Lower electrode mechanism and substrate processing apparatus

Abstract

This bottom electrode mechanism is used for plasma processing and has: a base portion to which high-frequency power is applied when the plasma processing is performed; a dielectric body portion disposed on the upper surface of the base portion; and an induction heating mechanism. The induction heating mechanism comprises: an induction heating element heated by an induced magnetic field; and a magnetic field generation portion provided inside the base portion and generating the induced magnetic field.

Description

Technical Field

[0001] The present disclosure relates to a lower electrode mechanism and a substrate processing apparatus thereof.

Background Art

[0002] Patent Document 1 discloses a plasma processing apparatus having a heater power source electrically connected to a heating element provided in a mounting table for supporting an object to be processed via a heater power supply line, and attenuating or blocking high-frequency noise entering the heater power supply line from the heating element toward the heater power source by a filter provided on the heater power supply line.

Prior Art Documents

Patent Documents

[0003]

Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0004] The technology according to the present disclosure provides a lower electrode mechanism capable of wirelessly generating heat for a heating element provided in an electrostatic chuck that adsorbs and holds a substrate.

Means for Solving the Problems

[0005] One aspect of the present disclosure is a lower electrode mechanism used for plasma processing, having a base portion to which high-frequency power is applied during the plasma processing, a dielectric portion disposed on the upper surface of the base portion, and an induction heating mechanism, wherein the induction heating mechanism includes an induction heating element heated by an induction magnetic field and a magnetic field generating portion provided inside the base portion for generating the induction magnetic field. , the base portion includes a main body member made of a non-magnetic conductive member, and a lid member made of a non-magnetic conductive member and having a concave portion formed on the lower surface thereof such that the magnetic field generation portion is accommodated therein when disposed on the upper surface of the main body member, and the lid member transmits the induced magnetic field generated from the magnetic field generation portion.

Effects of the Invention

[0006] According to the present disclosure, a lower electrode mechanism capable of wirelessly generating heat can be provided for a heating element provided in an electrostatic chuck that adsorbs and holds a substrate.

Brief Description of the Drawings

[0007]

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Embodiments for Carrying Out the Invention

[0008] In the manufacturing process of a semiconductor device, by exciting a processing gas supplied into a chamber to generate plasma, various plasma processes such as an etching process, a film forming process, and a diffusion process are performed on a semiconductor substrate (hereinafter simply referred to as "substrate") supported by a substrate support. The substrate support for supporting the substrate is provided with, for example, an electrostatic chuck that adsorbs and holds the substrate on the mounting surface by a Coulomb force or the like.

[0009] In the above-described plasma process, in order to enhance the uniformity of process characteristics with respect to the substrate, it is required to appropriately adjust the temperature distribution of the substrate to be processed. The temperature distribution of the substrate during the plasma process is adjusted, for example, by adjusting the surface temperature of the electrostatic chuck and correcting the heat transfer amount distribution from the electrostatic chuck.

[0010] By the way, when adjusting the temperature distribution of the substrate by adjusting the surface temperature of the electrostatic chuck as described above, a plurality of heating elements (for example, heaters) are provided inside the electrostatic chuck, and the surface temperature of the substrate is adjusted for each of a plurality of temperature control regions defined by these heating elements. However, when a plurality of heating elements are provided inside the electrostatic chuck in this way, there is a problem that power supply cables corresponding to the number of the aforementioned temperature control regions are required, and these power supply cables occupy the lower space of the electrostatic chuck.

[0011] In addition, in the power supply cable connected to the heating element, a part of the high frequency applied from the RF (Radio Frequency) power supply to the substrate support during plasma generation may enter as common mode noise, which may cause abnormal discharge or reverse flow of high frequency power. In order to remove such noise components from the power supply cable, for example, it is necessary to provide an RF cut filter on the power supply cable. However, when providing such an RF cut filter in this way, the lower space of the electrostatic chuck will be further occupied. In particular, as the RF frequency becomes lower, it is necessary to increase the coil of the RF cut filter, that is, to increase the impedance, so the problem related to the occupation of the lower space of the electrostatic chuck becomes prominent.

[0012] In addition, since the RF cut filter has frequency characteristics, in order to appropriately remove the noise components from the power supply cable, it is necessary to select an RF cut filter corresponding to the frequency of the applied RF power and optimize the noise component removal ability. However, in recent plasma processing, RF power of different frequencies is applied according to the plasma processing process, so it has been very difficult to remove all noise components with a single RF cut filter. In other words, in order to appropriately remove the noise components, it is necessary to provide a plurality of RF cut filters on the power supply cable, and the problem related to the occupation of the lower space of the electrostatic chuck becomes more prominent.

[0013] Patent Document 1 discloses a plasma processing apparatus in which an RF cut filter (filter unit) for attenuating or blocking such noise components (high frequency noise) is provided on the power supply cable (line) of the heating element. However, Patent Document 1 does not describe that the lower space of the electrostatic chuck is occupied by the power supply cable or the RF cut filter as described above, and there is room for improvement from this perspective.

[0014] The technology according to the present disclosure has been made in view of the above circumstances, and provides a lower electrode mechanism capable of wirelessly generating heat for a heating element provided in an electrostatic chuck that adsorbs and holds a substrate. Hereinafter, a plasma processing system including a substrate support as a lower electrode mechanism according to the present embodiment will be described with reference to the drawings. In the present specification and drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant description is omitted.

[0015] <Plasma processing apparatus> First, the plasma processing system according to the present embodiment will be described. FIG. 1 is a longitudinal sectional view showing an outline of the configuration of the plasma processing system according to the present embodiment.

