METHODS, SYSTEMS, AND APPARATUS FOR MEASURING A GAP BETWEEN A SUPPORT SURFACE FOR A SUBSTRATE AND AN OPPOSING UPPER SURFACE OF A PROCESSING CHAMBER

Methods, systems, and apparatus for measuring a gap between a support surface for a substrate and an opposing upper surface of a processing chamber. The methods comprise: disposing a sensor substrate at a location spaced between the support surface and the upper surface, the sensor substrate comprising a body having a first side and a second side opposite the first side, the first side facing the support surface and the second side facing the upper surface, the first side having a first sensor and the second side having a second sensor; measuring, using the first sensor, a first distance between the first side and the support surface; measuring, using the second sensor, a second distance between the second side and the upper surface; and determining a gap between the support surface and the upper surface using the first distance and the second distance.

FIELD

Embodiments of the present disclosure generally relate to semiconductor manufacturing, and, more particularly, to methods, systems, and apparatus for measuring gaps in semiconductor manufacturing environments.

BACKGROUND

In semiconductor manufacturing, process uniformity over a substrate may be desirable to provide high yields. In substrate deposition processes, such as plasma processing, factors that can affect process uniformity include gap spacing and parallelism between the substrate and structures of the processing chamber facing the substrate, such as showerhead or sputtering target. Some currently available gap measurement tools sit on the substrate support while taking measurements for gap and parallelism.

Some measurement tools are limited in their environmental operating range and cannot operate at processing conditions so that some processing chambers are vented prior to introducing gap measurement tools into the processing chambers to perform measurements. Accordingly, equipment down-time for calibration is increased. Additionally, the measurements may not be accurate if the chamber is vented and cooled after calibration and then pumped back down after removal of the measurement tools.

Thus, the inventors propose methods, systems, and apparatus that provide accurate gap and parallelism measurements obtained at process conditions and without contacting the substrate support to improve calibration accuracy, as well as substrate processing throughput and yield.

SUMMARY

Methods, systems, and apparatus for measuring a gap between a support surface for a substrate and an opposing upper surface of a processing chamber, are provided herein. In some embodiments, a method for measuring a gap between a support surface for a substrate and an opposing upper surface of a processing chamber, the method comprising: disposing a sensor substrate at a location spaced between the support surface and the upper surface, the sensor substrate comprising a body having a first side and a second side opposite the first side, the first side facing the support surface and the second side facing the upper surface, the first side having a first sensor and the second side having a second sensor; measuring, using the first sensor, a first distance between the first side and the support surface; measuring, using the second sensor, a second distance between the second side and the upper surface; and determining a gap between the support surface and the upper surface using the first distance and the second distance.

In some embodiments, a method for calibrating a robot blade in a processing chamber having a support surface for a substrate, the method comprising: supporting a sensor substrate with the robot blade at a handoff position spaced from the support surface, the sensor substrate having an image capture device at a center of the sensor substrate; capturing an image that includes a portion of the support surface having an alignment feature, and a calibration feature of the image capture device; determining from the captured image whether there is a misalignment between the alignment feature and the calibration feature; and if there is a misalignment, calibrating the handoff position of the robot blade based on an amount of the misalignment.

In some embodiments, a sensor substrate, comprises: a body having a first side and a second side opposite the first side; a first sensor on the first side and configured for measuring distance; a second sensor on the second side and configured for measuring distance; and an image capture device located at a center of the sensor substrate.

DETAILED DESCRIPTION

Embodiments of a method, system, and apparatus are provided for measuring a gap between a support surface for a substrate and an opposing upper surface of a processing chamber. In the following description, numerous specific details are set forth in order to provide a thorough understanding of embodiments. However, one skilled in the art would appreciate that embodiments may be practiced without these specific details. In other instances, well-known aspects are not described in detail in order to not unnecessarily obscure embodiments. Furthermore, the various embodiments shown in the accompanying drawings are illustrative representations and are not necessarily drawn to scale.

