Electrostatic chuck heater resistance measurement for estimating temperature

Abstract

A controller includes a voltage sensor coupled to a heater trace integrated in an electrostatic chuck, the voltage sensor configured to sense a voltage difference across the heater trace, wherein the heater trace is associated with a heater zone. The controller includes a current sensor coupled to the heater trace and configured to sense a current in the heater trace. The controller includes a resistance identifier configured to identify a resistance of the heater trace based on the voltage difference and the sensed current. The controller includes a temperature correlator configured to estimate a temperature of the heater zone based on the resistance and a correlation function of the heater trace. The correlation function uses a temperature coefficient of resistance of the heater trace.

Description

Technical Field

[0001] This embodiment relates to an electrostatic chuck (ESC) for processing substrates such as semiconductor wafers. The ESC can be used to support the semiconductor substrate in a plasma reaction chamber where etching or deposition processes are performed. In particular, this embodiment relates to estimating the temperature of the heater region by measuring the resistance of the heater traces within the heater region of the ESC without using a temperature sensor located in the heater region of the ESC. Background Technology

[0002] Many modern semiconductor manufacturing processes are performed in plasma processing modules, where the substrate is held on a substrate holder while exposed to plasma. Temperature control of the substrate during plasma processing operations is a factor that can affect the outcome of the processing. To provide control over the substrate temperature during plasma processing operations, accurate and reliable measurement of the substrate holder temperature is required to infer the temperature of the substrate held thereon.

[0003] The background description provided herein is for the purpose of presenting the general context of this disclosure. The work of the currently designated inventors described within the scope of this background section and in the aspects of the description that cannot be identified as prior art at the time of filing does not expressly or imply an admission that it is prior art to this disclosure.

[0004] It is against this backdrop that the implementation plan for this public disclosure came into being. Summary of the Invention

[0005] This embodiment relates to solving one or more problems found in related art, and specifically includes an electrostatic chuck for a plasma processing chamber, wherein the ESC includes heater traces in the heater region of the ESC, wherein the heater traces are configured to sense temperature through a defined resistance of the heater traces. Several inventive embodiments of this disclosure are described below.

[0006] Embodiments of this disclosure include a controller comprising a voltage sensor coupled to a heater trace integrated in an electrostatic chuck, the voltage sensor being configured to sense a voltage difference across the heater trace, wherein the heater trace is associated with a heater region. The controller includes a current sensor coupled to the heater trace and configured to sense a current in the heater trace. The controller includes a resistance identifier configured to identify the resistance of the heater trace based on the voltage difference and the sensed current. The controller includes a temperature correlator configured to estimate the temperature of the heater region based on the resistance and a correlation function of the heater trace. The correlation function uses a temperature coefficient of the resistance of the heater trace.

[0007] Other embodiments of this disclosure include a user interface configured to provide information to a user. The user interface can be located on a display outside the plasma processing chamber. This display is configured to show information related to a first heater region of the electrostatic chuck of the plasma processing chamber. This information includes a first temperature associated with the first heater region. The first temperature is determined by a first temperature controller configured to sense a voltage difference across a first heater trace associated with the first heater region. The first temperature controller is configured to sense a current within the first heater trace. The first temperature controller is configured to identify the resistance of the first heater trace based on the voltage difference and the sensed current. The first temperature controller is configured to estimate the first temperature based on the resistance and a correlation function of the first heater trace.

[0008] The user interface may include a warning that provides suggestions, including at least one action to be taken based on the information. Specifically, the first temperature is determined by a first temperature controller configured to sense a voltage difference across a first heater trace integrated in the first heater region; sense a current within the first heater trace; identify the resistance of the first heater trace based on the voltage difference and the sensed current; and estimate the first temperature based on the resistance and a correlation function of the first heater trace.

[0009] Embodiments of this disclosure include an electrostatic chuck (ESC) for a plasma processing chamber, wherein the ESC is configured to support a substrate during processing. The ESC includes a first heater region. The ESC includes a first heater trace integrated into the heater region and providing heat to the heater region. The first heater trace has a first input and a first output. A first temperature controller is configured to estimate the temperature in the first heater region. The temperature controller is configured to sense a voltage difference across the first heater trace and sense a first current in the first heater trace. The first temperature controller is configured to identify a first resistance of the first heater trace based on the sensed first voltage difference and the sensed first current. The first temperature controller is configured to estimate a first temperature of the first heater region based on the identified first resistance and a first correlation function of the first heater trace, wherein the first correlation function uses a first temperature coefficient of the resistance of the first heater trace.

[0010] Other embodiments of this disclosure include a method for controlling the temperature of an electrostatic chuck (ESC) in a plasma processing chamber, the ESC including a heater region having a heater trace integrated therein. The heater trace has an input and an output and is configured to provide heat energy to the heater region. The method includes supplying power to the heater trace. The method includes sensing a voltage difference across the heater trace (between the input and output of the heater trace). The method includes sensing a current in the heater trace. The method includes identifying the resistance of the heater trace based on the sensed voltage difference and the sensed current. The method includes estimating the temperature of the heater region based on the identified resistance and a correlation function of the heater trace, without using a temperature sensor in the heater region, wherein the correlation function uses the temperature coefficient of the resistance of the heater trace.

