Substrate processing method

Abstract

The present invention relates to a substrate processing method, and more particularly, to a substrate processing method for improving the physical properties of a thin film formed on a substrate. One embodiment of the substrate processing method of the present invention includes: a step of transporting a substrate into a first chamber; a first pressurizing step of increasing the pressure in the first chamber to increase the pressure in the first chamber to a first high pressure higher than atmospheric pressure; a first depressurizing step of decreasing the pressure in the first chamber to decrease the pressure in the first chamber to a second high pressure lower than the first high pressure and above atmospheric pressure; a first pressure-increasing and pressure-decreasing repetitive step of repeatedly performing the first pressurizing step and the first depressurizing step a predetermined number of times; and a second depressurizing step of decreasing the pressure in the first chamber to decrease the pressure in the first chamber to a first low pressure lower than atmospheric pressure.

Description

Technical Field

[0001] The present invention relates to a substrate processing method, and more particularly, to a substrate processing method for improving the physical properties of a thin film formed on a substrate. Background Art

[0002] Typically, semiconductor devices are manufactured by depositing and etching various thin films. Thin films are deposited using various methods, such as physical vapor deposition (PVD), chemical vapor deposition (CVD), and atomic layer deposition (ALD). However, each method uses different process temperatures, pressures, and gases, resulting in the deposited thin films often not meeting the desired physical properties.

[0003] In order to improve this situation, a method of improving the physical properties of a thin film by post-treatment after thin film deposition is being used. Various methods such as heat treatment and plasma treatment are being used for post-treatment.

[0004] On the other hand, semiconductor devices with high aspect ratios, such as 3D NAND flash memory devices or DRAM capacitors, require excellent step coverage, and therefore often utilize low-temperature processes or precursors with high impurity contents. However, this increases the impurity content in the deposited thin film, making it more difficult to form a thin film with desired physical properties (resistivity, composition ratio, density, etc.). Consequently, new substrate processing methods are being sought that can improve the physical properties of the thin film through post-processing after thin film deposition. Summary of the Invention

[0005] Problem to be solved

[0006] The present invention has been made to solve the above-mentioned conventional problems, and an object of the present invention is to provide a substrate processing method capable of improving the physical properties of a thin film formed on a substrate.

[0007] Means of solving the problem

[0008] An embodiment of the substrate processing method of the present invention for solving the above-mentioned technical problems includes: a step of transporting the substrate into a first chamber; a first pressurizing step of increasing the pressure in the first chamber so that the pressure in the first chamber reaches a first high pressure higher than normal pressure; a first pressure reducing step of reducing the pressure in the first chamber so that the pressure in the first chamber reaches a second high pressure lower than the first high pressure and above normal pressure; a first pressure increasing and reducing repetitive step of repeatedly performing the first pressurizing step and the first pressure reducing step a predetermined number of times; and a second pressure reducing step of reducing the pressure in the first chamber so that the pressure in the first chamber reaches a first low pressure lower than normal pressure.

[0009] In some embodiments of the substrate processing method of the present invention, when the second high pressure is greater than atmospheric pressure, the second pressure reducing step includes: a second-first pressure reducing step of reducing the pressure in the first chamber to atmospheric pressure; and a second-second pressure reducing step of reducing the pressure in the first chamber to the first low pressure. When the second high pressure is atmospheric pressure, the second pressure reducing step may include a second-second pressure reducing step of reducing the pressure in the first chamber to the first low pressure.

[0010] In some embodiments of the substrate processing method of the present invention, the second depressurization step may include a first normal pressure maintaining step of maintaining normal pressure for a predetermined time before the second depressurization step.

[0011] In some embodiments of the substrate processing method of the present invention, the first normal pressure maintaining step may include supplying a purge gas.

[0012] In some embodiments of the substrate processing method of the present invention, a first low-pressure maintaining step of maintaining the first low pressure for a predetermined time may be included after the second pressure reducing step.

[0013] In some embodiments of the substrate processing method of the present invention, a first high-pressure maintaining step of maintaining the first high pressure for a predetermined time is included between the first pressurization step and the first pressure reduction step; the first pressure increase and reduction repeated execution step can repeatedly execute the first pressurization step, the first high-pressure maintaining step and the first pressure reduction step several times in sequence.

[0014] In some embodiments of the substrate processing method of the present invention, the first pressurizing step is performed under a first gas environment, and after the second pressurizing step, it may include: a second pressurizing step of increasing the pressure in the first chamber under a second gas environment different from the first gas, so that the pressure in the first chamber reaches a third high pressure higher than normal pressure; a third pressurizing step of reducing the pressure in the first chamber, so that the pressure in the first chamber reaches a fourth high pressure lower than the third high pressure and above normal pressure; a second pressurizing and reducing repetitive execution step of repeatedly executing the second pressurizing step and the third pressurizing step a predetermined number of times; and a fourth pressurizing step of reducing the pressure in the first chamber, so that the pressure in the first chamber reaches a second low pressure lower than normal pressure.

