Spindle assembly for wafer transfer in multi-station processing modules

Abstract

A spindle assembly for transferring wafers in a multi-station processing module is provided, comprising: a hub body configured to rotate around a central axis; a plurality of end effectors, each end effector having a first end configured to be connected to the hub body and a second end configured to support the wafer; a plurality of covers; and a plurality of fastener assemblies; wherein the first end of each end effector is clamped between a corresponding cover and a corresponding outer portion of the hub body by a corresponding fastener assembly, and the corresponding fastener assembly includes a wave spring that provides a consistent clamping force.

Description

Technical Field

[0001] Embodiments of the present invention relate to structures used in semiconductor processing tools, and in particular, to spindle assemblies for supporting and transferring semiconductor wafers in multi-station processing modules. Background Art

[0002] In wafer processing, a processing module may have multiple processing stations, such as in a four-station processing module manufactured by Lam Research Corporation. Such a multi-station processing module may use a spindle assembly to transfer wafers from one station to another. In general, such a spindle assembly includes a plurality of paddles extending from a central hub, wherein the paddles support the wafer during transfer.

[0003] It is in this context that the implementation of the present disclosure emerges. Summary of the invention

[0004] Implementations of the present disclosure provide systems, apparatus, and methods that employ a spindle assembly that supports wafers during transfer in a multi-station processing module.

[0005] A spindle assembly is disclosed that prevents loosening of components used to attach a ceramic end effector to a spindle hub.

[0006] Existing designs use only fasteners to clamp the end effector, which can loosen due to high operating temperatures. However, according to implementations of the present disclosure, a spindle assembly is provided that uses a barrel nut with a wave spring to decouple fastener torque from clamping force and provide an order of magnitude higher thermal expansion compliance. Disclosed herein is a novel use of a wave spring and interlocking geometry to secure a ceramic end effector, thereby enabling much higher operating temperatures with lower maintenance intervals that existing designs require to re-torque loose fasteners.

[0007] Other aspects and advantages of the present invention will become apparent from the following detailed description, taken in conjunction with the accompanying drawings, illustrating by way of example the principles of the invention. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] Figure 1A A perspective view of a spindle assembly according to an implementation of the present disclosure is shown.

[0009] Figure 1B A radial cross-sectional view of a portion of a spindle assembly 100 is shown in accordance with implementations of the present disclosure.

[0010] Figure 2A A perspective view of the hub body 102 and cover 106a is shown, and a fastener assembly is further shown, in accordance with an implementation of the present disclosure.

[0011] Figure 2B A close-up cross-sectional view showing the fastener assembly 108a when installed is shown in accordance with an implementation of the present disclosure.

[0012] Figure 2C A transverse cross-sectional view of a portion of a spindle assembly is shown in accordance with implementations of the present disclosure.

[0013] Figure 2D A transverse cross-sectional view of a portion of a spindle assembly is shown in accordance with implementations of the present disclosure.

[0014] Figure 3 A perspective view of a hub body 102 is shown in accordance with an implementation of the present disclosure.

[0015] Figure 4A A top view of cover 106a is shown in accordance with an implementation of the present disclosure.

[0016] Figure 4B A side view of a cover 106a is shown in accordance with an implementation of the present disclosure.

[0017] Figure 4C A bottom view of the cover 106a is shown in accordance with an implementation of the present disclosure.

[0018] Figure 5 A perspective view of a barrel nut is shown in accordance with an implementation of the present disclosure.

[0019] Fig. 6A A perspective view of a wave spring is shown in accordance with an implementation of the present disclosure.

[0020] Figure 6B A top view of a wave spring according to an implementation of the present disclosure is shown.

[0021] Figure 6C A side view of a wave spring according to an implementation of the present disclosure is shown.

[0022] Fig. 7A A perspective view of a fender washer according to an implementation of the present disclosure is shown.

[0023] Figure 7B A top view of a fender washer according to an implementation of the present disclosure is shown.

[0024] Figure 7C A side view of a fender washer according to an implementation of the present disclosure is shown.

[0025] Fig. 8A A cross-sectional perspective view of a hub body according to an implementation of the present disclosure is shown.

