Plasma processing apparatus and plasma processing method

Abstract

A plasma treatment device disclosed herein includes a chamber, a plasma generation unit, a plurality of annular electromagnet units, a power supply, at least one optical sensor, and a control unit. The plurality of electromagnet units are coaxially provided with respect to the axis line passing through an inner space of the chamber. Said at least one optical sensor detects the emission intensity distribution of the plasma in the radial direction in the chamber 10. The control unit controls, according to the emission intensity distribution of the plasma, the power supply so as to adjust current supplied to each of the plurality of annular electromagnet units.

Description

[Technical Field]

[0001] SUMMARY OF THE INVENTION Exemplary embodiments of the present disclosure relate to a plasma processing apparatus and a plasma processing method. [Background technology]

[0002] A plasma processing apparatus is used in plasma processing of a substrate. The plasma processing apparatus includes a chamber, a mounting table, a gas supply unit, and a high-frequency power supply. The mounting table is provided in the chamber. The gas supply unit supplies gas into the chamber. The high-frequency power supply supplies high-frequency power to generate plasma from the gas in the chamber. Patent Document 1 listed below discloses a plasma processing apparatus that uses multiple electromagnets to adjust the distribution of plasma density in the chamber. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] Japanese Patent Application Laid-Open No. 2014-158005 Summary of the Invention [Problem to be solved by the invention]

[0004] The present disclosure provides a technique for controlling the distribution of plasma density based on the emission intensity of the plasma. [Means for solving the problem]

[0005] In one exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus includes a chamber, a substrate support, a gas supply unit, a plasma generation unit, a plurality of annular electromagnet units, at least one optical sensor, at least one power supply, and a controller. The chamber has an internal space. The substrate support is disposed within the internal space of the chamber. The gas supply unit is configured to supply a process gas into the internal space of the chamber. The plasma generation unit is configured to generate plasma from the process gas within the internal space of the chamber. The plurality of annular electromagnet units are disposed above the internal space of the chamber and coaxially with respect to an axis passing through the internal space. Each of the plurality of annular electromagnet units includes one or more electromagnets. The at least one optical sensor is configured to detect an emission intensity distribution of the plasma in the internal space along a radial direction relative to the axis. The at least one power supply is configured to individually supply current to the plurality of annular electromagnet units. The controller is configured to adjust the current supplied from the at least one power supply to each of the plurality of annular electromagnet units based on the emission intensity distribution of the plasma detected by the at least one optical sensor. [Effects of the Invention]

[0006] According to one exemplary embodiment, it is possible to control the distribution of plasma density based on the plasma emission intensity. [Brief explanation of the drawings]

[0007] [Figure 1] 1 is a flow chart illustrating a plasma processing method according to an exemplary embodiment. [Figure 2] 1 illustrates a plasma processing apparatus according to an exemplary embodiment; [Figure 3] 1 is a cross-sectional view of an electrostatic chuck in a plasma processing apparatus according to an exemplary embodiment. [Figure 4] 1 is a plan view showing an arrangement of a plurality of electromagnets in a plasma processing apparatus according to an exemplary embodiment; [Figure 5]1 illustrates a substrate processing system according to an exemplary embodiment. [Figure 6] Each of FIGS. 6(a) and 6(b) is a flowchart of a part of a process that can be employed in a plasma processing method according to one example embodiment. [Figure 7] FIG. 1 illustrates a plasma processing apparatus according to another exemplary embodiment. [Figure 8] FIG. 10 is a plan view showing an arrangement of a plurality of electromagnets in a plasma processing apparatus according to another exemplary embodiment. DETAILED DESCRIPTION OF THE INVENTION

[0008] Various exemplary embodiments are described below.

[0009] In one exemplary embodiment, a plasma processing apparatus is provided. The plasma processing apparatus includes a chamber, a substrate support, a gas supply unit, a plasma generation unit, a plurality of annular electromagnet units, at least one optical sensor, at least one power supply, and a controller. The chamber has an internal space. The substrate support is disposed within the internal space of the chamber. The gas supply unit is configured to supply a process gas into the internal space of the chamber. The plasma generation unit is configured to generate plasma from the process gas within the internal space of the chamber. The plurality of annular electromagnet units are disposed above the internal space of the chamber and coaxially with respect to an axis passing through the internal space. Each of the plurality of annular electromagnet units includes one or more electromagnets. The at least one optical sensor is configured to detect an emission intensity distribution of the plasma in the internal space along a radial direction relative to the axis. The at least one power supply is configured to individually supply current to the plurality of annular electromagnet units. The controller is configured to adjust the current supplied from the at least one power supply to each of the plurality of annular electromagnet units based on the emission intensity distribution of the plasma detected by the at least one optical sensor.

[0010] In one exemplary embodiment, each of the plurality of annular electromagnet units may include at least one annular electromagnet.

[0011] In one exemplary embodiment, each of the plurality of annular electromagnet units may include a plurality of electromagnets arranged along a circumferential direction with respect to the axis, and each of the plurality of electromagnets may include a bobbin having a cylindrical shape and a coil wound around the bobbin.

[0012] In one exemplary embodiment, the plasma processing apparatus may include a plurality of optical sensors as the at least one optical sensor. The plurality of optical sensors may be provided above the internal space. The plurality of optical sensors may be configured to detect an emission intensity distribution of the plasma. The plurality of optical sensors may be arranged along a radial direction.

[0013] In one exemplary embodiment, at least one optical sensor may be provided along a sidewall of the chamber.

[0014] In one exemplary embodiment, the control unit may be configured to adjust the current supplied to the plurality of annular electromagnet units so as to reduce a difference between the luminous intensity distribution detected by the at least one optical sensor and a desired luminous intensity distribution.

[0015] In one exemplary embodiment, the substrate support may include a temperature control mechanism configured to adjust the temperature distribution of a substrate placed on the substrate support.

[0016] In one exemplary embodiment, the gas supply may be configured to adjust the radial distribution of the process gas flow rate.

[0017] In one exemplary embodiment, the controller may be configured to adjust the current supplied from the at least one power supply to each of the plurality of annular electromagnet units based on a shape of the substrate, and the shape of the substrate may be measured by a shape measuring device inside or outside the chamber.

