High temperature auto teach calibration disc

Abstract

A robotic arm inserts a calibration disk into a processing chamber. One or more sensors positioned at ports within the processing chamber determine a first position of the calibration disk's center. The calibration disk is then placed on a substrate support within the processing chamber, with features that center it on the substrate support. The robotic arm then removes the calibration disk from the substrate support and the processing chamber. As the calibration disk is removed from the processing chamber, one or more sensors determine a second position of the calibration disk's center. The difference between this first and second position of the calibration disk's center is determined. Based on this difference, an offset to be applied to the robotic arm when placing the wafer onto the substrate support is determined.

Description

Technical Field

[0001] Embodiments of the present disclosure generally relate to methods and systems for calibrating components of an electronic processing system, and more particularly, to calibrating a transfer sequence between components of an electronic processing system. Prior Art

[0002] The calibration and teaching process of stations in electronic processing systems is currently performed at room temperature. This results in a large difference between the temperature of the calibration process and the operating temperature of the station or processing chamber. The increased process temperature causes thermal expansion of components of the station or processing chamber, thereby introducing errors into the calibration values. At operating temperatures exceeding 400°C, some chamber components made of, for example, aluminum may expand by more than 3 mm due to thermal expansion. This results in a low temperature teaching or calibration method with reduced accuracy.

[0003] Current automated calibration and teaching schemes use components including batteries that cannot be exposed to the operating temperature environment because batteries include the risk of swelling or exploding at operating temperatures. This increases the risk of contamination in the station or processing chamber with chemicals from the battery components. Current strategies are also affected by the expensive materials of the calibration objects and sensors.

[0004] An electronic processing system may include one or more robots for transferring a calibration tray from one substrate support of the electronic processing system to another substrate support of the electronic processing system. In the electronic processing system, a substrate or object is moved from one substrate support to another substrate support to a center position of each substrate support. Typically, one or more systematic errors or miscalibrations associated with the first substrate support, the second substrate support, and / or the one or more robots may prevent the robot from placing the substrate or object at a target orientation and position at the second substrate support. Summary of the invention

[0005] The following is a simplified summary of the disclosure to provide a basic understanding of some aspects of the disclosure. This summary is not an extensive overview of the disclosure. It is neither intended to identify the key or important elements of the disclosure nor to delineate any scope of a particular embodiment of the disclosure or any scope of the scope of the invention claims. Its sole purpose is to present some concepts of the disclosure in a simplified form as a prelude to the more detailed description that will be presented later.

[0006] In one aspect of the present disclosure, a method includes inserting a calibration disk into a processing chamber using a robot. The method further includes determining a first position of a center of the calibration disk using one or more sensors positioned at a port of the processing chamber when the calibration disk is inserted into the processing chamber. The method further includes placing the calibration disk on a substrate support within the processing chamber. One or more features of the calibration disk cause the calibration disk to become centered on the substrate support. The method further includes removing the calibration disk from the substrate support and the processing chamber using the robot. The method further includes determining a second position of the center of the calibration disk using the one or more sensors when the calibration disk is removed from the processing chamber. The method further includes determining a difference between the first position of the center of the calibration disk and the second position of the center of the calibration disk. The method further includes determining an offset to be applied to the robot when placing a wafer on the substrate support based on the determined difference.

[0007] In one aspect of the disclosure, a method includes retrieving a calibration disk by a robot within a processing chamber from a first substrate support within the processing chamber. The method further includes using the robot to move the calibration disk to a second substrate support within the processing chamber. The method further includes determining a first position of a center of the calibration disk using one or more sensors positioned between the first substrate support and the second substrate support as the calibration disk is moved between the first substrate support and the second substrate support. The method further includes placing the calibration disk on the second substrate support. One or more features of the calibration disk cause the calibration disk to become centered on the second substrate support. The method further includes retrieving the calibration disk by the robot from the second substrate support. The method further includes using the robot to move the calibration disk to the first substrate support or a third substrate support within the processing chamber. The method further includes determining a second position of the center of the calibration disk using the one or more sensors or one or more additional sensors positioned between the second substrate support and the third substrate support. The method further includes determining a difference between the first position of the center of the calibration plate and the second position of the center of the calibration plate. The method further includes determining an offset to be applied to the robot when placing a wafer onto the second substrate support based on the determined difference.

[0008] In one aspect of the present disclosure, a calibration disk includes a disk-shaped body sized to fit through a slit valve of a processing chamber. The calibration disk further includes at least three arms extending approximately radially from the disk-shaped body, each of the at least three arms including a chamfered edge configured to engage an edge of a substrate support of the processing chamber and guide the calibration disk to a first target position at the substrate support. The calibration disk further includes a second chamfered edge configured to engage an edge of a recess of the substrate support and guide the calibration disk from the first target position at the substrate support to a second target position at which the calibration disk is centered on the substrate support. Simple diagram description

[0009] The present disclosure is illustrated by way of example and not limitation in the figures of the accompanying drawings in which like reference numerals indicate similar elements. It should be noted that different references to "an" or "an" embodiment in the present disclosure are not necessarily to the same embodiment, and such references mean at least one.

[0010] FIG. 1 is a schematic top view of an example electronic processing system according to aspects of the present disclosure.

[0011] FIG. 2 is a schematic top view of an example processing chamber according to aspects of the present disclosure.

[0012] 3A and 3B illustrate an example first orientation and an example initial target orientation of a calibration disk on a substrate support of a processing chamber according to aspects of the present disclosure.

[0013] FIG. 4A illustrates a portion of an example calibration plate positioned on a substrate support according to aspects of the present disclosure.

[0014] FIG. 4B illustrates an example calibration disk according to aspects of the present disclosure.

[0015] 5A-5C illustrate placement of an example calibration tray at a substrate support station according to aspects of the present disclosure.

[0016] FIG. 6 is a flow chart of a method of calibrating placement of a substrate at a substrate support of a processing chamber according to an embodiment of the present disclosure.

[0017] FIG. 7 is a flow chart of a method for calibrating a transfer sequence of a disk between a first station in a processing chamber and a second station in a processing chamber according to an embodiment of the present disclosure.

[0018] FIG. 8 is a block diagram of a computer system according to some embodiments. Implementation

[0019] The calibration and teaching process of a station in an electronic processing system that occurs at room temperature results in a large difference between the temperature of the calibration process and the operating temperature at the station. The elevated process temperature results in thermal expansion of the station components, which introduces errors into the calibration values. This results in low temperature teaching or calibration methods being less accurate than positions taught at operating temperature.