[0026] Figure 8BAn enlarged perspective view of components of a spindle fastener assembly according to implementations of the present disclosure is shown.

[0027] Fig. 9A A top view of a hub body 102 is shown in accordance with an implementation of the present disclosure.

[0028] Fig. 9B An enlarged top view of a through hole 900a according to an implementation of the present disclosure is shown.

[0029] Fig. 9C A bottom view of the hub body 102 is shown in accordance with an implementation of the present disclosure.

[0030] Fig.9D An enlarged bottom view of a central portion of the hub body 102 is shown in accordance with an implementation of the present disclosure.

[0031] Fig.10 A cross-sectional view of a substrate processing system 1100 ′ engaging multiple stations according to implementations of the present disclosure is shown.

[0032] Fig.11A A top view of a multi-station substrate processing system 1100' is shown in accordance with an implementation of the present disclosure, wherein four processing stations are provided in a processing chamber.

[0033] Fig. 11B A schematic diagram of an embodiment of a multi-station substrate processing system with inbound load locks and outbound load locks according to implementations of the present disclosure is shown.

[0034] Fig.12 A control module 1600 for controlling the system of the present disclosure according to an implementation of the present disclosure is shown. DETAILED DESCRIPTION

[0035] Embodiments of the present disclosure provide various details of a spindle assembly used in a processing chamber. The spindle assembly can be used in a processing chamber that includes multiple stations for processing, including multiple pedestals or chucks. In one configuration, if the processing chamber includes a set of pedestals, the spindle assembly will have an equal number of end effectors so that the system can transfer all wafers at the same time, such as by a rotating assembly. In this way, all wafers are transferred to different pedestals so that they can be further processed in the processing chamber. It should be understood that embodiments of the present invention can be implemented in a variety of ways, such as processes, devices, systems, equipment, or methods. Several embodiments are described below.

[0036] A wafer processing system includes one or more chambers or "reactors" suitable for wafer processing. Each chamber may include multiple stations to accommodate one or more wafers for processing. One or more chambers hold the wafers in one or more defined positions (with or without motion, such as rotation, vibration or other agitation within the position). Wafers undergoing processing (e.g., deposition, etching, cleaning, etc.) can be transferred in and out of the reactor chamber during processing and from one station to another within the reactor chamber. Of course, processing can occur entirely at a single station, or any portion of the processing can be performed at any number of stations.

[0037] Figure 1A A perspective view of a spindle assembly 100 according to an implementation of the present disclosure is shown. The spindle assembly 100 includes a hub body 102 to which a number of end effectors 104a, 104b, 104c, and 104d are attached. When attached, the end effectors radiate outward from the hub body 102. The end effectors support wafers within a multi-station processing module and are used to lift and transfer wafers from one station to another. Although there are specifically four end effectors in the implementation of the spindle assembly shown, it should be understood that there may be one or two or more end effectors in other implementations. For ease of description throughout the present disclosure, components are described with respect to specific portions or end effectors of the spindle assembly, and it should be understood that this also applies to corresponding other portions or end effectors of the spindle assembly. Therefore, it should be understood that components / configurations are repeatedly provided to enable configuration of a spindle assembly with a given number of end effectors, but for the sake of brevity, these repeated components / configurations may not all be specifically described or shown.

[0038] When the cover is fastened to the hub body, the end effectors 104a, 104b, 104c, and 104d are secured to the hub body 102 by the covers 106a, 106b, 106c, and 106d, respectively. That is, when the cover is fastened to the hub body by the fastener assembly, each end effector is clamped between the hub body 102 and the corresponding cover. For example, in the illustrated implementation, the cover 106a is secured to the hub body 102 by the fastener assemblies 108a and 108b, thereby clamping the end effector 104a in place between the hub body 102 and the cover 106a.

[0039] Figure 1BA radial cross-sectional view of a portion of a spindle assembly 100 according to an implementation of the present disclosure is shown. In the illustrated implementation, a radial cross-sectional portion including a cover 106a and an end effector 104 is shown. As shown, the inner end of the end effector 104a is clamped between the cover 106a and the lower portion of the hub body 102. An undercut portion 110 of the hub body is also shown, which forms a groove or recess or groove into which a lip 112 of the cover 106a fits. This fitting, which is similar to a tongue-and-groove type mechanism, vertically secures the inner end of the cover 106a to the hub body 102, thereby enabling clamping of the end effector 104a.

