Use of signal filtering schemes in high tcr based control

Abstract

A controller for controlling the temperature of a first substrate support in a substrate processing system includes: a resistance calculation module for calculating a first resistance of a first heater element among a plurality of heater elements of the first substrate support; a temperature calculation module for calculating a first temperature of the first heater element based on the calculated first resistance; and a filter module for filtering a first signal corresponding to the calculated first resistance. The temperature calculation module selectively causes the filter module to filter the first signal in response to determining whether at least one condition associated with the operation of the substrate processing system is met.

Description

[Technical Field]

[0001] This disclosure relates to temperature control during substrate processing. [Cross-reference to related applications]

[0002] This application claims the rights of U.S. Provisional Application No. 63 / 180,883, filed April 28, 2021. The entire disclosure of the above-cited application is incorporated herein by reference. [Previous Technology]

[0003] The prior art description provided herein is intended to provide a general overview of the content of this disclosure. The achievements of currently listed inventors described in this prior art section, as well as descriptions that may not have otherwise qualified as prior art at the time of application, are not intended to be considered prior art relative to this disclosure.

[0004] A substrate processing system can be used to process substrates, such as semiconductor wafers. Examples of substrate processing include etching, deposition, photoresist removal, etc. During processing, the substrate is placed on a substrate support, such as an electrostatic chuck. One or more process gases can be introduced into a processing chamber. One or more process gases can be delivered to the processing chamber via a gas delivery system. In some systems, the gas delivery system includes a manifold connected to a spray head located in the processing chamber via one or more conduits. [Summary of the Invention]

[0005] A controller for controlling the temperature of a first substrate support in a substrate processing system includes: a resistance calculation module for calculating a first resistance of a first heater element among a plurality of heater elements of the first substrate support; a temperature calculation module for calculating a first temperature of the first heater element based on the calculated first resistance; and a filter module for filtering a first signal corresponding to the calculated first resistance. The temperature calculation module selectively causes the filter module to filter the first signal in response to determining whether at least one condition associated with the operation of the substrate processing system is met.

[0006] Among the other features, at least one condition corresponds to the operation of the substrate processing system associated with a temperature change in the first heater element. The temperature calculation module determines whether the temperature change in the first heater element is expected based on a calculated first resistance, and selectively causes the filter module to filter the first signal in response to determining that the temperature change is not expected. The temperature calculation module determines whether the rate of temperature change in the first heater element exceeds a threshold based on a calculated first resistance, and selectively causes the filter module to filter the first signal in response to determining that the rate of temperature change exceeds the threshold.

[0007] Among other features, the temperature calculation module compares a first temperature change in the first heater element with a second temperature change in the second heater element, and selectively causes the filter module to filter the first signal based on the comparison. The second heater element is located in the second substrate support. The filter module applies a resistance offset to the first signal in response to determining whether at least one condition associated with the operation of the substrate processing system is met. The controller further includes a temperature control module configured to control the power supplied to the first heater element based on the first signal.

[0008] Among other features, the resistance calculation module receives a first current corresponding to the first heater element, receives a first voltage corresponding to the first heater element, and calculates a first resistance based on the first voltage and the first current. The temperature calculation module calculates a first temperature based on the calculated first resistance and the resistance temperature coefficient of the first heater element.

[0009] The system includes: a resistance calculation module for receiving current corresponding to a heater element in a substrate support, receiving voltage corresponding to the heater element, and calculating the resistance of the heater element based on the voltage and current; a temperature calculation module for calculating the temperature of the heater element based on the calculated resistance; and a filter module for filtering the signal corresponding to the calculated resistance. The temperature calculation module selectively causes the filter module to filter the signal in response to determining whether at least one condition related to a temperature change of the heater element is met. The system further includes a temperature control module configured to control the power supplied to the heater element based on the signal filtered by the filter module.

[0010] Among other features, the temperature calculation module determines, based on the calculated first resistance, at least one of the following: whether the temperature change of the heater element is expected, and whether the rate of temperature change of the heater element exceeds a threshold. The temperature calculation module selectively causes the filter module to filter the signal in response to the determination that: the temperature change of the heater element is not expected, the rate of temperature change of the heater element exceeds a threshold, and the temperature change of the heater element is not within the range of temperature changes of another heater element.

[0011] A method for controlling the temperature of a first substrate support in a substrate processing system includes: calculating a first resistance of a first heater element among a plurality of heater elements of the first substrate support; calculating a first temperature of the first heater element based on the calculated first resistance; and selectively filtering a first signal corresponding to the calculated first resistance in response to determining whether at least one condition associated with the operation of the substrate processing system is satisfied.

