Method for cleaning chamber

Abstract

A method for cleaning a chamber in which a film containing ruthenium has been deposited, according to one embodiment of the present invention, comprises the steps of: a) injecting an oxygen-containing gas into the chamber; and b) injecting a hydrogen-containing gas into the chamber.

Description

Chamber cleaning method

[0001] The present invention relates to a chamber cleaning method, and more specifically, to an in-situ cleaning method for a ruthenium (Ru) deposition chamber.

[0002] A capacitor comprises a substrate, a diffusion barrier layer formed on the substrate, a lower electrode formed on the diffusion barrier layer, a dielectric film formed on the lower electrode, and an upper electrode formed on the dielectric film. The lower electrode may be formed of a ruthenium metal film, and the diffusion barrier layer may be formed of a ruthenium oxide film. Here, the diffusion barrier layer is a film formed to inhibit or prevent ruthenium (Ru) contained in the lower electrode from migrating or diffusing into the substrate.

[0003] In forming a ruthenium oxide film, a ruthenium metal film is formed on a substrate by spraying a precursor containing ruthenium (Ru), and oxygen gas is sprayed toward the ruthenium metal film.

[0004] After forming a ruthenium (Ru) film or a ruthenium oxide film, the Ru chamber requires a cleaning process for process stability.

[0005] When cleaning the inside of a reaction vessel after forming a ruthenium film or a ruthenium oxide film, a technology is required that can efficiently clean the reaction vessel without damaging it.

[0006] Typically, when performing plasma cleaning using chlorine-containing gases, applying the in-situ cleaning method at the deposition temperature results in redeposition; therefore, the in-situ cleaning method is not applied at the deposition temperature but is instead applied after the temperature has dropped following the completion of the process. Consequently, process time is inevitably delayed to the extent that it is practically difficult to regard this as in-situ cleaning. Furthermore, since equipment employing molding heaters requires a significant amount of time for temperature rise and fall, this issue becomes a more significant problem in such equipment.

[0007] Furthermore, when using conventional in-situ cleaning methods that utilize Cl2 and O2 gas plasmas, aluminum (Al) is easily etched by the Cl2 plasma, making it impossible to use low-cost Al components within the chamber. To address this, the surfaces of these components must be protected by methods such as anodizing or by fabricating covers made of materials like graphite. However, using such measures not only increases the manufacturing cost of the equipment but also reduces adhesion between the components and the ruthenium film, which shortens the chamber cleaning cycle.

[0008] The technical problem to be solved by the present invention is a method for in situ cleaning of Ru attached to the chamber wall in a high-temperature chamber.

[0009] A cleaning method for a chamber having a ruthenium-containing film deposited thereon according to one embodiment of the present invention comprises: a) a step of injecting an oxygen-containing gas into the chamber; and b) a step of injecting a hydrogen-containing gas into the chamber.

[0010] In one embodiment of the present invention, the cycle of steps a) and b) can be repeated.

[0011] In one embodiment of the present invention, the oxygen-containing gas may include one or more of oxygen (O2) gas, ozone (O3) gas, nitrous oxide (N2O) gas, nitric oxide (NO), oxygen (O2) plasma, nitrous oxide (N2O) plasma, nitric oxide (NO) plasma and ozone (O3) plasma.

[0012] In one embodiment of the present invention, the hydrogen-containing gas may include one or more of hydrogen (H2) gas and hydrogen (H2) plasma.

[0013] In one embodiment of the present invention, the cleaning temperature in the chamber may be 100 degrees Celsius to 400 degrees Celsius.

[0014] In one embodiment of the present invention, the step of injecting an oxygen-containing gas into the chamber may include a step of vaporizing ruthenium (Ru) into ruthenium tetroxide (RuO4) using the oxygen-containing gas, wherein a film formed on the inner wall or part of the chamber contains ruthenium (Ru).

[0015] In one embodiment of the present invention, the step of injecting a hydrogen-containing gas into the chamber may include a step of reducing ruthenium dioxide (RuO2), which is not converted into ruthenium tetroxide (RuO4) by the oxygen-containing gas, to ruthenium (Ru) using the hydrogen-containing gas.

[0016] A cleaning method for a chamber having a ruthenium-containing film deposited thereon according to one embodiment of the present invention comprises: a) a step of injecting an oxygen-containing gas into the chamber; and b) a step of injecting a chlorine-containing gas into the chamber.

[0017] In one embodiment of the present invention, the cycle of steps a) and b) can be repeated.

[0018] In one embodiment of the present invention, the oxygen-containing gas may include one or more of oxygen (O2) gas, ozone (O3) gas, nitrous oxide (N2O) gas, nitric oxide (NO), oxygen (O2) plasma, nitrous oxide (N2O) plasma, nitric oxide (NO) plasma and ozone (O3) plasma.

