Method for Controlling Electrostatic Chuck Movement to Prevent Wafer Breakage

Abstract

An apparatus and method for lifting a substrate from a substrate support includes: i. moving the substrate support and the substrate in a first direction from a first position toward a lift pin, the substrate support having through holes each configured to receive a corresponding lift pin, to move the substrate support and the substrate; ii. contacting the substrate with the lift pin while moving the substrate support and the substrate; iii. determining a force applied to the lift pin when contacting the lift pin; iv. comparing the determined force on the lift pin with a predetermined threshold force; v. determining that the force on the lift pin is greater than or equal to the threshold force, and moving the substrate support away from the lift pin in a second direction opposite the first direction.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to methods, systems, and apparatuses for substrate handling, and more particularly, to the removal of substrates from substrate support pedestals.

Background Art

[0002] Physical vapor deposition (PVD) equipment often utilizes a Johnson-Rahbeck (JR) electrostatic chuck (ESC) or a Coulomb ESC to clamp a substrate to a substrate support pedestal for PVD processing. Such chucks rely on electrostatic forces created by opposite charges accumulated on the substrate and the ESC. After PVD processing, a de-chucking process may be performed to remove the accumulated charge and unclamp the substrate, and thus the substrate can be lifted from the ESC and transferred for subsequent processing. However, after such de-chucking, residual electrostatic charges and clamping forces may remain.

[0003] Often, lift pins are used to lift the substrate away from the ESC. Such lift pins can pass through holes in the ESC, contact the back side of the substrate, and apply a force to the substrate to lift it from the ESC. When a clamping force exists on the substrate, a force greater than the clamping force is required to lift the substrate from the ESC. However, if the force applied to the substrate by the lift pin exceeds a certain force, each substrate can be damaged. Thus, if the clamping force remaining on the substrate after de-chucking is greater than that certain force, the force of the lift pin on the substrate will exceed that certain force on the substrate and damage the substrate.

[0004] Accordingly, the inventors have provided embodiments of an improved substrate lift method and system as disclosed herein.

Summary of the Invention

[0005] A method, system, and non-transitory machine-readable storage medium for lifting a substrate from a substrate support are provided herein.

[0006] In some embodiments, a method of lifting a substrate from a substrate support includes: i. moving the substrate support and the substrate in a first direction from a first position toward a lift pin, wherein the substrate support has through holes each configured to receive a corresponding lift pin, and moving the substrate support and the substrate; ii. contacting the substrate with the lift pin while moving the substrate support and the substrate; iii. determining a force applied to the lift pin when contacting the lift pin; iv. comparing the determined force on the lift pin with a predetermined threshold force; v. determining that the force on the lift pin is equal to or greater than the threshold force, and moving the substrate support in a second direction opposite the first direction away from the lift pin.

[0007] In some embodiments, a substrate lift system for controlling the lifting of a substrate includes a substrate support configured to support the substrate and move vertically between a first position and a release position, the substrate support having through holes; a lift pin configured to pass through the through holes and contact the substrate supported by the substrate support; a motor coupled to the lift pin and configured to vertically position the lift pin; and a force feedback system configured to measure the application of force by the lift pin to the substrate and return the substrate support to the first position if the measured force on the lift pin is equal to or greater than a threshold force.

[0008] In some embodiments, a non-transitory machine-readable storage medium storing processor-executable instructions for causing a machine to implement a method of lifting a substrate from a substrate support is provided, the method comprising: i. moving a substrate support and a substrate in a first direction from a first position toward lift pins, the substrate support having through holes each configured to receive a corresponding lift pin, and moving the substrate support and the substrate; ii. contacting the substrate with the lift pins while moving the substrate support and the substrate; iii. determining a force applied to the lift pins when contacting the lift pins; iv. comparing the determined force on the lift pins with a predetermined threshold force; and v. determining that the force on the lift pins is equal to or greater than the threshold force, and moving the substrate support away from the lift pins in a second direction opposite the first direction.

[0009] Other and further embodiments of the present disclosure are described below.