[0012] Among other features, at least one condition corresponds to the operation of the substrate processing system associated with a temperature change in the first heater element. The method further includes determining whether a temperature change in the first heater element is expected based on a calculated first resistance, and selectively filtering a first signal in response to determining that the temperature change is not expected. The method further includes determining whether a rate of temperature change in the first heater element exceeds a threshold based on a calculated first resistance, and selectively filtering the first signal in response to determining that the rate of temperature change exceeds the threshold.

[0013] Among other features, the method further includes comparing a first temperature change in the first heater element with a second temperature change in the second heater element, and selectively filtering the first signal based on the comparison. The second heater element is located in the second substrate support. The method further includes controlling the power supplied to the first heater element based on the first signal.

[0014] Further applications of the disclosed content will become apparent from the embodiments, the scope of the claims, and the drawings. The detailed description and specific examples are for illustrative purposes only and are not intended to limit the scope of this disclosure.

Implementation Method

[0022] Film deposition and etching processes can vary in spatial distribution (i.e., xy coordinates of a horizontal plane). For example, in a deposition process, the properties of the deposited film vary within a spatial distribution range. Conversely, in an etching process, the amount of etching may vary within a spatial distribution range.

[0023] The properties of the etched and deposited films (e.g., deposited atomic layer deposition (ALD) films, plasma-enhanced chemical vapor deposition (PECVD) films, etc.) may be affected by the temperature of the substrate during deposition. Therefore, a temperature control system can be implemented in the substrate support (e.g., a stage comprising a flat upper surface configured to support the substrate). For example, during an ALD process (e.g., deposition of an oxide film), the substrate is placed on the stage. Typically, an ALD stage contains a single temperature-controlled region. In some instances, an ALD stage may contain multiple temperature-controlled regions (e.g., a center region, an inner region, and an outer region). A heater layer may be embedded in the upper layer of the ALD stage. The heater layer may be configured to receive voltage / current to act as a resistance heater to heat the stage and the substrate disposed thereon. The heater layer may be configured to heat a single region or multiple regions of an individual heated stage, such as an inner region and an outer region.

[0024] Typically, due to manufacturing and architectural limitations, a stage containing a single or multiple areas may contain only a single temperature sensor located in the central area of ​​the stage. In other instances, the stage may not contain any temperature sensors. Therefore, precise control of the stage temperature may be limited.

[0025] In some instances, the temperature control system may be configured to calculate the temperature of a corresponding region of the heater element and the pedestal based on the temperature coefficient of resistance (TCR), voltage, and current of each heater element. For example, the pedestal may include a heater layer containing heater elements having a high TCR (e.g., greater than or equal to 1.0%). For example, the heater elements may include, but are not limited to, molybdenum and nickel heater elements. TCR can be positive or negative. A positive TCR is associated with resistance that increases with increasing temperature. Conversely, a negative TCR is associated with resistance that decreases with increasing temperature.

[0026] Therefore, the overall resistance of the heater layer (i.e., one or more heater elements corresponding to the heater layer) indicates the temperature of the heater layer. The current supplied to the heater layer and the voltage across the heater layer can be measured to calculate the resistance of the heater layer. The corresponding temperatures of the outer and inner regions can be calculated based on the changes in the resistance of the heater layer. In this way, the temperatures of different regions of the substrate support (and therefore the substrate regions within those different regions) can be controlled independently of each other and independently of thermal loads and other system transients.

[0027] Measurement signals indicating current and voltage are used to calculate resistance. System noise and spurious changes in resistance can lead to inaccurate resistance and temperature calculations and defective temperature control. For example, system variations unrelated to temperature changes (such as component wear or other structural variations) can cause permanent or intermittent changes in resistance. Therefore, any resistance change not caused by actual temperature variations can lead to inaccurate temperature control.

[0028] The temperature control system may include one or more filters (e.g., first-order linear filters). For example, the filters may be configured to filter out noise from the measurement signal. However, the filters do not filter out resistance changes that may be caused by variations such as oxidation, component wear, loosening of fittings, connectors and joints.

[0029] The temperature control system and method according to this disclosure implement a filter system configured to distinguish between noise caused by structural variations and resistance changes. For example, the filter system implements both linear and nonlinear filters. The filter system selectively filters the measurement signal to remove noise and resistance changes caused by system variations unrelated to temperature changes, while retaining signal characteristics related to the actual temperature changes.