[0019] In one embodiment of the present invention, the chlorine-containing gas may include one or more of chlorine (Cl2) gas and chlorine (Cl2) plasma.

[0020] In one embodiment of the present invention, the cleaning temperature in the chamber may be 100 degrees Celsius to 400 degrees Celsius.

[0021] In one embodiment of the present invention, the step of injecting an oxygen-containing gas into the chamber may include a step of vaporizing ruthenium (Ru) into ruthenium tetroxide (RuO4) using the oxygen-containing gas, wherein a film formed on the inner wall or part of the chamber contains ruthenium (Ru).

[0022] In one embodiment of the present invention, the step of injecting a chlorine-containing gas into the chamber may include a step of replacing ruthenium dioxide (RuO2) that is not converted into ruthenium tetroxide (RuO4) by the oxygen-containing gas with ruthenium chloride (RuClx) or ruthenium chloride oxide (RuClOx) using the chlorine-containing gas.

[0023] A cleaning method for a ruthenium (Ru) deposition chamber according to one embodiment of the present invention comprises: a step of vaporizing ruthenium (Ru) deposited on the inner wall of a chamber in which a ruthenium (Ru) deposition process is performed into ruthenium tetroxide (RuO4) using an oxygen-containing gas; a step of reducing ruthenium dioxide (RuO2) that is not converted into ruthenium tetroxide (RuO4) by the oxygen-containing gas into ruthenium (Ru) using a hydrogen-containing gas; and a step of vaporizing the reduced ruthenium (Ru) into ruthenium tetroxide (RuO4) using an oxygen-containing gas.

[0024] In one embodiment of the present invention, the oxygen-containing gas may include at least one of oxygen (O2) gas, ozone (O3) gas, oxygen (O2) plasma, and ozone (O3) plasma.

[0025] In one embodiment of the present invention, the hydrogen-containing gas may be at least one of hydrogen (H2) gas and hydrogen (H2) plasma.

[0026] In one embodiment of the present invention, the inner wall temperature of the chamber may be the same as the ruthenium (Ru) deposition process and may be 300 to 400 degrees Celsius.

[0027] In one embodiment of the present invention, the heating of the chamber is achieved by an infrared lamp positioned outside the chamber, and the chamber may include an area through which the infrared rays are transmitted.

[0028] A cleaning method for a ruthenium (Ru) deposition chamber according to one embodiment of the present invention comprises: a step of vaporizing ruthenium (Ru) deposited on the inner wall of a chamber in which a ruthenium (Ru) deposition process is performed into ruthenium tetroxide (RuO4) using an oxygen-containing gas; and a step of converting ruthenium dioxide (RuO2) that is not converted into ruthenium tetroxide (RuO4) by the oxygen-containing gas into ruthenium chloride (RuClx) or ruthenium chloride oxide (RuClOx) using a chlorine-containing gas.

[0029] In one embodiment of the present invention, the oxygen-containing gas may include at least one of oxygen (O2) gas, ozone (O3) gas, oxygen (O2) plasma, and ozone (O3) plasma.

[0030] A method for cleaning a ruthenium (Ru) deposition chamber, characterized in that, in one embodiment of the present invention, the chlorine-containing gas comprises at least one of chlorine (Cl2) gas, chlorine and oxygen-containing gas, chlorine (Cl2) plasma, and chlorine and oxygen-containing gas plasma.

[0031] In one embodiment of the present invention, the inner wall temperature of the chamber may be the same as the ruthenium (Ru) deposition process and may be 300 to 400 degrees Celsius.

[0032] In one embodiment of the present invention, the heating of the chamber is achieved by an infrared lamp positioned outside the chamber, and the chamber may include an area through which the infrared rays are transmitted.

[0033] The ruthenium (Ru) deposition chamber cleaning method of the present invention can prevent the attachment of foreign substances and contamination on a substrate caused by ruthenium (Ru) attached to the chamber wall by removing ruthenium (Ru) attached to the chamber wall through repeated oxidation and reduction processes.

[0034] The ruthenium (Ru) deposition chamber cleaning method of the present invention can prevent the attachment of foreign substances and contamination on a substrate caused by ruthenium (Ru) attached to the chamber wall by removing ruthenium (Ru) attached to the chamber wall through repeated oxidation and chlorine substitution processes.

[0035] FIGS. 1 to 4 are flowcharts illustrating a ruthenium (Ru) deposition chamber cleaning method according to embodiments of the present invention.

