Substrate processing method

Abstract

The present invention provides a substrate processing method. The substrate processing method may: load a substrate into a processing space in a process chamber; generate plasma by supplying a process gas containing a first gas and a second gas to the process chamber; remove a removal target film on the substrate in the processing space by using the plasma; calculate data related to a state of the plasma present in the processing space and a removal rate of the removal target film while changing a supply ratio of the first gas and the second gas; and set, on the basis of the data, the supply ratio of the first gas and the second gas supplied to the process chamber.

Description

Substrate processing method

[0001] The present invention relates to a substrate processing method capable of increasing the removal rate of a film formed on a substrate.

[0002] Plasma refers to an ionized gaseous state composed of ions, radicals, and electrons, and is generated by very high temperatures, strong electric fields, or RF electromagnetic fields. Semiconductor device manufacturing processes include plasma processes that treat substrates by reacting plasma with them.

[0003] Most substrate processing devices performing plasma processes utilize Optical Emission Spectroscopy (OES) technology to detect the start and end points of the plasma processing. The spectrometer used to detect these points is installed to face the chamber's viewport. The spectrometer identifies the start and end points of the process from light within a set wavelength range generated by the reaction between the plasma and the film on a substrate, such as a wafer.

[0004] Meanwhile, a method is known for generating plasma using a mixed gas containing chlorine (Cl2) and oxygen (O2) gases, and using this to remove a hard mask containing metal carbides, such as a WC substrate. When removing a hard mask containing metal carbides, the removal rate varies depending on the composition of the hard mask and the supply ratio of each gas included in the process gas; therefore, in order to remove the target film on the substrate at an optimal removal rate, it is necessary to calculate removal rate data based on the composition ratio of the process gas. Furthermore, there is a need for a process that rapidly removes the metal carbide hard mask while maintaining high selectivity for the underlying thin film.

[0005] One objective of the present invention is to provide a substrate processing method capable of calculating a process gas supply ratio that maximizes the removal rate of a film to be removed.

[0006] In addition, the present invention has one objective of providing a substrate processing method capable of controlling the stripping speed of a hard mask thin film and controlling the selectivity ratio with respect to the underlying thin film.

[0007] In addition, the present invention has one objective of providing a substrate processing method capable of detecting abnormalities in process conditions and defects in the substrate.

[0008] The problems that the present invention aims to solve are not limited to those described above, and problems not mentioned will be clearly understood by those skilled in the art from this specification and the attached drawings.

[0009] The present invention provides a method for processing a substrate. The substrate processing method comprises introducing a substrate into a processing space within a process chamber, supplying a process gas including a first gas and a second gas to the process chamber to generate plasma, and using the plasma to remove a film to be removed on the substrate in the processing space, while calculating data related to the state of the plasma existing in the processing space and the removal rate of the film to be removed while varying the supply ratio of the first gas and the second gas, and setting the supply ratio of the first gas and the second gas supplied to the process chamber based on the data.

[0010] According to one embodiment, the calculation of the data may include the step of measuring the ratio of the light intensity of the elemental radicals of the first gas and the elemental radicals of the second gas contained in the plasma or the removal rate of the film to be removed through an optical emission spectrometer (OES) connected to the process chamber and storing it as reference data.

[0011] According to one embodiment, the film to be removed includes a hard mask layer, the hard mask layer includes a metal carbide, and the removal rate of the film to be removed may mean the strip speed of the hard mask layer.

[0012] According to one embodiment, the first gas may be chlorine (Cl2) gas, and the second gas may be oxygen (O2) gas.

[0013] According to one embodiment, the process gas may further include argon (Ar) gas.

[0014] According to one embodiment, the supply ratio of the first gas and the second gas that maximizes the removal rate of the membrane to be removed can be calculated using the data, and the process gas can be set to be supplied according to the calculated supply ratio.

[0015] According to one embodiment, the removal target film on the substrate can be removed by supplying the process gas according to the set supply ratio of the process gas.

[0016] According to one embodiment, when removing a target film on a substrate by supplying the process gas according to the set supply ratio of the process gas, the ratio of the amount of light of each elemental radical included in the plasma is checked, and an abnormality in the process condition can be detected by comparing the checked ratio of light with the reference data.

[0017] According to one embodiment, the process gas is supplied according to the set supply ratio of the process gas to remove the film to be removed on the substrate, and then the removal rate of the substrate is checked, and the defect of the substrate can be detected by comparing the checked removal rate with the reference data.

[0018] The present invention also provides a method for processing a substrate. The substrate processing method comprises introducing a substrate into a processing space within a process chamber, supplying a process gas containing a first gas and a second gas to the process chamber to generate plasma, and using the generated plasma to remove a film to be removed on the substrate in the processing space within the process chamber, while calculating data related to the state of the plasma existing in the processing space and the removal rate of the film to be removed while varying the supply ratio of the first gas and the second gas, calculating the supply ratio of the first gas and the second gas that maximizes the removal rate of the film to be removed using the data, and setting the process gas to be supplied to the process chamber according to the calculated supply ratio to remove the film to be removed, wherein the film to be removed is a hard mask layer containing a metal carbide, and the removal rate of the film to be removed refers to the strip speed of the hard mask layer, and the first gas may be chlorine (Cl2) gas and the second gas may be oxygen (O2) gas.

