Image-based plasma sheath profile detection on plasma processing tools

Abstract

To provide a system and a method for detecting and monitoring a plasma sheath profile within a substrate processing chamber.SOLUTION: A system has a system controller comprising an image processing module configured to: receive an image, captured by an imaging device such as a camera 320, of a plasma environment within a substrate processing chamber 300 during processing of a substrate 316; and extract one or more features of the image indicative of a plasma sheath formed in the plasma environment during the processing of the substrate. The system controller is configured to: determine a plasma sheath profile based on the one or more features extracted from the image; and selectively adjust at least one processing parameter related to the processing of the substrate based on the plasma sheath profile.SELECTED DRAWING: Figure 3A

Description

[Technical field]

[0001] [CROSS REFERENCE TO RELATED APPLICATIONS] This application claims priority to U.S. Patent Application No. 15 / 991,021, filed May 29, 2018, the entire disclosure of which is incorporated herein by reference. FIELD OF THE DISCLOSURE This disclosure relates to substrate processing, and more particularly to detecting and monitoring a plasma sheath profile within a substrate processing chamber. [Background technology]

[0002] The discussion of the background art provided herein is intended to present the contents of the present disclosure generally, and the inventions of the presently named inventors are not admitted expressly or impliedly as prior art to the present disclosure to the extent that they are described in this Background section and in a manner that is not prior art at the time of filing.

[0003] A substrate processing system may be used to process a substrate, such as a semiconductor wafer. Exemplary processes that may be performed on the substrate include, but are not limited to, chemical vapor deposition (CVD), atomic layer deposition (ALD), conductor etching, and / or other etching, deposition, or cleaning processes. The substrate may be disposed on a substrate support, such as a pedestal, electrostatic chuck (ESC), or the like, in a processing chamber of the substrate processing system. During etching, a gas mixture may be introduced into the processing chamber, and a plasma may be used to initiate a chemical reaction.

[0004] During substrate processing using plasma, a plasma boundary layer (called a plasma sheath) is formed above the surface of the substrate. The plasma sheath thickness depends on various factors, including but not limited to plasma density, electron temperature, driving voltage, etc. By way of example only, the plasma sheath thickness may vary from a fraction of a millimeter to several millimeters. Summary of the Invention

[0005] The system includes an image processing module configured to receive an image of a plasma environment in the substrate processing chamber captured by the imaging device during substrate processing and extract one or more features of the image indicative of a plasma sheath formed in the plasma environment during substrate processing. The control module is configured to determine a plasma sheath profile based on the one or more features extracted from the image and selectively adjust at least one process parameter for the substrate processing based on the plasma sheath profile.

[0006] In another aspect, the extracted one or more features correspond to a contrast between the bulk plasma region and the plasma sheath region. The extracted one or more features correspond to a line between the bulk plasma region and the plasma sheath region. The control module is configured to compare the plasma sheath profile to a reference profile and selectively adjust at least one process parameter based on a difference between the plasma sheath profile and the reference profile. The control module is configured to compare the plasma sheath profile to the reference line and selectively adjust at least one process parameter based on a difference between the plasma sheath profile and the reference line. The control module is configured to determine a flatness of the plasma sheath profile to selectively adjust the at least one process parameter.

[0007] In other features, the at least one process parameter corresponds to a height of an edge ring, and the control module is configured to adjust the height of the edge ring based on one or more features extracted from the image. The at least one process parameter corresponds to a power provided to the edge ring, and the control module is configured to adjust the power provided to the edge ring based on one or more features extracted from the image. The system further includes an imaging device, the imaging device disposed to view the plasma environment above the edge region of the substrate through an opening in a sidewall of the substrate processing chamber. The system further includes a shutter disposed to selectively open and close within the opening in the sidewall of the substrate processing chamber. The control module is configured to selectively open and close the shutter to enable the imaging device to capture the image.

[0008] The method includes capturing an image of a plasma environment in a substrate processing chamber during substrate processing, extracting one or more features of the image indicative of a plasma sheath formed in the plasma environment during substrate processing, determining a plasma sheath profile based on the one or more features extracted from the image, and selectively adjusting at least one process parameter related to the substrate processing based on the plasma sheath profile.