[0016] The plasma processing system includes a capacitively coupled plasma processing apparatus 1 and a control unit 2. The plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply unit 20, a power supply 30, and an exhaust system 40. The plasma processing apparatus 1 also includes a substrate support 11 and a gas introduction unit. The substrate support 11 is disposed in the plasma processing chamber 10. The gas introduction unit is configured to introduce at least one processing gas into the plasma processing chamber 10. The gas introduction unit includes a shower head 13. The shower head 13 is disposed above the substrate support 11. In one embodiment, the shower head 13 constitutes at least a part of the ceiling of the plasma processing chamber 10. Inside the plasma processing chamber 10, a plasma processing space 10s defined by the shower head 13, the side wall 10a of the plasma processing chamber 10, and the substrate support 11 is formed. The plasma processing chamber 10 has at least one gas supply port for supplying at least one processing gas to the plasma processing space 10s and at least one gas discharge port for discharging gas from the plasma processing space 10s. The side wall 10a is grounded. The shower head 13 and the substrate support 11 are electrically insulated from the plasma processing chamber 10.

[0017] The substrate support 11 includes a main body member 111 and a ring assembly 112 as a lower electrode mechanism. The upper surface of the main body member 111 has a central region 111a (substrate support surface) for supporting a substrate (wafer) W and an annular region 111b (ring support surface) for supporting the ring assembly 112. The annular region 111b surrounds the central region 111a in a plan view. The ring assembly 112 includes one or more annular members, and at least one of the one or more annular members is an edge ring.

[0018] As shown in FIG. 2, in one embodiment, the main body member 111 includes a base 113 and an electrostatic chuck 114 as a dielectric part. Also, in one embodiment, the base 113 includes a main body member 113a and a lid member 113b. The main body member 113a and the lid member 113b are laminated and joined via an adhesive member (not shown).

[0019] The main body member 113a is made of a non-magnetic conductive member such as an Al alloy, for example. The conductive member of the main body member 113a functions as a lower electrode. A recess 113c is formed on the upper surface of the main body member 113a, which is the surface on the side to which the lid member 113b is joined. An induction heating (IH) coil 115a, which will be described later, is disposed inside the recess 113c.

[0020] Also, a flow path C is formed inside the main body member 113a. A heat transfer medium (temperature control fluid) from a chiller unit (not shown) is circulated and supplied to the flow path C. By circulating the heat transfer medium through the flow path C, the ring assembly 112, the electrostatic chuck 114, which will be described later, and the substrate W are adjusted to a desired temperature. Note that, as the heat transfer medium, a refrigerant such as cooling water can be used.

[0021] In FIG. 2, the case where the flow path C is formed below the central region 111a (substrate W) in the main body member 113a is illustrated as an example, but the flow path C may be further formed below the annular region 111b corresponding to the ring assembly 112.

[0022] The lid member 113b is made of a non-magnetic conductive member such as an Al alloy, similar to the main body member 113a. The lid member 113b is formed, for example, in a disc shape with substantially the same diameter as the main body member 113a, and is joined to the upper surface of the main body member 113a so as to close the recess 113c formed in the main body member 113a. In other words, the lid member 113b can function as the top surface of the recess 113c formed in the main body member 113a.

[0023] Note that the base 113 acts as a casing for housing the induction heating coil 115a described later inside, and suppresses the intrusion of high-frequency waves from the RF power supply 31 described later into the induction heating coil 115a. From this perspective, it is desirable that the thickness of the lid member 113b is formed to allow the induction magnetic field M from the induction heating coil 115a described later to pass through, and not allow the high-frequency waves from the RF power supply 31 to pass through. More specifically, it is desirable that the thickness of the lid member 113b is greater than or equal to the skin depth at the frequency of the high-frequency waves from the RF power supply 31, so that the high-frequency waves can be blocked.

[0024] The electrostatic chuck 114 is laminated and joined to the upper surface of the base 113 (more specifically, the lid member 113b) via, for example, an adhesive member (not shown). The upper surface of the electrostatic chuck 114 has the aforementioned central region 111a and annular region 111b. Inside the electrostatic chuck 114, a first electrode 114a for adsorbing and holding the substrate W and a second electrode 114b for adsorbing and holding the ring assembly 112 are provided. Also, a magnetic body 115b described later is provided inside the electrostatic chuck 114. The electrostatic chuck 114 is configured by sandwiching the first electrode 114a, the second electrode 114b, and the magnetic body 115b between a pair of dielectric films made of a non-magnetic dielectric such as ceramics.

[0025] In FIG. 2, an example is illustrated where in the electrostatic chuck 114, the central region 111a that holds the substrate W on the upper surface and the annular region 111b that holds the ring assembly 112 on the upper surface are integrally formed. However, the configuration of the electrostatic chuck 114 is not limited to this, and the central region 111a and the annular region 111b of the electrostatic chuck 114 may be independently configured. By independently configuring the central region 111a and the annular region 111b in this way, the substrate W and the ring assembly 112 can be thermally separated, and temperature adjustment can be performed independently for each.

[0026] Also, as shown in FIG. 2, inside the substrate support 11, a heating mechanism 115 is provided as an induction heating mechanism that heats at least one of the ring assembly 112, the electrostatic chuck 114, and the substrate W. The heating mechanism 115 includes a plurality of induction heating coils 115a disposed inside the recess 113c of the main body member 113a, and a plurality of magnetic bodies 115b disposed inside the electrostatic chuck 114 corresponding to each of these induction heating coils 115a.

[0027] A heating power source 117 is connected to the induction heating coil 115a as a magnetic field generation unit via an inverter circuit 116. When power from the heating power source 117 is applied to the induction heating coil 115a, an induction magnetic field M is generated inside the base 113 as shown in FIG. 3.

