Bidirectional indexing device

Abstract

In an exemplary embodiment, a bidirectional indexing device includes a plurality of bidirectional indexing heads, which can be operated independently of each other or in cooperation to adjust the gap between the substrate and the susceptor in the substrate processing chamber. In some embodiments, a bidirectional indexing head includes: a base; a rotatable plate rotatable relative to the base, the rotatable plate including a plurality of profiled recesses, each of which defines a cam surface therein; and a plurality of cam pins, each of which is configured to act on the cam surface of the corresponding profiled recess when actuated to move the rotatable plate in a first or second rotatable direction.

Description

[0001] Priority claim

[0002] This application claims priority to U.S. Patent Application No. 62 / 864,994, filed on June 21, 2019 by Vintila et al., entitled “Bidirectional Indexing Apparatus,” the entire disclosure of which is incorporated herein by reference. Technical Field

[0003] The present disclosure generally relates to a bidirectional indexing device for a substrate processing chamber. In an exemplary embodiment, the bidirectional indexing device includes a plurality of bidirectional indexing heads that can operate independently of each other or in conjunction with each other to adjust the gap between a substrate and a susceptor in a substrate processing chamber. Background Art

[0004] During some substrate processing operations, the substrate is supported on a susceptor within a processing chamber. Typically, the height or gap between the substrate and the susceptor is not adjustable. However, in modern semiconductor processes, the inability to make gap adjustments can be a significant drawback, especially when seeking to optimize chamber conditions to create nano-sized structures in a plasma enhanced chemical vapor deposition (PECVD) process, for example.

[0005] The background description provided here is for the purpose of generally presenting the context of the present disclosure. The work of the presently designated inventors is neither explicitly nor implicitly admitted to be prior art against the present disclosure to the extent that it is described in this background section and in aspects of the specification that were not determined to be prior art at the time the application was filed. Summary of the invention

[0006] The present disclosure generally relates to a bidirectional indexing device for a susceptor in a substrate processing chamber. In some examples, the indexing device includes a plurality of bidirectional indexing heads that operate individually or in conjunction to adjust the height of a spacing gap between the susceptor and a substrate supported by the susceptor.

[0007] In some examples, the bidirectional indexing device includes a rotatable plate having an axis of rotation, and a plurality of profiled pockets formed in the plate. In some examples, the profiled pockets are arranged to be equally spaced around the circumference of the plate. In some examples, in use positioning, a recess is provided or formed in the underside of the plate. Each profiled recess may include a profiled surface used as a cam surface or cam. The cam may have a symmetry plane in the middle of the recess.

[0008] In some examples, the indexing device can include three cam pins (or followers) that can be urged in an axial direction orthogonal to the plate to act on a cam to index the plate about the axis of rotation (e.g., in a manner that increases with rotation in both directions (forward or reverse)). In some examples, the three cam pins can act sequentially, one after the other or in an ordered pattern, to impart a series of continuous or discontinuous indexing motions to the plate in a forward or rearward direction. The sequence or pattern of cam pin actuation can produce plate rotation in one direction or the other, or a combination thereof.

[0009] In some examples, the axis of rotation of the plate provides or is aligned with the lifting direction of the indexing device. The rotating plate of each indexing head in the indexing device can act on a threaded screw or other device to transfer motion to a substrate supported on a base. The motion may include lowering, raising, tilting, or other motion of the substrate relative to the base, as described more fully below. The sequence or pattern of cam pin actuation of multiple indexing heads can impart different orientations of the plate (e.g., horizontal or inclined orientations during substrate processing) or vertical adjustment of the height of the spacing gap between the base and the substrate supported by the base. In some examples, the cam pin is actuated by a fluid pressure difference (e.g., actuated by one or more hydraulic linear pistons controlled by a controller).

[0010] In some examples, a bi-directional indexing head includes: a base; a rotatable plate rotatable relative to the base, the rotatable plate including a plurality of shaped recesses, each of the shaped recesses defining a cam surface therein; and a plurality of cam pins, each cam pin being configured to act on the cam surface of a corresponding shaped recess when actuated to move the rotatable plate in a first or second rotatable direction.

[0011] In some examples, the respective positions of the plurality of shaped recesses and the cam pin are related to enable continuously increasing indexing.