[0040] Figure 2A A perspective view of a hub body 102 and a cover 106a according to an implementation of the present disclosure is shown, and a fastener assembly is further shown. Fastener assemblies 108a and 108b are shown, each including several components for securing the cover 106a to the hub body 102. Fastener assembly 108a includes a barrel nut 200a, a wave spring 202a, a fender washer 204a, a Belleville washer 206a, and a screw 208a that is screwed into the barrel nut 200a. Fastener assembly 108b includes a barrel nut 200b, a wave spring 202b, a fender washer 204b, a Belleville washer 206b, and a screw 208b that is screwed into the barrel nut 200b.

[0041] The barrel nut 200a extends through a through hole 210a in the cover 106a and a corresponding through hole 212a in the hub body 102. The barrel nut 200b extends through a through hole 210b in the cover 106a and a corresponding through hole 212b in the hub body 102.

[0042] Although cover 106a and its associated fastener assembly are shown in detail, it should be understood that other covers are secured in a similar manner by corresponding fastener assemblies. For example, cover 106b is secured to hub body 102 by a fastener assembly including barrel nuts 200c and 200d.

[0043] Figure 2B A close-up transverse cross-sectional view of a fastener assembly 108a showing installation is shown according to an implementation of the present disclosure. As shown, a wave spring 202a is mounted around the lower end of the shaft of a barrel nut 200a. The wave spring 202a applies force to a fender washer 204a, effectively pulling the barrel nut 200a downward and securing the cover 106a. Of course, a similar mechanism is provided for the fastener assembly 108b.

[0044] Therefore, the cover 106a is keyed into the hub body 102 and clamped by the wave spring. This decouples the clamping force on the end effector (paddle) from the fastener torque.

[0045] Additionally, in some implementations, the barrel nut, wave spring, fender washer, and Belleville washer are all made of the same material, such as Inconel (e.g., Inconel 625 in some implementations.) This eliminates CTE (coefficient of thermal expansion) differences in the fastener stack.

[0046] The present assembly allows full torqueing of the fastener (eg, about 35 in-lbf (about 4 nm) for Inconel 625).

[0047] The wave spring provides a large amount of compliance for CTE differences (e.g., about 0.005 inches (about 0.013 centimeters) and tolerance stack-ups (e.g., about 0.050 inches (about 0.13 centimeters).

[0048] The Inconel fastener stack eliminates all relative axial movement due to CTE differences (due to dissimilar materials). This solves the problem of fastener loosening due to thread shearing caused by material expansion.

[0049] The clearance around the fastener stack in the hub body allows for lateral movement of the cover / clamp due to thermal expansion (due to temperature differences between the body cover / clamp). This solves the problem of fastener loosening through lateral joint movement.

[0050] The wave spring provided provides a consistent clamping force that is separate from the clamping force of the fastener. This solves the problem of fastener loosening due to thread shearing caused by the fastener clamping force.

[0051] Figure 2C A transverse cross-sectional view of a portion of a spindle assembly according to an implementation of the present disclosure is shown. The cross-section shown is vertically through fastener assemblies 108a and 108b, and further illustrates cap 106a, end effector 104a, and hub body 102. Specifically, the bearing surface is shown.

[0052] Figure 2D A transverse cross-sectional view of a portion of a spindle assembly according to an implementation of the present disclosure is shown. The cross-section shown is vertically through the fastener assemblies 108a and 108b, and further shows the cover 106a, the end effector 104a, and the hub body 102. In particular, thermal expansion clearances around the barrel nuts 200a and 200b are shown. These provide tolerance for thermal expansion, such as the thermal expansion of the cover 106a.

[0053] Figure 3A perspective view of a hub body 102 according to an implementation of the present disclosure is shown. As shown, the hub body 102 includes a recess 300a configured to receive the inner end of the end effector 104a. Similarly, a recess is provided for each end effector, such as recess 300b configured to receive the inner end of the end effector 104b. Each recess is a recessed cutout along the top surface of the hub body, and its shape conforms to the shape of the inner / proximal end of the end effector.

