Monitoring method and plasma processing apparatus

Abstract

The monitoring method of the present invention includes a step of determining a first electric power supplied to heaters of a plurality of partitions provided in a substrate support portion within a chamber. The first electrical power is an electrical power when plasma is generated within the chamber and each of the partitions is controlled to a certain temperature by a heater disposed therein. The monitoring method further includes the step of determining a heat flux from the plasma to each partition. The heat flux from the plasma to each section is obtained by dividing the difference between the first electric power and the second electric power supplied to the heater provided in each section by the area of each section. The second electric power provided to each of the partitions is the electric power provided to the heater when no plasma is generated within the chamber and each of the partitions is controlled to a certain temperature by the heater disposed therein.

Description

Technical Field

[0001] Exemplary embodiments of the present invention relate to a monitoring method and a plasma processing apparatus. Background Art

[0002] A plasma processing device is used to perform plasma processing on a substrate. The plasma processing device includes a chamber and a substrate support. The substrate support is arranged in the chamber to support the substrate placed thereon. The substrate support sometimes includes a plurality of partitioned heaters respectively arranged therein. The temperatures of the plurality of partitions of the substrate support can be adjusted individually by using each heater, and the temperatures of the plurality of regions of the substrate can be adjusted individually. Patent document 1 below discloses such a plasma processing device.

[0003] Prior art literature

[0004] Patent Literature

[0005] Patent Document 1: Japanese Patent Application Publication No. 2016-001688. Summary of the invention

[0006] Technical problem to be solved by the invention

[0007] The present invention provides a technique for monitoring the state of plasma.

[0008] Technical solutions to the problem

[0009] In an exemplary embodiment, a monitoring method is provided. The monitoring method includes: a step of determining a first electric power provided to a heater of each of a plurality of partitions disposed in a substrate support portion of a plasma processing device. The substrate support portion is disposed in a chamber of the plasma processing device. The first electric power is an electric power when plasma is generated in the chamber and each of the plurality of partitions is controlled to a certain temperature by a heater disposed therein. The monitoring method also includes: a step of determining a heat flux from the plasma to each of the plurality of partitions. The heat flux from the plasma to each of the plurality of partitions is obtained by dividing the difference between a second electric power provided to the heater of each of the plurality of partitions and the first electric power by an area of ​​each of the plurality of partitions. The second electric power provided to each of the plurality of partitions is an electric power provided to the heater when plasma is not generated in the chamber and each of the plurality of partitions is controlled to the certain temperature by a heater disposed therein.

[0010] Effects of the Invention

[0011] According to one exemplary embodiment, the state of the plasma can be monitored. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a flow chart of a monitoring method according to an exemplary embodiment.

[0013] Figure 2 FIG. 1 is a diagram schematically showing a plasma processing apparatus according to an exemplary embodiment.

[0014] Figure 3 is an enlarged cross-sectional view of a substrate support portion of a plasma processing apparatus according to an exemplary embodiment.

[0015] Figure 4 FIG. 1 is a diagram showing an example of a layout of a plurality of partitions and a plurality of heaters in a plasma processing apparatus according to an exemplary embodiment.

[0016] Figure 5 FIG. 1 is a diagram showing a system for measuring a self-bias voltage in a plasma processing apparatus according to an exemplary embodiment. DETAILED DESCRIPTION

[0017] Various exemplary embodiments are described below.

[0018] In an exemplary embodiment, a monitoring method is provided. The monitoring method includes: a step of determining a first electric power provided by a heater of each of a plurality of partitions disposed in a substrate support portion of a plasma processing device. The substrate support portion is disposed in a chamber of the plasma processing device. The first electric power is an electric power when plasma is being generated in the chamber and each of the plurality of partitions is controlled to a certain temperature by a heater disposed therein. The monitoring method also includes: a step of determining a heat flux from the plasma to each of the plurality of partitions. The heat flux from the plasma to each of the plurality of partitions is obtained by dividing the difference between a second electric power provided to the heater disposed in each of the plurality of partitions and the first electric power by the area of ​​each of the plurality of partitions. The second electric power provided to each of the plurality of partitions is an electric power provided to the heater when plasma is not generated in the chamber and each of the plurality of partitions is controlled to the certain temperature by a heater disposed therein.

[0019] The difference between the second electric power and the first electric power is equivalent to the heat input from the plasma. The heat flux to each partition can be determined by dividing the heat input from the plasma to each partition by the area of ​​each partition. The heat flux to each partition reflects the density of the plasma above each partition. Therefore, according to the above embodiment, the state of the plasma above each partition can be monitored.

[0020] In an exemplary embodiment, the monitoring method may further include: a step of determining a time-accumulated value of a heat flux or heat input from the plasma to each of the plurality of partitions. The monitoring method may further include: a plasma processing control step of controlling a plasma processing performed using the plasma according to the time-accumulated value of the heat flux or heat input from the plasma to each of the plurality of partitions. In an exemplary embodiment, the plasma processing control step may include: a step of performing other plasma processing in the chamber when the time-accumulated value of the heat flux or heat input reaches a specified value.

[0021] In an exemplary embodiment, the monitoring method may further include: determining the thickness of the plasma sheath above each of the plurality of partitions based on the heat flux from the plasma to each of the plurality of partitions and the self-bias voltage of the substrate support. The monitoring method may further include: determining the traveling direction of ions from the plasma in the space above each of the plurality of partitions based on the thickness of the plasma sheath above each of the plurality of partitions.

[0022] In another exemplary embodiment, a plasma processing device is provided. The plasma processing device includes a chamber, a plasma generating portion, a substrate supporting portion, a heater controller, and a control portion. The plasma generating portion is configured to generate plasma in the chamber. The substrate supporting portion is disposed in the chamber. The substrate supporting portion includes a heater for each of a plurality of partitions disposed therein. The heater controller is configured to provide electric power to the heater for each of a plurality of partitions disposed therein. The control portion determines a first electric power provided from the heater controller to the heater for each of a plurality of partitions when plasma is being generated in the chamber and each of a plurality of partitions is controlled to a certain temperature by the heater disposed therein. The control portion determines a heat flux from the plasma to each of a plurality of partitions by dividing the difference between the second electric power provided to the heater for each of a plurality of partitions and the first electric power by the area of ​​each of a plurality of partitions. The second electric power provided to the heater for each of a plurality of partitions is the electric power provided to the heater for each of a plurality of partitions when plasma is not generated in the chamber and each of a plurality of partitions is controlled to a certain temperature by the heater disposed therein.

