Automatic calibration process independent feed-forward control

Abstract

The present invention relates to automatically calibrated process independent feedforward control. A substrate processing system for processing a substrate includes a sensor for generating a sensed value of a parameter of the substrate processing system. An actuator adjusts the parameter of the substrate processing system. A controller communicates with the sensor and the actuator and is configured to: process a first substrate during a process without feedforward control by using the sensed value to adjust a control value for controlling the actuator. The sensed value is delayed and causes instability in the parameter. The controller is also configured to automatically calibrate a feedforward value for processing a second substrate based on the sensed value and the control value; and process the second substrate while controlling the actuator using the feedforward value.

Description

Technical Field

[0001] The present disclosure relates to substrate processing systems, and more particularly to a feedforward control system for automatic calibration of substrate processing systems. Background Art

[0002] The background description provided here is for the purpose of generally presenting the context of the present disclosure. Work by the presently designated inventors to the extent described in this background section and in aspects of the description that could not be determined as prior art at the time of filing the application is neither explicitly nor implicitly admitted to be prior art against the present disclosure.

[0003] Substrate processing systems can be used to perform etching, deposition, cleaning, and / or other processing on substrates such as semiconductor wafers. During processing, the substrate is arranged on a substrate support, such as a pedestal, an electrostatic chuck (ESC), etc., in a processing chamber of the substrate processing system. A process gas mixture is introduced into the processing chamber to process the substrate. In some examples, a plasma can be excited to enhance chemical reactions within the processing chamber. An RF bias can be provided to the substrate support to control ion energy.

[0004] A controller for running the process can receive feedback values ​​related to chamber parameters from one or more sensors. For example, the controller can receive feedback values ​​from one or more temperature or pressure sensors. The controller adjusts the process according to a recipe and controls an actuator according to the feedback values ​​from the sensors. Examples of actuators include heaters, valves, RF generators, pumps, etc. In some examples, the feedback values ​​provided by the sensors can be delayed. As a result, the controller cannot adjust the actuator in time to avoid deviation from the desired operating state.

[0005] Although feedforward control can be used, it can be difficult to implement. The feedforward values ​​for each process step and for each process are manually determined and tested. For example, the feedforward values ​​for each new or modified recipe may require days of work to determine.

[0006] Alternatively, higher cost sensors can be used to sense chamber parameters in real time. For example, optical sensors can be used to measure susceptor temperature without delay. However, optical sensors and their supporting electronics are expensive. Furthermore, if optical sensors are used, temperature sensors are also typically required for redundancy. Summary of the invention

[0007] A substrate processing system for processing a substrate includes a sensor for generating a sensed value of a parameter of the substrate processing system. An actuator adjusts the parameter of the substrate processing system. A controller communicates with the sensor and the actuator and is configured to: process a first substrate during a process without feedforward control by using the sensed value to adjust a control value for controlling the actuator. The sensed value is delayed and causes instability in the parameter. The controller is also configured to automatically calibrate a feedforward value for processing a second substrate based on the sensed value and the control value; and process the second substrate while controlling the actuator using the feedforward value.

[0008] In other features, in order to automatically calibrate the feed-forward values, the controller is further configured to: time-shift the sensed values ​​by a delay period to produce time-shifted sensed values; determine changes in the time-shifted sensed values ​​during multiple steps of the process; determine durations of the multiple steps of the process; determine feed-forward values ​​for multiple steps of the process based on the control value for the actuator, the changes in the sensed values ​​during a corresponding one of the multiple steps, and the duration of the corresponding one of the multiple steps of the process; and process the second substrate based on the feed-forward values.

[0009] In other features, the delay period is longer than 5 seconds. The controller is further configured to perform data smoothing on the sensed values ​​from the sensor. The controller is further configured to perform interpolation to match timestamps of the sensed values ​​and the control values. The controller is further configured to determine an average value of the control value during the multiple steps of the process. The controller is further configured to determine the feedforward values ​​for the multiple steps of the process based on the average value, the change in the sensed values ​​during the multiple steps of the process, and the duration of the multiple steps of the process.