[0020] Methods of calibration and teaching that occur at operating temperatures are more accurate than low temperature (e.g., room temperature) calibration methods. However, sensors typically implemented in these methods use cells that cannot be exposed to high temperatures, such as the operating temperature range, which results in calibration being performed at room temperature. As described in the embodiments herein, methods that utilize thermal expansion of process chamber components at operating temperatures to use physical features of the calibration device to become centered on the substrate support allow for high temperature calibration and position teaching without the use of sensors that are sensitive to high temperatures.

[0021] Embodiments of the present disclosure relate to methods and calibration trays for calibrating one or more components of an electronic processing system at elevated temperatures. In embodiments, multiple components of an electronic processing system are calibrated at operating temperature such that cumulative errors or placement errors caused by or at any of the multiple components are eliminated or reduced. In embodiments described herein, a physical feature of the calibration tray (e.g., a kinematic coupling feature) is used to center the calibration tray on a substrate support at operating temperature. The physical features of the calibration tray cause the tray to become centered on the substrate support. This centering is performed at operating temperature and therefore is performed while components of the substrate support are expanding due to thermal expansion occurring at operating temperature. This results in improved calibration accuracy.

[0022] In some embodiments, a method includes inserting a calibration disk into a processing chamber at an operating temperature using a robot. A sensor placed outside the processing chamber (e.g., at a loading port connected to the processing chamber) determines a first center position of the calibration disk when the calibration disk is inserted into the chamber. In an embodiment, the calibration disk is placed on a substrate support. Features of the calibration disk are such that the calibration disk becomes centered on the substrate support at the operating temperature. The robot that placed the calibration disk on the substrate support can pick up the now centered calibration disk and remove the calibration disk from the processing chamber. A sensor placed outside the processing chamber can again determine a second center position of the substrate when the substrate is removed from the processing chamber. A difference between the first center position and the second center position can be determined. This difference can then be used to determine an offset to be applied to the robot to center the substrates on the substrate support when the substrates are placed at the substrate support. This allows the calibration disk to be centered without exposing the sensors of the electronic sensor disk to the high operating temperatures within the processing chamber.

[0023] In some embodiments, the difference is determined from the difference between the second position of the calibration disk when the calibration disk leaves the processing chamber and the first position of the calibration disk when the calibration disk enters the processing chamber. This allows an offset to be applied to the robot when placing the wafer on the substrate support based on the determined difference. The difference and offset value determined at operating temperature results in higher accuracy, in some embodiments, the offset from the center is within a range of less than 50 microns.

[0024] In one embodiment, a calibration disk is used to determine a difference between a first position of a center of the calibration disk during placement of the calibration disk at a first substrate support in a processing chamber and a second position of the center of the calibration disk during removal of the calibration disk from the first substrate support. The first position may be determined by one or more sensors positioned between the first substrate support and the second substrate support. An offset to be applied to the robot when placing a substrate at the first substrate support may be determined based on the difference between the first position and the second position, such that a substrate (e.g., a wafer) placed at the first substrate support is placed at the center of the first substrate support.

[0025] In one embodiment, a calibration disk is sized to fit through a slit valve of a processing chamber. The calibration disk includes at least three arms extending approximately radially from a disk-shaped body, wherein each arm includes a chamfered edge configured to engage an edge of a substrate support of the processing chamber. These chamfered edges automatically guide the calibration disk to the center of the substrate support and are not hindered by thermal expansion of the material of the disk or the processing chamber due to elevated operating temperatures. In an embodiment, the chamfered edges of the radial arms of the calibration disk adjust the calibration disk from an initial placement to an offset between 1 mm and 3 mm. In an embodiment, the calibration disk further includes a second chamfered edge configured to engage an edge of a recess of the substrate support shaped to receive a substrate. The engagement of the second chamfered edge with the edge of the recess can be used to guide the calibration disk from a first correction position provided by the chamfered edges of the radial arms to a second target position at the substrate support. This second chamfered edge allows the calibration disk to become centered on the substrate support and adjusts the placement of the calibration disk by about 20 microns to about 1 mm. In some embodiments, the chamfered edge has a first lead-in portion that is larger than the lead-in portion for the second chamfered edge. These features enable the calibration disk to be automatically repositioned to the center of the substrate support with greater accuracy than conventional systems.

[0026] In an embodiment, the calibration disk is formed of a solid sintered ceramic that withstands temperatures in excess of 400° C. without damage to the calibration disk or loss of accuracy of the calibration disk. In an embodiment, the calibration disk may have channels to reduce interference with sensors in the processing chamber.

[0027] FIG. 1 is a schematic top view of an example electronic processing system 100 according to one aspect of the present disclosure. The electronic processing system 100 can perform one or more processes on a substrate 102. The substrate 102 can be any suitable rigid, fixed-size planar article, such as, for example, a silicon-containing disk or wafer, a patterned wafer, a glass plate, or the like, suitable for manufacturing electronic devices or circuit components thereon.

[0028] The electronic processing system 100 may include a mainframe 104 and a factory interface 106 coupled to the mainframe 104. The mainframe 104 may include a housing 108 having a transfer chamber 110 therein. The transfer chamber 110 may include one or more processing chambers (also referred to as process chambers) 114, 116a, 116b, 118a, 118b disposed thereabout and coupled thereto. The processing chambers 114, 116a, 116b, 118a, 118b may be coupled to the transfer chamber 110 via respective ports 131, which may include slit valves or the like.

[0029] It should be noted that a generally square main frame having four sides (also referred to as faces) is shown, wherein a plurality of process chambers are coupled to each face. However, it should be understood that a face may include a single process chamber or more than two process chambers coupled thereto. Additionally, the main frame 104 may have other shapes, such as a rectangular shape (where different faces may have different lengths) or a radial shape having more than four faces (e.g., having five, six, or more faces).