[0036] When a cleaning process is performed on the chamber walls using ruthenium (Ru) (solid) as ruthenium tetroxide (RuO4) (gas) via ozone (O3) or O3 plasma, it becomes difficult for Ru(s) to transform into RuO4(g) from the moment the surface of the Ru on the chamber walls becomes ruthenium dioxide (RuO2). Therefore, a technology is required to increase real-time (in-situ) cleaning efficiency by inducing a reduction or substitution reaction with Ru or RuCl in the parts transformed into ruthenium dioxide (RuO2). Specifically, to clean Ru deposited on the chamber walls and parts, Ru(s) is first removed as RuO4(g) through an oxidation process. Subsequently, the remaining RuO2 (solid) is removed through two pathways (reduction of RuO2 with H2 or substitution of RuO2 with chlorine gas). The part may include at least one of a susceptor, a gas injection unit, a plasma electrode, and a sidewall liner. The part may be a component on which contaminants (Ru) are deposited, excluding the chamber walls and the substrate.

[0037] When chamber cleaning is performed using O3 gas or O3 plasma in a vacuum high-temperature chamber (300 to 400 degrees Celsius) in which Ru (solid) and precious metals (Cu, Pd, Ag, Pt, Au, Rh, Re, Os, Ir) are deposited, the Ru (solid) deposited on the inner wall of the chamber is oxidized to RuO4 (gas) and vaporized into a gaseous form.

[0038] At high chamber temperatures of 300 to 400 degrees Celsius, some of the Ru (solid) on the chamber wall is converted into RuO4 (gas) using oxygen (O2) gas, ozone (O3) gas, oxygen (O2) plasma, or O3 plasma. However, from the moment the surface of Ru (solid) is combined (converted) into RuO2 (solid), the rate at which the Ru (solid) on the chamber wall becomes RuO4 (gas) decreases significantly.

[0039] For example, when depositing Ru on a substrate, the deposition temperature of the susceptor may be 300 degrees Celsius and the temperature of the chamber wall may be 100 degrees Celsius. In this case, during the process of depositing Ru on the substrate, Ru is mainly deposited on the substrate, and Ru may be slightly deposited on the chamber wall due to the low temperature.

[0040] Meanwhile, when performing a cleaning process to remove Ru deposited on the chamber wall, the Ru deposited on the chamber wall forms RuO2 (solid) due to oxygen-containing gas; however, the Ru may not completely vaporize into RuO4 (gas). Similarly, Ru deposited on the sidewalls (or parts) of the susceptor forms RuO2 (solid) due to oxygen-containing gas and may not completely vaporize into RuO4 (gas). Therefore, the cleaning process to remove Ru deposited on the chamber wall and the sidewalls of the susceptor is difficult. To remove the Ru formed on the chamber wall and the Ru deposited on the sidewalls (or parts) of the susceptor, a cleaning process using chlorine gas and plasma may be used. However, chlorine gas can damage the metal chamber wall and cause Ru to re-deposit on the susceptor sidewalls (or parts), etc.

[0041] For example, when depositing Ru on a substrate, the deposition temperature of the susceptor may be 300 degrees, and the temperature of the chamber wall may also be 300 degrees. In the process of depositing Ru on the substrate, Ru can be well deposited on both the substrate and the chamber wall. Meanwhile, if a cleaning process using O3 gas is performed to remove the Ru deposited on the chamber wall, RuO2 (solid) may be formed and not completely vaporized into RuO4 (gas). Ru deposited on the sidewall of the susceptor may form RuO2 (solid) by an oxygen-containing gas and not completely vaporize into RuO4 (gas). Additionally, due to the chamber wall temperature of 300 degrees, the step of reducing lucerium dioxide (RuO2) to Ru (solid) using a hydrogen-containing gas can be easily performed. By repeating such oxidation to RuO4 (gas) and reduction to Ru (solid), the Ru deposited on the chamber wall and the sidewall (or part) of the susceptor can be removed. When the temperature of the susceptor (or part) and the chamber wall are high, in the Ru deposition process, a large amount of Ru can be deposited on the sidewalls (or parts) of the susceptor and the chamber wall due to the high temperature. This Ru deposited on the chamber wall can be reliably cleaned by a repetitive chamber cleaning process.

[0042] For in-situ chamber cleaning, if the temperature of the chamber wall and / or susceptor (or part) is lowered to below 200 degrees Celsius, a problem may arise where the mass production of Ru deposition on the substrate is significantly reduced.

[0043] Accordingly, the present invention relates to a Ru cycle chamber cleaning method that allows the chamber wall temperature and the susceptor (or part) temperature to be used at a Ru deposition temperature (300°C to 400°C). That is, the Ru cycle cleaning method comprises the steps of: converting Ru (solid) into lucerium tetroxide (RuO4) using an oxygen-containing gas and vaporizing it; and reducing lucerium dioxide (RuO2) to form Ru (solid). Again, it includes the step of converting Ru (solid) into lucerium tetroxide (RuO4) using an oxygen-containing gas and vaporizing it. By repeating this process, Ru (solid) attached to the chamber wall at a high temperature of 300°C to 400°C can be removed.