[0015] In some embodiments of the substrate processing method of the present invention, the first pressurization step is performed in a first gas environment, and after the second pressurization step, it may include: a step of transporting the substrate out of the first chamber; a step of transporting the substrate into a second chamber; increasing the pressure in the second chamber under a second gas environment different from the first gas, so that the pressure in the second chamber reaches a third high pressure higher than normal pressure; a third pressurization step of reducing the pressure in the second chamber, so that the pressure in the second chamber reaches a fourth high pressure lower than the third high pressure and above normal pressure; a second pressurization and depressurization repetition step of repeatedly performing the second pressurization step and the third pressurization step a predetermined number of times; and a fourth pressurization step of reducing the pressure in the second chamber, so that the pressure in the second chamber reaches a second low pressure lower than normal pressure.

[0016] In some embodiments of the substrate processing method of the present invention, a second low-pressure maintaining step of maintaining the second low pressure for a predetermined time may be included after the fourth pressure reducing step.

[0017] In some embodiments of the substrate processing method of the present invention, when the fourth high pressure is higher than normal pressure, the fourth pressure reducing step includes: a fourth-first pressure reducing step of reducing the pressure in the first chamber to normal pressure; and a fourth-second pressure reducing step of reducing the pressure in the first chamber to the second low pressure. When the fourth high pressure is normal pressure, the fourth pressure reducing step may include a fourth-second pressure reducing step of reducing the pressure in the first chamber to the second low pressure.

[0018] In some embodiments of the substrate processing method of the present invention, when the fourth high pressure is higher than atmospheric pressure, the fourth pressure reducing step includes: a fourth-first pressure reducing step of reducing the pressure in the second chamber to atmospheric pressure; and a fourth-second pressure reducing step of reducing the pressure in the second chamber to the second low pressure. When the fourth high pressure is atmospheric pressure, the fourth pressure reducing step may include a fourth-second pressure reducing step of reducing the pressure in the second chamber to the second low pressure.

[0019] In some embodiments of the substrate processing method of the present invention, the fourth depressurization step is a second normal pressure maintaining step that may include maintaining the normal pressure for a predetermined time before the fourth-second depressurization step.

[0020] In some embodiments of the substrate processing method of the present invention, the second normal pressure maintaining step may include supplying a purge gas.

[0021] In some embodiments of the substrate processing method of the present invention, a second high-pressure maintaining step is included between the second pressure-increasing step and the third pressure-decreasing step, wherein the third high pressure is maintained for a predetermined time. The second pressure-increasing and pressure-decreasing repetitive step is performed by repeatedly performing the second pressure-increasing step, the second high-pressure maintaining step, and the third pressure-decreasing step a predetermined number of times.

[0022] In some embodiments of the substrate processing method of the present invention, the first gas may be a gas containing at least one of hydrogen (H), oxygen (O), nitrogen (N), chlorine (Cl), and fluorine (F).

[0023] The second gas may be a gas including at least one of hydrogen (H), oxygen (O), nitrogen (N), chlorine (Cl), and fluorine (F).

[0024] In some embodiments of the substrate processing method of the present invention, a thin film may be formed on the substrate.

[0025] In some embodiments of the substrate processing method of the present invention, the thin film may constitute at least a portion of a gate insulating film of a transistor.

[0026] In some embodiments of the substrate processing method of the present invention, the thin film may contain at least one of metal elements, Group IV elements, III-V compounds, II-VI compounds, nitrogen (N), oxygen (O), and boron (B).

[0027] Effects of the Invention

[0028] According to the present invention, after thin film formation, the pressure is increased and then rapidly decreased, thereby removing impurities from the film and improving film properties. Specifically, the present invention removes impurities from the film by repeatedly increasing and decreasing the pressure above atmospheric pressure, significantly shortening the process time while also improving electrical properties. Furthermore, by shortening the process time, the heat treatment time is shortened, thereby reducing the thermal budget.

[0029] In addition, the substrate processing method of the present invention can also uniformly process 3D semiconductor devices or devices with a high aspect ratio, and is performed through an independent process, so it is applicable to a wide range of substrate processing methods.

[0030] Then, the substrate processing method of the present invention is performed before forming a thin film, which can improve the surface properties of the substrate, and is performed when forming a thin film, which can also improve the properties of the thin film.

[0031] Furthermore, the substrate treatment method of the present invention effectively removes impurities, thereby improving thin film properties through a relatively lower temperature and energy heat treatment process compared to conventional high-temperature or high-energy heat treatment processes. In particular, by maintaining the reduced pressure for a predetermined period, the impurity removal effect is enhanced. Furthermore, in the case of nitride films, the addition of a pressure increase / depressurization step in a nitrogen (N)-containing gas atmosphere increases the nitrogen (N) content within the film, thereby improving oxidation resistance. BRIEF DESCRIPTION OF THE DRAWINGS

[0032] Figure 1 A flow chart showing an execution process of an embodiment of a substrate processing method of the present invention is shown.

[0033] Figure 2a and Figure 2b This is a diagram schematically showing pressure changes inside a first chamber according to one embodiment of a thin film processing method of the present invention; Figure 2a is a diagram showing pressure changes in a case where the second high pressure is greater than normal pressure; Figure 2b Graph showing pressure changes when the second high pressure is normal pressure.

[0034] Figures 3 to 5 This is a schematic diagram for explaining the execution of the pressure increasing step and the pressure decreasing step.

