Lower electrode mechanism, plasma processing device and substrate processing method

Abstract

The present invention provides a lower electrode mechanism that can wirelessly heat a heating element disposed in an electrostatic clamp of an adsorption and holding substrate. The lower electrode mechanism of the present invention is used for plasma processing and includes: a base portion, which is subjected to radio frequency power during plasma processing; a dielectric portion disposed on the top surface of the base portion; and an induction heating mechanism; the induction heating mechanism includes: an induction heating element, which is heated by an induction magnetic field; and a magnetic field generating portion disposed inside the base portion, which generates the induction magnetic field.

Description

[Technical Field]

[0001] This invention relates to a lower electrode mechanism, a substrate processing apparatus, and a substrate processing method. [Previous Technology]

[0002] Patent Document 1 discloses a plasma processing apparatus having a heater power supply, which is electrically connected to a heating element disposed on a platform supporting the object to be processed via a heater power supply line; a filter disposed on the heater power supply line attenuates or blocks high-frequency noise from the heating element to the heater power supply and into the heater power supply line. [Prior Art Documents] [Patent Documents]

[0003] [Patent Document 1] Japanese Patent Application Publication No. 2015-173027 [Summary of the Invention]

[0004] [The problem that the invention is intended to solve]

[0005] The present invention provides a lower electrode mechanism that can wirelessly heat a heating element disposed in an electrostatic clamp of an adsorption and holding substrate. [Technical Means for Solving the Problem]

[0006] One embodiment of the present invention is a lower electrode mechanism for plasma processing, comprising: a base portion to which radio frequency power is applied during plasma processing; a dielectric portion disposed on the top surface of the base portion; and an induction heating mechanism; the induction heating mechanism includes: an induction heating element heated by an induction magnetic field; and a magnetic field generating portion disposed inside the base portion to generate the induction magnetic field. [Effects of the Invention]

[0007] According to the present invention, a lower electrode mechanism is provided to wirelessly heat a heating element disposed in an electrostatic clamp of an adsorption and holding substrate.

Implementation Method

[0009] In the manufacturing process of semiconductor devices, plasma is generated by exciting the processing gas supplied to the chamber, and various plasma treatments such as etching, film formation, and diffusion are performed on the semiconductor substrate (hereinafter referred to as "substrate") supported by the substrate support. In the substrate support that supports the substrate, there are electrostatic chucks that adsorb and hold the substrate to the mounting surface by means of, for example, Coulomb force.

[0010] In the above-described plasma processing, in order to improve the uniformity of the processing characteristics of the substrate, it is required to appropriately adjust the temperature distribution of the substrate to be processed. The temperature distribution of the substrate during plasma processing is adjusted, for example, by "adjusting the surface temperature of the electrostatic chuck to correct the heat transfer distribution from the electrostatic chuck".

[0011] Furthermore, as described above, when adjusting the temperature distribution of the substrate by adjusting the surface temperature of the electrostatic chuck, a plurality of heating elements (e.g., heaters) are provided inside the electrostatic chuck, and the surface temperature of the substrate is adjusted for each of the plurality of temperature-adjusting zones defined by these heating elements. However, when a plurality of heating elements are provided inside the electrostatic chuck, there is a problem that "supply cables are required in accordance with the number of the aforementioned temperature-adjusting zones, resulting in these supply cables occupying the lower space of the electrostatic chuck."

[0012] Furthermore, in the power supply cable connected to the heating element, a portion of the radio frequency applied to the substrate support from the RF (Radio Frequency) power supply when plasma is generated enters as common-mode noise, which may lead to abnormal discharge or RF power reverse current. In order to remove this noise component from the power supply cable, an RF cutoff filter must be provided on the power supply cable, for example. However, if such an RF cutoff filter is provided, the lower space of the electrostatic clamp will be occupied more. In particular, the lower the RF frequency, the larger the coil of the RF cutoff filter, that is, due to the need for high impedance, the problem of occupying the lower space of the electrostatic clamp becomes significant.

[0013] Furthermore, since RF cutoff filters have frequency characteristics, in order to properly remove noise components from the power supply cable, it is necessary to select an RF cutoff filter that corresponds to the frequency of the applied RF power to optimize the noise removal capability. However, since in recent plasma processing, different frequencies of RF power are applied depending on the plasma processing procedure, it is very difficult to remove all noise components with a single RF cutoff filter. In other words, multiple RF cutoff filters must be installed on the power supply cable to properly remove noise components, which makes the problem of occupying space under the electrostatic clamp more significant.

[0014] Patent Document 1 discloses a plasma processing apparatus in which an RF cutoff filter (filter unit) is provided on the power supply cable (line) of the heating element to attenuate or block the noise component (radio frequency noise). However, Patent Document 1 does not describe the problem of the power supply cable or RF cutoff filter occupying the lower space of the electrostatic clamp as described above, so there is room for improvement in this regard.

[0015] The present invention was made in view of the above-mentioned circumstances. The present invention provides a lower electrode mechanism that can wirelessly heat a heating element provided in an electrostatic chuck for adsorbing and holding a substrate. Hereinafter, a plasma processing system having a substrate support body as the lower electrode mechanism according to the present embodiment will be described with reference to the drawings. In this specification and drawings, repeated descriptions are omitted by giving the same reference numerals to elements that have substantially the same functional configuration.

[0016] <Plasma Treatment Apparatus> First, the plasma treatment system according to this embodiment will be described. Figure 1 is a longitudinal sectional view showing the general structure of the plasma treatment system according to this embodiment.