[0009] In other features, the extracted one or more features correspond to a contrast between the bulk plasma region and the plasma sheath region. The extracted one or more features correspond to a line between the bulk plasma region and the plasma sheath region. Selectively adjusting the at least one process parameter includes comparing the plasma sheath profile to a reference profile and selectively adjusting the at least one process parameter based on a difference between the plasma sheath profile and the reference profile. Selectively adjusting the at least one process parameter includes comparing the plasma sheath profile to a reference line and selectively adjusting the at least one process parameter based on a difference between the plasma sheath profile and the reference line. Selectively adjusting the at least one process parameter includes determining a flatness of the plasma sheath profile.

[0010] In other features, the at least one process parameter corresponds to a height of an edge ring, and selectively adjusting the at least one process parameter includes adjusting the height of the edge ring based on one or more features extracted from the image. The at least one process parameter corresponds to a power supplied to the edge ring, and selectively adjusting the at least one process parameter includes adjusting the power supplied to the edge ring based on one or more features extracted from the image. The method further includes selectively opening and closing a shutter in an opening in a sidewall of the substrate processing chamber to allow an imaging device to capture the image.

[0011] Further areas of applicability of the present disclosure will become apparent from the detailed description, the claims, and the drawings. The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the disclosure. [Brief description of the drawings]

[0012] The present disclosure will become better understood from the detailed description and the accompanying drawings.

[0013] [Figure 1] FIG. 2 is a functional block diagram of an exemplary processing chamber according to the present disclosure.

[0014] [Figure 2A] 1 illustrates an exemplary movable edge ring in a lowered position according to the present disclosure.

[0015] [Figure 2B] 1 illustrates an exemplary movable edge ring in a raised position according to the present disclosure.

[0016] [Figure 2C] 1 illustrates an exemplary motorized edge ring according to the present disclosure.

[0017] [Figure 3A] 1 illustrates an exemplary processing chamber according to the present disclosure.

[0018] [Figure 3B] FIG. 2 is a functional block diagram of an example controller according to the present disclosure.

[0019] [Figure 4A] 13 is an example image of a plasma sheath profile according to the present disclosure.

[0020] [Figure 4B] 1 illustrates an exemplary characteristic of a plasma sheath profile according to the present disclosure.

[0021] [Figure 4C] 4 is another exemplary feature of a plasma sheath profile according to the present disclosure.

[0022] [Diagram 5] 1 illustrates an exemplary method for determining a plasma sheath profile according to the present disclosure.

[0023] In the drawings, reference numbers may be used multiple times to identify similar and / or identical elements. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0024] The outcome of substrate processing using plasma depends on the plasma sheath profile (e.g., the thickness of the plasma sheath across the substrate surface). For example, in a plasma etching process, the plasma sheath profile can affect the etch rate. Thus, the uniformity of the process depends on the flatness of the plasma sheath. Thus, a uniform plasma sheath thickness is desirable to minimize process non-uniformity.

[0025] In some examples, the plasma sheath profile may be evaluated after processing. For example, each completed substrate may be inspected following substrate processing to determine etch uniformity, tilting, etc. Various adjustments may then be made to process parameters and / or process chamber parameters on a feed-forward basis to attempt to adjust the plasma sheath profile for the next substrate processing. However, evaluating and compensating for non-uniformities in the plasma sheath profile in this manner may increase costs and reduce processing efficiency and throughput.

[0026] A plasma sheath profile system and method according to the principles of the present disclosure facilitates determining a plasma sheath profile during substrate processing and controlling the plasma sheath profile accordingly. For example, an imaging device, such as a camera, is positioned to image and monitor the plasma sheath in the processing chamber. The camera may be installed outside the processing chamber and positioned to observe the plasma sheath through a window in a sidewall of the processing chamber. The plasma sheath profile may be determined and, in some examples, controlled according to images captured by the camera during processing. In this manner, processing non-uniformities with respect to the plasma sheath profile are minimized and processing costs and processing times are reduced.

[0027] In some examples, the substrate support of the substrate processing system may include a movable and / or motorized edge ring. Some aspects of the substrate processing that affect the etch rate and etch non-uniformity (e.g., plasma sheath profile, process gas flow pattern, etc.) may vary depending on the height of the edge ring. For example, the overall etch rate may change as the distance between the top surface of the substrate and the bottom surface of the gas distribution apparatus increases. Furthermore, the etch rate may vary from the center of the substrate to the outer periphery of the substrate. Thus, in examples including a movable edge ring, the edge ring may be raised and / or lowered depending on the measured plasma sheath profile to further minimize the process non-uniformity. Similarly, the plasma sheath profile may be further controlled by varying the power supplied to the motorized edge ring.