[0011] Other embodiments of this disclosure include a plasma processing system for processing a substrate. The plasma processing system includes a reactor having an electrostatic chuck (ESC) for supporting the substrate, wherein the reactor is configured to receive process gases. The ESC includes a heater region. The ESC also includes a heater trace integrated within the heater region. The heater trace is configured to provide heat to the heater region and includes an input and an output. The plasma processing system includes a coupled temperature controller configured to sense a voltage difference between the input and output of the heater trace and to sense a current in the heater trace. The temperature controller is configured to identify the resistance of the heater trace based on the sensed voltage difference and the sensed current. The temperature controller is configured to estimate the temperature of the heater region based on the identified resistance and a correlation function of the heater trace, wherein the correlation function uses a temperature coefficient of the resistance of the heater trace.

[0012] Those skilled in the art will understand these and other advantages by reading the entire specification and claims. Attached Figure Description

[0013] The implementation scheme can be most appropriately understood by referring to the following description in conjunction with the accompanying drawings:

[0014] Figure 1 This disclosure describes a substrate processing system according to one embodiment of the present disclosure, which is used to process a wafer to form a film thereon, for example.

[0015] Figure 2According to one embodiment of the present disclosure, a system diagram of a reactor for processing a semiconductor substrate is shown. The reactor includes an electrostatic chuck having one or more heater regions heated by one or more heater traces, each heater trace being configured for temperature sensing, wherein the heater trace is controlled by one or more in-situ temperature controllers.

[0016] Figure 3A An embodiment of this disclosure shows a vertical cross-sectional view of an exemplary substrate holder configured as an electrostatic chuck, the electrostatic chuck including one or more heater regions heated by one or more heater traces, each heater trace being configured for temperature sensing.

[0017] Figure 3B One embodiment of this disclosure shows a heating system configured to provide heating to... Figure 3A The electrostatic chuck provides heat to specific heater areas, wherein a temperature controller controls the temperature of the heater area as measured by a corresponding heater trace, which is also configured to provide heat.

[0018] Figure 3C An implementation scheme shown in this disclosure is illustrated Figure 3B The temperature controller's power controller is configured to control the power supplied to the heater trace in order to control the temperature of the heater area.

[0019] Figure 4 This is a flowchart illustrating an embodiment of the present disclosure of a method for measuring the temperature of a temperature zone of an electrostatic chuck using a corresponding heater trace, the heater trace being configured for temperature sensing and providing heat energy to the heater zone.

[0020] Figure 5 A graph showing the correlation function between the resistance and temperature of a heater trace according to one embodiment of the present disclosure, the heater trace being configured to provide heat to the heater region of an electrostatic chuck, wherein the correlation function uses the temperature coefficient of the resistance of the heater trace.

[0021] Figure 6 One embodiment of this disclosure shows a control module for controlling the aforementioned system. Detailed Implementation

[0022] While the following detailed description contains many specific details for illustrative purposes, those skilled in the art will understand that many variations and modifications of these details are within the scope of the invention. Therefore, the aspects of the invention described below are set forth without prejudice to the generality of the following claims and without imposing any limitation.

[0023] Generally, various embodiments of this disclosure describe systems and methods for determining the approximate temperature of a corresponding heater region of an electrostatic chuck (ESC) by measuring the resistance of a corresponding heater trace used to heat the heater region and using a correlation function of the temperature coefficient of the resistance of that heater trace. Because embodiments of this disclosure do not require the insertion of dedicated temperature probes and / or sensors into cutouts in the ESC's layers (which would otherwise be dedicated sensor locations), the ESC itself can be thinner than conventional ESCs.

[0024] Furthermore, embodiments of this disclosure provide improvements in radio frequency (RF) uniformity on the ESC surface because the ESC ceramic does not contain cutouts, holes, etc., required for direct temperature sensing as is typically required in ESCs configured for temperature measurement.

[0025] Furthermore, since there is no need for a direct temperature sensor component to be embedded in the ESC (i.e., no fiber optic sensor, bandgap sensor, etc.), the ESC heating control system of the present disclosure can be manufactured more economically and saves a significant amount of cost compared to previous systems.

[0026] Furthermore, since the ESC heating systems of the embodiments of this disclosure do not require the use of temperature sensors as in previous heating systems, they can operate at high temperatures (e.g., operating ranges above 150 degrees Celsius) without having to consider heating limitations as in previous temperature sensors used to directly sense the heater zone temperature of the ESC (e.g., bandgap sensors can operate at a maximum of 150 degrees Celsius).

[0027] Furthermore, because the embodiments of this disclosure provide more accurate temperature measurements compared to previous heating control systems that provide open-loop control of the temperature in the heater region outside the RF thermal boundary, due to the poor accuracy of temperature measurement in those systems, in-situ (e.g., within the RF thermal boundary) closed-loop control of the heater trace is possible.

[0028] Furthermore, since there are no requirements on the thickness of the heater traces used to heat the heater region of the ESC, the heater traces can be made arbitrarily thin when measuring voltage and current for the purpose of determining temperature, and are still configured to measure voltage and current in the embodiments of this disclosure to determine the temperature of the heater traces and estimate the temperature of the heater region.

