Substrate support and substrate processing apparatus

Abstract

Provided is a substrate support arranged inside a plasma processing chamber, the substrate support comprising a base that is electrically connected to at least one power supply, a first dielectric part that is arranged on the base and that has a substrate support surface, and a second dielectric part that is arranged on the base so as to surround the first dielectric part and that has a ring support surface, the first dielectric part having incorporated therein a first heat-conducting-gas diffusion space, a first electrode arranged above the first heat-conducting-gas diffusion space, and an electroconductive section that is electrically connected to the first electrode and to the base, and the second dielectric part having incorporated therein a second heat-conducting-gas diffusion space, and a second electrode that is arranged above the second heat-conducting-gas diffusion space and that is electrically connected to a power supply for outputting a voltage in common with the base.

Description

Technical Field

[0001] The present disclosure relates to a substrate support and a substrate processing apparatus.

Background Art

[0002] Patent Document 1 discloses a mounting table having a substrate mounting surface on which a substrate is placed and an edge ring mounting surface on which an edge ring is placed. A gas supply pipe is provided inside the mounting table described in Patent Document 1, and a heat transfer gas such as helium gas is supplied between the back surface of the substrate and the substrate mounting surface and between the back surface of the edge ring and the edge ring mounting surface through this gas supply pipe.

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 suppresses the occurrence of abnormal discharge in a gas diffusion space formed inside a substrate support portion during plasma processing of a substrate.

Means for Solving the Problems

[0005] One aspect of the present disclosure is a substrate support comprising: a base electrically connected to at least one power source; a first dielectric portion disposed on the base and having a substrate support surface; and a second dielectric portion disposed on the base so as to surround the first dielectric portion and having a ring support surface, wherein the first dielectric portion has internally a first heat transfer gas diffusion space for supplying heat transfer gas toward the substrate support surface; a first electrode disposed above the first heat transfer gas diffusion space so as to overlap vertically with at least a portion of the first heat transfer gas diffusion space; and a conductive portion for electrically connecting the first electrode and the base; and the second dielectric portion has internally a second heat transfer gas diffusion space for supplying heat transfer gas toward the ring support surface; and a second electrode disposed above the second heat transfer gas diffusion space so as to overlap vertically with at least a portion of the second heat transfer gas diffusion space and is electrically connected to a power source that outputs a voltage common to the base. [Effects of the Invention]

[0006] According to this disclosure, when performing plasma treatment on a substrate, it is possible to suppress the occurrence of abnormal discharge in the gas diffusion space formed inside the substrate support portion. [Brief explanation of the drawing]

[0007] [Figure 1] This is a diagram illustrating an example configuration of a plasma processing system. [Figure 2] This is a block diagram of a computer that can implement various embodiments. [Figure 3] This is a diagram illustrating an example configuration of a capacitively coupled plasma processing apparatus. [Figure 4] This is a cross-sectional view showing a schematic configuration of the substrate support part according to the embodiment. [Figure 5] This is an explanatory diagram of the capacitance in a conventional substrate support structure. [Figure 6] This is an explanatory diagram of the capacitance in the substrate support portion according to the embodiment. [Modes for carrying out the invention]

[0008] In the semiconductor device manufacturing process, various plasma treatments such as etching, film deposition, and diffusion are performed on a semiconductor substrate (hereinafter simply referred to as "substrate") supported by a substrate support in a chamber. In these plasma treatments, it is important to appropriately control the substrate temperature during processing in order to obtain processing results with high in-plane uniformity for the substrate being processed.

[0009] The substrate temperature during plasma processing is controlled, for example, by creating a gas supply space inside the substrate support that supports the substrate to be processed, and supplying heat transfer gas between the back surface of the substrate and the substrate support surface.

[0010] However, when a gas supply space is formed inside the substrate support in this manner, a potential difference may be generated within the gas supply space when high-frequency power is applied to the substrate support during plasma processing. As a result, there is a risk that abnormal discharge may occur within the gas supply space.

[0011] The technology described herein has been developed in view of the above circumstances and suppresses the occurrence of abnormal discharge in the gas diffusion space formed inside the substrate support during plasma treatment of the substrate. Hereinafter, the substrate processing apparatus and substrate support according to this embodiment will be described with reference to the drawings. In this specification and drawings, elements having substantially the same functional configuration are denoted by the same reference numerals, and redundant explanations will be omitted.

[0012] <Plasma Treatment System> First, a plasma processing system according to one embodiment will be described with reference to Figure 1. Figure 1 is a diagram illustrating an example of the configuration of a plasma processing system.

[0013] In one embodiment, the plasma processing system includes a plasma processing apparatus 1 and a control unit 2. The plasma processing system is an example of a substrate processing system, and the plasma processing apparatus 1 is an example of a substrate processing apparatus. The plasma processing apparatus 1 includes a plasma processing chamber 10, a substrate support section 11, and a plasma generation section 12. The plasma processing chamber 10 has a plasma processing space. The plasma processing chamber 10 also has at least one gas supply port for supplying at least one processing gas to the plasma processing space, and at least one gas outlet for discharging gas from the plasma processing space. The gas supply port is connected to a gas supply section 20, which will be described later, and the gas outlet is connected to an exhaust system 40, which will be described later. The substrate support section 11 is located in the plasma processing space and has a substrate support surface for supporting a substrate and a ring support surface for supporting an edge ring.

[0014] The plasma generation unit 12 is configured to generate plasma from at least one processing gas supplied into the plasma processing space. The plasma formed in the plasma processing space may be a capacitively coupled plasma (CCP), an inductively coupled plasma (ICP), an electron-cyclotron-resonance plasma (ECR), a helicon wave-excited plasma (HWP), or a surface wave plasma (SWP), etc. Various types of plasma generation units, including an AC (Alternating Current) plasma generation unit and a DC (Direct Current) plasma generation unit, may also be used. In one embodiment, the AC signal (AC power) used in the AC plasma generation unit has a frequency in the range of 100 kHz to 10 GHz. Therefore, the AC signal includes an RF (Radio Frequency) signal and a microwave signal. In one embodiment, the RF signal has a frequency in the range of 100 kHz to 150 MHz.