[0028] The inverter circuit 116 controls the frequency of the power applied from the heating power source 117 to the induction heating coil 115a. Specifically, for example, the alternating current 50 / 60 Hz from the heating power source 117 is converted to a high frequency of several tens of kHz or more (for example, 100 kHz to 2 MHz). As the heating power source 117, any AC (Alternating Current) power source, for example, a general commercial AC power source, can be used. Note that the inverter circuit 116 and the heating power source 117 may be connected only one to the substrate support 11 as shown in FIG. 2, or a plurality of them may be provided, for example, for each temperature control region for adjusting the in-plane temperature of the substrate W.

[0029] The magnetic body 115b as an induction heating element is composed of, for example, a magnetic metal material (such as a material containing iron like carbon steel, silicon iron, stainless steel, permalloy, ferrite, etc.). As shown in FIG. 3, an induction current I (eddy current) is induced on the surface of the magnetic body 115b by the induction magnetic field M generated from the induction heating coil 115a. Then, the magnetic body 115b generates Joule heat according to the resistance value of the magnetic body 115b due to such an induction current I. Further, heat is generated due to the hysteresis loss (loss generated by the friction between Fe molecules) caused by the induction magnetic flux generated from the induction heating coil 115a in the magnetic body 115b.

[0030] Note that the induction heating element does not have to be a magnetic metal material as long as it is a material capable of obtaining sufficient heat generation by Joule heat generation due to eddy currents. For example, it may be aluminum, tungsten, tin, titanium, carbon, silicon, or silicon carbide.

[0031] Here, in the heating mechanism 115, in order to appropriately heat the magnetic body 115b by the induction magnetic field M emitted from the induction heating coil 115a, it is necessary to arrange the magnetic body 115b within the range where the induction magnetic field M from the induction heating coil 115a reaches inside the electrostatic chuck 114.

[0032] Therefore, in the substrate support according to the present embodiment, it is desirable to arrange the magnetic body 115b as low as possible (on the side of the base 113) inside the electrostatic chuck 114 and reduce the distance between the induction heating coil 115a and the magnetic body 115b. Further, for example, as shown in FIG. 4, a recess 114c may be formed on the lower surface of the electrostatic chuck 114, and the magnetic body 115b may be arranged inside the recess 114c. In other words, the magnetic body 115b may be arranged on the upper surface of the base 113 (more specifically, the lid member 113b).

[0033] Further, instead of or in addition to reducing the distance between the induction heating coil 115a and the magnetic body 115b in this way, a core material made of a high magnetic permeability material may be provided in the induction heating coil 115a to strengthen the induction magnetic field M emitted from the induction heating coil 115a.

[0034] Also, as shown in FIG. 5, in order to appropriately apply the induction magnetic field M emitted from the induction heating coil 115a to the magnetic body 115b, the induction heating coil 115a and the magnetic body 115b are arranged such that at least a part of them overlaps in a plan view. Desirably, as shown in FIG. 6, the entire surface of the induction heating coil 115a overlaps with the magnetic body 115b. By arranging the induction heating coil 115a and the magnetic body 115b so as to overlap in this way, the induction magnetic field M emitted from the induction heating coil 115a can be appropriately applied to the magnetic body 115b, and the magnetic body 115b can be heated. Further, by arranging the entire surface of the induction heating coil 115a to overlap with the magnetic body 115b as shown in FIG. 6, the induction magnetic field M emitted from the induction heating coil 115a at least upward can be utilized for induction heating without leakage.

[0035] As described above, in the plasma processing apparatus 1, in order to improve the uniformity of the process characteristics with respect to the substrate W, it is required to appropriately adjust the in-plane temperature distribution of the substrate W during plasma processing. In other words, it is required that the in-plane temperature of the substrate W be configured to be adjustable independently for each of a plurality of temperature control regions.

[0036] Therefore, a plurality of induction heating coils 115a and a plurality of magnetic bodies 115b are respectively provided inside the substrate support 11 according to the present embodiment. Specifically, as shown in FIG. 7, a plurality of induction heating coils 115a and magnetic bodies 115b are provided inside the substrate support 11 at a desired interval from each other. In this way, by providing a plurality of induction heating coils 115a and magnetic bodies 115b inside the substrate support 11 and adjusting the frequency of the high-frequency power applied to each induction heating coil 115a (or for each temperature control region formed by a group of induction heating coils 115a) by the inverter circuit 116, the surface temperature (in-plane temperature of the substrate W) distribution of the electrostatic chuck 114 can be appropriately adjusted.

[0037] From the viewpoint of appropriately adjusting the in-plane temperature distribution of the substrate W, a movable mechanism for approaching or separating a part of the magnetic field generating section from the induction heating element may be further provided. Specifically, for example, as shown in FIG. 8, an actuator Ac may be connected to the center of the induction heating coil 115a.

[0038] The induction heating coil 115a is covered with an insulating film Fm such as a polyimide film, and the actuator Ac and the induction heating coil 115a are insulated from each other. The actuator Ac may be made of an insulator such as quartz and insulated from the induction heating coil 115a. The tip of the actuator Ac is adhered to the insulating film Fm, and by driving the actuator Ac, a part of the induction heating coil 115a (the center part in the example shown in FIG. 9) approaches or separates from the induction heating element (magnetic body 115b). When a part (center part) of the induction heating coil 115a approaches the magnetic body 115b, the proximity part (center part) of the magnetic body 115b is heated more strongly than the separated part (end part) of the magnetic body 115b. On the other hand, when a part (center part) of the induction heating coil 115a separates from the magnetic body 115b, the separated part (center part) of the magnetic body 115b is heated less strongly than the proximity part (end part) of the magnetic body 115b.