[0018] In another exemplary embodiment, a plasma processing method using a plasma processing apparatus is provided. The plasma processing method includes the above-described chamber, a substrate support, a gas supply unit, a plasma generation unit, a plurality of annular electromagnet units, at least one optical sensor, and at least one power supply. The plasma processing method includes a step (a) of detecting the emission intensity distribution of the plasma using the at least one optical sensor. The plasma processing method further includes a step (b) of adjusting the current supplied from the at least one power supply to each of the plurality of annular electromagnet units based on the emission intensity distribution of the plasma.

[0019] In one exemplary embodiment, in step ST(a), the currents supplied to the respective annular electromagnet units may be adjusted based on the plasma state, which may be the emission intensity distribution of the plasma, or the density or amount distribution of chemical species in the plasma determined from the emission intensity distribution.

[0020] In one exemplary embodiment, the plasma processing method may further include measuring a state of plasma generated in the chamber using a sensor substrate mounted on the substrate support, and adjusting currents supplied from at least one power supply to each of the plurality of annular electromagnet units based on the plasma state measured using the sensor substrate.

[0021] In one exemplary embodiment, the sensor substrate may be configured to measure the distribution of the flux of ions or radicals supplied to the sensor substrate as a plasma state.

[0022] In one exemplary embodiment, a substrate shape corresponding to a plasma state based on an emission intensity distribution acquired using at least one optical sensor may be identified from pre-prepared data. The data is data indicating a relationship between a plurality of plasma states and substrate shapes obtained in each of the plurality of plasma states, and is prepared in advance. In step (b), the currents supplied from at least one power supply to the plurality of annular electromagnet units may be adjusted so as to reduce a difference between the identified substrate shape and a desired substrate shape.

[0023] In one exemplary embodiment, the plasma processing method further includes a step (c) of processing a substrate with the plasma generated in the chamber. The shape of the processed substrate may be measured in the step (c). In the step (b), currents supplied from at least one power source to each of the plurality of annular electromagnet units may be adjusted so as to reduce a difference between a plasma state based on the emission intensity distribution acquired by the at least one optical sensor and a desired plasma state, and to reduce a difference between the measured shape of the substrate and the desired shape of the substrate.

[0024] Various exemplary embodiments will be described in detail below with reference to the drawings, in which the same or equivalent parts are designated by the same reference numerals.

[0025] 1 is a flow chart showing a plasma processing method according to one example embodiment. The plasma processing method shown in FIG. 1 (hereinafter referred to as "method MT") is performed using a plasma processing apparatus.

[0026] 2 is a diagram illustrating a plasma processing apparatus according to an exemplary embodiment. The plasma processing apparatus 1 illustrated in FIG. 2 can be used in the method MT. The plasma processing apparatus 1 is a capacitively coupled plasma processing apparatus. The plasma processing apparatus 1 includes a chamber 10.

[0027] The chamber 10 has a substantially cylindrical shape and provides an internal space 10s therein. An axis AX shown in FIG. 2 is a central axis of the chamber 10 and the internal space 10s and extends vertically. The chamber 10 may include a chamber body 12. The chamber body 12 has a substantially cylindrical shape. The chamber body 12 is formed from a metal such as aluminum and is grounded. The internal space 10s is provided inside the chamber body 12. The pressure in the internal space 10s can be reduced by an exhaust device 14.

[0028] The sidewall of the chamber 10 provides a passage 10p. The substrate W passes through the passage 10p when being transferred between the inside and outside of the chamber 10. The passage 10p is opened and closed by a gate valve 10g. The gate valve 10g is provided along the sidewall of the chamber 10.

[0029] The plasma processing apparatus 1 further includes a substrate support 16. The substrate support 16 is provided in the chamber 10. The substrate support 16 is configured to support a substrate W placed thereon. The central axis of the substrate support 16 coincides with the axis AX.

[0030] In one embodiment, the substrate support 16 may include a base 18 and an electrostatic chuck 20. The base 18 is made of a conductive material, such as aluminum, and has a generally disk shape.

[0031] The electrostatic chuck 20 is provided on a base 18. FIG. 3 is a cross-sectional view of an electrostatic chuck in a plasma processing apparatus according to an exemplary embodiment. As shown in FIG. 3, a substrate W is placed on the electrostatic chuck 20 so that its center is located on an axis AX. The substrate W may have a diameter of, for example, 300 mm. The substrate support 16 may be configured to further support an edge ring ER placed thereon. The substrate W is placed on the electrostatic chuck 20 and within a region surrounded by the edge ring ER.

[0032] The electrostatic chuck 20 has a main body 20m and an electrode 20e. The main body 20m is made of a dielectric material such as aluminum nitride or aluminum oxide. The main body 20m has a substantially disk shape. The electrode 20e is a conductive film and is provided inside the main body 20m. The electrode 20e is connected to a power supply 20p via a switch 20s. When a DC voltage from the power supply 20p is applied to the electrode 20e, an electrostatic attractive force is generated between the electrostatic chuck 20 and the substrate W. Due to the generated electrostatic attractive force, the substrate W is attracted to the electrostatic chuck 20 and held by the electrostatic chuck 20.

[0033] The substrate support 16 may have a temperature control mechanism. The temperature control mechanism of the substrate support 16 is configured to be able to adjust the temperature distribution of the substrate W. In one embodiment, the substrate support 16 may have a plurality of heaters HT as the temperature control mechanism. Each of the plurality of heaters HT is, for example, a resistance heating element. Each of the plurality of heaters HT generates heat by receiving an electric current individually supplied from a heater controller HC. The plurality of heaters HT are arranged below a plurality of regions of the substrate W, respectively. The plurality of heaters HT may be provided within an electrostatic chuck 20, as shown in FIG. 3.

[0034] The plasma processing apparatus 1 further includes an upper electrode 22. The upper electrode 22 is provided above the substrate support 16. The upper electrode 22 closes the upper end opening of the chamber body 12. The upper electrode 22 also functions as a shower head. In one embodiment, the upper electrode 22 provides a plurality of gas diffusion chambers 22a to 22c and a plurality of gas holes 22h. The number of gas diffusion chambers may be any number equal to or greater than two.

