Electrostatic chuck filter box and mounting frame

Abstract

An apparatus and method for electrically coupling an electrostatic chuck RF filter box to a pedestal elevator. The RF filter box has a contact block and at least one alignment feature located on an outer mating surface of the RF filter box. The contact block includes a self-aligning electrical connector, and the alignment feature is configured to align the self-aligning electrical connector with a corresponding electrical connector on a frame of the pedestal elevator so that when the contact block is mounted to the frame of the pedestal elevator, the self-aligning electrical connector automatically mates with the corresponding electrical connector on the frame of the pedestal elevator.

Description

[0001] CROSS-REFERENCE TO RELATED APPLICATIONS

[0002] This application claims the benefit of priority to U.S. Application No. 15 / 982,972, filed May 17, 2018, which is incorporated herein by reference for all purposes. Technical Field

[0003] The present disclosure relates to methods and apparatus for semiconductor processing. More particularly, the present disclosure relates to electrostatic chuck filter boxes and mountings for filtering RF signals from other signals. Background Art

[0004] Semiconductor processing systems for processing substrates such as semiconductor wafers generally include a substrate support, such as a chuck, for holding the wafer during semiconductor processing. One type of chuck is an electrostatic chuck (ESC), which includes a platen having electrodes that are biased with a voltage to generate an electrostatic force between the wafer and the platen in order to hold the wafer to the platen. Generally, a DC signal is used to control a voltage supply that is used to control the clamping and unclamping functions of the ESC.

[0005] A radio frequency (RF) filter box is an electromechanical component that filters RF signals from other signals, such as sensitive DC signals (from the ESC clamping voltage) and AC signals (from the ESC heater). Generally, the RF filter box is electrically coupled to the ESC base lifter, and manual connectors are used to make each electrical connection individually. The RF filter box must first be mounted to the base lifter. Then, the panel on the RF filter box can be removed to gain access to these manual electrical connections. Making these electrical connections manually requires the manipulation of connecting wires and can be difficult and may not always be consistent. Consistent configuration of the wires is critical to the performance of the filtering circuit. Therefore, there is a need for an ESC RF filter box that provides a reliable and consistent way to make automatic electrical and mechanical connections. Summary of the invention

[0006] According to one embodiment, an electrostatic chuck RF filter box is provided, which is mounted on a frame of a pedestal elevator to produce a plurality of electrical connections. The RF filter box includes: at least one contact block and at least one alignment feature. The contact block includes a plurality of self-aligning electrical connectors located on a mating surface of the RF filter box. The mating surface is an outer surface of the RF filter box. The alignment feature is located on the mating surface of the RF filter box and is configured to align the self-aligning electrical connectors with corresponding electrical connectors on the frame of the pedestal elevator so that when the contact block is mounted on the frame of the pedestal elevator, the self-aligning electrical connectors automatically mate with the corresponding electrical connectors on the frame of the pedestal elevator.

[0007] According to another embodiment, a method for electrically coupling an electrostatic chuck RF filter box to a pedestal lifter is provided. An electrostatic chuck RF filter box is provided. The filter box includes at least one contact block and at least one alignment feature. The contact block includes a plurality of self-aligning electrical connectors located on an outer mating surface of the RF filter box, and the alignment feature is located on the outer mating surface of the RF filter box. The alignment feature is configured to align the self-aligning electrical connector with a corresponding electrical connector on the frame of the pedestal lifter so that when the contact block is mounted to the frame of the pedestal lifter, the self-aligning electrical connector automatically mates with the corresponding electrical connector on the frame of the pedestal lifter. The corresponding alignment feature on the mounting frame of the pedestal lifter is then engaged using the at least one alignment feature to position the outer mating surface of the RF filter box against the mating surface of the mounting frame of the pedestal lifter. The RF filter box is then fixed to the mounting frame of the base lifter so that the RF filter box is electrically coupled to the base lifter, wherein when the RF filter box is mounted on the base lifter, the multiple electrical connectors on the RF filter box automatically mate with the corresponding electrical connectors on the frame of the base lifter. BRIEF DESCRIPTION OF THE DRAWINGS

[0008] The present disclosure is illustrated by way of example and not by way of limitation in the figures of the accompanying drawings in which like reference numerals refer to similar components and in which:

[0009] Figure 1 is a perspective view of the front side of an RF filter box according to an embodiment.