[0039] Therefore, by providing a movable mechanism for approaching or separating a part of the magnetic field generating section from the induction heating element, the temperature distribution of the induction heating element (magnetic body 115b in the examples shown in FIGS. 8 and 9) can be controlled. As shown in FIG. 7, when a plurality of magnetic field generating sections are provided, a movable mechanism may be provided for each of all the magnetic field generating sections, or a movable mechanism may be provided only for some of the magnetic field generating sections. Further, a movable mechanism may be provided for each temperature control region formed by a group of magnetic field generating sections, or only for a part of the temperature control region formed by a group of magnetic field generating sections.

[0040] Thus, in the substrate support 11 according to this embodiment, the magnetic body 115b provided inside the electrostatic chuck 114 can be inductively heated wirelessly using the induction magnetic field M emitted from the induction heating coil 115a without being electrically connected to the induction heating coil 115a provided inside the main body member 113a. That is, the power supply cable that connected the heating element and the power supply in the conventional electrostatic chuck is reduced, and it is suppressed that the lower space of the electrostatic chuck 114 is occupied by these power supply cables. Further, since the power supply cable can be reduced in this way, the RF cut filter provided along with the power supply cable can be further reduced, and the occupation of the lower space of the electrostatic chuck 114 can be further suppressed.

[0041] Also, in this embodiment, no member having magnetism other than the magnetic body 115b is provided inside the electrostatic chuck 114, and the electrostatic chuck 114 itself is also composed of a non-magnetic dielectric such as ceramics. For this reason, the induction magnetic field M generated from the induction heating coil 115a can selectively heat only the magnetic body 115b which is the heating element.

[0042] Although not shown, the substrate support 11 may include a heat transfer gas supply unit configured to supply a heat transfer gas (backside gas) between the back surface of the substrate W and the upper surface of the electrostatic chuck 114.

[0043] Return to the description of FIG. 2. The showerhead 13 is configured to introduce at least one process gas from the gas supply unit 20 into the plasma processing space 10s. The showerhead 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and a plurality of gas introduction ports 13c. The process gas supplied from the gas supply unit 20 to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s from the plurality of gas introduction ports 13c. Further, the showerhead 13 includes a conductive member. The conductive member of the showerhead 13 functions as an upper electrode. Note that the gas introduction unit may include one or more side gas injectors (SGIs) attached to one or more openings formed in the sidewall 10a in addition to the showerhead 13.

[0044] The gas supply unit 20 may include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply unit 20 is configured to supply at least one process gas from the corresponding gas source 21 to the showerhead 13 via the corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Further, the gas supply unit 20 may include one or more flow modulation devices that modulate or pulse the flow rate of at least one process gas.

[0045] The power supply 30 includes an RF power supply 31 coupled to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power supply 31 is configured to supply at least one RF signal (RF power), such as a source RF signal and a bias RF signal, to the conductive member (lower electrode) of the substrate support 11 and / or the conductive member (upper electrode) of the shower head 13. Thereby, plasma is formed from at least one processing gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least a part of a plasma generation unit configured to generate plasma from one or more processing gases in the plasma processing chamber 10. Further, by supplying a bias RF signal to the lower electrode, a bias potential is generated on the substrate W, and the ion component in the formed plasma can be drawn into the substrate W.

[0046] In one embodiment, the RF power supply 31 includes a first RF generation unit 31a and a second RF generation unit 31b. The first RF generation unit 31a is coupled to the lower electrode and / or the upper electrode via at least one impedance matching circuit, and is configured to generate a source RF signal (source RF power) for plasma generation. In one embodiment, the source RF signal has a frequency in the range of 13 MHz to 150 MHz. In one embodiment, the first RF generation unit 31a may be configured to generate a plurality of source RF signals having different frequencies. The generated one or more source RF signals are supplied to the lower electrode and / or the upper electrode. The second RF generation unit 31b is coupled to the lower electrode via at least one impedance matching circuit, and is configured to generate a bias RF signal (bias RF power). In one embodiment, the bias RF signal has a frequency lower than that of the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 400 kHz to 13.56 MHz. In one embodiment, the second RF generation unit 31b may be configured to generate a plurality of bias RF signals having different frequencies. The generated one or more bias RF signals are supplied to the lower electrode. Also, in various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0047] As described above, the bias RF signal supplied from the RF power supply 31 to the lower electrode has conventionally been likely to enter as common-mode noise into the power supply cable connecting the heating element (for example, a heater or the like) and the power supply for the heating element. In this regard, in the present embodiment, since the power supply cable is not provided in the heating mechanism 115 as described above and the magnetic body 115b is wirelessly heated, noise does not enter the power supply cable in this way.

[0048] In addition, the power supply 30 may include a DC power supply 32 coupled to the plasma processing chamber 10. The DC power supply 32 includes a first DC generation unit 32a and a second DC generation unit 32b. In one embodiment, the first DC generation unit 32a is connected to the lower electrode and configured to generate a first DC signal. The generated first bias DC signal is applied to the lower electrode. In one embodiment, the first DC signal may be applied to other electrodes such as the adsorption electrode in the electrostatic chuck 114. In one embodiment, the second DC generation unit 32b is connected to the upper electrode and configured to generate a second DC signal. The generated second DC signal is applied to the upper electrode. In various embodiments, at least one of the first and second DC signals may be pulsed. Note that the first and second DC generation units 32a and 32b may be provided in addition to the RF power supply 31, or the first DC generation unit 32a may be provided in place of the second RF generation unit 31b.

[0049] The exhaust system 40 can be connected to, for example, a gas outlet 10e provided at the bottom of the plasma processing chamber 10. The exhaust system 40 may include a pressure regulating valve and a vacuum pump. The internal pressure of the plasma processing space 10s is adjusted by the pressure regulating valve. The vacuum pump may include a turbo molecular pump, a dry pump, or a combination thereof.