[0028] Referring now to FIG. 1, an exemplary substrate processing system 100 is shown. By way of example only, the substrate processing system 100 may be used to perform etching using RF plasma and / or other suitable substrate processes. The substrate processing system 100 includes a processing chamber 102 that surrounds the other components of the substrate processing system 100 and contains the RF plasma. The processing chamber 102 includes an upper electrode 104 and a substrate support 106 that includes an electrostatic chuck (ESC). During operation, a substrate 108 is disposed on the substrate support 106. Although a particular substrate processing system 100 and processing chamber 102 are shown as examples, the principles of the present disclosure may be applied to other types of substrate processing systems and chambers (such as substrate processing systems that generate plasma in-situ, substrate processing systems that implement remote plasma generation and delivery (e.g., using plasma tubes, microwave tubes), etc.).

[0029] By way of example only, the upper electrode 104 may include a gas distribution device, such as a showerhead 109, for introducing and distributing process gases. The showerhead 109 may include a stem portion including one end coupled to the top surface of the processing chamber 102. A base portion is generally cylindrical and extends radially outward from the opposite end of the stem portion away from the top surface of the processing chamber 102. A substrate-facing surface or faceplate of the base of the showerhead 109 includes a number of holes through which process or purge gases flow. Alternatively, the upper electrode 104 may include a conductive plate, and the process gases may be introduced in another manner.

[0030] The substrate support 106 includes a conductive base plate 110 that functions as a bottom electrode. The base plate 110 supports a ceramic layer 112. In some examples, the ceramic layer 112 may include a heating layer, such as a ceramic multi-zone heating plate. A thermally resistant layer 114 (e.g., a bonding layer) may be disposed between the ceramic layer 112 and the base plate 110. The base plate 110 may include one or more coolant channels 116 for flowing a coolant through the base plate 110. In some examples, a protective seal 176 may be provided around the periphery of the bonding layer 114 between the ceramic layer 112 and the base plate 110.

[0031] The RF generating system 120 generates and outputs an RF voltage to either the upper electrode 104 or the lower electrode (e.g., the base plate 110 of the substrate support 106). The other of the upper electrode 104 and the base plate 110 may be DC grounded, AC grounded, or floating. By way of example only, the RF generating system 120 may include an RF voltage generator 122 that generates an RF voltage that is supplied to the upper electrode 104 or the base plate 110 by a matched distribution network 124. In other examples, the plasma may be generated inductively or remotely. As shown for illustrative purposes, the RF generating system 120 corresponds to a capacitively coupled plasma (CCP) system, although the principles of the present disclosure may be implemented in other suitable systems (by way of example only, a transformer coupled plasma (TCP) system, a CCP cathode system, a remote microwave plasma generating supply system, etc.).

[0032] The gas supply system 130 includes one or more gas sources, gas source 132-1, gas source 132-2, ..., and gas source 132-N (collectively, gas source 132), where N is an integer greater than zero. The gas sources supply one or more etching gases, carrier gases, inert gases, and mixtures thereof. The gas source 132 may supply a purge gas. The gas sources 132 are connected to a manifold 140 by valves 134-1, valves 134-2, ..., and valves 134-N (collectively, valves 134) and mass flow controllers 136-1, mass flow controllers 136-2, ..., and mass flow controllers 136-N (collectively, mass flow controllers 136). An output of the manifold 140 is supplied to the process chamber 102. By way of example only, an output of the manifold 140 is supplied to the showerhead 109.

[0033] The temperature controller 142 may be connected to a number of heating elements 144, such as thermal control elements (TCEs), disposed on the ceramic layer 112. For example, the heating elements 144 may include, but are not limited to, macro-heating elements corresponding to each zone of a multi-zone heating plate and / or an array of micro-heating elements disposed across multiple zones of a multi-zone heating plate. The temperature controller 142 may be used to control the number of heating elements 144 to control the temperature of the substrate support 106 and the substrate 108.

[0034] The temperature controller 142 may be in communication with the coolant assembly 146 to control the flow of coolant through the passages 116. For example, the coolant assembly 146 may include a coolant pump and a reservoir. The temperature controller 142 operates the coolant assembly 146 to selectively flow coolant through the passages 116 to cool the substrate support 106.