[0035] Figure 6 Graphs showing the improvement effect of the present invention on electrical properties and graphs showing changes in sheet resistance before and after heat treatment.

[0036] Figure 7 This is a diagram schematically showing pressure changes in the first chamber of a conventional thin film processing method.

[0037] Figure 8FIG. 1 is a flowchart illustrating an execution process of another embodiment of a substrate processing method according to the present invention.

[0038] Figure 9 This is a schematic diagram for explaining the case where a pressure increasing step and a pressure decreasing step are performed under a first gas environment and then a pressure increasing step and a pressure decreasing step are performed under a second gas environment.

[0039] Figure 10 This is a flowchart showing the execution process of another embodiment of the substrate processing method of the present invention. DETAILED DESCRIPTION

[0040] The following describes embodiments of the present invention in detail with reference to the accompanying drawings. These embodiments are provided to more fully illustrate the present invention to those skilled in the art. The following embodiments may be modified in various ways, and the scope of the present invention is not limited to the following embodiments. Rather, these embodiments are provided to provide a more realistic and complete disclosure and to fully convey the concepts of the present invention to those skilled in the art.

[0041] In the drawings, variations in the shapes shown are predictable, for example, due to manufacturing techniques and / or tolerances. Thus, embodiments of the present invention should not be construed as limited to the specific shapes of the regions shown in this specification, but should include variations in shape caused by, for example, manufacturing. Identical reference numerals always refer to identical elements. Furthermore, various elements and regions are generally depicted in the drawings. Therefore, the present invention is not limited to the relative sizes or spacings shown in the drawings.

[0042] Figure 1 A flow chart showing an execution process of an embodiment of a substrate processing method of the present invention is shown. Figure 2a and Figure 2b This is a diagram schematically showing pressure changes inside a first chamber according to one embodiment of a thin film processing method of the present invention; Figure 2a is a diagram showing pressure changes in a case where the second high pressure is greater than normal pressure; Figure 2b Graph showing pressure changes when the second high pressure is normal pressure.

[0043] Reference Figure 1 、 Figure 2a and Figure 2b In one embodiment of the substrate processing method of the present invention, a substrate is first placed into a first chamber (S100). The substrate can be made of silicon, silicon oxide, silicon nitride, silicon carbide, graphite, graphene, a III-V compound, a II-VI compound, or the like, without particular limitation. The first chamber can be a chamber capable of increasing and decreasing pressure, and is equipped with gas supply means, heating means, pump means, a high-pressure valve, and the like.

[0044] The substrate may be formed with a thin film, and the thin film formed on the substrate may be a thin film that constitutes at least a portion of the gate insulating film of the transistor. In addition, the thin film formed on the substrate may contain at least one of a metal element, a group IV element, a III-V compound, a II-VI compound, nitrogen (N), oxygen (O), and boron (B), for example, a thin film composed of silicon, silicon oxide, silicon nitride, metal oxide, metal nitride, III-V compound, II-VI compound, ternary compound, and quaternary compound. Then, there is no particular restriction on the method for forming the thin film. The thin film can be formed by physical vapor deposition (PVD), chemical vapor deposition (CVD), atomic layer deposition (ALD), etc., and there is no particular restriction on the process temperature or process pressure.

[0045] The thin film formed on the substrate can be a nitride thin film, or a metal nitride thin film. More specifically, it can be a titanium nitride (TiN) thin film. To form the metal nitride thin film, chemical vapor deposition or atomic layer deposition can be used. In this case, a halogen-containing metal precursor can be used as the metal precursor, and a nitrogen-containing gas can be used as the reaction gas. For example, a titanium nitride (TiN) thin film can be formed by atomic layer deposition using a titanium tetrachloride (TiCl4) precursor and nitrogen (N2) or ammonia (NH3) reaction gas.

[0046] Then, the pressure in the first chamber is increased so that the pressure in the first chamber reaches a first high pressure (first pressurizing step S110). The first high pressure is a pressure above normal pressure, which can be a pressure of about 1 to 30 atm. The first pressurizing step S110 can be performed under a first gas environment, and can be performed in a state where the inside of the first chamber is heated. The first gas can contain at least one of hydrogen (H), oxygen (O), nitrogen (N), chlorine (Cl) and fluorine (F), and the best gas can be selected according to the type of thin film formed on the substrate. For example, the first gas can utilize a reducing gas, and a gas containing hydrogen (H) can be utilized. More specifically, hydrogen (H2) gas can be utilized. In addition, in order to perform an oxidation heat treatment for an oxidized film, oxygen (O2) gas can be utilized as the first gas. The temperature in the first chamber can be selected to be the best temperature according to the type of thin film formed on the substrate.

[0047] Then, the pressure in the first chamber is maintained at a first high pressure for a predetermined time (first high pressure maintaining step S120). The first high pressure maintaining step S120 can be performed under a first gas environment, and the first gas can be the same gas used in step S110.

[0048] Next, the pressure in the first chamber is reduced to a second high pressure (first pressure reduction step S130). The second high pressure is a pressure lower than the first high pressure and above atmospheric pressure. The first pressure reduction step S130 is the step of reducing the first high pressure to the second high pressure. This step does not require evacuating the first chamber and can be performed solely through valve actuation.