[0017] 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. Furthermore, the plasma processing apparatus 1 includes a substrate support 11 and a gas inlet unit. The substrate support 11 is disposed within the plasma processing chamber 10. The gas inlet unit introduces at least one processing gas into the plasma processing chamber 10. The gas inlet unit includes a spray head 13. The spray head 13 is disposed above the substrate support 11. In one embodiment, the spray head 13 constitutes at least a portion of the ceiling of the plasma processing chamber 10. Inside the plasma processing chamber 10, a plasma processing space 10s is formed, defined by the spray head 13, the sidewall 10a of the plasma processing chamber 10, and the substrate support 11. 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 outlet for discharging gas from the plasma processing space 10s. The sidewall 10a is grounded. The spray head 13 and the substrate support 11 are electrically insulated from the plasma processing chamber 10.

[0018] The substrate support 11 includes a body member 111 and a ring assembly 112 as a lower electrode mechanism. The top surface of the body member 111 has a central region 111a (substrate support surface) for supporting the 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 when viewed from above. The ring assembly 112 includes one or more annular members, at least one of which is an edge ring.

[0019] As shown in FIG2, in one embodiment, the body member 111 includes a base 113 and an electrostatic clamp 114 serving as a dielectric portion. In another embodiment, the base 113 includes a body member 113a and a cover member 113b. The body member 113a and the cover member 113b are stacked and joined via an adhesive member (not shown).

[0020] The main body member 113a is made of a non-magnetic conductive component, such as an Al alloy. The conductive component of the main body member 113a functions as a lower electrode. A recess 113c is formed on the surface of the main body member 113a that is adjacent to the connecting cover member 113b. An induction heating coil 115a, which will be described later, is disposed inside the recess 113c.

[0021] Furthermore, a flow channel C is formed inside the main body component 113a. A heat transfer medium (temperature regulating fluid) from the quench unit (not shown) is circulated and supplied in the flow channel C. Furthermore, by circulating the heat transfer medium in the flow channel C, the ring assembly 112, the electrostatic clamp 114 (described later), and the substrate W are adjusted to the desired temperature. Furthermore, a cooling medium such as cooling water can be used as the heat transfer medium.

[0022] Furthermore, in FIG2, the example shown is that the flow channel C is formed in the lower part of the central region 111a (substrate W) in the body member 113a, but the flow channel C may also be formed in the lower part of the annular region 111b in correspondence with the ring assembly 112.

[0023] The cover member 113b is the same as the body member 113a, and is made of a non-magnetic conductive component such as an Al alloy. The cover member 113b is, for example, shaped as a circular plate with approximately the same diameter as the body member 113a, and is joined to the top surface of the body member 113a to close the recess 113c formed in the body member 113a. In other words, the cover member 113b can function as the "top surface of the recess 113c formed in the body member 113a".

[0024] Furthermore, the base 113 functions as a housing to house the induction heating coil 115a (described later) and suppresses the intrusion of radio frequency from the RF power supply 31 (described later) into the induction heating coil 115a. From this viewpoint, the thickness of the cover member 113b is preferably formed such that the induced magnetic field M from the induction heating coil 115a is transmitted, but the radio frequency from the RF power supply 31 is not transmitted. More specifically, the thickness of the cover member 113b is preferably a thickness above the skin effect (skin depth) of the frequency of the radio frequency from the RF power supply 31, so as to cut off the radio frequency.

[0025] The electrostatic chuck 114 is stacked and joined to the top surface of the base 113 (more specifically, the cover member 113b) via, for example, an adhesive member (not shown). The top surface of the electrostatic chuck 114 has the aforementioned central region 111a and an annular region 111b. Inside the electrostatic chuck 114, there is a first electrode 114a for adsorbing and holding the substrate W, and a second electrode 114b for adsorbing and holding the ring assembly 112. Furthermore, inside the electrostatic chuck 114, there is a magnetic body 115b, which will be described later. The electrostatic chuck 114 is constructed, for example, by "clamping 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 ceramic".

[0026] Furthermore, Figure 2 illustrates an example in which the "central region 111a holding the substrate W on the top surface" and the "annular region 111b holding the ring assembly 112 on the top surface" of the electrostatic chuck 114 are integrally formed. However, the configuration of the electrostatic chuck 114 is not limited to this; the central region 111a and the annular region 111b of the electrostatic chuck 114 can also be formed independently. By forming the central region 111a and the annular region 111b independently, the substrate W and the ring assembly 112 can be thermally separated, and temperature adjustment can be performed independently for each.

[0027] As shown in FIG2, a heating mechanism 115, which is an induction heating mechanism, is provided inside the substrate support 11 to heat 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 body member 113a; and a plurality of magnetic bodies 115b, corresponding to each of the induction heating coils 115a, disposed inside the electrostatic chuck 114.

[0028] The heating power supply 117 is connected to the induction heating coil 115a, which serves as a magnetic field generating unit, via an inverter circuit 116. The induction heating coil 115a generates an induced magnetic field M inside the base 113 as shown in FIG3 by applying power from the heating power supply 117.

[0029] The inverter circuit 116 controls the frequency of the power applied from the heating power supply 117 to the induction heating coil 115a. Specifically, for example, it converts the AC 50 / 60Hz from the heating power supply 117 into a radio frequency (RF) of tens of kHz or higher (e.g., 100kHz to 2MHz). The heating power supply 117 can be any AC (Alternating Current) power supply, such as a general commercial AC power supply. Furthermore, as shown in FIG2, the inverter circuit 116 and the heating power supply 117 can be connected to only one for the substrate support 11, or multiple can be provided, for example, for each temperature adjustment area used to adjust the in-plane temperature of the substrate W.