The inventors have found that gap and parallelism measurements taken at conditions other than actual processing conditions, may lead to inaccurate calibrations and that measurement tool contact with the substrate support may cause damage to the substrate support (e.g., heaters) that may not be noticed until substrate processing commences. Accordingly, embodiments disclosed herein utilize a sensor substrate with sensors that can operate in processing chambers at process conditions and without contacting a substrate support. By using a sensor substrate in accordance with embodiments of the present disclosure, the sensor substrate can implement measurements at process conditions in a processing chamber without altering the temperature and pressure of a processing chamber before loading or removing the sensor substrate from the processing chamber. Therefore, embodiments disclosed herein allow for shorter calibration times, more accurate calibrations, and increased throughput capacity of the processing chamber. Also, by using a sensor substrate in accordance with embodiments of the present disclosure, by avoiding contact between the sensor substrate and the substrate support, damage to the substrate support due to calibration can be reduced or eliminated.

Referring now toFIG.1, a cross-sectional illustration of a processing tool100is shown in accordance with some embodiments. In some embodiments, and as shown inFIG.1, the processing tool100may comprise a processing chamber102(e.g., a PVD or CVD chamber). A vacuum pump (not shown) may be fluidically coupled to the processing chamber102to provide a less than atmospheric pressure within the processing chamber102during operation. In some embodiments, and as shown inFIG.1, the processing tool100may comprise a support surface104for supporting substrates in the processing chamber102. The support surface104may be an electrostatic chuck (ESC) or any other suitable surface for securing and supporting substrates. In some embodiments, the support surface104may include a heating element106for heating a substrate supported by the support surface104.

In some embodiments, and as shown inFIG.1, the processing chamber102may have an upper surface108that opposes the support surface104. In some embodiments, the upper surface108may include or be part of a showerhead (also referred to as a gas distribution plate). One or more process gases may be introduced into the processing chamber102through the showerhead. The showerhead may also function as an electrode in the processing tool100. In some embodiments, the upper surface108may include or be a part of a sputtering target.

While several particular components of the processing tool100are explicitly shown inFIG.1, any number of additional components common to processing tools in the semiconductor manufacturing field may also be included in the processing tool100, as those skilled in the art will recognize. In some embodiments, the processing tool100may be a plasma processing tool (e.g., a plasma etch tool, a physical vapor deposition (PVD) tool, a plasma enhanced chemical vapor deposition (PE-CVD) tool, a plasma enhanced atomic layer deposition (PE-ALD) tool, or the like). Embodiments may also include processing tools100that are not plasma-based tools (e.g., CVD, ALD, furnaces, etc.).

In some embodiments, and as shown inFIG.1, the distance or gap between the support surface104and the upper surface108may be measured with a sensor substrate110. In some embodiments, and as shown inFIG.1, the sensor substrate110may comprise a body112having a first side114that opposes the support surface104and having a second side116that opposes the upper surface108. In some embodiments, the sensor substrate110may have overall shape and dimensions similar to a semiconductor wafer or a substrate supported by the support surface104. In some embodiments, the sensor substrate may be a wafer or other common substrate form (glass panels or the like). In some embodiments where the sensor substrate110is a wafer or other common substrate form may be advantageous for allowing handling of the sensor substrate110using existing substrate handling equipment without modification.

In some embodiments and as shown inFIG.1, the sensor substrate110may have a first sensor124on the first side for measuring a first distance, such as a first gap G1, between the first side114and the support surface104. In some embodiments, and as shown inFIG.1, the sensor substrate110may have a second sensor126on the second side116for measuring a second distance, such as a second gap G2, between the second side116and the upper surface108. In some embodiments, at least one of the first sensor124or the second sensor126may be a capacitive sensor capable of measuring distances up to 600 mm while operating under substrate processing conditions. In some embodiments, at least one of the first sensor124or the second sensor126may be flush, recessed, embedded in, or extend from the body112.

In some embodiments, and as shown inFIG.1, the sensor substrate110may measure the first gap G1and the second gap G2while being positioned at a handoff position of a robot blade130that supports the sensor substrate110. In some embodiments, and as shown inFIG.4, when the sensor substrate110is supported by the robot blade130, the first sensors124are not covered by the robot blade130and have a line of sight to the support surface104. In the handoff position, the sensor substrate110is supported by the robot blade130and the sensor substrate110is at a location spaced between the upper surface108and the support surface104. Thus, in the handoff position, the sensor substrate110is located at a position spaced above the support surface104and spaced below the upper surface108. In some embodiments, in the handoff position, a majority of the sensor substrate110is located directly above the support surface104. In some embodiments, when disposed at the handoff position, the first sensor124may be located less than 600 mm from the support surface104and the second sensor126may be located less than 600 mm from the upper surface108.