[0012] In some examples, each shaped recess defines a cam surface having a plane of symmetry; and each of the plurality of cam pins is arranged to act on a corresponding cam surface of the shaped recess in a sequential manner.

[0013] In some examples, the plane of symmetry of each shaped recess is configured to impart bi-directional rotational motion to the rotatable plate when a corresponding cam pin acts on a corresponding cam surface.

[0014] In some examples, the bi-directional indexing head further includes a threaded shaft connected to the rotatable plate.

[0015] In some examples, the bi-directional indexing device includes at least one indexing head as generally described above or as described herein.

[0016] In some examples of bi-directional indexing heads and bi-directional indexing devices, a portion of the cam surface of the profiled recess is linear in profile. In some examples of bi-directional indexing heads and bi-directional indexing devices, a portion of the cam surface of the cam pin is arcuate in profile. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Some embodiments are shown by way of example and not limitation in the figures of the accompanying drawings:

[0018] Figure 1 is a schematic diagram of a processing chamber according to some examples in which some examples of the method of the present disclosure can be employed.

[0019] Figure 2 is a schematic diagram of an indexing device according to an exemplary embodiment.

[0020] Figure 3 According to an exemplary embodiment, Figure 4 Schematic cross-sectional view of a portion of the indexing head taken along line AA.

[0021] Figure 4 is a schematic cross-sectional view of an underside of an index head according to an exemplary embodiment.

[0022] Figure 5 Aspects of the actuation states of the indexing head are shown according to exemplary embodiments.

[0023] Figure 6-7 Aspects of bi-directional movement of the indexing head are shown according to exemplary embodiments.

[0024] Figure 8 is a block diagram illustrating an example of a machine upon which one or more exemplary embodiments may be implemented or by which one or more exemplary embodiments may be controlled. DETAILED DESCRIPTION

[0025] The following description contains systems, methods, techniques, instruction sequences, and computing machine program products that implement the illustrative embodiments of the present disclosure. In the following description, for the purpose of illustration, many specific details are described to provide a complete understanding of the exemplary embodiments. However, it will be apparent to those skilled in the art that the present disclosure can be practiced without these specific details.

[0026] Portions of the disclosure of this patent document contain material that is subject to copyright protection. The copyright owner has no objection to the facsimile reproduction by anyone of the patent document or the patent disclosure, as it appears in the Patent and Trademark Office patent files or records, but otherwise reserves all copyright rights whatsoever. The following statement applies to any data described below and in the accompanying drawings that constitute a part of this document: Copyright Lam Research Corporation, 2019-2020, All Rights Reserved.

[0027] Reference now Figure 1 , an exemplary arrangement 100 of a plasma-based processing chamber is shown. The present subject matter can be used in various semiconductor manufacturing and substrate processing operations, but in the illustrated example, a plasma-based processing chamber is described in the context of a plasma-enhanced or free radical-enhanced chemical vapor deposition (CVD) or atomic layer deposition (ALD) operation. Those skilled in the art will also recognize that other types of ALD processing techniques are known (e.g., thermal-based ALD operations) and can be combined with non-plasma-based processing chambers. An ALD tool is a special type of CVD processing system in which an ALD reaction occurs between two or more chemical substances. The two or more chemical substances are referred to as precursor gases and are used to form a thin film deposition of material on a substrate (e.g., a silicon substrate used in the semiconductor industry). The precursor gases are sequentially introduced into the atomic layer deposition processing chamber and react with the substrate surface to form a deposited layer. Typically, the substrate repeatedly interacts with the precursor to slowly deposit one or more material film layers of increasing thickness on the substrate. In certain applications, a variety of precursor gases can be used to form one or more thin films of various types in a substrate manufacturing process.

[0028] Figure 1 A plasma-based processing chamber 101 is shown in which a showerhead 103 (which may be a showerhead electrode) and a substrate support assembly or pedestal 107 are arranged. The substrate support assembly or pedestal 107 may include an indexing head, such as described in more detail below. Generally, the substrate support assembly 107 seeks to provide a substantially isothermal surface and may serve as a heating element and heat sink for the substrate 105. The substrate support assembly 107 may include an electrostatic chuck (ESC) including a heating element to assist in processing the substrate 105 as described above. The substrate 105 may include a substrate comprising an elemental semiconductor (e.g., silicon or germanium), a substrate comprising a composite element (e.g., gallium arsenide (GaAs) or gallium nitride (GaN)), or a variety of other substrate types (including conductive, semiconductive, and non-conductive substrates).

