Detection and analysis of substrate support and pre-heat ring in a process chamber via imaging

An apparatus, method, and system for identifying and obtaining information related to a substrate support and/or a pre-heat ring in a process chamber via imaging and image processing. In an embodiment, a substrate support is provided. The substrate support generally includes a top surface configured to receive a substrate in a process chamber and a marking feature disposed on the top surface of the substrate support, the marking feature configured to be detectable by an imaging apparatus coupled to the process chamber to provide information related to the substrate support via imaging when the substrate support is disposed within the process chamber.

FIELD

The present disclosure relates to semiconductor manufacturing and processing. More particularly, the disclosure relates to an apparatus, method, and system for fabricating devices on a semiconductor substrate. Specifically, embodiments of the present disclosure provide an apparatus, method, and system for identifying and analyzing a substrate support and/or a pre-heat ring in a process chamber via imaging.

BACKGROUND

Trends toward smaller critical dimensions in semiconductor processing have caused an exponential increase in the precision with which fabrication processes must be performed by the semiconductor device manufacturer. Semiconductor based integrated circuits are typically manufactured through the formation of a set of layers on a substrate containing many integrated circuit areas which will later be separated into individual dies. Very thin layers of material are deposited one on top of the other in patterns to form integrated circuit components.

In a semiconductor device fabrication process, such as CVD, epitaxy, or other thermal processing, substrates are often processed within chambers or other processing apparatuses. In order to process a substrate within the chamber, the substrate may be firmly attached to a substrate support (e.g. susceptor) within the chamber during processing to mitigate movement of the substrate. A variety of substrate supports with different designs and corresponding pre-heat rings for use therewith have been developed and are used to accommodate for a variety of substrates and process chambers. For example, substrate supports are designed with varying pocket sizes and surface features that may each require specific set up and substrate handling protocols to properly use the substrate support. For example, a substrate support designed with a tighter pocket provides less clearance for substrate placement and would require more precise substrate handling protocols when loading the substrate on the substrate support. Improper set up and/or handling procedures in relation to the specific substrate support used and/or the corresponding pre-heat ring may cause the substrate support to be improperly installed and/or misaligned when in use which can adversely affect the fabrication process or the quality/performance of the component being produced.

With conventional substrate supports and pre-heat rings in process chambers, visualization systems implemented in process chambers for viewing processing of substrates are currently unable to identify the substrate support or the pre-heat ring installed in a process chamber through imaging the substrate support and pre-heat ring. For example, to identify conventional substrate supports installed in a process chamber, the substrate support is removed from the process chamber by users to manually view the identification information on the back side of the substrate support.

Depending on the design and use of the substrate support and the pre-heat ring, the substrate support and pre-heat ring will both have a limited service life in which the parts can be effectively and reliable used in process chambers. For example, degradation will eventually affect the performance of the substrate support, such as the substrate no longer being firmly adhered to the substrate support. In processing, this may cause the substrate to move—which may cause substrate misalignment. If the substrate becomes misaligned, uniformity in thickness and/or film properties may be adversely impacted.

Therefore, a need exists for an improved apparatuses, methods and systems for identifying and imaging substrate supports and pre-heat rings used in a process chamber.

SUMMARY

The present disclosure provides an apparatus, method, and system for identifying and analyzing a substrate support in a process chamber via imaging. In some embodiments, a substrate support is provided. The substrate support includes a top surface configured to receive a substrate in a process chamber and a marking feature disposed on the top surface of the substrate support. The marking feature is configured to be detectable by an imaging apparatus coupled to the process chamber to provide information related to the substrate support via imaging when the substrate support is disposed within the process chamber.

In another embodiment, a substrate support is provided. The substrate support includes a top surface configured to receive a substrate in a process chamber and a marking feature disposed on the top surface of the substrate support. The marking feature includes a height extending from the top surface of the substrate support and an outer surface containing silicon carbide (SiC). The marking feature is configured to be detectable by an imaging apparatus coupled to the process chamber when the substrate support is disposed within the process chamber.

In yet another embodiment, a processing system configured to analyze a substrate support disposed in a process chamber is provided. The processing system includes a process chamber having a process volume and an imaging apparatus coupled to the process chamber. The imaging apparatus includes a view field and is coupled to a controller having a processor and a memory. The memory includes a software program configured to perform an operation for imaging and obtaining information related to a substrate support disposed in the processing volume of the process chamber when the substrate support is in the view field of the imaging apparatus. The substrate support includes a top surface configured to receive a substrate in the process chamber and a marking feature disposed on the top surface of the substrate support. The marking feature is configured to be detectable by the imaging apparatus to provide information related to the substrate support via imaging when the substrate support is disposed within the process chamber.