Since a thickness T of the sensor substrate110is known, a total gap distance between the upper surface108and the support surface104may be accurately measured using the first gap G1, the second gap G2, and thickness T. Furthermore, in some embodiments, and as shown inFIG.1, where a plurality of first sensors124and a plurality of second sensors126are included with the sensor substrate110, a plurality of first gap G1readings and a plurality of second gap G2reading may be obtained across the sensor substrate110. By providing a plurality of gap readings across the sensor substrate110, a parallelism measurement between the upper surface108and the support surface104may be made in accordance with some embodiments.

In some embodiments, and as shown inFIGS.2and4, the sensor substrate110may include a plurality of first sensors124on the first side114and the first sensors124may be spaced equidistantly from a central axis A of the sensor substrate110. In some embodiments, and a shown inFIG.3, the sensor substrate110may include a plurality of second sensors126on the second side116and the second sensors126may be spaced equidistantly from the central axis A of the sensor substrate110. In some embodiments, and as shown inFIGS.1-4, each first sensor124may be located opposite (e.g., axially) a corresponding second sensor126.

In some embodiments, and as shown inFIGS.2and4, the sensor substrate110may include an image capture device202located at a center of the sensor substrate (centered with respect to axis A). In some embodiments, and as shown inFIGS.2and4, the image capture device202may be located on the first side114of the body112to face the support surface104. The image capture device202may be configured to capture images of at least a portion of the support surface104facing the image capture device202. In some embodiments, and as shown inFIGS.7A-7C, the image capture device202may be configured to view and capture an image of the entire support surface104. As discussed in further detail below, the portion of the support surface104may include an alignment feature, such as alignment feature702shown inFIGS.7A-7C, described in greater detail below.

In some embodiments, and as shown inFIG.2, the image capture device202may include a camera (e.g., a digital camera) having a lens204with a calibration feature206. In some embodiments, and as shown inFIG.2, the calibration feature206may be a circle centered on the lens204. In some embodiments, and as shown inFIG.2, the calibration feature206may include one or more concentric circles on the lens204. In some embodiments, where the image capture device202is a camera with lens204, images captured using the lens204may include at least one calibration feature206(two are shown inFIG.2), as well as the portion of the support surface104having an alignment feature.

In some embodiments, the image capture device202may include a projector212configured to project the calibration feature206onto a surface (e.g., the support surface104) opposite the image capture device202so that the calibration feature206may be included in images captured by the image capture device202. In some embodiments, the projector may include a light source (e.g., laser or LED) located behind the lens204to illuminate the calibration feature206. Light from the light source on the lens may display an image of the calibration feature206on the support surface104. The projector212may be configured and accurately positioned so that the projected image of the calibration feature206is centered with the lens204.

In some embodiments, and as shown inFIGS.2and4, the sensor substrate110may have a center ring210that is centered about axis A of the sensor substrate110and that can be aligned with a hole402of the robot blade130. The hole402provides the image capture device202an unobstructed view of the support surface104when the sensor substrate110is supported and positioned by the robot blade130at the handoff position.

In some embodiments, and as shown inFIG.1, the sensor substrate110may include a vibration sensor140for measuring vibration of the sensor substrate110. In some embodiments, the vibration sensor may be a MEMS sensor. In some embodiments, the vibration sensor may be an optical sensor. In some embodiments, vibration measurements may be taken to measure vibration caused by a robot (not shown) moving the robot blade130and the sensor substrate110. In some embodiments, vibration measurements at a certain time may be compared with previous vibration measurements for qualitative and/or quantitative comparison to determine an amount of wear on components (e.g., motors) of the robot to which the robot blade130is coupled. In some embodiments, vibrations exceeding a certain amount may indicate that repair or preventive maintenance of the robot is needed. In some embodiments, the sensor substrate110may be supported by lift pins (not shown) extending through the support surface104that are controlled by lift pin actuators (not shown). Vibration measurements obtained from the vibration sensor140while lift pin actuators are in operation may be compared with prior vibration measurements obtained for qualitative and/or quantitative comparison to determine an amount of wear on the lift pin actuators.