[0035] Valves 150 and pumps 152 may be used to evacuate reactants from the processing chamber 102. A system controller 160 may be used to control the components of the substrate processing system 100. A robot 170 may be used to transfer substrates to and from the substrate support 106. For example, the robot 170 may transfer substrates between the substrate support 106 and a load lock 172. Although shown as a separate controller, the temperature controller 142 may be implemented within the system controller 160.

[0036] The substrate support 106 includes an edge ring 180. In some examples, the edge ring 180 according to principles of the present disclosure is movable (e.g., vertically up and down) relative to the substrate 108. For example, the edge ring 180 may be controlled by an actuator responsive to the system controller 160. In some examples, a user may input control parameters (e.g., erosion rate) to the system controller 160 via a user interface 184, which may include one or more input mechanisms, a display screen, or the like.

[0037] An imaging device, such as a camera 186, is positioned to monitor the plasma sheath within the processing chamber 102. For example, the camera 186 is positioned to view the plasma sheath through a window 188 in a sidewall 190 of the processing chamber 102. The camera 186 communicates information about the plasma sheath to the system controller 160, as described in more detail below.

[0038] In some examples, the principles of the disclosure may be implemented using a substrate support 200 having a movable edge ring configuration as shown in FIGS. 2A and 2B. The exemplary substrate support 200 has a substrate 204 disposed thereon. The substrate support 200 may comprise a base or pedestal having an inner portion 208 (e.g., corresponding to an ESC) and an outer portion 212. In an example, the outer portion 212 may be independent of and movable relative to the inner portion 208. The substrate 204 is disposed in the inner portion 208 for processing. A controller 216 (e.g., corresponding to the system controller 160) communicates with one or more actuators 220 to selectively raise and lower the edge ring 224 to adjust the height of the edge ring 224 relative to the substrate support 200. By way of example only, the edge ring 224 is shown in a fully lowered position in FIG. 2A and in an exemplary fully raised position in FIG. 2B. As shown, the actuator 220 corresponds to a pin actuator configured to selectively extend and retract the pins 228 in a vertical direction. In other examples, other suitable types of actuators may be used. By way of example only, the edge ring 224 corresponds to a ceramic edge ring or a quartz edge ring. In FIG. 2A , the controller 216 communicates with the actuator 220 to directly raise and lower the edge ring 224 via the pins 228. In some examples, the inner portion 208 is operable relative to the edge ring 224. The edge ring 224 may have one or more associated erosion rates, which will be described in more detail below.

[0039] In other examples, the principles of the disclosure may be implemented using a substrate support 200 having a motorized edge ring configuration as shown in FIG. 2C. In this example, the controller 216 is further configured to selectively supply RF power (e.g., via an RF generator 232 and an RF matching network 236) to the edge ring 224. In some examples, the edge ring 224 may be both movable and motorized.

[0040] 3A and 3B, an exemplary processing chamber 300 according to the present disclosure is shown. The processing chamber 300 encloses a substrate support 304 with a processing space 308. As shown, the substrate support 304 includes an edge ring 312 disposed to surround a substrate 316 disposed on the substrate support 304. In some examples, the edge ring 312 may be configured to be raised and lowered as described above in FIGS. 2A and 2B.

[0041] One or more cameras (e.g., high resolution digital cameras) 320 are positioned to monitor the process space 308 above the substrate 316. Although two cameras 320 are shown positioned to image a portion of the process space 308 above the edge region of the substrate 316, one or more cameras 320 may be provided. For example, the edge of the substrate 316 is more susceptible to bending of the plasma sheath. Thus, the position and viewing angle of the camera 320 is selected to maximize coverage of the edge of the substrate 316 to detect bending of the plasma sheath. Furthermore, although the camera 320 is shown aligned with the edge region of the substrate 316 in FIG. 3A, in other examples, the camera 320 may be positioned at a different location (e.g., centered with respect to the substrate 316) to monitor the entire process space 308 above the substrate 316.

[0042] The camera 320 is positioned to view the processing space 308 through an opening 324 in a sidewall 328 of the processing chamber 300. For example, the camera 320 is positioned to view the processing space 308 through a window 332 disposed in the opening 324. The window 332 may be constructed of glass or other suitable transparent material and is vacuum sealed.