[0044] If a metal chamber is used, the temperature of the chamber wall can be heated to a level of 300 to 400 degrees Celsius by a heating heater. If the chamber is made of a transparent material such as quartz, the walls of the chamber can be heated to a level of 300 to 400 degrees Celsius by an infrared heater.

[0045] A method for cleaning a Ru deposition chamber may be a real-time cleaning method in which the Ru deposition chamber is periodically cleaned after multiple Ru depositions are performed. Alternatively, a real-time cleaning method in which the Ru deposition chamber is cleaned immediately after one Ru deposition is performed is also possible. The present invention relates to a real-time cleaning method, wherein the Ru deposition chamber may be a single-wafer type chamber or a batch processing chamber that processes multiple substrates simultaneously.

[0046] Oxygen-containing gas or hydrogen-containing gas can be activated by plasma, ultraviolet light, infrared light, or temperature (heat). The temperature of the chamber for activation can be 300 to 400 degrees Celsius. The plasma for activation can reduce the temperature of the chamber and the temperature of the parts for oxidation, reduction, or substitution reactions.

[0047] When plasma is used, the plasma generation method may be inductively coupled plasma, capacitively coupled plasma, or microwave plasma. When plasma is used, the methods include generating plasma directly within the deposition chamber and using remote plasma in the deposition chamber. When remote plasma is used, an active species formed in the plasma may be provided to the deposition chamber.

[0048] Immediately after the oxidation / reduction / substitution process, the process may further include an inert gas purge step and / or a base pumping step for removing oxygen / hydrogen / RuClx attached to the surface of the chamber wall. The inert gas purge step may remove oxygen / hydrogen / RuClx attached to the surface of the chamber wall by injecting an inert gas (Ar, He, N2) into the chamber. The base pumping step may reduce pressure and remove attached oxygen / hydrogen / RuClx attached to the surface of the chamber wall by performing exhaust pumping while the injection of external gas is stopped.

[0049] Hereinafter, preferred embodiments of the present invention will be described in detail with reference to the attached drawings. However, the present invention is not limited to the embodiments described herein and may be embodied in other forms. Rather, the embodiments introduced herein are provided to ensure that the disclosed content is thorough and complete and to ensure that the spirit of the present invention is sufficiently conveyed to those skilled in the art. In the drawings, components are exaggerated for clarity. Throughout the specification, parts indicated by the same reference numeral represent the same components.

[0050] FIG. 1 is a flowchart illustrating a ruthenium (Ru) deposition chamber cleaning method according to one embodiment of the present invention.

[0051] Referring to FIG. 1, a cleaning method for a chamber on which a ruthenium-containing film has been deposited comprises: a) a step of injecting an oxygen-containing gas into the chamber (S20); and b) a step of injecting a hydrogen-containing gas into the chamber (S30). The cleaning method may repeat the cycle of steps a) and b) (S40).

[0052] The injection of an oxygen-containing gas can be performed by a gas injection unit or an electrode for generating plasma, etc. In the case of a single-wafer device, a dummy substrate may be placed on the susceptor to prevent damage and contamination of the susceptor. The pressure of the chamber may be maintained at a predetermined pressure by the operation of a vacuum pump. To activate the oxygen-containing gas, the chamber wall may be heated to 100 to 400 degrees Celsius (S10). Plasma may be formed to activate the oxygen-containing gas. The plasma may generate the oxygen-containing gas inside the chamber or form plasma outside the chamber to inject active species into the chamber. To activate the oxygen-containing gas, ultraviolet or infrared rays may be irradiated into the chamber.

[0053] The oxygen-containing gas may include one or more of oxygen (O2) gas, ozone (O3) gas, nitrous oxide (N2O) gas, nitric oxide (NO), oxygen (O2) plasma, nitrous oxide (N2O) plasma, nitric oxide (NO) plasma, and ozone (O3) plasma. The hydrogen-containing gas may include one or more of hydrogen (H2) gas and hydrogen (H2) plasma.

[0054] The cleaning temperature inside the chamber may be 100 degrees Celsius to 400 degrees Celsius (S10).

[0055] The method may include a step of injecting an oxygen-containing gas into the chamber, wherein a film formed on the inner wall or part of the chamber contains ruthenium (Ru), and a step of vaporizing the ruthenium (Ru) into ruthenium tetroxide (RuO4) using the oxygen-containing gas.