[0030] The processing chambers 114, 116a, 116b, 118a, 118b may be adapted to perform any number of processes on the substrate 102. The same or different substrate processes may be performed in each of the processing chambers 114, 116a, 116b, 118a, 118b. The substrate processes may include atomic layer deposition (ALD), physical vapor deposition (PVD), chemical vapor deposition (CVD), etching, annealing, curing, pre-cleaning, metal or metal oxide removal, or the like. In one example, a PVD process may be performed in one or both of the processing chambers 114, an etching process may be performed in one or both of the processing chambers 116a, 116b, and an annealing process may be performed in one or both of the processing chambers 118a, 118b. Other processes may be performed on the substrates therein. The processing chambers 114, 116a, 116b, 118a, 118b may each include a substrate support assembly. The substrate support assembly may be configured to hold a substrate in place while a substrate process is being performed. In some embodiments, one or more processing chambers (e.g., processing chambers 116a, 116b, 118a, 118b) may include a single station (e.g., a single substrate support). In some embodiments, one or more processing chambers 114 may include multiple stations (e.g., multiple substrate supports. In some embodiments, the processing chambers include 2, 3, 4, or more substrate supports. In some embodiments, multiple ports couple the processing chambers 114 to a transfer chamber.

[0031] The transfer chamber 110 may also include a transfer chamber robot 112. The transfer chamber robot 112 may include one or more robotic arms, wherein each robotic arm includes one or more end effectors (also referred to herein as blades) at the end of the robotic arm. The end effectors may be configured to handle specific objects, such as wafers and / or other substrates. In some embodiments, the transfer chamber robot 112 may be a selective compliance assembly robot arm (SCARA) robot, such as a 2-link SCARA robot, a 3-link SCARA robot, a 4-link SCARA robot, etc. In some embodiments, the transfer chamber robot 112 may not be calibrated to a substrate support (also referred to as a substrate station) in one or more of the processing chambers 114, 116a-b, 118a-b. Therefore, in an embodiment, a calibration process may be performed to calibrate the transfer chamber robot 112 to one or more substrate supports of one or more processing chambers 114, 116a-b, 118a-b. Once the transfer chamber robot 112 is calibrated to the substrate support, the transfer chamber robot 112 can accurately place the substrate in the center of the substrate support.

[0032] In some embodiments, ports 131 and / or slit valves are at the interface between processing chambers 114, 116a, 116b, 118a, 118b and transfer chamber 110. A local center finder (LCF) 150 may be positioned at or near each such port 131 or slit valve. Each local center finder 150 is configured to determine the center of an object (e.g., a ring, a wafer, a substrate, etc.) passing through an associated port 131 or slit valve. LCF 150 may include an arrangement of laser and detector pairs. Each laser may project a laser beam that may be received by a corresponding detector in the laser and detector pair. In embodiments, the laser directs the laser beam vertically or at an angle relative to vertical. Each detector is positioned in the path of the laser beam from the corresponding laser. When an object (e.g., a calibration object, such as a calibration disk, substrate, wafer, etc.) passes through port 131 or a slit valve, it blocks the laser beam so that the laser beam is not received by the detector. Based on known information about the size and shape of the calibration object or other object passing through port 131 or a slit valve, known information about the positions of the laser and the detector, and known information about the respective positions of the transfer chamber robot 112, the center of the calibration object or other known object can be determined at which respective positions each of the respective detectors stops receiving the laser beam. Other types of LCFs can also be used, such as camera-based local center detectors and / or runout ribbon-based local center detectors. Such information can be used in embodiments to perform calibration of the transfer chamber robot 112 and substrate supports in chambers 114, 116a, 116b, 118a, 118b.

[0033] One or more load locks 120a, 120b may also be coupled to the housing 108 and the transfer chamber 110. The load locks 120a, 120b may be configured to interface and couple to the transfer chamber 110 on one side and to the factory interface 106 on the other side. In some embodiments, the load locks 120a, 120b may have an environmentally controlled atmosphere that may be changed from a vacuum environment (where substrates may be transferred to and from the transfer chamber 110) to an environment at or near atmospheric pressure (e.g., with an inert gas) (where substrates may be transferred to and from the factory interface 106). In some embodiments, the one or more load locks 120a, 120b may be a stacked load lock having one or more upper interior chambers and one or more lower interior chambers at different vertical levels (e.g., one above the other). In some embodiments, a pair of upper interior chambers are configured to receive processed substrates from the transfer chamber 110 for removal from the main frame 104, and a pair of lower interior chambers are configured to receive substrates from the factory interface 106 for processing in the main frame 104. In some embodiments, one or more load locks 120a, 120b may be configured to perform a substrate process (e.g., etching or pre-cleaning) on one or more substrates 102 received therein.

[0034] In an embodiment, ports 133 and / or slit valves separate the transfer chamber 110 from the load locks 120a, 120b. LCFs 152 are positioned at or near each such port 133 and / or slit valve. The LCFs may be used to determine the center of an object (e.g., a calibration object, a wafer, a substrate, etc.) on the robot 112 while the robot 112 places such an object in or removes such an object from the load lock.

[0035] The factory interface (FI) 106 may be any suitable housing, such as, for example, an Equipment Front End Module (EFEM). The factory interface 106 may be configured to receive substrates 102 from substrate carriers 122 (e.g., Front Opening Unified Pods (FOUPs)) docked at various load ports 124 of the factory interface 106. A factory interface robot 126 (shown in dashed lines) may be configured to transfer substrates 102 between the substrate carrier (also referred to as a container) 122 and the load lock 120. The factory interface robot 126 may include one or more robotic arms, and may be or include a SCARA robot. In some embodiments, the factory interface robot 126 may have more links and / or more degrees of freedom than the transfer chamber robot 112. The factory interface robot 126 may include end effectors on the ends of each robotic arm. The end effectors may be configured to pick up and carry specific objects, such as wafers. Alternatively or additionally, the end effector may be configured to handle objects such as calibration trays or other calibration objects.

[0036] Any conventional robot type may be used for the factory interface robot 126. The transfer may be performed in any order or direction. In some embodiments, the factory interface 106 may be maintained in a non-reactive gas environment, such as a slightly positive pressure (using, for example, nitrogen as the non-reactive gas).

[0037] In some embodiments, a side storage pod (SSP, not shown) is coupled to FI 106.

[0038] The substrate carrier 122 and the load port 124, the substrate carrier 122, the load locks 120a, 120b, the SSP, and the processing chambers 114, 116a, 116b, 118a, 118b are each considered to be or include substrate supports herein. In some embodiments, the transfer chamber 110, the process chambers 114, 116a, 116b and 118a, 118b, and the load lock 120 can be maintained at a vacuum level. The electronic processing system 100 can include one or more ports 130, 131, 133 (e.g., vacuum ports) coupled to one or more stations of the electronic processing system 100. For example, the port 130 (e.g., vacuum port) can couple the factory interface 106 to the load lock 120. As described above, an additional port 133 (e.g., vacuum port) can be coupled to the load lock 120 and disposed between the load lock 120 and the transfer chamber 110. Each of the ports 130 , 133 , 131 may include a slit valve that separates a vacuum environment from a higher pressure (eg, atmospheric pressure) environment.