[0019] According to one embodiment, the calculation of the data may include the step of measuring the ratio of the light intensity of the elemental radicals of the first gas and the elemental radicals of the second gas contained in the plasma or the removal rate of the film to be removed through an optical emission spectrometer (OES) connected to the process chamber and storing it as reference data.

[0020] According to one embodiment, the process gas may further include argon gas.

[0021] According to one embodiment, when removing a target film on a substrate by supplying the process gas according to the set supply ratio of the process gas, the ratio of the amount of light of each elemental radical included in the plasma is checked, and an abnormality in the process condition can be detected by comparing the checked ratio of light with the reference data.

[0022] According to one embodiment, the process gas is supplied according to the set supply ratio of the process gas to remove the film to be removed on the substrate, and then the removal rate of the substrate is checked, and the defect of the substrate can be detected by comparing the checked removal rate with the reference data.

[0023] According to one embodiment of the present invention, a process gas supply ratio can be calculated to maximize the removal rate of the membrane to be removed.

[0024] In addition, according to one embodiment of the present invention, the strip speed of the hard mask thin film can be controlled, and the selectivity ratio with respect to the lower thin film can be controlled.

[0025] In addition, according to one embodiment of the present invention, abnormalities in process conditions and defects in the substrate can be detected.

[0026] The effects of the present invention are not limited to the effects described above, and unmentioned effects will be clearly understood by those skilled in the art from this specification and the attached drawings.

[0027] The various features and benefits of the non-limiting embodiments of this specification may become more apparent from a review of the detailed description in conjunction with the accompanying drawings. The accompanying drawings are provided for illustrative purposes only and should not be construed as limiting the claims. Unless expressly stated otherwise, the accompanying drawings are not to be drawn to scale. For clarity, various dimensions in the drawings may be exaggerated.

[0028] Figure 1 is a diagram showing a hard mask thin film formed on a substrate.

[0029] FIG. 2 is a drawing showing a substrate processing apparatus according to one embodiment of the present invention.

[0030] FIG. 3 is a flowchart of a substrate processing method according to one embodiment of the present invention.

[0031] Figure 4 is a flowchart for the removal rate data acquisition step of Figure 3.

[0032] Figure 5 is a flowchart for the substrate processing step of Figure 3.

[0033] Figure 6 is a diagram showing the state in which plasma is generated in the processing space.

[0034] Figure 7 is a diagram showing the measurement of plasma generated in the processing space using a measuring unit.

[0035] Figure 8 shows a graph of the light intensity ratio according to the process gas supply ratio and a graph of the substrate removal rate according to the process gas supply ratio.

[0036] Figure 9 is a graph showing the metal carbide removal rate and the light intensity ratio for O and Cl elements in the etching section of the graph in Figure 8, normalized to min-max.

[0037] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. Exemplary embodiments are provided to ensure that the present disclosure is thorough and will fully convey its scope to those skilled in the art. To provide a complete understanding of the embodiments of the present disclosure, many specific details, such as examples of specific components, devices, and methods, are presented. It will be apparent to those skilled in the art that specific details are not necessary, that exemplary embodiments may be implemented in many different forms, and that neither should be interpreted as limiting the scope of the present disclosure. In some exemplary embodiments, known processes, known device structures, and known technologies are not described in detail.

[0038] The terms used herein are merely for describing specific exemplary embodiments and are not intended to limit exemplary embodiments. Singular expressions or expressions where singularity is not specified, as used herein, are intended to include plural expressions unless the context clearly indicates otherwise. The terms “comprising,” “comprising,” “having,” and “having” are open-ended and thus specify the presence of the mentioned features, components, steps, operations, elements, and / or components, and do not exclude the presence or addition of one or more other features, components, steps, operations, elements, components, and / or groups thereof. Method steps, processes, and operations in this specification are not to be interpreted as necessarily being performed in the specific order discussed or described unless the order of performance is specified. Additionally, additional or alternative steps may be selected.

[0039] When an element or layer is referred to as being "on," "connected," "combined," "attached," "adjacent," or "covering" another element or layer, it may be directly on, connected to, combined with, attached to, adjacent to, or covering said other element or layer, or intermediate elements or layers may exist. Conversely, when an element is referred to as being "directly on," "directly connected to," or "directly combined" with another element or layer, it should be understood that intermediate elements or layers do not exist. Throughout the specification, the same reference numerals refer to the same elements. The term "and / or" as used in the present invention includes all combinations and non-combinations of one or more of the listed items.

[0040] Although terms such as first, second, third, etc., may be used to describe various elements, regions, layers, and / or sections in the present invention, it should be understood that these elements, regions, layers, and / or sections are not limited by these terms. These terms are used merely to distinguish one element, region, layer, or section from another element, region, layer, or section. Accordingly, the first element, first region, first layer, or first section discussed below may be referred to as the second element, second region, second layer, or second section without departing from the teachings of the exemplary embodiments.