[0029] In operation, a substrate 105 is loaded onto the substrate support assembly 107 through the loading port 109. A gas line 113 can supply one or more process gases (e.g., precursor gases) to the showerhead 103. The showerhead 103, in turn, delivers the one or more process gases into the plasma-based processing chamber 101. A gas source 111 (e.g., one or more precursor gas ampoules) that supplies the one or more process gases is coupled to the gas line 113. In some examples, an RF (radio frequency) power source 115 is coupled to the showerhead 103. In other examples, the power source is coupled to the substrate support assembly 107 or the ESC.

[0030] A point of use (POU) and manifold combination (not shown) controls one or more process gases into the plasma-based processing chamber 101 before entering the showerhead 103 and downstream gas lines 113. In the case of a plasma-based processing chamber 101 for depositing thin films in a plasma-enhanced ALD operation, the precursor gases may be mixed in the showerhead 103.

[0031] In operation, the plasma-based processing chamber 101 is evacuated by a vacuum pump 117. RF power is capacitively coupled between the showerhead 103 and a lower electrode (not explicitly shown) contained in or on the substrate support assembly 107. The substrate support assembly 107 is typically provided with two or more RF frequencies. For example, in various embodiments, the RF frequency can be selected from at least one of about 1 MHz, 2 MHz, 13.56 MHz, 27 MHz, 60 MHz and other desired frequencies. Coils for blocking or partially blocking specific RF frequencies can be designed as needed. Therefore, the specific frequencies discussed here are provided only for ease of understanding. RF power is used to excite one or more processing gases into a plasma in the space between the substrate 105 and the showerhead 103. Plasma can help deposit various layers (not shown) on the substrate 105. In other applications, plasma can be used to etch device features into various layers on the substrate 105. RF power is coupled at least through the substrate-support assembly 107. The substrate-support assembly 107 may have a heater ( Figure 1 Detailed design of the plasma based processing chamber 101 may vary.

[0032] Figure 2 200. The indexing device 200 includes a plurality of indexing heads (or mechanisms) generally shown at 202. The illustrated exemplary embodiment includes three indexing heads 202 provided in a circular arrangement, as shown. Each indexing head 202 is positioned proximate an edge of a substrate (e.g., substrate 204). The indexing heads 202 are arranged to engage with a base 206 (e.g., Figure 1 The indexing head 202 is associated with the base 107 of the processing chamber (e.g. Figure 1The substrate 204 is supported in a processing chamber 101 of the embodiment of the present invention. The indexing heads 202 can operate independently of each other or together (coordinated) under the guidance of a controller (not shown) to adjust the vertical height of the gap 208 between the substrate 204 and the pedestal 206. The vertical adjustment is performed along the lifting direction 210 indicated by the numbered arrows. As described in more detail below, each indexing head can include a threaded pin driven by a bidirectional indexing mechanism. In some examples, where more precise gap adjustment is required, the threaded pin includes a differential screw.

[0033] The exemplary indexing head 300 is Figure 3 The indexing head 300 includes a base 302 and a rotating plate 304. The rotating plate 304 is fixed in the vertical direction relative to the base 302 but can rotate relative to the base 302. The opposite rotational arrangement is possible. As shown, a shaped recess (or cam) 306 is formed in the lower side of the plate 304. The shaped recess 306 includes a shaped surface 308 that serves as a cam surface 308. The cam surface 308 may have a symmetry plane at the middle 310 of the shaped recess 306. In the example shown, the middle 310 of the shaped recess 306 is located at the vertex of the recess 306. Other positions within the recess are also possible. The cam surface 308 is planar or linear in the view. Other profiles are also possible. Reference Figure 4 , a series of equally spaced shaped recesses 306 , in this case eight recesses 306 , are provided in the rotatable plate 304 of the indexing head 300 .