[0010] Among other features, based on DC avg -FF_Constant*(ΔT / ΔS) calculates the feedforward value for the second substrate, where DC avg corresponds to the average value, ΔT corresponds to the change in the sensed value during the plurality of steps of the process, ΔS corresponds to the duration of the plurality of steps of the process, and FF_Constant corresponds to a scaling factor. avg -FF_Constant / K*(ΔT / ΔS) calculates the feedforward value for the third substrate, where DCavg corresponds to the average value, ΔT corresponds to the variation of the sensed values ​​during the plurality of steps of the process, ΔS corresponds to the duration of the plurality of steps of the process, FF_Constant corresponds to a scaling factor, and K is a calibration reduction factor.

[0011] In other features, the sensor comprises a temperature sensor. The actuator comprises a heater for a substrate support of the substrate processing system. The control value comprises a duty cycle value. The substrate processing system performs at least one of deposition and etching.

[0012] A method for processing a substrate in a substrate processing system includes: generating a sensed value of a parameter of the substrate processing system; adjusting the parameter of the substrate processing system; processing a first substrate during a process without feedforward control by using the sensed value to adjust a control value for controlling an actuator. The sensed value is delayed and causes instability in the parameter. The method also includes automatically calibrating a feedforward value for processing a second substrate based on the sensed value and the control value; and processing the second substrate while controlling the actuator using the feedforward value.

[0013] In other features, automatically calibrating the feed-forward value includes: time-shifting the sensed value by a delay period to produce a time-shifted sensed value; determining a change in the time-shifted sensed value during multiple steps of the process; determining a duration of the multiple steps of the process; determining feed-forward values ​​for multiple steps of the process based on the control value for the actuator, the change in the sensed value during a corresponding one of the multiple steps, and the duration of the corresponding one of the multiple steps of the process; and processing the second substrate based on the feed-forward value.

[0014] In other features, the method includes performing data smoothing on the sensed values ​​from the sensor. The method includes performing interpolation to match time stamps of the sensed values ​​and the control values. The method includes determining an average value of the control values ​​during the plurality of steps of the process.

[0015] In other features, the method includes determining the feedforward values ​​for the plurality of steps of the process based on the average value, the change in the sensed values ​​during the plurality of steps of the process, and the duration of the plurality of steps of the process. avg -FF_Constant*(ΔT / ΔS) calculates the feedforward value for the second substrate, where DC avgcorresponds to the average value, ΔT corresponds to the variation of the sensed values ​​during the plurality of steps of the process, ΔS corresponds to the duration of the plurality of steps of the process, and FF_Constant corresponds to a scaling factor.

[0016] In other features, the control value comprises a duty cycle value.The method includes performing at least one of etching and deposition using the substrate processing system.

[0017] Further areas of applicability of the present disclosure will become apparent from the detailed description, claims and drawings.The detailed description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The present disclosure will be more fully understood from the detailed description and accompanying drawings, in which:

[0019] Figure 1 is a cross-sectional view of a portion of a substrate processing system according to the present disclosure.

[0020] Figure 2 is a functional block diagram of an example of a feedforward control system for sensors and actuators according to the present disclosure;

[0021] Figure 3 is a functional block diagram of an example of a feedforward control system for a temperature sensor and a heater according to the present disclosure;

[0022] Figure 4 is a flow chart of an example of a method for providing feedforward control according to the present disclosure;

[0023] Figure 5 is a graph showing an example of temperature and duty cycle of a substrate support as a function of time according to the prior art;

[0024] Figure 6 is a graph showing an example of temperature and duty cycle of a substrate support as a function of time according to the present disclosure;

[0025] Figure 7 is a flow chart of an example of a method for determining a feedforward value according to the present disclosure; and

[0026] Figure 8 is a flow chart of an example of a method for locking a feed-forward value according to the present disclosure.

[0027] In the drawings, reference numerals may be repeated to identify similar and / or identical elements. DETAILED DESCRIPTION

[0028] Substrate processing systems use sensors to measure chamber parameters such as temperature, pressure, flow rate, or other values. In some cases, the sensed values ​​generated by the sensors may be significantly delayed relative to real time. Instabilities may occur depending on the size of the disturbance and the length of the delay.