[0029] Furthermore, compared to conventional heater systems with a limited number of heater regions, which require space temperature sensors and have low resolution in temperature correlation between heater traces and corresponding heater regions due to the low thermal conductivity of ESC ceramics, embodiments of the present invention can provide further processing control when applying heat energy to multiple heater regions of the ESC. This is because the heater traces can be made arbitrarily thin by controlling those heater traces in a closed loop, thereby increasing the number of heater regions configured within the ESC (e.g., individually controlled vertical heater traces distributed throughout the ESC).

[0030] Furthermore, embodiments of this disclosure are configured to provide more accurate measurements of the temperature of the heater region because measuring the resistance of the heater trace within the heater region, rather than sensing the temperature of the ceramic in the heater region, reduces the impact of temperature crosstalk or leakage between regions experienced by conventional temperature sensing systems on the measurement.

[0031] Embodiments of this disclosure relate to plasma processing modules, such as those used in the following projects: plasma etching chambers or modules, deposition chambers or modules, rotary rinsing chambers or modules, metal plating chambers or modules, cleaning chambers or modules, beveled edge etching chambers or modules, physical vapor deposition (PVD) chambers or modules, chemical vapor deposition (CVD) chambers or modules, atomic layer deposition (ALD) chambers or modules, plasma-enhanced chemical vapor deposition (PECVD) chambers or modules, atomic layer etching (ALE) chambers or modules, ion implantation chambers or modules, orbital chambers or modules, and any other semiconductor processing systems that may be associated with or used in semiconductor wafer fabrication and / or manufacturing processes to include processes such as plating, electro-etching, electropolishing, electrochemical mechanical polishing, deposition, wet deposition, and through-silicon via (TSV) processing. Furthermore, embodiments of this disclosure are not limited to the examples provided herein and can be practiced in various plasma processing systems employing different configurations, geometries, and plasma generation technologies (e.g., inductively coupled systems, capacitively coupled systems, electron cyclotron resonance systems, microwave systems, etc.). Examples of plasma processing systems and plasma processing modules are disclosed in commonly owned U.S. Patent Nos. 8,862,855, 8,847,495, and 8,485,128, and U.S. Patent Application Serial No. 15 / 369,110, the entire contents of which are incorporated herein by reference. Importantly, the plasma processing module of embodiments of this disclosure includes an electrostatic chuck configured to support a substrate, wherein an approximate temperature of a corresponding heater region in the ESC can be determined by resistance measurements of a corresponding heater trace used to heat the heater region and a correlation function of the heater trace using the temperature coefficient of the resistance of the heater trace. The temperature of the heater region determined by the resistance measurements of the corresponding heater trace and the corresponding correlation function can be applied to heating other heating elements besides the heating element configured to support the substrate. For example, in other embodiments, the heating element may include a nozzle, ESC, support chuck, base, chamber component, or other structures or components that may be mounted in a reactor, chamber, processing module, etc., for processing the substrate.

[0032] Throughout this specification, the term "substrate" as used herein refers to a semiconductor wafer in the embodiments of this disclosure. However, it should be understood that in other embodiments, the term "substrate" may refer to a substrate formed of sapphire, GaN, GaAs, or SiC or other substrate materials, and may include glass panels / substrates, metal foils, metal sheets, polymer materials, or the like. Furthermore, in various embodiments, the substrate referred to herein may vary in form, shape, and / or size. For example, in some embodiments, the substrate referred to herein may correspond to a 200 mm, 300 mm, or 450 mm semiconductor wafer. Additionally, in some embodiments, the substrate referred to herein may correspond to a non-circular substrate, such as a rectangular substrate for a flat panel display, and may include other shapes.

[0033] Given the general understanding above regarding various embodiments, exemplary details of the embodiments will now be described with reference to the various accompanying drawings. Components and / or parts with similar numbers in one or more drawings indicate that they generally have the same configuration and / or function. Furthermore, the drawings may not be drawn to scale but are intended to illustrate and emphasize new concepts. It is apparent that embodiments of the invention can be implemented without some or all of these specific details. On the other hand, well-known processing operations are not described in detail herein to avoid unnecessarily obscuring the embodiments of the invention.

[0034] Figure 1 A reactor system 100 is described, which can be used to deposit films on a substrate, such as those formed in an atomic layer deposition (ALD) process. These reactors may utilize one or more heaters and can be configured using common terminals in this exemplary reactor to control the temperature for uniformity or custom settings. More specifically, Figure 1 A substrate processing system 100 for processing wafer 101 is described. The system includes a chamber 102 having a lower chamber portion 102b and an upper chamber portion 102a. A central pillar 160 is configured to support a base 140, which, in one embodiment, is a power supply electrode. The base 140 is electrically coupled to an RF power source 104 via a matching network 106. The RF power source 104 is controlled by a control module 110 (e.g., a controller). The control module 110 is configured to operate the substrate processing system 100 by executing process inputs and controls 108. The process inputs and controls 108 may include process recipes, such as power levels, timing parameters, process gases, mechanical movement of the wafer 101, etc., to deposit or form a film, for example, over the wafer 101.

[0035] The base 140 includes an electrostatic chuck (ESC) 310 configured to hold the substrate 101 when exposed to a plasma processing environment that generates plasma. Embodiments of this disclosure provide the determination and / or measurement of one or more heater regions of the ESC 310 during plasma processing operations within the reactor system 100. Specifically, the approximate temperature of a respective heater region is determined by measuring the resistance of the corresponding heater trace used to heat the heater region and by using a correlation function of the temperature coefficient of resistance of the heater trace.