[0056] The step of injecting a hydrogen-containing gas into the chamber may include a step of reducing ruthenium dioxide (RuO2), which is not converted into ruthenium tetroxide (RuO4) by the oxygen-containing gas, to ruthenium (Ru) using the hydrogen-containing gas.

[0057] Immediately after the oxidation / reduction process, an inert gas purge step and / or a base pumping step may be further included to remove oxygen / hydrogen attached to the surface of the chamber wall. The inert gas purge step may remove oxygen / hydrogen attached to the surface of the chamber wall by injecting an inert gas (Ar, He, N2) into the chamber. The base pumping step may reduce pressure and remove attached oxygen / hydrogen attached to the surface of the chamber wall by performing exhaust pumping while stopping the injection of external gas.

[0058] FIG. 2 is a flowchart illustrating a ruthenium (Ru) deposition chamber cleaning method according to one embodiment of the present invention.

[0059] Referring to FIG. 2, a cleaning method for a chamber on which a ruthenium-containing film has been deposited comprises: a) a step of injecting an oxygen-containing gas into the chamber (S20); and b) a step of injecting a chlorine-containing gas into the chamber (S30a). The cycle of steps a) and b) is repeated (S40). The cleaning temperature within the chamber may be 100 degrees Celsius to 400 degrees Celsius (S10).

[0060] The oxygen-containing gas may include one or more of oxygen (O2) gas, ozone (O3) gas, nitrous oxide (N2O) gas, nitric oxide (NO), oxygen (O2) plasma, nitrous oxide (N2O) plasma, nitric oxide (NO) plasma, and ozone (O3) plasma. In the step of injecting the oxygen-containing gas into the chamber, the film formed on the inner wall or part of the chamber may contain ruthenium (Ru), and the film formed on the inner wall or part of the chamber may include the step of vaporizing the ruthenium (Ru) into ruthenium tetroxide (RuO4) using the oxygen-containing gas.

[0061] The above chlorine-containing gas may include one or more of chlorine (Cl2) gas and chlorine (Cl2) plasma. In the step of injecting the chlorine-containing gas into the chamber, the method may include the step of replacing ruthenium dioxide (RuO2) that was not converted into ruthenium tetroxide (RuO4) by the oxygen-containing gas with ruthenium chloride (RuClx) or ruthenium chloride oxide (RuClOx) using the chlorine-containing gas.

[0062] Immediately after the oxidation / substitution process, an inert gas purge step and / or a base pumping step may be further included to remove oxygen / RuClx attached to the surface of the chamber wall. The inert gas purge step may remove oxygen / RuClx attached to the surface of the chamber wall by injecting an inert gas (Ar, He, N2) into the chamber. The base pumping step may reduce pressure and remove attached oxygen / RuClx attached to the surface of the chamber wall by performing exhaust pumping while stopping the injection of external gas.

[0063] FIG. 3 is a flowchart illustrating a ruthenium (Ru) deposition chamber cleaning method according to one embodiment of the present invention.

[0064] Referring to FIG. 3, first, the chamber can heat the susceptor to a first deposition temperature and heat the chamber to the same or similar temperature as the first deposition temperature (S80). The first deposition temperature may be 300 to 400 degrees Celsius (S80). Alternatively, the first deposition temperature may be 300 to 400 degrees Celsius. The temperature of the chamber and the temperature of the susceptor may be substantially the same. The chamber may be a conductive chamber or a quartz chamber. The conductive chamber may be maintained at 300 to 400 degrees Celsius by a heating heater. The susceptor may be maintained at 300 to 400 degrees Celsius by a heating heater.

[0065] Next, a Ru metal film can be formed on a substrate using a chemical vapor deposition or metal-organic chemical vapor deposition process with a Ru-containing gas in the chamber (S90). If a RuO2 film is to be formed, an additional O2 gas or ozone gas can be used to form the RuO2 film. The Ru deposition process can be performed to achieve a predetermined thickness.

[0066] Subsequently, a chamber cleaning process may be performed. The ruthenium (Ru) deposition chamber cleaning method comprises the steps of: vaporizing ruthenium (Ru) deposited on the inner wall of the chamber in which the ruthenium (Ru) deposition process was performed into ruthenium tetroxide (RuO4) using an oxygen-containing gas (S112); reducing ruthenium dioxide (RuO2) that was not converted into ruthenium tetroxide (RuO4) by the oxygen-containing gas into ruthenium (Ru) using a hydrogen-containing gas (S116); and vaporizing the reduced ruthenium (Ru) into ruthenium tetroxide (RuO4) using an oxygen-containing gas (S112).

[0067] A first step cleaning process (oxidation process) is performed on Ru(s) using O2 or O3 or O2 plasma or O3 plasma for a first process time (S112). The oxygen-containing gas may be at least one of oxygen (O2) gas, ozone (O3) gas, oxygen (O2) plasma, and ozone (O3) plasma.