[0041] Spatially relative terms (e.g., "below," "under," "lower," "above," "top," etc.) may be used for convenience of explanation to describe the relationship between one element or feature and another element(s) or feature(s) as illustrated in the drawings. It should be understood that spatially relative terms are intended to include not only the orientations illustrated in the drawings but also other orientations of the device in use or operation. For example, if the device in the drawings is inverted, elements described as "below" or "under" other elements or features will be oriented "above" other elements or features. Thus, the term "below" may include both upper and lower orientations. The device may be oriented differently (rotated 90 degrees or in a different orientation), and the spatially relative descriptive terms used in the present invention may be interpreted accordingly.

[0042] It should be understood that there may be some inaccuracy when the terms "identical" or "same" are used in the description of the embodiments. Therefore, if one element or value is referred to as identical to another element or value, it should be understood that said element or value is identical to another element or value within a manufacturing or operating tolerance (e.g., ±10%).

[0043] Where the words “approximately” or “substantially” are used in this specification with respect to figures, it should be understood that such figures include a manufacturing or operational tolerance (e.g., ±10%) of the figures mentioned. Additionally, where the words “generally” and “substantially” are used with respect to geometric forms, it should be understood that while geometric accuracy is not required, freedom of form (latitude) is within the scope of disclosure.

[0044] Unless otherwise defined, all terms used in the present invention (including technical and scientific terms) have the same meaning as generally understood by those skilled in the art to which the exemplary embodiments belong. Furthermore, including terms defined in commonly used dictionaries, terms should be interpreted as having a meaning consistent with that meaning in the context of the relevant technology, and should not be interpreted in an ideal or overly formal sense unless explicitly defined in the present invention. Hereinafter, embodiments of the present invention will be described with reference to FIGS. 1 through 9.

[0045] In the substrate to be processed described below, a pattern (1) may be formed on the substrate as shown in FIG. 1, and a hard mask layer thin film, i.e., a hard mask thin film (2), may be formed on the pattern (1). The substrate of FIG. 1 may, for example, have a photoresist layer deposited on the hard mask thin film (2), and after the photoresist is patterned and developed, the exposed hard mask film under the photoresist pattern may be removed. The hard mask thin film (2) may be a thin film containing a metal carbide. The metal carbide may be, for example, tungsten carbide (WC), titanium carbide (TiC), etc. The hard mask thin film (2) may contain impurities such as some boron (B) and nitrogen (N). FIG. 1 is illustrated as a hard mask thin film (2) containing tungsten carbide (WC).

[0046] FIG. 2 is a drawing showing a substrate processing apparatus according to an embodiment of the present invention. Referring to FIG. 2, a substrate processing apparatus (10) according to an embodiment of the present invention may include a process chamber (100) and a controller (200).

[0047] The process chamber (100) can perform a plasma treatment process on the substrate (W). The process chamber (100) can perform a strip process or an etch process to remove a thin film on the substrate (W). Hereinafter, the process chamber (100) will be described as an example of performing a strip process to remove a metal carbide hard mask thin film (2) on the substrate (W) of FIG. 1 using plasma. However, it is not limited thereto, and the process chamber (100) can perform various types of processes, such as an ashing process to remove a photoresist film on the substrate or an etch process to etch a pattern (1) formed on the lower part of the metal carbide hard mask thin film (2).

[0048] The removal rate, which is the speed at which the film to be removed is removed, may mean the strip rate (SR) of the film when the film to be removed is a hard mask film (2).

[0049] The process chamber (100) includes a housing (110) defining a processing space (112), a chuck (120), a view port (130), a measuring unit (140), a gas supply unit (150), and a plasma unit (160).

[0050] A substrate (W) can be processed in the processing space (112). The processing space (112) can be exhausted by an exhaust device (not shown), such as a pump. By providing a reduction in pressure to the processing space (112) through the exhaust device, the pressure in the processing space (112) can be adjusted to a set pressure.

[0051] The chuck (120) can support the substrate (W) in the processing space (112). The chuck (120) can chuck the substrate (W) while processing of the substrate (W) by plasma is performed. The chuck (120) can chuck the substrate (W) using electrostatic force. The chuck (120) may be an electrostatic chuck. The chuck (120) may be a lower electrode. Power may be applied to the chuck (120). For example, high-frequency power applied by the lower power source (122) may be transmitted to the chuck (120). In addition, a matching device (not shown) may be installed between the lower power source (122) and the chuck (120) so that matching can be performed with respect to the high-frequency power applied by the lower power source (122).

[0052] A view port (130) may be installed on the side of the housing (110). The view port (130) may be formed of a transparent material so that the processing space (112) of the process chamber (100) can be monitored from the outside. For example, the view port (130) may be formed of a transparent quartz material. The view port (130) may be formed in various shapes. For example, the view port (130) may be formed in a cylindrical shape.

[0053] A measurement unit (140) may be fixedly installed on one side of the process chamber (100). The measurement unit (140) may receive light generated by the plasma. The measurement unit (140) may measure and analyze the amount of light from the plasma generated in the processing space (112) of the process chamber (100). The measurement unit (140) may measure the optical spectrum or wavelength of the processing space (112) in real time through a view port (130), and may identify the state of the plasma and the gas contributing to the reaction using the measured optical spectrum or wavelength. The measurement unit (140) may include an Optical Emission Spectroscope (OES). Hereinafter, the measurement unit (140) will be described as an example of an OES. The OES can measure the amount of light from the plasma (P) by observing the processing space (112). Since the OES is a known technology, a detailed description is omitted.

