Electrostatic chuck, substrate support device, and substrate processing device

Abstract

The present invention provides an electrostatic chuck, comprising: a center region for supporting a substrate; at least one through hole formed in the center region; a first substrate contact part positioned around the through hole; and a second substrate contact part positioned around the first substrate contact part. The first substrate part and the second substrate contact part have a plurality of projections projecting upward from the center region. The projections are positioned at a first density on the first substrate contact part, and positioned at a second density on the second substrate contact part, the second density being lower than the first density .

Description

Electrostatic chuck, substrate support, and substrate processing apparatus

[0001] The present disclosure relates to an electrostatic chuck, a substrate support, and a substrate processing apparatus.

[0002] Patent Document 1 discloses an electrostatic chuck provided with holes for lift pins and holes for supplying and exhausting ionized gas.

[0003] JP 2018-186179 A

[0004] The technology according to the present disclosure suppresses the occurrence of temperature singularities in the substrate near the through-hole of the electrostatic chuck.

[0005] One aspect of the present disclosure is an electrostatic chuck comprising: a central region for supporting a substrate; at least one through hole formed in the central region; a first substrate contact portion arranged around the through hole; and a second substrate contact portion arranged around the first substrate contact portion, wherein the first substrate contact portion and the second substrate contact portion have a plurality of protrusions protruding upward from the central region, the protrusions being arranged at a first density on the first substrate contact portion, and the protrusions being arranged at a second density that is less than the first density on the second substrate contact portion.

[0006] According to the present disclosure, it is possible to suppress the occurrence of temperature singularities in the substrate near the through-hole of the electrostatic chuck.

[0007] 1. A diagram for explaining an example of the configuration of a plasma processing system. 2. A block diagram of a computer capable of implementing various embodiments. 3. A diagram for explaining an example of the configuration of a capacitively coupled plasma processing apparatus. 4. A plan view schematically showing an outline of the configuration of an electrostatic chuck. 5. A plan view enlarged of the periphery of a through hole of an electrostatic chuck according to a first embodiment. 6. A longitudinal sectional view of the periphery of the through hole shown in FIG. 5. 7. A plan view enlarged of the periphery of a through hole of an electrostatic chuck according to a second embodiment. 8. A longitudinal sectional view of the periphery of the through hole shown in FIG. 7. 9. A plan view enlarged of the periphery of a through hole of an electrostatic chuck according to a third embodiment. 10. A longitudinal sectional view of the periphery of the through hole shown in FIG. 9. 11. A plan view schematically showing an outline of the configuration of an electrostatic chuck according to a fourth embodiment. 12. A plan view enlarged of the periphery of a through hole formed in an annular region of an electrostatic chuck. 13. A longitudinal sectional view of the periphery of the through hole shown in FIG.

[0008] In the manufacturing process of semiconductor devices, a semiconductor substrate (hereinafter referred to as "substrate") is subjected to plasma processing in, for example, a plasma processing apparatus, which generates plasma by exciting a processing gas inside a chamber, and processes the substrate supported by an electrostatic chuck using the plasma.

[0009] In plasma processing, in order to improve the in-plane uniformity of the plasma processing on the substrate, it is necessary to appropriately control the temperature of the substrate to be processed. Therefore, for example, a heat transfer gas such as helium gas is supplied to the space between the back surface of the substrate and the front surface of the electrostatic chuck, and the temperature of the substrate is controlled by controlling the pressure of the heat transfer gas.

[0010] The electrostatic chuck is provided with through-holes for supplying the heat transfer gas, and also with through-holes for inserting lifter pins for transferring the substrate therethrough.

[0011] In plasma processing, the fewer areas where the temperature of the substrate becomes locally high (hereinafter referred to as "temperature singularities"), the more uniform the plasma processing can be achieved within the surface. However, temperature singularities are likely to occur in the vicinity of the above-mentioned through holes during plasma processing.

[0012] Therefore, the technology according to the present disclosure suppresses the occurrence of temperature singularities in the substrate near the through-hole of the electrostatic chuck.

[0013] Hereinafter, a substrate processing apparatus, a substrate support, and an electrostatic chuck according to the present embodiment will be described with reference to the drawings. In this specification and the drawings, elements having substantially the same functional configurations are designated by the same reference numerals, and redundant description will be omitted.

[0014] <Plasma Processing System> First, a plasma processing system according to one embodiment will be described with reference to Fig. 1. Fig. 1 is a diagram for explaining an example of the configuration of the plasma processing system.

[0015] 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 11, and a plasma generation unit 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 exhaust port for exhausting gas from the plasma processing space. The gas supply port is connected to a gas supply unit 20 (described later), and the gas exhaust port is connected to an exhaust system 40 (described later). The substrate support 11 is disposed in the plasma processing space and has a substrate support surface for supporting a substrate.

[0016] The plasma generating unit 12 is configured to generate plasma from at least one processing gas supplied into the plasma processing space. The plasma generated in the plasma processing space may be capacitively coupled plasma (CCP), inductively coupled plasma (ICP), electron-cyclotron-resonance plasma (ECR plasma), helicon wave plasma (HWP), or surface wave plasma (SWP). Various types of plasma generators may be used, including alternating current (AC) plasma generators and direct current (DC) plasma generators. In one embodiment, the AC signal (AC power) used in the AC plasma generator has a frequency in the range of 100 kHz to 10 GHz. Thus, AC signals include radio frequency (RF) signals and microwave signals. In one embodiment, the RF signal has a frequency in the range of 100 kHz to 150 MHz.