[0029] For example, the temperature sensor used in the bevel etcher may have a long thermal delay, resulting in thermal instability. For example, instability may occur in some systems when the delay is greater than 5, 10, 15 or 20 seconds. For example, some systems such as the bevel etcher described herein have a thermal delay of about 50-55 seconds.

[0030] Feedforward control techniques can be used in systems with long feedback delays. For example, feedforward control can be used to input thermal energy into the system to counteract a cooling disturbance when it occurs and before cooling can be measured. However, implementing feedforward control can be very complex because models of all disturbances are required. This in turn requires testing to determine the feedforward value for each step of the recipe. Changes to the recipe require retesting. As a result, feedforward control is often not well received by customers.

[0031] In some processes, pressure may be increased during one or more steps of a recipe. The increase in pressure causes the susceptor and substrate to cool. Due to thermal delays, the temperature sensor may not sense the cooling quickly enough to compensate by heating the substrate support, and temperature instability occurs. Systems and methods according to the present disclosure automate the process of determining feed-forward values ​​for actuators in substrate processing systems. As a result, control of the actuator may be adjusted by an experimentally determined amount while maintaining closed-loop proportional, integral, derivative (PID) control. By the time the temperature sensor detects the change, the disturbance in the chamber parameters is very small because compensation has already been made when the disturbance occurs.

[0032] The system and method according to the present disclosure automatically selects feedforward values ​​for each step of the process after one iteration of the process without modeling or testing. The system and method continues to improve the feedforward values ​​until the desired level of control is achieved.

[0033] Although the foregoing description provides specific details related to the temperature control of the heater in the substrate support of the bevel etcher, the principles described herein can also be used to control other types of actuators in a feedforward manner. In addition, the principles described herein can be used for other types of substrate processing systems that perform chemical vapor deposition (CVD), atomic layer deposition (ALD) or other types of substrate processing.

[0034] Reference now Figure 1, a substrate processing system 100 for cleaning the bevel edge of a substrate 118 and / or depositing a thin film on the bevel edge of a substrate 118 is shown. The substrate processing system 100 includes a chamber wall 102 having a gate 142 through which the substrate 118 is loaded / unloaded. An upper electrode assembly 104 is connected to a support 108. The substrate processing system 100 includes a lower electrode assembly 106. A drive system (not shown) is attached to the support 108 for moving the upper electrode assembly 104 up and down (in the direction of the double arrow) to adjust the gap between the upper electrode assembly 104 and the substrate 118.

[0035] The metal bellows 148 form a vacuum seal between the chamber wall 102 and the support 108 while enabling the support 108 to move vertically relative to the chamber wall 102. The support 108 has a center gas feed mechanism (channel) 112 and an edge gas feed mechanism (channel) 120. One or both of the gas feed mechanisms 112, 120 can deliver a plasma gas mixture to clean the bevel edge and / or deposit a thin film on the bevel edge.

[0036] During operation, plasma is formed around the bevel edge of the substrate 118 and is generally annular. To prevent the plasma from reaching the central portion of the substrate 118, the space between the dielectric plate 116 on the upper electrode assembly 104 and the substrate 118 is small, and the process gas is supplied from a central feed mechanism. The gas then passes through the gap between the upper electrode assembly 104 and the substrate 118 in the radial direction of the substrate.

[0037] In some examples, the sweep gas is injected through the center gas feed mechanism 112, and the process gas is injected through the edge gas feed mechanism 120. The plasma / process gas is exhausted from the chamber space 151 to the bottom space 140 through a plurality of holes (outlets) 141. In some examples, a vacuum pump 143 can be used to evacuate the bottom space 140 during the cleaning operation.

[0038] The upper electrode assembly 104 includes an upper dielectric plate 116 and an upper metal component 110, which is fixed to the support 108 by a suitable fastening mechanism and grounded via the support 108. The upper metal component 110 has one or more edge gas channels or through holes 122a, 122b and an edge gas plenum 124a. The edge gas channels or through holes 122a, 122b are coupled to the edge gas feed mechanism 120 for fluid communication during operation. The upper dielectric plate 116 is attached to the upper metal component 110.