[0015] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform various processes described herein. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to perform 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 a processing unit 2a1, a storage unit 2a2, and a communication interface 2a3. The control unit 2 is implemented, for example, by a computer 2a. The processing unit 2a1 may be configured to perform various control operations by reading a program from the storage unit 2a2 and executing the read program. This program may be stored in the storage unit 2a2 in advance, or it may be obtained via a medium when needed. The obtained program is stored in the storage unit 2a2 and read from the storage unit 2a2 and executed by the processing unit 2a1. The medium may be various storage media readable by the computer 2a, or it may be a communication line connected to the communication interface 2a3. The processing unit 2a1 may be a CPU (Central Processing Unit). The memory unit 2a2 may 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 may communicate with the plasma processing device 1 via a communication line such as a LAN (Local Area Network). Furthermore, the storage medium may be temporary or permanent.

[0016] <Control unit or control circuit> Figure 2 is a block diagram of a computer that may implement the various embodiments described herein. The control embodiments of the Disclosure may be embodied as a system, method, and / or computer program product. The computer program product includes a computer-readable storage medium on which computer-readable program instructions are recorded, and one or more processors may execute embodiments of the embodiments.

[0017] A computer-readable storage medium may be a tangible device capable of storing instructions used by an instruction execution unit (processor). Examples of computer-readable storage media include, but are not limited to, electronic storage devices, magnetic storage devices, optical storage devices, electromagnetic storage devices, semiconductor storage devices, or any suitable combination thereof. A non-exhaustive list of more specific examples of computer-readable storage media (and suitable combinations) includes: flexible disks, hard disks, solid-state drives (SSDs), random-access memory (RAM), read-only memory (ROM), programmable read-only memory (EPROM or flash), static random-access memory (SRAM), compact disks (CDs or CD-ROMs), digital general-purpose disks (DVDs), memory cards, or sticks. The computer-readable storage media used in this disclosure should not be interpreted as themselves being transient signals, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through waveguides or other transmission media (e.g., light pulses passing through optical fiber cables), or electrical signals passing through wires.

[0018] The computer-readable program instructions described in this disclosure can be downloaded from a computer-readable storage medium or from an external computer or external storage device to a suitable computing device or processing device via a global network (i.e., the Internet), a local area network, a wide area network, and / or a wireless network. The network may include copper wire, optical communication fiber, wireless transmission, routers, firewalls, switches, gateway computers, edge servers. The network adapter card or network interface of each computing device or processing device may receive the computer-readable program instructions from the network and transfer them to store the computer-readable program instructions in a computer-readable storage medium within the computing device or processing device.

[0019] Computer-readable program instructions for performing the operations of the present disclosure include machine language instructions and / or microcode and can be compiled or interpreted from source code written in any combination of one or more programming languages including assembly language, Basic, Fortran, Java, Python, R, C, C++, C#, or similar programming languages. The computer-readable program instructions may be executed entirely on a user's personal computer, notebook computer, tablet, or smartphone, or entirely on a remote computer or computer server, or on any combination of these computing devices. The remote computer or computer server can be connected to the user's device or devices via a computer network including a local area network, wide area network, or global network (Internet). In some embodiments, an electronic circuit uses information from computer-readable program instructions, including, for example, programmable logic circuits, field programmable gate arrays (FPGAs), or programmable logic arrays (PLAs), to execute the computer-readable program instructions to configure or customize the electronic circuit and perform aspects of the present disclosure.

[0020] Aspects of the present disclosure will be described with reference to the flow diagrams and block diagrams of methods, apparatus (systems), and computer program products according to embodiments of the disclosure. Those skilled in the art will understand that each block of the flow diagrams and block diagrams, and combinations of blocks in the flow diagrams and block diagrams, can be implemented by computer-readable program instructions.

[0021] Computer-readable program instructions capable of implementing the systems and methods described herein may be provided to one or more processors (and / or one or more cores within a processor) of a general-purpose computer, a special-purpose computer, or other programmable device. These computer-readable program instructions may be stored in a computer-readable storage medium that can instruct a computer, a programmable device, and / or other device to function in a particular way, in which case the computer-readable storage medium storing the instructions is a product containing instructions that implement the aspects of the functionality specified in the flowcharts and block diagrams of this disclosure.

[0022] Furthermore, computer-readable program instructions may be loaded into a computer, another programmable device, or other device, and instructions executed on the computer, another programmable device, or other device may be caused to perform a series of operational steps to implement the functions specified in the flowcharts and block diagrams of this disclosure, thereby generating a computer implementation process.

[0023] Figure 2 is a functional block diagram showing a networked system 800 of one or more networked computers and servers. In one embodiment, the hardware and software environment shown in Figure 2 may provide an exemplary platform for implementing the software and / or methods relating to this disclosure.

[0024] As shown in Figure 2, the networked system 800 may include, but is not limited to, a computer 805, a network 810, a remote computer 815, a web server 820, a cloud storage server 825, and a computer server 830. In some embodiments, multiple instances of one or more functional blocks shown in Figure 2 may be employed.

[0025] Additional details of computer 805 are shown in Figure 2. The functional blocks shown within computer 805 are provided only to establish exemplary functionality and are not intended to be exhaustive. Details are not provided for the remote computer 815, web server 820, cloud storage server 825, and computer server 830, but these other computers and devices may have similar functionality to that shown for computer 805.

[0026] Computer 805 can be a personal computer (PC), desktop computer, laptop computer, tablet computer, netbook computer, personal digital assistant (PDA), smartphone, or any other programmable electronic device capable of communicating with other devices on network 810.