[0054] A gas supply unit (150) can supply process gas to a processing space (112). The gas supply unit (150) may include a gas supply line (152) and a gas source (154). Process gas stored in the gas source (154) can be supplied to the processing space (112) through the gas supply line (152). The process gas may include at least one of Cl2, O2, Ar, and F2. Although only one gas source (154) is shown in FIG. 2, it may be composed of multiple gas sources (154) to correspond to the process gas being supplied.

[0055] A plasma unit (160) can generate plasma in a processing space (112). The plasma unit (160) forms an electric field in the processing space (112), and the formed electric field can excite the process gas supplied to the processing space (112) to generate plasma. The plasma unit (160) may include a coil (162), a matching unit (164), and an RF power source (166). The coil (162) may be configured to wrap around the upper part of the process chamber (100). The RF power source (166) may apply an RF voltage to the coil (162). The RF power source (166) may be called an upper power source. The matching unit (164) may perform impedance matching with respect to the RF power source (166).

[0056] The process chamber (100) may be a capacitively coupled plasma (CCP) type plasma device. However, it is not limited to this, and the process chamber (100) may be an inductively coupled plasma (ICP) type plasma device.

[0057] The controller (200) may be provided with a process controller comprising a microprocessor (computer) that executes control of the components of the substrate processing device, a user interface comprising a keyboard for which an operator performs command input operations to manage the substrate processing device, a display for visualizing and displaying the operating status of the substrate processing device, a control program for executing processing in the substrate processing device under the control of the process controller, and a memory unit storing a program for executing processing in each component according to various data and processing conditions, i.e., a processing recipe. Additionally, the user interface and the memory unit may be connected to the process controller. The processing recipe may be stored in a storage medium within the memory unit, and the storage medium may be a hard disk, a portable disk such as a CD-ROM or DVD, or a semiconductor memory such as a flash memory.

[0058] Below, an embodiment of a method for processing a substrate using the substrate processing apparatus of FIG. 2 is described.

[0059] The substrate processing process according to the substrate processing method described below may be an etching process for etching a thin film of the substrate. In the following examples, the film to be removed is a metal carbide hard mask thin film, and the substrate processing process is a stripping process for stripping the metal carbide hard mask thin film. As described above, the substrate (W) may include a hard mask thin film of a metal carbide such as tungsten carbide (WC).

[0060] FIG. 3 is a flowchart of a substrate processing method according to one embodiment of the present invention.

[0061] Referring to FIG. 3, a substrate processing method according to one embodiment of the present invention includes a removal rate data acquisition step (S100) and a substrate processing step (S200). The removal rate data acquisition step (S100) is a step of measuring the removal rate of a substrate (W) and the state of a plasma while varying the supply ratio of a process gas supplied to a process chamber (100), obtaining removal rate data according to the supply ratio of the process gas from the measured data, and setting the supply ratio of the process gas supplied to the process chamber (100) in the substrate processing step (S200) based on the obtained removal rate data.

[0062] The substrate processing step (S200) is a step of processing a substrate (W) by supplying process gas to a process chamber (100) according to the supply ratio of process gas set in the removal rate data acquisition step (S100) and generating plasma (P).

[0063] Hereinafter, the removal rate data acquisition step (S100) will be described in detail with reference to FIGS. 4 and FIGS. 6 to 9, and the substrate processing step (S200) will be described in detail with reference to FIGS. 5 to 9.

[0064] Figure 4 is a flowchart for the removal rate data acquisition step of Figure 3.

[0065] Referring to FIG. 4, the removal rate data acquisition step (S100) includes the steps of substrate introduction (S110), process gas supply (S120), plasma generation (S130), plasma measurement (S140), removal rate data calculation (S150), and process gas supply ratio setting (S160). The steps may be performed sequentially.

[0066] In the substrate introduction (S110) step, the substrate (W) may be introduced into the processing space (112) of the process chamber (100) by a transport robot (not shown). The substrate (W) introduced into the processing space (112) may be placed on a chuck (120). The chuck (120) can chuck the substrate (W), which may be a wafer, by generating an electrostatic force. The substrate (W) introduced into the processing space (112) in the substrate introduction (S110) step of the removal rate data acquisition step (S100) may be a substrate (W) having the same material composition ratio and thin film configuration as the substrate (W) introduced into the processing space (112) in the substrate processing step (S200) described later. The substrate (W) introduced into the processing space (112) in the removal rate data acquisition step (S100) may be a test substrate prepared to set the optimal process gas supply ratio through prior data acquisition. In the following description, the substrate (W) introduced into the processing space (112) during the removal rate data acquisition step (S100) and the substrate (W) introduced into the processing space (112) during the substrate processing step (S200) will not be distinguished. However, if it is necessary to distinguish between these substrates, the substrate (W) introduced into the processing space (112) during the removal rate data acquisition step (S100) will be referred to as a test substrate, and the substrate (W) introduced into the processing space (112) during the substrate processing step (S200) will be referred to as an actual substrate.