[0036] The central support 160 also includes lifting pins (not shown), each actuated by a corresponding lifting pin actuation ring 120, controlled by a lifting pin controller 122. The lifting pins are used to lift the wafer 101 from the base 140 so that an end effector can pick up the wafer 101 and lower it after placement by the end effector. The substrate processing system 100 also includes a gas supply manifold 112 connected to process gas 114 (e.g., a gaseous chemical supply source for the facility). Depending on the process being performed, the control module 110 controls the delivery of process gas 114 via the gas supply manifold 112, chamber pressure, RF power generated from one or more RF power sources, exhaust pumps, etc. The selected gas then flows into the nozzle 150 and is distributed in a spatial volume defined between the nozzle 150 surface facing the wafer 101 and the wafer 101 placed above the base 140. In the ALD process, the gas may be a reactant selected for absorption or reaction with absorbed reactants.

[0037] Furthermore, the gas may or may not be premixed. Appropriate valves and mass flow control mechanisms can be employed to ensure the correct gas is delivered during the deposition and plasma treatment phases of the process. The process gas exits the chamber via an outlet. A vacuum pump (e.g., a single- or two-stage mechanical dry pump and / or turbomolecular pump) extracts the process gas and maintains an appropriate low pressure within the reactor via a closed-loop controlled flow-limiting device (e.g., a throttle valve or pendulum valve).

[0038] A support ring 175 is also shown surrounding the outer region of the base 140. The support ring 175 is configured to be positioned above a support ring support region located below a wafer support region at the center of the base 140. The support ring 175 includes an outer edge side (e.g., outer radius) of its disk structure and a wafer edge side (e.g., inner radius) of its disk structure, which is closest to the location of the wafer 101. The wafer edge side of the support ring 175 includes multiple contact support structures configured to lift the wafer 101 when the support ring 175 is lifted by a spider fork 180. Therefore, the support ring 175 is lifted together with the wafer 101 and can be rotated to, for example, another station in a multi-station system. In other embodiments, the chamber is a single-station chamber.

[0039] Furthermore, the in-situ heater temperature controller 200 is configured to control the temperature of one or more heater regions of the ESC310 on the substrate 140. The heater regions are used to precisely control the surface temperature of the ESC310 during substrate processing. The controllable multiple heater regions provide the ability to adjust the temperature traces (e.g., radial traces, etc.) of the ESC310 to compensate for varying environmental conditions (e.g., heat loss conditions, heat transfer conditions varying between different processing steps, etc.). In one embodiment, the in-situ heater temperature controller 200 can operate independently in a closed-loop configuration with heater traces of corresponding heater regions. In another embodiment, the in-situ heater temperature controller 200 can operate in conjunction with controller 110 in a closed-loop configuration with heater traces of corresponding heater regions. In one embodiment, the in-situ temperature controller 200 is located in chamber 102. In other embodiments, multiple temperature controllers may be located inside and outside chamber 102, as described below.

[0040] Figure 2 A system diagram of a reactor system 100 for processing a semiconductor substrate is shown. The reactor system includes a chamber 102 containing a base 140 having an ESC 310, wherein the ESC 310 includes one or more heater regions heated by one or more heater traces, and each heater trace is configured for temperature sensing, wherein, according to one embodiment of the present disclosure, the heater trace is controlled by one or more in-situ temperature controllers. A semiconductor substrate 101 is shown disposed above the base 140. A nozzle 150 is used to supply process gases for creating and generating plasma in the chamber 102. A gas supply source 114 supplies one or more gases according to the processing recipe being performed. A controller 110 is used to provide instructions to various components of the reactor system 100, including facilities such as the gas supply source 114, pressure controllers, temperature controllers, and other processing parameters.

[0041] Furthermore, the ESC310 of the base 140 can be configured with one or more heater regions, wherein in one embodiment, the heater regions are controllably heated during processing by one or more in-situ temperature controllers 200. For example, one or more in-situ temperature controllers 200 are configured to control the temperature of one or more heater regions of the ESC310. The in-situ temperature controllers 200 are located within the RF thermal boundary, such that each in-situ temperature controller 200 is exposed to processing conditions (e.g., increased temperature, pressure, etc.) by being positioned within chamber 102. In an embodiment, one or more heater regions of the ESC310 can be controlled by one or more in-situ temperature controllers and / or controller 110. That is, each heater region can be controlled by (1) one or more in-situ temperature controllers 200 independently, (2) individually by controller 110 (i.e., located outside the RF thermal boundary), or by (3) a combination of one or more in-situ temperature controllers 200 and / or controller 110. Having multiple temperature controllers capable of controlling the temperature of one or more heater zones can be beneficial for a variety of reasons, including but not limited to providing support in case of controller failure, achieving precise control by placing temperature controllers in one or more locations, and improving efficiency by assigning different controllers to different heater zones.