[0043] The window 332 may be susceptible to wear and / or damage due to exposure to the plasma and other materials in the process chamber 300. Thus, a plasma-resistant mechanical door or shutter 336 may be provided to protect the window 332 from the environment in the process chamber 300. For example, the shutter 336 may be constructed of the same material as the sidewall 328 of the process chamber 300. The shutter 336 may be configured to be selectively opened to allow the camera 320 to capture images of the process space 308 and selectively closed to protect the window 332 from the plasma environment and extend the useful life of the window 332. For example, the shutter 336 may be selectively actuated in response to a control signal from a controller 340 (which may correspond to the system controller 160). In some examples, the shutter 336 corresponds to a gate valve, such as a vacuum gate valve.

[0044] The camera 320 is configured to selectively capture an image of the processing space 308 through the window 332 (e.g., in response to a control signal received from the controller 340), and the controller 340 is configured to detect a plasma sheath based on the captured image, determine a plasma sheath profile, and adjust process parameters based on the plasma sheath profile. Differences between the properties of the bulk plasma in the processing space 308 (e.g., electron temperature, ion concentration, etc.) and the properties of the plasma sheath region adjacent to the substrate 316 can be detected based on the captured image, and the plasma sheath can be identified accordingly. For example, due to the differences between the various properties, visible and ultraviolet light emissions in the plasma sheath region are different compared to the bulk plasma and can be identified (i.e., contrasted) in the captured image. In this manner, the controller 340 is configured to extract features from the captured image indicative of the plasma sheath, and selectively adjust process parameters (e.g., edge ring height, plasma density profile, power delivered to the upper and / or lower electrodes, process gas flow rates, side gas adjustments, coil adjustments, etc.) based on the detected plasma sheath. In some examples, the camera 320 may implement one or more optical filters to enhance the contrast between the bulk plasma and the plasma sheath region.

[0045] 3B, the controller 340 includes an image processing module 344 configured to extract features of an image captured by the camera 320 that may be indicative of a plasma sheath. Although shown internal to the controller 340, in some examples, the camera 320 may include the image processing module 344. By way of example only, the image processing module 344 may be configured to identify lines in the captured image that are indicative of contrast between the bulk plasma and the plasma sheath region, as described in more detail below. In some examples, the image processing module 344 may filter the captured image and post-process the captured image to enhance contrast between the bulk plasma and the plasma sheath region.

[0046] The plasma sheath detection control module 348 receives the extracted features from the image processing module 344. In other aspects, the plasma sheath detection control module 348 may receive the captured images directly from the camera 320 and / or may receive the captured images from the image processing module 344 following post-processing. That is, the plasma sheath detection control module 348 may be configured to receive the extracted features and / or perform feature extraction on the captured images. For example, the plasma sheath detection control module 348 may perform feature extraction according to an image processing algorithm stored in the memory 352.

[0047] The plasma sheath detection control module 348 determines a plasma sheath profile based on the extracted features and selectively adjusts one or more process parameters based on the plasma sheath profile. For example, the plasma sheath detection control module 348 may adjust the process parameters according to the flatness of the plasma sheath profile. In some examples, the plasma sheath detection control module 348 compares the plasma sheath profile to a predefined reference profile, such as a baseline (e.g., a flat line located at a predefined distance above the substrate surface), and determines whether the difference between the plasma sheath profile and the baseline is greater than a threshold value. For example, the plasma sheath detection control module 348 may calculate the distance between the plasma sheath profile at the edge of the substrate and the baseline, the maximum variance between the plasma sheath profile and the baseline, etc.

[0048] In one example, the plasma sheath detection control module 348 selectively raises and lowers the edge ring 312 (e.g., using the edge ring actuator control module 356) to adjust the plasma sheath profile. For example, the plasma sheath detection control module 348 is configured to raise and lower the edge ring 312 based on the measured flatness of the plasma sheath profile, control the camera 320 to capture additional images of the plasma sheath, and determine the flatness of the plasma sheath profile at the position where the edge ring 312 is adjusted until a plasma sheath profile of a desired flatness is achieved (e.g., the difference between the baseline and the plasma sheath profile is less than a threshold value). The plasma sheath detection control module 348 may adjust other process parameters (e.g., plasma density profile, power supplied to the lower and / or upper electrodes, process gas flow rates, side gas adjustments, coil adjustments, etc.) as described above. For example, the plasma sheath detection control module 348 may control the RF generator 232 to adjust (e.g., increase or decrease) the RF power supplied to the edge ring 312 to adjust the thickness of the plasma sheath above the edge region of the substrate 316.

