supplied through one injection nozzle. When using one injection nozzle, a purge gas may be supplied to the injection nozzle by a purge gas supply unit (not shown). For example, the purge gas may be supplied to the injection nozzle between the supply of the first gas and the supply of the second gas, and the remaining gas of the first gas or the remaining gas of the second gas may be purged within the injection nozzle. The purge gas may include nitrogen (N2) or any inert gas such as argon (Ar), helium (He), neon (Ne), etc.

[0131] The heater unit 140 can be disposed outside the process chamber 110 and provide thermal energy inside the process chamber 110. For example, the heater unit 140 can extend vertically outside the inner tube 112 to heat the inner tube 112. The heater unit 140 can be arranged to surround the side and upper portions of the inner tube 112 or the outer tube 111, or can be disposed on the inner wall of the outer cover 50 covering the outer tube 111. The heater unit 140 can adjust the temperature inside the process chamber 110. The temperature inside the process chamber 110 can be adjusted to 100°C to 400°C.

[0132] The exhaust unit 150 can evacuate the interior of the process chamber 110, adjust the internal pressure of the process chamber 110, and evacuate the reaction product between the first gas and the impurities as well as the residual gases of the first gas and the second gas. The exhaust unit 150 can be disposed on the other side of the inner tube 112 opposite to one side of the inner tube 112, and the reaction product and the residual gases in the inner tube 112 can be discharged (removed). Here, when the first gas supply unit 120 and the second gas supply unit 130 are positioned to face (or be symmetric to) the exhaust unit 150, a laminar flow can be formed on the substrate 10.

[0133] The control unit 160 can control the first gas supply unit, the second gas supply unit, and the exhaust unit to supply the first gas to generate a reaction product by reacting with the impurities, and then discharge the reaction product, and supply the second gas to cure the thin film. Additionally, the control unit 160 can control the first gas supply unit 120, the second gas supply unit 130, and the exhaust unit 150 to adjust the supply of the first gas, the supply of the second gas, and the internal pressure of the process chamber so that impurities can be removed from the thin film.

[0134] For example, the control unit 160 can control the first gas supply unit 120 to perform a first process (in the first process, the first gas is supplied and reacts with the impurities), and control the exhaust unit 150 to perform a second process (in the second process, the interior of the process chamber is depressurized to discharge the reaction product between the impurities and the first gas). Additionally, the control unit 160 can control the second gas supply unit 130 to perform a third process (in the third process, the second gas is supplied to cure the thin film), and control the exhaust unit 150 to perform a fourth process (in the fourth process, the remaining second gas is discharged from the interior of the process chamber 110). During the first process, the first gas is supplied and reacts with the impurities to generate a reaction product between the impurities and the first gas, and during the second process, the interior of the process chamber 110 is depressurized to discharge the reaction product. Thus, impurities can be effectively removed from the thin film.

[0135] During the third process, a second gas is supplied to cure the thin film, and during the fourth process, the remaining second gas is exhausted from the interior of the process chamber 110. Accordingly, the portion from which impurities have escaped from the thin film can be filled with elements of the second gas to remove defects, thereby improving the quality and reliability of the thin film.

[0136] The control unit 160 can supply a first gas (during the first process) inside the process chamber 110 at a first pressure of 0.1 Torr to 20 Torr, and discharge the combined product by reducing the pressure inside the process chamber 110 to a second pressure of 0.1 mTorr to 20 mTorr (during the second process) that is lower than the first pressure.

[0137] The combined product can be discharged by rapidly reducing the internal pressure of the process chamber from a first pressure of 0.1 Torr to 20 Torr to a second pressure of 0.1 mTorr to 20 mTorr, and impurities can be effectively removed from the surface of the thin film and even from the depths of the trenches.

[0138] For example, the exhaust unit 150 can include: an exhaust port 151 provided at one side of the process chamber 110; an exhaust pipe 152 connected to the exhaust port 151; and a vacuum pump 153 connected to the exhaust pipe 152. The exhaust port 151 can communicate with the lower portion of an exhaust duct, and thus introduce waste gas from the exhaust port 151 communicating with the exhaust duct and transfer it through the exhaust port 151 to the exhaust pipe 152 for discharge to the outside.

[0139] The exhaust pipe 152 can be connected to the exhaust port 151 to provide an exhaust path between the exhaust port 151 and the vacuum pump 153.

[0140] The vacuum pump 153 can be connected to the exhaust pipe 152 to provide an exhaust pressure for discharging waste gas (i.e., the combined product and the remaining gas of the first gas and / or the second gas) and evacuate the interior of the process chamber 110 in a vacuum state.