[0050] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to execute various processes described in the present disclosure. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to execute the various processes described herein. In one embodiment, part or all of the control unit 2 may be included in the plasma processing apparatus 1. The control unit 2 may include, for example, a computer 2a. The computer 2a may include, for example, a processing unit (CPU: Central Processing Unit) 2a1, a storage unit 2a2, and a communication interface 2a3. The processing unit 2a1 may be configured to perform various control operations based on a program stored in the storage unit 2a2. The storage unit 2a2 may include a RAM (Random Access Memory), a ROM (Read Only Memory), an HDD (Hard Disk Drive), an SSD (Solid State Drive), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a LAN (Local Area Network).

[0051] Although various exemplary embodiments have been described above, various additions, omissions, substitutions, and changes may be made without being limited to the exemplary embodiments described above. Also, it is possible to form other embodiments by combining elements in different embodiments.

[0052] For example, in this embodiment, the case where the plasma processing system has a capacitively coupled plasma (CCP) type plasma processing apparatus 1 has been described as an example, but the configuration of the plasma processing system is not limited thereto. For example, the plasma processing system may have a processing apparatus including a plasma generation unit such as inductively coupled plasma (ICP), electron-cyclotron-resonance plasma (ECR plasma), helicon wave plasma (HWP), or surface wave plasma (SWP). Further, a processing apparatus including various types of plasma generation units including an alternating current (AC) plasma generation unit and a direct current (DC) plasma generation unit may also be used.

[0053] Also, for example, in this embodiment, as shown in FIG. 2, the case where the concave portion 113c is formed on the upper surface of the main body member 113a of the substrate support 11 and the induction heating coil 115a is disposed inside the concave portion 113c has been described as an example, but the configuration of the substrate support 11 is not limited thereto. Specifically, as shown in FIG. 10, instead of the upper surface of the main body member 113a, the concave portion 113c may be formed on the lower surface of the lid member 113b, and the induction heating coil 115a may be disposed inside the concave portion 113c.

[0054] Also, in the above embodiment, the main body member 113a and the lid member 113b of the substrate support 11 are configured separately, but the main body member 113a and the lid member 113b may be integrally configured.

[0055] <Method for Processing Substrate by Plasma Processing Apparatus> Next, an example of a method for processing the substrate W in the plasma processing apparatus 1 configured as described above will be described. In the plasma processing apparatus 1, any plasma processing such as etching processing, film forming processing, diffusion processing, etc. is performed on the substrate W according to the purpose.

[0056] First, the substrate W is carried into the plasma processing chamber 10 and placed on the electrostatic chuck 114 of the substrate support 11. Next, a voltage is applied to the first electrode 114a of the electrostatic chuck 114, whereby the substrate W is adsorbed and held by the electrostatic chuck 114 by electrostatic force.

[0057] The substrate W adsorbed and held by the electrostatic chuck 114 is subjected to the target plasma processing while the in-plane temperature distribution is adjusted by the operation of the heating mechanism 115 provided inside the substrate support 11. Specifically, an induction magnetic field M is generated by applying high-frequency power from the heating power supply 117 to the induction heating coil 115a, whereby, for example, an induced current I (eddy current) is induced on the surface of the magnetic body 115b to inductively heat the magnetic body 115b, and the plasma processing is performed while the surface temperature of the substrate support 11 (electrostatic chuck 114) on which the substrate W is supported is adjusted.

[0058] The temperature adjustment method by the heating mechanism 115 will be described in more detail.

[0059] During the plasma processing of the substrate W in the plasma processing apparatus 1 by the heating mechanism 115, the surface temperature distribution of the substrate W is measured over time by a temperature sensor (not shown). Further, the target surface temperature of the substrate W during the plasma processing is output in advance to the control unit 2 according to, for example, the processing result and surface state of the substrate W in the previous process.

[0060] Therefore, during the plasma processing according to the present embodiment, the amount of current supplied to the induction heating coil 115a (the frequency of the high-frequency power) is adjusted (feedback control) by the inverter circuit 116 according to the difference between the surface temperature of the substrate W measured by the temperature sensor (not shown) and the target temperature of the substrate W output in advance to the control unit 2. The correlation between the current and the temperature, that is, the amount of current supply to the induction heating coil 115a required to correct the difference value between the target temperature and the measured temperature, is obtained in advance by an arbitrary method and output to the control unit 2.

[0061] Then, by correcting the difference value between the target temperature and the measured temperature for each of the induction heating coils 115a (or the temperature control region formed by a group of induction heating coils 115a) as described above, the entire surface of the substrate W can be appropriately adjusted to the target temperature.

[0062] Note that the correlation between the current and the temperature described above may change due to, for example, individual differences or deterioration over time of the heating mechanism 115, a temperature sensor (not shown), or other members. Therefore, in order to correct the influence of such deterioration over time, etc., it is desirable that the correlation between the current and the temperature be appropriately calibrated when the plasma processing apparatus 1 is started up or during maintenance.

[0063] Note that the timing of starting the adjustment of the surface temperature of the substrate support 11 (electrostatic chuck 114) is not particularly limited, and the temperature adjustment may be started after the substrate W is adsorbed and held by the electrostatic chuck 114, or the temperature adjustment may be started before adsorbing and holding the substrate W.