[0023] In an exemplary embodiment, the control unit may determine a time-accumulated value of a heat flux or heat input from the plasma to each of the plurality of partitions. The control unit may also control a plasma process using the plasma based on the time-accumulated value of the heat flux or heat input from the plasma to each of the plurality of partitions. In an exemplary embodiment, the control unit may perform other plasma processes in the chamber when the time-accumulated value of the heat flux or heat input reaches a specified value.

[0024] In an exemplary embodiment, the control unit may determine the thickness of the plasma sheath above each of the plurality of partitions based on the heat flux from the plasma to each of the plurality of partitions and the self-bias voltage of the substrate support unit. The control unit may also determine the traveling direction of ions from the plasma in the space above each of the plurality of partitions based on the thickness of the plasma sheath above each of the plurality of partitions.

[0025] Hereinafter, various exemplary embodiments will be described in detail with reference to the accompanying drawings. In addition, in each of the drawings, the same reference numerals are given to the same or corresponding parts.

[0026] Figure 1 is a flow chart of a monitoring method according to an exemplary embodiment. Figure 1 The monitoring method shown (hereinafter referred to as "method MT") is performed using a plasma processing apparatus.

[0027] Figure 2 FIG. 1 is a diagram schematically showing a plasma processing apparatus according to an exemplary embodiment. Figure 2 The plasma processing apparatus 1 shown 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 .

[0028] The chamber 10 has a substantially cylindrical shape in which an internal space 10s is provided. Figure 2 The axis AX shown is the central axis of the chamber 10 and the internal space 10s, and extends in the vertical direction. In the following description, "radial direction" and "circumferential direction" are directions based on the axis AX.

[0029] The chamber 10 may also include a chamber body 12. The chamber body 12 has a substantially cylindrical shape. The chamber body 12 is formed of a metal such as aluminum and is grounded. An internal space 10s is provided inside the chamber body 12. The internal space 10s can be decompressed by an exhaust device 14.

[0030] The side wall of the chamber 10 is provided with a passage 10 p. When the substrate W is transported between the inside and the outside of the chamber 10, it passes through the passage 10 p. The passage 10 p is opened and closed by a gate valve 10 g. The gate valve 10 g is provided along the side wall of the chamber 10.

[0031] The plasma processing apparatus 1 further includes a substrate support portion 16. The substrate support portion 16 is provided in the chamber 10. The substrate support portion 16 is configured to be able to support the substrate W placed thereon. The central axis of the substrate support portion 16 coincides with the axis AX.

[0032] The following, with Figure 2 Refer to Figure 3 . Figure 3 1 is an enlarged cross-sectional view of a substrate support portion of a plasma processing apparatus according to an exemplary embodiment. In one embodiment, the substrate support portion 16 may include a pedestal 18 and an electrostatic chuck 20. The pedestal 18 is formed of a conductive material such as aluminum and has a substantially disc shape. The pedestal 18 may also provide a flow path 18f therein. A refrigerant is supplied from the cooling unit CU to the flow path 18f. The refrigerant supplied from the cooling unit CU flows through the flow path 18f and returns to the cooling unit CU.

[0033] The electrostatic chuck 20 is disposed on the base 18. Figure 3 As shown, the substrate W is placed on the electrostatic chuck 20 in such a manner that its center is located on the axis AX. In addition, the substrate W can have a diameter of, for example, 300 mm. The substrate support portion 16 can also be configured to support the edge ring ER placed thereon. The substrate W is arranged on the electrostatic chuck 20 and in a region surrounded by the edge ring ER.

[0034] The electrostatic chuck 20 includes a dielectric portion 20d, an electrode 201, and an electrode 202. The dielectric portion 20d is formed of a dielectric such as aluminum nitride or aluminum oxide. The dielectric portion 20d has a substantially disk shape. The dielectric portion 20d includes a substrate mounting region and an edge ring mounting region. The substrate mounting region is a region on which a substrate W is mounted. The edge ring mounting region is a region on which an edge ring ER is mounted. The edge ring mounting region extends in a circumferential direction in a manner surrounding the substrate mounting region.

[0035] The electrode 201 is a conductive film and is provided in the substrate mounting region of the dielectric portion 20d. The power supply 601 is electrically connected to the electrode 201. When a DC voltage from the power supply 601 is applied to the electrode 201, an electrostatic attraction is generated between the electrostatic chuck 20 and the substrate W. The generated electrostatic attraction causes the substrate W to be attracted to the electrostatic chuck 20 and held by the electrostatic chuck 20.

[0036] The electrode 202 is a conductive film, and is provided in the edge ring mounting region of the dielectric portion 20d. The power supply 602 is electrically connected to the electrode 202. When a DC voltage from the power supply 602 is applied to the electrode 202, an electrostatic attraction is generated between the electrostatic chuck 20 and the edge ring ER. The edge ring ER is attracted to the electrostatic chuck 20 by the generated electrostatic attraction, and is held by the electrostatic chuck 20. In addition, the electrode 202 may be a bipolar electrode constituting a bipolar electrostatic chuck.

[0037] The substrate support portion 16 includes a plurality of partitions 20Z. Figure 2 and Figure 3 Refer to Figure 4 . Figure 4 1 is a diagram showing an example of the layout of multiple zones and multiple heaters in a plasma processing apparatus according to an exemplary embodiment. In one embodiment, multiple zones 20Z are provided in the electrostatic chuck 20. The multiple zones 20Z are distributed on a plane orthogonal to the axis AX. Figure 4 As shown, one or more partitions 20Z may be provided in each of the plurality of coaxial regions within the electrostatic chuck 20. In addition, the partition 20Z located at the outermost side (in the outermost annular region) in the radial direction is located below the edge ring ER. Figure 4 In the example, the number of the partitions 20Z in the outermost annular region is one. However, a plurality of partitions may be provided in the outermost annular region. In the outermost annular region, the plurality of partitions are arranged in the circumferential direction.