[0035] The gas diffusion chambers 22a to 22c are concentrically arranged in the upper electrode 22. The central axes of the gas diffusion chambers 22a to 22c are axis AX. The gas diffusion chamber 22a is circular in plan view and is a space that intersects with the axis AX. The gas diffusion chambers 22b to 22c are substantially annular spaces. The gas diffusion chamber 22b is provided radially outward from the gas diffusion chamber 22a. The gas diffusion chamber 22c is provided radially outward from the gas diffusion chamber 22b. Each of the gas holes 22h extends downward from a corresponding one of the gas diffusion chambers 22a to 22c and opens toward the internal space 10s.

[0036] The plasma processing apparatus 1 further includes a gas supply unit 24. The gas supply unit 24 is configured to supply a processing gas into the chamber 10. In one embodiment, the gas supply unit 24 is configured to be able to adjust the flow rate distribution of the processing gas supplied to the substrate W along the radial direction of the substrate W. In one embodiment, the gas supply unit 24 is configured to supply the processing gas into the chamber 10 via the shower head described above, and is configured to individually supply the processing gas to each of the plurality of gas diffusion chambers 22a to 22c.

[0037] The gas supply unit 24 may include a gas source group 24a, a flow rate controller group 24b, a valve group 24c, and a flow splitter 24d. The gas source group 24a includes one or more gas sources. Gases from the one or more gas sources constitute a process gas. The flow rate controller group 24b includes one or more flow rate controllers. The valve group 24c includes one or more on-off valves. Each of the one or more gas sources in the gas source group 24a is connected to the flow splitter 24d via a corresponding flow rate controller in the flow rate controller group 24b and a corresponding on-off valve in the valve group 24c. The flow splitter 24d is configured to distribute the supplied process gas to the multiple gas diffusion chambers 22a to 22c. The flow splitter 24d is capable of adjusting the distribution ratio of the process gas to the multiple gas diffusion chambers 22a to 22c.

[0038] In the plasma processing apparatus 1, the process gas supplied to the gas diffusion chamber 22a is supplied to the central region of the substrate W through the plurality of gas holes 22h connected to the gas diffusion chamber 22a. The process gas supplied to the gas diffusion chamber 22b is supplied to the edge region of the substrate W through the plurality of gas holes 22h connected to the gas diffusion chamber 22b. The process gas supplied to the gas diffusion chamber 22c is supplied to the region radially outward from the edge of the substrate W through the plurality of gas holes 22h connected to the gas diffusion chamber 22c. The gas supply unit 24 can adjust the distribution ratio of the process gas to the plurality of gas diffusion chambers 22a to 22c using the flow splitter 24d, thereby adjusting the radial distribution of the process gas flow rate of the substrate W.

[0039] The plasma processing apparatus 1 further includes a high-frequency power supply 26. The high-frequency power supply 26 constitutes a plasma generation unit in one embodiment. The high-frequency power supply 26 is connected to a high-frequency electrode via a matching unit 26m. The high-frequency power supply 26 generates high-frequency power to be supplied to the high-frequency electrode. The high-frequency electrode may be an electrode within the substrate support 16. In one embodiment, the high-frequency electrode is the base 18. The high-frequency power generated by the high-frequency power supply 26 has a frequency suitable for generating plasma. This frequency is, for example, 100 MHz. The matching unit 26m has a matching circuit for matching the impedance of the load of the high-frequency power supply 26 to the output impedance of the high-frequency power supply 26. The high-frequency power supply 26 may be connected to the upper electrode 22. That is, the upper electrode 22 may be a high-frequency electrode.

[0040] The plasma processing apparatus 1 may further include a bias power supply 28. The bias power supply 28 is connected to a bias electrode of the substrate support 16 via a matcher 28m. The bias power supply 28 generates bias energy to be supplied to the bias electrode. The bias energy is supplied to the electrode of the substrate support 16 to attract ions to the substrate W. In one embodiment, the bias electrode is the base 18. The bias energy generated by the bias power supply 28 is high-frequency bias power or a voltage pulse that is generated intermittently or periodically. The matcher 28m has a matching circuit for matching the impedance of the load of the bias power supply 28 to the output impedance of the bias power supply 28.

[0041] In the plasma processing apparatus 1, a processing gas is supplied into the chamber 10 from a gas supply unit 24. The pressure inside the chamber 10 is reduced by an exhaust unit 14. High-frequency power is supplied to a high-frequency electrode from a high-frequency power supply 26. As a result, plasma is generated from the processing gas in the chamber 10. Then, chemical species such as radicals and ions from the plasma process the substrate W. For example, a film on the substrate W is etched. The energy of the ions supplied to the substrate W can be adjusted by bias energy from a bias power supply 28.

[0042] Hereinafter, reference will be made to FIG. 4 in addition to FIG. 1. FIG. 4 is a plan view showing the arrangement of multiple electromagnets in a plasma processing apparatus according to an exemplary embodiment. The plasma processing apparatus 1 further includes multiple electromagnets 30. The multiple electromagnets 30 are provided on the ceiling (upper electrode 22) of the chamber 10. The multiple electromagnets 30 include electromagnets 31 to 3N. Each of the multiple electromagnets 30 is formed by a coil wound around an axis AX. The multiple electromagnets 30 have different inner diameters and are provided concentrically. Some of the multiple electromagnets 30 are provided above the substrate W. One or more of the multiple electromagnets 30 may be provided above a region outside the edge of the substrate W. The multiple electromagnets 30 constitute multiple annular electromagnet units 30U. The multiple annular electromagnet units 30U are provided coaxially with respect to the axis AX. Each of the multiple annular electromagnet units 30U includes at least one corresponding electromagnet 30 among the multiple electromagnets 30.

[0043] The plasma processing apparatus 1 may further include a bobbin member 40. The bobbin member 40 may be made of a magnetic material. The bobbin member 40 includes bobbins 41 to 4N. The coils of the electromagnets 31 to 3N are wound around the bobbins 41 to 4N, respectively. The bobbins 41 to 4N are arranged concentrically, and their central axes are the axis line AX. The bobbin 41 has a cylindrical shape. The bobbins 42 to 4N have a cylindrical shape and are arranged radially outside the bobbin 41. The bobbin member 40 may further include a tubular portion 40e and a base portion 40b. The tubular portion 40e is arranged concentrically with the bobbins 41 to 4N and surrounds the electromagnet 3N radially outside the bobbin 4N. The base portion 40b has a substantially disk shape. The bobbins 41 to 4N and the cylindrical portion 40e are integrated with the base portion 40b and extend downward from the base portion 40b.