[0049] Then, it is confirmed whether the pressure increase / decrease process S110 to S130 is repeated (S140), and steps S110 to S130 are regarded as one cycle, which is repeated several times.

[0050] Then, the pressure in the first chamber is reduced so that the pressure in the first chamber reaches a first low pressure (a second pressure reducing step S150 ).

[0051] At this time, when the second high pressure is higher than the normal pressure, the second pressure reducing step S150 is divided into: a second-first pressure reducing step S160, reducing the pressure in the first chamber to make the pressure in the first chamber reach the normal pressure; a first normal pressure maintaining step S170, maintaining the pressure in the first chamber at the normal pressure for a predetermined time; and a second-second pressure reducing step S180, reducing the pressure in the first chamber to make the pressure in the first chamber reach the first low pressure (refer to Figure 2a Then, when the second high pressure is at normal pressure, the second pressure reducing step S150 is divided into: a first normal pressure maintaining step S170, maintaining the pressure in the first chamber at normal pressure for a predetermined time; a second pressure reducing step S180, reducing the pressure in the first chamber so that the pressure in the first chamber reaches the first low pressure (refer to Figure 2b ).

[0052] During the first atmospheric pressure maintaining step S170, a purge gas may be supplied into the first chamber. The purge gas may be an inert gas, such as nitrogen (N2). Supplying a purge gas into the first chamber during the first atmospheric pressure maintaining step S170 dilutes the first gas supplied during the first pressurization step S110 and the first high pressure maintaining step S120. This dilution improves overall process safety and facilitates discharge of the first gas during the second pressure reduction step S180.

[0053] The first low pressure is a pressure below atmospheric pressure, and can be approximately 10 to 0.01 Torr. The second-first pressure reduction step ( S160 ) is a step for reducing the pressure to atmospheric pressure. This step is performed solely through valve actuation, without evacuating the first chamber. The second-second pressure reduction step ( S180 ) is a step for reducing the pressure from atmospheric pressure to the first low pressure. This step can be performed by evacuating the first chamber.

[0054] Then, the pressure in the first chamber is maintained at the first low pressure for a predetermined time (first low pressure maintaining step S190). The predetermined time for maintaining the pressure in the first chamber at the first low pressure may vary depending on the type of film, the film forming method, etc., but the low pressure is maintained for more than one minute.

[0055] Conventional pressurization / depressurization processes repeatedly increase the pressure to a high pressure above atmospheric pressure and then decrease it to a low pressure below atmospheric pressure. This results in long process times and increases the thermal budget. In contrast, the pressurization / depressurization process of this embodiment repeatedly increases the pressure to a high pressure above atmospheric pressure and then decreases it to a high pressure below atmospheric pressure, thereby shortening the overall process time and reducing the thermal budget. Furthermore, the depressurization process can be performed without vacuuming.

[0056] Figures 3 to 5 This is a schematic diagram for explaining the execution of the pressure increasing step and the pressure decreasing step. Figures 3 to 5 This diagram models the state of the interior of the first chamber and the film after a titanium nitride (TiN) film is formed on a substrate by atomic layer deposition using a titanium tetrachloride (TiCl4) precursor and nitrogen (N2) or ammonia (NH3) reaction gas, and then a first pressurization step S110 and a first high-pressure maintaining step S120 are performed in a hydrogen (H2) environment and a first depressurization step S130 is performed.

[0057] Figure 3 This diagram schematically illustrates the state within a titanium nitride (TiN) thin film after it has been formed (as-dep.). The film contains chlorine (Cl), an impurity, after the film has been formed (as-dep.). The film can contain Cl loosely bonded to titanium (Ti), tightly bonded to titanium (Ti), or free, unbonded Cl.

[0058] Figure 4 This diagram schematically illustrates the state within the thin film after the first pressurization step S110 and the first high-pressure maintenance step S120 are performed in a hydrogen (H2) environment. When the first pressurization step S110 is performed in a hydrogen (H2) environment, chlorine (Cl) loosely bonded to titanium (Ti) and free, unbonded chlorine (Cl) combine with hydrogen (H) to form inert, easily vaporizable hydrogen chloride (HCl). This also increases the likelihood that chlorine (Cl) tightly bonded to titanium (Ti) will break this bond. Specifically, hydrogen (H2) gas reacts with impurities, namely chlorine (Cl), to form hydrogen chloride (HCl) as a byproduct.

[0059] Figure 5This is a schematic diagram of the execution process when the first pressure reduction step S130 is executed after the first pressure increase step S110 and the first high-pressure maintaining step S120 are executed in a hydrogen (H2) environment. If the first pressure reduction step S130 is executed, the pressure is rapidly reduced under the pressure increase state, thereby discharging chlorine (Cl) impurities to the outside of the film in the form of hydrogen chloride (HCl).

[0060] Steps S110 to S190 may be performed on a substrate that has not yet been thin-filmed. Specifically, steps S120 to S190 may be performed under a suitable gas atmosphere to treat the substrate before supplying the raw material gases for thin-film formation. This reduces surface imperfections on the substrate, thereby improving the physical properties of the thin film when the thin film is subsequently formed.