[0038] The substrate support portion 16 further includes a plurality of heaters HT. The plurality of heaters HT are respectively provided in the plurality of partitions 20Z. Each of the plurality of heaters HT is, for example, a resistance heating element. The plurality of heaters HT receive electric power (electricity) individually supplied from the heater controller HC to generate heat.

[0039] The substrate support 16 further includes a plurality of temperature sensors TS and a temperature measuring device TD. The plurality of temperature sensors TS outputs sensor values ​​reflecting the temperature of each of the plurality of sub-zones 20Z to the temperature measuring device TD. The temperature measuring device TD determines the temperature measurement value of each of the plurality of sub-zones 20Z based on the sensor values ​​of each of the plurality of sub-zones 20Z. The heater controller HC individually controls the electric power supplied to each of the plurality of sub-zones 20Z based on the temperature measurement value of each of the plurality of sub-zones 20Z to adjust the temperature of each of the plurality of sub-zones 20Z to a certain temperature.

[0040] like Figure 2As shown, the plasma processing apparatus 1 further includes an upper electrode 22. The upper electrode 22 is disposed above the substrate support portion 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 (pores) 22h. In addition, the number of gas diffusion chambers may be any number greater than two.

[0041] The plurality of gas diffusion chambers 22a to 22c are separated from each other and are coaxially arranged in the upper electrode 22. The central axis of the plurality of gas diffusion chambers 22a to 22c is the axis AX. The gas diffusion chamber 22a is circular when viewed from above and is a space intersecting the axis AX. The gas diffusion chambers 22b to 22c are respectively substantially annular spaces. The gas diffusion chamber 22b is radially arranged outside the gas diffusion chamber 22a. The gas diffusion chamber 22c is radially arranged outside the gas diffusion chamber 22b. The plurality of gas holes 22h extend downward from the corresponding gas diffusion chambers in the plurality of gas diffusion chambers 22a to 22c, respectively, and open toward the internal space 10s.

[0042] 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 adjust the distribution of the flow rate 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 above-mentioned shower head, and is configured to supply the processing gas separately to each of the plurality of gas diffusion chambers 22a to 22c.

[0043] The gas supply unit 24 may further include a gas source group 24a, a flow controller group 24b, a valve group 24c and a diverter 24d. The gas source group 24a includes one or more gas sources. Gases from one or more gas sources constitute the processing gas. The flow controller group 24b includes one or more flow controllers. The valve group 24c includes one or more opening and closing valves. The one or more gas sources of the gas source group 24a are each connected to the diverter 24d via a corresponding flow controller of the flow controller group 24b and a corresponding opening and closing valve of the valve group 24c. The diverter 24d is configured to distribute the supplied processing gas to a plurality of gas diffusion chambers 22a to 22c. The diverter 24d can adjust the distribution ratio of the processing gas to the plurality of gas diffusion chambers 22a to 22c.

[0044] In the plasma processing apparatus 1, the processing gas supplied to the gas diffusion chamber 22a is supplied to the central area of ​​the substrate W from the multiple gas holes 22h connected to the gas diffusion chamber 22a. The processing gas supplied to the gas diffusion chamber 22b is supplied to the edge area of ​​the substrate W from the multiple gas holes 22h connected to the gas diffusion chamber 22b. The processing gas supplied to the gas diffusion chamber 22c is supplied to the area radially outward of the edge of the substrate W from the multiple gas holes 22h connected to the gas diffusion chamber 22c. The gas supply unit 24 can adjust the distribution of the flow rate of the processing gas along the radial direction of the substrate W by adjusting the distribution ratio of the processing gas to the multiple gas diffusion chambers 22a to 22c using the diverter 24d.

[0045] The plasma processing device 1 also includes a high-frequency power supply 26. The high-frequency power supply 26 constitutes a plasma generating unit of one embodiment. The high-frequency power supply 26 is connected to the high-frequency electrode via a matching device 26m. The high-frequency power supply 26 generates a generating source high-frequency electric power supplied to the high-frequency electrode. The high-frequency electrode may also be an electrode in the substrate support portion 16. In one embodiment, the high-frequency electrode may also be a base 18. The generating source high-frequency electric power has a frequency suitable for generating plasma. The matching device 26m has a matching circuit for matching the impedance of the load of the high-frequency power supply 26 with the output impedance of the high-frequency power supply 26. In addition, the high-frequency power supply 26 may also be connected to the upper electrode 22. That is, the upper electrode 22 may also be a high-frequency electrode.

[0046] The plasma processing device 1 may further include a bias power supply 28. The bias power supply 28 is electrically connected to the bias electrode of the substrate support portion 16. The bias power supply 28 generates an electrical bias supplied to the bias electrode. In order to introduce ions into the substrate W, the electrical bias is supplied to the bias electrode of the substrate support portion 16. In one embodiment, the bias electrode may be a base 18. The electrical bias generated by the bias power supply 28 may be a bias high-frequency electric power. In the case where the electrical bias is a bias high-frequency electric power, the bias power supply 28 is connected to the bias electrode via a matcher 28m. The matcher 28m has a matching circuit for matching the impedance of the load of the bias power supply 28 with the output impedance of the bias power supply 28. Alternatively, the electrical bias generated by the bias power supply 28 may also be a pulse of voltage generated intermittently or periodically. In the case where the electrical bias is a pulse of voltage, the plasma processing device 1 does not include the matcher 28m.