In some embodiments, and as shown inFIG.1, the sensor substrate110may include a control module150on or in the body112connected to the first sensor124and the second sensor126. The control module150may comprise circuitry for sensing a first distance (e.g., gap G1) between the first side114of the body112and a first surface (e.g., support surface104) external to the sensor substrate110opposing the first side114using the first sensor124and comprise circuitry for sensing a second distance (e.g., gap G2) between the second side116of the body112and a second surface (e.g., the upper surface108) external to the sensor substrate110opposing the second side116using the second sensor126. In some embodiments, the control module150may be connected to the image capture device202and may include circuitry for acquiring images of the first surface (e.g., support surface104). In some embodiments, the control module150may be connected to the vibration sensor140and may include circuitry for acquiring vibration measurements of the sensor substrate110.

In some embodiments, the control module150may include one or more of a processor, a memory, and a wireless communication module (e.g., Bluetooth, WiFi, or the like). The inclusion of a wireless communication module may allow for data (e.g., distance measurement data, image data, vibration data) to be transferred to an external device that may control the positioning of the support surface104relative to the upper surface108and/or to an external device that may control the positioning of the robot blade130.

In some embodiments, the control module150may include a power source (e.g., battery) for powering any of the circuitry, processor, memory, or wireless communication module of the control module150and at least one of the first sensor124, second sensor126, image capture device202, or vibration sensor140.

In some embodiments, the sensor substrate110may have substantially the same form-factor as substrates that are processed in the processing tool100. For example, the sensor substrate110may have a diameter that is 300 mm. A sensor substrate110that has a form-factor that is substantially similar to the form-factor of the substrates may facilitate the calibration of the processing tool100without venting the processing chamber. For example, in some embodiments, the robot blade130and the sensor substrate110may fit through load locks (not shown) of the processing tool100to avoid vacuum breaks.

FIG.5shows a method500for measuring a gap between a support surface for a substrate and an opposing upper surface of a processing chamber in accordance with some embodiments of the present disclosure. At block502, the method includes disposing a sensor substrate (e.g., sensor substrate110) at a location spaced between a support surface (e.g., support surface104) and an upper surface (e.g., upper surface108) of a processing chamber (e.g., processing chamber102). In some embodiments, and as shown inFIG.1, upon disposing the sensor substrate110(e.g., at a handoff position of the robot blade130), the first side114faces the support surface104and the second side116faces the upper surface108.

At block504, the method500may include measuring, using the first sensor (e.g., first sensor124), a first distance (e.g., first gap G1) between the first side (e.g., first side114) and the support surface (e.g., support surface104). At block506, the method500may include measuring, using the second sensor (e.g., second sensor126), a second distance (e.g., second gap G2) between the second side (e.g., second side116) and the upper surface (e.g., upper surface108). At block508, the method500may include determining a gap between the support surface (e.g., support surface104) and the upper surface (e.g., upper surface108) using the first distance (e.g., first gap G1) and the second distance (e.g., second gap G2). For example, as noted above, the thickness T of the body112may be known so that a total gap between the upper surface and the support surface may be obtained from the first gap G1, the second gap G2, and the thickness T.

In some embodiments, the method500may be performed while the sensor substrate (e.g., sensor substrate110) is disposed in the processing chamber (e.g., processing chamber102) and while the processing chamber is operating under substrate processing conditions of temperature and pressure. In some embodiments, the operating process temperature in the processing chamber102may be −20° C. to 450° C. for 15 s. In some embodiments, the operating process temperature in the processing chamber may be −20° C. to 650° C. In some embodiments, at least one of measuring the first distance (e.g., first gap G1) or measuring the second distance (e.g., second gap G2) is performed while the support surface is at a temperature of 100° C. or greater. In some embodiments, at least one of measuring the first distance (e.g., first gap G1) or measuring the second distance (e.g., second gap G2) is performed while the support surface is at a temperature of 200° C. or greater. In some embodiments, at least one of measuring the first distance (e.g., first gap G1) or measuring the second distance (e.g., second gap G2) is performed while the support surface is at a temperature of 300° C. or greater. In some embodiments, at least one of measuring the first distance (e.g., first gap G1) or measuring the second distance (e.g., second gap G2) is performed while the support surface is at a temperature of 400° C. or greater. In some embodiments, at least one of measuring the first distance (e.g., first gap G1) or measuring the second distance (e.g., second gap G2) is performed while the support surface is at a temperature of 500° C. or greater. In some embodiments, at least one of measuring the first distance (e.g., first gap G1) or measuring the second distance (e.g., second gap G2) is performed while the support surface is at a temperature of 600° C. or greater. In some embodiments, the operating process pressure in the processing chamber102may be ATM to 5E-9 Torr.