[0049] The plasma sheath detection control module 348 is further configured to control the shutter actuator control module 360 ​​to selectively open and close the shutter 336. For example, the plasma sheath detection control module 348 selectively opens the shutter 336 to allow the camera 320 to capture an image of the process space 308, and then closes the shutter 336 to protect the window 332 from the plasma environment. Thus, the shutter 336 may be opened for only a short period of time (e.g., less than one second) for image capture. The shutter 336 may be opened for image capture to adjust the plasma sheath profile periodically (e.g., weekly or monthly following the processing of a predetermined number of substrates) in response to a user input periodically (e.g., at one-minute intervals) during the processing of one substrate.

[0050] 4A, exemplary images 400 and 404 of a plasma sheath captured by a camera (e.g., camera 320) are shown. As shown in image 400, the plasma sheath profile 408 bends downward toward the edge 412 of the substrate 416. In other examples, the plasma sheath profile 408 may bend upward away from the edge 412 of the substrate 416. A downward or upward bend may indicate that the edge ring is too low or too high, respectively, relative to the substrate 416. Conversely, as shown in image 404, the plasma sheath profile 408 is relatively flat. For example, image 404 may correspond to an image captured following adjustment of the edge ring height or other process parameters to adjust the plasma sheath profile 408.

[0051] 4B and 4C show example features (e.g., lines 420 and 424) extracted from the captured image of the plasma sheath. The reference extracted features are shown for the outer portion of the substrate support 428. As shown in FIG. 4B, the line 420 corresponding to the measured plasma sheath profile bends downward toward the outer edge 412 of the substrate 416. Conversely, as shown in FIG. 4C, the line 424 is relatively flat compared to the line 420 and does not bend downward. For example, the line 424 may correspond to the plasma sheath profile after raising the edge ring 432 to adjust the plasma sheath profile. In this example, the edge ring 432 may be adjusted in response to a comparison of the lines 420 and 424 to the reference line 436, as described above.

[0052] 5, an exemplary method 500 for determining a plasma sheath profile according to the present disclosure begins at 504. At 508, a substrate is placed on a substrate support in a processing chamber. At 512, a plasma process (e.g., a plasma etch process) is performed on the substrate. At 516, the method 500 (e.g., controller 340) determines whether to capture an image of the plasma sheath in the processing chamber. If true, the method 500 continues at 520; if false, the method 500 continues at 524. At 524, the method (e.g., controller 340) determines whether the plasma process is complete. If true, the method 500 ends at 528. If false, the method 500 continues at 512.

[0053] At 520, the method 500 (e.g., the controller 340) opens a shutter (e.g., the shutter(s) 336) so that an image of the plasma sheath is captured through an opening in the sidewall of the processing chamber. At 532, the method 500 (e.g., the camera 320) captures an image of the plasma sheath. At 536, the method 500 (e.g., the controller 340) closes the shutter. At 540, the method 500 (e.g., the controller 340) analyzes the captured image to determine a plasma sheath profile. For example, the method 500 determines the flatness of the plasma sheath profile. At 544, the method 500 (e.g., the controller 340) determines whether to adjust one or more process parameters (e.g., the edge ring height, the RF power delivered to the edge ring, etc.) in response to the measured flatness of the plasma sheath profile. If true, the method 500 continues to 548. If false, the method 500 continues to 524.

[0054] At 548, method 500 (e.g., controller 340) adjusts one or more process parameters to adjust the plasma sheath profile. For example, method 500 adjusts the edge ring height. Method 500 then continues to 520 and repeats steps 520, 532, 536, 540, and 544. That is, after adjusting the edge ring height, method 500 takes another image of the plasma sheath to determine whether the edge ring height should be further adjusted to achieve a desired flatness of the plasma sheath profile.

[0055] The foregoing description is merely exemplary in nature and is not intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure may be implemented in various forms. Thus, while the present technology includes specific examples, other variations will become apparent upon consideration of the drawings, the specification, and the following claims, and thus the true scope of the present technology should not be so limited. It should be understood that one or more steps in a method may be performed in different orders (or simultaneously) without changing the principles of the present technology. Furthermore, although each embodiment is described above as having certain features, one or more of those features described with respect to the embodiments of the present disclosure may be implemented in other embodiments and / or in combination with features of other embodiments (even if the combination is not specified). In other words, the described embodiments are not mutually exclusive, and permutations of one or more embodiments with each other remain within the scope of the present disclosure.