DETAILED DESCRIPTION

Embodiments described herein generally relate to an apparatus and method for identifying a substrate support and/or a pre-heat ring in a process chamber and obtaining information related to the substrate support, the pre-heat ring (if present) and their use in the process chamber thereof. In one example, methods and apparatus for identifying the substrate support generally include disposing a marking feature on a top surface of the substrate support and imaging the marking feature when the substrate support is disposed inside the process chamber to identify and determine the specific model (or design) of the substrate support in the process chamber. The same is also applicable to identify the pre-heat ring in the processing chamber by disposing the marking feature on a top surface of the pre-heat ring. Each marking feature to be disposed on a substrate support or a pre-heat ring corresponds with a specific model (or design) of an available substrate support or pre-heat ring, respectively. When the specific marking feature on the substrate support and pre-heat ring is imaged, the marking feature is analyzed and may then be used to identify the model of the respective substrate support or pre-heat ring the imaged marking feature is disposed on.

In another example, methods and apparatus for monitoring and analyzing a substrate support and/or a pre-heat ring used in a process chamber generally include disposing a marking feature on a top surface of the substrate support and/or the pre-heat ring, imaging the marking feature when the substrate support and/or the pre-heat ring is inside the process chamber, and analyzing the marking feature to obtain information related to the substrate support and/or the pre-heat ring the imaged marking feature is disposed on. Examples of information that may be obtained from the imaging of the marking feature on the substrate support or the pre-heat ring include information related to a reference measurement for direct scaling at the substrate support and pre-heat ring level of imaging obtained of the substrate support or the pre-heat ring in the process chamber, a reference point for detection and determination of rotation angles by the substrate support or the pre-heat ring in the process chamber, a reference point for detection and tracing of the installation position of the substrate support or the pre-heat ring in the process chamber, and/or an indication of when the substrate support or the pre-heat ring is likely to be near the end of its service life.

Typically, processing systems have a centralized transfer chamber mounted on a monolith platform. The transfer chamber is the center of activity for the movement of substrates being processed in the system. One or more process chambers are mounted to the transfer chamber at slit valves through which substrates are passed by a substrate handler, or robot. Access to the transfer chamber from the clean ambient environment is typically through one or more load lock chambers attached at other slit valves. The load lock chambers may open to a very clean room, referred to as the white area, or to an optional substrate handling chamber, typically referred to as a mini-environment.

FIG.1shows a schematic sectional view of a process chamber100having a substrate support assembly and a visualization apparatus, in accordance with certain aspects of the present disclosure. The process chamber100may be configured to perform epitaxial deposition processes. The process chamber100may be used to process one or more substrates, including the deposition of a material on an upper surface of a substrate108. The process chamber100may include an array of radiant heating lamps102for heating, among other components, a back side104of a substrate support106(e.g., which may be a susceptor) disposed within the process chamber100. In some embodiments, the array of radiant heating lamps may be disposed over the upper dome128. The substrate support106may be a disk-like substrate support106as shown, or may be a ring-like substrate support107with no central opening, which supports the substrate from the edge of the substrate to facilitate exposure of the substrate to the thermal radiation of the lamps102.

The substrate support106is located within the process chamber100between an upper dome128and a lower dome114. The upper dome128, the lower dome114and a base ring136that is disposed between the upper dome128and lower dome114generally define an internal region of the process chamber100. The substrate108(not to scale) can be brought into the process chamber100and positioned onto the substrate support106through a loading port103.

The substrate support106is shown in an elevated processing position, but may be vertically traversed by an actuator (not shown) to a loading position below the processing position to allow lift pins105to contact the lower dome114, passing through holes in the substrate support106and the central shaft132, and raise the substrate108from the substrate support106. A robot (not shown) may then enter the process chamber100to engage and remove the substrate108therefrom though the loading port103. The substrate support106then may be actuated up to the processing position to place the substrate108, with its device side116facing up, on a top surface110of the substrate support106.

The substrate support106, while located in the processing position, divides the internal volume of the process chamber100into a process gas region156that is above the substrate, and a purge gas region158below the substrate support106. The substrate support106is rotated during processing by a central shaft132to minimize the effect of thermal and process gas flow spatial anomalies within the process chamber100and thus facilitate uniform processing of the substrate108. The substrate support106is supported by the central shaft132, which moves the substrate108in an up and down direction134during loading and unloading, and in some instances, processing of the substrate108. The substrate support106may be formed from silicon carbide or graphite coated with silicon carbide to absorb radiant energy from the lamps102and conduct the radiant energy to the substrate108.

In general, the central window portion of the upper dome128and the bottom of the lower dome114are formed from an optically transparent material such as quartz. “Optically transparent” here means generally transmissive to radiation, but not necessarily 100% transmissive. As will be discussed in more detail below with respect toFIG.1, the thickness and the degree of curvature of the upper dome128may be configured in accordance with the present invention to provide a flatter geometry for uniform flow uniformity in the process chamber.