[0042] For illustrative purposes only, the ESC310 may be configured with two heater regions: an internal heater region heated by heater trace R-in (e.g., a resistive element) and an external heater region heated by heater trace R-out (e.g., a resistive element). A heater power supply 240A is configured to supply power to the external heater region disposed within the ESC310. In embodiments, an in-situ temperature controller 200, a controller 110, or a combination thereof, is coupled to heater power supplies 240A and 240B to control the power supplied to heater traces R-in and R-out, thereby controlling the temperature within the internal and external heater regions. For example, in one embodiment, the in-situ temperature controller 200 may be coupled to heater power supplies 240A and 240B in a closed-loop configuration to control the temperature within the internal and external heater regions. In another embodiment, the controller 110 may be coupled to heater power supplies 240A and 240B in a closed-loop configuration to control the temperature within the internal and external heater regions. In yet another embodiment, the in-situ temperature controller 200 and / or controller 110 are coupled in a closed-loop configuration to heater power supplies 240A and 240B to control the temperature within the internal and external heater regions. For clarity and brevity, several embodiments in this specification are described in which one or more heater regions of the ESC310 are controlled by the in-situ temperature controller 200; however, it should be understood that in other embodiments, the heater regions may be controlled individually or in various combinations by the in-situ temperature controller 200 and / or controller 110.

[0043] Specifically, the in-situ controller 200 provides resistance measurements for heating the corresponding heater traces of the corresponding heater region, where the resistance measurements are determined through one or more voltage and current measurements. Next, the approximate temperature of the corresponding heater region is determined using the resistance measurements and a correlation function of the heater traces, where the correlation function uses the temperature coefficient of the resistance of the heater traces. In a closed-loop configuration, the power to be supplied to the corresponding heater region can be determined using the determined approximate temperature of the heater region. For example, if the approximate temperature of the corresponding heater region is lower than the desired temperature, more power can be applied to the heater traces to increase the temperature of the heater region. On the other hand, if the approximate temperature of the corresponding heater region is higher than the desired temperature, less power can be applied to the heater traces to decrease the temperature of the heater region. Specifically, heater power supply 240A can be coupled to the internal heater region, while heater power supply 240B can be coupled independently to the external heater region. Typically, heater power supply 240A can supply voltage V-in to the heater trace R-in to influence temperature changes in the internal heater region. Similarly, heater power supply 240B can supply voltage V-out to heater trace R-out to affect temperature changes in the external heater area.

[0044] Figure 3A A vertical cross-sectional view of an exemplary substrate holder according to an embodiment of the present disclosure is shown. The substrate holder is configured as an electrostatic chuck and includes one or more heater regions heated by one or more heater traces, each heater trace being configured for temperature sensing. Specifically, the substrate holder may be an ESC310 or other type of substrate support member. For brevity and clarity, the substrate holder is described herein as an electrostatic chuck.

[0045] ESC310 may be the uppermost layer of base 140. Furthermore, ESC310 may include a base plate, an adhesive layer disposed above the base plate, and a ceramic layer disposed above the adhesive layer, wherein the adhesive layer secures the ceramic layer to the base plate. For simplicity and clarity, the base plate, adhesive layer, and ceramic layer are not shown. The ceramic layer may comprise one or more layers. The top surface of ESC310 may include an area configured to support substrate 101 during processing.

[0046] The ESC310 may include one or more clamping electrodes (not shown) coupled to a clamping voltage power supply (not shown) to clamp a supported substrate onto the ESC310. In some embodiments, a single electrode may be configured to generate an electric field for holding the substrate 101 on the ceramic layer. In other embodiments, two or more clamping electrodes may be configured to generate a differential voltage between the electrodes, which in turn generates an electric field for holding the substrate 101 on the ceramic layer.

[0047] As shown in the figure, the ESC310 includes one or more heater regions. For example, the ESC310 may include multiple heater regions, such as heater region 1 (320-A), heater region 2 (320-B), and so on up to heater region N (320-N), wherein each heater region can be controlled individually (e.g., one heater region can be controlled independently of another heater region). In one embodiment, these heater regions are located in the same horizontal plane. In another embodiment, these heater regions may be located in different horizontal planes, such that the first heater region and the second heater region can be located in different horizontal planes. Each heater region may include a heater trace (e.g., a resistive element) electrically coupled to a controller for controlling the supply of power to the corresponding heater trace (e.g., supplying power via a corresponding heater power supply - not shown). Each heater trace may be integrated into or embedded in the corresponding heater region and configured to provide heat energy to the corresponding heater region. For example, the heater trace can be manufactured and formed within a ceramic layer of the ESC310, such that the heater trace is disposed inside the ceramic layer. In this way, the heat energy generated by the heater trace can be transferred to the ceramic layer. Each heater trace has an input terminal and an output terminal. Each heater trace can be controlled by a corresponding in-situ temperature controller 200. For example, the corresponding in-situ temperature controller 200 can be coupled between the input terminal and the output terminal of the corresponding heater trace. As previously mentioned, the controller can be the in-situ temperature controller 200, controller 110, or a combination thereof. For example, heater region 1 is coupled to in-situ temperature controller A (200A) via input line 305A (e.g., coupled to the input terminal of heater trace 1) and output line 307A (e.g., coupled to the output terminal of heater trace 1). That is, in-situ temperature controller A (200A) is coupled between the input terminal and the output terminal of heater trace 1 of heater region 1 (320-A). Moreover, in-situ temperature controller B (200B) is coupled between the input terminal (e.g., via input line 305B) of heater region 2 (320-B) and the output terminal (e.g., via output line 307B) of heater trace 2. Other heater traces are similarly controlled to include an in-situ temperature controller N (200N) coupled between the input (e.g., via input line 305N) and output (e.g., via output line 307N) of the heater trace N in heater region N (320-N). In embodiments, one or more in-situ temperature controllers 200 can be used to control one or more heater regions, such that each heater region can be controlled by a corresponding in-situ temperature controller 200 in a one-to-one relationship, or the number of in-situ temperature controllers 200 can be less than the number of heater regions, or a single in-situ temperature controller 200 can be used.