[0064] When the substrate W is adsorbed and held by the electrostatic chuck 114, next, the inside of the plasma processing chamber 10 is evacuated to a predetermined degree of vacuum. Next, a processing gas is supplied from the gas supply unit 20 to the plasma processing space 10s through the shower head 13. Further, source RF power for plasma generation is supplied from the first RF generation unit 31a to the lower electrode, whereby the processing gas is excited to generate plasma. At this time, bias RF power may be supplied from the second RF generation unit 31b. Then, in the plasma processing space 10s, the generated plasma acts on the substrate W to perform the target plasma processing on the substrate W.

[0065] When ending the plasma processing, the supply of the source RF power from the first RF generation unit 31a and the supply of the processing gas from the gas supply unit 20 are stopped. When bias RF power was supplied during the plasma processing, the supply of the bias RF power is also stopped.

[0066] Next, the temperature adjustment of the substrate W by the heating mechanism 115 and the adsorption and holding of the substrate W by the electrostatic chuck 114 are stopped, and the substrate W after plasma treatment and the electrostatic chuck 114 are discharged. Then, the substrate W is detached from the electrostatic chuck 114, and the substrate W is carried out of the plasma processing apparatus 1. Thus, a series of plasma processes are completed.

[0067] <Operational effects of the substrate support according to the present disclosure> As described above, according to the substrate support 11 according to the present embodiment, by configuring the heating mechanism 115 for adjusting the temperature of the substrate W with the induction heating coil 115a and the magnetic body 115b, the magnetic body 115b as a heating element can be wirelessly heated by the induction magnetic field M emitted from the induction heating coil 115a. That is, it is not necessary to connect a power supply cable to the magnetic body 115b as in the prior art, and the number of power supply cables arranged in the lower space of the substrate support 11 (electrostatic chuck 114) can be significantly reduced. Therefore, the occupation of the lower space can be suppressed, and the lower space can be effectively utilized. Further, according to the present embodiment, since it is not necessary to connect a power supply cable to the magnetic body 115b in this way, the RF cut filter conventionally provided along with the power supply cable can be further omitted. Thereby, the occupation of the lower space of the substrate support 11 (electrostatic chuck 114) can be further suppressed.

[0068] In addition, since the RF cut filter has frequency characteristics, conventionally, when RF power of different frequencies is applied to the substrate support 11 from the RF power supply, it is necessary to provide a plurality of RF cut filters in order to remove the noise components of these different frequencies respectively. However, in the present embodiment, even when RF power of different frequencies is applied to the substrate support 11 in this way, since the power supply cable is omitted, it is not necessary to provide an RF cut filter.

[0069] Also, in the above embodiments, the induction heating coil 115a is disposed inside a recess 113c formed in a base 113 made of, for example, an Al alloy or the like, and further, the upper part of the recess 113c is closed by a lid member 113b made of, for example, an Al alloy or the like. In other words, the base 113 acts as a casing for housing the induction heating coil 115a therein. Thereby, the high frequency applied from the RF power supply 31 to the substrate support 11 is appropriately suppressed from entering the induction heating coil 115a as noise components, that is, the occurrence of abnormal discharge and the reverse flow of high frequency power in the heating mechanism 115 is suppressed.

[0070] Also, according to the present embodiment, as shown in FIG. 7, a plurality of induction heating coils 115a and magnetic bodies 115b are disposed inside the substrate support 11, and by adjusting the frequency of the high frequency power applied to each induction heating coil 115a (or the temperature control region formed by a group of induction heating coils 115a), the surface temperature (in-plane temperature of the substrate W) distribution of the electrostatic chuck 114 can be appropriately adjusted.

[0071] In addition, when a plurality of induction heating coils 115a are arranged side by side in the substrate support 11 in this way, there is a possibility that the induction magnetic fields M respectively emitted from the adjacent induction heating coils 115a interfere with each other, and the magnetic bodies 115b corresponding to the respective induction heating coils 115a cannot be appropriately heated.

[0072] Therefore, in order to suppress the interference of such induction magnetic fields M, a magnetic shield 118 that reflects and absorbs the induction magnetic fields M may be provided around the induction heating coil 115a. As the magnetic shield 118, preferably, a plate-like member having a relative permeability μ>1, for example, stainless steel or the like can be selected.

[0073] FIG. 11 is an explanatory diagram showing an installation example of the magnetic shield 118. As shown in FIG. 11, the magnetic shield 118 is formed to be significantly larger than at least the induction heating coil 115a in the height direction along the side wall surface of the recess 113c of the base 113. In other words, the magnetic shield 118 is arranged such that its upper end position is at least higher than the upper end position of the induction heating coil 115a. Thereby, leakage of the induction magnetic field M emitted from the induction heating coil 115a in the adjacent direction is suppressed, interference of the induction magnetic field M is suppressed, and heating of the magnetic body 115b (substrate W) can be appropriately performed.

[0074] Also, as shown in FIG. 12, the magnetic shield 118 may be further provided along the bottom surface of the recess 113c of the base 113. By providing the magnetic shield 118 along the bottom surface of the recess 113c in this way, emission of the induction magnetic field M downward from the induction heating coil 115a is suppressed, and dielectric heating of the conductor provided below the electrostatic chuck 114 is suppressed. Also, a part of the induction magnetic field M emitted downward from the induction heating coil 115a is reflected upward (toward the magnetic body 115b side). Thereby, the directivity of the induction magnetic field M with respect to the magnetic body 115b side can be improved, and the heating efficiency of the magnetic body 115b (substrate W) can be improved.

[0075] In the embodiment, the magnetic shield 118 is provided on the side and / or below the induction heating coil 115a to particularly improve the directivity of the induction magnetic field M with respect to the upward direction. However, for example, when it is desired to improve the directivity of the induction magnetic field M with respect to other directions, the installation position of the magnetic shield 118 may be appropriately changed.