One or more lamps, such as an array of lamps102, can be disposed adjacent to and beneath the lower dome114in a specified manner around the central shaft132to independently control the temperature at various regions of the substrate108as the process gas passes over, thereby facilitating the deposition of a material onto the upper surface of the substrate108. While not discussed here in detail, the deposited material may include gallium arsenide, gallium nitride, or aluminum gallium nitride, among other materials.

The lamps102may be configured to include bulbs141and be configured to heat the substrate108to a temperature within a range of about 200 degrees Celsius to about 1600 degrees Celsius. Each lamp102is coupled to a power distribution board (not shown) through which power is supplied to each lamp102. The lamps102are positioned within a lamphead145which may be cooled during or after processing by, for example, a cooling fluid introduced into channels149located between the lamps102. The lamphead145conductively and radiatively cools the lower dome114due in part to the close proximity of the lamphead145to the lower dome114. The lamphead145may also cool the lamp walls and walls of the reflectors (not shown) around the lamps. Alternatively, the lower dome114may be cooled by a convective approach. Depending upon the application, the lampheads145may or may not be in contact with the lower dome114.

A circular shield167may be optionally disposed around the substrate support106and surrounded by a liner assembly163. The shield167prevents or minimizes leakage of heat/light noise from the lamps102to the device side116of the substrate108while providing a pre-heat zone for the process gases. The shield167may be made from CVD SiC, sintered graphite coated with SiC, grown SiC, opaque quartz, coated quartz, or any similar, suitable material that is resistant to chemical breakdown by process and purging gases.

The liner assembly163is sized to be nested within or surrounded by an inner circumference of the base ring136. The liner assembly163shields the processing volume (i.e., the process gas region156and purge gas region158) from metallic walls of the process chamber100. The metallic walls may react with precursors and cause contamination in the processing volume. While the liner assembly163is shown as a single body, the liner assembly163may include one or more liners with different configurations.

As a result of backside heating of the substrate108from the substrate support106, the use of an optical pyrometer118for temperature measurements/control on the substrate support can be performed. This temperature measurement by the optical pyrometer118may also be done on substrate device side116having an unknown emissivity since heating the substrate top surface110in this manner is emissivity independent. As a result, the optical pyrometer118can only sense radiation from the hot substrate108that conducts from the substrate support106, with minimal background radiation from the lamps102directly reaching the optical pyrometer118.

A reflector122may be optionally placed outside the upper dome128to reflect infrared light that is radiating off the substrate108back onto the substrate108. The reflector122may be secured to the upper dome128using a clamp ring130. The reflector122can be made of a metal such as aluminum or stainless steel. The efficiency of the reflection can be improved by coating a reflector area with a highly reflective coating such as with gold. The reflector122can have one or more conduits126connected to a cooling source (not shown). The conduit126connects to a passage (not shown) formed on a side of the reflector122. The passage is configured to carry a flow of a fluid such as water and may run horizontally along the side of the reflector122in any desired pattern covering a portion or entire surface of the reflector122for cooling the reflector122.

Process gas supplied from a process gas supply source172is introduced into the process gas region156through a process gas inlet174formed in the sidewall of the base ring136. The process gas inlet174is configured to direct the process gas in a generally radially inward direction. During the film formation process, the substrate support106may be located in the processing position, which is adjacent to and at about the same elevation as the process gas inlet174, allowing the process gas to flow up and round along flow path173across the upper surface of the substrate108in a laminar flow fashion. The process gas exits the process gas region156(along flow path175) through a gas outlet178located on the side of the process chamber100opposite the process gas inlet174. Removal of the process gas through the gas outlet178may be facilitated by a vacuum pump180coupled thereto. As the process gas inlet174and the gas outlet178are aligned to each other and disposed approximately at the same elevation, it is believed that such a parallel arrangement, when combing with a flatter upper dome128(as will be discussed in detail below), will enable a generally planar, uniform gas flow across the substrate108. Further radial uniformity may be provided by the rotation of the substrate108through the substrate support106.

FIGS.2A and2Bshows an example of the substrate support106that may be used in the process chamber ofFIG.1, according to certain embodiment of the present disclosure. The substrate support106includes a pocket201formed on a top surface202of the substrate support106. The pocket201is defined by an annular-shaped edge204which is further bound by a rim206. The pocket201includes a side wall208and a substrate receiving surface210for holding the substrate108. For a given substrate108, the substrate receiving surface210of the pocket201generally has a diameter only slightly larger than that of the substrate108. When in use, the substrate108is centered in the pocket201on the substrate receiving surface210and a gap is maintained between the edge of the substrate108and the side wall208of the pocket201.

As discussed above, methods and apparatus are provided herein for using a marking feature disposed on the substrate support to identify a model of the imaged substrate support (e.g., susceptor) disposed in a process chamber and/or obtaining information related to the substrate support and its use in the process chamber thereof. As such, a visualization system including an imaging apparatus (e.g., such as a camera200shown inFIG.1), either inside a process chamber (e.g., such as process chamber100) or outside the chamber but with a view through an aperture in the chamber, can be used to image the marking feature disposed on the substrate support when the substrate support is disposed within the chamber.