[0047] In the plasma processing device 1, the processing gas is supplied from the gas supply unit 24 into the chamber 10. In addition, the pressure in the chamber 10 is reduced by the exhaust device 14. In addition, the high-frequency electric power of the generation source is supplied from the high-frequency power supply 26 to the high-frequency electrode. As a result, plasma can be generated from the processing gas in the chamber 10. The substrate W is processed by chemical species such as free radicals and ions from the plasma. For example, the film of the substrate W is etched. The energy of the ions supplied to the substrate W can be adjusted by the electrical bias from the bias power supply 28.

[0048] like Figure 2 As shown, the plasma processing device 1 may further include a plurality of electromagnets 30. The plurality of electromagnets 30 are disposed on or inside the top (upper electrode 22) of the chamber 10. The plurality of electromagnets 30 include electromagnets 31 to 3N. Each of the plurality of electromagnets 30 is composed of a coil wound around the axis AX. The plurality of electromagnets 30 have different inner diameters and are coaxially disposed. Several of the plurality of electromagnets 30 are disposed above the substrate W. One or more of the plurality of electromagnets 30 may also be disposed above an area outside the edge of the substrate W.

[0049] The plasma processing device 1 may further include a bobbin component 40. The bobbin component 40 may be formed of a magnetic material. The bobbin component 40 includes bobbins 41 to 4N. The coils of the electromagnets 31 to 3N are respectively wound around the bobbins 41 to 4N. The bobbins 41 to 4N are arranged coaxially, and their central axes are the axis AX. The bobbin 41 is cylindrical. The bobbins 42 to 4N have a cylindrical shape and are arranged radially outside the bobbin 41. The bobbin component 40 may further include a cylindrical portion 40e and a base 40b. The cylindrical portion 40e is arranged concentrically with the bobbins 41 to 4N, and surrounds the electromagnet 3N radially outside the bobbin 4N. The base 40b has a substantially disc shape. The bobbins 41 to 4N and the cylindrical portion 40e are formed integrally with the base 40b, and extend downward from the base 40b.

[0050] The plasma processing apparatus 1 further includes a power supply 50. The power supply 50 is configured to be able to supply current to the coils of the plurality of electromagnets 30 individually. The current supplied from the power supply 50 to the coils of the plurality of electromagnets 30 is, for example, a direct current. The current supplied to the coils of the plurality of electromagnets 30 by the power supply 50 is individually controlled by a control unit Cnt described later.

[0051] The plurality of electromagnets 30 form magnetic fields that are symmetrical about the axis AX in the chamber 10. In addition, a composite magnetic field is formed in the chamber 10 by the magnetic fields formed by the plurality of electromagnets 30. The composite magnetic field is also symmetrical about the axis AX. In addition, by controlling the currents supplied to the plurality of electromagnets 30, the distribution of the magnetic field intensity in the radial direction relative to the axis AX can be adjusted. Thus, the plasma processing device 1 can adjust the distribution of the density of the plasma in the chamber 10 in the radial direction of the substrate W.

[0052] In one embodiment, the plasma processing apparatus 1 may further include a first measurement system and a second measurement system. The first measurement system is configured to measure a self-bias voltage V dcW , including a relay box 621 and a measuring device 641. The second measuring system is configured to measure the self-bias voltage V dcE , including a relay box 622 and a measuring device 642. In addition, the relay box 621 can also be a part of the measuring device 641. In addition, the relay box 622 can also be a part of the measuring device 642.

[0053] Below, refer to Figure 5 . Figure 5 FIG. 1 is a diagram showing a system for measuring a self-bias voltage in a plasma processing apparatus according to an exemplary embodiment. Figure 5 The relay boxes 62 shown are used as relay boxes 621 and relay boxes 622. Figure 5 The measuring devices 64 shown are used as a measuring device 641 and a measuring device 642 .

[0054] The measuring device 64 includes a filter 64f, a component with electrostatic capacitance, a probe 64p and a potential measuring device 64m. The filter 64f is a filter that cuts off high-frequency electric power. In one example, the component with electrostatic capacitance has a structure in which an acrylic plate 64a is sandwiched between a copper disc 64c and a copper plate 64d. The copper disc 64c is connected to an electrode (electrode 201 or 202) via the filter 64f and the relay box 62. The copper plate 64d is grounded. The potential measuring device 64m is configured to be able to measure the potential of the copper disc 64c using a probe 64p that is arranged on the surface of the copper disc 64c in a non-contact manner.

[0055] The relay box 621 switches the connection of the electrode 201 between the power supply 601 and the component having electrostatic capacitance of the measuring device 641. The power supply 601 is connected to the electrode 201 via the switch 62s of the relay box 621. When the switch 62s of the relay box 621 is closed, the voltage from the power supply 601 is applied to the electrode 201. When the switch 62s of the relay box 621 is open, the potentiometer 64m of the measuring device 641 measures the floating voltage V generated in the component having electrostatic capacitance of the measuring device 641. 21 .

[0056] The relay box 622 switches the connection of the electrode 202 between the power supply 602 and the component having electrostatic capacitance of the measuring device 642. The power supply 602 is connected to the electrode 202 via the switch 62s of the relay box 622. When the switch 62s of the relay box 622 is closed, the voltage from the power supply 602 is applied to the electrode 202. When the switch 62s of the relay box 622 is open, the potentiometer 64m of the measuring device 642 measures the floating voltage V generated in the component having electrostatic capacitance of the measuring device 642. 22 .

[0057] The control unit Cnt determines the self-bias voltage V of the substrate W using the following equation (1): dcW .

[0058] [Number 1]

[0059] V dcW =V 21 ×(C2+C3) / C 11 +V 21 (1)

[0060] In addition, the control unit Cnt determines the self-bias voltage V of the edge ring ER using the following equation (2): dcE .

[0061] [Number 2]

[0062] V dcE =V 22 ×(C2+C3) / C 12 +V 22 (2)

[0063] C 11 is the electrostatic capacitance of the substrate mounting area of ​​the electrostatic chuck 20, C 12 is the electrostatic capacitance of the edge ring mounting region of the electrostatic chuck 20. C2 is the electrostatic capacitance determined by the structure of the copper disk 64c, the copper plate 64d, and the acrylic plate 64a. C3 is the electrostatic capacitance determined by the structure of the filter 64f.