[0076] In the above embodiment, as shown in FIG. 7, the heating mechanism 115 is configured by arranging a plurality of induction heating coils 115a and magnetic bodies 115b side by side in the plane of the substrate support 11. However, the configuration of the heating mechanism 115 is not limited to this.

[0077] Specifically, for example, as shown in FIG. 13, only one induction heating coil 115a and one magnetic body 115b may be arranged in a size capable of heating the entire surface of the substrate W. Even in such a case, since there is no need to connect between the induction heating coil 115a and the magnetic body 115b with a power supply cable or the like, installation of an RF cut filter can be omitted, and occupation of the lower space of the substrate support 11 (electrostatic chuck 114) can be suppressed. Further, since connection by a power supply cable or the like is omitted in this way, entry of high-frequency waves applied from the RF power supply 31 to the substrate support 11 into the wiring system of the heating mechanism 115 as noise components is suppressed. However, when there is only one induction heating coil 115a and one magnetic body 115b provided in the plane of the substrate support 11 in this way, the in-plane temperature distribution of the substrate W cannot be controlled for each temperature control region as described above. From this viewpoint, it is desirable that a plurality, and preferably a large number, of induction heating coils 115a and magnetic bodies 115b be arranged side by side in the plane of the substrate support 11.

[0078] Note that, as described above, since the power supply cable is omitted in this embodiment, even when installation of the RF cut filter is omitted, entry of high-frequency waves caused by plasma into the wiring system of the heating mechanism 115 as noise components can be suppressed. However, when installation of the RF cut filter is omitted in this way, even if entry of high-frequency waves caused by plasma can be suppressed, noise components caused by parasitic capacitance may enter the wiring system of the heating mechanism 115. Therefore, a filter (not shown) for removing noise components caused by such parasitic capacitance may be provided on the substrate support 11.

[0079] Note that, in the above embodiment, as shown in FIGS. 2 and 4, a plurality of magnetic bodies 115b are arranged in one-to-one correspondence with each of the plurality of induction heating coils 115a in the plane of the substrate support 11. In other words, the same number of induction heating coils 115a and magnetic bodies 115b are provided in the plane of the substrate support 11, but the number of installations of each of the induction heating coils 115a and the magnetic bodies 115b is not limited to this.

[0080] Specifically, for example, as shown in FIG. 14, one magnetic body 115b may be configured to be induction heated by a plurality (two in the illustrated example) of induction heating coils 115a. Thereby, the number of magnetic bodies 115b disposed inside the substrate support 11 can be reduced, and the cost related to the installation of the heating mechanism 115 can be reduced.

[0081] In the above embodiments, the induction heating coil 115a is formed by a coil member having a circular shape in plan view, and the magnetic body 115b is formed by a plate member having a rectangular shape in plan view. However, the shapes of the induction heating coil 115a and the magnetic body 115b are not limited to this as long as the magnetic body 115b can generate heat by induction heating. That is, for example, the induction heating coil 115a may be formed in a rectangular shape in plan view or may be constituted by a plate member. Further, the magnetic body 115b may be formed in a circular shape in plan view, for example, or may be constituted by a coil member. Also, the shape of the concave portion 113c formed on the upper surface of the base 113 is not particularly limited and may be appropriately changed in order to dispose the induction heating coil 115a inside.

[0082] Also, for example, the heating mechanism 115 (induction heating coil 115a and magnetic body 115b) may be arranged concentrically with the substrate support 11 in plan view. In such a case, for example, as shown in FIG. 15, the arrangement may be determined so that the areas of the temperature control regions borne by the respective heating mechanisms 115 are substantially equal. Also, for example, when there is a temperature control region that needs to be particularly finely controlled (the outer side in the radial direction of the substrate W in the illustrated example), as shown in FIG. 16, the area for each temperature control region may be changed.

[0083] As described above, the induction heating coil 115a and the magnetic body 115b can be configured in any shape. However, from the viewpoint of uniformly adjusting the in-plane temperature of the electrostatic chuck 114 (substrate W), the shapes of the induction heating coil 115a and the magnetic body 115b are desirably shapes that can be evenly spread over the entire surface of the electrostatic chuck 114 (substrate W) (for example, rectangular arrangement or honeycomb arrangement).

[0084] In the above embodiments, the case where the base 113 and the electrostatic chuck 114 that constitute the main body member 111 of the substrate support 11 are directly laminated and provided has been described as an example. However, as shown in FIG. 17, a heat insulating layer In may be formed between the base 113 and the electrostatic chuck 114. The heat insulating layer In may be constituted by a vacuum heat insulating space formed by providing a sealing member S between the base 113 and the electrostatic chuck 114 as shown in FIG. 17, for example. Alternatively, an arbitrary heat insulating member may be provided between the base 113 and the electrostatic chuck 114 (not shown in the figure).

[0085] Thus, by forming the heat insulating layer In in the main body member 111 of the substrate support 11, the base 113 and the electrostatic chuck 114 are thermally separated. Thereby, heat transfer between the electrostatic chuck 114 and the base 113 whose temperature has risen by induction heating is suppressed. That is, the electrostatic chuck 114 (substrate W) can be heated more efficiently by the magnetic body 115b.

[0086] Further, when the heat insulating layer In is constituted by a vacuum heat insulating space as shown in FIG. 17, a heat transfer fluid (for example, brine or gas) may be configured to be able to flow through the vacuum heat insulating space. In other words, a fluid supply part (not shown) for supplying a heat transfer fluid to the vacuum heat insulating space and a fluid discharge part (not shown) for discharging the heat transfer fluid from the vacuum heat insulating space may be connected to the vacuum heat insulating space.