[0034] return Figure 3 The base 302 of the indexing head 300 includes a hole 312. The cam pin 314 can be passed through the hole 312 along the Figure 2 axial movement aligned with the lifting direction 210 in the lifting direction. The cam pin 314 has a shaped head 316, which acts on the cam surface 308 of the shaped recess 306 in use. It should be understood that axial movement of the cam pin 314 (upward or downward in the view) will cause or allow bi-directional (left or right) rotational movement of the rotatable plate 304. In the illustrated view, the cam pin is shown as being in a "locked" upward position, with the head 316 of the cam pin 314 fixed in the apex of the recess 306. When the pin 314 is locked in this upward position, bi-directional rotational movement of the rotatable plate 304 is not possible. In the other unlocked position, upward axial movement of the cam pin 314 acting on the cam surface 308 imparts bi-directional rotational movement to the rotatable plate 304 to the left or right about the rotation axis 404, depending on which side of the symmetry plane the cam pin 314 acts. Referring again to Figure 4 In the example shown, three cam pins 314 are provided. Other numbers and arrangements of the cam pins 314 are also possible.

[0035] Further references Figure 4 In some examples, the rotatable plate 304 is fixed to or associated with a threaded lift pin or shaft 402 of the indexing head 300. Under the action of the cam pin 314, the threaded shaft 402 is driven by the rotatable plate 304 to rotate in a forward or reverse (bidirectional) direction. Back to Reference Figure 2 As noted therein, this rotational movement of the threaded shaft causes the index head 300 to raise or lower the substrate 204 to adjust the gap 208 between the substrate 204 and the susceptor 206 at each position of the index head (202 or 300).

[0036] Reference Figure 5 , the indexing head 202 or 300 may have an actuation pitch 502. This represents the degree of rotational motion imparted to the rotatable plate 304 for a single stroke of the cam pin 314. The upper series 500 of three views indicates three relative positions of the cam pin 314 in a ready-to-actuate state. In some examples, only one cam pin 314 is actuated at a time. The arrows in the series of views indicate the direction of rotation when the cam pin is pushed upward. Thus, in the left view, the axial upward movement of the cam pin 314 acting on the cam surface 308 of the recess 306 drives the rotatable plate 304 to the left. The middle view shows a cam pin configuration that imparts opposite directions of rotation, so that the symmetrical cams (planes of symmetry) provide bidirectional motion to the indexing head. The right view in the series 500 depicts a locked configuration of the cam pin 314 and the rotatable plate 304. The lower series 504 of three views depicts the configuration of the cam pin between actuation states. In some examples, two cam pins 314 are in this state at the same time, i.e., in, for example Figure 6-7 The end of the recess 306 is shown.

[0037] Therefore, in some examples, the indexing device 200 includes a plurality of bidirectional indexing heads 202 (or 300) that operate individually or in coordination to adjust the height of the spacing gap 208 between the susceptor 206 and the substrate 204 supported by the susceptor 206. In some examples, the bidirectional indexing device 200 includes a rotating shaft (404, Figure 4 ) and one or more profiled recesses 306 formed in the rotatable plate 304. In some examples, the profiled recesses 306 are arranged to be equally spaced around the circumference of the plate 304, such as shown in the figure. In some examples, the recesses 306 are provided or formed in the underside of the plate 304. Each profiled recess 306 may include a profiled surface that serves as a cam surface 308 or cam. The cam surface 308 may have a symmetry plane in the middle of the recess 306.

[0038] In some examples, the indexing device 200 can include one or more cam pins (or followers) 314 that can be urged in an axial direction orthogonal to the rotatable plate 304 to act on the cam surface 308 of the shaped recess 306 to index the rotatable plate 304 about the rotation axis 404 (e.g., in rotational increments in a bidirectional (forward or rearward) direction). In some examples, the rotational axis of the plate provides or is aligned with the lifting direction of the indexing device. The rotating plate of each indexing head in the indexing device can act on a threaded screw or other device to lower or raise the base, as described more fully below.

[0039] Thus, in some examples, multiple cam pins 314 may be acted upon sequentially, one after the other or in an ordered pattern, to apply a series of continuous or discontinuous indexing motions to the rotatable plate 304 in a forward or rearward direction (upward or downward, leftward or rightward, at each position of the indexing head 202 or 300). The sequence or pattern of cam pin actuation may produce a combination of rotation or motion of the plate 304 in one or another direction.