[0030] Referring now to FIG1, an example of a substrate processing system 100 according to the present disclosure, including a substrate support (e.g., a stage, such as an ALD or PECVD stage) 104, is shown. The substrate support 104 is disposed within a processing chamber 108. The substrate 112 is disposed on the substrate support 104 during processing.

[0031] The gas delivery system 120 includes gas sources 122-1, 122-2, ..., 122-N (collectively referred to as gas sources 122) connected to valves 124-1, 124-2, ..., 124-N (collectively referred to as valves 124) and mass flow controllers 126-1, 126-2, ..., 126-N (collectively referred to as MFC 126). MFC 126 controls the gas flow from gas sources 122 to a gas mixing manifold 128. The output of manifold 128 is supplied to manifold 136 via an optional pressure regulator 132. The output of manifold 136 is input to a multi-injector spray head 140. Although manifolds 128 and 136 are shown, a single manifold may be used.

[0032] The substrate support 104 includes a plurality of regions. As shown, the substrate support 104 includes an inner (central) region 144 and an outer region 148. The temperature of the substrate support 104 can be controlled by using one or more heating elements (e.g., resistance heaters) 160 disposed in the substrate support 104, as described in more detail below. In other embodiments, the substrate support 104 may include more (e.g., three or more) regions or only one region.

[0033] In some embodiments, the substrate support 104 may include a coolant passage 164. Cooling fluid is supplied from a fluid reservoir 168 and a pump 170 to the coolant passage 164. Pressure sensors 172 and 174 may be disposed in manifold 128 or manifold 136, respectively, to measure pressure. Valve 178 and pump 180 may be used to discharge reactants from processing chamber 108 and / or control the pressure within processing chamber 108.

[0034] Controller 182 may include a dosage controller 184 that controls the administration of the agent provided by the multi-injector spray head 140. Controller 182 also controls the gas delivery from gas delivery system 120. Controller 182 uses valve 178 and pump 180 to control the pressure in the processing chamber and / or the discharge of reactants. Controller 182 controls the temperature of substrate support 104 and substrate 112 based on temperature feedback (e.g., from sensors (not shown) in the substrate support and / or sensors (not shown) that measure the coolant temperature).

[0035] One or more signals supplied to the substrate support 104 (e.g., between the substrate support 104 and the controller 182) are directed through the filter box 188. For example, the measurement signal 192 may indicate the corresponding voltage and current of the heater element 160. The controller 182 is configured to calculate the temperature of the heater element 160 and the corresponding area of ​​the substrate support 104 based in part on the measurement signal 192, and based on the TCR, voltage, and current of each of the heater elements 160. The controller 182 according to this disclosure is further configured to selectively filter the resistance value calculated using the measurement signal 192, as described in more detail below.

[0036] Referring now to Figures 2A and 2B, a simplified illustration of a substrate support 200 according to the present disclosure is shown schematically and in plan view, respectively. The substrate support 200 includes a conductive substrate 204 and a heater layer 208. For example, the heater layer 208 may be formed on the upper surface 212 of the substrate 204. The substrate 204 is disposed within an upper plate (e.g., an aluminum diffuser plate) 216. Thus, the heater layer 208 is embedded within the substrate support 200. A substrate 220 may be disposed on the substrate support 200 for processing (e.g., for ALD or PECVD processing).

[0037] As shown in the figure, the substrate support 200 (and the corresponding heater layer 208) comprises two regions: an inner (center) region 224-1 and an outer region 224-2, collectively referred to as region 224. The inner region 224-1 and the outer region 224-2 contain corresponding resistance heater elements 228-1 and 228-2, collectively referred to as heater elements 228. For example only, heater elements 228 are made of a material having a positive or negative TCR greater than 1.0%, such as molybdenum, nickel, tungsten, etc. Heater elements 228-1 and 228-2 may be individually controllable. For example, heater elements 228 may receive power (e.g., current) in response to commands from a controller 232, which may correspond to controller 182 of Figure 1. In other instances, the substrate support 200 may correspond to only a single controllable region and heater element. In some instances, the substrate support 200 may include a temperature sensor 236 located at the center (i.e., in the inner region 224-1). The controller 232 is configured to calculate the resistance of the heater elements 228-1 and 228-2 based on measured currents and voltages associated with the heater elements 228-1 and 228-2, and to calculate and control the corresponding temperatures in regions 224-1 and 224-2 based on the calculated resistances, as described in more detail below.