[0017] The control unit 2 processes computer-executable instructions that cause the plasma processing apparatus 1 to perform various processes described in this disclosure. The control unit 2 may be configured to control each element of the plasma processing apparatus 1 to perform 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 may be implemented by, for example, a computer 2a. The processing unit 2a1 may be configured to read a program from the storage unit 2a2 and execute the read program to perform various control operations. This program may be stored in the storage unit 2a2 in advance or may be acquired via a medium when needed. The acquired program is stored in the storage unit 2a2 and read from the storage unit 2a2 by the processing unit 2a1 for execution. The medium may be various storage media readable by the computer 2a or a communication line connected to the communication interface 2a3. The processing unit 2a1 may be a CPU (Central Processing Unit). The storage unit 2a2 may include a random access memory (RAM), a read-only memory (ROM), a hard disk drive (HDD), a solid state drive (SSD), or a combination thereof. The communication interface 2a3 may communicate with the plasma processing apparatus 1 via a communication line such as a local area network (LAN).

[0018] 2 is a block diagram of a computer that may implement various embodiments described herein. Control aspects of the present disclosure may be embodied as a system, method, and / or computer program product. The computer program product may include a computer-readable storage medium having computer-readable program instructions recorded thereon, where one or more processors may perform aspects of the embodiments.

[0019] A computer-readable storage medium may be a tangible device capable of storing instructions for use by an instruction execution device (processor). Examples of computer-readable storage media include, but are not limited to, electronic, magnetic, optical, electromagnetic, and semiconductor storage devices, or any suitable combination of these devices. A non-exhaustive list of more specific examples of computer-readable storage media (and suitable combinations) includes each of the following: floppy 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 versatile disks (DVDs), and memory cards or sticks. Computer-readable storage media, as used in this disclosure, should not be construed as being transitory signals themselves, such as radio waves or other freely propagating electromagnetic waves, electromagnetic waves propagating through a waveguide or other transmission medium (e.g., light pulses passing through a fiber optic cable), or electrical signals passing through electrical wires.

[0020] The computer-readable program instructions described in this disclosure can be downloaded to a suitable computing or processing device from a computer-readable storage medium or to an external computer or external storage 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, fiber optics, wireless transmissions, routers, firewalls, switches, gateway computers, and edge servers. A network adapter card or network interface of each computing or processing device may receive the computer-readable program instructions from the network and transfer the computer-readable program instructions for storage in a computer-readable storage medium within the computing or processing device.

[0021] Computer-readable program instructions for carrying out the operations of the present disclosure include machine language instructions and / or microcode, and may 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 execute entirely on a user's personal computer, notebook computer, tablet, or smartphone, or entirely on a remote computer or computer server, or any combination of these computing devices. The remote computer or computer server may be connected to the user's device or devices via a computer network, including a local area network, a wide area network, or a global network (e.g., the Internet). In some embodiments, electronic circuitry, including, for example, a programmable logic circuit, a field programmable gate array (FPGA), or a programmable logic array (PLA), executes the computer-readable program instructions using information from the computer-readable program instructions to configure or customize the electronic circuitry to carry out aspects of the present disclosure.

[0022] Aspects of the present disclosure are described with reference to flow diagrams and block diagrams of methods, apparatus (systems), and computer program products according to the disclosed embodiments. 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.

[0023] Computer-readable program instructions capable of implementing the systems and methods described in this disclosure may be provided to one or more processors (and / or one or more cores within a processor) of a general-purpose computer, special-purpose computer, or other programmable device. These computer-readable program instructions may be stored on a computer-readable storage medium that can direct a computer, programmable device, and / or other device to function in a particular manner, in which case the computer-readable storage medium storing the instructions is an article of manufacture containing instructions that implement aspects of the functionality specified in the flow diagrams and block diagrams of this disclosure.

[0024] The computer-readable program instructions may also be loaded into a computer, other programmable device, or other apparatus, and the instructions, when executed on the computer, other programmable device, or other apparatus, may cause a series of operational steps to be performed to produce a computer-implemented process such that the functions specified in the flow diagrams and block diagrams of this disclosure are implemented.

[0025] 2 is a functional block diagram illustrating a networked system 800 of one or more networked computers and servers. In one embodiment, the hardware and software environment illustrated in FIG. 2 may provide an exemplary platform for implementation of software and / or methods according to the present disclosure.

[0026] As shown in Figure 2, 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 of the functional blocks shown in Figure 2 may be employed.

[0027] Additional details of computer 805 are shown in Figure 2. The functional blocks shown in computer 805 are provided only to establish example functionality and are not intended to be exhaustive. Also, although details are not provided for remote computer 815, web server 820, cloud storage server 825, and computer server 830, these other computers and devices may have similar functionality shown for computer 805.

[0028] The computer 805 can be a personal computer (PC), a desktop computer, a laptop computer, a tablet computer, a netbook computer, a personal digital assistant (PDA), a smartphone, or any other programmable electronic device capable of communicating with other devices on the network 810.