[0048] Each in-situ temperature controller 200 is configured to sense the voltage difference across the corresponding heater trace and the current across the corresponding heater trace to determine the measured resistance of the heater trace. The measured resistance can be used to determine the approximate temperature of the corresponding heater region heated by the heater trace using a correlation function. The correlation function models the relationship between temperature and resistance based on the temperature coefficient of resistance of the heater trace. In this way, once the resistance of the heater trace and the corresponding temperature coefficient of resistance are known, the approximate temperature of the corresponding heater region can be determined. For example, in-situ temperature controller A (200A) is configured to sense the voltage at the input terminal of heater trace 1 in heater region 1 (320-A) and the voltage at the output terminal of heater trace 1, thereby measuring or calculating the voltage difference across heater trace 1. Furthermore, in-situ temperature controller A (200A) is configured to sense the current through heater trace 1. This current should be consistent throughout heater trace 1 and can be measured at one or more locations (e.g., above line 307A). The resistance measurement value can be determined by the sensed voltage difference and the sensed current. The approximate temperature of the corresponding heater region is then determined using the corresponding correlation function.

[0049] Therefore, the approximate temperature of the heater region can be determined without using a temperature sensor embedded in the ESC310. Specifically, a corresponding in-situ temperature controller 200 is configured to determine the approximate temperature of the corresponding heater region without using a temperature sensor embedded in the ESC310. The in-situ temperature controller is configured to sense and / or connect to circuitry that provides current to generate heat in the heater region of the ESC310 containing the corresponding heater trace, so as to sense the voltage and / or current across the heater trace. The sensing and / or connection can be performed outside the ceramic layer (e.g., using leads, connecting to circuitry, etc.) and in an RF thermal environment. In other embodiments, current sensing, voltage sensing, resistance measurement and / or determination, and temperature measurement and / or determination can be programmed into the in-situ temperature controller 200 via algorithms.

[0050] In one embodiment, the in-situ temperature controller (e.g., 200A, 200B...200N) is located within the RF boundary 330, such that the controller is situated within the RF thermal environment of chamber 102, for example, exposed to the processing conditions of processing chamber 102. In this manner, embodiments of this disclosure provide in-situ resistance measurement within the RF thermal environment and further provide in-situ control of the power supplied to the respective heater traces. The in-situ temperature controller 200 can be mounted on an ESC control board configured to drive the heater regions and provide communication with a user interface located outside the RF boundary (e.g., an RF cold environment), e.g., via fiber optic cabling to reduce RF feedback. That is, the in-situ temperature controller 200 can be configured to control the power supplied to the respective heater traces for heating the respective heater regions. In one embodiment, the power is supplied using pulse width modulation (PWM). With each in-situ temperature controller 200, the control board is configured to measure the voltage and current across each heater trace in the respective heater region and calculate the approximate temperature of the respective heater region of ESC 310, as previously described.

[0051] Figure 3B This displays a heating system configured to provide heat energy to Figure 3A In a specific heater region of the electrostatic chuck 310, according to one embodiment of the present disclosure, an in-situ temperature controller 200 controls the temperature of the heater region 320 as measured by a corresponding heater trace 345 configured to provide heat energy to the heater region 320. Specifically, the heater trace 345 includes an input terminal 351 and an output terminal 352, wherein the heater trace 345 is coupled to a power supply 240. For example, the power supply 240 supplies power to the input terminal 351 via line 305. The power supply 240 is coupled to the output terminal 352 via line 307. Furthermore, in one embodiment, the in-situ temperature controller 200 is coupled between the input terminal 351 and the output terminal 352 of the heater trace. For example, the in-situ temperature controller 200 may be coupled to lines 305 and 307 to sense voltage and / or current. Additionally, the in-situ temperature controller 200 is coupled to the power supply 240 to transmit control signals. For example, the heater trace 345, the in-situ temperature controller 200, and the power supply 240 can be coupled in a closed loop, such that the in-situ temperature controller 200 can control the power to be supplied to the heater trace 345 based on the calculated temperature of the heater region 320 and the desired temperature of the heater region 320.

[0052] Specifically, the in-situ temperature controller 200 is configured to perform in-situ resistance measurements on the heater trace 345 to determine the approximate temperature of the corresponding heater region 320 of the ESC 310. In one embodiment, it is not necessary to use a temperature sensor embedded or located in the corresponding heater region to determine this approximate temperature. Embodiments of this disclosure provide measurements of voltage, current, and / or resistance, thereby determining the approximate temperature at high operating temperatures (e.g., exceeding 150 degrees Celsius) at a significantly lower cost than existing temperature sensing systems. Furthermore, since there are no temperature sensing cutouts and connecting lines in at least one layer of the ESC, the temperature sensing system of embodiments of this disclosure provides improved RF uniformity over the ESC coverage area.