[0010] Figure 2 yes Figure 1 An exploded view of the RF filter box is shown.

[0011] Figure 3 yes Figure 1 and 2 A perspective view of the rear side of the RF filter box is shown.

[0012] Figure 4 yes Figure 1-3 A perspective view of the underside of the RF filter box is shown.

[0013] Figure 5A is a detailed view of an embodiment of a contact block and electrical socket located in a mounting frame of an RF filter box.

[0014] Figure 5B yes Figure 5A A detailed view of one of the electrical sockets and corresponding pins shown in FIG.

[0015] Figure 6 is a perspective view of the mating side of a mounting bracket on a pedestal riser according to one embodiment.

[0016] Fig. 7A is a detailed exploded view of a contact block with electrical sockets and pins for RF signals according to one embodiment.

[0017] Figure 7B yes Fig. 7A A detailed perspective view of the contact block and electrical sockets and pins for RF signals is shown.

[0018] Fig. 8A is a detailed exploded view of a contact block and electrical socket and pins for AC signals according to one embodiment.

[0019] Figure 8B yes Fig. 8A A detailed perspective view of the contact block and electrical sockets and pins for AC signals is shown.

[0020] Fig. 9 is a flow chart of a method for electrically coupling an electrostatic chuck RF filter box with a pedestal lifter according to one implementation. DETAILED DESCRIPTION

[0021] The present invention will now be described in detail with reference to several preferred embodiments thereof as shown in the accompanying drawings. In the following description, many specific details are set forth in order to provide a thorough understanding of the present invention. However, it will be apparent to those skilled in the art that the present invention may be implemented without some or all of these specific details. In other cases, known processing steps and / or structures are not described in detail in order to obscure the present invention.

[0022] refer to Figure 1-9, illustrating an embodiment of the RF filter box 100. The RF filter box 100 is an electromechanical assembly that is mounted on a rack of a base lifter 610 of an ESC to create an electrical connection. According to some embodiments, the base lifter 610 can be moved. The RF filter box 100 filters RF signals from other signals, such as sensitive DC signals (from the ESC clamp) and AC signals (from the heater of the ESC). As described in more detail herein, according to one embodiment, the mechanical portion of the RF filter box 100 uses sockets that are assembled into custom contact blocks. These sockets are then matched with pins provided on a mounting rack of the base lifter assembly to create automatic electrical connections for RF, AC, and DC signals. As discussed in more detail below, alignment pins on the RF filter box 100 can be used to help form the match and make the match reliable. Accurate and repeatable electrical connection configurations ensure the integrity and reliability of RF, AC, and DC signals.

[0023] Figure 1-4 An embodiment of an RF filter box 100 is shown, which is configured to be mounted to an ESC base riser mounting bracket ( Figure 6 ).like Figure 1-4 As shown, the RF filter box 100 has a housing 110 in which wires and other components are stored. Figure 1-2 As shown, on the front side, the housing 110 is closed with a housing cover 120. Figure 3 As shown, the filter box mounting bracket 112 is located at the rear side of the RF filter box 100. The mounting bracket 112 enables the RF filter box 100 to be mounted on the mounting bracket 600 of the base lifter 610 ( Figure 6 ). The outer surface of the RF filter box 100 includes a housing 110, a housing cover 120, and a mounting bracket 112. In the embodiment, the RF filter box 100 also includes a plurality of fan assemblies, which include an ESC / high frequency (HF) filter fan assembly 130, a low frequency (LF) filter fan assembly 140, and a fan sensing assembly 150.

[0024] like Figure 1-4 As shown, an AC connector 160 is provided on the RF filter box to receive the AC signal from the heater circuit. Figure 2 is an exploded view of the RF filter box 100 and shows the components within the RF filter box 100 , which includes an ESC DC printed circuit board assembly (PCBA) 162 , a low frequency RF PCBA 164 for low frequency input, and a high frequency RF PCBA 166 for high frequency input. Figure 4 A bottom view of the RF filter box 100 is shown with an AC connector 160 , an RF connector 168 , and a DC connector 169 .

[0025] In order to electrically connect the RF filter box 100 to the base lifter 610, the mounting bracket 112 located on the rear side (mating surface) of the RF filter box 100 is arranged to mate with the mounting bracket 600 ( Figure 6 ) and install it thereon. Figure 3 As shown, features to aid alignment are provided on the mating surface of the mounting bracket 112. These alignment features include a self-aligning AC connector 170 for the AC heater circuit, a self-aligning RF connector 172 for the RF input, mounting keyway holes 174, mounting alignment pins 176, and bracket mounting holes 178.