[0030] The magnetic body 115b, which serves as the induction heating element, is made of, for example, a magnetic metallic material (such as carbon steel, silicon iron, stainless steel, high-permeability alloys, and iron-containing materials like ferrite). As shown in FIG3, an induced current I (eddy current) is generated on the surface of the magnetic body 115b by the induced magnetic field M generated from the induction heating coil 115a. Furthermore, the magnetic body 115b generates Joule heating based on its resistance value due to this induced current I. Additionally, the induced magnetic flux generated from the induction heating coil 115a generates heat due to hysteresis losses (losses caused by friction between Fe molecules) generated in the magnetic body 115b.

[0031] Furthermore, the induction heating element can be any material that can generate sufficient heat through Joule heating produced by eddy currents, and can also be a non-magnetic metallic material. For example, it can also be: aluminum, tungsten, tin, titanium, carbon, silicon, silicon carbide.

[0032] Here, in the heating mechanism 115, since the magnetic body 115b is properly heated by the induced magnetic field M released from the induction heating coil 115a, the magnetic body 115b must be positioned within the range that the induced magnetic field M from the induction heating coil 115a can reach inside the electrostatic chuck 114.

[0033] Therefore, in the substrate support according to this embodiment, it is desirable to arrange the magnetic body 115b as low as possible (on the base 113 side) inside the electrostatic chuck 114 to shorten the distance between the induction heating coil 115a and the magnetic body 115b. Furthermore, for example, as shown in FIG4, a recess 114c may be formed on the bottom 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 also be arranged on the top surface of the base 113 (more specifically, the cover member 113b).

[0034] Alternatively, a core material made of a high permeability material can be placed on the induction heating coil 115a to enhance the induced magnetic field M released from the induction heating coil 115a, instead of shortening the distance between the induction heating coil 115a and the magnetic body 115b, or both can be used in parallel.

[0035] Furthermore, as shown in FIG5, in order to ensure that the induced magnetic field M released from the induction heating coil 115a properly acts on the magnetic body 115b, the induction heating coil 115a and the magnetic body 115b are configured such that at least a portion overlaps when viewed from above. Preferably, as shown in FIG6, the entire surface of the induction heating coil 115a overlaps with the magnetic body 115b. By configuring the induction heating coil 115a and the magnetic body 115b to overlap in this way, the induced magnetic field M released from the induction heating coil 115a can properly act on the magnetic body 115b, causing the magnetic body 115b to heat up. Furthermore, as shown in FIG6, by configuring the entire surface of the induction heating coil 115a to overlap with the magnetic body 115b, at least the induced magnetic field M released upward from the induction heating coil 115a can be utilized for induction heating without omission.

[0036] Furthermore, as described above, in the plasma processing apparatus 1, in order to improve the uniformity of the processing characteristics of 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 can be adjusted independently for each of the plurality of temperature-adjusting regions.

[0037] Therefore, inside the substrate support 11 according to this embodiment, a plurality of induction heating coils 115a and a plurality of magnetic bodies 115b are respectively provided as described above. Specifically, as shown in FIG7, the plurality of induction heating coils 115a and magnetic bodies 115b are provided inside the substrate support 11 with a desired interval between them. In this way, by providing a plurality of induction heating coils 115a and magnetic bodies 115b inside the substrate support 11, and by adjusting the frequency of the radio frequency power applied to each induction heating coil 115a (or, each temperature-adjusting region formed by a group of induction heating coils 115a) by means of the inverter circuit 116, the surface temperature (in-plane temperature of the substrate W) distribution of the electrostatic chuck 114 can be appropriately adjusted.

[0038] Furthermore, from the viewpoint of appropriately adjusting the in-plane temperature distribution of the substrate W, a movable mechanism can be further provided to bring a portion of the magnetic field generating part closer to or further away from the induction heating element. Specifically, for example, as shown in FIG8, an actuator 120 can be connected to the center of the induction heating coil 115a.

[0039] The induction heating coil 115a is covered with an insulating film 119 such as polyimide film to insulate the actuator 120 from the induction heating coil 115a. Alternatively, the actuator 120 can be made of an insulator such as quartz and insulated from the induction heating coil 115a. The front end of the actuator 120 is bonded to the insulating film 119, and by driving the actuator 120, a portion of the induction heating coil 115a (in the example shown in FIG. 9, the center portion of the induction heating coil 115a) is brought closer to or further away from the induction heating element (magnetic body 115b). By bringing a portion (center portion) of the induction heating coil 115a closer to the magnetic body 115b, the closer portion (center portion) of the magnetic body 115b receives stronger heating than the farther portion (end portion) of the magnetic body 115b. On the other hand, by moving a portion (center) of the induction heating coil 115a away from the magnetic body 115b, the portion (center) of the magnetic body 115b that is away from the magnetic body 115b will be heated less than the portion (end) of the magnetic body 115b that is close to it.

[0040] Thus, by providing a movable mechanism that moves a portion of the magnetic field generating unit closer to or further away from the induction heating element, the temperature distribution of the induction heating element (magnetic body 115b in the examples shown in Figures 8 and 9) can be controlled. Furthermore, as shown in Figure 7, when multiple magnetic field generating units are provided, movable mechanisms can be provided for each of the magnetic field generating units, or only for a portion of the magnetic field generating units. Moreover, movable mechanisms can be provided for each temperature-regulating region formed by a group of magnetic field generating units, or only for a portion of each temperature-regulating region formed by a group of magnetic field generating units.

[0041] Thus, in the substrate support 11 according to this embodiment, the magnetic body 115b provided inside the electrostatic chuck 114 can wirelessly generate heat by utilizing the induced magnetic field M released from the induction heating coil 115a without being electrically connected to the induction heating coil 115a provided inside the body member 113a. That is, the power supply cable connecting the heating element and the power supply in conventional electrostatic chucks can be reduced, and the situation where the lower space of the electrostatic chuck 114 is occupied by such power supply cables can be suppressed. Furthermore, since the power supply cables can be reduced in this way, the RF cutoff filter provided with the power supply cables can be further reduced, thereby further suppressing the occupation of the lower space of the electrostatic chuck 114.