[0061] Furthermore, steps S110 to S190 can be performed on a substrate already having a thin film formed thereon to improve the physical properties of the already formed thin film. Alternatively, steps S110 to S190 can be performed while a thin film is being formed on the substrate. Specifically, steps S110 to S190 can be performed while film formation is stopped after supplying a raw material gas to the substrate to partially form the thin film. Subsequently, raw material gas can be supplied again to form the thin film. This process can be repeated to further improve the physical properties of the formed thin film.

[0062] The physical properties of the thin film change when the substrate processing method of this embodiment is performed. Figure 6 Shown.

[0063] Figure 6 This graph shows changes in sheet resistance before and after pressure increase / decrease treatment after a titanium nitride (TiN) thin film is formed on a substrate.

[0064] Figure 6 In Example 1, one cycle (S110-S130) of this embodiment is executed five times, and the thermal budget is 30 minutes. In Example 2, one cycle (S110-S130) is executed three times, and the thermal budget is 20 minutes. The case of Comparative Example 1 is a conventional pressurization / depressurization process (pressurization to a pressure above normal pressure and then depressurization to a pressure below normal pressure), with Figure 7 The pressure changes shown in Figure 7 One cycle is shown executed three times with a thermal budget of 30 minutes.

[0065] like Figure 6As shown, when comparing the cases where the same three cycles were performed (Example 2 and Comparative Example), Example 2 showed superior sheet resistance improvement (22.6% vs. 20.5%) and a 10-minute reduction in thermal budget. Furthermore, when comparing the cases with the same thermal budget (Example 1 and Comparative Example), Example 1 showed significantly superior sheet resistance improvement (23.7% vs. 20.5%). This demonstrates that, compared to conventional boost / depressurization processes, the boost / depressurization process of this embodiment achieves superior sheet resistance improvement while also shortening the thermal budget.

[0066] Figure 8 FIG. 1 is a flowchart illustrating an execution process of another embodiment of a substrate processing method according to the present invention.

[0067] Reference Figure 8 , another embodiment of the substrate processing method of the present invention is that the substrate is first transported into the first chamber (S210). A thin film may be formed on the substrate, and the thin film formed on the substrate may be a thin film that constitutes at least a part of the gate insulating film of the transistor. In addition, the thin film formed on the substrate may contain at least one of metal elements, group IV elements, III-V compounds, II-VI compounds, nitrogen (N), oxygen (O), and boron (B). For example, it may be a thin film composed of silicon, silicon oxide, silicon nitride, metal oxide, metal nitride, III-V compounds, II-VI compounds, ternary compounds, and quaternary compounds. Step S210 is the same as in Figure 1 The step S100 shown and described is the same, so detailed description is omitted.

[0068] Then, perform the Figure 1 In particular, the steps S110 to S190 (S220) are performed under the first gas environment. Figure 1 Step S110 and step S120. Step S220 is the same as Figure 1 The same as shown and described in , so detailed description is omitted.

[0069] Then, the process is performed under a second gas environment different from the first gas environment. Figure 1 In particular, the steps S110 to S190 (S230) are performed under the second gas environment. Figure 1 The second gas may be a gas containing at least one of hydrogen (H), oxygen (O), nitrogen (N), chlorine (Cl), and fluorine (F). For example, a gas containing nitrogen (N) may be supplied for nitridation. The nitrogen (N)-containing gas may be ammonia, methylamine, dimethylamine, or the like.

[0070] In the case of step S230, in order to distinguish it from step S220, step S110 of step S230 can be represented by a second pressurizing step of increasing the pressure in the first chamber to reach a third high pressure; step S120 of step S230 can be represented by a second high pressure maintaining step of maintaining the third high pressure for a predetermined time; step S130 of step S230 can be represented by a third pressure reducing step of reducing the pressure in the first chamber to make the pressure in the first chamber reach a fourth high pressure lower than the third high pressure and above normal pressure; step S160 of step S230 can be represented by reducing the pressure to make the first chamber The fourth depressurization step of step S230 can be represented by the fourth depressurization step of reducing the pressure in the first chamber to reach normal pressure; step S170 of step S230 can be represented by the second normal pressure maintaining step of maintaining normal pressure for a predetermined time; step S180 of step S230 can be represented by the fourth depressurization step of reducing the pressure in the first chamber so that the pressure in the first chamber reaches a second low pressure; step S150 of step S230 can be represented by the fourth depressurization step of reducing the pressure in the first chamber to reach a second low pressure lower than normal pressure; step S190 of step S230 can be represented by the second low pressure maintaining step of maintaining the second low pressure for a predetermined time. In this way, different expressions can be used to distinguish step S230 from step S220, but the process of changing and maintaining the pressure in the first chamber is the same as in step S230. Figure 1 Same as shown and described.

[0071] Then, the first high pressure and the third high pressure may be the same or different, and the time for maintaining the first high pressure and the second high pressure may be the same or different. The second high pressure and the fourth high pressure may be the same or different. In addition, the time for maintaining normal pressure in step S220 and step S230 may be the same or different. Then, the first low pressure and the second low pressure may be the same or different, and the time for maintaining the first low pressure and the second low pressure may be the same or different. Then, in the case of the step of maintaining normal pressure for a predetermined time in step S230, a purge gas may be supplied into the first chamber, and the purge gas may utilize an inert gas, i.e., nitrogen (N2) gas. In this way, if a purge gas is supplied when normal pressure is maintained for a predetermined time, the second gas supplied in the pressurization step, which is diluted as described above, may be exhausted.