As shown inFIG.1, the process chamber100may include the camera200to view the substrate108, the substrate support106, and/or a pre-heat ring coupled to the substrate support106(not shown) in process chamber100during processing. The camera200may be positioned above the top of the process chamber100, and a collection device, for example a light pipe, for the camera may be disposed through the top of the process chamber100into the process gas region156. Alternately, the camera200may be positioned inside the process chamber100. For example, the camera200may be disposed in an opening186in the upper dome128between the upper dome128and the reflector122. The camera200, or a collection device for the camera, may be disposed through a portal for connecting the conduit126to the process chamber100, or alternatively, the camera200may be coupled to the chamber using a chassis. The camera200may be capable of operating in a vacuum or at atmospheric pressure. The camera200may be in the process chamber100to take an image of the substrate108, an edge ring, a mask, and/or the substrate support106. The position of the camera200relative to the upper dome128and the substrate support106, and the optical characteristics of the camera200may be determined to ensure a field of view that includes the regions of interest on the substrate support106.

The camera200can be electrically coupled to a controller190that controls operations (e.g., on/off, focusing, image-taking, and the like) of the camera200. The controller190also includes a central processing unit (CPU)192, a memory194, and a support circuit196. The CPU192may be one of any form of a general purpose computer processor that can be used in an industrial setting. The support circuit196is conventionally coupled to the CPU192and may comprise cache, clock circuits, input/output subsystems, power supplies, and the like. The software routines, when executed by the CPU192, transform the CPU192into a specific purpose computer (controller)191. The software routines may also be stored and/or executed by a second controller (not shown) that is located remotely from the process chamber100.

Memory194may store information for processing and retrieval during operation of CPU192. Memory194may store program instructions and/or data associated with the various marking features used and corresponding substrate support models, as described in accordance with one or more aspects of this disclosure. CPU192may execute instructions and one or more storage devices for memory194may store instructions and/or data of one or more software routines. The combination of CPU192and memory194may retrieve, store, and/or execute the instructions and/or data of one or more applications or software to be executed by the controller190. The controller190may download a program stored in the memory194through an input/output (I/O) device (not shown) and carry out imaging of the substrate support106and/or the coupled pre-heat ring by controlling the camera200in accordance with the program.

It should be noted that the camera200is only one example of an apparatus that can be used for imaging and that any other types of imaging apparatus can be used as a positioning detection apparatus. In embodiments, more than one camera can be used to capture images of the substrate support106. In embodiments, the camera200is an image capturing device which may include a high efficiency, low voltage complementary metal oxide semiconductor (CMOS) sensor, and as such, may function as a single chip video camera. The CMOS sensor may be of the VGA type. The camera200may include a lens, such as a wide angle lens or a plano-convex type lens having an appropriate focal length to provide sufficient visual clarity within the desired range of operation of the camera200. It will be apparent to those skilled in the art that different lenses (e.g., telescoping or rotational prism lenses) may be used for different applications. It will also be appreciated that other types of cameras or optical sensors may be employed, including, but not limited to cameras of the SVGA, XGA, MEGA pixel type, or other image capturing devices. If desired, multiple image capturing devices of differing types of resolution can be employed in conjunction with lenses of varying types and focal lengths. The camera or sensor could be of a static (still) or dynamic (video) type and could be of the charged coupled device (CCD) type. In addition, the camera could be used to output a video signal to any standard TV format.

In an embodiment, when imaging the substrate support106, the camera200may be used to image portions of the substrate support106within a view field193of the camera200(as shown inFIG.3A). For in situ imaging and analysis of the substrate support106in the process chamber100, the regions of interest of the substrate support106in which the marking feature may be disposed on include portions of the substrate support106where the top surface202of the substrate support106remain unoccupied when the substrate support106is loaded with the substrate108, as well as being within the field of view of the camera200.

In another embodiment, which can be combined with other embodiments described herein, the substrate support106may be coupled to a pre-heat ring207in a process chamber with the pre-heat ring207disposed around the periphery of the substrate support106when the substrate support106is in a processing position. The camera200may be used to image portions of the substrate support106and/or the pre-heat ring207coupled to the substrate support106within a view field193of the camera200(as shown inFIG.3B) to identify and analyze the substrate support106and/or the pre-heat ring207coupled thereto. For in situ imaging and analysis of the substrate support106and/or the pre-heat ring207in the process chamber, the regions of interest of the substrate support and the pre-heat ring207in which the marking feature may be disposed on include a top surface209of the pre-heat ring207and portions of the substrate support106where the top surface202of the substrate support106remain unoccupied when the substrate support106is loaded with the substrate108, as well as being within the field of view of the camera200.