[0044] The plasma processing apparatus 1 further includes at least one power supply 50. The power supply 50 is configured to individually supply current to the coils of the multiple electromagnets 30 (or the multiple annular electromagnet units 30U). The current supplied from the power supply 50 to the coils of the multiple electromagnets 30 (or the multiple annular electromagnet units 30U) is, for example, a direct current. The current supplied by the power supply 50 to the coils of the multiple electromagnets 30 (or the multiple annular electromagnet units 30U) is individually controlled by a control unit Cnt, which will be described later.

[0045] Each of the multiple electromagnets 30 forms a magnetic field in the chamber 10 that is symmetrical with respect to the axis AX. A composite magnetic field is formed in the chamber 10 by the magnetic fields formed by the multiple electromagnets 30. This composite magnetic field is also symmetrical with respect to the axis AX. By controlling the current supplied to each of the multiple electromagnets 30 (or the multiple annular electromagnet units 30U), it is possible to adjust the magnetic field strength distribution in the radial direction with respect to the axis AX. This allows the plasma processing apparatus 1 to adjust the plasma density distribution in the chamber 10 in the radial direction of the substrate W.

[0046] The plasma processing apparatus 1 further includes one or more sensors 60. The one or more sensors 60 are configured to acquire the plasma state, i.e., the plasma condition, within the chamber 10. Each of the one or more sensors 60 is an optical sensor. The one or more sensors 60 detect the plasma emission intensity distribution within the chamber 10 along a radial direction relative to the axis AX. The one or more sensors 60 may include multiple sensors 60 provided above the internal space 10s. The multiple sensors 60 may be provided within the upper electrode 22. The multiple sensors 60 detect the plasma emission intensity distribution within the chamber 10 along a radial direction via the multiple gas holes 22h. Instead of or in addition to the multiple sensors 60, the one or more sensors 60 may include at least one sensor 60. The at least one sensor 60 is provided along a sidewall of the chamber 10 and detects the plasma emission intensity distribution within the chamber 10 along a radial direction via an optical window provided in the sidewall of the chamber 10.

[0047] In one embodiment, the plasma processing apparatus 1 may further include a shape measuring device 70 or a shape measuring device including a transmitter 70t and a receiver 70r. The shape measuring device 70 is a sensor configured to measure the shape of the substrate W (e.g., the in-plane distribution of the width of the opening in the mask) when the substrate W enters the internal space 10s from the passage 10p. The transmitter 70t transmits measurement light to the substrate W placed on the substrate support 16 through an optical window. The receiver 70r receives reflected light from the substrate W to measure the shape of the substrate W (e.g., the in-plane distribution of the width of the opening in the mask). Note that the shape measuring device may be provided above the internal space 10s when the top plate of the chamber 10 defining the internal space 10s is made of an optically transparent material. Alternatively, one or more sensors 60 may also function as the shape measuring device.

[0048] The plasma processing apparatus 1 further includes a control unit Cnt. The control unit Cnt is a computer equipped with a processor, a storage device, an input device, a display device, etc., and controls each unit of the plasma processing apparatus 1. Specifically, the control unit Cnt executes a control program stored in the storage device and controls each unit of the plasma processing apparatus 1 based on recipe data stored in the storage device. Under the control of the control unit Cnt, a process specified by the recipe data is executed in the plasma processing apparatus 1. Furthermore, as will be described later, the control unit Cnt controls the power supply 50 to adjust the current supplied to each of the multiple electromagnets 30 (or the multiple annular electromagnet units 30U) based on the plasma state (e.g., the plasma emission intensity distribution).

[0049] In one embodiment, the plasma processing apparatus 1 may constitute a part of a substrate processing system. FIG. 5 is a diagram illustrating a substrate processing system according to one exemplary embodiment. The substrate processing system (hereinafter referred to as "system 100") illustrated in FIG. 5 can be used in a method MT. The system 100 includes stages 122a-122d, containers 124a-124d, a loader module LM, load lock modules LL1 and LL2, a transfer module 121, and a process module PM.

[0050] The stages 122a to 122d are arranged along one edge of the loader module LM. The containers 124a to 124d are provided on the stages 122a to 122d, respectively. Each of the containers 124a to 124d can accommodate a substrate W. Each of the containers 124a to 124d is, for example, a container called a FOUP (Front-Opening Unified Pod).

[0051] The loader module LM has a chamber. The pressure in the chamber of the loader module LM is set to atmospheric pressure. The loader module LM provides a transfer robot Rb1 in the chamber. The transfer robot Rb1 is configured to transfer a substrate W between any one of the containers 124a to 124d and any one of the load lock modules LL1 and LL2. The transfer robot Rb1 is also configured to transfer a substrate W between any one of the load lock modules LL1 and LL2 and the optical observation device OC, and between the optical observation device OC and any one of the containers 124a to 124d.

[0052] The load lock modules LL1 and LL2 are connected to the loader module LM. Each of the load lock modules LL1 and LL2 provides a preliminary decompression chamber. The load lock modules LL1 and LL2 are connected to the transfer module 121.

[0053] The transfer module 121 has a chamber that can be decompressed. The transfer module 121 provides a transfer robot Rb2 in the chamber. The transfer module 121 is connected to a process module PM. The transfer robot Rb2 is configured to transfer a substrate W between either one of the load lock modules LL1 or LL2 and the process module PM. The process module PM is a plasma processing apparatus 1.

[0054] The system 100 further includes an optical observation device OC (shape measuring device). The substrate W is transported between the optical observation device OC and the process module PM by the transport robots Rb1 and Rb2. The optical observation device OC aligns the substrate W accommodated therein. Thereafter, the optical observation device OC measures the shape of the substrate W. For example, the optical observation device OC measures the in-plane distribution of widths of a plurality of openings formed in the substrate W by the process module PM (plasma processing device 1). The optical observation device OC may also measure the shape of the substrate W (for example, the in-plane distribution of widths of openings in a mask) before it is processed by the process module PM (plasma processing device 1).