[0039] The electronic processing system 100 may also include a system controller 132. The system controller 132 may be and / or include a computing device, such as a personal computer, a server computer, a programmable logic controller (PLC), a microcontroller, etc. The system controller 132 may include one or more processing devices, which may be general-purpose processing devices, such as a microprocessor, a central processing unit, or the like. More specifically, the processing device may be a complex instruction set computing (CISC) microprocessor, a reduced instruction set computing (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, or a processor that implements other instruction sets, or a processor that implements a combination of instruction sets. The processing device may also be one or more special-purpose processing devices, such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal processor (DSP), a network processor, or the like. The system controller 132 may include data storage devices (e.g., one or more disk drives and / or solid state drives), main memory, static memory, network interfaces, and / or other components. The system controller 132 may execute instructions to perform any one or more of the methods and / or embodiments described herein. The instructions may be stored on a computer readable storage medium, which may include main memory, static memory, auxiliary storage, and / or a processing device (during execution of the instructions). The system controller 132 may also be configured to allow an operator to input and display data, operating commands, or the like.

[0040] In some embodiments, the system controller 132 causes the electronic processing system 100 to perform one or more calibration procedures to generate calibration data (e.g., characteristic error values) associated with one or more stations (e.g., substrate supports), one or more robots, and / or one or more wafer transfer sequences. The system controller 132 stores the calibration values (e.g., characteristic error values) in one or more data storage devices.

[0041] FIG. 1 schematically illustrates the transfer of the calibration tray 136 into the processing chambers 114 , 116a , 116b , 118a , 118b .

[0042] According to one aspect of the present disclosure, the calibration tray 136 is removed from a substrate carrier 122 (e.g., FOUP) or SSP via a factory interface robot 126 located in the factory interface 106, or alternatively is directly loaded into the factory interface 106. In some embodiments, the system controller 132 determines a transfer recipe for the calibration tray 136. The transfer recipe may indicate a transfer path for the calibration tray 136 to follow when transferring from the substrate carrier 122 or SSP to a particular processing chamber 114, 116a, 116b, 118a, 118b.

[0043] The calibration disk 136 may include a flat surface or a notch that will align with a corresponding flat surface in the substrate support assembly around which the calibration disk 136 will be placed in the processing chamber. Alternatively, the calibration disk 136 may not include a flat surface or a notch, and the orientation of the calibration disk 136 may not be considered. In an ideal arrangement, the calibration disk 136 will be centered on the substrate support when placed on the substrate support by the robot 112, without robot position and / or rotation errors, without misalignment of the processing chamber relative to the transfer chamber, etc. However, different robot errors may occur for each of the processing chambers in which the calibration disk 136 is placed. In addition, one or more of the processing chambers may have a slight misalignment or misalignment. The embodiments described herein provide a calibration procedure to correct for any such robot errors, misalignments, and / or misalignments, as described more fully below.

[0044] The transfer chamber robot 112 may remove the calibration tray 136 from the load lock 120b via the second vacuum port 130b. The transfer chamber robot 112 may move the calibration tray 136 into the transfer chamber 110, where the object may be transferred to a destination station (e.g., a substrate support of a processing chamber 114, 116a, 116b, 118a, 118b). The LCF associated with the processing chamber 114, 116a, 116b, 118a, 118b may measure the center of the calibration tray 136 when the calibration tray is inserted into the process chamber. The calibration tray 136 may be placed in a destination station (e.g., a substrate support of a processing chamber 114, 116a, 116b, 118a, 118b).

[0045] In an embodiment, when the transfer chamber robot 112 places the calibration disk 136 on a substrate support of a process chamber 114, 116a, 116b, 118a, 118b, the transfer chamber robot 112 uses the taught position of the robot arm of the transfer chamber robot 112 to nominally place the calibration disk 136 at a first target position on the substrate support. The first target position may be at the center of the substrate support, or may be at a position offset from the center of the substrate support. The calibration disk 136 may have one or more physical features (e.g., a kinematic coupler) that cause the calibration disk 136 to become centered on the substrate support even if the calibration disk 136 is not initially placed at the center of the substrate support. The robot 112 may retrieve the calibration disk 136 from the calibration support, and the LCF 150 may measure the center of the calibration disk when the calibration disk is removed from the process chamber. In an embodiment, the system controller 132 receives a first measurement of the center of the calibration disk 136 measured when the calibration disk is inserted into the process chamber and a second measurement of the center of the calibration disk measured when the calibration disk is removed from the process chamber. The system controller 132 may then calculate an offset between the first measurement and the second measurement, and may use the calculated offset to update the taught position of the robot 112 to place the substrate in the process chamber. The new taught position for the robot 112 may cause the substrate to be placed in the center of the substrate support for the process chamber. This process may be performed for each process chamber and / or each substrate support to calibrate the robot 112 to each substrate support and / or substrate support in the process chamber.

[0046] Calibration of the teach position of the transfer chamber robot 112 for transferring substrates to a process chamber is discussed in more detail below with reference to FIG. 6 .

[0047] FIG. 2 shows an example of a processing chamber 200 having four substrate stations 240a-d. Alternatively, the processing chamber 200 may include more or fewer substrate stations. One or more processes may be performed on a substrate at each of the substrate stations 240a-d. In embodiments, the same or different operations may be performed at each of the substrate stations 240a-d. In some embodiments, the processing chamber 200 may correspond to the processing chamber 114 of FIG. 1.

[0048] In some embodiments, one or more substrate stations 240a-d of the processing chamber 200 may be accessed by the transfer chamber robot 230 via one or more ports of the processing chamber 200. When the calibration disk is inserted into the processing chamber 200, a first position of the center of the calibration disk 250 may be determined by one or more sensors 210a-b (e.g., of the LCF) positioned at the ports of the processing chamber 200.

[0049] In an embodiment, the calibration disk 250 may include arms extending from the center of the disk, the arms including chamfered edges 260. When the chamfered edges 260 of the calibration disk 250 interact with the substrate support 240, the location of the chamfered edges 260 of the calibration disk 250 causes the calibration disk 250 to move in the x-direction and the y-direction on the surface of the substrate support 240 such that the calibration disk moves to the center of the substrate support 240.