[0056] Spatial and functional relationships between elements (e.g., between modules, between circuit elements, between semiconductor layers, etc.) are described using various terms including "connected," "engaged," "coupled," "adjacent," "adjacent," "on," "above," "below," and "disposed." When a relationship between a first element and a second element is described in the above disclosure, unless expressly stated as "direct," the relationship may be a direct relationship where there are no intervening elements between the first element and the second element, but may also be an indirect relationship where there are one or more intervening elements (spatial or functional) between the first element and the second element. In this specification, the phrase at least one of A, B, and C should be interpreted as meaning logic using non-exclusive logic, OR, (A OR B OR C), and not as meaning "at least one of A, at least one of B, and at least one of C."

[0057] In some embodiments, the controller is part of a system that may be part of the above examples. Such systems may include semiconductor processing equipment including processing tools, chambers, processing platforms, and / or specific processing components (wafer pedestals, gas flow systems, etc.). These systems may be integrated with electronics to control their operation before, during, and after processing of semiconductor wafers or substrates. This electronics may refer to a "controller" that may control various components or subcomponents of the system. The controller may be programmed to control the processes described herein, such as supply of process gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow settings, fluid supply settings, position operation settings, wafer loading and unloading to and from tools and other transport tools, and / or wafer loading and unloading to and from load locks connected or coupled to the specific system, depending on the processing conditions and / or type of system.

[0058] In general, a controller may be defined as electronic equipment having various integrated circuits, logic, memory, and / or software that receive instructions, issue instructions, control operations, enable cleaning operations, and enable endpoint measurements. Integrated circuits may include chips in firmware format that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and / or one or more microprocessors or microcontrollers that execute program instructions (e.g., software). Program instructions may be instructions communicated to the controller in the form of various personalizations (or program files) that define operational parameters for performing a particular process on or for a semiconductor wafer or for a system. In some embodiments, the operational parameters may be part of a recipe defined by a process engineer to achieve one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or one or more processing steps during the manufacture of a wafer die.

[0059] In some embodiments, the controller may be part of or coupled to a computer integrated or coupled with the system, or otherwise networked or combined with the system. For example, the controller may be in the "cloud" that allows remote access of wafer processing, or may be all or part of a fab host computer system. The computer may allow remote access to the system to monitor the progress of a manufacturing operation, review the history of past manufacturing operations, review trends or performance metrics from multiple manufacturing operations, modify parameters of a current process, set processing steps following a current process, or start a new process. In some examples, a remote computer (e.g., a server) may provide a process recipe to the system over a network that may include a local network or the Internet. The remote computer may include a user interface that allows entry or programming of parameters and / or settings that are then communicated from the remote computer to the system. In some examples, the controller receives instructions in the form of data that specify parameters for each processing step to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process being performed and the type of tool the controller is configured to connect to or control. Thus, as discussed above, the controller may be distributed, for example, by including one or more individual controllers networked together and cooperating for a common purpose, such as a process or control as described herein. An example of a controller distributed for such a purpose would be one or more integrated circuits on the chamber that are located remotely (e.g., at the platform level or as part of a remote computer) and communicate with one or more integrated circuits that cooperate to control a process in the chamber.

[0060] Without being limited thereto, example systems may include plasma etch chambers or modules, deposition chambers or modules, spin rinse chambers or modules, metal plating chambers or modules, clean chambers or modules, bevel edge etch chambers or modules, physical vapor deposition (PVD) chambers or modules, chemical vapor deposition (CVD) chambers or modules, atomic layer deposition (ALD) chambers or modules, atomic layer etch (ALE) chambers or modules, ion implantation chambers or modules, track chambers or modules, and other semiconductor processing systems that may be related to or used in the fabrication and / or manufacturing of semiconductor wafers.

[0061] As described above, depending on the process steps being performed by the tool, the controller may be in communication with one or more of other tool circuits or tool modules, other tool components, cluster tools, other tool interfaces, adjacent tools, nearby tools, tools installed throughout the factory, a main computer, another controller, or tools used to transport materials to and from tool locations and / or load ports in a semiconductor manufacturing factory.