[0042] Furthermore, in this embodiment, no other magnetic components are provided inside the electrostatic chuck 114 except for the magnetic body 115b, and the electrostatic chuck 114 itself is also made of a non-magnetic dielectric material such as ceramic. Therefore, the induced magnetic field M generated by the induction heating coil 115a can selectively heat only the heating element, i.e., the magnetic body 115b.

[0043] Furthermore, although the illustration is omitted, the substrate support 11 may also include a heat transfer gas supply section to supply heat transfer gas (back gas) between the back surface of the substrate W and the top surface of the electrostatic chuck 114.

[0044] Returning to the description of Figure 2. The spray head 13 introduces at least one processing gas from the gas supply unit 20 into the plasma processing space 10s. The spray head 13 includes: at least one gas supply port 13a, at least one gas diffusion chamber 13b, and a plurality of gas inlets 13c. The processing gas supplied from the gas supply unit 20 to the gas supply port 13a is introduced into the plasma processing space 10s through the gas diffusion chamber 13b and the plurality of gas inlets 13c. Furthermore, the spray head 13 includes a conductive member. The conductive member of the spray head 13 functions as an upper electrode. In addition to the spray head 13, the gas inlet may also include one or more side gas injectors (SGIs), which are installed in one or more openings formed on the sidewall 10a.

[0045] The gas supply unit 20 may also include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply unit 20 supplies at least one processing gas from corresponding gas sources 21 to the spray head 13 via corresponding flow controllers 22. Each flow controller 22 may also include, for example, a mass flow controller or a pressure-controlled flow controller. Furthermore, the gas supply unit 20 may also include one or more flow modulation elements to modulate or pulse the flow rate of at least one processing gas.

[0046] The power supply 30 includes an RF power supply 31, which is connected to the plasma processing chamber 10 via at least one impedance matching circuit. The RF power supply 31 supplies at least one RF signal (RF power), such as a plasma source RF signal and a bias RF signal, to the conductive members (lower electrode) of the substrate support 11 and / or the conductive members (upper electrode) of the spray head 13. Thereby, plasma is formed from at least one processing gas supplied to the plasma processing space 10s. Thus, the RF power supply 31 can function as at least part of a plasma generation section that generates plasma from one or more processing gases in the plasma processing chamber 10. Furthermore, by supplying a bias RF signal to the lower electrode, a bias potential can be generated on the substrate W to introduce the ionic components in the formed plasma into the substrate W.

[0047] In one embodiment, the RF power supply 31 includes a first RF generating unit 31a and a second RF generating unit 31b. The first RF generating unit 31a is connected to a lower electrode and / or an upper electrode via at least one impedance matching circuit to generate a plasma source RF signal (plasma source RF power) for plasma generation. In one embodiment, the plasma source RF signal has a frequency in the range of 13MHz to 150MHz. In one embodiment, the first RF generating unit 31a can also generate a plurality of plasma source RF signals with different frequencies. One or more plasma source RF signals are supplied to the lower electrode and / or the upper electrode. The second RF generating unit 31b is connected to the lower electrode via at least one impedance matching circuit to generate a bias RF signal (bias RF power). In one embodiment, the bias RF signal has a frequency lower than the plasma source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 400kHz to 13.56MHz. In one embodiment, the second RF generating unit 31b can also generate multiple bias RF signals with different frequencies. One or more bias RF signals are supplied to the lower electrode. Furthermore, in various embodiments, at least one of the plasma source RF signal and the bias RF signal can be pulsed.

[0048] As described above, the bias RF signal supplied from the RF power supply 31 to the lower electrode has historically been considered common-mode noise and could enter the power supply cable connecting the heating element (e.g., a heater) and the power supply cable for the heating element. In this embodiment, since no power supply cable is provided in the heating mechanism 115 as described above, and the magnetic body 115b is heated wirelessly, there is no such noise entering the power supply cable.

[0049] Furthermore, the power supply 30 also includes a DC power supply 32 connected to the plasma processing chamber 10. The DC power supply 32 includes a first DC generating unit 32a and a second DC generating unit 32b. In one embodiment, the first DC generating unit 32a is connected to the lower electrode and generates a first DC signal. The generated first bias DC signal is applied to the lower electrode. In one embodiment, the first DC signal can also be applied to other electrodes such as adsorption electrodes within the electrostatic chuck 114. In one embodiment, the second DC generating unit 32b is connected to the upper electrode and generates 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 can be pulsed. Furthermore, in addition to the RF power supply 31, the first and second DC generating units 32a and 32b can be provided, and the first DC generating unit 32a can be provided instead of the second RF generating unit 31b.

[0050] The exhaust system 40 may be connected to a gas outlet 10e, for example, located at the bottom of the plasma processing chamber 10. The exhaust system 40 may also include a pressure regulating valve and a vacuum pump. The pressure regulating valve can be used to adjust the internal pressure of the plasma processing space 10s. The vacuum pump may also include a turbomolecular pump, a dry pump, or a combination thereof.

[0051] The control unit 2 processes computer-executable commands to "cause the plasma processing apparatus 1 to perform the various steps described herein." The control unit 2 can control the elements of the plasma processing apparatus 1 to perform the various steps described herein. In one embodiment, part or all of the control unit 2 may also be included in the plasma processing apparatus 1. The control unit 2 may also include, for example, a computer 2a. The computer 2a may also include, for example, a processing unit (CPU: Central Processing Unit) 2a1, a storage unit 2a2, and a communication interface 2a3. The processing unit 2a1 can perform various control actions based on the program stored in the storage unit 2a2. The storage unit 2a2 may also include: RAM (Random Access Memory), ROM (Read Only Memory), HDD (Hard Disk Drive), SSD (Solid State Drive), or a combination thereof. The communication interface 2a3 can also communicate with the plasma processing device 1 via communication lines such as LAN (Local Area Network).