[0067] When the substrate (W) is brought into the processing space (112), the process gas supply (S120) and plasma generation (S130) steps are performed. In the process gas supply (S120) step, a gas supply unit (150) can supply process gas to the processing space (112). The process gas includes a first gas and a second gas. The first gas may be chlorine (Cl2) gas, and the second gas may be oxygen (O2) gas. The process gas may further include an inert gas, such as argon (Ar) gas. The process gas may further include a fluorine-based gas. The fluorine-based gas may be, for example, CF4, SF6, NF3, C2F6, etc.

[0068] The supply ratio of the process gas supplied by the gas supply unit (150) to the processing space (112), that is, the supply ratio of the first gas and the second gas included in the process gas, can be fixed. The gas supply unit (150) can supply the first gas and the second gas according to the set supply ratio.

[0069] When process gas is supplied to the processing space (112), the plasma generation (S130) step is performed. FIG. 6 is a diagram showing the state in which plasma is generated in the processing space.

[0070] Referring further to FIG. 6, in the plasma generation (S130) step, the plasma unit (160) can generate plasma (P) by forming an electric field in the processing space (112) to excite the process gas supplied to the processing space (112). In this step, the internal pressure of the processing space (112) can be adjusted to a set value.

[0071] When processing the substrate (W) with the generated plasma (P), a strip is formed in the processing space (112) by the radicals and ions of the plasma. While the strip is being formed, the hard mask thin film formed on the substrate (W) can be removed.

[0072] In the plasma measurement (S140) step, the state of the plasma (P) within the processing space (112) is measured using a measurement unit (140). FIG. 7 is a diagram showing the measurement of the plasma generated in the processing space using the measurement unit. Referring further to FIG. 7, the measurement unit (140) can measure the amount of light from the plasma (P) and byproducts within the processing space (112) using OES. The measurement unit (140) can measure the wavelengths of the elemental radicals of the first gas and the elemental radicals of the second gas contained in the plasma (P) using OES. When the first gas is chlorine (Cl2) gas and the second gas is oxygen (O2) gas, the measurement unit (140) can obtain measurement data by observing the wavelengths and amount of light from the oxygen radicals and chlorine radicals inside the plasma (P) using OES. From the measured data, the density of each elemental radical present inside the plasma can be measured.

[0073] In the step of calculating removal rate data (S150), the removal rate data of the substrate (W) according to the supply ratio of the process gas is calculated using the measurement data obtained in the plasma measurement (S140) step and the removal rate value of the substrate (W).

[0074] The step of calculating removal rate data (S150) can be performed multiple times while varying the supply ratio of the process gas supplied by the gas supply unit (150) to the processing space (112), that is, the supply ratio of the first gas and the second gas included in the process gas.

[0075] FIG. 8 shows a graph of the light intensity ratio according to the process gas supply ratio and a graph of the substrate removal rate according to the process gas supply ratio. With further reference to FIG. 8, the step of calculating removal rate data (S150) will be explained in detail.

[0076] The x-axis of the graph in Fig. 8 represents the supply ratio of the first gas and the second gas supplied by the gas supply unit (150) to the processing space (112).

[0077] The x-axis value representing the supply ratio of the first gas and the second gas can be expressed as the value obtained by dividing the supply amount of the second gas by the sum of the supply amount of the first gas and the supply amount of the second gas. When the process gas contains a small amount of argon (Ar) gas, the supply ratio of the first gas and the second gas can be expressed in comparison with a certain amount of argon (Ar) gas, and the x-axis value can be calculated by combining these equations.

[0078] In addition, the left and right y-axis shown in the graph of Fig. 8 represent the ratio of light intensity of chlorine element radicals and oxygen element radicals, respectively, and the strip rate (SR) for the metal carbide hard mask film (2) which is the target film for removal of the substrate (W), respectively.

[0079] As described above, a specific supply ratio of the first gas and the second gas is set, and the steps of substrate introduction (S110), process gas supply (S120), plasma generation (S130), and plasma measurement (S140) are performed sequentially for one substrate (W). Through this, in the plasma measurement (S140) step, the elemental radical light amount (I) of the first gas corresponding to the specific supply ratio of the first gas and the second gas is Cl ) and the amount of light (I) of the elemental radicals of the second gas O Ratio data can be obtained. Also, when the processing of the substrate (W) is completed, removal rate data for the film to be removed from the substrate (W), that is, strip speed (Å / min) data for the metal carbide hard mask film (2), can be obtained.

[0080] The data obtained in the plasma measurement (S140) step can be represented as light quantity ratio and removal rate graphs corresponding to the supply ratio of the specific first gas and second gas of FIG. 8, respectively.

[0081] For example, the leftmost point in the light intensity ratio graph of FIG. 8 is the light intensity ratio data of the elemental radicals of the first gas and the elemental radicals of the second gas obtained by setting the x-axis value, which is the supply ratio of the first gas and the second gas, to be approximately 5%, and then sequentially performing the steps of substrate introduction (S110), process gas supply (S120), plasma generation (S130), and plasma measurement (S140) for one substrate (W). Also, the leftmost point in the removal rate graph of FIG. 8 is the removal rate (Å / min) data for the metal carbide hard mask thin film (2) of the substrate (W) obtained by setting the process gas supply ratio to be approximately 5%, and then sequentially performing the steps of substrate introduction (S110), process gas supply (S120), plasma generation (S130), and plasma measurement (S140) for one substrate (W).