Claims

1. 1. A system comprising: an image processing module configured to: (i) receive a plurality of images, captured by a plurality of cameras, of a plasma environment in a substrate processing chamber during processing of a substrate; and (ii) extract one or more features from the plurality of images indicative of a plasma sheath formed in the plasma environment during processing of the substrate; a control module configured to: (i) determine a plasma sheath profile based on the one or more features extracted from the plurality of images; and (ii) selectively adjust at least one process parameter for processing the substrate based on the plasma sheath profile; Equipped with the plurality of cameras are positioned at offset positions on the substrate to image portions of the plasma environment above edge regions of the substrate; the positions and viewing angles of the cameras are selected to cover multiple edge regions of the substrate and to detect bending of the plasma sheath; system.

2. 10. The system of claim 1, A system wherein one of the one or more characteristics corresponds to a contrast between a bulk plasma region and a plasma sheath region.

3. 3. The system of claim 2, The system, wherein the one of the one or more features corresponds to a line between the bulk plasma region and the plasma sheath region.

4. 10. The system of claim 1, The system, wherein the control module is configured to (i) compare the plasma sheath profile to a reference profile, and (ii) selectively adjust the at least one process parameter based on a difference between the plasma sheath profile and the reference profile.

5. 10. The system of claim 1, The system, wherein the control module is configured to (i) compare the plasma sheath profile to a baseline, and (ii) selectively adjust the at least one processing parameter based on a difference between the plasma sheath profile and the baseline.

6. 10. The system of claim 1, The system, wherein the control module is configured to determine a flatness of the plasma sheath profile to selectively adjust the at least one process parameter.

7. 10. The system of claim 1, (i) the at least one processing parameter corresponds to a height of an edge ring; and (ii) the control module is configured to adjust the height of the edge ring based on the one or more features extracted from the plurality of images.

8. 10. The system of claim 1, (i) the at least one processing parameter corresponds to power supplied to an edge ring; and (ii) the control module is configured to adjust the power supplied to the edge ring based on the one or more features extracted from the plurality of images.

9. 10. The system of claim 1, further comprising: a plurality of cameras positioned to view the plasma environment above an edge region of the substrate through openings in a sidewall of the substrate processing chamber.

10. 10. The system of claim 9, further comprising: A system comprising a shutter positioned to selectively open and close within the opening in the sidewall of the substrate processing chamber.

11. 11. The system of claim 10, The control module is configured to selectively open and close the shutters to enable the cameras to capture the images.

12. 1. A method comprising: capturing a plurality of images of a plasma environment within a substrate processing chamber while the substrate is being processed; extracting one or more features from the plurality of images indicative of a plasma sheath formed in the plasma environment during processing of the substrate; determining a plasma sheath profile based on the one or more features extracted from the plurality of images; Selectively adjusting at least one process parameter for processing the substrate based on the plasma sheath profile; Including, a plurality of cameras positioned at offset positions from the substrate to image portions of the plasma environment above edge regions of the substrate; the positions and viewing angles of the cameras are selected to cover multiple edge regions of the substrate and to detect bending of the plasma sheath; method.

13. 13. The method of claim 12, The method, wherein one of the one or more characteristics corresponds to a contrast between a bulk plasma region and a plasma sheath region.

14. 14. The method of claim 13, The method, wherein the one of the one or more features corresponds to a line between the bulk plasma region and the plasma sheath region.

15. 13. The method of claim 12, The method, wherein selectively adjusting the at least one process parameter includes comparing the plasma sheath profile to a reference profile and selectively adjusting the at least one process parameter based on a difference between the plasma sheath profile and the reference profile.

16. 13. The method of claim 12, The method, wherein selectively adjusting the at least one process parameter includes comparing the plasma sheath profile to a baseline and selectively adjusting the at least one process parameter based on a difference between the plasma sheath profile and the baseline.

17. 13. The method of claim 12, The method, wherein selectively adjusting the at least one process parameter includes determining a flatness of the plasma sheath profile.

18. 13. The method of claim 12, (i) the at least one processing parameter corresponds to a height of an edge ring; and (ii) selectively adjusting the at least one processing parameter includes adjusting the height of the edge ring based on the one or more features extracted from the plurality of images.

19. 13. The method of claim 12, (i) the at least one processing parameter corresponds to power supplied to an edge ring; and (ii) selectively adjusting the at least one processing parameter includes adjusting the power supplied to the edge ring based on the one or more features extracted from the plurality of images.

20. 13. The method of claim 12, further comprising: The method includes selectively opening and closing a shutter in an opening in a sidewall of the substrate processing chamber to allow an imaging device to capture the plurality of images.

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