[0027] Computer 805 may include a processor 835, a bus 837, memory 840, non-volatile storage 845, a network interface 850, a peripheral interface 855, and a display interface 865. Each of these functions may, in some embodiments, be implemented as an individual electronic subsystem (an integrated circuit chip or a combination of a chip and associated devices), or, in other embodiments, a combination of some functions, on a single chip (sometimes called a chip-on-a-system or SoC).

[0028] The Processor 835 may be one or more single or multi-chip microprocessors, such as those designed and / or manufactured by Intel Corporation, Advanced Microdevices Corporation (AMD), ARM Holdings (ARM), Apple Computer, etc. Examples of microprocessors include Intel's Celeron, Pentium, Core i3, Core i5, and Core i7; AMD's Opteron, Phenom, Athlon, Turion, and Ryzen; and ARM's Cortex-A, Cortex-R, and Cortex-M.

[0029] Bus 837 can be a proprietary standard high-speed parallel or serial peripheral interconnect bus such as ISA, PCI, PCI Express (PCI-e), or AGP.

[0030] The memory 840 and non-volatile storage 845 can be computer-readable storage media. The memory 840 may include any suitable volatile storage device, such as dynamic random access memory (DRAM) and static random access memory (SRAM). The non-volatile storage 845 may include one or more of the following: flexible disks, hard disks, solid-state drives (SSDs), read-only memory (ROM), programmable read-only memory (EPROM or Flash), compact disks (CD or CD-ROM), digital general-purpose disks (DVDs), and memory cards or sticks.

[0031] The program 848 may be stored in non-volatile storage 845 and may be a set of machine-readable instructions and / or data used to create, manage, and control certain software functions described in detail elsewhere in this disclosure and shown in the drawings. In some embodiments, memory 840 may be considerably faster than non-volatile storage 845. In such embodiments, the program 848 may be transferred from non-volatile storage 845 to memory 840 before being executed by processor 835.

[0032] Computer 805 can communicate and interact with other computers via the network interface 850 and the network 810. The network 810 may include, for example, a local area network (LAN), a wide area network (WAN) such as the Internet, or a combination of both, and may be wired, wireless, or fiber optic connections. Generally, the network 810 can be any combination of connections and protocols that support communication between two or more computers and associated devices.

[0033] The peripheral interface 855 may enable data input and output with other devices that may be locally connected to the computer 805. For example, the peripheral interface 855 may provide a connection to an external device 860. The external device 860 may include devices such as a keyboard, mouse, keypad, touchscreen, and / or other suitable input devices. The external device 860 may also include portable computer-readable storage media such as a thumb drive, portable optical or magnetic disk, and memory card. The software and data used in embodiments of this disclosure may be stored, for example, in a program 848, a portable computer-readable storage medium, etc. In such embodiments, the software may be loaded into non-volatile storage 845, or, instead, directly into memory 840 via the peripheral interface 855. The peripheral interface 855 may connect to the external device 860 using industry standard connections such as RS-232 or Universal Serial Bus (USB).

[0034] The display interface 865 may connect the computer 805 to the display 870. In some embodiments, the display 870 may be used to present a command line or a graphical user interface to the user of the computer 805. The display interface 865 can connect to the display 870 using one or more proprietary connections or industry standard connections such as VGA, DVI, DisplayPort, or HDMI®.

[0035] As described above, the network interface 850 provides communication with other computing systems and storage systems or devices outside of computer 805. The software programs and data described herein may be downloaded to non-volatile storage 845 via the network interface 850 and network 810 from, for example, a remote computer 815, a web server 820, a cloud storage server 825, and a computer server 830. Furthermore, the systems and methods described herein may be executed by one or more computers connected to computer 805 via the network interface 850 and network 810. For example, in some embodiments, the systems and methods described herein may be executed by a combination of a remote computer 815, a computer server 830, or interconnected computers on network 810.

[0036] Data, datasets, and / or databases used in embodiments of the systems and methods described herein may be stored or downloaded from a remote computer 815, a web server 820, a cloud storage server 825, and a computer server 830.

[0037] <Plasma Processing Equipment> Next, as an example of the plasma processing apparatus 1 described above, a configuration example of a capacitively coupled plasma processing apparatus 1 will be explained. Figure 3 is a diagram illustrating a configuration example of the plasma processing apparatus 1.

[0038] 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 unit 11 as an example of a substrate support and a gas introduction unit. The substrate support unit 11 is located inside 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 located above the substrate support unit 11. In one embodiment, the shower 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 shower head 13, the side walls 10a of the plasma processing chamber 10, and the substrate support unit 11. The plasma processing chamber 10 is grounded. The shower head 13 and the substrate support unit 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0039] The substrate support portion 11 includes a main body portion 110 and a ring assembly 120. The main body portion 110 has a central region 110a for supporting the substrate W and an annular region 110b for supporting the ring assembly 120. A wafer is an example of the substrate W. The annular region 110b of the main body portion 110 surrounds the central region 110a of the main body portion 110 in a plan view. The substrate W is placed on the central region 110a of the main body portion 110, and the ring assembly 120 is placed on the annular region 110b of the main body portion 110 so as to surround the substrate W on the central region 110a of the main body portion 110. Therefore, the central region 110a is also called the substrate support surface for supporting the substrate W, and the annular region 110b is also called the ring support surface for supporting the ring assembly 120.

[0040] In one embodiment, the main body 110 includes a conductive base 111, an electrostatic chuck 112, and an annular electrostatic chuck 113.

[0041] The conductive base 111 includes a conductive material such as aluminum and has a substantially disc shape. The conductive material of the conductive base 111 can function as a lower electrode. The electrostatic chuck 112 is placed on a conductive base 111. The electrostatic chuck 112 includes a ceramic member 112a, a plurality of electrodes 114 placed within the ceramic member 112a, and a heat transfer gas supply section 115 formed within the ceramic member 112a (see Figure 4). The ceramic member 112a has a central region 110a. The annular electrostatic chuck 113 is positioned on the conductive base 111 so as to surround the electrostatic chuck 112. The annular electrostatic chuck 113 includes a ceramic member 113a, a plurality of electrodes 116 arranged within the ceramic member 113a, and a heat transfer gas supply section 117 formed within the ceramic member 113a (see Figure 4). The ceramic member 113a has an annular region 110b. The annular electrostatic chuck 113 may be formed integrally with the electrostatic chuck 112 on the conductive base 111 as shown in the figure, or it may be formed independently (separated).