[0068] The first process time of O2, O3, O2 plasma, or O3 plasma varies depending on the temperature of the chamber, and as the temperature of the chamber increases, the process time becomes shorter. The first process time may be several seconds to tens of seconds. To form the plasma, the chamber may include a plasma source. The plasma source may be a capacitively coupled plasma source or an inductively coupled plasma source. The first process time of the first stage cleaning process may coincide with the time at which RuO2 (solid) is formed. The first process time of the first stage cleaning process can be experimentally determined by confirming that RuO2 (solid) is formed under various conditions and is no longer cleaned. While the oxygen plasma or ozone plasma is operating, the chamber and the susceptor mounting the substrate may be maintained at the same temperature as the Ru deposition process. Accordingly, the time consumed by temperature changes of the chamber and the susceptor may be reduced. Meanwhile, the temperature of the chamber and the susceptor is maintained at 300 to 400 degrees Celsius, so that some of the ruthenium Ru (solid) attached to the chamber wall is converted into RuO2 (solid) by O2 or O3 or O2 plasma or O3 plasma, and the cleaning process may not proceed further. The chamber is a metal chamber, and the inner wall may be coated with a metal oxide (e.g., Al2O3). The chamber may be heated by a heating element placed outside the chamber. The susceptor may be heated independently by a susceptor heating element placed inside the susceptor.

[0069] Next, a step of checking whether the cleaning of the chamber wall is completed may be included (S114). The method of checking the completion of cleaning may use a deposition sensor such as a quartz crystal sensor, an optical sensor using surface reflection, etc. Alternatively, the number of oxidation and reduction cycles may be determined by experimental results.

[0070] Since a portion of the Ru(s) surface is converted into RuO2(s) by an oxidation process, a second cleaning step is performed for a second time to reduce RuO2(s) to Ru(s) by inducing a reduction reaction with H2 or H2 plasma (S116). The process time may be several seconds to tens of seconds. The temperature of the chamber and the susceptor may be maintained at 300°C to 400°C. The hydrogen-containing gas may be at least one of hydrogen (H2) gas and hydrogen (H2) plasma.

[0071] Before or after the reduction process to Ru(s), an inert gas purge step and / or a base pumping step may be further included to remove oxygen or hydrogen attached to the surface of the chamber wall. The inert gas purge step may remove oxygen attached to the surface of the chamber wall by injecting an inert gas (Ar, He, N2) into the chamber. The base pumping step may reduce pressure and remove attached oxygen or hydrogen attached to the surface of the chamber wall by performing exhaust pumping while the injection of external gas is stopped.

[0072] Next, a first cleaning process is performed to convert Ru(s) into RuO4(g) using O2, O3, O2 plasma, or O3 plasma (S112). The temperature of the chamber and the susceptor may be greater than 300 degrees Celsius and less than 400 degrees Celsius. Alternatively, the temperature of the chamber and the susceptor may be greater than 100 degrees Celsius and less than 400 degrees Celsius. By repeating the above process, Ru formed on the chamber wall and the side wall (part) of the susceptor can be removed. An inert gas purge step to remove hydrogen attached to the surface of the chamber wall may be further included.

[0073] Next, the method may include a step of checking whether the cleaning of the chamber wall is completed (S114). The method of checking the completion of cleaning may use a crystal sensor, a deposition sensor, an optical sensor using surface reflection, etc. If the cleaning of the chamber wall is completed, the deposition chamber may perform the deposition process again (S90).

[0074] FIG. 4 is a flowchart illustrating a ruthenium (Ru) deposition chamber cleaning method according to another embodiment of the present invention.

[0075] Referring to FIG. 4, first, the chamber can heat the susceptor to a first deposition temperature and heat the chamber to the same or similar temperature as the first deposition temperature (S80). The first deposition temperature may be 300 to 400 degrees Celsius. Or, the first deposition temperature may be 200 to 400 degrees Celsius. The temperature of the chamber and the temperature of the susceptor may be substantially the same. The chamber may be a conductive chamber or a quartz chamber. The conductive chamber may be maintained at 300 to 400 degrees Celsius by a heating heater.

[0076] Next, a Ru metal film can be formed on a substrate using a chemical vapor deposition or metal-organic chemical vapor deposition process with a Ru-containing gas in the chamber (S90). If a RuO2 film is to be formed, an additional O2 gas or ozone gas can be used to form the RuO2 film. The Ru deposition process can be performed to achieve a predetermined thickness.