FIG.3Cis an example image300from camera200positioned to capture images of the pre-heat ring207, the substrate support106, and the substrate108disposed in a process chamber. The image300includes regions of interest identified in which the marking feature may be disposed on, according to certain aspects of the present disclosure. As shown inFIG.3C, the marking feature may be disposed in a first region of interest212on the edge204of the substrate support106, a second region of interest214on the rim206of the substrate support106, and/or a third region of interest216on the pre-heat ring207. Since the substrate108would be loaded in the pocket201when the substrate support106is in use in the process chamber, marking features disposed on the pocket201would likely be covered by the substrate108and therefore not visible to the camera200. Moreover, depending on how the marking feature is formed, the marking feature may affect the processing of the substrate108if disposed in the pocket201. As such, regions of interest identified on the substrate support106include only the surface of the substrate support106on the edge204and rim206which are open when the substrate support106is in use. And, as shown inFIG.3C, marking features disposed in the first and/or second regions of interest212,214of the substrate support106, as well as the third region of interest216on the pre-heat ring207, are all capable of being imaged by the camera200when the substrate support106and pre-heat ring207are disposed within in the process chamber.

In some embodiments, depending on the shape, size, and positioning of the marking feature on the substrate support106and/or the pre-heat ring207, different numbers of regions may be imaged at different locations. In some embodiments, the shape of the imaged regions may vary. For example, an imaged region may be rectangular, circular, or other shape.

FIG.4Ashows a top view of an embodiment of the substrate support106having an example of a marking feature402disposed in the second region of interest214on the rim206of the substrate support106, according to certain embodiments herein. Although some examples are described herein as applying the marking feature402to the substrate support106, aspects and embodiments of the present disclosure described herein with respect to the marking feature402and the substrate support106may be similarly applicable to applying the marking feature402to the pre-heat ring207(if present in the process chamber).

When the substrate support106is disposed in the process chamber100, the substrate support106may be rotated about the central shaft132such that snap shots of the marking feature402on the substrate support106may be obtained by the camera200when the marking feature402is rotated within the view field193of the camera200. In an embodiment, which may be combined with other embodiments herein, the marking feature402may be of any type of designation capable of being disposed or formed on the top surface202of the substrate support106and detected by the camera200for analysis. In an embodiment, which may be combined with other embodiments discussed herein, the marking feature402may be a surface feature formed on the substrate support106. In another embodiment, the marking feature402may be a surface feature etched into the surface of the substrate support106. In certain embodiments, the designations for the marking feature402may include any number, letter, symbol, shape or pattern, including without limitation, a barcode, a numeric code, an alphanumeric code, a QR code, custom shapes, pattern of shapes, pattern of symbols, series of characters, special characters, and the like.

As mentioned above, each marking feature402to be disposed on the substrate support106and the pre-heat ring207may correspond with a specific model (or design) of a plurality of different substrate supports and pre-heat rings. Data associated with each of the marking features402used to identify each of the plurality of corresponding substrate support models may be stored in the memory194for search and retrieval by the controller190. After the specific marking feature402on the substrate support106is imaged, the marking feature402is analyzed and may be used to identify the model of the corresponding substrate support or pre-heat ring the imaged marking feature402is disposed on.

FIG.4Bshows a cross-sectional view of the substrate support106ofFIG.4Aalong section line4B-4B. In certain embodiments, the marking feature402may extend from the top surface202of the substrate support106and be disposed on the first region of interest212and/or the second region of interest214. The marking feature402may be sized and formed with a thickness sufficient for the marking feature402to be detected and imaged by the camera200from the surrounding top surface of the substrate support106. Alternatively, the marking feature402may be disposed on the substrate support106and formed with a surface roughness different from the surface roughness of the top surface202of the substrate support106such that the camera200is able to distinguish and detect the marking feature402for analysis.

The marking feature402may be formed from a material compatible with the processing environment, such as such as silicon carbide (SiC), or graphite coated with SiC. The marking features402may be formed on the substrate support106in any suitable fashion, such as being cast in the substrate support106, embossed into the substrate support106, machined into the substrate support106, deposited on the substrate support106, or by roughening or treating the top surface202of the substrate support106. For example, the features402may be conformally deposited on the top surface202of the substrate support106using a mask by a physical vapor deposition (PVD) process or other similar conformal deposition process. The conformal deposition of the marking features402enables the marking features402to retain a surface roughness similar to the surface roughness of remaining portions of the top surface202. By matching the surface roughness of the rest of the top surface202and the surface roughness of the marking features402, as described further below, the marking features402may be utilized to monitor the use of the substrate support106and act as an indicator of when the substrate support106likely to be near the end of its service life.

The imaging and analysis of the marking feature402on the substrate support106by the camera200in the process chamber100may be utilized to identify the specific design and model of the substrate support106loaded in the process chamber100without the need for removing the substrate support106from the process chamber100.