[0050] The calibration tray 250 may then be removed from the substrate support station 240 using the transfer chamber robot. A second position of the calibration tray 250 is then determined when the calibration tray 250 is removed from the processing chamber 200. A difference between the first position of the calibration tray 250 and the second position of the calibration tray 250 may be determined, and an offset to be applied to the robot 230 when placing a wafer onto the substrate support 240 may be determined based on the determined difference.

[0051] In some embodiments, the processing chamber 200 may include a process chamber robot 230 having one or more arms 265a-d (e.g., four arms) oriented and configured to move objects (e.g., calibration trays, wafers, etc.) between substrate support stations 240 within the processing chamber 200. In some embodiments, the robot 230 may rotate to move substrates between the substrate stations 240a-d. In some embodiments, the one or more robotic arms 265a-d of the robot 230 may not be calibrated to one or more of the substrate stations 240a-d. Therefore, a calibration process may be performed to calibrate the robot 230 (or one or more arms 265a-d of the robot 230) to the substrate stations 240a-d.

[0052] In addition to or instead of calibrating the transfer chamber robot to the substrate station locations, the process chamber robot 230 (or one or more arms 265a-d of the process chamber robot 230) may be calibrated to one or more substrate stations 240a-d of the processing chamber 200 using techniques similar to those described with reference to calibrating the transfer chamber robot to the substrate stations 240a-d.

[0053] In some embodiments, the calibration disk 250 is retrieved by the process chamber robot 230 from an initial support station (e.g., support station 240a) where the calibration disk 250 was previously placed. The calibration disk 250 may be transferred to a second substrate station (e.g., substrate station 240b) within the processing chamber 200 using the process chamber robot 230. As the calibration disk 250 is transferred 270 between the first substrate support 240a and the second substrate support 240b, a first position of the calibration disk 250 may be determined using one or more sensors 220 (e.g., of an LCF) positioned between the first substrate support 240a and the second substrate support 240b. The calibration disk 250 is then placed on the second substrate support 240b, and the chamfered edge 260 of the calibration disk 250 may interact with the substrate support 240b to move the calibration disk 250 in the x-direction and the y-direction on the surface of the substrate support 240b such that the calibration disk moves to the center of the substrate station 240b.

[0054] The calibration disk 250 is then retrieved by the main frame robot 230 and moved to either the first substrate station 240a or the third substrate station 240c. If the calibration disk 250 is moved back to the first substrate station 240a, one or more sensors 220a (e.g., LCF) between the two substrate stations may be used to again determine the new center of the calibration disk 250. If the calibration disk 2650 is moved to the third substrate station 240c, the sensors 220b (e.g., of another LCF) between the second and third substrate stations determine the new center of the calibration disk 250. The difference between the first position of the center of the calibration disk and the second or new position of the center of the calibration disk is then determined. This difference is then applied as an offset to the process chamber robot 230 when a wafer is placed on the second substrate support 240b. A similar process may be performed to determine the offsets applied to the arms 265a-d of the robot 230 when substrates are placed at each of the other substrate stations 240c, 240d, 240a.

[0055] FIG. 3A illustrates an example first position 316 of a calibration disk 324 at a substrate support of a processing chamber according to aspects of the present disclosure. The processing chamber may correspond to at least one of the processing chambers 114, 116a, 116b, or 118a, 118b of the electronic processing system 100 shown in FIG. 1 . In some embodiments, the processing chamber may include a substrate support 310 configured to support a substrate during a substrate process. The calibration disk 324 may be configured to be placed on the substrate support assembly 310. As previously described, the calibration disk 324 may be placed at the first position 316 at the substrate support 310 by a transfer chamber robot (not shown) or a process chamber robot. In some embodiments, the first position 316 may include a position error. The position error may include a first position error 325 along the x-axis and / or a second position error 330 along the y-axis. The position error may indicate a difference between an actual position of the calibration disk 310 and a target position (e.g., where the calibration disk 324 may be centered at the target position). The first position error 325 may be caused by a first characteristic error value in the y-direction, and the second position error 330 may be associated with a second characteristic error value in the x-direction. Characteristic errors may be caused by a variety of sources (e.g., errors in robot angles and / or positioning, processing chambers not being properly installed during configuration of the processing system, etc.).

[0056] FIG. 3B illustrates an example position 318 of a calibration disk 324 at a processing chamber according to aspects of the present disclosure. The position 318 can be the correct orientation and position for placing the calibration disk 324 at the substrate support 310. In some embodiments, the position 318 in the processing chamber can be automatically achieved by calibration features of the calibration disk 324 that automatically center the calibration disk on the substrate support 310.

[0057] FIG. 4A illustrates an example calibration disk 420 on a substrate support 410 of a station according to aspects of the present disclosure. The calibration disk 420 includes a ceramic disk-shaped body having three or more arms 430. The arms 430 include chamfered edges 432 that center the calibration disk on the substrate support 410. In an embodiment, the chamfered edge 432 of the calibration disk may include a slope of approximately 45 degrees. In other embodiments, different slopes may be used for the chamfered edge, such as 30 degrees, 15 degrees, 60 degrees, 85 degrees, and / or any other angle or slope.

[0058] FIG. 4B illustrates the surface of the bottom of the calibration disk 420. In an embodiment, the calibration disk 420 may include at least three arms 430 extending radially from the disk-shaped body. Each of the at least three arms 430 may include a chamfered edge 432 configured to engage with an edge of the substrate support 410. The chamfered edges 432 of the at least three arms 430 may be configured to guide the calibration disk to a first target position at the substrate support 410. The disk-shaped body may further include a second chamfered edge to engage with an edge of the recess 422 of the substrate support 410 to guide the calibration disk 420 from the first target position at the substrate support to a second target position where the calibration disk 420 is centered on the substrate support 410. In some embodiments, the second edge may not be chamfered. In an embodiment, the calibration disk 420 may include a shape that is the negative of a second shape of the surface of the substrate support 410 (e.g., of the recess 422).

[0059] In an embodiment, the chamfered edge 432 of the calibration disk 420 may include a first lead-in portion, and the second chamfered edge (not shown) may include a second lead-in portion that is smaller than the first lead-in portion. The disk-shaped body of the calibration disk 420 and the at least three arms 430 may be part of a solid sintered ceramic product that can be used at temperatures up to about 400° C. without damaging the calibration disk 420.