[0072] The optimal gas for the first gas and the second gas can be selected based on the thin film to be formed on the substrate. For example, the thin film formed on the substrate can be a nitride thin film or a metal nitride thin film. More specifically, it can be a titanium nitride (TiN) thin film. In order to form the metal nitride thin film, chemical vapor deposition or atomic layer deposition can be used. In this case, a halogen-containing metal precursor can be used as the metal precursor, and a nitrogen-containing gas can be used as the reaction gas. More specifically, a titanium nitride (TiN) thin film can be formed by atomic layer deposition using a titanium tetrachloride (TiCl4) precursor and nitrogen (N2) or ammonia (NH3) reaction gas.

[0073] As described above, when forming a nitride thin film on a substrate, the first gas can be a reducing gas, such as a hydrogen (H)-containing gas. More specifically, hydrogen (H2) gas can be used. The second gas can be a nitrogen (N)-containing gas, more specifically, ammonia (NH3) gas.

[0074] At this time, the number of times steps S110 to S130 are repeated in step S220 is greater than the number of times steps S110 to S130 are repeated in step S230.

[0075] Figure 9 This is a schematic diagram for explaining the case where a pressure increasing step and a pressure decreasing step are performed under a first gas environment and then a pressure increasing step and a pressure decreasing step are performed under a second gas environment. Figure 9 This is a diagram that models the state inside the film after a titanium nitride (TiN) film is formed on a substrate by an atomic layer deposition method using a titanium tetrachloride (TiCl4) precursor and nitrogen (N2) or ammonia (NH3) reaction gas, and after a pressurization step and a depressurization step are performed in a hydrogen (H2) environment and a pressurization step and a depressurization step are performed in an ammonia (NH3) gas environment.

[0076] Reference Figure 9 If the titanium nitride (TiN) film is subjected to a pressurization step and a pressure reduction step in a hydrogen (H2) gas environment, and then a pressurization step and a pressure reduction step are performed in an ammonia (NH3) gas environment, nitrogen (N) is bonded at the location where the chlorine (Cl) impurity is removed, and the overall bonding state is also more solid. Based on this, after the titanium nitride (TiN) film is formed (as-dep.), a titanium nitride (TiN) film with a high titanium (Ti) content is formed. However, if steps S220 and S230 are performed, the impurities are removed, and the composition ratio of titanium (Ti) and nitrogen (N) becomes a titanium nitride (TiN) film with a composition ratio of almost 1:1.

[0077] Specifically, after forming the titanium nitride (TiN) film (as-dep.), a titanium nitride (TiN) film with a high titanium (Ti) content and a high chlorine (Cl) impurity content is formed. However, if step S220 is performed in a hydrogen (H2) environment, the pressurization step breaks the bond between the titanium (Ti) and the chlorine (Cl) impurities to form easily vaporized hydrogen chloride (HCl). The depressurization step then diffuses the hydrogen chloride (HCl) to the outside, further reducing impurities and improving electrical characteristics. At this time, as in the present embodiment, maintaining the reduced pressure for a predetermined time during the depressurization step improves the removal of chlorine (Cl) impurities.

[0078] Then, if step S230 is performed under an ammonia (NH3) environment, nitrogen (N) bonds to the locations where chlorine (Cl) impurities were removed by the pressurization step, increasing the bonding between titanium (Ti) and nitrogen (N). Furthermore, the residual impurities are further reduced by the pressure reduction step, thereby improving oxidation resistance. In the case of this embodiment, the chlorine (Cl) impurity removal effect is enhanced by maintaining the low pressure for a predetermined time in step S220 under a hydrogen (H2) environment. Therefore, step S230 under an ammonia (NH3) environment further increases the bonding between titanium (Ti) and nitrogen (N), resulting in a titanium nitride (TiN) film with a composition ratio of titanium (Ti) to nitrogen (N) closer to 1:1, thereby further improving oxidation resistance.

[0079] In addition, in the case of previous plasma nitridation processes, good nitridation could not be achieved on the side walls or bottom of 3D semiconductor devices or semiconductor elements with high aspect ratios. However, in contrast, in the case of this embodiment, the substrate can be uniformly processed in 3D semiconductor devices or semiconductor elements with high aspect ratios without using plasma, so there is no risk of plasma damage.

[0080] exist Figure 8 A method for performing pressure increase / depressurization processing in different gas environments using a single chamber is shown and described. This substrate processing method can be performed using a batch substrate processing apparatus capable of simultaneously processing multiple substrates. Furthermore, other substrate processing apparatuses can also perform pressure increase / depressurization processing in different gas environments using a single chamber.

[0081] Then, the present invention includes the case where pressure increase / depressurization processes performed under mutually different gas environments are performed using mutually different chambers.