[0141] Here, under the condition that the vacuum pump 153 is operating, the opening and closing degree of an auto pressure controller (APC) valve (not shown) can be adjusted based on the pressure information detected by a pressure sensor (not shown), thereby adjusting the internal pressure of the process chamber 110.

[0142] The exhaust pipe 152 can have an inner diameter of 50 mm to 200 mm (or a size of 100 A or greater than 100 A) and a size of 200 A or greater than 200 A, where A is a unit representing area, and 1 A is 100 square centimeters (cm 2) Thus, the exhaust performance of the exhaust unit 150 can be improved, and the internal pressure of the process chamber 110 can be rapidly reduced from a first pressure of 0.1 Torr to 20 Torr to a second pressure of 0.1 mTorr to 20 mTorr. The maximum exhaust rate of the vacuum pump 153 can be 50 kl / s to 200 kl / s. In a general substrate processing apparatus using a vacuum pump with a maximum exhaust rate of less than 50 kl / s, the internal pressure of the process chamber 110 cannot be reduced to a pressure of 0.1 mTorr to 20 mTorr. However, according to the present invention, in the substrate processing apparatus 100 using the vacuum pump 153 with a maximum exhaust rate of 50 kl / s to 200 kl / s, the internal pressure of the process chamber 110 can be reduced to a pressure of 0.1 mTorr to 20 mTorr.

[0143] The impurities may include carbon, and the first gas may include hydrogen (H). When a metal precursor compound (e.g., an organometallic compound) is used to deposit a thin film, the bond between the metal element and the carbon ligand is not effectively broken, such that the metal element or an oxide or nitride of the metal element may be deposited together with some of the bonded carbon atoms (C). Thus, carbon is included in the thin film and acts as an impurity, which may increase the resistivity and / or dielectric constant of the thin film. Therefore, the impurity carbon must be removed from the thin film. The impurity (carbon) can be removed from the thin film by reacting carbon with the first gas containing hydrogen.

[0144] The thin film may include a metal element (M), and the second gas may include oxygen (O). Since the thin film may include a metal element (M), when the impurity binds to the element of the first gas, the bond between the metal element (M) and the impurity is separated, and the metal element (M) will have a dangling bond (non-bonded site). At the same time, the second gas may include oxygen (O), and the oxygen atom (O) bonds to the dangling bond of the metal element (M) to be adsorbed onto the surface of the thin film, thereby forming a cured layer.

[0145] In addition, the control unit 160 can control the heater unit 140 to adjust the temperature within the process chamber 110 to a temperature of 100°C to 400°C. That is, the impurity removal process can be carried out at a temperature of 100°C to 400°C, and by controlling the supply of the first gas by the heater unit 140 (during the first process), at least the interior of the process chamber 110 can be adjusted to a temperature of 100°C to 400°C. The substrate processing apparatus 100 according to the present invention can carry out the impurity removal process through a large pressure difference and rapid decompression even at a low temperature of 400°C or less than 400°C, and thus can solve problems such as heat load or heat history. That is, even at a low temperature of 400°C or less than 400°C, impurities can be effectively removed from the thin film, and even in the case where the thin film has trenches with a large aspect ratio due to patterns, impurities can be effectively removed from the surface of the thin film and even from the depths of the trenches.

[0146] The control unit 160 may repeatedly perform the supply of the first gas, the discharge of the combined product, and the supply of the second gas multiple times. For example, the control unit 160 may repeatedly perform the first process, the second process, the third process, and the fourth process in this order. By repeating the supply of the first gas, the discharge of the combined product, and the supply of the second gas, the efficiency of removing impurities can be maximized, and the removal rate can also be maximized.

[0147] By repeatedly performing the supply of the first gas and the discharge of the combined product multiple times, the combined product filled in the trench can be removed, and the first gas can be introduced into the trench. Therefore, even in the deep part of the trench, impurities can be better removed from the inner wall of the trench, and impurities can be prevented from remaining on the inner wall of the trench.

[0148] According to the present invention, the substrate processing apparatus 100 may further include a base 175 connected to the lower end of the substrate boat 170 to support the substrate boat 170. The base 175 is connected to the lower end of the substrate boat 170 to support the substrate boat 170. The base 175 may also rise and fall together with the substrate boat 170 and may be accommodated in a space that receives the inner tube 112 during the process. The base 175 may include a plurality of heat barrier plates 175a spaced apart from each other and arranged in multiple layers. The plurality of heat barrier plates 175a may be connected to a plurality of support members 175b, and the plurality of heat barrier plates 175a may be provided in multiple layers and spaced apart from each other. The plurality of heat barrier plates 175a may include baffle plates for preventing heat transfer in the vertical direction and may be formed of a material having a low heat transfer rate (e.g., opaque quartz).