[0077] Subsequently, a ruthenium (Ru) deposition chamber cleaning step may be performed. The ruthenium (Ru) deposition chamber cleaning method includes: a step (S112) of vaporizing ruthenium (Ru) deposited on the inner wall of the chamber in which the ruthenium (Ru) deposition process was performed into ruthenium tetroxide (RuO4) using an oxygen-containing gas; and a step (S216) of converting ruthenium dioxide (RuO2) that was not converted into ruthenium tetroxide (RuO4) by the oxygen-containing gas into ruthenium chloride (RuClx) or ruthenium chloride oxide (RuClOx) using a chlorine-containing gas.

[0078] The above oxygen-containing gas may be at least one of oxygen (O2) gas, ozone (O3) gas, oxygen (O2) plasma, and ozone (O3) plasma.

[0079] The above chlorine-containing gas may be at least one of chlorine (Cl2) gas, chlorine oxygen (Cl2+O2) gas, chlorine (Cl2) plasma, and chlorine oxygen (Cl2+O2) plasma.

[0080] The method further includes the step of heating the chamber to change the inner wall temperature of the chamber, wherein the inner wall temperature of the chamber may be 300 degrees Celsius to 400 degrees Celsius (S80).

[0081] The surface of RuO2 (solid) is removed by inducing a substitution reaction with Clx or Clx plasma, or Clx + Ox plasma, to form RuClx + Ox or RuClOx. Thus, Ru (solid) is exposed.

[0082] A first step cleaning process is performed for a first time period using Ru(s) as RuO4(g) with O2 or O3 or O2 plasma or O3 plasma (S112). The processing time of the O2 or O3 or O2 plasma or O3 plasma varies depending on the temperature of the chamber, and the processing time becomes shorter as the temperature of the chamber increases. The processing time may be several seconds to tens of seconds. The first processing time of the first step cleaning process can be experimentally determined by confirming that RuO2(solid) is formed under various conditions and can no longer be cleaned.

[0083] Next, a step of checking whether the cleaning of the chamber wall is completed may be included (S114). The method of checking the completion of cleaning may use a crystal sensor, a deposition sensor, an optical sensor using surface reflection, etc.

[0084] Since a portion of the Ru(s) surface is converted into RuO2(s) by an oxidation process, a second step is performed for two hours to remove RuO2(solid) by inducing a substitution reaction of RuO2(s) with Clx or Clx plasma, or Clx + Ox plasma, to form RuClx (gas) + Ox or RuClOx (gas) (S216). Chlorine-containing gas or chlorine-containing gas plasma may cause redeposition of ruthenium, but the Ru thin film deposited on the chamber wall can be removed by the repeated process.

[0085] Next, the first step (S112) can be performed again with Ru(solid) exposed. The first step cleaning process is performed for the first time using O2 or O3 or O2 plasma or O3 plasma to first clean Ru(s) into RuO4(g).

[0086] Next, the method may include a step of checking whether the cleaning of the chamber wall is completed (S114). The method of checking the completion of cleaning may use a crystal sensor, a deposition sensor, an optical sensor using surface reflection, etc. If the cleaning of the chamber wall is completed, the deposition chamber may perform the deposition process again (S90).

[0087] Before or after the substitution process with RuClx, an inert gas purging step and / or a base pumping step may be further included to remove oxygen or chlorine attached to the surface of the chamber wall. The inert gas purging step may remove oxygen or chlorine attached to the surface of the chamber wall by injecting an inert gas (Ar, He, N2) into the chamber. The base pumping step may reduce pressure and remove attached oxygen or chlorine attached to the surface of the chamber wall by performing exhaust pumping while the injection of external gas is stopped.

[0088] Although the present invention has been illustrated and described with respect to specific preferred embodiments, the present invention is not limited to these embodiments and includes all various forms of embodiments that can be implemented by a person skilled in the art without departing from the technical spirit of the present invention as claimed in the patent claims.

Claims

1. A cleaning method for a chamber on which a ruthenium-containing film has been deposited is: a) a step of injecting an oxygen-containing gas into the chamber; and b) a step of injecting a hydrogen-containing gas into the chamber; characterized by a chamber cleaning method.

2. In Paragraph 1, A chamber cleaning method characterized by repeating the cycle of steps a) and b) above.

3. In Paragraph 1, A chamber cleaning method characterized in that the above oxygen-containing gas comprises one or more of oxygen (O2) gas, ozone (O3) gas, nitrous oxide (N2O) gas, nitric oxide (NO), oxygen (O2) plasma, nitrous oxide (N2O) plasma, nitric oxide (NO) plasma and ozone (O3) plasma.

4. In Paragraph 1, A chamber cleaning method characterized in that the above hydrogen-containing gas comprises one or more of hydrogen (H2) gas and hydrogen (H2) plasma.

5. In Paragraph 1, A chamber cleaning method characterized by the cleaning temperature inside the chamber being 100 degrees Celsius to 400 degrees Celsius.