[0039] The lower electrode assembly 106 includes a powered electrode 126 having an upper portion 126a and a lower portion 126b. The pin operating unit 132 and the lifting pins 130 move the substrate 118 up and down. The bottom dielectric ring 138 includes an upper portion 138a and a lower portion 138b. In some examples, the chuck includes an electrostatic chuck or a vacuum chuck. Hereinafter, the term "powered electrode" refers to one or both of the upper portion 126a and the lower portion 126b. Similarly, the term bottom dielectric ring 138 refers to one or both of the upper portion 138a and the lower portion 138b. The powered electrode 126 is coupled to a radio frequency (RF) power source 170 to receive RF power during operation.

[0040] The lift pins 130 move vertically within the cylindrical bore or path 131 and are moved between upper and lower positions by a pin operating unit 132 located in the powered electrode 126. The pin operating unit 132 includes a housing surrounding each lift pin to maintain a vacuum-tight environment around the pin. The pin operating unit 132 includes any suitable lift pin mechanism, such as a manipulator 133 (e.g., a horizontal arm having a section extending into each housing and attached to each pin), and an arm actuator (not shown) and a pin guide assembly 133a.

[0041] The substrate 118 is mounted on a lower electrode or lower configurable plasma exclusion zone (PEZ) ring 160. The term PEZ refers to the radial distance from the center of the substrate to the outer edge of the region from which plasma used to clean the bevel edge will be excluded. In one embodiment, the top surface of the powered electrode 126, the bottom surface of the substrate 118, and the inner periphery of the lower configurable PEZ ring 160 can form a closed vacuum region recess (vacuum region) 119 in fluid communication with a vacuum source (e.g., vacuum pump 136). The cylindrical hole or path for the lift pins 130 is also shared as a gas channel through which the vacuum pump 136 evacuates the vacuum region 119 during operation. The powered electrode 126 includes a plenum 134 to reduce transient pressure fluctuations in the vacuum region 119. In the case of using multiple lift pins, the plenum 134 provides a uniform pumping rate for the cylindrical hole.

[0042] During operation, substrate warpage can be reduced by using the pressure difference between the top and bottom surfaces of the substrate 118. The pressure in the vacuum region 119 is maintained under vacuum during operation by a vacuum pump 136 coupled to the gas filling cavity 134. By adjusting the gap between the top surface of the substrate 118 and the upper dielectric plate 116, the gas pressure in the gap can be changed without changing the overall flow rate of the process gas. Therefore, by controlling the gas pressure in the gap, the pressure difference between the top and bottom surfaces of the substrate 118 can be changed, and thus the bending force applied to the substrate 118 can be controlled.

[0043] In some examples, the lower portion 138b of the bottom dielectric ring has a step 152 formed on the inner periphery of its upper surface to mate with the recess on the lower edge of the powered electrode 126. In some examples, the lower portion 138b has a step 150 formed on its outer periphery to mate with the stepped surface on the upper portion 138a of the bottom dielectric ring (referred to as the focus ring). The steps 150, 152 align the bottom dielectric ring 138 with the powered electrode 126. The step 150 also forms a tortuous gap along its surface to eliminate a direct line of sight between the powered electrode 126 and the chamber wall 102, thereby reducing the possibility of secondary plasma excitation occurring between the powered electrode 126 and the chamber wall 102.

[0044] The controller 190 controls the operation of the substrate processing system 100. The controller operates the gas delivery system 192 to deliver gases to the substrate processing system 100 at appropriate times during the process. The controller 190 can monitor the RF voltage or the RF voltage and current through the sensor 196 and control the power provided by the RF power source 170. The controller 190 controls the vacuum pumps 136 and 143 to control the pressure in the substrate processing system.

[0045] One or more heaters 194, such as one or more resistive heaters, may be used to control the temperature of the substrate support and / or substrate in one or more zones. One or more temperature sensors 196 may be used to measure the temperature in the one or more zones. The controller 190 outputs power to the one or more heaters 194 based on one or more temperature values ​​sensed by the one or more temperature sensors 196 in the one or more zones and based on one or more sets of feed-forward values.