[0055] The above-mentioned control unit Cnt controls the plasma processing apparatus 1, that is, the various parts of the process module PM as well as the various parts of the system 100. Data DT, which will be described later, is stored in a memory device of the control unit Cnt so as to be freely readable.

[0056] 1, the method MT will be described using the plasma processing apparatus 1. In the method MT, each component of the plasma processing apparatus 1 and each component of the system 100 can be controlled by a control unit Cnt.

[0057] In one embodiment, the method MT may include steps ST1 to ST4. In step ST1, a sensor substrate is loaded into the chamber 10. The sensor substrate may be loaded into the chamber 10 by a transfer robot Rb2. The sensor substrate is a substrate having substantially the same shape as the substrate W, and has a plurality of sensors arranged along its radial direction. In one embodiment, each of the plurality of sensors on the sensor substrate is configured to acquire the flux of ions or radicals. In this embodiment, the sensor substrate measures the distribution of the flux of ions or radicals supplied to it in a plasma state.

[0058] In the subsequent step ST2, plasma is generated in the chamber 10. In step ST2, a process gas or another gas is supplied from the gas supply unit 24 into the chamber 10. The pressure in the chamber 10 is adjusted to a specified pressure by the exhaust device 14. High-frequency power is supplied from the high-frequency power supply 26. In step ST2, bias energy may be supplied from the bias power supply 28. In step ST2, the gas supply unit 24, the exhaust device 14, the high-frequency power supply 26, and the bias power supply 28 are controlled by the control unit Cnt to generate plasma.

[0059] In the subsequent step ST3, the plasma state of the plasma generated in step ST2 is acquired by the sensor substrate. As described above, the plasma state can be the distribution of the flux of ions or radicals supplied to the sensor substrate.

[0060] In the subsequent step ST4, the current supplied from the power supply 50 to each of the electromagnets 30 (or each of the annular electromagnet units 30U) is adjusted based on the plasma state acquired using the sensor substrate. The current supplied from the power supply 50 to each of the electromagnets 30 (or each of the annular electromagnet units 30U) is controlled by the control unit Cnt. The current supplied to each of the electromagnets 30 (or each of the annular electromagnet units 30U) is adjusted so as to reduce the difference between the plasma state acquired using the sensor substrate and a desired plasma state. The desired plasma state is provided to the control unit Cnt of the plasma processing apparatus 1 as input data. The current to each of the electromagnets 30 (or each of the annular electromagnet units 30U) adjusted in step ST4 can be initially used in step ST12, which will be described later. The control unit Cnt can identify the current to each of the electromagnets 30 (or each of the annular electromagnet units 30U) using a table or function that identifies the current to each of the electromagnets 30 (or each of the annular electromagnet units 30U) from the plasma state acquired using the sensor substrate and the desired plasma state. This table or function is prepared in advance.

[0061] 1, the method MT includes steps ST11 to ST14. In one embodiment, steps ST11 to ST14 are performed after the sensor substrate is unloaded from the chamber 10.

[0062] In step ST11, a substrate W is loaded into the chamber 10. The substrate W is a substrate to be processed in step ST12. Before step ST11, the substrate W is accommodated in one of the containers 124a to 124d. The substrate W may be loaded into the chamber 10 by a transfer robot Rb2.

[0063] In the subsequent step ST12, plasma is generated in the chamber 10, and the substrate W is processed by the plasma. For example, the substrate W is etched. In step ST12, a processing gas is supplied from the gas supply unit 24 into the chamber 10. The pressure in the chamber 10 is adjusted to a specified pressure by the exhaust device 14. High-frequency power is supplied from the high-frequency power supply 26. In step ST12, bias energy may be supplied from the bias power supply 28. In step ST12, the gas supply unit 24, the exhaust device 14, the high-frequency power supply 26, and the bias power supply 28 are controlled by the control unit Cnt to generate plasma.

[0064] Step ST13 is performed while the substrate W is being processed with plasma in step ST12. In step ST13, the state of the plasma generated in the chamber 10 in step ST12, i.e., the plasma state, is acquired using one or more sensors 60. The plasma state acquired in step ST13 may be the emission intensity distribution of the plasma acquired using one or more sensors 60. Alternatively, the plasma state acquired in step ST13 may be the distribution of the density or amount of chemical species (e.g., radicals and / or ions) in the plasma, which is determined from the emission intensity distribution acquired using one or more sensors 60. The distribution of the density or amount of chemical species in the plasma is determined from the emission intensity distribution by an actinometry method.

[0065] Step ST14 is performed after the processing of the substrate W in step ST12 is completed. In step ST14, the substrate W is unloaded from the chamber 10. The substrate W may be unloaded from the chamber 10 by the transfer robot Rb2. The substrate W unloaded from the chamber 10 may be housed in any of the containers 124a to 124d.

[0066] The method MT further includes a step STC. The step STC is performed during or after the step ST12 (for example, after the step ST15 described below). In the step STC, the current supplied from the power supply 50 to each of the electromagnets 30 (or each of the annular electromagnet units 30U) is adjusted based on the plasma state acquired in the step ST13. In the step STC, the temperature distribution of the substrate W may be further adjusted by the temperature control mechanism of the substrate support 16. In the step STC, the gas supply unit 24 may further adjust the flow rate distribution of the process gas along the radial direction of the substrate W. In the step STC, the power supply 50, the temperature control mechanism of the substrate support 16, and the gas supply unit 24 are controlled by the control unit Cnt.

[0067] In one embodiment, the current supplied to each of the electromagnets 30 (or the multiple annular electromagnet units 30U) is adjusted so as to reduce the difference between the plasma state acquired in step ST13 and a desired plasma state. The desired plasma state is provided as input data to the control unit Cnt of the plasma processing apparatus 1. The control unit Cnt can specify the current to each of the multiple electromagnets 30 (or the multiple annular electromagnet units 30U) using a table or function that specifies the current to each of the multiple electromagnets 30 (or the multiple annular electromagnet units 30U) based on the plasma state acquired in step ST13 and the desired plasma state. This table or function is prepared in advance.