[0026] In the embodiment, the keyway plug 604 is configured to be inserted into and snapped into the keyway hole 174 on the mounting bracket 112 of the RF filter box 100. Figure 3 As shown, holes 606 are also provided on the mating surface of the RF filter box 100 to receive corresponding alignment pins 176 on the mounting bracket 112 of the RF filter box 100. In other embodiments, the mating surface of the mounting bracket 112 may have only one alignment feature, which may be one of an alignment pin, a hole, a keyway plug, and a keyway hole. It should be understood that any suitable alignment feature can be used to align the two mounting brackets 112, 600. According to other embodiments, the mating surface of the mounting bracket 112 may have any number of such alignment features. The alignment features can be provided in any combination, and generally speaking, the pins or protrusions on one mating surface (mounting bracket 112) are arranged to cooperate with corresponding grooves or holes on another mating surface (mounting bracket 600). These alignment features can be any shape from a simple circular or cylindrical shape to a more complex shape, such as a keyway hole or the like.

[0027] It should be understood that this alignment feature is configured to help align the self-aligning electrical connector 171 on the mounting frame 112 with the corresponding electrical connector 601 on the mounting frame 600 of the base lifter 610, so that when the mounting frames 112, 600 are aligned and their mating surfaces are pushed together, the self-aligning electrical connector 171 automatically mates with the corresponding electrical connector 601 on the mounting frame 600 of the base lifter 610. These alignment features automatically and repeatably produce electrical and mechanical connections between the RF filter box 100 and the ESC base lifter 610 as much as possible. These alignment features enable electrical coupling without the need for manual operation of connecting wires. For the performance of the filter circuit, the consistent configuration of the connecting wires is key.

[0028] The keyway holes 174 are configured to receive and snap into place with corresponding keyway inserts 604 on the pedestal lifter mount 600. Likewise, the pins 176 on the mount 112 of the RF filter box 100 are configured to be inserted into corresponding holes 606 in the mount 600 of the pedestal lifter 610. In addition to these alignment features, the mount 112 is also provided with self-aligning AC connectors 170 and self-aligning RF connectors 172.

[0029] Each of the self-aligning AC connector 170 and the self-aligning RF connector 172 includes a contact block 173 having an electrical connector 171 mounted therein. In the described embodiment, the electrical connector 171 is a socket mounted within the contact block 173 and allows automatic electrical connection to a pin 601 on the pedestal elevator mount 600 when the RF filter box 100 is mounted to the movable pedestal elevator assembly. It should be understood that in other embodiments, the electrical connector 171 on the mount may be a pin and the electrical connector 601 on the pedestal elevator mount 600 may be an electrical socket.

[0030] Each electrical socket 171 is configured to receive a corresponding pin 601 on the pedestal riser mount 600 to create an electrical connection between the RF filter box 100 and the ESC pedestal riser 610. Suitable push-pull socket-pin connectors are commercially available from ODU USA, Inc. (Camarillo, California). Figure 5A and 5B A detailed view of this push-pull socket pin connector. Figure 5A A plurality of electrical sockets 171 are shown assembled within a contact block 173. Figure 5B As shown, the socket 171 has a spring wire 175 that acts as a lining for the inner surface of the socket 171 that contacts the pin 601 when the pin 601 is inserted into the socket 171.

[0031] The contact block 173 on the mounting frame 112 is formed of an insulating material. According to one embodiment, the contact block 173 is formed of Ultem1000 (UL94 V0), which is an amorphous thermoplastic polyetherimide (PEI) resin manufactured by SABIC (Saudi Basic Industries Corporation). Ultem1000 has high dielectric strength and thermal impedance. It should be understood that the insulating contact block 173 has electrical characteristics of voltage isolation, and the contact block 173 can be designed to allow close pins to align with the pins and provide separation for electrical isolation at the same time.

[0032] In the described embodiment, the self-aligning AC connector 170 and the self-aligning RF connector 172 allow for automatic electrical connection of 3 RF signals and 4 AC signals between the RF filter box 100 and the pedestal lifter assembly. It should be understood that in other embodiments, there may be a different number of RF and AC signals.