[0010] Embodiments of the present disclosure, briefly summarized above and described in more detail below, may be understood by reference to the exemplary embodiments of the present disclosure shown in the accompanying drawings. However, since the present disclosure may admit of other equally effective embodiments, the accompanying drawings illustrate only general embodiments of the present disclosure and should not be regarded as limiting of scope.

Brief Description of the Drawings

[0011]

Figure 1A

Figure 1B

Figure 2

Figure 3

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Figure 8

DETAILED DESCRIPTION OF THE INVENTION

[0012] For ease of understanding, where possible, the same reference numbers are used to designate identical elements common to the figures. The figures are not drawn to scale and may be simplified for clarity. Elements and features of one embodiment may be beneficially incorporated into other embodiments without further recitation.

[0013] Embodiments of a method, system, and non-transitory machine-readable storage medium for lifting a substrate from a substrate support are provided herein.

[0014] As described in more detail below, in some embodiments, closed-loop control is used to prevent damage to the substrate. More specifically, in some embodiments, such closed-loop control uses a lift pin driver response (motor torque or motor position) to control the application of force to the substrate by the lift pins. The use of lift pin driver response advantageously does not require modification of the existing process chamber by additional sensors or instrumentation, such as strain gauges, which often fail under substrate processing conditions. Instead, as described above, many process chambers already include some form of open-loop motorized lift pins and substrate support control, which can be upgraded to closed-loop control while maintaining process compatibility.

[0015] FIG. 1A is a schematic diagram of a system 100 for lifting a substrate 102 from a substrate support 104, according to an embodiment of the present disclosure. In some embodiments, the system 100 can be disposed inside a chamber 106 that can be maintained at a vacuum.

[0016] In some embodiments, and as shown in FIG. 1A, system 100 may include a substrate support 104 configured to support a substrate 102 and move vertically between a first position 108 and a release position 110. In some embodiments, substrate support 104 may include an ESC and may have a through hole 112. Substrate support 104 may be connected to a motor 126 configured to lift and lower substrate support 104 in chamber 106. In some embodiments, and as shown in FIG. 1, system 100 may include lift pins 114 configured to pass through through hole 112 and contact substrate 102 supported by substrate support 104. In some embodiments, and as shown in FIG. 1A, lift pins 114 may be connected to a hoop 116 to enable all of lift pins 114 to be lifted and lowered together. In some embodiments, the lift pins may be grounded (e.g., through hoop 116) and configured to discharge some residual charge on substrate 102 through lift pins 114 when contacting lift pins 114.

[0017] In some embodiments, and as shown in FIG. 1A, system 100 may include a motor 118 coupled to lift pins 114 and configured to vertically position lift pins 114 in chamber 106. In some embodiments, motor 118 may be a servo motor or a stepper motor. Also, in some embodiments, system 100 may include a motor encoder 122 configured to measure a motor position corresponding to the vertical position of lift pins 114. In some embodiments, motor encoder 122 and motor 118 may be connected to a motor driver 124, such as an Ether-CAT (also known as "ECAT") motor driver, configured to measure and output both motor position changes and motor torque. Thus, motor driver 124 may be configured as a torque measurement device and a position measurement device.

[0018] In some embodiments, and as shown in FIG. 1A, system 100 may include at least one controller 120 coupled to motor 118 (via motor driver 124) and coupled to substrate support 104 (via motor 126). In some embodiments, motor driver 124 may be incorporated into controller 120. In some embodiments, controller 120 is configured to control the relative movement and relative position between substrate support 104 and lift pin 114. In some embodiments, controller 120 may be configured to move substrate support 104 towards lift pin 114 and maintain the static vertical position of lift pin 114 while causing contact between substrate 102 and lift pin 114. In some embodiments, controller 120 may be configured to maintain the static vertical position of substrate support 104 while moving lift pin 114 towards substrate support 104 and substrate 102.