[0064] The plasma processing device 1 further includes a control unit Cnt. The control unit Cnt is a computer including a processor, a storage device, an input device, a display device, etc., and controls the various parts of the plasma processing device 1. Specifically, the control unit Cnt executes a control program stored in the storage device, and controls the various parts of the plasma processing device 1 based on the processing scheme data stored in the storage device. Through the control of the control unit Cnt, the process specified by the processing scheme data is executed in the plasma processing device 1. In addition, the method MT can be performed by the control of the control unit Cnt on the various parts of the plasma processing device 1.

[0065] Refer again Figure 1 , method MT is described. Method MT includes steps STa to STc and STp. In step STa, plasma is generated in the chamber 10. In step STa, the control unit Cnt controls the gas supply unit 24 to supply the processing gas into the chamber 10. In addition, in step STa, the control unit Cnt controls the exhaust device 14 to set the pressure in the chamber 10 to a specified pressure. In addition, in step STa, the control unit Cnt controls the plasma generation unit to generate plasma from the processing gas in the chamber. In one embodiment, the control unit Cnt controls the high-frequency power supply 26 to supply high-frequency electric power to the generation source. In addition, in step STa, the heater controller HC individually controls the electric power (electricity) supplied to the multiple heaters HT respectively to adjust the temperature of each of the multiple partitions 20Z to a certain temperature T specified by the control unit Cnt. C The heater controller HC individually controls the electric power supplied to each of the plurality of heaters HT according to the temperature of each of the plurality of partitions 20Z measured by the temperature measuring device TD.

[0066] In step STb, the first electric power P supplied from the heater controller HC to the heater HT provided in each of the plurality of zones 20Z is determined. ON That is, the first electric power P supplied from the heater controller to the heater HT[i] provided in the zone 20Z[i] is determined. ON [i] Here, "i" is the index of each of the plurality of partitions 20Z. The first electric power P ON [i] can be determined by the control unit Cnt. The first electric power P ON [i] is the plasma generated in step STa and the zone 20Z[i] is controlled to a certain temperature T by the heater HT[i] c The electric power provided to the heater HT[i] at the time. The first electric power P ON [i] can be determined by calculating the following formula (3).

[0067] [Number 3]

[0068] P ON [i] = V ON [i] 2 / R[i]×D[i]×c[i] (3)

[0069] In formula (3), V ON [i] is the average value of the AC voltage applied from the heater controller HC to the heater HT[i]. In formula (3), R[i] is the resistance value of the heater HT[i]. In formula (3), D[i] is the value of the ratio of the electric power supplied from the heater controller HC to the heater HT[i] in step STa to the maximum electric power that can be supplied from the heater controller HC to the heater HT[i]. In addition, in formula (3), c[i] is a predetermined coefficient for the partition 20Z[i].

[0070] In step STc, a heat flux (heat flow) Γ from the plasma generated in step STa to each of the plurality of sub-zones 20Z is determined. That is, a heat flux Γ[i] from the plasma generated in step STa to the sub-zone 20Z[i] is determined. The heat flux F[i] can be determined by the control unit Cnt. Γ[i] is determined by the calculation of the following formula (4).

[0071] [Number 4]

[0072] Γ[i]=(P OFF [i]-P ON [i]) / a[i] (4)

[0073] In equation (4), the heat flux Γ[i] can be obtained by the second electrical power P OFF [i] and the first electric power P ON The second electric power P is obtained by dividing the heat input J[i] by the area a[i] of the partition 20Z[i]. OFF [i] means that no plasma is generated in the chamber 10 and the zone 20Z[i] is controlled to a constant temperature T by the heater HT[i]. c The electric power supplied from the heater controller HC to the heater HT[i] when OFF [i] Determined by the control unit Cnt in step STp. Step STp can be performed at any time as long as it is before step STc. The second electric power P OFF [i] can also be determined by the same formula as the right side of formula (3).

[0074] The second electric power P OFF [i] and the first electric power P ONThe difference between the values ​​of area a[i] and area b[i] is equivalent to the heat input J[i] from the plasma. By dividing the heat input J[i] from the plasma to the partition 20Z[i] by the area a[i] of the partition 20Z[i], the heat flux Γ[i] to the partition 20Z[i] can be determined. The heat flux Γ[i] to the partition 20Z[i] reflects the density of the plasma above the partition 20Z[i]. Therefore, according to method MT, the state of the plasma above each of the multiple partitions 20Z can be monitored.

[0075] like Figure 1 As shown, the method MT may further include a step STd. In the step STd, at least one of the plurality of applications is executed. The following describes each application separately.

[0076] [First Application]

[0077] In the first application, step STd includes determining a time-accumulated value of a heat flux or heat input from the plasma to each of the plurality of zones 20Z. That is, in step STd, the control unit Cnt determines a time-accumulated value A[i] of a heat flux Γ[i] or a heat input J[i] from the plasma to the zone 20Z[i]. In addition, step STd also includes controlling the plasma treatment according to the time-accumulated value A[i]. The plasma treatment is controlled by the control unit Cnt. In one embodiment, when the time-accumulated value A[i] reaches a predetermined value in the state where the plasma treatment is performed in step STa, other plasma treatments are performed in the chamber 10.

[0078] In one example, the first application is performed for plasma etching of a multilayer film of a substrate W. When the time integrated value A[i] reaches a predetermined value while plasma etching of the first layer of the multilayer film is being performed, plasma etching of the second layer of the multilayer film is performed. The processing gas used in the plasma etching of the first layer is different from the processing gas used in the plasma etching of the second layer. The first layer may be a silicon oxide film, and the second layer may be a silicon nitride film. The multilayer film of the substrate W may also include a plurality of first layers and a plurality of second layers alternately stacked.