[0038] Measurement signals 240 indicating the current and voltage of the heater element 228 are provided to the controller 232. For example, the measurement signal 240 may include raw voltage and current measurements. The controller 232 uses the voltage and current measurements to calculate the resistance (i.e., resistance value) of the heater element 228. A filter box 244 can filter out noise from the measurement signal 240. For example, the filter box 244 may implement a linear filter configured to filter out system noise (e.g., periodic or high-frequency noise) from the measurement signal 240. The controller 232 according to this disclosure includes a filter module configured to selectively filter the calculated resistance value.

[0039] Referring now to FIG3, an exemplary controller 300 configured to calculate and control the temperature in regions 224-1 and 224-2 is shown. The controller 300 receives signals, including, but not limited to, a voltage signal 304-1 and a current signal 304-2 collectively referred to as signal 304. Voltage signal 304-1 may contain a signal indicating a corresponding voltage of the heater element 228 in region 224. Current signal 304-2 may contain a signal indicating a corresponding current through the heater element 228. For example, voltage signal 304-1 and current signal 304-2 may correspond to analog measurement signals provided from individual sensors 308 via filter box 244 (not shown in FIG3).

[0040] The analog-to-digital (A / D) converter 312 converts the voltage signal 304-1 and the current signal 304-2 into a digital signal 316. Although shown as a single A / D converter 312, the controller 300 may implement different A / D converters for each of the signals 304. The resistance calculation module 320 is configured to calculate the resistance value of each of the heater elements 228 based on the digital signal 316. For example, the resistance calculation module 320 may calculate the resistance based on the indicated voltage and current according to Ohm's law and output a signal 324 indicating the calculated resistance. In some instances, the resistance calculation module 320 may perform gain correction and / or apply an offset to the digital signal 316 before calculating the resistance. In some instances, the resistance calculation module 320 may calculate the power output of each of the heater elements 228 based on the indicated voltage and current (e.g., by multiplying the voltage and current of each of the heater elements 228) and output a signal 328 indicating the calculated power value.

[0041] According to this disclosure, the temperature calculation module 332 receives the calculated resistance of each of the heater elements 228 and calculates the temperature in the corresponding regions 224-1 and 224-2 based on the calculated resistance. For example, as described above, the material of the heater element 228 has a known TCR, which represents the change in resistance in response to a change in temperature. Therefore, for a given heater element 228 and material, the temperature calculation module 332 is configured to calculate the temperature change in the corresponding region 224 based on the change in resistance.

[0042] For example, the temperature of region 224 can be correlated with the resistance of heater element 228 according to a curve / slope defined by T = TCR * R - TC (Equation 1), where T is the temperature of region 224, R is the calculated resistance of heater element 228, TCR is a TCR correction factor (e.g., °C / ohm), and TC is a temperature constant offset (e.g., 230°C). For example, for molybdenum, the temperature of the heater element can be calculated according to T = (46°C / ohm) * R – 230°C. Temperature calculation module 332 stores data indicating the correlation between the temperature of region 224 and the resistance of heater element 228. In one example, temperature calculation module 232 stores a resistance-to-temperature (R / T) conversion table that indexes the possible measured resistance range of heater element 228 to the corresponding temperature of region 224 (e.g., in 1°C intervals) according to the curve defined by Equation 1. In other instances, the temperature calculation module 332 can store and execute models, equations, etc., based on the calculated resistance calculation region 224. The temperature calculation module 332 outputs the corresponding temperatures of regions 224-1 and 224-2 based on the calculated resistance and R / T conversion table.

[0043] The temperature calculation module 332 can generate an R / T conversion table during initial calibration (e.g., during the manufacturing, assembly, and maintenance of the processing chamber 108, or during the installation and / or maintenance of the substrate support 200). For example, during calibration, the resistance of the heater element 228 can be calculated when the temperature in region 224 is measured using one or more temporary temperature sensors (e.g., sensors for temperature-sensing test substrates mounted on the substrate support 200).

[0044] The temperature calculation module 332 according to this disclosure includes a filter module 334 configured to selectively filter the calculated resistance value and / or the calculated temperature. In other words, the filter module 334, as described below, can selectively filter the calculated resistance value before it is converted into a calculated temperature, or can filter the calculated temperature after it has been converted from the calculated resistance value. For illustrative purposes, the filter module 334 will be described as operating based on the calculated resistance value before it is converted into a calculated temperature.