[0040] The sequence or pattern of actuation of the cam pins 314 within the plurality of index heads 202 or 300 allows for achieving a different planar orientation of the substrate 204 (e.g., a horizontal orientation or an inclined orientation of the substrate 204 relative to the plasma gases during substrate processing) at each of the three index head positions. Other embodiments of the index device 200 may not adjust the planar orientation of the substrate 204 but may adjust only the height of the spacing gap 208 between the pedestal 206 and the substrate 204 supported by the pedestal 206. In other examples, various combinations of planar orientation of the substrate 204 and height adjustment of the gap 208 are possible.

[0041] At this point, now refer to Figure 5-6 .exist Figure 6 , a counterclockwise actuation sequence 600 of the cam pin 314 is shown for rotating the rotatable plate 304 in a counterclockwise direction of view. The rotatable plate 304 is attached to the threaded shaft 402 of the indexing device 200. The threaded shaft 402 is driven by the rotatable plate 304 and engages with other components of the indexing head 202 or 300 to adjust the standoff gap or substrate plane orientation, for example, as described above.

[0042] The illustrated cam pins 314 can each be moved upward (into the page) to act on the inclined cam surface 308 of the corresponding profiled recess 306. Thus, when the cam pin 314 labeled C is pushed upward (into the page), the rotatable plate 304 is moved in the direction of the associated arrow 602. By actuating the cam pins labeled A and B in an ordered actuation sequence or pattern CAB, subsequent or sequential rotational movement can be imparted to the rotatable table 304. In the left view, cam pin B is unlocked and withdrawn from the locked position discussed above. Rotational movement of the rotatable plate 304 is allowed. It should be seen that during the CAB actuation sequence, cam pin C has been relocated from the right side of the associated recess 306 to the left side of the same recess 306. Cam pin A has moved to a new recess 306 relative to the rotatable plate 304. Figure 7 A similar arrangement is shown, but this time with a clockwise actuation sequence 700. In the example shown, the actuation sequence 700 of the cam pin 314 is ACB.

[0043] Although the exemplary indexing head has been described herein in the context of eight shaped recesses and three cam pins, it should be understood that other numbers and arrangements are possible. Three cam pins are considered convenient because one pin can be ready to move the rotatable plate to the left, another pin is ready to move the rotatable plate to the right, and the third pin is ready to adopt a locked position if necessary. If a simpler reciprocating motion or arrangement is required, two cam pins can be used. For example, additional cam pins can disperse the load across a greater number of pins, or provide greater engagement with a series of recesses. For example, the spacing between recesses can be configured to provide a finer indexing increment for each stroke of the cam pin. In some examples, the positions of the recesses and cam pins are related to allow continuous (smooth) or discontinuous (incremental) indexing. In the above-mentioned exemplary indexing head, the cam pin can "move" from recess to recess when the rotating plate is indexed. In other arrangements, such relocation may not be provided.

[0044] In some examples, for precision of motion and ease of control, the cam pin 314 is actuated by one or more hydraulic linear pistons controlled by a controller. The controller can control the bi-directional indexing head to impart a combination of substrate plane orientation and gap adjustment based on feedback from sensors in the process chamber 101, based on manual input from an operator, based on algorithmic instructions, or a combination of the above.

[0045] Figure 8is a block diagram illustrating an example of a machine or controller 800 by which one or more of the exemplary embodiments described herein may be controlled. In alternative embodiments, the controller 800 may operate as a standalone device, or may be connected (e.g., networked) to other machines. In a networked deployment, the controller 800 may operate in the capacity of a server machine, a client machine, or both in a server-client network environment. In one example, the controller 800 may be used as a peer machine in a peer-to-peer (P2P) network (or other distributed network) environment. In addition, although only a single controller 800 is shown, the term "machine" (controller) should also be construed to include any collection of machines (controllers) that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methods described herein, such as via cloud computing, software as a service (SaaS), or other computer cluster configuration. In some examples, and with reference to Figure 8 , the non-transitory machine-readable medium includes instructions 824 that, when read by the controller 800, cause the controller to control operations in a method including at least the non-limiting example operations described herein.