[0046] Reference now Figure 2 and 3 , shows an example of a feedforward control system. Figure 2 In the embodiment of the present invention, the feedforward control system 200 includes a controller 210, one or more feedback sensors 214, and one or more actuators 218. The controller 210 includes a feedforward module 230, a recipe 234, and one or more drivers 242 to generate control signals for the actuators 218. In some examples, when the feedforward for automatic calibration is enabled, the controller 210 generates a forecast that the first substrate will be used to calibrate the feedforward value. The multi-step recipe is run by the controller 210 using the default feedforward value.

[0047] During processing, measured parameters (e.g., temperature, pressure, etc.) are stored as a function of time. After executing the process recipe, the feed-forward values ​​are adjusted during each step of the multi-step recipe based on the measured parameters to create one or more feed-forward values. During processing of subsequent substrates, the new feed-forward values ​​are used to control the one or more actuators 218. As will be further described below, additional refinements of the feed-forward values ​​may be performed during processing of subsequent substrates.

[0048] exist Figure 3 In FIG. 3 , the feedforward control system 300 includes a controller 310, one or more temperature sensors 314, and one or more heaters 318. The controller 310 includes a feedforward module 330, a recipe 334, and one or more heater drivers 342 for generating heater control signals.

[0049] Reference now Figure 4 , a method for providing feedforward control is shown. At 410, the method determines whether a new multi-step recipe is to be executed. When 410 is true, the method sets the auto-calibrated feedforward to disabled at 414. At 418, the feedforward value is set to a predetermined value such as zero.

[0050] At 422, the method determines whether the user has enabled feed-forward for automatic calibration. When 422 is true, the method optionally generates a forecast at 428 that the first substrate will be used to calibrate the feed-forward value. At 430, the multi-step recipe is executed while the substrate is in the process chamber. The duty cycle of the heater is stored at predetermined time intervals.

[0051] At 434, a parameter such as temperature or other type of parameter is measured as a function of time during the process. At 438, a feed-forward value is set during the step of the multi-step recipe based on the change in the parameter measured during the step and the duration of the step. In some examples, the measured parameter is time-shifted relative to the duty cycle value and compared to the desired parameter of the process step, and the corresponding feed-forward value is adjusted based thereon. In some examples, the parameter is time-shifted by the delay of the system or plant.

[0052] At 442, the method determines whether to run another substrate. If 442 is true, the method runs a multi-step recipe using the auto-calibrated feed-forward values ​​while placing the substrate in the process chamber. At 450, a parameter is measured as a function of time during processing.

[0053] At 460, the method compares the difference between the parameter and the predetermined value to a predetermined threshold. If it is determined at 460 that the difference is greater than the predetermined threshold (or the user has not stopped calibration), the method time shifts the parameter by the delay at 462. At 464, the feedforward parameter is adjusted based on the change in the parameter during the step and the duration of the step.

[0054] Reference now Figure 5 , in accordance with the present invention, the duty cycle and temperature as a function of time are shown for a substrate processing system without feedforward. As described above, the temperature sensor has a very long thermal delay (e.g., 50-55 seconds). For example, during process step 510, the pressure increases and the substrate experiences cooling. The temperature sensor detects a drop in temperature after a long delay. As a result, the controller increases the duty cycle of the heater too late and the substrate experiences a significant temperature difference (delta). The substrate experiences additional cooling (along with the sensing delay) in subsequent steps, and the heater cannot control the temperature of the substrate in a stable manner during the process.

[0055] Reference now Figure 6 , according to the present disclosure, the duty cycle and temperature as a function of time for a substrate processing system with feedforward control are shown. The controller adjusts the feedforward value based on measurements taken during processing of a first substrate (and additional adjustments thereafter). As a result, the heater is controlled using feedforward control and the temperature of the substrate is maintained in a stable manner.

[0056] Reference now Figure 7 , a method 700 for determining a feedforward value is shown. At 710, a duty cycle for a first substrate is recorded during processing of the substrate. At 714, linear interpolation or other methods can be used to match the duty cycle and the timestamps of the measured temperature values. At 718, data smoothing or other techniques can be used to clean the temperature data. At 722, a measurement delay for the sensor is retrieved. In some examples, the measurement delay is input by a user. At 730, the temperature data for each process step is time-shifted by the delay. At 734, based on the initial and final temperature values ​​during the process step, a temperature change ΔT during the process step is determined. A time change ΔS for the process step is also determined by subtracting the final time at the end of the process step from the initial time at the beginning of the process step. At 738, an average duty cycle DC delivered during the process is determined. avg (No time shift).