[0042] At least one RF / DC electrode may be placed within the ceramic members 112a and 113a, which is coupled to the RF power supply 31 and / or DC power supply 32 described later. The at least one RF / DC electrode may correspond to the multiple electrodes 114 and 116 described above. In this case, at least one RF / DC electrode functions as a lower electrode. When a bias RF signal and / or DC signal described later is supplied to at least one RF / DC electrode, the RF / DC electrode is also called a bias electrode. The conductive member of the conductive base 111 and at least one RF / DC electrode may function as multiple lower electrodes. Also, an electrostatic electrode may function as a lower electrode. Therefore, the substrate support portion 11 includes at least one lower electrode.

[0043] The ring assembly 120 includes one or more annular members. In one embodiment, the one or more annular members include one or more edge rings. Also, the one or more annular members may include at least one covering ring. The edge rings are formed of a conductive or insulating material, and the covering rings are formed of an insulating material. The ring assembly 120 may be placed on the annular electrostatic chuck 113, or on both the electrostatic chuck 112 and the annular electrostatic chuck 113.

[0044] The substrate support section 11 may also include a temperature control module configured to adjust at least one of the electrostatic chuck 112, the annular electrostatic chuck 113, the ring assembly 120, and the substrate W to a target temperature. The temperature control module may include a heater, a heat transfer medium, a flow path 111a, or a combination thereof. A heat transfer fluid such as brine or gas flows through the flow path 111a. In one embodiment, the flow path 111a is formed within the conductive base 111, and one or more heaters are arranged within the ceramic members 112a and 113a of the electrostatic chuck 112 and the annular electrostatic chuck 113. The configuration of the temperature control module is not limited to this, and it is sufficient if it is configured to adjust the temperature of at least one of the electrostatic chuck 112, the annular electrostatic chuck 113, the ring assembly 120, and the substrate W.

[0045] The detailed configuration of the substrate support section 11 will be described later.

[0046] The showerhead 13 is configured to introduce at least one processing 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 inlet ports 13c. The processing gas supplied to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s through the plurality of gas inlet ports 13c. The showerhead 13 also includes at least one upper electrode. In addition to the showerhead 13, the gas introduction unit may also include one or more side gas injectors (SGIs) attached to one or more openings formed in the side wall 10a.

[0047] 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 processing gas to the shower head 13 from a corresponding gas source 21 via a corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Furthermore, the gas supply unit 20 may include at least one flow modulation device that modulates or pulses the flow rate of at least one processing gas.

[0048] 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) to at least one lower electrode and / or at least one upper electrode. This causes plasma to be 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 the plasma generation unit 12. In addition, by supplying a bias RF signal to at least one lower electrode, a bias potential is generated on the substrate W, and ions in the formed plasma can be drawn into the substrate W.

[0049] 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 at least one lower electrode and / or at least one 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 10 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. One or more generated source RF signals are supplied to at least one lower electrode and / or at least one upper electrode.

[0050] The second RF generation unit 31b is coupled to at least one lower electrode via at least one impedance matching circuit and is configured to generate a bias RF signal (bias RF power). The frequency of the bias RF signal may be the same as or different from the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency lower than the frequency of the source RF signal. In one embodiment, the bias RF signal has a frequency in the range of 100 kHz to 60 MHz. In one embodiment, the second RF generation unit 31b may be configured to generate a plurality of bias RF signals having different frequencies. One or more generated bias RF signals are supplied to at least one lower electrode. In various embodiments, at least one of the source RF signal and the bias RF signal may be pulsed.

[0051] The power supply 30 may also 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 at least one lower electrode and configured to generate a first DC signal. The generated first DC signal is applied to at least one lower electrode. In one embodiment, the second DC generation unit 32b is connected to at least one upper electrode and configured to generate a second DC signal. The generated second DC signal is applied to at least one upper electrode.

[0052] In various embodiments, the first and second DC signals may be pulsed. In this case, a sequence of voltage pulses is applied to at least one lower electrode and / or at least one upper electrode. The voltage pulses may have a rectangular, trapezoidal, triangular, or a combination thereof pulse waveform. In one embodiment, a waveform generation unit for generating a sequence of voltage pulses from the DC signal is connected between the first DC generation unit 32a and at least one lower electrode. Thus, the first DC generation unit 32a and the waveform generation unit constitute a voltage pulse generation unit. When the second DC generation unit 32b and the waveform generation unit constitute a voltage pulse generation unit, the voltage pulse generation unit is connected to at least one upper electrode. The voltage pulses may have positive or negative polarity. The sequence of voltage pulses may also include one or more positive voltage pulses and one or more negative voltage pulses within one period. The first and second DC generation units 32a and 32b may be provided in addition to the RF power supply 31, and the first DC generation unit 32a may be provided in place of the second RF generation unit 31b.

[0053] The exhaust system 40 may be connected to, for example, a gas outlet 10e located at the bottom of the plasma processing chamber 10. The exhaust system 40 may include a pressure regulating valve and a vacuum pump. The pressure regulating valve regulates the pressure in the plasma processing space 10s. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0054] <Substrate support section> Next, an example of the detailed configuration of the substrate support section 11 as a substrate support according to this embodiment will be described. Figure 4 is a cross-sectional view showing a schematic configuration of the substrate support section 11. Note that in Figure 4, the substrate W supported by the electrostatic chuck 112, the ring assembly 120 supported by the annular electrostatic chuck 113, and the flow path 111a within the conductive base 111 are omitted from the illustration.

[0055] As described above, the substrate support portion 11 includes a main body portion 110 and a ring assembly 120. The main body portion 110 includes a conductive base 111, an electrostatic chuck 112, and an annular electrostatic chuck 113.