[0046] The examples described herein may include logic, multiple components or mechanisms, or may be operated by logic, multiple components or mechanisms. A circuit system is a collection of circuits implemented in a tangible entity including hardware (e.g., simple circuits, gates, logic, etc.). Circuit system components may be flexible over time and with basic hardware variability. A circuit system includes components that can perform specified operations individually or in combination when operating. In one example, the hardware of the circuit system can be designed in a fixed and immutable manner to perform specific operations (e.g., hard wiring). In one example, the hardware of the circuit system may include variable connection entity components (e.g., execution units, transistors, simple circuits, etc.), which include computer-readable media that are modified by physical means (e.g., magnetically, electrically, by a movable setting of a constant mass particle, etc.) to encode instructions for specific operations. When connecting entity components, the basic electrical properties of the hardware components are changed (e.g., from an insulator to a conductor, and vice versa). Instructions enable embedded hardware (e.g., an execution unit or a loading mechanism) to generate components of the circuit system in hardware via variable connections to perform parts of specific operations when operating. Thus, when the device is operating, the computer-readable medium is communicatively coupled to other components of the circuit system. In one example, any of the physical components can be used in more than one component in more than one circuit system. For example, in operation, an execution unit can be used in a first circuit of a first circuit system at one point in time, and reused by a second circuit of the first circuit system, or by a third circuit of the second circuit system at a different time.

[0047] The machine (e.g., computer system) 800 may include a hardware processor 802 (e.g., a central processing unit (CPU), a hardware processor core, or any combination thereof), a graphics processing unit (GPU) 832, a main memory 804, and a static memory 806, some or all of which may communicate with each other via an interconnect (e.g., a bus) 808. The controller 800 may also include a display device 810, an alphanumeric input device 812 (e.g., a keyboard), and a user interface (UI) navigation device 814 (e.g., a mouse). In one example, the display device 810, the alphanumeric input device 812, and the UI navigation device 814 may be a touch screen display. The controller 800 may additionally include a mass storage device (e.g., a drive unit) 816, a signal generating device 818 (e.g., a speaker), a network interface device 820, and one or more sensors 830, such as a global positioning system (GPS) sensor, a compass, an accelerometer, or another sensor. The controller 800 may include an output controller 828 (e.g., serial (e.g., Universal Serial Bus (USB)), parallel, or other wired or wireless (e.g., infrared (IR), near field communication (NFC), etc.) connection) to communicate with one or more peripheral devices (e.g., printer, card reader, etc.) or control the one or more peripheral devices.

[0048] The mass storage device 816 may include a machine-readable medium 822 on which one or more sets of data structures or instructions 824 (e.g., software) may be stored that implement or are used by any one or more of the techniques or functions described herein. The instructions 824 may also reside, as shown, completely or at least partially within the main memory 804, within the static memory 806, within the hardware processor 802, or within the GPU 832 during their execution by the controller 800. In one example, one or any combination of the hardware processor 802, the GPU 832, the main memory 804, the static memory 806, or the mass storage device 816 may constitute the machine-readable medium 822.

[0049] Although machine-readable medium 822 is shown as a single medium, the term "machine-readable medium" may include a single medium or multiple media (eg, a centralized or distributed database and / or associated caches and servers) configured to store one or more instructions 824.

[0050] The term "machine-readable medium" may include any medium capable of storing, encoding, or carrying instructions 824 for execution by the controller 800 and causing the controller 800 to perform any one or more of the techniques of the present disclosure; or any medium capable of storing, encoding, or carrying data structures used by or related to such instructions 824. Non-limiting machine-readable medium examples may include solid-state memory and optical and magnetic media. In one example, a large amount of machine-readable media includes a machine-readable medium 822 having a plurality of particles having a constant mass (e.g., rest mass). Therefore, the large amount of machine-readable media is not a transient propagating signal. Specific examples of large amounts of machine-readable media may include non-volatile memory, such as semiconductor memory devices (e.g., electronically programmable read-only memory (EPROM), electronically erasable programmable read-only memory (EEPROM), and flash memory devices; disks, such as internal hard disks and removable disks; magneto-optical disks; and CD-ROM and DVD-ROM disks. The instructions 824 may be further sent or received via the network interface device 820 using a transmission medium through a communication network 826.