[0029] Computer 805 may include a processor 835, a bus 837, memory 840, non-volatile storage 845, a network interface 850, a peripherals 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 combination of chips and associated devices), or in other embodiments, some combination of functions may be implemented on a single chip (sometimes called a system on a chip, or SoC).

[0030] Processor 835 may be one or more single or multi-chip microprocessors.

[0031] Bus 837 may be a proprietary standard high-speed parallel or serial peripheral interconnect bus such as ISA, PCI, PCI Express (PCI-e), AGP, or the like.

[0032] The memory 840 and the non-volatile storage 845 may 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 a floppy disk, a hard disk, a solid-state drive (SSD), a read-only memory (ROM), a programmable read-only memory (EPROM or Flash), a compact disk (CD or CD-ROM), a digital versatile disk (DVD), and a memory card or stick.

[0033] Program 848 may be a collection of machine-readable instructions and / or data stored in non-volatile storage 845 and used to create, manage, and control certain software functions described in detail elsewhere in this disclosure and illustrated in the figures. In some embodiments, memory 840 may be significantly faster than non-volatile storage 845. In such embodiments, program 848 may be transferred from non-volatile storage 845 to memory 840 before being executed by processor 835.

[0034] Computer 805 can communicate and interact with other computers over network 810 via network interface 850. 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, wired, wireless, or fiber optic connections. In general, network 810 can be any combination of connections and protocols that support communication between two or more computers and associated devices.

[0035] The peripheral interface 855 may enable input and output of data between the computer 805 and other devices that may be locally connected. 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, a mouse, a keypad, a touchscreen, and / or other suitable input devices. The external device 860 may also include portable computer-readable storage media, such as thumb drives, portable optical or magnetic disks, and memory cards. Software and data used in embodiments of the present disclosure may be stored, for example, in the program 848, a portable computer-readable storage medium, or the like. In such embodiments, software may be loaded into the non-volatile storage 845 or, alternatively, directly into the memory 840 via the peripheral interface 855. The peripheral interface 855 may connect to the external device 860 using an industry-standard connection, such as RS-232 or Universal Serial Bus (USB).

[0036] Display interface 865 may connect computer 805 to a display 870. Display 870 may be used in some embodiments to present a command line or graphical user interface to a user of computer 805. Display interface 865 may connect to display 870 using one or more proprietary connections or industry standard connections such as VGA, DVI, DisplayPort, HDMI, etc.

[0037] As mentioned above, network interface 850 provides for communication with other computing and storage systems or devices external to computer 805. Software programs and data described herein may be downloaded to non-volatile storage 845 via network interface 850 and network 810 from, for example, remote computer 815, web server 820, cloud storage server 825, and computer server 830. Additionally, the systems and methods described in this disclosure may be performed by one or more computers connected to computer 805 via network interface 850 and network 810. For example, in some embodiments, the systems and methods described in this disclosure may be performed by remote computer 815, computer server 830, or a combination of interconnected computers on network 810.

[0038] Data, datasets and / or databases used in embodiments of the implementation of the systems and methods described in this disclosure may be stored or downloaded from a remote computer 815, a web server 820, a cloud storage server 825 and a computer server 830.

[0039] Next, a configuration example of a capacitively coupled plasma processing apparatus will be described as an example of the plasma processing apparatus 1. Fig. 3 is a diagram for explaining the configuration example of the capacitively coupled plasma processing apparatus. Fig. 4 is a plan view schematically showing the outline of the configuration of an electrostatic chuck.

[0040] The capacitively coupled plasma processing apparatus 1 includes a plasma processing chamber 10, a gas supply unit 20, a power supply 30, and an exhaust system 40. The plasma processing apparatus 1 also includes a substrate support 11 as an example of a substrate support, and a gas inlet. The gas inlet is configured to introduce at least one process gas into the plasma processing chamber 10. The gas inlet includes a showerhead 13. The substrate support 11 is disposed within the plasma processing chamber 10. The showerhead 13 is disposed above the substrate support 11. In one embodiment, the showerhead 13 forms at least a portion of the ceiling of the plasma processing chamber 10. The plasma processing chamber 10 has a plasma processing space 10s defined by the showerhead 13, a sidewall 10a of the plasma processing chamber 10, and the substrate support 11. The plasma processing chamber 10 is grounded. The showerhead 13 and the substrate support 11 are electrically insulated from the housing of the plasma processing chamber 10.

[0041] The substrate support 11 includes a main body 111 and a ring assembly 112. The main body 111 has a central region 111a for supporting a substrate W and an annular region 111b for supporting the ring assembly 112. A wafer is an example of a substrate W. The annular region 111b of the main body 111 surrounds the central region 111a of the main body 111 in a plan view. The substrate W is disposed on the central region 111a of the main body 111, and the ring assembly 112 is disposed on the annular region 111b of the main body 111 so as to surround the substrate W on the central region 111a of the main body 111. Therefore, the central region 111a is also called a substrate support surface for supporting the substrate W, and the annular region 111b is also called a ring support surface for supporting the ring assembly 112.