[0056] The conductive base 111 includes a conductive material such as aluminum and has a substantially disc shape. An electrostatic chuck 112 and an annular electrostatic chuck 113 are placed on the conductive base 111. In one example, the electrostatic chuck 112 and the annular electrostatic chuck 113 are joined to the conductive base 111 via a bonding layer (not shown). The bonding layer is formed of a material that has plasma resistance and heat resistance, such as an acrylic resin, silicone resin, or epoxy resin. As shown in Figure 4, the conductive base 111 is electrically connected to a high-frequency power supply RFS that generates the source RF signal and a bias power supply S2, described later, that generates the bias signal for the ring assembly 120. The power supply 30 described above may be used as the high-frequency power supply RFS.

[0057] The electrostatic chuck 112 is placed on the conductive base 111 as described above. The electrostatic chuck 112 includes a ceramic member 112a having at least one layer of insulating (dielectric) material, for example, a ceramic layer in this embodiment. The ceramic member 112a has a central region 110a on its upper surface. The annular electrostatic chuck 113 is positioned on the conductive base 111 so as to surround the electrostatic chuck 112, as described above. The annular electrostatic chuck 113 includes a ceramic member 113a having at least one layer of insulating (dielectric) material, for example, a ceramic layer in this embodiment. The ceramic member 113a has an annular region 110b on its upper surface.

[0058] The ceramic member 112a of the electrostatic chuck 112 has a greater thickness compared to the ceramic member 113a of the annular electrostatic chuck 113. In other words, the main body 110 of the substrate support portion 11 has a substantially convex cross-sectional shape in which the substrate support surface (central region 110a) is higher than the ring support surface (annular region 110b) and a protrusion is formed on the upper surface.

[0059] Inside the ceramic member 112a, which serves as the first dielectric part, are provided multiple electrodes 114, including an electrostatic electrode 114a, a bias electrode 114b, and a discharge prevention electrode 114c. The electrostatic electrode is an example of a clamp electrode. Inside the ceramic member 112a, a heat transfer gas supply section 115 is formed to supply a heat transfer gas such as helium gas (hereinafter referred to as "heat transfer gas") between the back surface of the substrate W and the central region 110a. The electrostatic chuck 112 is constructed by sandwiching the electrostatic electrode 114a, bias electrode 114b, discharge prevention electrode 114c, and heat transfer gas supply section 115 between ceramic members 112a (a pair of dielectric films made of a non-magnetic dielectric such as ceramics).

[0060] The electrostatic electrode 114a is electrically connected to the electrostatic adsorption power supply HV1 for the substrate W. By applying a voltage from the electrostatic adsorption power supply HV1 to the electrostatic electrode 114a, an electrostatic force such as Coulomb force is generated, and the substrate W is adsorbed and held in the central region 110a by the generated electrostatic force. The power supply 30 described above may be used as the electrostatic adsorption power supply HV1. The electrostatic adsorption power supply HV1 can output either a positive or negative voltage. The electrostatic adsorption power supply HV1 may be a DC power supply or an AC power supply. The electrostatic electrode 114a may be unipolar or multipolar. Furthermore, the electrostatic electrode 114a may be divided.

[0061] The bias electrode 114b is positioned below the electrostatic electrode 114a inside the ceramic member 112a. The bias electrode 114b is primarily used to draw ions to the central part of the substrate W. The bias electrode 114b can also function as a lower electrode. The bias power supply S1 for the substrate W is electrically connected to the bias electrode 114b. In one example, the bias power supply S1 outputs a negative DC pulse. The power supply 30 described above may be used as the bias power supply S1. Furthermore, the voltage applied from the bias power supply S1 is not limited to a negative DC pulse, but can be appropriately changed depending on the purpose of substrate processing in the plasma processing apparatus 1. That is, a positive voltage may be applied instead of a negative voltage, or a high-frequency AC voltage may be applied instead of a DC voltage. Also, a continuous wave may be supplied instead of a pulse wave. In addition, the bias electrode 114b may be divided.

[0062] The discharge prevention electrode 114c is positioned inside the ceramic member 112a below the bias electrode 114b and above the diffusion space 115a of the heat transfer gas supply unit 115, which will be described later. The discharge prevention electrode 114c is also positioned so as to overlap at least a portion of the diffusion space 115a, which will be described later, in the vertical direction (in a plan view), preferably with respect to the entire diffusion space 115a in a plan view. The discharge prevention electrode 114c is electrically connected to the conductive base 111 via the conductive member 114c1, and a common voltage is applied to the discharge prevention electrode 114c and the conductive base 111. As a result, a space of the same potential is formed inside the ceramic member 112a between the conductive base 111 and the discharge prevention electrode 114c in the thickness direction. The conductive member 114c1 corresponds to the "conductive part" in the technology of this disclosure.

[0063] The number of conductive members 114c1 connecting the conductive base 111 and the discharge prevention electrode 114c is not particularly limited, and multiple conductive members 114c1 may be arranged along the circumferential direction of the electrostatic chuck 112. In this case, it is desirable that the multiple conductive members 114c1 be arranged at equal intervals along the circumferential direction of the electrostatic chuck 112. The conductive members 114c1 may be vias, for example. Also, the discharge prevention electrode 114c may be divided.

[0064] The heat transfer gas supply unit 115 has a diffusion space 115a, a gas inlet 115b for supplying heat transfer gas to the diffusion space 115a, and a gas outlet 115c for discharging heat transfer gas from the diffusion space 115a. The heat transfer gas supply unit 115 supplies heat transfer gas from a heat transfer gas supply source (not shown) between the back surface of the substrate W and the central region 110a via the gas inlet 115b, the diffusion space 115a, and the gas outlet 115c in that order. The heat transfer gas is also called "backside gas". Furthermore, multiple heat transfer gas supply units 115 may be formed inside the ceramic member 112a. Alternatively, the heat transfer gas supply units 115 may be formed by embedding gas supply pipes inside the ceramic member 112a, or they may be formed as cavities by not laminating ceramics (dielectric members) in a part of the ceramic member 112a.