[0060] In some embodiments, the calibration disk 420 can be configured to thermally expand at the operating temperature of the processing chamber. The calibration disk 420 can be further configured to be used to calibrate the processing chamber at the operating temperature.

[0061] FIGS. 5A-5C illustrate placement of an example calibration disk 530 on a substrate support 510 according to aspects of the present disclosure. In FIG. 5A , a plurality of lift pins 520 (only one lift pin is shown) are extended and engage with the calibration disk 530. In FIG. 5B , the lift pins 520 are lowered and a first feature 535 (e.g., a first chamfered edge) of at least one of the three arms is used to correct for positional errors of the calibration disk 530 when this first feature engages with an outer edge of the substrate support 510. In some embodiments, the first feature 535 may be a kinematic coupling interface. In some embodiments, the first feature 535 on the arm may correct for total error. In some embodiments, the outer edge of the substrate support 510 is chamfered (e.g., has a slope similar to that of the first feature 535). In some embodiments, the outer edge of the substrate support 510 is not chamfered.

[0062] FIG. 5C shows the interface between the calibration disk 530 and the substrate support 510 when the lift pins 520 have fully lowered the calibration disk 530 and the second feature 540 of the calibration disk 530 has acted on the substrate support 510 to center the calibration disk 530. In an embodiment, the second feature 540 may include a second chamfered edge of the body of the calibration disk. In an embodiment, the second feature 540 may correct for minor errors in the centering of the calibration disk 530 on the substrate support 510. In some embodiments, the second feature 540 engages an edge of a recess 550 of the substrate support 510 configured to receive a substrate such as a wafer. In some embodiments, the calibration disk 530 may have a shape that is the negative of a second shape of the surface of the substrate support 510. In some embodiments, the edge of the recess 550 of the substrate support 510 is chamfered (e.g., has a slope similar to the first feature 540). In some embodiments, the edge of the recess 550 of the substrate support 510 is not chamfered, or has a different slope or angle than the chamfer of the second feature 540.

[0063] FIG6 and FIG7 are flow charts of various embodiments of methods 600-700 for calibrating components and / or transfer sequences of an electronic processing system and / or for transferring objects between components of an electronic processing system using characteristic error values determined based on calibration. These methods are performed by processing logic, which may include hardware (circuitry, dedicated logic, etc.), software (such as running on a general purpose computer system or a dedicated machine), firmware, or some combination thereof. Some operations of methods 600-700 may be performed or initiated by a computing device (such as system controller 132 of FIG1).

[0064] For ease of explanation, these methods are depicted and described as a series of actions. However, the actions according to the present disclosure may occur in various orders and / or simultaneously, and with other actions not presented and described herein. Furthermore, not all of the actions shown may be performed to implement the methods according to the disclosed subject matter. Furthermore, those skilled in the art will understand and appreciate that these methods may alternatively be represented as a series of related states via state diagrams or events.

[0065] FIG. 6 is a flow chart of a method 600 for calibrating a transfer sequence between a transfer chamber robot and a substrate support of a processing chamber according to an embodiment of the present disclosure. At block 610, a heater heats the processing chamber to an operating temperature. In embodiments, the operating temperature may include a range of up to 400° C., up to 600° C., or another elevated temperature above room temperature. At block 620, a calibration disk is retrieved by a first robot of the transfer chamber and inserted into the processing chamber. At block 630, a first position of a center of the calibration disk is determined using one or more sensors positioned at a port of the processing chamber when the calibration disk is inserted into the processing chamber.

[0066] At block 640, the calibration disk is placed on a substrate support within a processing chamber. In response to being placed on the substrate support, one or more features of the calibration disk cause the calibration disk to become centered on the substrate support. In an embodiment, the features may include a first chamfered edge of one of at least three arms of the calibration disk, and a second chamfered edge configured to engage with a recess of the substrate support. At block 650, the calibration disk is removed from the substrate support and the processing chamber using a robotic arm.

[0067] At block 660, a second position of the center of the calibration disk is determined using one or more sensors when the calibration disk is removed from the processing chamber. At block 670, a difference between the first position of the center of the calibration disk and the second position of the center of the calibration disk is determined.

[0068] At block 680, an offset to be applied to the robot when placing the wafer onto the substrate support is determined based on the determined difference. At block 690, the wafer may be inserted into the processing chamber and onto the first substrate support using the determined offset.

[0069] FIG. 7 is a flow chart of a method 700 for calibrating a transfer sequence between a plurality of substrate supports within a processing chamber of an electronic processing system according to an embodiment of the present disclosure. At block 710, a heater heats the processing chamber to an operating temperature. In an embodiment, the operating temperature may include a range up to 400° C. or another elevated temperature. At block 720 of method 700, a robot within the process chamber retrieves a calibration tray from a first substrate support within the processing chamber.

[0070] At block 730, the calibration disk is transferred to a second substrate support within the processing chamber using the robot arm. At block 740, a first position of a center of the calibration disk is determined using one or more sensors positioned between the first substrate support and the second substrate support as the calibration disk is transferred between the first substrate support and the second substrate support.

[0071] At block 750, the calibration disk is placed on the second substrate support. In response to being placed on the second substrate support, one or more features of the calibration disk cause the calibration disk to become centered on the second substrate support. At block 760, the calibration disk is retrieved from the second substrate support by the robot. At block 770, the calibration disk is moved to the first substrate support or the third substrate support within the processing chamber using the robot.

[0072] At block 775, a second position of the center of the calibration disk is determined using one or more sensors or one or more additional sensors positioned between the second substrate support and the third substrate support. At block 780, a difference between the first position of the center of the calibration disk and the second position of the center of the calibration disk is determined. At block 785, an offset to be applied to the robot when placing the wafer on the second substrate support is determined based on the determined difference. At block 790, the wafer is retrieved from the first substrate support by the robot. At block 795, the wafer may be placed at the second substrate support by the robot using the determined offset. The method 700 may be repeated for one or more additional substrate supports of the processing chamber until the process chamber robot has been properly calibrated to all substrate supports of the processing chamber.