[0042] In one embodiment, the main body 111 includes a base 1110 and an electrostatic chuck 1111. The base 1110 includes a conductive material such as aluminum and has a generally disk-like shape. The conductive material of the base 1110 can function as a lower electrode. The electrostatic chuck 1111 is formed by sintering an insulating material such as ceramic or by thermally spraying an insulating material. The electrostatic chuck 1111 is disposed on the base 1110 via a bonding layer. The bonding layer is formed of a plasma-resistant and heat-resistant material. For example, an acrylic resin, a silicone resin, an epoxy resin, or the like can be used. The electrostatic chuck 1111 includes an insulating member 1111a and a first electrostatic electrode 1111b and a second electrostatic electrode 1111c disposed within the insulating member 1111a. The insulating member 1111a has a central region 111a. In one embodiment, the insulating member 1111a also has an annular region 111b. The central region 111 a and the annular region 111 b may be formed integrally or separately. In one embodiment, the first electrostatic electrode 1111 b is used, for example, as an electrode for electrostatically attracting the substrate W supported by the central region 111 a. The second electrostatic electrode 1111 c is used, for example, as an electrode for electrostatically attracting the ring assembly 112 supported by the annular region 111 b surrounding the central region 111 a.

[0043] In one embodiment, another member surrounding the electrostatic chuck 1111, such as an annular electrostatic chuck or an annular insulating member, may have the annular region 111b. In this case, the ring assembly 112 may be disposed on the annular electrostatic chuck or the annular insulating member, or may be disposed on both the electrostatic chuck 1111 and the annular insulating member. At least one RF / DC electrode coupled to an RF power supply 31 and / or a DC power supply 32 (described later) may be disposed within the insulating member 1111a. In this case, the at least one RF / DC electrode functions as a lower electrode. When a bias RF signal and / or a DC signal (described later) is supplied to the at least one RF / DC electrode, the RF / DC electrode is also referred to as a bias electrode. Note that the conductive member of the base 1110 and the at least one RF / DC electrode may function as multiple lower electrodes. Alternatively, the first electrostatic electrode 1111b may function as the lower electrode. Thus, the substrate support 11 includes at least one lower electrode.

[0044] The ring assembly 112 includes one or more annular members. In one embodiment, the one or more annular members include one or more edge rings and at least one cover ring. The edge rings are formed of a conductive or insulating material, and the cover rings are formed of an insulating material.

[0045] The substrate support 11 may also include a temperature adjustment module configured to adjust at least one of the electrostatic chuck 1111, the ring assembly 112, and the substrate to a target temperature. The temperature adjustment module may include a heater, a heat transfer medium, a flow path 1110a, or a combination thereof. A heat transfer fluid such as brine or gas flows through the flow path 1110a. In one embodiment, the flow path 1110a is formed in the base 1110, and one or more heaters are disposed in the insulating member 1111a of the electrostatic chuck 1111. The substrate support 11 may also include a heat transfer gas supply unit 50 configured to supply a heat transfer gas to a gap between the back surface of the substrate W and the central region 111a. The heat transfer gas supply unit 50 supplies the heat transfer gas via a gas supply path 51 to a plurality of gas supply holes 120a ( FIG. 4 ) formed in the electrostatic chuck 1111. The gas supply holes 120a are through-holes that vertically penetrate the electrostatic chuck 1111. In one embodiment, the gas supply holes 120 a are spaced apart from one another and arranged concentrically around the center of the circular central region 111 a. The gas supply holes 120 a can also be used as holes for exhausting heat transfer gas between the back surface of the substrate W and the central region 111 a.

[0046] In one embodiment, the electrostatic chuck 1111 has a plurality of first pin insertion holes 120b ( FIG. 4 ) as other through holes in the central region 111a. The first pin insertion holes 120b are through holes through which first lifter pins 60 that support and raise and lower the substrate W are inserted, and extend in the vertical direction. In one embodiment, the plurality of first pin insertion holes 120b are arranged at intervals from one another, and each of the first pin insertion holes 120b is arranged on the same circumference with the center of the circular central region 111a as the center of the circle. The first lifter pins 60 are configured to be able to rise and fall by being connected to a drive unit 61. The drive unit 61 has, for example, a motor (not shown) that generates a lifting and lowering drive force.

[0047] In one embodiment, the electrostatic chuck 1111 has a plurality of second pin insertion holes 120c ( FIG. 4 ) as other through holes in the annular region 111b. The second pin insertion holes 120c are through holes through which second lifter pins 70 that support and raise and lower the ring assembly 112 are inserted, and extend in the vertical direction. In one embodiment, the plurality of second pin insertion holes 120c are arranged at intervals from one another, and each of the second pin insertion holes 120c is arranged on the same circumference with the center of the circular annular region 111b as the center of the circle. The second lifter pins 70 are configured to be able to rise and fall by being connected to a drive unit 71. The drive unit 71 includes, for example, a motor (not shown) that generates a lifting and lowering driving force.

[0048] The electrostatic chuck 1111 has a substrate contact portion 130 ( FIG. 4 ) that includes a plurality of protrusions 131. The plurality of protrusions 131 are arranged in a central region 111 a and protrude upward from the central region 111 a. When these protrusions 131 come into contact with the rear surface of the substrate W, a space is formed between the substrate W and the central region 111 a, and a heat transfer gas diffuses into this space. The arrangement of the protrusions 131 will be described in detail later.