[0068] Alternatively, in step STC, the shape of the substrate W corresponding to the plasma state acquired in step ST13 may be determined from data DT prepared in advance. The shape of the substrate W is, for example, the distribution of the widths of multiple openings formed in the substrate W by plasma across the surface of the substrate W. The data DT indicates the relationship between multiple plasma states and the shapes of the substrate W obtained in each of the multiple plasma states. The currents supplied from the power supply 50 to each of the multiple electromagnets 30 (or the multiple annular electromagnet units 30U) may be adjusted in step STC to reduce the difference between the shape of the substrate W determined by referring to the data DT from the plasma state acquired in step ST13 and the desired shape of the substrate. The desired shape of the substrate is provided as input data to the control unit Cnt of the plasma processing apparatus 1. The control unit Cnt may determine the current to each of the multiple electromagnets 30 (or the multiple annular electromagnet units 30U) using a table or function that determines the current to each of the multiple electromagnets 30 (or the multiple annular electromagnet units 30U) based on the acquired shape of the substrate W and the desired shape of the substrate W. This table or function is prepared in advance.

[0069] The method MT further includes a step STJ. In the step STJ, it is determined whether a stop condition is satisfied. The stop condition is satisfied when there is no other substrate W to be processed. If the stop condition is not satisfied, processing from step ST11 is performed on another substrate W. On the other hand, if the stop condition is satisfied, the method MT ends.

[0070] The method MT may further include step ST15, which is performed after step ST12. In one embodiment, step ST15 is performed after step ST14. In step ST15, the shape of the substrate W processed in step ST12 is measured. The shape of the substrate W is, for example, the distribution of widths of a plurality of openings formed in the substrate W by plasma within the surface of the substrate W. The shape of the substrate W may be measured using an optical observation device OC. Alternatively, the shape of the substrate W may be measured using an imaging device such as a hyperspectral camera provided in the plasma processing apparatus 1.

[0071] In one embodiment, step STC may be performed after step ST15. In this case, the current supplied from the power supply 50 to each of the electromagnets 30 (or each of the annular electromagnet units 30U) is adjusted for the substrate W to be processed next. The current supplied from the power supply 50 to each of the electromagnets 30 (or each of the annular electromagnet units 30U) is adjusted so as to reduce the difference between the plasma state acquired in step ST13 and the desired plasma state and to reduce the difference between the measured shape of the substrate W and the desired shape of the substrate. The desired plasma state and the desired shape of the substrate are provided as input data to the control unit Cnt of the plasma processing apparatus 1. The control unit Cnt can determine the current to each of the electromagnets 30 (or each of the annular electromagnet units 30U) using a table or function that determines the current to each of the electromagnets 30 (or each of the annular electromagnet units 30U) based on the plasma state acquired in step ST13 and the desired plasma state, and the shape of the substrate W measured in step ST15 and the desired shape of the substrate W. This table or function is prepared in advance.

[0072] According to the method MT, a plasma state (e.g., a plasma emission intensity distribution) is acquired. Then, the currents supplied to each of the plurality of electromagnets 30 or the plurality of annular electromagnet units 30U are adjusted based on the acquired plasma state. As a result, the plasma density distribution is adjusted based on the plasma state. The plasma state is acquired, for example, while the substrate W is being processed by the plasma. Therefore, the plasma density distribution can be adjusted based on the plasma state when the substrate W is actually being processed.

[0073]

[0043] Referring now to Figure 6, (a) and (b) of Figure 6 are flow charts of some processes that may be employed in a plasma processing method according to an exemplary embodiment. The processes shown in (a) and (b) of Figure 6 can be employed in place of step ST11 in method MT.

[0074] 6(a) includes steps ST21, ST22, and STC. In step ST21, the substrate W is loaded into the chamber 10. In step ST22, the shape of the substrate W (e.g., the in-plane distribution of the width of the openings in the mask) is measured in the chamber 10. The shape of the substrate W is measured using the shape measuring device described above, such as the shape measuring device 70 including the transmitter 70t and the receiver 70r.

[0075] In step STC shown in FIG. 6(a), the current supplied from the power supply 50 to each of the electromagnets 30 (or each of the annular electromagnet units 30U) is adjusted. The current supplied from the power supply 50 to each of the electromagnets 30 (or each of the annular electromagnet units 30U) is adjusted so that a substrate having a desired shape is obtained after processing in step ST12 from the substrate W having the shape acquired in step ST22. The desired shape of the substrate after processing in step ST12 is provided as input data to the control unit Cnt of the plasma processing apparatus 1. The control unit Cnt can specify the current to each of the electromagnets 30 (or each of the annular electromagnet units 30U) using a table or function specifying the current to be supplied to the electromagnets 30 (or each of the annular electromagnet units 30U) so that a substrate having the desired shape is obtained by processing in step ST12 from the substrate W having the shape measured in step ST22. This table or function is prepared in advance.

[0076] 6(b) includes steps ST31, ST32, and STC. In step ST31, the shape of the substrate W (e.g., the in-plane distribution of the width of the openings in the mask) is measured outside the chamber 10. The shape of the substrate W is measured using, for example, an optical observation device OC. In the subsequent step ST32, the substrate W is loaded into the chamber 10.

[0077] In step STC shown in FIG. 6(b), the current supplied from the power supply 50 to each of the electromagnets 30 (or each of the annular electromagnet units 30U) is adjusted. The current supplied from the power supply 50 to each of the electromagnets 30 (or each of the annular electromagnet units 30U) is adjusted so that a substrate having a desired shape is obtained after processing in step ST12 from the substrate W having the shape acquired in step ST31. The desired shape of the substrate after processing in step ST12 is provided as input data to the control unit Cnt of the plasma processing apparatus 1. The control unit Cnt can specify the current to each of the electromagnets 30 (or each of the annular electromagnet units 30U) using a table or function specifying the current to be supplied to the electromagnets 30 (or each of the annular electromagnet units 30U) so that a substrate having the desired shape is obtained by processing in step ST12 from the substrate W having the shape measured in step ST31. This table or function is prepared in advance.