[0079] [Second application]

[0080] In the second application, step STd includes determining the thickness of the plasma sheath above each of the plurality of sub-areas 20Z based on the heat flux from the plasma to each of the plurality of sub-areas 20Z and the self-bias voltage of the substrate support 16. That is, in step STd, based on the heat flux Γ[i] and the self-bias voltage V dc [i], determine the thickness T of the plasma sheath above the partition 20Z[i] PS [i] Thickness T PS[i] can be determined by the control unit Cnt using the following formula (5).

[0081] [Number 5]

[0082] T PS [i] = p × 4.502 × 10 3 ×(2V dc [i]) 3 / 4 / (T e 1 / 4 ×(n e [i]) 1 / 2 ) (5)

[0083] In formula (5), p is a predetermined coefficient, T e is the predetermined electron temperature, n e [i] is the electron density determined by the following equation (6). In equations (5) and (6), for the subarea 20Z[i] below the substrate W, the self-bias voltage V dc [i] is the above V dcW In addition, regarding the subarea 20Z[i] below the edge ring ER, the self-bias voltage V dc [i] is the above V dcE .

[0084] [Number 6]

[0085] n e[i] =q×Γ[i] / (V dc [i]) 1 / 2 (6)

[0086] In addition, in the formula (6), q is a coefficient determined in advance.

[0087] In the second application, step STd further includes the step of determining the traveling direction of ions from the plasma in the space above the plurality of partitions 20Z based on the thickness of the plasma sheath above each of the plurality of partitions 20Z. Specifically, the traveling direction of ions in the space above the partition 20Z[i], that is, the angle θ[i] formed by the traveling direction of the ions with respect to the vertical direction, can be obtained by the control unit Cnt using the following formula (7).

[0088] [Number 7]

[0089] θ[i]=x×arctan(|T PS [i n ]-T PS [i]| / y) (7)

[0090] In formula (7), x and y are coefficients determined in advance. PS [i n] is a partition 20Z[i] radially inside the partition 20Z[i] among the plurality of partitions 20Z and is an adjacent partition 20Z[i] of the partition 20Z[i]. n ] is the thickness of the plasma sheath above. In addition, y can be the distance between the center of the partition 20Z[i] and the partition 20Z[i-1] on the same radius centered on the axis AX.

[0091] In the second application, step STd may also include controlling the regulator 70 (see Figure 3 ) to correct the traveling direction of ions relative to the edge of the substrate W to a vertical direction. The regulator 70 is controlled by the control unit Cnt. The regulator 70 may also adjust the voltage applied to the edge ring ER to correct the traveling direction of ions to a vertical direction. Alternatively, the regulator 70 may also change the position of the edge ring ER in the vertical direction to correct the traveling direction of ions to a vertical direction.

[0092] In step STd of the second application, the partition 20Z[i OM ](first partition) sheath thickness T PS [i OM ], and in partition 20Z[i OM ] and partition 20Z[i OM ] Adjacent partition 20Z[i NB ](Second partition) sheath thickness T PS [i NB Furthermore, in step STd, the controller Cnt may control the regulator 70 so that the thickness T PS [i OM ] and thickness T PS [i NB The regulator 70 can also adjust the voltage applied to the edge ring ER or change the vertical position of the edge ring ER so that the thickness T PS [i OM ] and thickness T PS [i NB ] is substantially the same. More preferably, the height position of the upper end of the sheath above the substrate W and the height position of the upper end of the sheath above the edge ring ER can also be obtained. The height position of the upper end of the sheath above the substrate W can be obtained by adding the thickness of the substrate W and the thickness T to the height position of the upper surface of the substrate mounting area. PS [i NB The height position of the upper end of the sheath above the edge ring ER can be obtained by adding the thickness of the edge ring ER and the thickness T to the height position of the upper surface of the edge ring mounting area. PS [i OM] can be obtained. In addition, the absolute value of the difference between the height direction position of the upper end of the sheath above the substrate W and the height direction position of the upper end of the sheath above the edge ring ER can also be obtained. Alternatively, when the absolute value exceeds a predetermined threshold value, the regulator 70 adjusts the voltage applied to the edge ring ER or changes the vertical position of the edge ring ER so that the height direction position of the upper end of the sheath above the substrate W is substantially the same as the height direction position of the upper end of the sheath above the edge ring ER. In addition, the thickness T PS [i NB ] can also be calculated as the outermost partition 20Z[i OM ]A plurality of adjacent and circumferentially arranged partitions 20Z[i NB ] The thickness of the edge ring ER can also be measured using another measuring device. Alternatively, the thickness of the edge ring ER can also be obtained by the control unit Cnt based on the cumulative time of the plasma treatment by referring to the database.

[0093] [Third Application]

[0094] In the third application, step STd can also reduce the deviation of the heat flux Γ to each of the multiple partitions 20Z determined in step STc. The deviation of the heat flux Γ to each of the multiple partitions 20Z can also be reduced by at least one of the first to third processes. The first process individually adjusts the current supplied from the power supply 50 to the multiple electromagnets 30 respectively. The second process adjusts the distribution of the flow rate of the processing gas along the radial direction of the substrate W through the diverter 24d. The third process uses multiple heaters HT to individually adjust the temperature of the multiple partitions 20Z. In the third application, the power supply 50, the diverter 24d and the heater controller HC are controlled by the control unit Cnt. According to the third application, the density distribution of the plasma is uniformized. Alternatively (or also on this basis), according to the third application, the in-plane uniformity of the plasma treatment (such as plasma etching) performed on the substrate W can be improved.

[0095] [Fourth Application]

[0096] In the fourth application, step STd includes the step of monitoring the temporal change of the heat flux Γ to each of the plurality of zones 20Z determined in step STc. Step STd including the step of monitoring the temporal change of the heat flux Γ can be performed by the control unit Cnt.

[0097] In one example of step STd of the fourth application, by monitoring the daily temporal change of the heat flux Γ to each of the plurality of zones 20Z determined in step STc, it is possible to determine whether the plasma processing apparatus 1 is being stably operated.