[0073] FIG. 8 is an example computing device 800 that can operate as a system controller for an electronic processing system according to an embodiment of the present disclosure. The computing device 800 is a machine in which a set of instructions for causing the machine to perform any one or more of the methods discussed herein can be executed. In alternative embodiments, the machine can be connected (e.g., networked) to other machines in a local area network (LAN), an intranet, a business network, or the Internet. The machine can operate as a server or client machine in a client-server network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. The machine can be a personal computer (PC), a tablet, a network appliance, a server, a network router, a switch or a bridge, or any machine capable of executing (sequentially or otherwise) a set of instructions that specify actions to be taken by the machine. In addition, although only a single machine is shown, the term "machine" should also be construed to include any collection of machines (e.g., computers) that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methods discussed herein. In one embodiment, computing device 800 corresponds to system controller 132 of FIG. 1 . In one embodiment, system controller 132 is a component of computing device 800 .

[0074] The example computing device 800 includes a processing device 802, a main memory 804 (e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM), etc. (such as synchronous DRAM (SDRAM) or Rambus DRAM (RDRAM))), a static memory 806 (e.g., flash memory, static random access memory (SRAM), etc.), and an auxiliary memory (e.g., a data storage device 812) that communicate with each other via a bus 808.

[0075] Processing device 802 represents one or more general-purpose processors, such as a microprocessor, a central processing unit, or the like. More specifically, processing device 802 may be a complex instruction set computing (CISC) microprocessor, a reduced instruction set computing (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, a processor implementing other instruction sets, or a processor implementing a combination of instruction sets. Processing device 802 may also be one or more special-purpose processing devices, such as an application specific integrated circuit (ASIC), a field programmable gate array (FPGA), a digital signal processor (DSP), a network processor, or the like. Processing device 802 is configured to execute processing logic (instructions 822) for performing the operations discussed herein. In one embodiment, system controller 132 corresponds to processing device 802. In an embodiment, processing device 802 executes instructions 826 to implement any of methods 600-700 in an embodiment.

[0076] The computing device 800 may further include a network interface device 808. The computing device 800 may also include a video display unit 810 (e.g., a liquid crystal display (LCD) or a cathode ray tube (CRT)), an alphanumeric input device 812 (e.g., a keyboard), a cursor control device 814 (e.g., a mouse), and a signal generating device 816 (e.g., a speaker).

[0077] The data storage device 818 may include a machine-readable storage medium (or more specifically, a computer-readable storage medium) 828 on which one or more sets of instructions 822 are stored, which embody any one or more of the methods or functions described herein. During the execution of the instructions 822 by the computer system 800, these instructions may also reside completely or at least partially in the main memory 804 and / or in the processing device 802, and the main memory 804 and the processing device 802 also constitute computer-readable storage media.

[0078] The computer-readable storage medium 828 may also be used to store instructions 826 and / or characteristic error values (e.g., offsets for placing a substrate at a substrate support in a process chamber) 850, as discussed above. Although the computer-readable storage medium 828 is shown as a single medium in the example embodiment, the term "computer-readable storage medium" should be taken to include a single medium or multiple media (e.g., a centralized or distributed database, and / or associated caches and servers) storing one or more sets of instructions. The term "computer-readable storage medium" should also be taken to include any medium other than a carrier wave that is capable of storing or encoding a set of instructions for execution by a machine and causing the machine to perform any one or more of the methods described herein. Thus, the term "computer-readable storage medium" should be taken to include, but is not limited to, non-transitory media (including solid-state memory), as well as optical and magnetic media.

[0079] References throughout this specification to "one embodiment" or "an embodiment" indicate that a particular feature, structure, or characteristic described in connection with the embodiment is included in at least one embodiment. Thus, the phrases "in one embodiment" or "in an embodiment" appearing in various places throughout this specification are not necessarily referring to the same embodiment. In addition, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or". When the term "about" or "approximately" is used herein, this is intended to mean that the nominal value presented is accurate to within ±10%.

[0080] Although the operations of the methods herein are shown and described in a particular order, the order of the operations of each method may be changed, such that certain operations may be performed in a reverse order, such that certain operations may be performed at least partially simultaneously with other operations. In another embodiment, instructions or sub-operations of different operations may be performed in an intermittent and / or alternating manner.

[0081] The foregoing description sets forth many specific details, such as examples of specific systems, components, methods, etc., in order to provide a good understanding of several embodiments of the present disclosure. However, it will be apparent to those skilled in the art that at least some embodiments of the present disclosure may be practiced without these specific details. In other cases, well-known components or methods are not described in detail or are presented in a simple block diagram format to avoid unnecessarily obscuring the present disclosure. Therefore, the specific details set forth are merely illustrative. Specific implementations may differ from these illustrative details and still be contemplated as being within the scope of the present disclosure.

[0082] It should be understood that the above description is intended to be illustrative, not restrictive. Many other embodiments will be apparent to those skilled in the art after reading and understanding the above description. Therefore, the scope of the present disclosure should be determined by reference to the appended claims and the full scope of equivalents to which such claims are entitled.

[0083] 100: Electronic processing system 102:Substrate 104: Main frame 106: Factory Interface, Factory Interface (FI), FI 108: Shell 110: Transfer chamber 112: Transfer chamber robot, robotic arm, robot 114: Processing chamber, process chamber, chamber 116a: processing chamber, process chamber, chamber 116b: processing chamber, process chamber, chamber 118a: processing chamber, process chamber, chamber 118b: processing chamber, process chamber, chamber 120a: Loading lock 120b: Loading lock 122: substrate carrier 124: Loading port 126: Factory Interface Robot 130: Port 131: Port 132: System Controller 133: Port 136: Calibration plate 150: Local Center Detector (LCF), Local Center Detector, LCF 152:LCF 200: Processing chamber 210a: Sensor 210b: Sensor 220a: Sensor 220b: Sensor 220c: Sensor 220d: Sensor 230: Transfer chamber robot, robotic arm, process chamber robot, robot, main frame robot 240a: substrate station, first substrate support, first substrate station 240b: substrate station, second substrate support, substrate support 240c: third substrate station, substrate station 240d: Substrate Station 250: Calibration plate 260: Chamfered edge 265a: arm, robotic arm 265b: arm, robotic arm 265c: arm, robotic arm 265d: arm, robotic arm 270: Transfer 310: substrate support, calibration plate 316: First position 318: Location 320: 324: Calibration plate 325: First position error 330: Second position error 400: 410: substrate support 420: Calibration plate 422: Concave 430: Arm 432: Chamfered edge 510: substrate support 520: Lifting pin 530: Calibration plate 535: First feature 540: Second feature 550: Concave 600: Method 610: Block 620: Block 630: Block 640: Block 650: Block 660: Block 670: Block 680: Block 690: Block 700: Method 710: Block 720: Block 730: Block 740: Block 750: Block 760: Block 770: Block 775: Block 780: Block 785: Block 790: Block 795: Cube 800: Computing devices, computer systems 802: Processing device 804: Main memory 806: Static Memory 808: Bus, Network Interface Device 810: Video display unit 812: Data storage device, alphanumeric input device 814: Cursor control device 816: Signal generating device 820: Signal generating device 822: Instructions 824: Computer readable media 826: Instructions 828: Machine readable storage media, computer readable storage media 850: Characteristic error value 864: Internet