In some embodiments, at block510, the method500may include measuring, using a plurality of first sensors (e.g., first sensors124), a first plurality of distances between the first side (e.g., first side114) and the support surface (e.g., support surface104); measuring, using a plurality of second sensors (e.g., second sensors126), a second plurality of distances between the second side (e.g., second side116) and the upper surface (e.g., upper surface108); and determining a parallelism measurement between the support surface and the upper surface based on the first plurality of distances and the second plurality of distances. In some embodiments, the first plurality of distances and the second plurality of distances may be measured substantially at the same time.

In some embodiments, and as shown inFIGS.2and3, each of the first plurality of distances (e.g., gap G1) may be measured from locations on the first side114that are equidistantly spaced from a center of the sensor substrate110, and each of the second plurality of distances (e.g., gap G2) may be measured from locations on the second side116that are equidistantly spaced from the center of the sensor substrate110.

In some embodiments, at block512, the method500may include adjusting the support surface (e.g., support surface104) parallel to the upper surface (e.g., upper surface108) based on the parallelism measurement.

In some embodiments, at block514, the method500may include removing the sensor substrate (e.g., sensor substrate110) from the processing chamber (e.g., processing chamber102). In some embodiments, a wafer handling robot may be used to control the robot blade130to remove the sensor substrate110from the processing chamber102. In some embodiments, the sensor substrate110may be removed without venting the processing chamber or otherwise altering the process conditions (e.g., temperature and pressure). Thus, the processing chamber102may be calibrated (i.e., adjusted to provide a desired gap and parallelism between the upper surface and the support surface) without altering the process conditions in order to begin processing substrates.

FIG.6shows a method600for calibrating a robot blade in a processing chamber having a support surface for a substrate, in accordance with embodiments of the present disclosure. At block602, the method600may include supporting a sensor substrate (e.g., sensor substrate110) with a robot blade (e.g., robot blade130) at a handoff position spaced from a support surface (e.g., support surface104). In some embodiments, and as shown inFIGS.2and4, the sensor substrate110may have an image capture device202at a center of the sensor substrate110. In some embodiments, at block604, the method600may include capturing an image that includes a portion of the support surface having an alignment feature, and a calibration feature (e.g., calibration feature206) of the image capture device. In some embodiments, and as shown inFIGS.7A-7C, the entire support surface104may be captured by the image capturing device. In some embodiments, and as shown inFIGS.7A-7C, the support surface104has an alignment feature702shown as a center hole of the support surface104and the calibration feature206may be shown in the captured image with the alignment feature702.

In some embodiments, and at block606, the method600may include determining from the captured image whether there is a misalignment between the alignment feature and the calibration feature. For example, in the captured image shown inFIG.7A, the alignment feature702is a central hole of the support surface104and the alignment features702is centered within the calibration feature206, which is shown as a circle surrounding the central hole. Thus, a determination may be made that the alignment feature702and the calibration feature206inFIG.7Aare aligned. In the captured image shown inFIG.7B, the alignment feature702is not centered with the calibration feature206and, thus, a determination may be made that there is a misalignment between the alignment feature702and the calibration feature206inFIG.7B.

In some embodiments, and at block608, if there is a misalignment between the alignment feature and the calibration feature, the method600may include calibrating the handoff position of the robot blade (e.g., robot blade130) based on an amount of the misalignment. In some embodiments, the method600may include measuring the amount of the misalignment between the alignment feature and the calibration feature as an offset distance between the alignment feature and the center of the calibration feature. In some embodiments, using the captured image, distance measurements along two orthogonal axes may be made between the center of the alignment feature and the center of the calibration feature and the orthogonal distance measurements may be used to adjust the robot blade in the handoff position.

In some embodiments, at block610, the method600may include determining whether the robot blade (e.g., robot blade130) is parallel with the support surface (e.g., support surface104) using the captured image by measuring an amount of distortion of the calibration feature (e.g., calibration feature206). For example,FIG.7Cshows the circular calibration feature206inFIGS.7A and7Bdistorted as an ellipse, indicating that the robot blade130is not parallel to the support surface104(e.g., the robot blade130has drooped). In some embodiments, the amount of distortion may be determined by measuring a dimensional change of the calibration feature206. In some embodiments, at least one of the major axis or minor axis of the ellipse shown inFIG.7Cmay be compared to the dimension (e.g. diameter) of the undistorted calibration feature206to determine an angle of droop of the robot blade130. In some embodiments, a lookup table or mathematical formula may be used to correlate dimensional changes of the calibration feature206to the angle between the robot blade130and the support surface104.