[0149] In addition, the base 175 may further include: the plurality of support members 175b extending in the vertical direction and spaced apart from each other; an upper plate 175c and a lower plate 175d to which the upper ends and the lower ends of the plurality of support members 175b are fixed; and a side cover 175e surrounding the sides of the plurality of heat barrier plates 175a (or the sides of the base). The plurality of support members 175b may extend in the vertical direction and be arranged to be spaced apart from each other in the horizontal direction. The plurality of support members 175b may also support the plurality of heat barrier plates 175a.

[0150] The upper plate 175c may fix the upper ends of the plurality of support members 175b and may be connected to the substrate boat 170. The lower plate 175d may fix the lower ends of the plurality of support members 175b and may be connected to the shaft 181. The plurality of support members 175b, the upper plate 175c, and the lower plate 175d may form a skeleton (or frame) of the base 175.

[0151] The side cover 175e can be formed to surround the sides of the plurality of heat insulating plates 175a (or the sides of the base), and can be connected to the upper plate 175c and / or the lower plate 175d to fix the upper plate 175c and / or the lower plate 175d.

[0152] According to the present invention, the substrate processing apparatus 100 may further include: a shaft 181 connected to the lower plate 175d of the base 175; a lifting drive unit 182 connected to the lower end of the shaft 181 to move the shaft 181 up and down; a rotation drive unit 183 connected to the lower end of the shaft 181 to rotate the shaft 181; a support plate 184 connected to the upper end of the shaft 181 and configured to move up and down together with the substrate carrier 170; a sealing member 184a provided between the inner tube 112 or the outer tube 111 and the support plate 184; a bearing member 184b provided between the support plate 184 and the shaft 181; and an insertion hole 185 through which the substrate 10 is loaded into the loading chamber 115.

[0153] The shaft 181 can be connected to the lower plate 175d of the base 175 to support the base 175 and / or the substrate carrier 170.

[0154] The lifting drive unit 182 can be connected to the lower end of the shaft 181 to move the shaft 181 up and down, thereby moving the substrate carrier 170 up and down.

[0155] The rotation drive unit 183 can be connected to the lower end of the shaft 181 to rotate the substrate carrier 170. The rotation drive unit 183 can also rotate the shaft 181, and thus rotate the substrate carrier 170 around the shaft 181.

[0156] The support plate 184 can be connected to the upper end of the shaft 181 to move up and down together with the substrate carrier 170. When the substrate carrier 170 is accommodated in the space that receives the inner tube 112, it can also function to seal the space that receives the inner tube 112 from the outside and / or the inner space of the outer tube 111.

[0157] The sealing member 184a can be provided between the support plate 184 and the inner tube 112 and / or between the support plate 184 and the outer tube 111 to seal the space that receives the inner tube 112 and / or the inner space of the outer tube 111.

[0158] The bearing member 184b can be provided between the support plate 184 and the shaft 181 to rotate the shaft 181 supported by the bearing member 184b.

[0159] The insertion hole 185 may be provided on one side of the loading chamber 115, and the substrate 10 may be loaded into the loading chamber 115 from the transfer chamber 200 through the insertion hole 185. The inlet port 210 may be formed on one side of the transfer chamber 200 corresponding to the insertion hole 185 of the loading chamber 115, and the gate valve 250 may be provided between the inlet port 210 and the insertion hole 185. Accordingly, the interior of the transfer chamber 200 may be separated from the interior of the loading chamber 115 by the gate valve 250, and the inlet port 210 and the insertion hole 185 may be opened and closed by the gate valve 250.

[0160] As described above, the present invention can effectively remove impurities from the thin film by reacting the impurities contained in the thin film with the first gas to generate a combined product of the impurities and the first gas and rapidly decompressing the interior of the process chamber to discharge the combined product, and thus the characteristics of the thin film (e.g., resistivity) can be improved. In addition, by discharging the combined product under a rapidly decreasing pressure from a first pressure of 0.1 Torr to 20 Torr to a second pressure of 0.1 mTorr to 20 mTorr, when the thin film has grooves with a large (or deep) aspect ratio due to the pattern, the impurities can be effectively removed from the surface and even the deep part of the grooves of the thin film at a low temperature of 400 °C or less than 400 °C.