[0054] The recess includes relief (eg, reliefs 302a, 302b, 302c) to reduce sticking of the proximal end of the end effector in the hub body 102 after cooling. As shown, the relief reduces the area around the recess that contacts the end effector, thereby reducing sticking.

[0055] Also shown is an undercut 110 which, as described above, provides a recess for locking cover 106a.

[0056] Figure 4A A top view of a cover 106a according to an implementation of the present disclosure is shown. As shown, a lip 112 is included that fits into an undercut 110 of the hub body.

[0057] Figure 4B A side view of a cover 106a according to an implementation of the present disclosure is shown. As shown, the underside of the lip 112 is beveled to make it easier to fit the cover 106a into the undercut 110 of the hub body.

[0058] Figure 4C A bottom view of the cover 106a is shown in accordance with an implementation of the present disclosure.

[0059] Figure 5 A perspective view of a barrel nut according to an implementation of the present disclosure is shown. Inconel barrel nuts are used to create all-Inconel fastener assemblies to eliminate CTE differences. In some implementations, the barrel nut contains Inconel 625.

[0060] Fig. 6A A perspective view of a wave spring according to an implementation of the present disclosure is shown. The wave spring is used to provide clamping load on the end effector and comply with system requirements to mitigate CTE and tolerance stack-up. In some implementations, the wave spring comprises Inconel X-750, Spring Temper.

[0061] Figure 6B A top view of a wave spring according to an implementation of the present disclosure is shown.

[0062] Figure 6C A side view of a wave spring according to an implementation of the present disclosure is shown.

[0063] Fig. 7A A perspective view of a fender washer according to an implementation of the present disclosure is shown. The fender washer is used to create an all-Inconel fastener assembly to eliminate CTE differences. In some implementations, the fender washer contains Inconel 625.

[0064] Figure 7B A top view of a fender washer according to an implementation of the present disclosure is shown.

[0065] Figure 7C A side view of a fender washer according to an implementation of the present disclosure is shown.

[0066] Fig. 8A A cross-sectional perspective view of a hub body 102 is shown in accordance with an implementation of the present disclosure. Shown in cross section are spindle fastener assemblies 800a and 800b that are configured to fasten the hub body 102 to an underlying spindle assembly that is operable to raise / lower and rotate the spindle assembly 100. In various implementations, there may be two or more spindle fastener assemblies. In the implementation shown, there are a total of four spindle fastener assemblies.

[0067] Figure 8B An enlarged perspective view of the components of a spindle fastener assembly 800a according to an implementation of the present disclosure is shown. As shown, the spindle fastener assembly 800a includes a screw 802, a flat washer 804, a Belleville washer 806, a Belleville washer 808, and a flat washer 810. Each of these components can be constructed of Inconel (e.g., Inconel 625). The configuration of the spindle fastener assembly provided increases compliance to allow relative motion due to different CTEs.

[0068] Fig. 9A A top view of a hub body 102 according to an implementation of the present disclosure is shown. In the illustrated implementation, several through holes 900a, 900b, 900c, and 900d are shown through which the spindle fastener assemblies are inserted, respectively. For example, spindle fastener assemblies 800a and 800b may be inserted and extended through through holes 900a and 900b, respectively.

[0069] Fig. 9BAn enlarged top view of a through hole 900a according to an implementation of the present disclosure is shown. The through hole 900a includes a spindle clearance hole 902a (through which the threaded portion of the screw 802 passes). The spindle clearance hole 902a is configured as a slot extending in a radial direction relative to the center of the hub body 102. In other words, the spindle clearance hole 902a does not have a perfectly circular cross-sectional shape, but extends radially away from (or toward) the center of the hub body 102, having an elliptical or slot-shaped cross-sectional shape. Each of the other through holes is similarly configured with a spindle clearance hole configured as a slot. This configuration of the spindle clearance hole as a slot addresses radial movement due to CTE differences.

[0070] Fig. 9C A bottom view of the hub body 102 is shown in accordance with an implementation of the present disclosure. Visible in the illustrated implementation are through holes 900a, 900b, 900c, and 900d as seen from the underside of the hub body 102.