[0049] The showerhead 13 is configured to introduce at least one process gas from the gas supply unit 20 into the plasma processing space 10s. The showerhead 13 has at least one gas supply port 13a, at least one gas diffusion chamber 13b, and multiple gas inlets 13c. The process gas supplied to the gas supply port 13a passes through the gas diffusion chamber 13b and is introduced into the plasma processing space 10s from the multiple gas inlets 13c. The showerhead 13 also includes at least one upper electrode. In addition to the showerhead 13, the gas inlet may also include one or more side gas injectors (SGIs) attached to one or more openings formed in the sidewall 10a.

[0050] The gas supply unit 20 may include at least one gas source 21 and at least one flow controller 22. In one embodiment, the gas supply unit 20 is configured to supply at least one process gas from a corresponding gas source 21 to the showerhead 13 via a corresponding flow controller 22. Each flow controller 22 may include, for example, a mass flow controller or a pressure-controlled flow controller. Additionally, the gas supply unit 20 may include at least one flow modulation device that modulates or pulses the flow rate of the at least one process gas.

[0051] 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 generates a plasma from at least one processing gas supplied to the plasma processing space 10s. Therefore, the RF power supply 31 can function as at least a part of the plasma generation unit 12. Furthermore, by supplying a bias RF signal to the at least one lower electrode, a bias potential is generated on the substrate W, thereby attracting ion components in the formed plasma to the substrate W.

[0052] 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 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 generating unit 31a may be configured to generate multiple source RF signals having different frequencies. The generated one or more source RF signals are supplied to at least one lower electrode and / or at least one upper electrode.

[0053] The second RF generator 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 generator 31b may be configured to generate multiple bias RF signals having different frequencies. The generated one or more 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.

[0054] 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 generator 32a and a second DC generator 32b. In one embodiment, the first DC generator 32a is connected to the at least one lower electrode and configured to generate a first DC signal. The generated first DC signal is applied to the at least one lower electrode. In one embodiment, the second DC generator 32b is connected to the at least one upper electrode and configured to generate a second DC signal. The generated second DC signal is applied to the at least one upper electrode.

[0055] 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 combination thereof pulse waveform. In one embodiment, a waveform generator for generating the sequence of voltage pulses from the DC signal is connected between the first DC generator 32a and at least one lower electrode. Thus, the first DC generator 32a and the waveform generator constitute a voltage pulse generator. When the second DC generator 32b and the waveform generator constitute a voltage pulse generator, the voltage pulse generator is connected to at least one upper electrode. The voltage pulses may have either positive or negative polarity. Furthermore, the sequence of voltage pulses may include one or more positive voltage pulses and one or more negative voltage pulses within one period. The first and second DC generating units 32a and 32b may be provided in addition to the RF power supply 31, or the first DC generating unit 32a may be provided instead of the second RF generating unit 31b.

[0056] The exhaust system 40 may be connected to, for example, a gas exhaust port 10e provided at the bottom of the plasma processing chamber 10. The exhaust system 40 may include a pressure regulating valve and a vacuum pump. The pressure in the plasma processing space 10s is regulated by the pressure regulating valve. The vacuum pump may include a turbomolecular pump, a dry pump, or a combination thereof.

[0057] Next, the arrangement of the plurality of protrusions 131 of the electrostatic chuck 1111 will be described by taking a plurality of embodiments as examples.

[0058] First Embodiment Fig. 5 is an enlarged plan view of the periphery of a through hole of an electrostatic chuck according to a first embodiment, and Fig. 6 is a vertical cross-sectional view of the periphery of the through hole shown in Fig. 5.

[0059] In this embodiment, ten protrusions 131 are arranged at positions of radius R1 from the center of the through hole 120 (for example, the gas supply hole 120a or the first pin insertion hole 120b shown in FIG. 4). Ten protrusions 131 are arranged at positions of radius R2 from the center of the through hole 120, and sixteen protrusions 131 are arranged at positions of radius R3 from the center of the through hole 120. The protrusions 131 are arranged concentrically with the center of the through hole 120 as the center of the circle. When the through hole 120 is a hole for inserting the first lifter pin 60, the radius R1 is, for example, 3.9 mm. When the through hole 120 is a hole for supplying a heat transfer gas, the radius R1 is, for example, 3.55 mm. The preferred distance from the through hole 120 to each protrusion 131 can be changed as appropriate depending on the positional relationship between the through hole 120 and the first electrostatic electrode 1111b, etc.

[0060] In the substrate contact portion 130 in which the protrusions 131 are arranged as described above, the density of the protrusions 131 varies in the radial direction of the through hole 120. Note that the "density of the protrusions" in this specification refers to the number of protrusions 131 per unit area. In this embodiment, the number of protrusions 131 per unit area in the region from the center of the through hole 120 to the position of radius R1 is greater than the number of protrusions 131 per unit area in the region from the position of radius R1 to the position of radius R3. Therefore, the substrate contact portion 130 according to this embodiment includes a first substrate contact portion 130a and a second substrate contact portion 130b in which the density of the protrusions 131 varies in the radial direction of the through hole 120.