[0082] In the step of calculating removal rate data (S150), the processing for the corresponding substrate (W) is terminated, and the supply ratio of the first gas and the second gas supplied to the processing space (112) for another substrate (W) is changed, and the steps of substrate introduction (S110), process gas supply (S120), plasma generation (S130), and plasma measurement (S140) are performed sequentially. If the above process is repeated for a plurality of substrates (W) while changing the supply ratio of the first gas and the second gas supplied to the processing space (112), two graphs each containing a plurality of points can be obtained as shown in FIG. 8.

[0083] Looking at the removal rate graph in Fig. 8, it can be seen that as the x value increases, that is, as the ratio of the oxygen (O2) gas supply amount to the chlorine (Cl2) gas supply amount in the process gas increases, the removal rate of the metal carbide thin film on the substrate (W) tends to increase, reaches a maximum value at the point where the x value is A, and becomes 0 at points where the x value exceeds A. Since the point where the removal rate of the film to be removed is maximized is when the x value is A, the supply ratio of the first gas and the second gas at point A can be calculated to determine the supply ratio of the first gas and the second gas that maximizes the removal rate of the film to be removed.

[0084] Additionally, from the graph in FIG. 8, depending on the supply ratio of the process gas, the section where the removal target film can be removed, that is, the section where the metal carbide hard mask film (2) can be stripped, can be identified. In FIG. 8, the region where the x value is A or less is the section where the metal carbide hard mask film (2) can be stripped, and the region where the x value is greater than A is the section where the metal carbide hard mask film (2) cannot be stripped. The reason why such a section where stripping is impossible occurs is that when the oxygen (O2) gas supply ratio in the process gas exceeds a certain value, the supplied oxygen can grow the oxide film layer of the substrate (W) and act as a barrier that prevents the stripping of the metal carbide hard mask film (2).

[0085] In the step of calculating removal rate data (S150), a minimum-maximum normalization process may be performed to verify the correlation between the light intensity ratio data of the elemental radicals of the first gas and the elemental radicals of the second gas obtained in the plasma measurement (S140) step and the removal rate data of the film to be removed.

[0086] FIG. 9 is a graph showing the metal carbide removal rate in the etching section of FIG. 8 and the light intensity ratio for O and Cl elements, normalized to min-max. Referring to FIG. 9, the slopes of the two graphs after the normalization process are almost identical, which indirectly confirms that the ratio of O and Cl elements has a significant influence on the metal carbide removal rate. Therefore, by observing the light intensity ratio for oxygen and chlorine elements, the removal rate of the substrate (W), that is, the removal rate of the hard mask thin film (2) on the substrate (W), can be indirectly confirmed.

[0087] By measuring the ratio of oxygen and chlorine elements through the measuring unit (140), it is possible to determine whether the removal of the target film, that is, the stripping of the metal carbide hard mask film (2), is being performed properly.

[0088] The light quantity ratio data value and the removal rate value of the elemental radicals of each first gas and second gas obtained in the step of calculating removal rate data (S150) are stored as reference data corresponding to the process gas supply ratio. This will be described later.

[0089] Based on the graph of Fig. 8 obtained in the step of calculating removal rate data (S150), a process gas supply ratio setting (S160) is performed. In the step of setting the process gas supply ratio (S160), based on the data calculated in the step of calculating removal rate data (S150), the supply ratio of the process gas supplied to the processing space (112) in the substrate processing step (S200) is set.

[0090] For example, in the substrate processing step (S200), the supply ratio of the process gas supplied to the processing space (112) is set to the supply ratio of the first gas and the second gas at point A in FIG. 8, and after supplying the process gas according to the supply ratio, the plasma is excited to process the substrate (W), thereby maximizing the removal rate of the substrate (W).

[0091] When the removal rate data acquisition step (S100) is completed, the substrate processing step (S200) is performed.

[0092] Figure 5 is a flowchart for the substrate processing step of Figure 3.

[0093] Referring to FIG. 5, an embodiment of the substrate processing step (S200) will be described.

[0094] In the substrate introduction (S210) step, the substrate (W) may be introduced into the processing space (112) of the process chamber (100) by a transport robot (not shown). The substrate (W) introduced into the processing space (112) may be placed on a chuck (120). The chuck (120) may generate an electrostatic force to chuck the substrate (W), which may be a wafer. The substrate (W) introduced into the processing space (112) in the substrate introduction (S210) step may be a substrate (W) having the same thin film composition as the substrate (W) introduced into the processing space (112) in the removal rate data acquisition step (S100) described above. In other words, the substrate (W) introduced into the processing space (112) in the substrate introduction (S210) step may be a substrate (W) having the same material composition ratio as the substrate (W) introduced into the processing space (112) in the removal rate data acquisition step (S100).

[0095] When the substrate (W) is brought into the processing space (112), the process gas supply (S220) and plasma generation (S230) steps are performed. In the process gas supply (S220) step, the gas supply unit (150) can supply process gas to the processing space (112).

[0096] The supply ratio of the process gas supplied by the gas supply unit (150) to the processing space (112), that is, the supply ratio of the first gas and the second gas included in the process gas, is the supply ratio set in the above-described process gas supply ratio setting (S160) step.