[0019] In some embodiments, controller 120 is configured to determine the force applied to lift pin 114 by substrate 102 (which is equal to the electrostatic clamping force on substrate 102), compare the determined force on lift pin 114 to a predetermined threshold force, and lift substrate support 104 to a first position 108 if the determined force on lift pin 114 is greater than or equal to the threshold force. The force applied to lift pin 114 by substrate 102 is equal to the remaining electrostatic force (i.e., clamping force) on substrate 102.

[0020] In some embodiments, if the determined force on lift pin 114 from substrate 102 is less than the threshold force, controller 120 may continue to move substrate support 104 in a first direction to a release position 110, causing lift pin 114 to lift substrate 102 away from substrate support 104.

[0021] In some embodiments, the threshold force can be set to the substrate damage limit. Thus, a force applied to the substrate at or above the substrate damage limit will cause damage to the substrate, and a force applied to the substrate below the substrate damage limit will not cause damage to the substrate. In some embodiments, the threshold force can be based on characteristics of the substrate, such as the mechanical properties (e.g., yield strength) and electrical properties (e.g., conductivity) of substrate 102.

[0022] FIG. 1B schematically shows the forces acting on lift pin 114 in various states of the substrate lift process according to the present disclosure. In FIG. 1B, the weight of substrate 102 is considered negligible. In some embodiments, and as shown in FIG. 1B, the pressure in chamber 106 is maintained at a vacuum, which exposes lift pin 114 to a vacuum force F vacuum At a first time T1, lift pin 114 is controlled by motor 118 to remain stationary relative to chamber 106, and lift pin 114 is not in contact with substrate 102. At the first time T1, the force F motor,1 of motor 118 acting on lift pin 114 keeps lift pin 114 stationary and is equal to the vacuum force F vacuum As will be described in more detail below, at a second time T2 after T1, substrate 102 can be lowered by substrate support 104 to contact lift pin 114, and if there is remaining charge on substrate 102 (i.e., there is a clamping force on substrate 102), the vacuum force F vacuum will be equal to the sum of the electrostatic force F electrostatic and the motor force F motor,2 at time T2. Thus, when the vacuum force F vacuum in the chamber remains constant from T1 to T2, the electrostatic force F electrostatic will be equal to the difference between the motor force F motor,1 at time T1 and the motor force F motor,2 at time T2, both of which can be obtained from measurements of motor torque or lift pin displacement, as described below. Also, the motor force F motor,1and the difference between the motor force F at time T2 motor,2 is zero, the electrostatic force F electrostatic will be zero.

[0023] In some embodiments, the controller 120 is configured to determine the force applied to the lift pin 114 by the substrate 102 based on a measurement of the motor torque when the motor 118 maintains the static vertical position of the lift pin 114 in the chamber 106. For example, the motor torque can be considered equivalent to the product of the resultant force on the motor and the moment arm, which is a fixed value based on the physical configuration of the motor and the lift pin 114.

[0024] In another embodiment, the force applied to the lift pin 114 by the substrate 102 can be determined based on measuring the vertical movement of the lift pin 114 upon contact with the substrate 102. For example, a change in the motor position, as measured by the motor encoder 122, can be used to determine a change in the vertical position of the lift pin 114. The controller 120 can correlate the determined change in the vertical position of the lift pin 114 to the force acting on the motor 118.

[0025] For example, in some embodiments, while the lift pin 114 is controlled to be maintained in the static vertical position, upon contact between the lift pin 114 and the substrate 102, the electrostatic force F Electrostatic makes the balanced force between F vacuum on the lift pin 114 and F motor unbalanced. As a result of the force imbalance on the lift pin 114, the electrostatic force F Electrostatic vertically (e.g., downward) moves the lift pin 114, and the electrostatic force F ElectrostaticThe distance based on the size of [[ID=]] can be displaced. The change in the vertical position of the lift pin 114 can be compared with a configurable threshold that can correspond to a threshold force. If the change in the vertical position of the lift pin 114 is greater than or equal to the threshold, the lift pin 114 and the substrate 102 can be separated to avoid applying a force exceeding the threshold to the substrate 102. Otherwise, if the change in the vertical position of the lift pin 114 is less than the threshold, the substrate support 104 and the substrate 102 can be moved (e.g., pulled down) to the release position 110, where the lift pin 114 can cause the substrate 102 to be lifted from the substrate support 104.