[0052] Although the above description has been directed to various exemplary embodiments, the present invention is not limited to the exemplary embodiments described above, and various additions, omissions, substitutions, and modifications can be made. Furthermore, elements in different embodiments can be combined to form other embodiments.

[0053] For example, in this embodiment, the plasma processing system is described using a capacitively coupled plasma processing device 1, but the configuration of the plasma processing system is not limited to this. For example, the plasma processing system may also have a processing device that includes the following plasma generation units: inductively coupled plasma (ICP), electron-cyclotron-resonance plasma (ECR), helicon wave plasma (HWP), or surface wave plasma (SWP). Furthermore, processing devices that include AC (alternating current) plasma generation units and DC (direct current) plasma generation units, and that contain various types of plasma generation units, may also be used.

[0054] For example, in this embodiment, the case shown in FIG2, in which a recess 113c is formed on the top surface of the main body member 113a of the substrate support 11, and an induction heating coil 115a is disposed inside the recess 113c, is described as an example. However, the configuration of the substrate support 11 is not limited to this. Specifically, as shown in FIG10, a recess 113c may also be formed on the bottom surface of the cover member 113b instead of forming a recess 113c on the top surface of the main body member 113a, and an induction heating coil 115a may be disposed inside the recess 113c.

[0055] Furthermore, in the above embodiments, the main body member 113a and the cover member 113b of the substrate support 11 are respectively provided, but the main body member 113a and the cover member 113b may also be integrally formed.

[0056] <Method for processing a substrate by means of a plasma processing apparatus> Next, an example of a method for processing a substrate W in a plasma processing apparatus 1 configured as described above will be described. Furthermore, in the plasma processing apparatus 1, any plasma processing such as etching, film formation, or diffusion is performed on the substrate W according to the purpose.

[0057] First, the substrate W is moved 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, thereby attracting and holding the substrate W to the electrostatic chuck 114 by electrostatic force.

[0058] The substrate W, which is adsorbed and held in the electrostatic chuck 114, is subjected to plasma treatment by adjusting the in-plane temperature distribution through the operation of the heating mechanism 115 provided inside the substrate support 11, and the required plasma treatment is applied. Specifically, while applying radio frequency power to the induction heating coil 115a from the heating power supply 117 to generate an induction magnetic field M, an induction current I (eddy current) is induced on the surface of the magnetic body 115b, thereby inducing the magnetic body 115b to heat it, thereby adjusting the surface temperature of the substrate support 11 (electrostatic chuck 114) supporting the substrate W, plasma treatment is performed.

[0059] The temperature adjustment method performed by the heating mechanism 115 will be further described in detail.

[0060] When plasma processing of the substrate W in the plasma processing apparatus 1 is performed by the heating mechanism 115, the surface temperature distribution of the substrate W is measured over time by a temperature sensor (not shown). Furthermore, the target surface temperature of the substrate W during plasma processing is output to the control unit 2 in advance, for example, based on the processing results and surface condition of the substrate W in the previous step.

[0061] Therefore, during plasma processing according to this embodiment, the amount of current (frequency of radio frequency power) supplied to the induction heating coil 115a is adjusted (feedback control) by the inverter circuit 116 based on 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 pre-output to the control unit 2. In order to correct the correlation between current and temperature, that is, to correct the difference between the target temperature and the measured temperature, the required current supply to the induction heating coil 115a is obtained in advance by any method and output to the control unit 2.

[0062] Furthermore, the correction of the difference between the target temperature and the measured temperature is performed on each induction heating coil 115a (or, each temperature adjustment area formed by a group of induction heating coils 115a) as described above, thereby appropriately adjusting the entire surface of the substrate W to the target temperature.

[0063] Furthermore, regarding the aforementioned correlation between current and temperature, it may sometimes change due to individual differences in the heating mechanism 115 or a temperature sensor (not shown), or other components, or due to degradation over time. Therefore, in order to correct for the effects of degradation over time, the correlation between current and temperature is expected to be properly corrected during startup and maintenance of the plasma processing apparatus 1.

[0064] Furthermore, the starting point for surface temperature adjustment of substrate support 11 (electrostatic chuck 114) is not particularly limited. Temperature adjustment can begin after substrate W is adsorbed and fixed in electrostatic chuck 114, or it can begin before substrate W is adsorbed and fixed in electrostatic chuck.

[0065] After the substrate W is held in place by the electrostatic chuck 114, the internal pressure of the plasma processing chamber 10 is reduced to a predetermined vacuum level. Then, processing gas is supplied to the plasma processing space 10s from the gas supply unit 20 via the spray head 13. Furthermore, plasma source RF power for plasma generation is supplied to the lower electrode from the first RF generation unit 31a, thereby exciting the processing gas to generate plasma. At this time, bias RF power can also be supplied from the second RF generation unit 31b. Furthermore, during the plasma processing space 10s, the substrate W is subjected to the required plasma processing by the action of the generated plasma.

[0066] When plasma processing ends, the supply of plasma source RF power from the first RF generation unit 31a and the supply of processing gas from the gas supply unit 20 are stopped. If bias RF power is supplied during plasma processing, the supply of bias RF power is also stopped.

[0067] 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 electrical neutralization of the substrate W and the electrostatic chuck 114 after plasma treatment is performed. Then, the substrate W is separated from the electrostatic chuck 114 and removed from the plasma treatment apparatus 1. In this way, a series of plasma treatments are completed.