[0057] If it is determined at 742 that the processed substrate is the first substrate, then for the step at 744, the feed forward command is set equal to SetFFcommand=DCavg =FF_Constant*(ΔT / ΔS). Otherwise, for the process step at 750, the feedforward command is set equal to SetFFcommand=DC avg –(FF_Constant / F)*(ΔT / ΔS), where F is a constant that slows down the calibration of the feedforward value after the initial feedforward value is calculated for the first substrate. In some examples, F can be in the range of 1 to 10, but other values ​​can be used. In some examples, F is set to 1 to provide equal weighting to the first and subsequent iterations. FF_Constant is a value determined so that the feedforward value can be scaled for different pedestals. Different pedestals will have different power output levels. As a result, the duty cycle value will vary accordingly. The FF_Constant can be adjusted or scaled to accommodate these differences.

[0058] Reference now Figure 8 , a method 800 for adjusting feedforward operation is shown. At 820, the method determines whether feedforward learning is enabled. If 820 is true, the method compares the measured substrate temperature to the desired substrate temperature. At 828, the method determines whether the substrate temperature deviates by more than + / -Z°C. In some examples, Z is equal to 10°C, but other temperature values ​​can be used. If 828 is true, the method resets the feedforward value and sends an alarm message at 830.

[0059] If 828 is false, the method determines at 840 whether the substrate temperature deviates by more than + / -X°C. In some examples, X is equal to 2°C, but other temperature values ​​may be used. If 840 is false, the FF value is locked at 844. If 840 is true, the method continues at 850 and determines whether the FF value was previously locked. If 850 is false, the method returns to 820. If 850 is true, the method continues at 852. At 852, the method determines whether the substrate temperature deviates by more than + / -Y°C. In some examples, Y is equal to 5°C, but other temperature values ​​may be used. If 852 is false, the method continues at 820. If 852 is true, the method continues at 854, an alarm is issued and a message is sent to initialize relearning.

[0060] The foregoing description is merely illustrative in nature and is by no means intended to limit the present disclosure, its application or use. The broad teachings of the present disclosure can be implemented in various forms. Therefore, although the present disclosure includes specific examples, the true scope of the present disclosure should not be so limited, because when studying the drawings, the specification and the appended claims, other modifications will become apparent. It should be understood that one or more steps in the method can be performed in different orders (or simultaneously) without changing the principles of the present disclosure. In addition, although each embodiment is described above as having certain features, any one or more of those features described with respect to any embodiment of the present disclosure can be implemented in the features of any other embodiment and / or combined with the features of any other embodiment, even if the combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and the replacement of one or more embodiments with each other remains within the scope of the present disclosure.

[0061] Various terms including "connected," "engaged," "coupled," "adjacent," "near," "on," "above," "below," and "disposed" are used to describe spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.). Unless explicitly described as "direct," when a relationship between a first and a second element is described in the above disclosure, the relationship may be a direct relationship in which no other intermediate elements exist between the first and second elements, but may also be an indirect relationship in which one or more intermediate elements exist (spatially or functionally) between the first and second elements. As used herein, the phrase "at least one of A, B, and C" should be interpreted to mean a logical (A or B or C), using a non-exclusive logical OR, and should not be interpreted to mean "at least one of A, at least one of B, and at least one of C."

[0062] In some implementations, the controller is part of a system, which can be part of the above examples. Such a system can include a semiconductor processing device, which includes one or more processing tools, one or more chambers, one or more platforms for processing, and / or specific processing components (wafer pedestals, gas flow systems, etc.). These systems can be integrated with electronic devices for controlling their operation before, during, and after the processing of semiconductor wafers or substrates. The electronic device can be referred to as a "controller", which can control various components or subcomponents of one or more systems. Depending on the processing requirements and / or the type of system, the controller can be programmed to control any of the processes disclosed herein, including the delivery 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 rate settings, fluid delivery settings, position and operation settings, wafer delivery in and out tools and other delivery tools and / or load locks connected to or interfaced with a specific system.