Since substrate supports and pre-heat rings for process chambers can vary by design in a number of ways that may each require specific and different installation position, fabrication recipe, and/or substrate handling protocol, the ability to automatically identify the model and design of the substrate support and/or the pre-heat ring loaded in the process chamber without the need for manual enables an increase in efficiency and optimization in the set up and use of the substrate support106and pre-heat ring207(if present), as well as corresponding set up and optimizing of relevant parameters of the process chamber the imaged substrate support and/or the pre-heat ring is disposed in. Identifying and confirming the specific corresponding model and design of the substrate support106and pre-heat ring207installed in the process chamber100that is about to be used enables the user to check and confirm the proper substrate support106handling protocol and the corresponding optimal setup for the process chamber100, based on the installed substrate support106and pre-heat ring207hardware that is to be used.

For example, corresponding fabrication recipes for substrate supports with different surface features and/or designs may be subject to different pressure and/or temperature ramping rates during processing. identifying and confirming the specific corresponding model and design of the substrate support106enables the user to check and confirm the fabrication recipe to be employed is proper and that the pressure and/or temperature ramping rate is appropriately limited. In another example, different substrate support designs may include different pocket sizes for receiving and holding the substrate108. identifying and confirming the specific corresponding model and design of the substrate support106enables the user to check and confirm the substrate handling correction that may be required to keep the substrate handling in the pocket of the substrate support106used.

In another aspect, identifying and confirming the specific corresponding model and design of the substrate support106and/or the pre-heat ring207(if present) installed in the process chamber100may advantageously assist in tracing and confirming the installed position of the substrate support106and/or the pre-heat ring207in the process chamber100is correct and proper. Substrate supports are typically mounted and balanced on a plurality pin in the process chamber100and can be installed at multiple different angles. Conventionally, installation of substrate supports traditionally requires the user to manually track and install the substrate support with certain defined portions of substrate support installed at a certain position relative to a defined portion of the processing chamber. For example, instructions for installing conventional substrate supports may include installing the substrate support by manually positioning a logo or insignia on the substrate support closer to a certain portion of the process chamber100, such as near the process gas inlet174or the gas outlet178.

However, by disposing the marking feature402on the top surface202of the substrate support106in a position viewable by the camera200and identifying the specific model and design of the imaged substrate support106using the marking feature402, the known position of the marking feature402on the substrate support106(due to the identification of the substrate support106) and the imaged position of the marking feature402relative to installed position of the substrate support106in the process chamber100, may be advantageously used to trace, confirm, and correspondingly correct (if needed) the installation position of the substrate support106to ensure the installed position of the substrate support106to be used is proper and optimal based on the specific substrate support106imaged and identified.

In another aspect, as mentioned above, the substrate support106disposed in the process chamber100may be moved vertically during processing by an actuator thereby causing the imaged size of the substrate support106to also change accordingly based on the changed distance between the substrate support106and the camera200(assuming settings such as a “zoom” by the camera200are kept constant). In certain embodiments, which can be combined with other embodiments described herein, the marking feature402disposed on the substrate support106may be used to provide a visible reference measurement point for use in providing direct scaling at the substrate support level when the substrate support106is imaged.

FIG.5shows a top view of a portion of an embodiment of the substrate support106formed with a marking feature502disposed on the rim206of the substrate support106in the second region of interest214, according to certain embodiments herein. Although some examples are described herein as applying the marking feature502to the substrate support106, aspects and embodiments of the present disclosure described herein with respect to the marking feature502and the substrate support106may be similarly applicable to applying the marking feature502to the pre-heat ring207(if present in the process chamber).

In an embodiment, which may be combined with other embodiments herein, the marking feature502disposed on the top surface202of the substrate support106may include one or more shapes or symbols formed with a dimension504having a predetermined size to enable the marking feature502to be used as a measurement scale. The portion of the marking feature502forming the dimension504must also extend along an X-Y plane parallel to the top surface202of the substrate support106to enable the dimension504of the image of the marking feature502to be imaged by the camera200and used as a scale for the respective image. For example, in an embodiment, the marking feature502may be formed as a rectangle in which the dimension504corresponds with a width “W.” When the substrate support106containing the marking feature502is imaged by the camera200, the imaged size of the mark feature502and the corresponding known size W of the dimension504may be used as a scale to calculate a correlation between the size of components in the captured image (in pixels) and the actual size of the component e.g. substrate support106and/or substrate108disposed on the substrate support106) being imaged. The imaging and use of the marking feature502on the substrate support106to provide a measurement scale may advantageously be used to assist in correcting imaging distortions in the respective image and to perform measurements of imaged components during image analysis.