[0051] Although examples have been described with reference to specific exemplary embodiments or methods, it is apparent that various modifications and changes may be made to these embodiments without departing from the broader scope of the embodiments. Therefore, the description and the drawings are to be regarded as illustrative rather than restrictive. The drawings constituting a part of this article show specific embodiments in an illustrative (but not limiting) manner in which the subject matter may be practiced. The illustrated embodiments are described in sufficient detail to enable those skilled in the art to practice the teachings disclosed herein. Other embodiments may be used and derived therefrom so that structural and logical substitutions and changes may be made without departing from the scope of the present disclosure. Therefore, this specific embodiment is not to be regarded as restrictive, and the scope of the various embodiments is limited only by the appended claims, together with the full scope of the equivalent schemes granted by these claims.

[0052] These embodiments of the subject matter of the present invention may be referred to herein individually and / or collectively by the term "invention", which is merely for convenience and is not intended to voluntarily limit the scope of the present application to any single invention or inventive concept (if more than one invention or inventive concept is in fact disclosed). Therefore, although specific embodiments are shown and described herein, it should be understood that any configuration calculated to achieve the same purpose can replace the specific embodiments shown. The present disclosure is intended to cover any and all adjustments or variations of the various embodiments. After reading the above description, the combination of the above embodiments and other embodiments not specifically described herein will be apparent to those skilled in the art.

Claims

1. A bidirectional indexing head, comprising: base; a rotatable plate rotatable relative to the base, the rotatable plate comprising a plurality of shaped recesses, each shaped recess defining a cam surface therein having a plane of symmetry; and a plurality of cam pins, each cam pin being arranged to act on the cam surface of a corresponding profiled recess when actuated to move the rotatable plate in a first or second rotatable direction; as well as A threaded shaft is connected to the rotatable plate, wherein the rotatable plate of the index head acts on the threaded shaft to impart motion to a substrate supported on a susceptor.

2. The bi-directional indexing head of claim 1, wherein the respective positions of the plurality of shaped recesses and cam pins are related to enable continuously increasing indexing.

3. The bi-directional indexing head of claim 2, wherein each of the plurality of cam pins is arranged to act on a corresponding cam surface of the profiled recess in a sequential manner.

4. A bi-directional indexing head according to claim 3, wherein the plane of symmetry of each shaped recess is configured to impart bi-directional rotational motion to the rotatable plate when a corresponding cam pin acts on a corresponding cam surface.

5. The bi-directional indexing head of claim 1, wherein a portion of the cam surface of the profiled recess is linear in profile.

6. The bi-directional indexing head of claim 1 wherein a portion of the cam surface of the cam pin is arcuate in profile.

7. A bidirectional indexing device, comprising at least one indexing head, wherein the indexing head comprises: base; a rotatable plate rotatable relative to the base, the rotatable plate comprising a plurality of shaped recesses, each shaped recess defining a cam surface therein having a plane of symmetry; a plurality of cam pins, each cam pin being arranged to act on the cam surface of a corresponding profiled recess when actuated to move the rotatable plate in a first or second rotatable direction; and A threaded shaft is connected to the rotatable plate, wherein the rotatable plate of the index head acts on the threaded shaft to impart motion to a substrate supported on a susceptor.

8. The bi-directional indexing device of claim 7, wherein the respective positions of the plurality of shaped recesses and cam pins are related to enable continuously increasing indexing.

9. The bi-directional indexing device according to claim 8, wherein each of the plurality of cam pins is arranged to act on a corresponding cam surface of the profiled recess in a sequential manner.

10. A bi-directional indexing device according to claim 9, wherein the plane of symmetry of each shaped recess is configured to impart bi-directional rotational movement to the rotatable plate when the corresponding cam pin acts on the corresponding cam surface.

11. The bi-directional indexing device of claim 7, wherein a portion of the cam surface of the shaped recess is linear in profile.

12. The bi-directional indexing device of claim 7, wherein a portion of the cam surface of the cam pin is arcuate in profile.

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