[0078] Reference will now be made to FIGS. 7 and 8. FIG. 7 is a diagram illustrating a plasma processing apparatus according to another exemplary embodiment. FIG. 8 is a plan view illustrating the arrangement of multiple electromagnets in a plasma processing apparatus according to another exemplary embodiment. The plasma processing apparatus 1A illustrated in FIGS. 7 and 8 can be used in the method MT. The plasma processing apparatus 1A differs from the plasma processing apparatus 1 in that it includes multiple electromagnets 30A instead of multiple electromagnets 30. The other configurations of the plasma processing apparatus 1A are the same as the corresponding configurations of the plasma processing apparatus 1.

[0079] A plurality of electromagnets 30A are provided on the ceiling (upper electrode 22) of the chamber 10. The plurality of electromagnets 30A are arranged along a plurality of concentric circles around the axis AX and in a radial direction (diameter) relative to the axis AX. One of the plurality of electromagnets 30A may be provided on the axis AX. The plurality of electromagnets 30A constitute a plurality of annular electromagnet units 30U. Each of the plurality of annular electromagnet units 30U is composed of a plurality of electromagnets 30A arranged along a corresponding one of the plurality of concentric circles.

[0080] Each of the multiple electromagnets 30A includes a bobbin 30b and a coil 30c. The bobbin 30b has a cylindrical shape and extends in the vertical direction. The bobbin 30b is made of, for example, a magnetic material. The coil 30c is wound around the bobbin 30b. That is, the coil 30c is provided around an axis extending in the vertical direction.

[0081] A current is individually supplied from a power supply 50 to each coil 30c of the plurality of electromagnets 30A (or the plurality of annular electromagnet units 30U). The current supplied to each coil 30c of the plurality of electromagnets 30A (or the plurality of annular electromagnet units 30U) can be controlled by a control unit Cnt. In the plasma processing apparatus 1A, a current of the same value and in the same direction is supplied to the coils 30c of the electromagnets 30A arranged along the same circle among the plurality of concentric circles.

[0082] In the plasma processing apparatus 1A, a composite magnetic field symmetrical with respect to the axis line AX is formed in the chamber 10 by the multiple electromagnets 30A. In addition, by controlling the current supplied to the multiple electromagnets 30A (or the multiple annular electromagnet units 30U), it is possible to adjust the magnetic field strength distribution in the radial direction with respect to the axis line AX. This allows the plasma processing apparatus 1 to adjust the plasma density distribution in the chamber 10 in the radial direction of the substrate W.

[0083] Although various exemplary embodiments have been described above, the present invention is not limited to the above-described exemplary embodiments, and various additions, omissions, substitutions, and modifications may be made. Furthermore, elements in different embodiments may be combined to form other embodiments.

[0084] For example, in each of the plasma processing apparatuses 1 and 1A, the plurality of electromagnets and the plurality of annular electromagnet units may be provided in the ceiling of the chamber 10 (upper electrode 22).

[0085] In another embodiment, the plasma processing apparatus may be a type other than the capacitively coupled type, such as an inductively coupled type plasma processing apparatus or an ECR (electron cyclotron resonance) plasma processing apparatus.

[0086] The present disclosure also includes the following further embodiments E1 to E10. [E1] A plasma processing method using a plasma processing apparatus, comprising: The plasma processing apparatus includes: a chamber; a substrate support disposed within the chamber; a gas supply configured to supply a process gas into the chamber; a plasma generating unit configured to generate a plasma from the process gas within the chamber; a plurality of electromagnets, each composed of a plurality of coils arranged coaxially with respect to a central axis passing vertically through the center of the substrate support, on a ceiling of the chamber, or a plurality of electromagnets, each having a coil arranged around an axis extending vertically, arranged on the ceiling along a plurality of concentric circles around the central axis and in a radial direction; a power source configured to individually supply current to the plurality of electromagnets; The plasma processing method comprises: (a) loading a substrate into the chamber; (b) treating the substrate with a plasma generated in the chamber; (c) acquiring plasma conditions using one or more sensors while the substrate is being processed by the plasma; (d) removing the substrate after the step of processing the substrate; Including, The steps (a) to (d) are performed sequentially on a plurality of substrates; The plasma treatment method includes: (e) adjusting the current supplied from the power source to each of the plurality of electromagnets based on the plasma state while (b) is being performed or after (b). The plasma processing method further comprises: [E2] the plasma state is an emission intensity distribution of the plasma or a distribution of density or amount of chemical species in the plasma obtained from the emission intensity distribution; The plasma processing method of embodiment E1. [E3] Before the step (a), a step of measuring a state of plasma generated in the chamber using a sensor substrate placed on the substrate support; adjusting the current supplied from the power supply to each of the plurality of electromagnets based on the plasma state measured using the sensor substrate; Further comprising: The plasma processing method of embodiment E1 or E2. [E4] The plasma processing method of embodiment E3, wherein the sensor substrate is configured to measure a distribution of a flux of ions or radicals supplied to the sensor substrate as the plasma state. [E5] The plasma processing method of any one of embodiments E1 to E4, wherein in (e), the current supplied from the power supply to each of the plurality of electromagnets is adjusted so as to reduce the difference between the plasma state acquired using the one or more sensors and a desired plasma state. [E6] A plasma processing method according to any one of embodiments E1 to E4, wherein the shape of the substrate corresponding to the plasma state acquired using the one or more sensors is identified from pre-prepared data showing the relationship between a plurality of plasma states and the shapes of the substrate obtained in each of the plurality of plasma states, and in (e), the current supplied from the power source to each of the plurality of electromagnets is adjusted so as to reduce the difference between the identified shape of the substrate and a desired shape of the substrate. [E7] The shape of the substrate processed in (b) is measured; In (e), the currents supplied from the power source to the electromagnets are adjusted so as to reduce a difference between the plasma state acquired by the one or more sensors and a desired plasma state, and to reduce a difference between the measured shape of the substrate and a desired shape of the substrate. The plasma processing method according to any one of embodiments E1 to E4. [E8] the substrate support includes a temperature control mechanism configured to be able to adjust a temperature distribution of the substrate; In the step (e), the temperature control mechanism is controlled to adjust the temperature distribution of the substrate. The plasma processing method according to any one of embodiments E1 to E7. [E9] the gas supply unit is configured to be able to adjust a flow rate distribution of the processing gas supplied to the substrate along a radial direction of the substrate; In the step (e), the gas supply unit is controlled to adjust the distribution of the flow rate of the processing gas along the radial direction of the substrate. The plasma processing method according to any one of embodiments E1 to E8. [E10] a chamber; a substrate support disposed within the chamber; a gas supply configured to supply a process gas into the chamber; a plasma generating unit configured to generate a plasma from the process gas within the chamber; a plurality of electromagnets, each composed of a plurality of coils arranged coaxially with respect to a central axis passing vertically through the center of the substrate support, on a ceiling of the chamber, or a plurality of electromagnets, each having a coil arranged around an axis extending vertically, arranged on the ceiling along a plurality of concentric circles around the central axis and in a radial direction; a power source configured to individually supply current to the plurality of electromagnets; a control unit configured to control the plasma generating unit and a power source; Equipped with The control unit controlling the plasma generating unit to generate a plasma from the process gas in the chamber for processing the substrate; controlling the power supplies to adjust the currents supplied to the plurality of electromagnets based on a plasma state obtained using one or more sensors during the processing of the substrate with the plasma; Plasma processing equipment.