Claims

1. A method of using a calibration disk, comprising the steps of: inserting the calibration disk into a processing chamber using a robotic arm; determining a first position of a center of the calibration disk using one or more sensors positioned at a port in the processing chamber while the calibration disk is inserted into the processing chamber; placing the calibration disk on a substrate support within the processing chamber, wherein one or more features of the calibration disk cause the calibration disk to be centered on the substrate support; removing the calibration disk from the substrate support and from the processing chamber using the robotic arm; determining a second position of the center of the calibration disk using one or more sensors while the calibration disk is removed from the processing chamber; determining a difference between the first position and the second position of the center of the calibration disk; and determining an offset to be applied to the robotic arm when a wafer is placed on the substrate support based on the determined difference.

2. The method as claimed in claim 1, wherein the calibration disk is not initially placed at a center of the substrate support, and wherein the one or more features include a first plurality of chamfered edges, the first chamfered edges aligning at least partially the center of the calibration disk with the center of the substrate support.

3. The method as described in claim 2, wherein the one or more features further include a second plurality of chamfered edges, the second plurality of chamfered edges aligning the center of the calibration disk with the center of the substrate support.

4. The method as claimed in claim 1, further comprising the steps of: heating the processing chamber to an operating temperature before inserting the calibration disk into the processing chamber, wherein the calibration disk thermally expands within the processing chamber, and wherein one or more features of the calibration disk cause the calibration disk to become centered on the substrate support at the operating temperature.

5. The method as described in claim 4, wherein the operating temperature is between about 20°C and about 500°C.

6. The method of claim 1, wherein the one or more sensors include a plurality of laser emitters for emitting a plurality of light beams and a plurality of receivers for receiving the light beams, wherein a controller is configured to determine a first position of the center of the calibration disk based on one or more positions of the robotic arm and readings for the one or more positions of the robotic arm, the readings indicating that a receiver among the receivers has detected one of the light beams and that a receiver among the receivers has not detected any of the light beams.

7. The method as described in claim 1, further comprising the steps of: inserting a wafer into the processing chamber and onto the substrate support using the determined offset.

8. A method of using a calibration disk, comprising the steps of: retrieving the calibration disk from a first substrate support within a processing chamber by a robotic arm; transferring the calibration disk to a second substrate support within the processing chamber using the robotic arm; determining a first position of a center of the calibration disk using one or more sensors positioned between the first and second substrate supports while the calibration disk is transferred between the first and second substrate supports; placing the calibration disk on the second substrate support, wherein one or more features of the calibration disk center the calibration disk on the second substrate support; retrieving the calibration disk from the second substrate support by a robotic arm; transferring the calibration disk to the first or third substrate support within the processing chamber using the robotic arm; determining a second position of the center of the calibration disk using one or more sensors or one or more additional sensors positioned between the second and third substrate supports; Determine a difference between a first position of the center of the calibration disk and a second position of the center of the calibration disk; and determine, based on the determined difference, an offset to be applied to the robotic arm when the wafer is placed on the second substrate support.

9. The method as described in claim 8, further comprising the steps of: retrieving a wafer from the first substrate support by the robotic arm; and placing the wafer at the second substrate support by the robotic arm using a determined offset.

10. The method of claim 8, wherein the calibration disk is not initially placed at a center of the first substrate support, and wherein the one or more features include a first plurality of chamfered edges, the first chamfered edges aligning at least partially the center of the calibration disk with the center of the first substrate support.

11. The method as described in claim 10, wherein the one or more features further include a second plurality of chamfered edges, the second chamfered edges aligning the center of the calibration disk with the center of the substrate support.

12. The method as claimed in claim 8, further comprising the steps of: heating the processing chamber to an operating temperature, wherein the calibration disk thermally expands within the processing chamber, and wherein one or more features of the calibration disk cause the calibration disk to become centered on the second substrate support at the operating temperature.

13. The method as described in claim 12, wherein the operating temperature is between about 20°C and about 500°C.

14. The method of claim 8, wherein the calibration disk is transferred to the third substrate support, the method further comprising the steps of: retrieving the calibration disk from the third substrate support by the robotic arm; transferring the calibration disk to a fourth substrate support within the processing chamber using the robotic arm; determining a third position of the center of the calibration disk using one or more additional sensors positioned between the third substrate support and the fourth substrate support; determining a second difference between the second position of the center of the calibration disk and the third position of the center of the calibration disk; and determining a second offset to be applied to the robotic arm when the wafer is placed on the third substrate support based on the second difference.

15. A calibration disk comprising: a disk-shaped body sized to fit through a slit valve in a processing chamber; and at least three arms extending approximately radially from the disk-shaped body, each of the at least three arms including a chamfered edge configured to engage with an edge of a substrate support of the processing chamber and guide the calibration disk to a first target position on the substrate support; wherein the disk-shaped body further includes a second chamfered edge configured to engage with an edge of a recess in the substrate support and guide the calibration disk from the first target position on the substrate support to a second target position, at which the calibration disk is centered on the substrate support.

16. The calibration disc as claimed in claim 15, wherein the chamfered edge has a first inlet and wherein the second chamfered edge has a second inlet smaller than the first inlet.

17. The calibration disc as claimed in claim 15, wherein the disc body and the three arms are parts of a solid sintered ceramic product that is usable at temperatures up to about 400°C without damaging the calibration disc.

18. The calibration disk as claimed in claim 15, wherein the calibration disk is configured to thermally expand at an operating temperature of the processing chamber, and wherein the calibration disk is configured to calibrate the processing chamber at the operating temperature.

19. The calibration disk as described in claim 15, wherein the chamfered edges of the calibration disk contain a slope of about 45 degrees.

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