[0082] Figure 10 This is a flowchart illustrating the execution process of another embodiment of the substrate processing method of the present invention. This embodiment illustrates an embodiment in which a pressure increase / depressurization process is performed in a first chamber under a first gas environment, and in a second chamber under a second gas environment. Accordingly, this embodiment can be performed using a substrate processing apparatus having multiple chambers or using different substrate processing apparatuses. For example, the method can be performed using a clustered substrate processing apparatus having multiple chambers.

[0083] Reference Figure 10, another embodiment of the substrate processing method of the present invention is that the substrate is first transported into the first chamber (S310). The first chamber can be a process chamber of a cluster-type single-wafer substrate processing device. A thin film can be formed on the substrate, and the thin film formed on the substrate can be a thin film that constitutes at least a part of the gate insulating film of the transistor. In addition, the thin film formed on the substrate may contain at least one of metal elements, group IV elements, III-V compounds, II-VI compounds, nitrogen (N), oxygen (O), and boron (B). For example, it can be a thin film composed of silicon, silicon oxide, silicon nitride, metal oxide, metal nitride, III-V compounds, II-VI compounds, ternary compounds, and quaternary compounds. Step S310 is the same as in Figure 1 The step S100 shown and described is similar, so detailed description is omitted.

[0084] Then, the first chamber is subjected to the first gas environment. Figure 1 Step S110 to step S190 (S320) are performed. Step S320 is the same as step S220, so detailed description is omitted.

[0085] Then, the substrate is unloaded from the first chamber (S330). Then, the substrate is transported into the second chamber (S340). If the substrate processing apparatus used in this embodiment is a multi-substrate processing apparatus having one chamber, after one substrate processing apparatus performs step S320, the substrate is unloaded from the chamber of that substrate processing apparatus (S330) and transported into the chamber of another substrate processing apparatus (S340). Then, if the substrate processing apparatus used in this embodiment is a clustered single-wafer substrate processing apparatus having multiple chambers, after the first chamber performs step S320, the substrate is unloaded from the first chamber using a substrate transport module (S330) and transported into the second chamber (S340).

[0086] Then, the process is performed in a second chamber under a second gas environment different from the first gas environment. Figure 1 Steps S110 to S190 (S350) are performed in the second chamber instead of the first chamber. Step S350 is the same as step S230, so detailed description is omitted.

[0087] For the first gas and the second gas, the optimal gas can be selected according to the thin film to be formed on the substrate. For example, the thin film formed on the substrate can be a nitride thin film or a metal nitride thin film. More specifically, it can be a titanium nitride (TiN) thin film. To form the metal nitride thin film, chemical vapor deposition or atomic layer deposition can be used. In this case, a halogen-containing metal precursor can be used as the metal precursor, and a nitrogen-containing gas can be used as the reaction gas. More specifically, a titanium nitride (TiN) thin film can be formed by atomic layer deposition using a titanium tetrachloride (TiCl4) precursor and nitrogen (N2) or ammonia (NH3) reaction gas.

[0088] As described above, when forming a nitride thin film on a substrate, the first gas used in the first chamber can be a reducing gas, such as a hydrogen (H)-containing gas. More specifically, hydrogen (H2) gas can be used. The second gas used in the second chamber can be a nitrogen (N)-containing gas, more specifically, ammonia (NH3) gas.

[0089] At this time, the number of times steps S110 to S130 are repeated in step S320 is greater than the number of times steps S110 to S130 are repeated in step S350.

[0090] As described above, the present invention can perform pressurization / depressurization treatments in different chambers under different gas environments. In this case, impurities can also be effectively removed as described above, thereby improving electrical properties. In the case of desalting the film, pressurization / depressurization treatments are performed under hydrogen (H2) gas and ammonia (NH3) gas environments, thereby increasing the nitrogen (N) content in the film, thereby improving oxidation resistance.

[0091] The embodiments of the present invention are shown and described above, but the present invention is not limited to the specific embodiments described above. Rather, any person having ordinary knowledge in the technical field to which the present invention belongs can certainly make various modified implementations without departing from the main points of the present invention as claimed in the claims, and such changes are within the scope of the claims.

Claims

1. A substrate processing method, characterized in that: include: The step of moving the substrate into the first chamber; a first pressurizing step of increasing the pressure in the first chamber so that the pressure in the first chamber reaches a first high pressure higher than normal pressure; a first pressure reduction step of reducing the pressure in the first chamber so that the pressure in the first chamber reaches a second high pressure that is lower than the first high pressure and above normal pressure; a first pressure-increasing and pressure-decreasing repeatedly performing step, wherein the first pressure-increasing step and the first pressure-decreasing step are repeatedly performed a predetermined number of times; and The second pressure reduction step reduces the pressure in the first chamber so that the pressure in the first chamber reaches a first low pressure lower than normal pressure.

2. The substrate processing method according to claim 1, wherein: When the second high pressure is greater than normal pressure, the second pressure reducing step includes: A second step of reducing the pressure in the first chamber to reduce the pressure in the first chamber to a normal pressure; and a second depressurization step of reducing the pressure in the first chamber so that the pressure in the first chamber reaches the first low pressure; When the second high pressure is normal pressure, the second pressure reducing step includes: The second depressurization step is to reduce the pressure in the first chamber so that the pressure in the first chamber reaches the first low pressure.