[0098] In another example of step STd of the fourth application, the seasoning process may be started after the parts in the chamber 10 are replaced, and the seasoning process may be terminated when the criterion for judging that the heat flux Γ to each of the plurality of partitions 20Z is stable is satisfied. In addition, when the impedance of the chamber 10 changes due to the opening of the chamber 10 to the atmosphere compared with before the opening of the chamber 10 to the atmosphere, the ion energy of the substrate incident on the substrate support 16 changes. The change in the impedance of the chamber 10 occurs due to the following circumstances: when the chamber 10 is opened for replacing parts, moisture is adsorbed on the surface in the chamber 10, the replacement parts are arranged in the chamber 10, and the deposits attached to the parts in the chamber 10 and / or the surfaces in the chamber 10 are in contact with the atmosphere, so that their composition changes. By performing the seasoning process after the chamber 10 is evacuated, the impedance of the chamber 10 converges to a certain value, and the ion energy incident on the substrate also converges to a certain value. Therefore, the aging treatment can be terminated when the heat flux Γ at the end of the aging treatment reaches a certain value. Therefore, the heat flux Γ to at least one of the multiple partitions 20Z can be monitored, and the heat flux Γ to two or more or all of the multiple partitions 20Z can also be monitored. In the case of monitoring the heat flux Γ to two or more or all of the partitions 20Z, the time when the heat flux Γ is stable can also be used as the end point of the aging treatment. Alternatively, the time when the heat flux Γ to specific partitions of the multiple partitions 20Z is stable can also be used as the end point of the aging treatment.

[0099] In another example of step STd of the fourth application, by monitoring the temporal change of the heater output for each of the plurality of zones 20Z, it is possible to detect the abnormality in the attraction of the substrate W by the electrostatic chuck 20. In addition, when the abnormality in the attraction of the substrate W by the electrostatic chuck 20 occurs, the electrostatic chuck 20 does not normally attract the substrate W, or the attraction force of the electrostatic chuck 20 to the substrate W is weak. When the abnormality in the attraction of the substrate W by the electrostatic chuck 20 occurs, the heat from the plasma does not normally flow to the electrostatic chuck 20 through the substrate W. Therefore, when the abnormality in the attraction of the substrate W by the electrostatic chuck 20 occurs, the heater output (electric power output by the heater controller) in the plasma processing is higher than the heater output when the attraction of the substrate W by the electrostatic chuck 20 is normal. By temporally monitoring the heater output during the plasma processing of one substrate W and / or temporally monitoring the heater output every time the substrate W is subjected to the plasma processing, the time when the abnormality in the attraction of the substrate W occurs can be determined, and the substrate W subjected to the plasma processing in the state where the abnormality in the attraction occurs can be determined. In this example, the heater output of at least one of the plurality of zones 20Z may be monitored, or the heater output of two or more or all of the plurality of zones 20Z may be monitored. By monitoring the heater output of the plurality of zones 20Z, it is also possible to identify an adsorption abnormality region in the electrostatic chuck 20. In addition, it is possible to detect not only an adsorption abnormality of the electrostatic chuck 20 to the substrate W, but also an adsorption abnormality of the electrostatic chuck 20 to the edge ring ER.

[0100] In still another example of step STd of the fourth application, by monitoring the temporal change of the heat flux Γ to each of the plurality of partitions 20Z, the end time of the plasma processing on the substrate W can be detected.

[0101] [Fifth Application]

[0102] In the fifth application, step STd comprises monitoring the electron density n e [i] Step. Including electron density n e The monitoring step STd of [i] can be performed by the control unit Cnt. e [i] It is possible to detect the consumption of components in the chamber 10, such as the upper electrode 22.

[0103] [Sixth Application]

[0104] In the sixth application, step STd includes the step of monitoring the electric power supplied from the heater controller HC to the heater HT in the subzone 20Z below the edge ring ER. The monitoring of the electric power in step STd can be performed by the control section Cnt. As the thickness of the edge ring ER decreases, the electric power supplied from the heater controller HC to the heater HT in the subzone 20Z below the edge ring ER decreases. Therefore, by monitoring the electric power supplied from the heater controller HC to the heater HT in the subzone 20Z below the edge ring ER, the decrease in the thickness of the edge ring ER can be detected.

[0105] Although a plurality of exemplary embodiments have been described above, the present invention is not limited to the exemplary embodiments described above, and various additions, omissions, substitutions, and changes may be made. In addition, elements in different embodiments may be combined to form other embodiments.

[0106] In other embodiments, the plasma processing apparatus may be another type of plasma processing apparatus such as an inductively coupled plasma processing apparatus, an ECR (electron cyclotron resonance) plasma processing apparatus, or a plasma processing apparatus that generates plasma using surface waves such as microwaves.

[0107] It can be understood from the above description that multiple embodiments of the present invention are described in this specification for the purpose of illustration, and various changes can be made without departing from the scope and spirit of the present invention. Therefore, the various embodiments recorded in this specification are not intended to limit the present invention, and the true scope and spirit are represented by the claims.

[0108] Description of Reference Numerals

[0109] 1 ... plasma processing device, 10 ... chamber, 16 ... substrate supporting portion, 20Z ... partition, HT ... heater, HC ... heater controller, Cnt ... control portion.

Claims

1. A monitoring method, characterized in that: include: A step of determining a first electric power supplied to a heater of each of a plurality of partitions provided in a substrate supporting portion of a plasma processing apparatus, the substrate supporting portion being provided in a chamber of the plasma processing apparatus, the first electric power being an electric power when plasma is being generated in the chamber and each of the plurality of partitions is controlled to a certain temperature by the heater provided therein; and the step of determining a heat flux from the plasma to each of the plurality of zones, The heat flux from the plasma to each of the plurality of partitions is obtained by dividing the difference between the second electric power provided to the heater provided in each of the plurality of partitions and the first electric power by the area of ​​each of the plurality of partitions, The second electric power supplied to the heater provided in each of the plurality of partitions is electric power supplied to the heater when no plasma is generated in the chamber and each of the plurality of partitions is controlled to the constant temperature by the heater provided therein.