In another aspect, the marking feature502may be used to automatically detect via imaging analysis rotation angles of the substrate support106based on a known home zero angle position of the substrate support106. Due to the identification of the substrate support106, the relative positioning of the marking feature402on the substrate support106when the substrate support106is in the home zero angle position can be obtained and used as a reference point. By disposing the marking feature402on the top surface202of the substrate support106in a position viewable by the camera200and comparing the imaged position of the marking feature402on the substrate support106to the known position of the marking feature402when the substrate support106is in the home zero angle position, imaging of the substrate support106may be advantageously used to detect and determine rotation angles when the substrate support106is imaged for use and to assist in further imaging measurements and analysis operations.

In yet another aspect, the marking feature502may be advantageously used to also track the positioning of the substrate support106relative to the position of the substrate108correspondingly loaded on the substrate support106or to the process chamber100. By imaging the position of the marking feature502relative to the loaded substrate support106prior to processing, the relative position and any corresponding changes or movements of the substrate108can be automatically tracked through imaging. Such tracking of the substrate support106relative to the substrate108enables the user to more easily narrow and identify the source of issues that may occur during processing. For example, when issues occur during processing, without the ability to track changes in the relative positioning of the substrate108on the substrate support106when the issue occurs, it may be difficult to ascertain whether the processing issue was caused by the process itself or associated with the substrate support106. Moreover, by providing a reference point on the relative positioning of the substrate108to the substrate support106prior to processing, imaging may then be used to determine the angle of the substrate support106that may have contributed to the processing issue.

As discussed above, the repeated use of the substrate support106in process chamber100over time may cause the SiC in the substrate support106to degrade. Specifically, changes in the SiC surface emissivity of the substrate support106were observed during the service life of the substrate support106. In certain processes, it was found that the SiC on the top surface202of the substrate support106is etched during processing thereby causing changes in the surface roughness and surface emissivity of the SiC on the surface of the substrate support106. The etching and degrading of the SiC in the substrate support106may eventually affect the performance of the substrate support106and cause the substrate support106to fail. As such, a service life for the substrate support106may therefore be defined by the point in which the reliability and performance of the substrate support106becomes affected by the degradation and changes in the surface emissivity of the SiC on the outer surface of the substrate support106.

FIG.6Ashows a top view of a portion of an embodiment of the substrate support106formed with an example of a marking feature602disposed in the second region of interest214on the rim206of the substrate support106, according to certain embodiments of the present disclosure. Although some examples are described herein as applying the marking feature602to the substrate support106, aspects and embodiments of the present disclosure described herein with respect to the marking feature602and the substrate support106may be similarly applicable to applying the marking feature602to the pre-heat ring207(if present in the process chamber) to track a service life of the pre-heat ring207via imaging.

To track the service life of the substrate support106using imaging, the marking feature602formed on the substrate support1106may be used to provide users with estimates of the remaining service life of the substrate support106the marking feature602is disposed on. The marking feature602may be disposed on the top surface202of the substrate support106in any one of the regions of interest212,214discussed herein. The marking feature602may be formed as a plurality of raised structural features each having varying heights extending from the top surface202. The marking features602may be formed in any shape or size detectable by the camera200. In the example shown inFIGS.6A and6B, the marking feature602is formed as three square prisms extending from the top surface202of the substrate support106. In alternative embodiments, the marking feature602may be formed with any number of features.

In an embodiment, which may be combined with other embodiments described herein, the marking feature602may include a first feature604with a first height606, a second feature608with a second height610, the second height610being greater than the first height606, and a third feature612with a third height614, the third height614being greater than the second height610. In an embodiment, which may be combined with other embodiments described herein, the marking feature602may be formed as reverse dimples.

Each of the first, second, and third features604,608,612of the marking feature602may be formed similar to the substrate support106such that the original surface roughness and emissivity of the marking feature602is substantially the same as the original surface roughness and emissivity of the top surface202. In certain embodiments, the marking feature602may be formed by depositing SiC on the top surface202via a deposition process, depositing a graphite core on the top surface202and coating the graphite core with SiC, or etching the top surface202in the substrate support106to form a graphite core and coating the graphite core with SiC. Forming the marking feature602to be the same or similar to the substrate support106enables the marking feature602to be etched in the same or similar manner as the substrate support106during processing. Such etching and changes in the surface roughness of the SiC coating on the substrate support106may be imaged by the camera200and analyzed to monitor the service life of the substrate support106and provide a corresponding indicator of when the substrate support106is likely to be near the end of its service life.

The service life of the substrate support106may be monitored by analyzing and tracking changes in the images of the marking feature602obtained over time as the substrate support106is used. As the marking feature602is etched by each cycle of processing of the substrate support106, the height of each of the first, second, and third features604,608,612is gradually lost with the features604,608,612becoming more planarized with the top surface202of the substrate support106. As the height of the marking feature602is lost over time, the images of each of the features604,608,612in the marking feature602obtained by the camera200will correspondingly change. Detection of such changes in the images of each of the respective features604,608,612by the camera200may then operate as respective indicators of the extent of use and hence extent of SiC degradation experienced by the respective substrate support106thus far. Knowing the extent of SiC etching and degradation can in turn be translated to an estimated remaining service life for the imaged substrate support106. The marking feature602may be formed with any number of features. The marking feature602may be formed with just one feature to provide a single indicator of when the substrate support106is near the end of its service life. The number of and height of each of the features in the marking feature602may therefore be adjusted and tailored accordingly to provide more or less indicators of the remaining service life of the substrate support106.