[0045] The temperature calculation module 332 is configured to selectively apply the filter module 334 to the calculated resistance value (i.e., signal 324) depending on whether one or more conditions are met. In other words, if one or more conditions are not met, the temperature calculation module 332 converts the calculated resistance value indicated by signal 324 into a temperature as described above. Conversely, if one or more conditions are met, the filter module 334 filters the signal before converting it into the calculated temperature.

[0046] For example, the temperature calculation module 332 may receive one or more signals 340 indicating individual conditions in the substrate processing system 100 that may affect resistance and temperature measurements. For example, the signals 340 may indicate various operating parameters of the substrate processing system 100, such as whether the substrate is on the substrate support 200, which process step is being performed, process parameters (e.g., process or purge gas flow, pressure changes, plasma activation, RF power changes, etc.), and movement of components of the substrate support 200. The temperature calculation module 332 may compare the information indicated by the signals 340 with stored data (e.g., rule sets) to determine whether one or more conditions are met.

[0047] The filter module 334 can implement linear and / or nonlinear filtering and is configured to selectively apply an offset (i.e., a resistance value offset) to the signal 324, perform median filtering, Kalman filtering, etc. More specifically, the filter module 334 is configured to selectively filter the signal 324 based on whether the change in the resistance value indicated by the signal 324 satisfies one or more conditions.

[0048] As described above, a change in resistance value typically represents a corresponding change in temperature. However, systemic variations unrelated to temperature changes can also cause changes in the calculated resistance value, such as those caused by component wear, oxidation, loose fittings, connections, wiring, and connectors. These systemic variations may occur and increase in magnitude during the lifespan of the substrate support 200. Therefore, the temperature calculation module 332 is configured to determine whether the resistance change is caused by an actual temperature change or by permanent or intermittent systemic variations. For example only, the temperature calculation module 332 determines whether a change in resistance in a given area is expected based on the expected temperature change, the expected rate of temperature change, and a comparison with temperature changes in other areas and / or processing stations. The filter module 334 applies a filter to the calculated resistance value based on the determination made by the temperature calculation module 332, as described in more detail below in Figure 4.

[0049] The temperature control module 344 receives a signal 346 indicating the calculated temperature and controls the heater element 228 accordingly. In other words, the signal 346 corresponds to either (i) the temperature calculated using the unfiltered signal 324, or (ii) the temperature calculated using the signal 324 filtered by the filter module 334 as described above. The temperature control module 344 is configured to output a power control signal 348 to adjust the power (e.g., current) supplied to the heater element 228 based on the calculated temperature. In this way, the controller 300 is configured to implement closed-loop control of the temperature of region 224.

[0050] The temperature control module 344 may be further configured to receive an output signal 328 indicating a calculated power value, and compare the calculated power value with the command power indicated by the power control signal 348. In some instances, the difference between the command power and the calculated power may indicate one or more faults, including but not limited to wiring faults (e.g., open or reverse wiring, wiring short circuit, etc.). The controller 300 may be configured to indicate the fault to the user (e.g., via the user interface / display 352 of the controller 300).

[0051] Similarly, the temperature calculation module 332 may be configured to determine and / or indicate faults associated with: the difference between the calculated temperature and the sensed temperature (e.g., from the temperature sensor 340), the difference between the corresponding calculated temperatures in region 224 (e.g., a difference greater than a threshold), the difference between the calculated temperature and the desired temperature (e.g., controlled via signal 348), etc. For example, these differences may further indicate wiring or other faults, such as damaged components of the substrate support 200.

[0052] Referring now to FIG4, an exemplary method 400 for selectively filtering a signal corresponding to a calculated resistance in a substrate support, according to the present disclosure, is shown. For example, method 400 is implemented at least in part by a temperature calculation module 332. At 404, method 400 generates and stores data (e.g., in the memory of controller 300) defining one or more conditions for filtering signal 324 using a filter module. For example, the data may include a truth table identifying one or more conditions for filtering signal 324. In one example, these conditions correspond to the determination of whether a change in resistance is expected due to a anticipated change in temperature, whether the rate of temperature change is expected (i.e., within a defined range), and whether other areas and / or processing stations are experiencing similar temperature changes. Temperature calculation module 332 determines whether to filter signal 324 based on the truth table.