[0053] The in-situ temperature controller 200 is configured to perform voltage sensing 360 by measuring the voltage across the heater trace 345. For example, in one embodiment, the in-situ temperature controller 200 may be coupled to the input terminal 351 of the heater trace 345 to measure the input voltage (V-in) of the heater trace 345. The in-situ temperature controller 200 may be coupled to node 355 of the analog heater trace's input terminal 351. Furthermore, the in-situ temperature controller 200 may be coupled to the output terminal 352 of the heater trace 345 to measure the output voltage (V-out) of the heater trace 345. The in-situ temperature controller 200 may be coupled to node 357 of the analog output terminal 352. The in-situ temperature controller 200 may be configured to determine the voltage difference between the input voltage and the output voltage.

[0054] Furthermore, the in-situ temperature controller 200 is configured to perform current sensing 370 by measuring the current flowing through the heater trace 345. For example, the in-situ temperature controller 200 may be coupled to any node 356 or 355 of the input line 305 to measure a current I that also flows through the heater trace 345. Additionally, the in-situ temperature controller 200 may be coupled to any node 357 or 358 of the output line 307 to measure the same current I that also flows through the heater trace 345. Thus, the in-situ temperature controller 200 may be configured to measure and / or sense the voltage and current across the heater trace 345 to calculate an approximate temperature of the heater region 320 of the ESC 310, as further described below. Additionally, the power controller 380 is configured to determine what power to supply to the heater trace 345 based on the determined approximate temperature of the heater region 320 and a possible desired temperature of the heater region 320, as further described below. For example, the power controller 380 can supply a specific voltage level to the power supply 240 to supply the heater trace 345, or it can supply an incremental voltage to the power supply 240 to regulate the voltage along the negative or positive direction. The heat generated by the heater trace 345 (such as that generated by the power supply) is transferred to the corresponding heater region in the ESC.

[0055] Figure 3C An implementation scheme shown in this disclosure is illustrated Figure 3B The in-situ temperature controller 200 has a power controller 380. The in-situ temperature controller 200 is configured to control the power supplied to the heater trace 345 to control the temperature of the heater region 320. As previously described, the in-situ temperature controller 200 is configured to sense the voltage difference (V) across the heater trace 345 in real time. htr ), and sense the current (I) passing through the heater trace 345 in real time. htr ).

[0056] Additionally, the resistance identifier 365 of the power controller 380 is configured to identify the resistance of the heater trace 345 based on the sensed voltage difference and the sensed current (e.g., in real time). Specifically, the resistance (R) of the heater trace 345 in the heater region 320 can be calculated using the following equation. htr ):

[0057] R htr =V htr / I htr (1)

[0058] The approximate temperature 395 of the corresponding heater region 320 of ESC 310 can be determined by temperature correlator 385 based on the identified resistance (R). htrThe temperature is obtained by a correlation function of the resistance temperature coefficient of the heater trace and the resistance temperature coefficient of the heater trace. In one embodiment, the correlation function is linear. In other embodiments, the correlation function is nonlinear. In one embodiment, an approximate temperature 395 of the respective heater region 320 is determined without a temperature sensor embedded or located in the heater region 320 of the ESC 310. As previously mentioned, in one embodiment, no sensor is provided in the ESC 310 for determining the temperature of the respective heater region. Specifically, temperature sensors, voltage sensors, and current sensors are not provided within the ESC 310 and are not embedded within the ESC 310 (e.g., in cutouts in the layers). Current and voltage sensing can be performed by an in-situ temperature controller 200 located outside the ESC and within the RF thermal environment. For example, probes, connections, etc., can be used to sense voltage and current. Furthermore, in one embodiment, voltage sensing, current sensing, resistance measurement and / or determination, and temperature measurement and / or determination can be programmed into the in-situ temperature controller 200 by an algorithm.

[0059] Specifically, the relevant function of the corresponding heater trace (e.g., trace 345) is based on several parameters, including the calibration resistance (R) of heater trace 345 at the calibration temperature (T0) of heater trace 345. htr@T0 and the temperature coefficient of resistance (TCR) of heater trace 345. htr In one embodiment, the calibration measurement can be determined at a calibration (predefined) temperature T0 (e.g., approximately 20 degrees Celsius, room temperature). For example, calibration can be performed at the factory during manufacturing. That is, at a known temperature T0, the resistance (R) can be measured and / or calibrated. htr@T0 Typically, the temperature coefficient (TCR) of resistance is... htr The change in resistance of a specific material for each degree of temperature variation is defined. That is, as the temperature of a specific material changes, the relevant resistance of that material will also change, as defined by its corresponding temperature coefficient of resistance. The temperature coefficient of resistance of the heater trace and / or the heater trace embedded in the ESC can be known (e.g., predefined) and / or calibrated, as described below.

[0060] In some embodiments, heater trace 345 comprises tungsten as an electrical conductor. In other embodiments, heater trace 345 may particularly comprise one or more of molybdenum, tantalum, tungsten, palladium, ruthenium, platinum, and alloys for electrical conductivity. In one embodiment, the material used for heater trace 345 has a density of approximately 4.1 × 10⁻⁶. -3 The minimum temperature coefficient of resistance is (0.0041). In another embodiment, the material used for the heater trace 345 has a temperature coefficient of resistance of approximately 4.4 × 10⁻⁶. -3 The minimum temperature coefficient of resistance is (0.0044).