[0061] The first substrate contact portion 130a is arranged around the through hole 120, and the second substrate contact portion 130b is arranged around the first substrate contact portion 130a. If the density of the protrusions 131 on the first substrate contact portion 130a is defined as a first density, the protrusions 131 on the second substrate contact portion 130b are arranged at a second density that is smaller than the first density. That is, the electrostatic chuck 1111 according to this embodiment has the first substrate contact portion 130a on which the protrusions 131 are arranged at the first density, and the second substrate contact portion 130b on which the protrusions 131 are arranged at the second density that is smaller than the first density.

[0062] When the protrusions 131 come into contact with the substrate W, heat is transferred from the substrate W to the protrusions 131 by thermal conduction, thereby cooling the substrate W. Therefore, the cooling capacity of the substrate W increases as the number of protrusions 131 increases. Therefore, by having the first substrate contact portions 130a, which have a higher density of protrusions 131 than the second substrate contact portions 130b, present around the through holes 120, the cooling capacity of the substrate W in the vicinity of the through holes 120 can be locally increased. This makes it possible to suppress a local temperature rise of the substrate W in the vicinity of the through holes 120 during plasma processing. In other words, the electrostatic chuck 1111 according to this embodiment can suppress the occurrence of temperature singularities of the substrate W in the vicinity of the through holes 120.

[0063] Note that the arrangement of the protrusions 131 and the number of the protrusions 131 are not particularly limited as long as the condition that the second density is lower than the first density is satisfied. Furthermore, for example, the protrusions 131 do not have to be arranged concentrically. However, the local temperature rise region of the substrate W near the through-hole 120 tends to be circular. Therefore, from the viewpoint of uniformly cooling the local temperature rise region of the substrate W, it is preferable that the protrusions 131 of the first substrate contact portion 130a be arranged concentrically with the center of the through-hole 120 as the center of the circle.

[0064] Furthermore, it is preferable that at least a portion of the first substrate contact portion 130a is located above the first electrostatic electrode 1111b provided inside the electrostatic chuck 1111. This increases the attraction force of the first substrate contact portion 130a with respect to the substrate W and increases the contact area of ​​the first substrate contact portion 130a with respect to the substrate W. As a result, the amount of heat transferred from the substrate W to the first substrate contact portion 130a by thermal conduction increases, making it possible to effectively suppress a local temperature rise in the substrate W.

[0065] Second Embodiment Fig. 7 is an enlarged plan view of the periphery of a through hole of an electrostatic chuck according to a second embodiment, and Fig. 8 is a vertical cross-sectional view of the periphery of the through hole shown in Fig. 7 .

[0066] In this embodiment, the first substrate contact portion 130a has protrusions 131a (hereinafter referred to as "end protrusions") arranged above the end of the first electrostatic electrode 1111b on the through-hole 120 side. Ten end protrusions 131a are arranged at a radius R1 from the center of the through-hole 120. The first substrate contact portion 130a also has protrusions 131b (hereinafter referred to as "inner protrusions") arranged radially inward of the through-hole 120 (toward the center of the through-hole 120) relative to the end protrusions 131a. Six inner protrusions 131b are arranged at a radius R4 from the center of the through-hole 120. The protrusions 131 are arranged concentrically with the center of the through-hole 120 as the center of the circle. When the through-hole 120 is a hole for inserting the first lifter pin 60, the radius R1 is, for example, 3.9 mm, and the radius R4 is, for example, 2.5 mm. When the through hole 120 is a hole for supplying a heat transfer gas, the radius R1 is, for example, 3.55 mm, and the radius R4 is, for example, 1.78 mm. Note that the preferred distance from the through hole 120 of each protrusion 131, including the end protrusion 131 a and the inner protrusion 131 b, to the through hole 120 can be changed as appropriate depending on the positional relationship between the through hole 120 and the first electrostatic electrode 1111 b, etc.

[0067] In the electrostatic chuck 1111 according to this embodiment, the density of the protrusions 131 arranged on the first substrate contact portion 130a is also greater than the density of the protrusions 131 arranged on the second substrate contact portion 130b. Therefore, the cooling capacity of the substrate W at the first substrate contact portion 130a is relatively higher than that at the second substrate contact portion 130b. Furthermore, the provision of the inner protrusions 131b on the first substrate contact portion 130a improves the cooling capacity of the substrate W at the first substrate contact portion 130a. Therefore, the electrostatic chuck 1111 according to this embodiment makes it easier to suppress a local temperature rise of the substrate W in the vicinity of the through hole 120.

[0068] Third Embodiment Fig. 9 is an enlarged plan view of the periphery of a through hole of an electrostatic chuck according to a third embodiment, and Fig. 10 is a vertical cross-sectional view of the periphery of the through hole shown in Fig. 9 .