[0068] <Effects of the Substrate Support According to the Invention> As described above, the substrate support 11 of this embodiment, by forming a heating mechanism 115 for regulating the temperature of the substrate W using an induction heating coil 115a and a magnetic body 115b, can wirelessly heat the magnetic body 115b, which serves as a heating element, using the induced magnetic field M released from the induction heating coil 115a. That is, since it is not necessary to connect the power supply cable to the magnetic body 115b as in the past, the number of power supply cables arranged in the lower space of the substrate support 11 (electrostatic clamp 114) can be greatly reduced, thus suppressing the occupation of the lower space and effectively utilizing the lower space. Furthermore, according to this embodiment, since it is not necessary to connect the power supply cable to the magnetic body 115b, the RF cutoff filter that is usually attached to the power supply cable can be further omitted. In this way, the occupation of the lower space of the substrate support 11 (electrostatic clamp 114) can be further suppressed.

[0069] Furthermore, since RF cutoff filters have frequency characteristics, in the past, when different frequencies of RF power were applied to the substrate support 11 from the RF power supply, multiple RF cutoff filters had to be provided in order to remove different noise components of those frequencies respectively. However, in this embodiment, even when different frequencies of RF power are applied to the substrate support 11, the power supply cable can be omitted, so there is no need to provide RF cutoff filters.

[0070] Furthermore, in the above embodiment, the induction heating coil 115 is disposed inside a recess 113c formed in a base 113 made of, for example, an Al alloy, etc., and the recess 113c is closed above by a cover member 113b made of, for example, an Al alloy, etc. In other words, the base 113 functions as a housing to house the induction heating coil 115a. In this way, the radio frequency applied from the RF power supply 31 to the substrate support 11 as noise can be appropriately suppressed from entering the induction heating coil 115a, and the occurrence of abnormal discharge or radio frequency power reverse current in the heating mechanism 115 can also be suppressed.

[0071] Furthermore, according to this embodiment, as shown in FIG7, a plurality of induction heating coils 115a and magnetic bodies 115b are arranged inside the substrate support 11. By adjusting the frequency of the radio frequency power applied to each induction heating coil 115a (or, each temperature-adjusting 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.

[0072] Furthermore, when a plurality of induction heating coils 115a are arranged side by side on the substrate support 11, the induced magnetic fields M released from adjacent induction heating coils 115a will interfere with each other. Therefore, there is a concern that the magnetic body 115b corresponding to each induction heating coil 115a may not be properly heated.

[0073] Therefore, in order to suppress the interference of this induced magnetic field M, a magnetic shield 118 that reflects and absorbs the induced magnetic field M can also be provided around the induction heating coil 115a. The magnetic shield 118 is preferably a plate-shaped member with a relative permeability μ > 1, such as stainless steel.

[0074] FIG11 is an explanatory diagram showing an example of the arrangement of the magnetic shield 118. As shown in FIG11, the magnetic shield 118 is formed along the side wall of the recess 113c of the base 113, and is at least higher than the induction heating coil 115a in the height direction. In other words, the magnetic shield 118 is configured such that its upper end position is at least higher than the upper end position of the induction heating coil 115a. In this way, leakage of the induced magnetic field M released from the induction heating coil 115a into the adjacent direction can be suppressed, thereby suppressing the interference of the induced magnetic field M and properly heating the magnetic body 115b (substrate W).

[0075] Furthermore, as shown in FIG12, the magnetic shield 118 may also 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, the release of the induced magnetic field M from the induction heating coil 115a downwards can be suppressed, and the dielectric heating of the conductive material provided below the electrostatic clamp 114 can be suppressed. In addition, a portion of the induced magnetic field M released downwards from the induction heating coil 115a will be reflected upwards (to the magnetic body 115b side). In this way, the directionality of the induced magnetic field M to the magnetic body 115b side can be improved, thereby improving the heating efficiency of the magnetic body 115b (substrate W).

[0076] Furthermore, in the embodiment, a magnetic shield 118 is provided on the side and / or below the induction heating coil 115a, which specifically improves the directionality of the induced magnetic field M above. However, for example, if it is desired to improve the directionality of the induced magnetic field M in other directions, the position of the magnetic shield 118 can also be appropriately changed.

[0077] Furthermore, in the above embodiments, as shown in FIG7, the heating mechanism 115 is constructed by arranging a plurality of induction heating coils 115a and magnetic bodies 115b in parallel in the surface of the substrate support 11, but the construction of the heating mechanism 115 is not limited to this.

[0078] Specifically, for example, as shown in FIG13, only one induction heating coil 115a and magnetic body 115b can be configured to heat the entire surface of the substrate W. In this case, since there is no need to connect the induction heating coil 115a and magnetic body 115b by means of power cables, the RF cutoff filter can be omitted, and the space occupied under the substrate support 11 (electrostatic clamp 114) can be suppressed. Furthermore, since the connection by means of power cables is omitted, the radio frequency applied from the RF power supply 31 to the substrate support 11 can be suppressed as noise components from entering the wiring system of the heating mechanism 115. However, when there is only one induction heating coil 115a and magnetic body 115b provided in the surface of the substrate support 11, it is not possible to control the in-plane temperature distribution of the substrate W for each temperature-controlled area as described above. From this perspective, it is desirable to arrange a plurality, if possible, multiple induction heating coils 115a and magnetic bodies 115b in parallel within the plane of the substrate support 11.

[0079] Furthermore, as described above, since the power supply cable is omitted in this embodiment, even without the RF cutoff filter, the entry of plasma-induced radio frequency (RF) noise into the wiring system of the heating mechanism 115 can be suppressed. However, even with the RF cutoff filter omitted, although the entry of plasma-induced RF noise can be suppressed, noise due to parasitic capacitance may still enter the wiring system of the heating mechanism 115. Therefore, a filter (not shown) for removing "noise due to this parasitic capacitance" can also be provided in the substrate support 11.