[0161] In addition, when defects such as vacancies are generated in a part (or site) where impurities have escaped from the thin film, a second gas different from the first gas may be supplied, and the defects can be removed by the elements of the second gas to solidify the thin film, thereby improving the reliability of the thin film.

[0162] Furthermore, by repeatedly supplying and discharging the first gas and supplying and discharging the second gas multiple times, the removal rate of impurities can be maximized.

[0163] In addition, by forming a solidified layer on the surface of the thin film using the second gas, the solidified layer can inhibit or prevent any reaction between the first gas and elements other than impurities in the thin film. In addition, the solidified layer formed on the surface of the thin film can prevent foreign substances from adhering to the thin film on the substrate unloaded from the process chamber, or prevent the thin film from being oxidized.

[0164] As described above, although the preferred embodiments of the present invention have been shown and described, the present invention is not limited to the above embodiments, and it should be understood that those skilled in the art to which the present invention pertains can have various modifications and equivalents without departing from the scope of the present invention stated in the claims. Therefore, the technical protection scope of the present invention should be limited only by the above claims.

Claims

1. A method for removing impurities in a thin film, the method comprising the following steps: Providing a substrate having the thin film formed thereon in a process chamber; Supplying a first gas that reacts with and binds to the impurities contained in the thin film into the process chamber; After stopping the supply of the first gas, discharging the combined product of the impurities and the first gas by decompressing the interior of the process chamber; Curing the thin film by supplying a second gas different from the first gas into the process chamber; And Stopping the supply of the second gas and discharging the remaining second gas from the interior of the process chamber, wherein the step of supplying the first gas is carried out at a first pressure of 0.1 Torr to 20 Torr within the process chamber, and the step of supplying the first gas is carried out for a first time period, and the step of discharging the combined product is carried out at a second pressure of 0.1 mTorr to 20 mTorr lower than the first pressure by decompressing the interior of the process chamber, and the step of discharging the combined product is carried out for a second time period shorter than the first time period.

2. The method according to claim 1, wherein the impurities contain carbon and the first gas contains hydrogen.

3. The method according to claim 1, wherein the thin film contains a metal element and the second gas contains oxygen.

4. The method according to claim 1, wherein the step of supplying the first gas is carried out at a temperature of 100 °C to 400 °C.

5. The method according to claim 1, wherein the step of curing the thin film includes reacting the elements of the second gas with the surface of the thin film to form a cured layer.

6. The method according to claim 5, wherein the cured layer has or less than a thickness of.

7. The method according to claim 1, wherein the steps of supplying the first gas, discharging the combined product, curing the thin film, and discharging the remaining second gas are repeated multiple times.

8. A substrate processing apparatus, comprising: A process chamber in which a substrate having a thin film formed thereon is loaded and unloaded; A first gas supply unit configured to supply a first gas into the process chamber, the first gas reacting with and binding to the impurities contained in the thin film; A second gas supply unit configured to supply a second gas into the process chamber, the second gas being different from the first gas; A heater unit disposed outside the process chamber to provide heat energy to the interior of the process chamber; An exhaust unit configured to exhaust the interior of the process chamber; And A control unit configured to control the first gas supply unit, the second gas supply unit, and the exhaust unit, wherein the first gas supply unit supplies the first gas under the control of the control unit to generate a combined product through the reaction of the impurities and the first gas, the exhaust unit discharges the combined product under the control of the control unit, and the second gas supply unit supplies the second gas under the control of the control unit to cure the thin film, The control unit adjusts the internal pressure of the process chamber to a first pressure of 0.1 Torr to 20 Torr to supply the first gas, and the step of supplying the first gas is carried out for a first time period. The control unit reduces the internal pressure of the process chamber to a second pressure of 0.1 mTorr to 20 mTorr that is lower than the first pressure to discharge the combined product, and the step of discharging the combined product is carried out for a second time period that is shorter than the first time period.

9. The substrate processing apparatus according to claim 8, wherein the control unit further controls the heater unit to adjust the temperature within the process chamber to a temperature of 100 °C to 400 °C.

10. The substrate processing apparatus according to claim 8, wherein the control unit controls to repeatedly carry out the step of supplying the first gas, the step of discharging the combined product, and the step of supplying the second gas multiple times.

11. The substrate processing apparatus according to claim 8, wherein the impurity contains carbon and the first gas contains hydrogen.

12. The substrate processing apparatus according to claim 8, wherein the thin film contains a metal element and the second gas contains oxygen.

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