[0065] The first heat transfer gas diffusion space, diffusion space 115a, is formed inside the ceramic member 112a below the discharge prevention electrode 114c. More specifically, the diffusion space 115a is formed inside the ceramic member 112a between the conductive base 111 and the discharge prevention electrode 114c, i.e., in the same potential space described above. The gas inlet 115b extends downward from the diffusion space 115a to the underside of the conductive base 111. A heat transfer gas supply source (not shown) is connected to the gas inlet 115b. The gas outlet 115c is formed extending upward from the diffusion space 115a to the substrate support surface (central region 110a), which is the upper surface of the ceramic member 112a. The number of gas outlets 115c extending from the diffusion space 115a, in other words, the number of heat transfer gas discharge holes on the substrate support surface, is not particularly limited and may be formed in multiple locations along the circumferential direction of the electrostatic chuck 112.

[0066] In the substrate support portion 11 according to this embodiment, the diffusion space 115a for supplying heat transfer gas is formed in the same potential space inside the ceramic member 112a. Therefore, the generation of a potential difference inside the diffusion space 115a is suppressed, thereby preventing abnormal discharge from occurring in the diffusion space 115a during plasma processing of the substrate W.

[0067] Inside the ceramic member 113a, which serves as the second dielectric part, are provided multiple electrodes 116, namely electrostatic electrodes 116a and bias electrodes 116b. Inside the ceramic member 113a, a heat transfer gas supply section 117 is formed to supply heat transfer gas between the back surface of the ring assembly 120 and the annular region 110b. The annular electrostatic chuck 113 is constructed by sandwiching the electrostatic electrodes 116a, bias electrodes 116b, and heat transfer gas supply section 117 between ceramic members 113a (a pair of dielectric films made of a non-magnetic dielectric such as ceramics).

[0068] The electrostatic electrode 116a is electrically connected to the electrostatic adsorption power supply HV2 for the ring assembly 120. By applying a voltage from the electrostatic adsorption power supply HV2 to the electrostatic electrode 116a, an electrostatic force such as Coulomb force is generated, and the ring assembly 120 is adsorbed and held in the annular region 110b by the generated electrostatic force. The power supply 30 described above may be used as the electrostatic adsorption power supply HV2. The electrostatic adsorption power supply HV2 can output either a positive or negative voltage. The electrostatic adsorption power supply HV2 may be a DC power supply or an AC power supply. The electrostatic electrode 116a may be unipolar or multipolar. Furthermore, the electrostatic electrode 116a may be divided.

[0069] The bias electrode 116b is positioned below the electrostatic electrode 116a inside the ceramic member 113a. The bias electrode 116b is also positioned so as to overlap with at least a portion of the diffusion space 117a described later, preferably the entire diffusion space 117a in the vertical direction (in a plan view). The bias electrode 116b is mainly used to draw ions to the peripheral edge of the substrate W. The bias electrode 116b is electrically connected to the bias power supply S2 of the ring assembly 120 and the high-frequency power supply RFS described above. In other words, the power supply connected to the bias electrode 116b is the same as the power supply connected to the conductive base 111. As a result, a common voltage is applied to the conductive base 111 and the bias electrode 116b inside the ceramic member 113a, creating a space with the same potential between the conductive base 111 and the bias electrode 116b in the thickness direction. The power supply 30 described above may be used as the bias power supply S2. In one example, the bias power supply S2 may output a negative DC pulse, but the voltage applied from the bias power supply S2 can be appropriately changed depending on the purpose of substrate processing in the plasma processing apparatus 1. That is, a positive voltage may be applied instead of a negative voltage, or a high-frequency AC voltage may be applied instead of a DC voltage. A continuous wave may also be supplied instead of a pulse wave. Furthermore, the bias electrode 116b may be divided.

[0070] The heat transfer gas supply unit 117 has a diffusion space 117a, a gas inlet 117b for supplying heat transfer gas to the diffusion space 117a, and a gas outlet 117c for discharging heat transfer gas from the diffusion space 117a. The heat transfer gas supply unit 117 supplies heat transfer gas from a heat transfer gas supply source (not shown) between the back surface of the ring assembly 120 and the annular region 110b via the gas inlet 117b, the diffusion space 117a, and the gas outlet 117c in that order. Furthermore, multiple heat transfer gas supply units 117 may be formed inside the ceramic member 113a. Alternatively, the heat transfer gas supply units 117 may be formed by embedding gas supply pipes inside the ceramic member 113a, or they may be formed as cavities by not laminating ceramics (dielectric members) in a part of the ceramic member 113a.

[0071] The second heat transfer gas diffusion space, diffusion space 117a, is formed inside the ceramic member 113a below the bias electrode 116b. More specifically, the diffusion space 117a is formed inside the ceramic member 113a between the conductive base 111 and the bias electrode 116b, i.e., in the same potential space described above. The gas inlet 117b extends downward from the diffusion space 117a to the lower surface of the conductive base 111. A heat transfer gas supply source (not shown) is connected to the gas inlet 117b. The heat transfer gas supply source connected to the gas inlet 117b may be used in common with the heat transfer gas supply source connected to the heat transfer gas supply unit 115 on the electrostatic chuck 112 side, or it may be used independently. In other words, the plasma processing apparatus 1 according to this embodiment is provided with one or more heat transfer gas supply sources (not shown). The gas outlet 117c is formed extending upward from the diffusion space 117a to the ring support surface (annular region 110b), which is the upper surface of the ceramic member 113a. The number of gas outlets 117c extending from the diffusion space 117a, in other words, the number of heat transfer gas discharge holes on the ring support surface, is not particularly limited and may be formed in multiple locations along the circumferential direction of the annular electrostatic chuck 113.