6. In Paragraph 1, In the step of injecting an oxygen-containing gas into the chamber, The film formed on the inner wall or part of the chamber contains ruthenium (Ru), and A chamber cleaning method characterized by including the step of vaporizing ruthenium (Ru) into ruthenium tetroxide (RuO4) using an oxygen-containing gas to form a film on the inner wall or part of the chamber.

7. In Paragraph 1, In the step of injecting a hydrogen-containing gas into the chamber, A chamber cleaning method characterized by including the step of reducing ruthenium dioxide (RuO2), which is not converted into ruthenium tetroxide (RuO4) by the oxygen-containing gas, to ruthenium (Ru) using a hydrogen-containing gas.

8. A cleaning method for a chamber on which a ruthenium-containing film has been deposited is: a) a step of injecting an oxygen-containing gas into the chamber; and b) a step of injecting a chlorine-containing gas into the chamber; characterized by a chamber cleaning method.

9. In Paragraph 8, A chamber cleaning method characterized by repeating the cycle of steps a) and b) above.

10. In Paragraph 8, A chamber cleaning method characterized in that the above oxygen-containing gas comprises one or more of oxygen (O2) gas, ozone (O3) gas, nitrous oxide (N2O) gas, nitric oxide (NO), oxygen (O2) plasma, nitrous oxide (N2O) plasma, nitric oxide (NO) plasma and ozone (O3) plasma.

11. In Paragraph 8, A chamber cleaning method characterized in that the above-mentioned chlorine-containing gas comprises one or more of chlorine (Cl2) gas and chlorine (Cl2) plasma.

12. In Paragraph 8, A chamber cleaning method characterized by the cleaning temperature inside the chamber being 100 degrees Celsius to 400 degrees Celsius.

13. In Paragraph 8, In the step of injecting an oxygen-containing gas into the chamber, The film formed on the inner wall or part of the chamber contains ruthenium (Ru), and A chamber cleaning method characterized by including the step of vaporizing ruthenium (Ru) into ruthenium tetroxide (RuO4) using an oxygen-containing gas to form a film on the inner wall or part of the chamber.

14. In Paragraph 8, In the step of injecting a chlorine-containing gas into the chamber, A chamber cleaning method characterized by including the step of replacing ruthenium dioxide (RuO2), which is not converted into ruthenium tetroxide (RuO4) by the oxygen-containing gas, with ruthenium chloride (RuClx) or ruthenium chloride oxide (RuClOx) using a chlorine-containing gas.

15. A step of vaporizing ruthenium (Ru) deposited on the inner wall of a chamber in which a ruthenium (Ru) deposition process is performed into ruthenium tetroxide (RuO4) using an oxygen-containing gas; A step of reducing ruthenium dioxide (RuO2), which is not converted into ruthenium tetroxide (RuO4) by the oxygen-containing gas, to ruthenium (Ru) using a hydrogen-containing gas; and A method for cleaning a ruthenium (Ru) deposition chamber, comprising the step of vaporizing the above-mentioned reduced ruthenium (Ru) into ruthenium tetroxide (RuO4) using an oxygen-containing gas.

16. In Paragraph 15, A method for cleaning a ruthenium (Ru) deposition chamber, characterized in that the oxygen-containing gas comprises at least one of oxygen (O2) gas, ozone (O3) gas, oxygen (O2) plasma, and ozone (O3) plasma.

17. In Paragraph 15, A method for cleaning a ruthenium (Ru) deposition chamber, characterized in that the above hydrogen-containing gas comprises at least one of hydrogen (H2) gas and hydrogen (H2) plasma.

18. A step of vaporizing ruthenium (Ru) deposited on the inner wall of a chamber in which a ruthenium (Ru) deposition process is performed into ruthenium tetroxide (RuO4) using an oxygen-containing gas; and A method for cleaning a ruthenium (Ru) deposition chamber, comprising the step of converting ruthenium dioxide (RuO2) that is not converted into ruthenium tetroxide (RuO4) by the oxygen-containing gas into ruthenium chloride (RuClx) or ruthenium chloride oxide (RuClOx) using a chlorine-containing gas.

19. In Paragraph 18, A method for cleaning a ruthenium (Ru) deposition chamber, characterized in that the oxygen-containing gas comprises at least one of oxygen (O2) gas, ozone (O3) gas, oxygen (O2) plasma, and ozone (O3) plasma.

20. In Paragraph 18, A method for cleaning a ruthenium (Ru) deposition chamber, characterized in that the above-mentioned chlorine-containing gas comprises at least one of chlorine (Cl2) gas, chlorine and oxygen-containing gas, chlorine plasma, and chlorine and oxygen-containing gas plasma.

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