[0069] In this embodiment, the first substrate contact portion 130a has protrusions 131c (hereinafter referred to as "outer protrusions") arranged radially outward of the through hole 120 (on the opposite side from the center of the through hole 120) relative to the end protrusions 131a. Sixteen outer protrusions 131c are arranged at a radius R5 from the center of the through hole 120. The protrusions 131c are arranged concentrically with the center of the through hole 120 as the center of the circle. When the through hole 120 is a hole for inserting the first lifter pin 60, the radius R1 is, for example, 3.9 mm, and the radius R5 is, for example, 6.2 mm. When the through hole 120 is a hole for supplying heat transfer gas, the radius R1 is, for example, 3.55 mm, and the radius R5 is, for example, 5.85 mm. The preferred distance of each protrusion 131, including the end protrusion 131a and the outer protrusion 131c, from the through-hole 120 can be changed as appropriate depending on the positional relationship between the through-hole 120 and the first electrostatic electrode 1111b.

[0070] In the electrostatic chuck 1111 according to this embodiment, the density of the protrusions 131 arranged on the first substrate contact portion 130a is also greater than the density of the protrusions 131 arranged on the second substrate contact portion 130b. Therefore, the cooling capacity of the substrate W at the first substrate contact portion 130a is relatively higher than that at the second substrate contact portion 130b. Furthermore, the provision of the outer protrusions 131c on the first substrate contact portion 130a improves the cooling capacity of the substrate W at the first substrate contact portion 130a. Therefore, the electrostatic chuck 1111 according to this embodiment makes it easier to suppress a local temperature rise of the substrate W in the vicinity of the through hole 120.

[0071] <Fourth embodiment> Fig. 11 is a plan view schematically illustrating the configuration of an electrostatic chuck according to a fourth embodiment. Fig. 12 is an enlarged plan view of the periphery of a through hole formed in an annular region of the electrostatic chuck. Fig. 13 is a vertical cross-sectional view of the periphery of the through hole shown in Fig. 12.

[0072] The electrostatic chuck 1111 according to this embodiment has a ring contact portion 132 in the annular region 111b in addition to the substrate contact portion 130. The ring contact portion 132 has a plurality of protrusions 131 protruding upward from the annular region 111b.

[0073] Ten protrusions 131 in the annular region 111b are arranged at positions of radius R6 from the center of the through hole 120 (for example, the second pin insertion hole 120c shown in FIG. 11). Ten protrusions 131 are arranged at positions of radius R7 from the center of the through hole 120, and sixteen protrusions 131 are arranged at positions of radius R8 from the center of the through hole 120. The protrusions 131 are arranged concentrically with the center of the through hole 120 as the center of the circle. Note that the preferred distance from the through hole 120 to each protrusion 131 can be changed as appropriate depending on the positional relationship between the through hole 120 and the second electrostatic electrode 1111c, etc.

[0074] The ring contact portion 132 having the protrusions 131 arranged as described above has a first ring contact portion 132a and a second ring contact portion 132b, in which the density of the protrusions 131 differs in the radial direction of the through hole 120. The first ring contact portion 132a is arranged around the through hole 120, and the second ring contact portion 132b is arranged around the first ring contact portion 132a. If the density of the protrusions 131 in the first ring contact portion 132a is defined as a third density, the protrusions 131 in the second ring contact portion 132b are arranged at a fourth density that is lower than the third density. That is, the electrostatic chuck 1111 according to this embodiment has the first ring contact portion 132a in which the protrusions 131 are arranged at the third density and the second ring contact portion 132b in which the protrusions 131 are arranged at a fourth density that is lower than the third density.

[0075] During plasma processing, there is a concern that a local temperature rise in the ring assembly 112 occurs near the through hole 120 in the annular region 111b, which may result in the generation of temperature singularities around the peripheral edge of the substrate W. On the other hand, in the electrostatic chuck 1111 according to this embodiment, the first ring contact portion 132a, which has a higher density of protrusions 131 than the second ring contact portion 132b, is present around the through hole 120. This makes it possible to locally increase the cooling capacity of the ring assembly 112 near the through hole 120. This makes it possible to suppress a local temperature rise in the ring assembly 112 that may occur near the through hole 120 during plasma processing, thereby suppressing the generation of temperature singularities around the peripheral edge of the substrate W.

[0076] As long as the condition that the fourth density is lower than the third density is satisfied, there is no particular limitation on the arrangement of the protrusions 131 on the ring contact portion 132 or the number of the protrusions 131. For example, the inner protrusions 131b and the outer protrusions 131c described in the second and third embodiments may be applied to the ring contact portion 132.

[0077] In the first to fourth embodiments described above, the arrangement of the protrusions 131 provided on the electrostatic chuck 1111 has been described. However, the arrangement of the protrusions 131 may be an appropriate combination of the arrangements described in the first to fourth embodiments. Furthermore, the shape of the protrusions 131 in a plan view is not particularly limited and may be circular, triangular, rectangular, or another shape. In the case of circular protrusions 131, the protrusions 131 have a diameter of, for example, 0.2 to 1.0 mm. The protrusions 131 do not have to have the same shape. Furthermore, the heights of the protrusions 131 (the heights from the central region 111a or the annular region 111b to the upper ends of the protrusions 131) do not have to be the same. Furthermore, the first density and the third densities may be the same or different, and the second density and the fourth densities may be the same or different.