[0072] In the substrate support portion 11 according to this embodiment, the diffusion space 117a for supplying heat transfer gas is formed in the same potential space inside the ceramic member 113a. Therefore, the generation of a potential difference inside the diffusion space 117a is suppressed, thereby preventing abnormal discharge from occurring in the diffusion space 117a during plasma processing of the substrate W.

[0073] According to the substrate support portion 11 of the above embodiment, in the electrostatic chuck 112, a discharge prevention electrode 114c electrically connected to the conductive base 111 is placed to form a potential space inside the ceramic member 112a. In the annular electrostatic chuck 113, a common power supply is connected to the bias electrode 116b and the conductive base 111, and a common voltage is applied to form a potential space inside the ceramic member 113a. In the substrate support portion 11 according to this embodiment, diffusion spaces 115a and 117a for supplying heat transfer gas are arranged within the same potential space formed inside the ceramic members 112a and 113a, between the back surface of the substrate W and the central region 110a, and between the back surface of the ring assembly 120 and the annular region 110b, respectively. By arranging diffusion spaces 115a and 117a in the same potential space in this manner, the generation of a potential difference within the diffusion space is suppressed, and as a result, the occurrence of abnormal discharge in the diffusion space during plasma processing of the substrate W can be suppressed.

[0074] In the above embodiment, a discharge prevention electrode 114c electrically connected to the conductive base 111 is placed in the electrostatic chuck 112 on the central region 110a side, and the bias electrode 116b in the annular electrostatic chuck 113 on the annular region 110b side is connected to a power supply common to the conductive base 111. However, the method of forming the same potential space in each is not limited. That is, for example, discharge prevention electrodes electrically connected to the conductive base 111 may be placed on both the electrostatic chuck 112 and the annular electrostatic chuck 113, or bias electrodes may be connected to a power supply common to the conductive base 111 on both the electrostatic chuck 112 and the annular electrostatic chuck 113. Alternatively, for example, the bias electrode 114b on the electrostatic chuck 112 may be connected to a power supply common to the conductive base 111, and a discharge prevention electrode electrically connected to the conductive base 111 may be placed on the annular electrostatic chuck 113.

[0075] In the above embodiments, for example, from the viewpoint of ease of molding the electrostatic chuck, the discharge prevention electrode 114c in the ceramic member 112a was placed at the same height (in the same plane) as the bias electrode 116b in the ceramic member 113a. However, the arrangement of the discharge prevention electrode 114c is not limited to this.

[0076] When the substrate W is placed on the central region 110a, capacitance is generated between the substrate W and the electrostatic electrode 114a, between the electrostatic electrode 114a and the bias electrode 114b, and between the bias electrode 114b and the discharge prevention electrode 114c. When these are combined, capacitance is generated between the substrate W and the discharge prevention electrode 114c. Since the capacitance depends on the distance between the substrate W and the discharge prevention electrode 114c, the value of the capacitance generated between the substrate W and the discharge prevention electrode 114c can be adjusted by changing the height position of the discharge prevention electrode 114c within the ceramic member 112a. In this way, by changing the height position of the discharge prevention electrode 114c within the ceramic member 112a, the capacitance ratio between the electrostatic chuck 112 on which the substrate W is placed and the annular electrostatic chuck 113 on which the ring assembly 120 is placed can be controlled. In other words, the impedance ratio between the electrostatic chuck 112 on which the substrate W is placed and the annular electrostatic chuck 113 on which the ring assembly 120 is placed can be controlled.

[0077] The following describes in detail the method for controlling the capacitance ratio between the substrate W and the ring assembly 120 placed on the substrate support portion 11 according to this embodiment. Figures 5 and 6 are explanatory diagrams showing the capacitance between the substrate W and the ring assembly 120 in the substrate support section. Figure 5 is an explanatory diagram of a conventional substrate support structure without the discharge prevention electrode 114c, and Figure 6 is an explanatory diagram of the substrate support section 11 according to this embodiment with the discharge prevention electrode 114c. In the conventional substrate support structure shown in Figure 5, elements having substantially the same functional configuration as those in the substrate support section 11 according to this embodiment shown in Figure 6 are denoted by the same reference numerals and detailed explanations are omitted.

[0078] To improve the in-plane uniformity of plasma treatment on the substrate W, it is important to uniformly apply the high-frequency power (RF) applied to the conductive base 111 to both the substrate W and the ring assembly 120 (edge ​​ring), thereby uniformly attracting ions to the entire surface of the substrate W. However, since the high-frequency power applied to the conductive base 111 is applied to the substrate W and ring assembly 120 via the dielectric ceramic members 112a and 113a, respectively, a distribution may occur in the ratio of the high-frequency power applied to the substrate W and ring assembly 120, i.e., the impedance ratio between the substrate W and the ring assembly 120.

[0079] Specifically, the impedance of the substrate W is determined by the reciprocal of its capacitance [Cw]. The parasitic capacitance Cw of the substrate W may depend, for example, on the thickness of the dielectric material (ceramic material 112a) through which high-frequency power is transmitted, i.e., the distance between the conductive base 111 and the substrate W. Furthermore, the impedance of the ring assembly 120 is determined by the reciprocal of the capacitance [Cf × A1 / A2]. The parasitic capacitance Cf of the ring assembly 120 (see Figure 5) may depend, for example, on the thickness of the dielectric member (ceramic member 113a) through which the high-frequency power is transmitted, i.e., the distance between the conductive base 111 and the ring assembly 120. Also, the area A1 (see Figure 5) mentioned above is the exposure area of ​​the ring assembly 120 to the plasma processing space, i.e., the upper surface area of ​​the ring assembly 120. The area A2 (see Figure 5) mentioned above is the inlet area of ​​the high-frequency power to the ring assembly 120, i.e., the contact area between the ring assembly 120 and the annular region 110b.