[0053] At 408, method 400 receives one or more signals indicating the calculated resistance of a heater element in a given sampling period. Although temperature calculation module 332 receives signals corresponding to multiple heater elements in each sampling period, method 400 will be described for a single heater element. At 412, method 400 (e.g., temperature calculation module 332) determines whether the calculated resistance indicates a change in temperature. For example, temperature calculation module 332 compares the calculated resistance with a previously calculated resistance (e.g., calculated in a previous sampling period). If yes, method 400 proceeds to 416. If no, method 400 proceeds to 408.

[0054] At 416, method 400 (e.g., temperature calculation module 332) determines whether the temperature change of the corresponding heater element is expected. For example, temperature changes can be expected during various operations related to substrate processing, including but not limited to: transfer of the substrate to and from the substrate support 200, start or interruption of various process steps (e.g., process or purge gas flow, pressure changes, plasma activation, RF power changes, etc.), and movement of components of the substrate support 200. Method 400 determines whether the temperature change is expected based in part on signals 340 indicating various operating parameters of the aforementioned substrate processing system 100. If yes, method 400 continues to 420. If no, method 400 continues to 424.

[0055] At 420, method 400 (e.g., temperature calculation module 332) processes signal 324 without additional filtering from filter module 334. For example, method 400 calculates the temperature of the heater element, provides signal 346 to temperature control module 344, and controls the temperature of the heater element accordingly. An illustrative method for controlling temperature is described in more detail in U.S. Patent No. 10 / 633,742, published April 28, 2020, the entire contents of which are incorporated herein by reference.

[0056] At 424, method 400 (e.g., temperature calculation module 332) determines whether the rate of change of temperature indicated by the calculated resistance is expected. For example, temperature calculation module 332 compares the rate of change of temperature with one or more thresholds (e.g., thresholds defined in stored data). The thresholds may correspond to a temperature rate of change limit associated with the corresponding application or processing step. The temperature rate of change limit may be selected based on the maximum rate of change expected during the execution of the processing step. If yes, method 400 continues to 420. If no, method 400 continues to 428.

[0057] At 428, method 400 (e.g., temperature calculation module 332) determines whether the temperature change indicated by the calculated resistance (e.g., change in magnitude and / or rate of change) is similar to the temperature change calculated for other heater elements and / or processing stations. As described above, temperature calculation module 332 receives signals 324 from a plurality of heater elements corresponding to different regions of the same substrate support 200, and may also receive signals 324 from heater elements corresponding to additional substrate supports in different processing chambers or stations. Therefore, method 400 determines whether other heater elements or substrate supports are experiencing a change similar to the temperature change corresponding to the calculated resistance (e.g., change in magnitude or rate of change within, for example, 10%). If yes, method 400 continues to 420. If no, method 400 continues to 432.

[0058] At 432, method 400 (e.g., temperature calculation module 332) applies additional filtering to signal 324. For example, temperature calculation module 332 uses filter module 334 to filter signal 324. In other words, if the temperature change is not expected, the rate of temperature change exceeds the limit associated with the process step being performed, and the heater elements in other areas and / or the substrate support do not experience similar temperature changes, then temperature calculation module 332 can determine that the calculated change in resistance is not caused by the actual temperature change. Instead, the calculated change in resistance may have been caused by system variations, such as the aforementioned oxidation, component wear, loosening of fittings, connections, and joints. Therefore, filter module 334 filters signal 324 to compensate for system variations (e.g., by applying an offset), and method 400 continues to 436.

[0059] At 436, method 400 (e.g., temperature calculation module 332) processes signal 324 after additional filtering applied by filter module 334. For example, method 400 uses the filtered signal 324 to calculate the temperature of the heater element, provides signal 346 to temperature control module 344, and controls the temperature of the heater element accordingly.

[0060] The foregoing description is illustrative in nature and is not intended to limit the scope of this disclosure, its application, or its uses. The broad teachings of this disclosure can be implemented in various forms. Therefore, while this disclosure contains specific examples, its true scope should not be so limited, as other modifications will become apparent upon reading the drawings, specification, and appended claims. It should be understood that one or more steps within the method may be performed in different orders (or simultaneously) without altering the principles of this disclosure. Furthermore, although each of the embodiments is described above as having certain features, any one or more of those features described with respect to any embodiment of this disclosure may be implemented in features of any other embodiment and / or combined with features of any other embodiment, even if such combination is not explicitly described. In other words, the embodiments are not mutually exclusive, and substitutions of one or more embodiments with each other remain within the scope of this disclosure.