[0071] Fig.9D An enlarged bottom view of the central portion of the hub body 102 including the through hole is shown, and the radial slot shape of the spindle clearance hole is shown. Material has been removed from the area around the spindle screw (e.g., screw 802). For example, in the area shown by reference numeral 910, material has been removed along the inner portion of the spindle clearance hole 902a. The remaining spindle clearance holes also show a similar configuration.

[0072] This removal of material prevents the hub from deforming and subsequently swaging onto the spindle.

[0073] Fig.10A cross-sectional view of a substrate processing system 1100' engaging multiple stations according to an implementation of the present disclosure is shown. The processing chamber 1102' includes a lower chamber portion 1102b' accommodating multiple stations and an upper chamber portion 1102a' accommodating multiple showerheads 1150. The number of showerheads 1150 in the upper chamber portion 1102a' is equal to the number of stations disposed in the lower chamber portion 1102b'. The upper chamber portion 1102a' is configured to lower the showerheads 1150 so that the showerheads 1150 are substantially aligned above the base 1140 of each station. The lower chamber portion 1102b' is configured to be supported by a support structure 1103. The support structure 1103 can be defined by any suitable structure capable of supporting a multi-station processing chamber 1102' and facilities for providing gases, RF power, pressure control, temperature control, timing, and associated controllers and electronic equipment. In one embodiment, the support structure 1103 is defined by a metal tubular structure that supports the processing chamber 1102' above the surface (e.g., a clean room floor) of the processing chamber 1102' on which the substrate processing system 1100' is installed. Vacuum pumps 1160a, 1160b are provided and docked with the lower chamber portion 1102b'. The vacuum pumps 1160a, 1160b are configured to provide sufficient gas flow, remove process gases, and / or provide pressure control within the processing chamber 1102'. Typically, the process gas is allowed to flow over the edges of the substrate 1101 and the pedestal 1140 to the vacuum pumps 1160a, 1160b, thereby defining a gas flow path 1402.

[0074] Fig.11A A top view of a multi-station substrate processing system 1100' is shown, wherein four processing stations are provided in a processing chamber 1102'. The top view is of a lower chamber portion 1102b' of the processing chamber 1102' (e.g., the upper chamber portion 1102a' is removed for illustration). The four stations are accessed by a lifting mechanism engaged with an end effector 1226'. The end effector is coupled to a rotation mechanism 1220. The end effector, when engaged, is configured to move under the wafer and simultaneously lift the wafer from the station, and then rotate at least one or more of the stations before lowering the wafer to the next position so that further plasma processing, treatment, and / or film deposition can be performed on the respective wafer.

[0075] Fig. 11BA schematic diagram of an embodiment of a multi-station substrate processing system 1100' having an inbound load lock 1301 and an outbound load lock 1303 is shown. A robot 1305 is configured to load wafers from a cassette loaded by a wafer boat 1313 into the inbound load lock 1301 via an atmospheric port 1310 at atmospheric pressure. The inbound load lock 1301 is coupled to a vacuum source (not shown) so that the inbound load lock 1301 can be evacuated when the atmospheric port 1310 is closed. The inbound load lock 1301 also includes a chamber transport port 1316 that docks with the processing chamber 1102'. Therefore, when the chamber transport port 1316 is open, another robot (not shown) can move the wafer from the inbound load lock 1301 to the pedestal 1140 of the first processing station disposed in the lower chamber portion 1102b' for processing.

[0076] The depicted processing chamber 1102' includes four processing stations, Figure 2B In the illustrated embodiment they are numbered 1 through 4. In some embodiments, the processing chamber 1102' can be configured to maintain a low pressure environment so that wafers can be transferred between processing stations without experiencing vacuum break and / or air exposure. Fig. 11B Each processing station depicted in FIG. 1 includes a pedestal 1140 to receive a wafer and a process gas delivery line inlet (not shown).

[0077] exist Fig.11A and 11B In the configuration of FIG. 1 , no grounding plate is provided around each pedestal. Therefore, the lower chamber body is exposed and the RF ground return path is typically through the chamber wall. This configuration does not provide any symmetry for the RF ground return path. In an alternative embodiment, a grounding plate may be included to provide a symmetrical RF ground return path.