[0063] Broadly speaking, a controller can be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receive instructions, issue instructions, control operations, enable cleaning operations, enable endpoint measurements, etc. The integrated circuits can include a chip in the form of firmware that stores program instructions, a digital signal processor (DSP), a chip defined as an application specific integrated circuit (ASIC), and / or one or more microprocessors, or a microcontroller that executes program instructions (e.g., software). The program instructions can be instructions transmitted to the controller in the form of various individual settings (or program files) that define operating parameters for performing specific processing on or for a semiconductor wafer or system. In some embodiments, the operating parameters can be part of a recipe defined by a process engineer to complete one or more processing steps in the preparation of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of a wafer.

[0064] In some implementations, the controller may be part of or coupled to a computer that is integrated with the system, coupled to the system, otherwise networked to the system, or a combination of these. For example, the controller may be in the "cloud", or in all or part of a wafer fab host computer system that enables remote access to wafer processing. The computer may enable remote access to the system to monitor the current progress of a manufacturing operation, study the history of past manufacturing operations, study trends or performance criteria from multiple manufacturing operations, change parameters of a current process, set a processing step after the 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 via a network (which may include a local network or the Internet). The remote computer may include a user interface that enables input or programming of parameters and / or settings, which are then transmitted 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 processing to be performed and the type of tool that interfaces with or is controlled by the controller. Thus, as described above, the controller may be distributed, such as by including one or more discrete controllers networked together and working toward a common purpose (e.g., processing and control as described herein). An example of a distributed controller for such a purpose is one or more integrated circuits on a chamber that communicate with one or more integrated circuits located remotely (e.g., at a platform level or as part of a remote computer), which combine to control the processing on the chamber.

[0065] Example systems may include, but are not limited to, plasma etch chambers or modules, deposition chambers or modules, spin rinse chambers or modules, metal plating chambers or modules, cleaning chambers or modules, chamfer 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 any other semiconductor processing system that may be associated with or used in the preparation and / or manufacture of semiconductor wafers.

[0066] As described above, depending on one or more process steps to be performed by the tool, the controller can communicate with one or more other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout the factory, a host computer, another controller, or tools used in material transport to transport wafer containers to and from tool locations and / or load ports in a semiconductor manufacturing facility.

Claims

1. A substrate processing system for processing a substrate, the substrate processing system comprising: a sensor for generating a sensed value of a parameter of the substrate processing system; an actuator for adjusting the parameter of the substrate processing system; and a controller in communication with the sensor and the actuator and configured to: processing a first substrate during a process by using the sensed value to adjust a control value for controlling the actuator without feed-forward control, wherein the sensed value is delayed and causes instability in the parameter; Automatically calibrating a feedforward value for processing a second substrate based on the sensed value and the control value, wherein automatically calibrating the feedforward value comprises: time-shifting the sensed value by a delay period to produce a time-shifted sensed value; determining changes in the time-shifted sensed values ​​during a plurality of etching or deposition steps of the process; determining the feed-forward values ​​for the plurality of etching or deposition steps of the process based on the changes in the sensed values ​​during a corresponding one of the plurality of etching or deposition steps; and The second substrate is processed while controlling the actuator using the feedforward value.

2. The substrate processing system according to claim 1, wherein: In order to automatically calibrate the feedforward value, the controller is further configured to: determining durations of the plurality of etching or deposition steps of the process; determining a feed-forward value for the plurality of etching or deposition steps of the process based on the control value for the actuator, the change in the time-shifted sensed value during the corresponding one of the plurality of etching or deposition steps, and the duration of the corresponding one of the plurality of etching or deposition steps of the process; as well as processing the second substrate based on the feedforward value; Wherein, automatically calibrating the feedforward value comprises: determining an average value of one of the control values; determining a scaling value based on one of the changes in the time-shifted sensing values ​​and a duration of one of the multiple etching or deposition steps; and determining one of the feedforward values ​​based on a difference between the average value and the scaling value. The substrate processing system of claim 2 , wherein the delay period is longer than 5 seconds.

4. The substrate processing system according to claim 2, wherein: The controller is also configured to perform data smoothing on the sensed value from the sensor.