[0061] Spatial and functional relationships between components (e.g., between modules, circuit elements, semiconductor layers, etc.) are described using a variety of terms, including “connection,” “joint,” “coupled,” “adjacent,” “next to,” “above,” “under,” and “set.” When describing the relationship between a first and a second component in the foregoing disclosure, unless explicitly described as “direct,” the relationship may be a direct relationship in which there are no other intermediate components between the first and second components, or it may be an indirect relationship in which there are one or more intermediate components (spatially or functionally) between the first and second components. As used herein, at least one of the terms A, B, and C shall be interpreted as meaning the logic of using non-exclusive OR (A OR B OR C), and shall not be interpreted as meaning “at least one of A, at least one of B, and at least one of C.”

[0062] In some embodiments, the controller is part of a system that may be part of the examples described above. Such a system may include semiconductor processing equipment, including one or more processing tools, one or more chambers, one or more processing platforms, and / or specific processing components (wafer pedestals, gas flow systems, etc.). These systems may be integrated with electronic components for controlling their operation before, during, and after the processing of semiconductor wafers or substrates. These electronic components may be referred to as "controllers," which control the main components or sub-components of one or more systems. Depending on the processing requirements and / or the type of system, the controller may be programmed to control any of the processes disclosed herein, including the delivery of processing 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 rate settings, fluid delivery settings, position and operation settings, wafer transfer tools and other transfer tools, and / or loading locks connected to or interfacing with a specific system.

[0063] Broadly speaking, a controller can be defined as an electronic component having numerous integrated circuits, logic, memory, and / or software that receives instructions, issues instructions, controls operations, enables cleaning operations, enables endpoint measurements, etc. Integrated circuits may include chips in the form of firmware storing 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 numerous individual settings (or program files), defining operating parameters for performing specific processes on or for a semiconductor wafer or for a system. In some embodiments, operating parameters may be part of a recipe defined by a process engineer to complete one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or wafer dies.

[0064] In some embodiments, the controller may be part of or coupled to a computer that is integrated with, coupled to, or otherwise networked to the system, or a combination thereof. For example, the controller may be in the "cloud" or in all or part of a wafer fab host system, allowing remote access to wafer processing. The computer may enable remote access to the system to monitor the current progress of manufacturing operations, examine the history of past manufacturing operations, examine trends or performance metrics from multiple manufacturing operations, change parameters of the current process, set processing steps to follow the current process, or start a new process. In some instances, the remote computer (e.g., a server) may provide process recipes to the system via a network, which may include a local area network or the Internet. The remote computer may include an input or programmed user interface for implementing parameters and / or settings, which are then communicated from the remote computer to the system. In some instances, the controller receives instructions in the form of data specifying parameters for each of the processing steps to be performed during one or more operations. It should be understood that parameters can be specific to the type of process to be performed and the type of tool to which the controller is configured to interface with or control. Therefore, as described above, the controller can be distributed, for example, by comprising one or more discrete controllers networked together and operating for a common purpose (such as the processes and control described herein). An example of a distributed controller for such a purpose would be one or more integrated circuits on a chamber that communicate with one or more integrated circuits located remotely (e.g., at the platform level or as part of a remote computer), which together control the process on the chamber.

[0065] Without limitation, the illustrated system may include a plasma etching chamber or module, a deposition chamber or module, a spin wash chamber or module, a metal plating chamber or module, a cleaning chamber or module, a bevel etching chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etching (ALE) chamber or module, an ion implantation chamber or module, an orbital chamber or module, and any other semiconductor processing system that may be associated with or used in the manufacture and / or fabrication of semiconductor wafers.

[0066] As described above, depending on one or more process steps to be performed by the tool, the controller may communicate with one or more of the following: other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located at various locations in the plant, host computer, another controller, or tools used for material transport and to transport wafer containers to and from tool locations and / or loading ports in the semiconductor manufacturing plant. [Simplified Explanation of the Diagram]

[0015] This disclosure will become more fully understood from the detailed description and accompanying drawings, wherein:

[0016] Figure 1 is a functional block diagram of an exemplary substrate processing system according to the present disclosure;

[0017] FIG2A is an example of a substrate support according to the present disclosure;

[0018] FIG2B is a plan view of an exemplary substrate support according to the present disclosure;

[0019] Figure 3 is a functional block diagram of an illustrative controller according to this disclosure; and

[0020] Figure 4 shows the steps of an exemplary method for selectively filtering a signal corresponding to a calculated resistance in a substrate support according to the present disclosure.