[0078] In the above embodiment, the gas supply hole 120a, the first pin insertion hole 120b, and the second pin insertion hole 120c are exemplified as examples of the uses of the through hole 120. However, the use of the through hole 120 is not particularly limited. For example, the through hole 120 may be a hole for inserting a temperature sensor for measuring the substrate temperature. By providing the first substrate contact portion 130a and the second substrate contact portion 130b with different radial densities in the through hole, the occurrence of temperature singularities on the substrate W near the through hole as described above can be suppressed. The number of through holes is also not particularly limited. Even if there is only one through hole, the occurrence of temperature singularities on the substrate W near the through hole can be suppressed by applying the electrostatic chuck 1111 described in the above embodiment to the through hole.

[0079] The embodiments disclosed herein should be considered to be illustrative in all respects and not restrictive, and the above-described embodiments may be omitted, substituted, or modified in various ways without departing from the scope and spirit of the appended claims.

[0080] REFERENCE SIGNS LIST 1 Plasma processing apparatus 10 Plasma processing chamber 11 Substrate support portion 111a Central region 120 Through-hole 130a First substrate contact portion 130b Second substrate contact portion 131 Protrusion 1110 Base 1111 Electrostatic chuck W Substrate

Claims

1. a central region for supporting a substrate; At least one through hole formed in the central region; a first board contact portion disposed around the through hole; a second substrate contact portion disposed around the first substrate contact portion; the first substrate contact portion and the second substrate contact portion each have a plurality of protrusions protruding upward from the central region; the protrusions are arranged at a first density on the first substrate contact portion; An electrostatic chuck, wherein the protrusions are arranged on the second substrate contact portion at a second density that is less than the first density.

2. The electrostatic chuck according to claim 1 , wherein the protrusions of the first substrate contact portion are concentrically arranged with the through hole as a center.

3. an electrostatic electrode for attracting the substrate; The electrostatic chuck according to claim 1 , wherein at least a portion of the first substrate contact portion is located above the electrostatic electrode.

4. The electrostatic chuck according to claim 3 , wherein the first substrate contact portion has an end projection disposed above an end portion of the electrostatic electrode on a through-hole side.

5. The electrostatic chuck of claim 4 , wherein the first substrate contact portion has an inner protrusion disposed radially inward of the through hole relative to the end protrusion.

6. The electrostatic chuck according to claim 5 , wherein the inner protrusions are arranged on the same circumference with the through hole as a center.

7. The electrostatic chuck of claim 4 , wherein the first substrate contact portion has an outer protrusion disposed radially outward of the through hole relative to the end protrusion.

8. The electrostatic chuck according to claim 7 , wherein the outer projections are arranged on the same circumference with the through hole as a center.

9. The through hole is further formed in an annular region for supporting a ring assembly; a first ring contact portion disposed around a through hole formed in the annular region; a second ring contact portion disposed around the first ring contact portion; the first ring contact portion and the second ring contact portion have a plurality of protrusions protruding upward from the annular region; the protrusions are arranged on the first ring contact portion at a third density; 3 . The electrostatic chuck according to claim 1 , wherein the protrusions are arranged on the second ring contact portion at a fourth density that is lower than the third density.

10. The electrostatic chuck according to claim 1 , wherein the through hole is a hole for inserting a lifter pin therethrough.

11. 3. The electrostatic chuck according to claim 1, wherein the through hole is a hole for supplying a heat transfer gas for controlling a temperature of the substrate.

12. The base and an electrostatic chuck provided on an upper portion of the base, The electrostatic chuck comprises: a central region for supporting a substrate; At least one through hole formed in the central region; a first board contact portion disposed around the through hole; a second substrate contact portion disposed around the first substrate contact portion; the first substrate contact portion and the second substrate contact portion each have a plurality of protrusions protruding upward from the central region; the protrusions are arranged at a first density on the first substrate contact portion; The substrate support, wherein the protrusions are arranged on the second substrate contact portion at a second density that is less than the first density.

13. The substrate support according to claim 12 , wherein the protrusions of the first substrate contact portion are arranged concentrically about the through hole.

14. an electrostatic electrode for attracting the substrate; The substrate support according to claim 12 or 13, wherein at least a portion of the first substrate contact portion is located above the electrostatic electrode.

15. The substrate support of claim 14 , wherein the first substrate contact portion has an end protrusion disposed above a through-hole side end of the electrostatic electrode.

16. The substrate support of claim 15 , wherein the first substrate contact portion has an inner protrusion disposed radially inward of the through hole relative to the end protrusion.

17. The substrate support according to claim 16 , wherein the inner protrusions are arranged on the same circumference with the through hole as a center.

18. The substrate support of claim 15 , wherein the first substrate contact portion has an outer protrusion disposed radially outward of the through hole relative to the end protrusion.

19. The substrate support according to claim 18 , wherein the outer protrusions are arranged on the same circumference with the through hole as a center.

20. a plasma processing chamber; a substrate support disposed within the plasma processing chamber; The substrate support includes: The base and an electrostatic chuck provided on an upper portion of the base, The electrostatic chuck comprises: a central region for supporting a substrate; At least one through hole formed in the central region; a first board contact portion disposed around the through hole; a second substrate contact portion disposed around the first substrate contact portion; the first substrate contact portion and the second substrate contact portion each have a plurality of protrusions protruding upward from the central region; the protrusions are arranged at a first density on the first substrate contact portion; The substrate processing apparatus, wherein the protrusions are arranged on the second substrate contact portion at a second density that is lower than the first density.