[0078] The lifting mechanism includes an end effector 1226' connected to a rotating mechanism 1220. In some embodiments, the rotating mechanism 1220 is a spindle operated by a spindle motor (not shown).

[0079] When the wafer must be moved, the lift pins are engaged using the lift pin control. The lift pins lift the wafer from the pedestal 1140. The end effector (also known as a wafer blade or wafer paddle) moves under the wafer and disengages the wafer from the lift pins. The lift pins retract into the housing, and the spindle and end effector rotate the wafer to the next pedestal 1140. The lift pins engage again to receive the wafer from the end effector. The end effector and spindle are rotated away, and the wafer is received on the pedestal 1140. The transfer of the wafer is coordinated so that the wafer is positioned on a different pedestal to allow further processing of the wafer. In the illustrated embodiment, the lift pins are strategically disposed in the body of the pedestal so as not to obstruct the movement of the end effector when the lift pins are engaged.

[0080] Fig.12A control module 1600 for controlling the above system is shown. For example, the control module 1600 may include a processor, a memory, and one or more interfaces. The control module 1600 may be used to control the equipment in the system based in part on the sensed value. For example only, the control module 1600 may control one or more of the valve 1602, the filter heater 1604, the pump 1606, and other devices 1608 based on the sensed value and other control parameters. For example only, the control module 1600 receives the sensed value from a pressure gauge 1610, a flow meter 1612, a temperature sensor 1614, and / or other sensors 1616. The control module 1600 may also be used to control process conditions during the precursor delivery and deposition of the film. The control module 1600 will typically include one or more storage devices and one or more processors.

[0081] The control module 1600 can control the activities of the precursor delivery system and the deposition device. The control module 1600 executes a computer program, which includes grouped instructions for controlling process timing, conveying system temperature, pressure difference across filters, valve positions, mixing of gases, chamber pressure, chamber temperature, wafer temperature, radio frequency (RF) power level, wafer chuck or pedestal position, and other parameters of a specific process. The control module 1600 can also monitor the pressure difference and automatically switch the gas phase precursor delivery from one or more paths to one or more other paths. In some embodiments, other computer programs stored in a memory device associated with the control module 1600 can be used.

[0082] Typically, there will be a user interface associated with the control module 1600. The user interface may include a display 1618 (e.g., a display screen and / or graphical software display of apparatus and / or process conditions), and a user input device 1620, such as a pointing device, keyboard, touch screen, microphone, etc.

[0083] Computer programs for controlling precursor delivery, deposition and other processing in a process sequence may be written in, for example, any conventional computer readable programming language: assembly language, C, C++, Pascal, Fortran or others. Compiled object code or scripts are executed by a processor to perform the tasks identified in the program.

[0084] Control module parameters relate to process conditions such as, for example, filter pressure differential, process gas composition and flow rate, temperature, pressure, plasma conditions (eg, RF power level and low frequency RF frequency), cooling gas pressure, and chamber wall temperature.

[0085] The system software can be designed or configured in many different ways. For example, various chamber component subroutines or control objects can be written to control the operation of the chamber components necessary to perform the deposition process of the present invention. Examples of programs or program segments for this purpose include substrate positioning code, process gas control code, pressure control code, heater control code, and plasma control code.

[0086] The substrate positioning program may include program code for controlling chamber components that are used to load the substrate onto a pedestal or chuck and control the spacing between the substrate and other components of the chamber (e.g., a gas inlet and / or a target). The process gas control program may include code for controlling gas composition and flow rate and, optionally, for flowing gas into the chamber to stabilize the pressure in the chamber prior to deposition. The filter monitoring program includes code for comparing one or more measured differences with one or more predetermined values ​​and / or code for switching paths. The pressure control program may include code for controlling the pressure in the chamber by adjusting, for example, a throttle valve in the exhaust system of the chamber. The heater control program may include code for controlling the current to a heating unit that is used to heat components within a precursor delivery system, substrates, and / or other parts of the system. Alternatively, the heater control program may control the delivery of a heat transfer gas (e.g., helium) to a wafer chuck.