[0021] Reference numbers may be used repeatedly in the drawings to indicate similar and / or identical elements.

Claims

1. A controller for controlling the temperature of a first substrate support in a substrate processing system, the controller comprising: a resistance calculation module for calculating a first resistance of one of a plurality of heater elements of the first substrate support; a temperature calculation module for calculating a first temperature of the first heater element based on the calculated first resistance; and a filter module for filtering a first signal corresponding to the calculated first resistance, wherein the temperature calculation module selectively causes the filter module to filter the first signal in response to a determination of whether at least one condition associated with the operation of the substrate processing system is satisfied.

2. The controller of claim 1, wherein the at least one condition corresponds to one operation of the substrate processing system associated with a temperature change in one of the first heater elements.

3. The controller of claim 1, wherein the temperature calculation module determines whether a temperature change in the first heater element is expected based on the calculated first resistance, and selectively causes the filter module to filter the first signal in response to determining that the temperature change is not expected.

4. The controller of claim 1, wherein the temperature calculation module determines whether a temperature change rate in the first heater element exceeds a threshold based on the calculated first resistance, and in response to determining that the temperature change rate exceeds the threshold, selectively causes the filter module to filter the first signal.

5. The controller of claim 1, wherein the temperature calculation module compares a first temperature change in one of the first heater elements with a second temperature change in one of the second heater elements, and selectively causes the filter module to filter the first signal based on the comparison.

6. The controller of claim 5, wherein the second heater element is located in a second substrate support.

7. The controller of claim 1, wherein the filter module applies a resistance offset to the first signal in response to determining whether at least one condition associated with the operation of the substrate processing system is met.

8. The controller of claim 1 further includes a temperature control module configured to control the power supplied to the first heater element based on the first signal.

9. The controller of claim 1, wherein the resistance calculation module receives a first current corresponding to the first heater element, receives a first voltage corresponding to the first heater element, and calculates the first resistance based on the first voltage and the first current.

10. The controller of claim 9, wherein the temperature calculation module calculates the first temperature based on the calculated first resistor and a resistance temperature coefficient of the first heater element.

11. A temperature control system comprising: a resistance calculation module for receiving a current corresponding to a heater element in a substrate support, receiving a voltage corresponding to the heater element, and calculating a resistance of the heater element based on the voltage and the current; a temperature calculation module for calculating a temperature of the heater element based on the calculated resistance; a filter module for filtering a signal corresponding to the calculated resistance, wherein the temperature calculation module selectively filters the signal in response to determining whether at least one condition associated with a change in the temperature of the heater element is satisfied; and a temperature control module configured to control the power supplied to the heater element based on the signal filtered by the filter module.

12. The temperature control system of claim 11, wherein the temperature calculation module determines, based on the calculated resistance, at least one of the following: (i) whether the change in temperature of the heater element is expected, and (ii) whether the rate of change in temperature of the heater element exceeds a threshold.

13. The temperature control system of claim 11, wherein the temperature calculation module selectively causes the filter module to filter the signal in response to the determination that: the change in the temperature of the heater element is not expected, the rate of change in the temperature of the heater element exceeds a threshold, and the change in the temperature of the heater element is not within the range of the temperature change of another heater element.

14. A method for temperature control to control the temperature of a first substrate support in a substrate processing system, the method comprising: calculating a first resistance of a first heater element among a plurality of heater elements of the first substrate support; calculating a first temperature of the first heater element based on the calculated first resistance; and selectively filtering a first signal corresponding to the calculated first resistance in response to determining whether at least one condition associated with operation of the substrate processing system is satisfied.

15. The method of claim 14, wherein the at least one condition corresponds to one operation of the substrate processing system associated with a temperature change in one of the first heater elements.

16. The method of claim 14 further includes determining, based on the calculated first resistance, whether a temperature change in one of the first heater elements is expected, and selectively filtering the first signal in response to determining that the temperature change is not expected.

17. The method of claim 14 further includes determining, based on the calculated first resistance, whether a temperature change rate in the first heater element exceeds a threshold, and selectively filtering the first signal in response to determining that the temperature change rate exceeds the threshold.

18. The method of claim 14 further comprises comparing a first temperature change in the first heater element with a second temperature change in a second heater element, and selectively filtering the first signal based on the comparison.

19. The method of claim 18, wherein the second heater element is located in a second substrate support.

20. The method of claim 14 further includes controlling the power supplied to the first heater element based on the first signal.

Images