[0026] Figures 2-7 relate to a method 700 of lifting a substrate 102 according to an embodiment of the present disclosure, using, for example, the system 100 described above. In some embodiments, and as shown in FIG. 7, the method 700 can begin at 701, where, for example, as shown in FIG. 2, the substrate 102 is supported at a first position 108 by a substrate support 104, where the substrate 102 is vertically spaced from the lift pin 114. Since the lift pin 114 is not in contact with the substrate 102, the determined force applied to the lift pin by the substrate 102 is 0, as indicated by the indicator 202 in FIG. 2. The force applied to the lift pin 114 can be determined as described above.

[0027] At 702, the substrate support 104 and the substrate 102 are vertically moved in the chamber 106 from the first position 108 in the first direction (e.g., downward) towards the lift pin 114 as shown in FIG. 2 by the downward arrow 206. In some embodiments, the controller 120 controls the motor 118 to maintain the lift pin 114 at a certain vertical position with respect to the chamber 106. At 703, at some point in the movement of the substrate support 104 and the substrate 102 between the first position and the release position, the substrate 102 contacts the lift pin 114. At 704, when the lift pin 114 is brought into contact with the substrate 102, the force applied to the lift pin 114 is determined. In the example shown in FIG. 3, the determined force shown on the indicator 202 is equal to the threshold force represented by the indicator 204.

[0028] At 705, the determined force on the lift pin is compared with a predetermined threshold force. If the determined force on the lift pin 114 is greater than or equal to the threshold force (at 706, yes), the substrate support 104 and the substrate 102 are moved away from the lift pin 114 in the second direction opposite to the first direction as shown by the arrow 306 in FIG. 3. At 707, the substrate support 104 can be returned to the first position, for example as shown in FIG. 4, and then the substrate 102 may go through a de-chucking process at 708 to remove residual charge on the substrate 102 and reduce the clamping force on the substrate 102. After such a de-chucking process, the method 700 can repeat 702 - 706 as shown in FIGS. 4 and 5 until the determined force on the lift pin 114 becomes less than the threshold force (at 706, no).

[0029] If the determined force on the lift pin 114 is less than the threshold force (No in 706), in 709, the substrate support 104 and the substrate 102 continue to move in the first direction to the release position 110 as shown in FIG. 6, and the lift pin can cause the substrate 102 to be lifted away from the substrate support 104. As shown in FIG. 6, the determined force indicated at the indicator 202 is less than the threshold force 304. In 710, the method 700 can end, and then the substrate 102 can be transferred to another chamber connected to the chamber 106 for additional substrate processing.

[0030] Accordingly, embodiments of the methods and systems described herein provide closed-loop feedback control that examines whether the clamping force on the substrate is less than a threshold force that could damage the substrate when applied by the lift pins. Repeated de-chucking can be performed to reduce the clamping force to a level below the threshold force to enable safe lifting of the substrate from the ESC. As a result, embodiments of the methods and systems described herein can improve substrate yield and process throughput.

[0031] Various embodiments of the method of lifting a substrate can be implemented on one or more computer systems that can interact with various other devices as described herein. One such computer system is the computer system 800 shown by FIG. 8, and the computer system 800 can implement any of the elements or functionality shown in FIGS. 1A and 2-7 in various embodiments. For example, the computer system 800 can be utilized in various embodiments of the present disclosure to implement the controller 120 according to one or more embodiments.

[0032] In various embodiments, computer system 800 may be configured to implement method 700 as described above. Computer system 800 may be used to implement any other system, device, element, functionality, or method of the embodiments described above. In the illustrated embodiment, computer system 800 may be configured to implement method 700 as processor-executable program instructions 822 (e.g., program instructions executable by one or more processors 810) in various embodiments.