2. The monitoring method according to claim 1, characterized in that: Also includes: The step of determining a time-integrated value of said heat flux or heat input from said plasma to each of said plurality of zones; and A plasma processing control step of controlling a plasma processing using the plasma based on the time-accumulated value of the heat flux or the heat input amount from the plasma to each of the plurality of partitions.

3. The monitoring method according to claim 2, characterized in that: The plasma processing control step includes a step of performing another plasma processing in the chamber when the time integrated value of the heat flux or the heat input reaches a predetermined value.

4. The monitoring method according to claim 1, characterized in that: Also includes: A plasma sheath thickness determining step of determining a thickness of a plasma sheath over each of the plurality of subareas based on the heat flux from the plasma to each of the plurality of subareas and a self-bias voltage of the substrate support.

5. The monitoring method according to claim 4, characterized in that: The plurality of partitions include: at least one first partition located below the edge ring; and at least one second partition located inside the at least one first partition and adjacent to the at least one first partition. The plasma sheath thickness determination step includes the steps of determining the thickness of the plasma sheath above the edge ring and the thickness of the plasma sheath above the at least one second partition.

6. The monitoring method according to claim 4, characterized in that: The plurality of partitions include: at least one first partition located below the edge ring and at least one second partition located below the substrate, The monitoring method includes: A step of obtaining a height direction position of an upper end of the plasma sheath above the edge ring according to a thickness of the plasma sheath above the at least one first partition; and The step of obtaining a height direction position of an upper end of the plasma sheath above the substrate according to the thickness of the plasma sheath above the at least one second partition.

7. The monitoring method according to claim 5, characterized in that: Also includes: a regulator controlling step of controlling a regulator so that the thickness of the plasma sheath above the at least one first partition and the thickness of the plasma sheath above the at least one first partition are substantially the same as each other, In the regulator control step, the regulator is controlled to adjust a voltage applied to the edge ring or to change a position of the edge ring in a vertical direction.

8. The monitoring method according to claim 6, characterized in that: Also includes: a regulator control step of controlling the regulator so that the height direction position of the upper end of the plasma sheath above the at least one first partition and the height direction position of the upper end of the plasma sheath above the at least one first partition are substantially the same as each other, In the regulator control step, the regulator is controlled to adjust a voltage applied to the edge ring or to change a position of the edge ring in a vertical direction.

9. The monitoring method according to claim 4, characterized in that: Also includes: The step of determining a traveling direction of ions from the plasma in a space above each of the plurality of partitions based on a thickness of the plasma sheath above each of the plurality of partitions.

10. A plasma processing device, characterized in that: include: Chamber; a plasma generating unit configured to generate plasma in the chamber; a substrate support portion disposed in the chamber, comprising a heater disposed in each of a plurality of partitions of the substrate support portion; a heater controller configured to supply electric power to the heaters provided in each of the plurality of zones; and Control Department, The control unit is configured as follows: It is possible to determine that when plasma is being generated in the chamber and each of the plurality of partitions is controlled to a certain temperature by the heater disposed therein, a first electric power is supplied from the heater controller to the heater disposed in each of the plurality of partitions, determining a heat flux from the plasma to each of the plurality of partitions by dividing a difference between a second electric power supplied to the heater provided in each of the plurality of partitions and the first electric power by an area of ​​each of the plurality of partitions, The second electric power supplied to the heater provided in each of the plurality of partitions is the electric power supplied to the heater when no plasma is generated in the chamber and each of the plurality of partitions is controlled to the constant temperature by the heater provided therein.

11. The plasma processing device according to claim 10, characterized in that: The control unit is further configured as follows: capable of determining a time-integrated value of the heat flux or heat input from the plasma to each of the plurality of partitions, A plasma process using the plasma is controlled based on the time-accumulated value of the heat flux or the heat input amount from the plasma to each of the plurality of partitions.

12. The plasma processing device according to claim 11, characterized in that: The control unit is further configured to perform another plasma process in the chamber when the time integrated value of the heat flux or the heat input reaches a predetermined value.

13. The plasma processing device according to claim 10, characterized in that: The control unit is further configured to determine a thickness of a plasma sheath above each of the plurality of sections based on the heat flux from the plasma to each of the plurality of sections and a self-bias voltage of the substrate support unit.

14. The plasma processing device according to claim 13, characterized in that: The plurality of zones include: at least one first partition located below the edge ring; and at least one second partition located inside the at least one first partition and adjacent to the at least one first partition, The control unit is configured to determine a thickness of the plasma sheath above the edge ring and a thickness of the plasma sheath above the at least one second partition as the thickness of the plasma sheath above each of the plurality of partitions.

15. The plasma processing device according to claim 13, characterized in that: The plurality of partitions include: at least one first partition located below the edge ring; and at least one second partition located below the substrate, The control unit is further configured as follows: The height direction position of the upper end of the plasma sheath above the edge ring can be obtained according to the thickness of the plasma sheath above the at least one first partition. And based on the thickness of the plasma sheath above the at least one second partition, the height direction position of the upper end of the plasma sheath above the substrate is calculated.

16. The plasma processing device according to claim 14, characterized in that: The control unit is further configured to control the regulator so that the thickness of the plasma sheath above the at least one first partition is substantially the same as the thickness of the plasma sheath above the at least one first partition. The regulator can be controlled by the control unit to adjust a voltage applied to the edge ring or change a position of the edge ring in a vertical direction.

17. The plasma processing device according to claim 15, characterized in that: The control unit is further configured to control the regulator so that the height direction position of the upper end of the plasma sheath above the at least one first partition and the height direction position of the upper end of the plasma sheath above the at least one first partition are substantially the same. The regulator can be controlled by the control unit to adjust a voltage applied to the edge ring or change a position of the edge ring in a vertical direction.

18. The plasma processing device according to claim 13, characterized in that: The control unit is further configured to determine a traveling direction of ions from the plasma in a space above each of the plurality of sections based on a thickness of the plasma sheath above each of the plurality of sections.

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