[0087] Examples of sensors that may be monitored during deposition include, but are not limited to, mass flow control modules, pressure sensors such as pressure gauge 1610, thermocouples (e.g., temperature sensor 1614) located within the transport system, pedestal, or chuck. Appropriately programmed feedback and control algorithms may be used with data from these sensors to maintain desired process conditions. The foregoing describes implementation of embodiments of the present invention in a single-chamber or multi-chamber semiconductor processing tool.

[0088] The preceding description of the embodiment is provided for illustration and description purposes. It is not intended to fully describe or limit the present invention. The individual elements or features of a particular embodiment are generally not limited to the particular embodiment, but even if not specifically shown or described, they are interchangeable and can be used in selected embodiments where applicable. This can also be changed in various ways. Such changes are not considered to depart from the present invention, and all such modifications are also included in the scope of the present invention.

[0089] Although the foregoing embodiments have been described in some detail for the purpose of clarity of understanding, it should be understood that certain changes and modifications may be implemented within the scope of the appended claims. Therefore, the present embodiments should be considered illustrative rather than restrictive, and these embodiments should not be limited to the details provided herein, but may be modified within the scope and equivalents of the claims.

Claims

1. A spindle assembly for transferring wafers in a multi-station processing module, include: a hub body configured to rotate about a central axis; a plurality of end effectors, each end effector having a first end configured to be coupled to the hub body and a second end configured to support a wafer; Multiple covers; and a plurality of fastener assemblies; wherein the first end of each end effector is clamped between a corresponding cover and a corresponding exterior of the hub body by a corresponding fastener assembly, the corresponding fastener assembly including a flat washer and a wave spring, the wave spring being located between the hub body and the flat washer and providing a consistent clamping force; and The corresponding fastener assembly includes the following components arranged in the following order: a barrel nut, the wave spring, the flat washer, a Belleville washer and a screw.

2. The spindle assembly according to claim 1, in, The barrel nut extends through the corresponding cover and the corresponding outer barrel nut of the hub body, and wherein the screw is connected to the barrel nut.

3. The spindle assembly according to claim 1, in, The wave spring surrounds the barrel nut.

4. The spindle assembly according to claim 1, in, The wave spring decouples the torque applied to the screw from the clamping force applied by the corresponding fastener assembly to the corresponding cover and the corresponding exterior of the hub body.

5. The spindle assembly according to claim 1, in, The lip of the respective cover is configured to fit into an undercut portion of the hub body.

6. The spindle assembly according to claim 1, in, The plurality of fastener components comprise Inconel material.

7. The spindle assembly according to claim 1, in, The hub body includes a plurality of slotted holes that facilitate coupling the hub body to a rotating spindle shaft assembly.

8. A spindle assembly for transferring wafers in a multi-station processing module, include: a hub body configured to rotate about a central axis; a plurality of end effectors, each end effector having a first end configured to be coupled to the hub body, the hub body having a recessed portion configured to receive the first end of the end effector, each end effector having a second end configured to support a wafer during transfer in the multi-station processing module; and a plurality of covers, each cover disposed on one of the first ends of the end effectors, each cover being fastened to the hub body by at least two fastener assemblies such that the first end of each end effector is sandwiched between one of the covers and the hub body; wherein each fastener assembly includes a flat washer and a wave spring, the wave spring being positioned between the hub body and the flat washer and providing a substantially uniform clamping force; and Each fastener assembly includes the following components arranged in the following order: a barrel nut, the wave spring, the flat washer, a Belleville washer and a screw.

9. The spindle assembly according to claim 8, in, The barrel nut extends through one of the caps and the hub body, and wherein the screw is connected to the barrel nut.

10. The spindle assembly according to claim 8, in, The wave spring surrounds the barrel nut.

11. The spindle assembly according to claim 8, in, The wave spring decouples the torque applied to the screw from the clamping force applied to the one of the covers and the hub body by the corresponding fastener assembly.

12. The spindle assembly according to claim 8, in, Each cover includes a lip configured to fit into an undercut portion of the hub body.

13. The spindle assembly according to claim 8, in, The fastener assembly includes Inconel material.

14. The spindle assembly according to claim 8, in, The hub body includes a plurality of slotted holes that facilitate coupling the hub body to a rotating spindle shaft assembly.

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