[0097] For example, the supply ratio of the first gas and the second gas included in the process gas supplied to the processing space (112) in the process gas supply (S220) step may be the supply ratio of the first gas and the second gas at point A of FIG. 8.

[0098] When process gas is supplied to the processing space (112), the plasma generation (S230) step is performed. Since the plasma generation (S230) step is the same process as the aforementioned plasma generation (S130) step, a detailed description is omitted.

[0099] In the substrate processing and plasma measurement (S240) step, the substrate (W) is processed with plasma (P), and the state of the plasma (P) within the processing space (112) is measured using a measurement unit (140). Since the process of measuring the state of the plasma (P) within the processing space (112) using the measurement unit (140) follows the same process as the aforementioned plasma measurement (S140) step, a detailed explanation is omitted.

[0100] The measurement unit (140) obtains measurement data by observing the wavelength and light intensity of oxygen radicals and chlorine radicals inside the plasma (P) using OES, and the elemental radical light intensity (I) of the first gas when performing an etching process on an actual substrate (W). Cl ) and the amount of light (I) of the elemental radicals of the second gas O Ratio data can be obtained.

[0101] The controller (200) obtains the elemental radical light amount (I) of the first gas. Cl ) and the amount of light (I) of the elemental radicals of the second gas O ) Check the ratio to determine whether the light intensity ratio value matches the reference data (S250).

[0102] The reference data is the light quantity ratio data value and removal rate value of the elemental radicals of each first gas and second gas corresponding to the process gas supply ratio, obtained in the step of calculating removal rate data (S150).

[0103] For example, if the supply ratio of the process gas is the supply ratio of the first gas and the second gas at point A in Fig. 8, the reference data refers to the y-values ​​of the two graphs at point A.

[0104] As previously described, the removal rate of the substrate (W) can be indirectly confirmed by observing the ratio of light intensity to oxygen and chlorine elements, and the substrate (W) processed in the removal rate data acquisition step (S100) and the substrate (W) processed in the substrate processing step (S200) are substrates (W) having the same material composition ratio.

[0105] Therefore, if there is no abnormality in the process conditions, the elemental radical light amount (I) of the first gas when performing the strip process on the actual substrate (W) Cl ) and the amount of light (I) of the elemental radicals of the second gas O The ratio data matches the reference data, and accordingly, the removal rate of the actual substrate (W) will also match the removal rate of the test substrate (W).

[0106] If the light intensity ratio data verified for the actual substrate (W) does not match the reference data, it means that the process condition for the actual substrate (W) has changed compared to the process condition for the test substrate (W), so it can be inferred that there is a problem with the process condition, such as the process chamber (100) or process pressure. In such a case, the controller (200) can detect an abnormality in the process condition and take measures such as generating an alarm.

[0107] If the light intensity ratio data verified for the actual substrate (W) matches the reference data, processing is performed on the substrate (W), and when the processing is finished, the substrate (W) is released (S260).

[0108] The removal rate of the actual substrate (W) that has been removed can be checked, and compared with the removal rate of the test substrate (W) to determine if the two values ​​match. If the removal rate of the removed substrate (W) matches the removal rate of the test substrate (W), it can be presumed that the removal of the target film on the substrate (W) was performed without any issues. If the removal rate confirmed for the actual substrate (W) does not match the reference data, it can be presumed that the material composition ratio of the test substrate (W) that was brought into the processing space (112) in the removal rate data acquisition step (S100) and the actual substrate (W) processed in the substrate processing step (S200) are different. For example, it can be presumed that a defect occurred in the substrate (W) due to a problem with a process performed before the substrate (W) was brought into the process chamber (100), such as a deposition process on the substrate (W).

[0109] A substrate processing method according to one embodiment of the present invention can determine the removal rate according to the ratio (light intensity) of Cl2 and O2 gases dissociated by measuring and analyzing the plasma (P) generated in the processing space (112) through a measuring unit (140), and can predict the removal rate of the substrate (W) by measuring the light intensity. In addition, the point where the hard mask thin film (2) is not stripped when the ratio of oxygen (O2) gas in the process gas increases can be identified through the wavelength ratio or light intensity ratio or normalized light intensity ratio or wavelength ratio measured through the measuring unit (140).

[0110] The present invention can calculate the supply ratio of process gas corresponding to the removal rate of the film to be removed by obtaining light quantity ratio and removal rate data according to the supply ratio of process gas through the measurement unit (140). Through this, the strip speed of the hard mask film (2) can be controlled, and the selectivity ratio with respect to the lower film or pattern (1) can be controlled.

[0111] Since the present invention can calculate the supply ratio of process gas that maximizes the removal rate of the film to be removed, it is possible to perform a strip process having a high selectivity ratio for the underlying film while maximizing the removal rate of the hard mask film.

[0112] The present invention can detect abnormalities in process conditions and defects in the substrate (W) by obtaining light quantity ratio and removal rate data according to the supply ratio of process gas and verifying the light quantity ratio and removal rate data while processing the actual substrate (W) with the set supply ratio of process gas.