In some embodiments, and as shown inFIGS.8A and8B, the portion of the support surface104that is captured by the image capture device202may include a plurality of alignment features, such as lift pins or lift pin holes. In some embodiments, a plurality of gas (e.g., backside cooling) holes may be used as alignment features. InFIG.8A, the calibration feature206is shown as a circle and the alignment features802include a plurality of lift pin holes that are aligned with the circle, indicating that the calibration feature206and the alignment features802are aligned. InFIG.8B, the calibration feature206is shown as a circle that is not aligned with the three lift pin holes, indicating that the calibration feature206is not aligned with the alignment features802.

Referring now toFIG.9, a block diagram of an exemplary computer system660of a processing tool is illustrated in accordance with an embodiment. In an embodiment, computer system960is coupled to and controls processing in the processing tool and/or calibration measurements of the processing tool with a sensor substrate. Computer system960may be connected (e.g., networked) to other machines in a network961(e.g., a Local Area Network (LAN), an intranet, an extranet, or the Internet). Computer system960may operate in the capacity of a server or a client machine in a client-server network environment, or as a peer machine in a peer-to-peer (or distributed) network environment. Computer system960may be a personal computer (PC), a tablet PC, a set-top box (STB), a Personal Digital Assistant (PDA), a cellular telephone, a web appliance, a server, a network router, switch or bridge, or any machine capable of executing a set of instructions (sequential or otherwise) that specify actions to be taken by that machine. Further, while only a single machine is illustrated for computer system960, the term “machine” shall also be taken 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 methodologies described herein.

Computer system960may include a computer program product, or software922, having a non-transitory machine-readable medium having stored thereon instructions, which may be used to program computer system960(or other electronic devices) to perform a process according to embodiments. A machine-readable medium includes any mechanism for storing or transmitting information in a form readable by a machine (e.g., a computer). For example, a machine-readable (e.g., computer-readable) medium includes a machine (e.g., a computer) readable storage medium (e.g., read only memory (“ROM”), random access memory (“RAM”), magnetic disk storage media, optical storage media, flash memory devices, etc.), a machine (e.g., computer) readable transmission medium (electrical, optical, acoustical or other form of propagated signals (e.g., infrared signals, digital signals, etc.)), etc.

In an embodiment, computer system960includes a system processor902, a main memory904(e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM) such as synchronous DRAM (SDRAM) or Rambus DRAM (RDRAM), etc.), a static memory906(e.g., flash memory, static random access memory (SRAM), etc.), and a secondary memory918(e.g., a data storage device), which communicate with each other via a bus930.

System processor902represents one or more general-purpose processing devices such as a microsystem processor, central processing unit, or the like. More particularly, the system processor may be a complex instruction set computing (CISC) microsystem processor, reduced instruction set computing (RISC) microsystem processor, very long instruction word (VLIW) microsystem processor, a system processor implementing other instruction sets, or system processors implementing a combination of instruction sets. System processor902may 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 system processor (DSP), network system processor, or the like. System processor902is configured to execute the processing logic926for performing the operations described herein.

The computer system960may further include a system network interface device908for communicating with other devices or machines. The computer system960may also include a video display unit910(e.g., a liquid crystal display (LCD), a light emitting diode display (LED), or a cathode ray tube (CRT)), an alphanumeric input device912(e.g., a keyboard), a cursor control device914(e.g., a mouse), and a signal generation device916(e.g., a speaker).

The secondary memory918may include a machine-accessible storage medium931(or more specifically a computer-readable storage medium) on which is stored one or more sets of instructions (e.g., software922) embodying any one or more of the methodologies or functions described herein. The software922may also reside, completely or at least partially, within the main memory904and/or within the system processor902during execution thereof by the computer system960, the main memory904and the system processor902also constituting machine-readable storage media. The software922may further be transmitted or received over a network961via the system network interface device908.

Embodiments described herein provide for in-situ gap measurements and parallelism measurements between a support surface and an opposing upper surface in a processing chamber of a processing tool. By providing a sensor substrate that can take measurements at substrate process conditions, accuracy of calibrations can be improved and downtime of the processing tool due to calibration can be reduced, thereby increasing throughput. Moreover, as the accuracy of calibrations is improved, the uniformity of substrate processing can also be improved, further reducing rework and improving yield.