[0080] Furthermore, in the above embodiments, as shown in FIG2 or FIG4, a plurality of magnetic bodies 115b are arranged in a one-to-one correspondence with a plurality of induction heating coils 115a within the surface of the substrate support 11. In other words, the same number of induction heating coils 115a and magnetic bodies 115b are provided within the surface of the substrate support 11, but the number of each induction heating coil 115a and magnetic body 115b is not limited to this.

[0081] Specifically, for example, as shown in FIG14, a magnetic body 115b can also be inductively heated by a plurality of (two in the example shown) induction heating coils 115a. In this way, the number of magnetic bodies 115b disposed inside the substrate support 11 can be reduced, and the cost associated with the installation of the heating mechanism 115 can be reduced.

[0082] Furthermore, in the above embodiments, the induction heating coil 115a is formed by a circular coil member in top view, and the magnetic body 115b is formed by a rectangular plate member in top view. The shapes of the induction heating coil 115a and the magnetic body 115b are not limited to these shapes, as long as the magnetic body 115b can be heated by induction heating. That is, for example, the induction heating coil 115a can also be formed as a rectangle in top view, or it can be constructed by a plate member. Similarly, the magnetic body 115b can also be formed as a circle in top view, or it can be constructed by a coil member. Furthermore, the shape of the recess 113c formed on the top surface of the base 113 is not particularly limited, and can be appropriately modified in order to arrange the induction heating coil 115a inside.

[0083] For example, the heating mechanism 115 (induction heating coil 115a and magnetic body 115b) can also be arranged concentrically with the substrate support 11 when viewed from above. In this case, for example, as shown in FIG15, the arrangement can be determined in such a way that the areas of the temperature-adjusting regions performed by each heating mechanism 115 are approximately equal. For example, in the case of having a temperature-adjusting region that is particularly finely controlled (the radial outer side of the substrate W in the illustrated example), as shown in FIG16, the area of ​​each temperature-adjusting region can also be varied.

[0084] Thus, the induction heating coil 115a and the magnetic body 115b can be constructed in any shape, but from the viewpoint that the in-plane temperature of the electrostatic chuck 114 (substrate W) can be adjusted evenly, the shape of the induction heating coil 115a and the magnetic body 115b is expected to be a shape that can evenly cover the entire surface of the electrostatic chuck 114 (substrate W) (e.g., rectangular arrangement or honeycomb arrangement).

[0085] Furthermore, in the above embodiments, the example described is that the base 113 of the constituent body member 111 of the substrate support 11 and the electrostatic clamp 114 are directly overlapped. However, as shown in FIG17, a heat insulation layer In can also be formed between the base 113 and the electrostatic clamp 114. For example, as shown in FIG17, the heat insulation layer In can also be formed by "a vacuum heat insulation space formed by providing a sealing member S between the base 113 and the electrostatic clamp 114". Alternatively, any heat insulation member (not shown) can be provided between the base 113 and the electrostatic clamp 114.

[0086] Thus, by forming a heat insulation layer In on the body member 111 of the substrate support 11, thermal separation is achieved between the base 113 and the electrostatic chuck 114. This suppresses heat transfer between the electrostatic chuck 114 and the base 113 due to the temperature rise caused by induction heating, and the electrostatic chuck 114 (substrate W) can be heated more effectively by means of the magnetic body 115b.

[0087] Furthermore, as shown in FIG17, when the insulation layer In is constructed by a vacuum insulation space, a heat transfer fluid (e.g., brine or gas) can also circulate in the vacuum insulation space. In other words, a "fluid supply section (not shown) for supplying heat transfer fluid to the vacuum insulation space" and a "fluid discharge section (not shown) for discharging heat transfer fluid from the vacuum insulation space" can also be connected in the vacuum insulation space.

[0088] In this case, for example, when no heat transfer fluid flows through the vacuum insulation space (the insulation layer In is in a truly empty state), the base 113 and the electrostatic chuck 114 can be thermally separated, so that the electrostatic chuck 114 (substrate W) can be effectively heated by the heating of the magnetic body 115b. On the other hand, for example, when a heat transfer fluid flows through the vacuum insulation space, the base 113 and the electrostatic chuck 114 are thermally connected by the heat transfer fluid. That is, heat is transferred from the heated electrostatic chuck 114 to the base 113 through the heat transfer fluid, thereby cooling the electrostatic chuck 114. Since the configuration allows the heat transfer fluid to flow through the vacuum insulation space, by controlling the flow of the heat transfer fluid, in addition to heating for temperature adjustment of the electrostatic chuck 114, cooling can also be performed appropriately. In this way, the surface temperature of the electrostatic chuck 114 (the temperature of the substrate W) can be adjusted more appropriately, that is, the substrate W can be subjected to plasma treatment more appropriately.

[0089] It should be understood that all contents of the embodiments disclosed herein are merely illustrative and not limiting. The above embodiments can be omitted, replaced, or modified in various forms without departing from the scope and spirit of the appended patent application. [Simplified Explanation of the Diagram]