[0033] In the illustrated embodiment, computer system 800 includes one or more processors 810a - 810n coupled to system memory 820 via an input / output (I / O) interface 830. Computer system 800 further includes a network interface 840 coupled to I / O interface 830 and one or more input / output devices 850 such as a cursor control device 860, a keyboard 870, and one or more displays 880. Network interface 840 may be connected to a communication network 890. In various embodiments, any of the components may be utilized by computer system 800 to receive the user input described above. In various embodiments, a user interface may be generated and displayed on display 880. In some cases, an embodiment may be implemented using a single instance of computer system 800, but in other embodiments, multiple such systems, or multiple nodes that create computer system 800, may be configured to host different portions or instances of the various embodiments. For example, in one embodiment, some elements may be implemented via one or more nodes of computer system 800 that are separate from the nodes implementing other elements. In another example, multiple nodes may implement computer system 800 in a distributed fashion.

[0034] In different embodiments, the computer system 800 can be any of a variety of types of devices, including, but not limited to, a personal computer system, a desktop computer, a laptop, notebook, tablet or netbook computer, a mainframe computer system, a handheld computer, a workstation, a network computer, a mobile device, a consumer device, an application server, a storage device, a switch, a modem, a router, or any other peripheral device, or generally any type of computing or electronic device.

[0035] In various embodiments, the computer system 800 can be a uniprocessor system including one processor 810, or a multiprocessor system including several processors 810 (e.g., two, four, eight, or another suitable number). The processor 810 can be any suitable processor capable of executing instructions. For example, in various embodiments, the processor 810 can be a general-purpose processor or an embedded processor implementing any of a variety of instruction set architectures (ISAs). In a multiprocessor system, each of the processors 810 can, but typically does not necessarily, implement the same ISA.

[0036] System memory 820 may be configured to store program instructions 822 and / or data 832 accessible by processor 810. In various embodiments, system memory 820 may be implemented using any suitable memory technology, such as static random access memory (SRAM), synchronous dynamic RAM (SDRAM), non-volatile / flash type memory, or any other type of memory. In the illustrated embodiment, program instructions and data implementing any of the elements of the embodiments described above may be stored within system memory 820. In other embodiments, program instructions and / or data may be received, sent, or stored on different types of computer-accessible media, or on similar media separate from system memory 820 or computer system 800.

[0037] In one embodiment, I / O interface 830 may be configured to coordinate I / O traffic between processor 810 and any peripheral devices within the device, including system memory 820 and other peripheral interfaces such as network interface 840 or input / output device 850. In some embodiments, I / O interface 830 may perform any necessary protocol, timing, or other data conversions to convert data signals from one component (e.g., system memory 820) into a format suitable for use by another component (e.g., processor 810). In some embodiments, I / O interface 830 may include support for devices attached through various types of peripheral buses, such as variations of the peripheral component interconnect (PCI) bus standard or the universal serial bus (USB) standard. In some embodiments, the functionality of I / O interface 830 may be split among two or more other components, such as a north bridge and a south bridge. Also, in some embodiments, some or all of the functionality of I / O interface 830, such as the interface to system memory 820, may be incorporated directly into processor 810.

[0038] Network interface 840 can be configured to enable data to be exchanged between computer system 800 and other devices attached to a network, such as one or more external systems, or between nodes of computer system 800. In various embodiments, communication network 890 can include one or more networks including, but not limited to, a local area network (LAN) (e.g., Ethernet or corporate network), a wide area network (WAN) (e.g., the Internet), a wireless data network, any other electronic data network, or some combination thereof. In various embodiments, network interface 840 can support communication via, for example, a wired or wireless general data network such as any suitable type of Ethernet network, a digital fiber communication network, a storage area network such as Fibre Channel SAN, or via any other suitable type of network and / or protocol.