[0087] From the foregoing, it will be understood that various embodiments of the present disclosure have been described herein for purposes of illustration, and that various modifications may be made without departing from the scope and spirit of the present disclosure. Accordingly, the various embodiments disclosed herein are not intended to be limiting, with the true scope and spirit being indicated by the appended claims. [Explanation of symbols]

[0088] 1... plasma processing apparatus, 10... chamber, 16... substrate support, 24... gas supply unit, 26... high frequency power supply, 30... electromagnet, 50... power supply.

Claims

1. a chamber having an interior space; a substrate support disposed within the interior space of the chamber; a gas supply configured to supply a process gas into the interior space of the chamber; a plasma generating unit configured to generate plasma from the processing gas within the interior space of the chamber; a plurality of annular electromagnet units disposed above the internal space of the chamber and coaxial with an axis passing through the internal space, each of the plurality of annular electromagnet units having one or more electromagnets; at least one optical sensor configured to sense a plasma emission intensity distribution in the interior space along a radial direction relative to the axis; at least one power source configured to individually supply current to the plurality of annular electromagnet units; a control unit configured to adjust currents supplied from the at least one power source to each of the plurality of annular electromagnet units based on the emission intensity distribution of the plasma detected by the at least one optical sensor; Equipped with the control unit is configured to adjust the current supplied from the at least one power source to each of the plurality of annular electromagnet units based on a shape of the substrate measured inside or outside the chamber by a shape measuring device. Plasma processing equipment.

2. each of the plurality of annular electromagnet units includes at least one annular electromagnet; The plasma processing apparatus according to claim 1 .

3. The plasma processing apparatus of claim 1 , wherein each of the plurality of annular electromagnet units includes a plurality of electromagnets arranged in a circumferential direction about the axis.

4. The plasma processing apparatus according to claim 3 , wherein each of the plurality of electromagnets includes a bobbin having a cylindrical shape and a coil wound around the bobbin.

5. 5. The plasma processing apparatus according to claim 1, wherein the at least one optical sensor comprises a plurality of optical sensors provided above the internal space and configured to detect the emission intensity distribution.

6. The plasma processing apparatus according to claim 5 , wherein the plurality of optical sensors are arranged along the radial direction.

7. 5. The plasma processing apparatus according to claim 1, wherein the at least one optical sensor is provided along a sidewall of the chamber.

8. The plasma processing apparatus of any one of claims 1 to 7, wherein the control unit is configured to adjust the current supplied to the plurality of annular electromagnet units so as to reduce the difference between the light emission intensity distribution detected by the at least one optical sensor and a desired light emission intensity distribution.

9. 9. The plasma processing apparatus of claim 1, wherein the substrate support includes a temperature control mechanism configured to adjust a temperature distribution of the substrate placed on the substrate support.

10. 10. The plasma processing apparatus of claim 1, wherein the gas supply unit is configured to adjust a radial distribution of a flow rate of the processing gas.

11. A plasma processing method using a plasma processing apparatus, comprising: The plasma processing apparatus includes: a chamber having an interior space; a substrate support disposed within the interior space of the chamber; a gas supply configured to supply a process gas into the interior space of the chamber; a plasma generating unit configured to generate plasma from the processing gas within the interior space of the chamber; a plurality of annular electromagnet units arranged coaxially with respect to an axis passing through the internal space of the chamber above the internal space, each of the plurality of annular electromagnet units having one or more electromagnets; at least one optical sensor configured to sense a plasma emission intensity distribution in the interior space along a radial direction relative to the axis; at least one power source configured to individually supply current to the plurality of annular electromagnet units; The plasma processing method comprises: (a) detecting an emission intensity distribution of the plasma with the at least one optical sensor; (b) adjusting the current supplied from the at least one power source to each of the plurality of annular electromagnet units based on the emission intensity distribution of the plasma; (c) treating a substrate with the plasma generated in the chamber; Including, The shape of the substrate processed in (c) is measured; and (b) adjusting the currents supplied from the at least one power source to each of the plurality of annular electromagnet units so as to reduce a difference between a plasma state based on the emission intensity distribution acquired by the at least one optical sensor and a desired plasma state, and to reduce a difference between the measured shape of the substrate and a desired shape of the substrate. Plasma treatment method.

12. 12. The plasma processing method according to claim 11, wherein in (a), the currents supplied to the plurality of annular electromagnet units are adjusted based on a plasma state that is the emission intensity distribution of the plasma or a distribution of densities or amounts of chemical species in the plasma obtained from the emission intensity distribution.

13. measuring a state of the plasma generated in the chamber using a sensor substrate mounted on the substrate support; adjusting the current supplied from the at least one power source to each of the plurality of annular electromagnet units based on the plasma state measured using the sensor substrate; The plasma processing method according to claim 11 or 12, further comprising:

14. 14. The plasma processing method according to claim 13, wherein the sensor substrate is configured to measure a distribution of a flux of ions or radicals supplied to the sensor substrate as the plasma state.

Images