[0033] like Figure 6 As shown, the mounting bracket 600 on the base lifter 610 is configured to mate with the mounting bracket 112 (mating surface) of the RF filter box 100. The mounting bracket 112 of the RF filter box 100 can be fixed to the mounting bracket 600 on the base lifter 610 using screws (not shown), which pass through the bracket mounting holes 178 of the mounting bracket 112 of the RF filter box 100 and the corresponding bracket mounting holes 608 of the base lifter mounting bracket 600.

[0034] In the described embodiment, the contact blocks 673 and electrical pins 601 on the pedestal elevator mounting frame 600 are positioned to mate with corresponding contact blocks 173 and receptacles 171 on the mounting frame 112 of the RF filter box 100 when the two mounting frames 112, 600 are aligned. As discussed above, alignment features on the mounting frames assist in alignment, and the electrical receptacles 171 are configured to automatically electrically couple with corresponding pins 601 when the mounting frames 112, 600 are pushed together after alignment.

[0035] In this embodiment, the mounting frame 600 is also provided with a snap-in dielectric mounting plate 602, which is used to isolate the electrical connector from the ground plane and the metal wall. Figure 6 As shown, the contact block 673 is mounted in the mounting plate 602. According to one embodiment, the mounting plate 602 is formed of Ultem, and nylon fasteners secure the mounting plate 602 to the mounting frame 600.

[0036] Fig. 7A and 7B is a detailed view of one embodiment of a contact block with electrical sockets and pins for RF signals, and Fig. 8A and 8B is a detailed view of one embodiment of a contact block and electrical socket and pins for AC signals. Figure 7B and 8B Shows the contact block and electrical connector in mated position. Figures 7A-8B As shown, in this embodiment, the electrical socket 171 is mounted in the contact block 173.

[0037] Likewise, the pin 601 is mounted in the contact block 673. In the present embodiment, the contact block 673 comprises two parts 673A, 673B to allow the pin 601 to be replaced even after installation. That is, the rear portion of the contact block 673 is mounted on the mounting block 600 of the base lifter 610, and the pin 601 is inserted into the rear portion 673B. Then, after the pin 601 is properly positioned, the front portion 673A is attached to the rear portion 673B. Therefore, if the pin 601 needs to be replaced, the front portion 673A can be removed without removing the entire assembly from the base lifter mounting block 600.

[0038] The contact block 173, 673 is fastened to the mounting frame 112, 600 by a fastener formed of an insulating material such as nylon. Figures 7A-8B As shown, the contact block 173, 673 is snapped onto the mounting block 112, 600 by a plurality of fasteners including a nylon bracket 177A, a nylon washer 177B, and a nylon cap screw 177C. It should be understood that the self-alignment of the contact block 173, 673 allows some float to produce a difference in position on the mating side. The slightly larger hole and bracket 177A allow the contact block 173, 673 to float.

[0039] Fig. 9 is a flow chart of a method 900 for electrically coupling an electrostatic chuck RF filter box to a pedestal elevator. In step 910, an ESC RF filter box is provided. The RF filter box includes at least one contact block and at least one alignment feature on an outer mating surface of the RF filter box. The contact block includes a plurality of self-aligning electrical connectors on the outer mating surface of the RF filter box, and the at least one alignment feature is configured to align the self-aligning electrical connectors with corresponding electrical connectors on a frame of the pedestal elevator to automatically mate the self-aligning electrical connectors with corresponding electrical connectors on the frame of the pedestal elevator when the contact block is mounted to the frame of the pedestal elevator. In step 920, the outer mating surface of the RF filter box is positioned against the mating surface of the mounting frame of the pedestal elevator by engaging a corresponding alignment feature on the mounting frame of the pedestal elevator using the at least one alignment feature. In step 930, the RF filter box is fixed to the mounting frame of the base elevator to electrically couple the RF filter box with the base elevator, wherein when the RF filter box is fixed to the mounting frame of the base elevator, multiple electrical connectors on the RF filter box automatically mate with corresponding electrical connectors on the frame of the base elevator.

Claims

1. An electrostatic chuck RF filter box mounted on a frame of a pedestal lifter to create a plurality of electrical connections, the RF filter box comprising: at least one contact block comprising a plurality of self-aligning electrical connectors located on a mating surface of the RF filter box, wherein the mating surface is an exterior surface of the RF filter box; and and at least one alignment feature located on the mating surface of the RF filter box, wherein the at least one alignment feature is configured to align the self-aligning electrical connector with a corresponding electrical connector on the frame of the base lifter so that when the contact block is mounted to the frame of the base lifter, the self-aligning electrical connector automatically mates with the corresponding electrical connector on the frame of the base lifter.