In an embodiment, which may be combined with other embodiments herein, the varying heights of the first, second, and third features604,608,612of the marking feature602may therefore be formed to correlate with the amount of total SiC etching typically experienced at various stages throughout the service life of the substrate support106. In an embodiment, the first, second, and third features604,608,612may be formed as indicators of the substrate support106having gone through about a third of its service life, respectively. The marking features602may be formed such that imaging of the first, second, and third features604,608,612will initially all be visible and clear when the substrate support106is new. As the substrate support106is used, all of the features604,608,612will be etched simultaneously along with the rest of the substrate support106. The first height606of the first feature604may be sized to be sufficiently etched only after about a third of the typical service life of the substrate support106has occurred, and thereby correspondingly causing changes in its imaging to be detected by the camera200. Changes in images of the first feature604include images of the first feature604becoming blurred and/or no longer being visible to the camera200. When compared to the first feature604, the greater second and third heights610,614enables the second and third features608,612to be susceptible to more etching and the imaging of the second and third features608,612will therefore remain unchanged.

The third feature612may in turn be formed with the third height614corresponding to a height of a total amount of SiC etching typically experienced by the top surface202of the substrate support106prior to failure. The third height614may be formed such that images of the third feature612obtained will also change, become blurred, and/or no longer be visible to the camera200after an amount of processing and etching of the substrate support106corresponding to about the typical service life of the substrate support has occurred. When such change in the imaging of the third feature612is imaged and detected by the camera200, an indicator that the imaged substrate support106has reached near the end of its service life and should therefore be changed may be provided to the user. The imaging and analysis to check the marking features602for indicators of the remaining service life of the substrate support106may be automatically employed prior to each use of the substrate support106to minimize the chances of a failure of the substrate support106during use.

In another embodiment, the third feature612may be formed with a third height614that corresponds to just a little less than a total amount of SiC etching typically experienced by a substrate support prior to failure. Forming the third height614to be just a little less than a typical total etch amount prior to failure allows the third feature612to operate as an early warning indicator that the imaged substrate support106is about to reach the end of its service life and should be changed. Having a slightly earlier warning indicator to change the substrate support106prior to failure may also minimize the chance of an actual failure of the substrate support106during use in processing (and possibly thereby ruining the components being fabricated) before the indicator from the third feature612is detected and the substrate support106changed.

The second height610of the second feature608may be formed to be about double the first height606. When a change in the imaging of the second feature608is accordingly imaged and detected by the camera200after use, an indicator that about two thirds of the service life of the imaged substrate support106has been used (or approximately a third of the service life remains) may be provided to the user.

In summation, implementations of the above disclosure described herein provide an apparatus and method for identifying a substrate support and a pre-heat ring disposed in a process chamber via imaging and obtaining information related to the imaged substrate support and pre-heat ring in the process chamber thereof. Methods and apparatus for identifying the substrate support and the pre-heat ring generally include disposing a marking feature on a top surface of the substrate support and the pre-heat ring and imaging the marking features when the substrate support and pre-heat ring are disposed inside the process chamber to identify the specific model of the substrate support and pre-heat ring disposed in the process chamber. Each marking feature to be disposed on a substrate support corresponds with one specific model (or design) of a plurality of different substrate supports. Likewise, each marking feature to be disposed on a pre-heat ring corresponds with one specific model (or design) of a plurality of different pre-heat rings. When the specific marking feature on the substrate support is imaged, the marking feature is analyzed and may then be used to identify the model of the respective substrate support or pre-heat ring the imaged marking feature is disposed on. Marking features may also be disposed on the substrate support and/or the pre-heat ring to provide information related to the substrate support, the pre-heat ring, and/or the imaging of the substrate support and the pre-heat ring. Information that may be provided via imaging of marking features on the substrate support and pre-heat ring include without limitation information related to a reference measurement for direct scaling at the substrate support/pre-heat ring level for use with imaging of the substrate support and pre-heat ring in the process chamber, a reference point for detection and determination of rotation angles by the substrate support in the process chamber, a reference point for detection and tracing of the installation position of the substrate support and the pre-heat ring in the process chamber, and/or an indication of when the substrate support and/or the pre-heat ring is likely to be near the end of its service life.

Embodiments of the disclosure have been described above with reference to specific embodiments and numerous specific details are set forth to provide a more thorough understanding of the invention. Persons skilled in the art, however, will understand that various modifications and changes may be made thereto without departing from the broader spirit and scope of the invention. The foregoing description and drawings are, accordingly, to be regarded in an illustrative rather than a restrictive sense.