[0039] Input / output device 850 can include, in some embodiments, one or more display terminals, keyboards, keypads, touch pads, scanning devices, voice or optical recognition devices, or any other device suitable for entering or accessing data by one or more computer systems 800. Multiple input / output devices 850 can be present within computer system 800 or distributed across various nodes of computer system 800. In some embodiments, similar input / output devices can be separate from computer system 800 and can interact with one or more nodes of computer system 800 through a wired or wireless connection, such as via network interface 840.

[0040] Those skilled in the art will understand that the computer system 800 is merely exemplary and does not limit the scope of the embodiments. In particular, the computer system and devices may include any combination of hardware or software capable of implementing the functions shown in the various embodiments. The computer system 800 may also be connected to other devices not shown or, alternatively, may operate as a stand-alone system. Further, the functionality provided by the components shown may, in some embodiments, be combined in fewer components or distributed among additional components. Similarly, in some embodiments, some of the functionality of the components shown may not be provided and / or other additional functionality may be available.

[0041] Also, while various items are shown as being stored in memory or storage while in use, those skilled in the art will appreciate that these items or portions of those items may be transferred between memory and other storage devices for memory management and data integrity purposes. Alternatively, in other embodiments, some or all of the software components execute in memory on another device and communicate with the illustrated computer system via inter-computer communication. Also, some or all of the system components or data structures may be stored (e.g., as instructions or structured data) on a computer-accessible medium or portable article to be read by an appropriate drive, and various examples of which were described above. In some embodiments, instructions stored on a computer-accessible medium separate from computer system 800 may be transmitted to computer system 800 via a transmission medium or signal, such as an electrical signal, electromagnetic signal, or digital signal, transmitted via a communication medium such as a network and / or wireless link. Various embodiments may further include receiving, sending, or storing instructions and / or data implemented according to the above description on a computer-accessible medium or via a communication medium. Generally, computer-accessible media may include magnetic or optical media, such as storage media or memory media, such as volatile or non-volatile media such as disks or DVD / CD-ROMs, RAM (e.g., SDRAM, DDR, RDRAM, SRAM, etc.), ROM, etc.

[0042] Embodiments according to the present disclosure may be implemented in hardware, firmware, software, or any combination thereof. Embodiments may also be implemented as instructions stored on one or more machine-readable media, which may be read and executed by one or more processors. A machine-readable media may include any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computing device, or a "virtual machine" running on one or more computing devices). For example, a machine-readable media may include any suitable form of volatile or non-volatile memory.

[0043] Modules, data structures, etc. defined herein are defined as such for ease of explanation and do not imply that specific implementation details are required. For example, any of the modules and / or data structures described may be combined or divided into sub-modules, sub-processes, or other units of computer code or data as may be required by a particular design or implementation.

[0044] The above are directed to embodiments of the present disclosure, but other and further embodiments of the present disclosure may be devised without departing from its basic scope.