[0008] FIG1 is a longitudinal cross-sectional view showing an example of the configuration of a plasma processing system according to an embodiment of the present invention. FIG2 is a longitudinal cross-sectional view showing an example of the configuration of a substrate support according to an embodiment of the present invention. FIG3 is an explanatory diagram showing the operating principle of the heating mechanism. FIG4 is a longitudinal cross-sectional view showing an example of the configuration of a substrate support according to another embodiment. FIG5 is a schematic cross-sectional view showing an example of the configuration of the heating mechanism. FIG6 is a schematic cross-sectional view showing another example of the configuration of the heating mechanism. FIG7 is a schematic cross-sectional view showing an example of the configuration of the heating mechanism relative to the substrate support. FIG8 is a longitudinal cross-sectional view showing another example of the configuration of the heating mechanism. FIG9 is an explanatory diagram showing an example of the operation of the heating mechanism shown in FIG8. FIG10 is a longitudinal cross-sectional view showing an example of the configuration of a substrate support according to another embodiment. FIG11 is a longitudinal cross-sectional view showing another example of the configuration of the heating mechanism. FIG12 is a longitudinal cross-sectional view showing another example of the configuration of the heating mechanism. Figure 13 is a longitudinal cross-sectional view showing an example of the configuration of a substrate support according to another embodiment. Figure 14 is a longitudinal cross-sectional view showing an example of the configuration of a heating mechanism. Figure 15 is a schematic cross-sectional view showing an example of the configuration of a heating mechanism. Figure 16 is a schematic cross-sectional view showing an example of the configuration of a heating mechanism. Figure 17 is a longitudinal cross-sectional view showing an example of the configuration of a substrate support according to another embodiment.

Claims

1. A lower electrode mechanism for plasma processing, comprising: a base portion to which radio frequency power is applied during plasma processing; a dielectric portion disposed on the top surface of the base portion; and an induction heating mechanism; the induction heating mechanism comprising: an induction heating element heated by an induction magnetic field; and a magnetic field generating portion disposed inside the base portion and generating the induction magnetic field; the base portion comprising: a body member composed of a non-magnetic conductive member; and a cover member composed of a non-magnetic conductive member, disposed on the top surface of the body member, and having a recess formed on the bottom surface to house the magnetic field generating portion therein; the cover member allows the induction magnetic field generated from the magnetic field generating portion to be transmitted.

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

3. The lower electrode mechanism as described in claim 1 or 2, wherein, The main body component and the cover component are integrally formed.

4. The lower electrode mechanism as described in claim 1 or 2, wherein, The induction heating system is located inside the dielectric part.

5. The lower electrode mechanism as described in claim 1 or 2, wherein, When viewed from above, at least a portion of the inductive heating element is configured to overlap with the magnetic field generating part.

6. The lower electrode mechanism as described in claim 5, wherein, When viewed from above, the entire surface of the induction heating element is arranged to overlap with the magnetic field generating part.

7. The lower electrode mechanism as described in claim 1 or 2, wherein, The induction heating system is formed by plate components or coil components.

8. The lower electrode mechanism as described in claim 1 or 2, wherein, The induction heating system consists of at least one of the following: an iron-containing material including any one of carbon steel, ferrosilicon, stainless steel, high magnetic permeability alloy or ferromagnetic granules, or aluminum, tungsten, tin, titanium, carbon, silicon or silicon carbide.

9. The lower electrode mechanism as described in claim 1 or 2, wherein, The dielectric part is composed of non-magnetic dielectric components.

10. The lower electrode mechanism as described in claim 1 or 2, wherein, The induction heating mechanism heats at least the dielectric portion; the induction heating mechanism includes a plurality of induction heating elements and a plurality of magnetic field generating units; the induction heating mechanism can independently heat the dielectric portion for each of a plurality of pre-set temperature control zones.

11. The lower electrode mechanism as described in claim 10, wherein, In this induction heating mechanism, the same number of induction heating elements and magnetic field generating parts are provided in such a way that one induction heating element corresponds to one magnetic field generating part.

12. The lower electrode mechanism as described in claim 10, wherein, In this induction heating mechanism, a plurality of magnetic field generating units are configured to correspond to one induction heating element.

13. The lower electrode mechanism as described in claim 1 or 2, wherein, The magnetic shield that suppresses the transmission of the induced magnetic field, when viewed from above, is configured to surround the magnetic field generating part.

14. The lower electrode mechanism as described in claim 1 or 2, wherein, The magnetic shield that suppresses the transmission of the induced magnetic field is located at the lower part of the magnetic field generating part.

15. The lower electrode mechanism as described in claim 13, wherein, The magnetic shielding system is composed of components with a relative permeability greater than 1.

16. The lower electrode mechanism as described in claim 1 or 2 further includes: a driving mechanism that brings a portion of the magnetic field generating portion closer to or further away from the inductive heating element.

17. A plasma processing apparatus for processing a substrate, comprising: a plasma processing chamber defining a processing space for the substrate; a lower electrode mechanism as described in claim 10, disposed inside the processing space; a gas supply unit supplying processing gas to the processing space; and a plasma generation unit supplying radio frequency power to the lower electrode mechanism, thereby generating plasma in the processing space by means of the processing gas.

18. A substrate processing method comprising processing a substrate in a plasma processing apparatus; the plasma processing apparatus comprising: a plasma processing chamber defining a processing space for the substrate; a lower electrode mechanism disposed within the processing space; a gas supply unit supplying processing gas to the processing space; and a plasma generation unit supplying radio frequency power to the lower electrode mechanism, thereby generating plasma in the processing space by means of the processing gas; the lower electrode mechanism comprising: a base portion subjected to radio frequency power during substrate processing; an electrostatic chuck disposed on the top surface of the base portion and having a support surface for the substrate on its top surface; an induction heating element heated by an induction magnetic field; and a magnetic field generation unit disposed within the base portion and generating the induction magnetic field; the substrate processing method comprising the following steps: The steps include: generating an induced magnetic field by supplying current to the magnetic field generating unit, and adjusting the temperature of the substrate supported by the lower electrode mechanism by the induced magnetic field; and generating plasma in the processing space by supplying radio frequency power to the lower electrode mechanism after supplying the processing gas into the interior of the plasma processing chamber.

19. The substrate processing method as described in claim 18, wherein, In the step of adjusting the temperature of the substrate, the amount of current supplied to the magnetic field generating part is adjusted based on the difference between the measured temperature of the substrate supported by the lower electrode mechanism and the target temperature of the substrate.

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