[0087] In such a case, for example, when no heat transfer fluid is flowing through the vacuum heat insulating space (the heat insulating layer In is in a vacuum state), the base 113 and the electrostatic chuck 114 are thermally separated, and the electrostatic chuck 114 (substrate W) can be efficiently heated by the heat generation of the magnetic body 115b. On the other hand, for example, when a heat transfer fluid is flowing through the vacuum heat insulating space, the base 113 and the electrostatic chuck 114 are thermally connected by the heat transfer fluid. That is, heat transfer occurs from the heated electrostatic chuck 114 to the base 113 through the heat transfer fluid, and thereby the electrostatic chuck 114 can be cooled. By configuring the heat transfer fluid to be able to flow through the vacuum insulation space in this way, by controlling the flow of the heat transfer fluid, in addition to heating for temperature adjustment of the electrostatic chuck 114, cooling can be more appropriately performed. Thereby, the adjustment of the surface temperature of the electrostatic chuck 114 (the temperature of the substrate W) can be more appropriately performed, that is, plasma treatment can be more appropriately performed on the substrate W.

[0088] The embodiments disclosed this time should be considered to be illustrative in all respects and not restrictive. The above embodiments may be omitted, substituted, or changed in various forms without departing from the scope and gist of the appended claims.

Explanation of Reference Numerals

[0089] 11 Substrate support 113 Base 114 Electrostatic chuck 115 Heating mechanism 115a Induction heating coil 115b Magnetic body W Substrate

Claims

1. A lower electrode mechanism used for plasma processing, comprising: a base portion to which high-frequency power is applied during the plasma processing; a dielectric portion disposed on the upper surface of the base portion; an induction heating mechanism; and having the induction heating mechanism comprising: an induction heating element heated by an induction magnetic field; a magnetic field generating portion provided inside the base portion for generating the induction magnetic field; and the base portion comprising: a main body member formed of a non-magnetic conductive member; a lid member formed of a non-magnetic conductive member and having a recess formed on its lower surface for accommodating the magnetic field generating portion therein by being disposed on the upper surface of the main body member; and the lid member transmitting the induction magnetic field generated from the magnetic field generating portion, the lower electrode mechanism.

2. A lower electrode mechanism used for plasma processing, comprising: a base portion to which high-frequency power is applied during the plasma processing; a dielectric portion disposed on the upper surface of the base portion; an induction heating mechanism; and having the induction heating mechanism comprising: an induction heating element heated by an induction magnetic field; a magnetic field generating portion provided inside the base portion for generating the induction magnetic field; and the base portion comprising: a main body member formed of a non-magnetic conductive member and having a recess formed on its upper surface for accommodating the magnetic field generating portion therein; a lid member formed of a non-magnetic conductive member and forming the top surface of the recess by being disposed on the upper surface of the main body member; and the lid member transmitting the induction magnetic field generated from the magnetic field generating portion, the induction heating element being disposed on the upper surface of the lid member, the lower electrode mechanism.

3. The lower electrode mechanism according to claim 1 or 2, wherein the main body member and the lid member are integrally formed.

4. The lower electrode mechanism according to claim 1 or 2, wherein the induction heating element is disposed inside the dielectric portion.

5. The lower electrode mechanism according to claim 1 or 2, wherein the induction heating element is disposed such that at least a part thereof overlaps with the magnetic field generating portion in a plan view.

6. The lower electrode mechanism according to claim 5, wherein the induction heating element is disposed such that the entire surface thereof overlaps with the magnetic field generating portion in a plan view.

7. The lower electrode mechanism according to claim 1 or 2, wherein the induction heating element is formed of a plate member or a coil member.

8. The induction heating element is an iron-containing material including any one of carbon steel, silicon iron, stainless steel, permalloy, or ferrite, or is composed of at least any one of aluminum, tungsten, tin, titanium, carbon, silicon, or silicon carbide. The lower electrode mechanism according to claim 1 or 2.

9. The dielectric part is composed of a non-magnetic dielectric member. The lower electrode mechanism according to claim 1 or 2.

10. The induction heating mechanism heats at least the dielectric part. The induction heating mechanism includes a plurality of the induction heating elements and a plurality of the magnetic field generating parts. The induction heating mechanism is configured to be able to heat the dielectric part independently for each of a plurality of predetermined temperature control regions. The lower electrode mechanism according to claim 1 or 2.

11. In the induction heating mechanism, the same number of the induction heating elements and the magnetic field generating parts are provided such that one of the magnetic field generating parts corresponds to one of the induction heating elements. The lower electrode mechanism according to claim 10.

12. In the induction heating mechanism, a plurality of the induction heating elements are provided so as to correspond to one of the magnetic field generating parts. The lower electrode mechanism according to claim 10.

13. A magnetic shield for suppressing the transmission of the induction magnetic field is provided so as to surround the magnetic field generating part in a plan view. The lower electrode mechanism according to claim 1 or 2.

14. A magnetic shield for suppressing the transmission of the induction magnetic field is provided below the magnetic field generating part. The lower electrode mechanism according to claim 1 or 2.

15. The magnetic shield is composed of a member having a relative permeability of 1 or less. The lower electrode mechanism according to claim 13.

16. The magnetic shield is composed of a member having a relative permeability of 1 or less. The lower electrode mechanism according to claim 14.

17. The lower electrode mechanism according to claim 1 or 2 further includes a driving mechanism for approaching or separating a part of the magnetic field generating part from the induction heating element.

18. A substrate processing apparatus for processing a substrate, A processing chamber that defines a processing space for the substrate, The lower electrode mechanism according to claim 10 disposed inside the processing space, A gas supply unit that supplies a processing gas to the processing space, A plasma generation unit that supplies high-frequency power to the lower electrode mechanism to generate plasma in the processing space with the processing gas. A substrate processing apparatus having.

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