[0080] As described above, the high-frequency power applied from the high-frequency power supply is distributed and propagated according to the impedance of the electrostatic chuck 112 on which the substrate W is mounted and the annular electrostatic chuck 113 on which the ring assembly 120 is mounted. However, in conventional substrate support sections that do not have discharge prevention electrodes 114c, as shown in Figure 5, the impedance (capacitance [Cw]) of the substrate W and the impedance (capacitance [Cf × A1 / A2]) of the ring assembly 120 do not match, and a distribution occurs in the capacitive coupling between the substrate W and the ring assembly 120.

[0081] In this respect, in the substrate support portion 11 according to this embodiment, where the discharge prevention electrode 114c is arranged, it is easy to match the capacitance [Cw] of the substrate W with the capacitance [Cf × A1 / A2] of the ring assembly 120. In other words, in the substrate support portion 11 according to this embodiment, as shown in Figure 6, the capacitance value of the parasitic capacitance Cw of the substrate W can be arbitrarily adjusted by changing the height position of the discharge prevention electrode 114c inside the ceramic member 112a, thereby adjusting the impedance ratio of the substrate W and the ring assembly 120. More specifically, the height of the discharge prevention electrode 114c is designed so that the capacitance [Cw] of the substrate W matches the capacitance [Cf × A1 / A2] of the ring assembly 120, thereby appropriately suppressing the occurrence of a distribution in the capacitive coupling between the substrate W and the ring assembly 120.

[0082] According to the substrate support portion 11 of this embodiment, in plasma treatment of the substrate W, it is possible to suppress abnormal discharge in the diffusion space of the heat transfer gas formed in the electrostatic chuck as shown in the above embodiment, and to adjust the high-frequency impedance characteristics in the substrate mounting portion and the ring mounting portion.

[0083] The embodiments disclosed herein should be considered in all respects to be illustrative and not restrictive. The above embodiments may be omitted, replaced, or modified in various ways without departing from the scope and spirit of the appended claims. [Explanation of symbols]

[0084] 11. Substrate support section 111 Conductive base 112a Ceramic component 113a Ceramic component 114c Electrode for preventing discharge 114c1 Conductive member 115a Diffusion space 116b Bias electrode 117a Diffusion space 120 Ring Assembly RFS high frequency power supply S2 Bias Power Supply W board

Claims

1. A base that is electrically connected to at least one power supply, A first dielectric portion is placed on the base and has a substrate support surface, The base comprises a second dielectric portion having a ring support surface, which is arranged to surround the first dielectric portion on the base, The first dielectric part is, A first heat transfer gas diffusion space for supplying heat transfer gas toward the substrate support surface, A first electrode is positioned above the first heat transfer gas diffusion space, such that it overlaps vertically with at least a portion of the first heat transfer gas diffusion space, It has a conductive part inside which it electrically connects the first electrode and the base, The second dielectric part is A second heat transfer gas diffusion space for supplying heat transfer gas toward the ring support surface, A substrate support having, inside, a second electrode positioned above the second heat transfer gas diffusion space so as to overlap vertically with at least a portion of the second heat transfer gas diffusion space, and electrically connected to a power supply that outputs a voltage common to the base.

2. The substrate support according to claim 1, wherein the first electrode and the second electrode are arranged in the same plane.

3. The first dielectric part is, The substrate support according to claim 1 or 2, further comprising a bias electrode for a substrate disposed above the first electrode.

4. The first dielectric part is, The substrate support according to claim 1 or 2, further comprising an electrostatic electrode for the substrate disposed above the first electrode.

5. The second dielectric part is The substrate support according to claim 1 or 2, further comprising a ring-type electrostatic electrode positioned above the second electrode.

6. The substrate support according to claim 1 or 2, wherein the second electrode is a bias electrode for a ring supported on the ring support surface.

7. The substrate support according to claim 1 or 2, wherein a plurality of the conductive portions are arranged along the circumferential direction of the first dielectric portion.

8. The substrate support according to claim 7, wherein the plurality of conductive parts are arranged at equal intervals along the circumferential direction of the first dielectric part.

9. Plasma processing chamber and A plasma processing apparatus comprising a substrate support disposed within the plasma processing chamber, The aforementioned substrate support is, A base that is electrically connected to at least one power supply, A first dielectric portion is placed on the base and has a substrate support surface, The base comprises a second dielectric portion having a ring support surface, which is arranged to surround the first dielectric portion on the base, The first dielectric part is, A first heat transfer gas diffusion space for supplying heat transfer gas toward the substrate support surface, A first electrode positioned above the first heat transfer gas diffusion space, It has a conductive part inside which it electrically connects the first electrode and the base, The second dielectric part is A second heat transfer gas diffusion space for supplying heat transfer gas toward the ring support surface, A plasma processing apparatus having inside a second electrode positioned above the second heat transfer gas diffusion space and electrically connected to a power supply that outputs a voltage common to the base.

10. The plasma processing apparatus according to claim 9, further comprising an edge ring placed on the ring support surface.

11. The plasma processing apparatus according to claim 10, wherein the second electrode is a bias electrode for edge ringing.

12. The plasma processing apparatus according to claim 10 or 11, wherein the area of ​​the ring support surface of the second dielectric portion is smaller than the area of ​​the lower surface of the edge ring supported by the ring support surface.

13. The plasma processing apparatus according to any one of claims 9 to 11, wherein the first electrode and the second electrode are arranged in the same plane.

14. The first dielectric part is, The plasma processing apparatus according to any one of claims 9 to 11, further comprising a substrate bias electrode disposed above the first electrode.

15. The first dielectric part is, The plasma processing apparatus according to any one of claims 9 to 11, further comprising an electrostatic electrode for a substrate disposed above the first electrode.

16. The second dielectric part is The plasma processing apparatus according to any one of claims 9 to 11, further comprising a ring-shaped electrostatic electrode positioned above the second electrode.

17. The plasma processing apparatus according to any one of claims 9 to 11, wherein a plurality of the conductive portions are arranged along the circumferential direction of the first dielectric portion.

18. The plasma processing apparatus according to claim 17, wherein the plurality of conductive parts are arranged at equal intervals along the circumferential direction of the first dielectric part.

Images