[0113] In the above-described embodiment, the process chamber (100) is described as performing a strip process to remove a metal carbide thin film on a substrate (W) using plasma. However, it is not limited thereto, and the process chamber (100) can perform various types of processes, such as an ashing process to remove a photoresist film or an etching process to etch a target film, such as a pattern (1) formed on the underside of the metal carbide thin film.

[0114] In the above-described embodiment, the removal rate was explained as an example of meaning the strip rate (SR) for the thin film. However, when the process chamber (100) performs an etching process to etch the film to be removed, the removal rate may also mean the etch rate (ER) for the film to be removed.

[0115] The above detailed description is illustrative of the present invention. Furthermore, the foregoing describes preferred embodiments of the present invention, and the present invention may be used in various other combinations, modifications, and environments. That is, modifications or alterations are possible within the scope of the concept of the invention disclosed herein, the scope equivalent to the written disclosure, and / or the scope of the art or knowledge. The foregoing embodiments describe the best state for implementing the technical concept of the present invention, and various modifications required in specific fields of application and uses of the present invention are possible. Accordingly, the above detailed description of the invention is not intended to limit the present invention to the disclosed embodiments. Furthermore, the appended claims should be interpreted as including other embodiments.

Claims

1. Regarding the method of processing the substrate, Bring the substrate into the processing space inside the process chamber, and A process gas comprising a first gas and a second gas is supplied to the above process chamber to generate plasma, and Remove the film to be removed on the substrate in the processing space using the above plasma, While varying the supply ratio of the first gas and the second gas, data related to the state of the plasma existing in the processing space and the removal rate of the target film to be removed is calculated, and A substrate processing method for setting the supply ratio of the first gas and the second gas supplied to the process chamber based on the above data.

2. In Paragraph 1, The calculation of the above data is, A substrate processing method comprising the step of measuring the ratio of the light intensity of the elemental radicals of the first gas and the elemental radicals of the second gas contained in the plasma, or the removal rate of the film to be removed, through an optical emission spectrometer (OES) connected to the process chamber, and storing the result as reference data.

3. In Paragraph 2, The above-mentioned removal target film includes a hard mask layer, and The above hard mask layer contains metal carbide, and The removal rate of the above-mentioned film to be removed refers to the stripping speed of the above-mentioned hard mask layer, Substrate processing method.

4. In Paragraph 3, A substrate treatment method in which the first gas is chlorine (Cl2) gas and the second gas is oxygen (O2) gas.

5. In Paragraph 4, The above process gas is a substrate processing method that further includes argon (Ar) gas.

6. In Paragraph 2, A substrate processing method that calculates the supply ratio of the first gas and the second gas to maximize the removal rate of the target film using the above data, and sets the process gas to be supplied according to the calculated supply ratio.

7. In Paragraph 6, A substrate processing method for removing the target film on the substrate by supplying the process gas according to the set supply ratio of the process gas.

8. In Paragraph 2, When removing a target film on a substrate by supplying the process gas according to the set supply ratio of the process gas, the ratio of the light intensity of each elemental radical included in the plasma is checked, and A substrate processing method for detecting abnormalities in process conditions by comparing the confirmed light intensity ratio with the reference data.

9. In Paragraph 2, After removing the film to be removed on the substrate by supplying the process gas according to the set supply ratio of the process gas, the removal rate of the substrate is checked, and A substrate processing method for detecting defects in the substrate by comparing the confirmed removal rate with the reference data.

10. In a method for processing a substrate, Bring the substrate into the processing space inside the process chamber, and A process gas comprising a first gas and a second gas is supplied to the above process chamber to generate plasma, and Using the generated plasma, remove the film to be removed on the substrate in the processing space within the process chamber, While varying the supply ratio of the first gas and the second gas, data related to the state of the plasma existing in the processing space and the removal rate of the target film to be removed is calculated, and Using the above data, calculate the supply ratio of the first gas and the second gas that maximizes the removal rate of the membrane to be removed, and set up to remove the membrane to be removed by supplying the process gas to the process chamber according to the calculated supply ratio. The above-mentioned removal target film is a hard mask layer containing metal carbide, and The removal rate of the above-mentioned film to be removed refers to the stripping speed of the above-mentioned hard mask layer, and A substrate treatment method in which the first gas is chlorine (Cl2) gas and the second gas is oxygen (O2) gas.

11. In Paragraph 10, The calculation of the above data is, A substrate processing method comprising the step of measuring the ratio of the light intensity of the elemental radicals of the first gas and the elemental radicals of the second gas contained in the plasma, or the removal rate of the film to be removed, through an optical emission spectrometer (OES) connected to the process chamber, and storing the result as reference data.

12. In Paragraph 10, The above process gas is a substrate processing method that further includes argon gas.

13. In Paragraph 11, When removing a target film on a substrate by supplying the process gas according to the set supply ratio of the process gas, the ratio of the light intensity of each elemental radical included in the plasma is checked, and A substrate processing method for detecting abnormalities in process conditions by comparing the confirmed light intensity ratio with the reference data.

14. In Paragraph 11, After removing the film to be removed on the substrate by supplying the process gas according to the set supply ratio of the process gas, the removal rate of the substrate is checked, and A substrate processing method for detecting defects in the substrate by comparing the confirmed removal rate with the reference data.

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