5. The substrate processing system according to claim 2, wherein: The controller is also configured to perform interpolation to match time stamps of the sensed values ​​and the control values.

6. The substrate processing system according to claim 2, wherein: The controller is also configured to determine an average value of the control value during the plurality of etching or deposition steps of the process.

7. The substrate processing system according to claim 6, wherein: The controller is also configured to determine the feed-forward value for the multiple etching or deposition steps of the process based on the average value, the change in the sensed value during the multiple etching or deposition steps of the process, and the duration of the multiple etching or deposition steps of the process.

8. The substrate processing system according to claim 7, wherein based on DC avg -FF_Constant*(ΔT / ΔS) calculates the feedforward value for the second substrate, where DC avg corresponds to the average value, ΔT corresponds to the change in the sensed value during the plurality of etching or deposition steps of the process, ΔS corresponds to the duration of the plurality of etching or deposition steps of the process, and FF_Constant corresponds to a scaling factor.

9. The substrate processing system according to claim 7, wherein based on DC avg -FF_Constant / K*(ΔT / ΔS) calculates the feedforward value for the third substrate, where DC avg corresponds to the average value, ΔT corresponds to the change in the sensed value during the multiple etching or deposition steps of the process, ΔS corresponds to the duration of the multiple etching or deposition steps of the process, FF_Constant corresponds to a scaling factor, and K is a calibration reduction factor.

10. The substrate processing system of claim 1, wherein the sensor comprises a temperature sensor.

11. The substrate processing system of claim 10, wherein the actuator comprises a heater for a substrate support of the substrate processing system.

12. The substrate processing system according to claim 11, wherein: The control value includes a duty cycle value.

13. The substrate processing system according to claim 1, wherein: The substrate processing system performs at least one of deposition and etching.

14. A method for processing a substrate in a substrate processing system, comprising: generating a sensed value of a parameter of the substrate processing system; adjusting the parameters of the substrate processing system; processing a first substrate during the process by using the sensed value to adjust a control value for controlling an actuator without feed-forward control, wherein the sensed value is delayed and causes instability in the parameter; Automatically calibrating a feedforward value for processing a second substrate based on the sensed value and the control value, wherein automatically calibrating the feedforward value comprises: time-shifting the sensed value by a delay period to produce a time-shifted sensed value; determining changes in the time-shifted sensed values ​​during a plurality of etching or deposition steps of the process; and determining the feed-forward values ​​for the plurality of etching or deposition steps of the process based on the changes in the time-shifted sensed values ​​during a corresponding one of the plurality of etching or deposition steps; and The second substrate is processed while controlling the actuator using the feedforward value.

15. The method according to claim 14, wherein: Automatically calibrating the feedforward value includes: determining durations of the plurality of etching or deposition steps of the process; determining the feed-forward value for the plurality of etching or deposition steps of the process based on the control value for the actuator, the change in the time-shifted sensed value during the corresponding one of the plurality of etching or deposition steps, and the duration of the corresponding one of the plurality of etching or deposition steps of the process; and The second substrate is processed based on the feedforward value. The method of claim 15 , further comprising performing data smoothing on the sensed values ​​from a sensor.

17. The method of claim 16, further comprising performing interpolation to match time stamps of the sensed value and the control value.

18. The method of claim 15, further comprising determining an average of the control value during the plurality of etching or deposition steps of the process.

19. The method of claim 18, further comprising determining the feed-forward values ​​for the multiple steps of the process based on the average value, the variation of the sensed values ​​during the multiple etching or deposition steps of the process, and the duration of the multiple etching or deposition steps of the process.

20. The method according to claim 19, further comprising: avg -FF_Constant*(ΔT / ΔS) calculates the feedforward value for the second substrate, where DC avg corresponds to the average value, ΔT corresponds to the change in the sensed value during the plurality of etching or deposition steps of the process, ΔS corresponds to the duration of the plurality of etching or deposition steps of the process, and FF_Constant corresponds to a scaling factor.

21. The method according to claim 14, wherein: The control value includes a duty cycle value.

22. The method of claim 14, further comprising performing at least one of etching and deposition using the substrate processing system.

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