3. The substrate processing method according to claim 2, wherein: The second step of reducing pressure is: The second-second depressurization step includes a first normal pressure maintaining step of maintaining normal pressure for a predetermined time.

4. The substrate processing method according to claim 3, wherein: The first normal pressure maintaining step supplies a purge gas.

5. The substrate processing method according to claim 1, wherein: The second pressure reducing step includes a first low pressure maintaining step of maintaining the first low pressure for a predetermined time.

6. The substrate processing method according to claim 1, wherein: A first high-pressure maintaining step of maintaining the first high pressure for a predetermined time is included between the first pressure increasing step and the first pressure decreasing step; The first pressure increase and reduction repeated execution step repeatedly executes the first pressure increase step, the first high pressure maintaining step and the first pressure reduction step in sequence for several times.

7. The substrate processing method according to claim 1, wherein: The first pressurizing step is performed under a first gas environment, After the second depressurization step, the method comprises: a second pressurizing step of increasing the pressure in the first chamber under a second gas environment different from the first gas environment, so that the pressure in the first chamber reaches a third high pressure higher than normal pressure; a third pressure reduction step of reducing the pressure in the first chamber so that the pressure in the first chamber reaches a fourth high pressure that is lower than the third high pressure and above normal pressure; a second pressure-increasing and pressure-decreasing repeatedly performing step of repeatedly performing the second pressure-increasing step and the third pressure-decreasing step a predetermined number of times; and The fourth pressure reduction step is to reduce the pressure in the first chamber so that the pressure in the first chamber reaches a second low pressure lower than normal pressure.

8. The substrate processing method according to claim 1, wherein: The first pressurizing step is performed under a first gas environment, After the second depressurization step, the method comprises: a step of carrying the substrate out of the first chamber; The step of moving the substrate into a second chamber; a second pressurizing step of increasing the pressure in the second chamber under a second gas environment different from the first gas environment, so that the pressure in the second chamber reaches a third high pressure higher than normal pressure; a third pressure reducing step of reducing the pressure in the second chamber so that the pressure in the second chamber reaches a fourth high pressure that is lower than the third high pressure and above normal pressure; a second pressure-increasing and pressure-decreasing repeatedly performing step of repeatedly performing the second pressure-increasing step and the third pressure-decreasing step a predetermined number of times; and The fourth pressure reduction step reduces the pressure in the second chamber so that the pressure in the second chamber reaches a second low pressure lower than normal pressure.

9. The substrate processing method according to claim 7 or 8, characterized in that: The fourth pressure reducing step is followed by a second low pressure maintaining step of maintaining the second low pressure for a predetermined time.

10. The substrate processing method according to claim 7, wherein: When the fourth high pressure is higher than normal pressure, the fourth pressure reducing step includes: Fourthly, a depressurization step of reducing the pressure in the first chamber so that the pressure in the first chamber reaches normal pressure; and a fourth-second depressurization step of reducing the pressure in the first chamber so that the pressure in the first chamber reaches the second low pressure; When the fourth high pressure is normal pressure, the fourth pressure reducing step includes: The fourth-second depressurization step reduces the pressure in the first chamber so that the pressure in the first chamber reaches the second low pressure.

11. The substrate processing method according to claim 8, wherein: When the fourth high pressure is higher than normal pressure, the fourth pressure reducing step includes: A fourth step of reducing the pressure in the second chamber to reduce the pressure in the second chamber to a normal pressure; and a fourth-second depressurization step of reducing the pressure in the second chamber so that the pressure in the second chamber reaches the second low pressure; When the fourth high pressure is normal pressure, the fourth pressure reducing step includes: The fourth-second depressurization step reduces the pressure in the second chamber so that the pressure in the second chamber reaches the second low pressure.

12. The substrate processing method according to claim 10 or 11, characterized in that: The fourth depressurization step is a second constant pressure maintaining step including maintaining the normal pressure for a predetermined time before the fourth-second depressurization step.

13. The substrate processing method according to claim 12, wherein: The second normal pressure maintaining step supplies a purge gas.

14. The substrate processing method according to claim 7 or 8, characterized in that: A second high-pressure maintaining step of maintaining the third high pressure for a predetermined time is included between the second pressure increasing step and the third pressure decreasing step; The second pressure increase and reduction repeated execution step is to repeatedly execute the second pressure increase step, the second high pressure maintaining step and the third pressure reduction step in sequence for a predetermined number of times.

15. The substrate processing method according to claim 7 or 8, characterized in that: The first gas is a gas containing at least one of hydrogen, oxygen, nitrogen, chlorine, and fluorine.

16. The substrate processing method according to claim 7 or 8, characterized in that: The second gas is a gas containing at least one of hydrogen, oxygen, nitrogen, chlorine, and fluorine.

17. The substrate processing method according to any one of claims 1 to 8, wherein: A thin film is formed on the substrate.

18. The substrate processing method according to claim 17, wherein: The thin film constitutes at least a portion of a gate insulating film of a transistor.

19. The substrate processing method according to claim 17, wherein: The film contains at least one of metal elements, group IV elements, III-V compounds, II-VI compounds, nitrogen, oxygen, and boron.

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