2. The electrostatic chuck RF filter box of claim 1, comprising at least two contact blocks, wherein a first contact block is configured to filter RF signals and a second contact block is configured to filter AC signals.

3. The electrostatic chuck RF filter box of claim 2, wherein the first contact block is configured to filter at least three RF signals and the second contact block is configured to filter at least four AC signals.

4. The electrostatic chuck RF filter box of claim 1 , wherein the RF filter box filters low frequency and high frequency RF signals.

5. The electrostatic chuck RF filter box of claim 1, wherein the RF filter box filters an AC heater signal.

6. The electrostatic chuck RF filter box of claim 1, wherein the RF filter box filters a DC clamping voltage.

7. The electrostatic chuck RF filter box of claim 1 further comprising at least one fan assembly.

8. The electrostatic chuck RF filter box of claim 1, comprising at least two alignment features located on the mating surface.

9. The electrostatic chuck RF filter box of claim 8, wherein the at least two alignment features comprise an alignment pin and a keyway hole.

10. The electrostatic chuck RF filter box of claim 8, wherein the at least two alignment features comprise at least two alignment pins.

11. The electrostatic chuck RF filter box of claim 8, wherein the at least two alignment features comprise at least two keyway holes.

12. The electrostatic chuck RF filter box of claim 1, wherein the susceptor lifter is movable.

13. The electrostatic chuck RF filter box of claim 1, wherein the at least one contact block is formed of an insulating material.

14. The electrostatic chuck RF filter box of claim 1, wherein the at least one contact block is fastened to the housing of the RF filter box by a fastener formed of an insulating material.

15. A method for electrically coupling an electrostatic chuck RF filter box to a pedestal lifter, the method comprising: The electrostatic chuck RF filter box is provided, wherein the RF filter box comprises: at least one contact block comprising a plurality of self-aligning electrical connectors located on an outer mating surface of the RF filter box; and at least one alignment feature located on the outer mating surface of the RF filter box, wherein the at least one alignment feature is configured to align the self-aligning electrical connector with a corresponding electrical connector on a shelf of the pedestal elevator so that the self-aligning electrical connector automatically mates with the corresponding electrical connector on the shelf of the pedestal elevator when the contact block is mounted to the shelf of the pedestal elevator; positioning the outer mating surface of the RF filter box against the mating surface of the mounting frame of the pedestal elevator by engaging a corresponding alignment feature on the mounting frame of the pedestal elevator using the at least one alignment feature; as well as The RF filter box is fixed to the mounting frame of the base lifter to electrically couple the RF filter box with the base lifter, wherein when the RF filter box is fixed to the mounting frame of the base lifter, the multiple electrical connectors on the RF filter box automatically mate with the corresponding electrical connectors on the frame of the base lifter.

16. The method of claim 15, wherein the RF filter box comprises at least two contact blocks, wherein a first contact block is configured to filter RF signals and a second contact block is configured to filter AC signals.

17. The method of claim 16, wherein the first contact block is configured to filter at least three RF signals and the second contact block is configured to filter at least four AC signals.

18. The method of claim 15, wherein the RF filter box filters low frequency and high frequency RF signals.

19. The method of claim 15, wherein the RF filter box filters an AC heater signal.

20. The method of claim 15, wherein the RF filter box filters a DC clamping voltage.

21. The method of claim 15, wherein the RF filter box comprises at least two alignment features located on the mating surface.

22. The method according to claim 21, further comprising: aligning alignment pins on the mating surface with keyway holes on the frame of the base lifter; as well as Align the keyway holes on the mating surface with the alignment pins on the frame of the pedestal lifter.

23. The method of claim 21 further comprising aligning at least two alignment pins with two corresponding keyway holes on the frame of the pedestal lifter.

24. The method of claim 21 further comprising aligning at least two keyway holes with two corresponding alignment pins on the frame of the pedestal lifter.

25. The method of claim 15, wherein the susceptor elevator is movable.

26. The method of claim 15, wherein the at least one contact block is formed of an insulating material.

27. The method of claim 15, wherein the at least one contact block is fastened to the housing of the RF filter box by a fastener formed of an insulating material.

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