Claims

Claim 1 A method of lifting a substrate from a substrate support, comprising: i. moving the substrate support and the substrate in a first direction from a first position towards lift pins, the substrate support having through holes each configured to receive a corresponding lift pin, and moving the substrate support and the substrate; ii. contacting the substrate with the lift pins while moving the substrate support and the substrate; iii. determining a force applied to the lift pins when contacting the lift pins; iv. comparing the determined force on the lift pins with a predetermined threshold force; v. determining that the force on the lift pins is equal to or greater than the threshold force, and moving the substrate support away from the lift pins in a second direction opposite to the first direction. A method comprising the above steps. Claim 2 The method according to claim 1, further comprising repeating i. to iv. until the determined force on the lift pins is less than the threshold force. Claim 3 The method according to claim 2, further comprising performing a dechucking process on the substrate each time i. to iv. are repeated. Claim 4 The method according to any one of claims 1 to 3, further comprising determining that the force on the lift pins is less than the threshold force, continuing to move the substrate support in the first direction to a release position, and causing the lift pins to lift the substrate away from the substrate support. Claim 5 The method according to any one of claims 1 to 3, wherein determining the force comprises measuring a motor torque of a motor that controls a static position of the lift pins. Claim 6 The method according to any one of claims 1 to 3, wherein determining the force comprises measuring a change in position of the lift pins when the substrate is contacted with the lift pins. Claim 7 The method according to claim 6, wherein measuring the change in position comprises measuring a motor position of a motor that controls a static position of the lift pins. Claim 8 The method according to any one of claims 1 to 3, wherein the threshold force is based on one or more characteristics of the substrate. Claim 9 A substrate lift system for controlling the lifting of a substrate, a substrate support configured to support the substrate and move vertically between a first position and a release position, the substrate support having a through hole; a lift pin configured to pass through the through hole and contact the substrate supported by the substrate support; a motor coupled to the lift pin and configured to vertically position the lift pin; a force feedback system configured to determine a force applied to the lift pin by the substrate and, when the determined force is greater than or equal to a threshold force, return the substrate support to the first position A substrate lift system comprising: **Claim 10** The system according to claim 9, wherein the force feedback system, when the determined force is less than the threshold force, moves the substrate support in a first direction to the release position, causing the lift pin to pass through the through hole and causing the substrate to lift away from the substrate support. **Claim 11** The force feedback system is a torque measurement device for measuring the motor torque of the motor when the substrate contacts the lift pin; a controller for controlling the vertical movement of the substrate support based on the measured motor torque The system according to claim 9, comprising: **Claim 12** The system according to claim 11, wherein the controller is configured to determine the force based on the measured motor torque and, when the determined force is greater than or equal to the threshold force, lift the substrate support away from the lift pin. **Claim 13** The force feedback system is an encoder configured to detect a motor position corresponding to the position of the lift pin; a controller for controlling the vertical movement of the substrate support based on a change in the detected motor position when the substrate contacts the lift pin The system according to claim 9, comprising: **Claim 14** The system according to claim 13, wherein the controller is configured to determine the force based on the change in the detected motor position, and when the determined force is greater than or equal to the threshold force, lift the substrate support away from the lift pin.

15. The system according to claim 9, wherein the force feedback system includes at least one controller coupled to the motor and the substrate support, the controller being configured to move the substrate support towards the lift pin, maintain the vertical position of the lift pin while causing contact between the substrate and the lift pin, determine the force applied to the lift pin by the substrate, compare the determined force on the lift pin with a predetermined threshold force, and lift the substrate support to the first position when the determined force on the lift pin is greater than or equal to the threshold force.

16. A non-transitory machine-readable storage medium storing processor-executable instructions for causing a machine to implement a method of lifting a substrate from a substrate support, the method comprising: i. moving the substrate support and the substrate from a first position towards the lift pin in a first direction, the substrate support having through holes each configured to receive a corresponding lift pin, and moving the substrate support and the substrate; ii. contacting the substrate with the lift pin while moving the substrate support and the substrate; iii. determining the force applied to the lift pin when contacting the lift pin; iv. comparing the determined force on the lift pin with a predetermined threshold force; v. determining that the force on the lift pin is greater than or equal to the threshold force, and moving the substrate support away from the lift pin in a second direction opposite to the first direction. A non-transitory machine-readable storage medium including the above.

17. The non-transitory machine-readable storage medium according to claim 16, wherein the method further includes repeating i. to iv. until the determined force on the lift pin is less than the threshold force.

18. The non - transitory machine - readable storage medium according to claim 17, wherein the method further includes performing a de - chucking process on the substrate each time i. to iv. are repeated.

19. The non - transitory machine - readable storage medium according to any one of claims 16 to 18, wherein the method further includes determining that the force on the lift pin is less than the threshold force, and continuing to move the substrate support in the first direction to a release position, causing the lift pin to lift the substrate away from the substrate support.

20. Determining the force comprises measuring a change in the motor torque of a motor that controls a static position of the lift pin when in contact between the lift pin and the substrate, and determining the force based on the change in the motor torque, or measuring a change in the position of the lift pin from a change in the motor position when the lift pin is in contact with the substrate, and determining the force based on the change in the motor position The non - transitory machine - readable storage medium according to any one of claims 16 to 18.

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