[0061] Due to the known or calibrated properties of the materials used for a particular heater trace (e.g., having a known temperature coefficient of resistance -- TCR) htr The approximate temperature of the corresponding heater region of the ESC (i.e., heated via the heater trace) is 395 (Temp). zone It can be calculated based on the following equation:

[0062] R htr =R htr@T0 *[1+TCR htr *(Temp zone –T0)] (2)

[0063] Because the resistance (Rhtr) of the heater trace can be measured, and the remaining parameters (calibration resistance at calibration temperature -- R) htr@T0 and the temperature coefficient of resistance -- TCR htr Known to be predefined and / or calibrated, the temperature of the heater trace can be determined. zone This temperature can be estimated as the temperature 395 of the corresponding heater region. The approximate temperature 395 of the heater region can be defined as the measured temperature of the heater region. Specifically, Equation 3 begins with Equation 2 and solves to obtain the real-time approximate temperature 395 of the heater region:

[0064] Temp zone =(R htr / R htr@T0 -1) / TCR htr +T0 (3)

[0065] In one embodiment, the correlation function is linear, wherein the correlation function correlates the resistance of the heater trace with the temperature of the heater trace and / or the approximate temperature of the corresponding heater region heated by the heater trace. That is, TCR htr It is constant within a suitable temperature range; therefore, the correlation function will be linear within this temperature range, where the slope of the correlation function is the temperature coefficient of the resistance—TCR. htr In one implementation scheme, TCR htr Calibration is performed on the material of the heater trace (used alone). In this case, the temperature response of the heater region approximates the temperature response of the heater trace used to heat the corresponding heater region. A good estimate can be made between the temperature responses of the heater region and the heater trace when the temperature coefficient of resistance of the material of the heater trace is assumed to be linear.

[0066] In other implementations, the correlation function is non-linear. That is, TCR htr It is not constant within a suitable temperature range. TCR htrThe slope of the curve for the relevant function at a specific point can still be defined. In one implementation, the TCR... htr Calibration is performed on the heater traces embedded within the ESC. Calibration can be performed when the correlation function is linear or nonlinear, but it is particularly useful when the correlation function is nonlinear to obtain more accurate temperature calculations. In this case, the correlation function can be calibrated over an appropriate temperature range for the heater traces embedded within the ESC. For example, measurements of the temperature of the heater region and the resistance of the heater traces can be performed to determine a more accurate correlation function, which defines the relationship between the calibration resistance of the heater traces and the calibration temperature response of the heater region heated by the heater traces.

[0067] An approximate temperature 395 of the heater region can be provided as an input to the temperature comparator 387 of the power controller 380. Alternatively, a desired temperature 390 of the heater region (e.g., as predefined by the process recipe) can be provided as an input to the temperature comparator 387. The temperature comparator 387 can be configured to determine the difference between the approximate temperature 395 and the desired temperature 390 of the heater region. Furthermore, the power selector 391 can be configured to analyze this difference and match the approximate temperature 395 of the heater region with the desired temperature 390. For example, the power selector 391 can be configured to apply a predetermined response to match these two values. Thus, the power selector 391 provides a response to be applied at the power supply 240 as an output 399, thereby controlling the power applied to the heater trace 345 of the heater region 320. This response can be determined through closed-loop analysis. In other words, the power selector 391 of the in-situ temperature controller 200 performs a closed-loop analysis of the approximate temperature 395 of the heater region 320 to control the power supplied by the power source 240 to the heater trace 345 so that the approximate temperature 395 matches the desired temperature 390 of the heater region (e.g., over the entire predetermined time period).

[0068] For example, power selector 391 can provide the voltage level (V-in) to be supplied by power supply 240 to heater trace 345 as output 399. In another embodiment, power selector 391 can perform iterative processing in response to a history of the measurement difference between the approximate temperature 395 and the desired temperature 390 of the heater region to change the voltage level (V-in) supplied by power supply 240 in order to match the approximate temperature 395 and the desired temperature 390 of the heater region within a predetermined time period.

[0069] Figure 3B and 3CThe logic components of the in-situ temperature controller 200 and power controller 380 illustrate exemplary configurations for performing various functions, such as voltage sensing, current sensing, resistance identification, temperature correlation, temperature comparator, power selection, power control, etc. It should be understood that the functionality of the logic components described within the in-situ temperature controller 200 and power controller 380 can be logically arranged in a variety of different configurations. For example, some functions of the power controller 380 can be separated and provided within the in-situ temperature controller 200, and vice versa.

[0070] Embodiments of this disclosure provide a multi-zone heating system for electrostatic chucks. For example, each zone can be heated using corresponding resistive elements. In one embodiment, a dual-zone heating system comprises circular heating zones, such as an inner heater zone having heater traces R-in (e.g., resistive elements) for heating and an outer zone having heater traces R-out (e.g., resistive elements) for heating. It should be understood that the dual-zone heating system is merely an example and various layout configurations can be supported. For example, a heating system with one or more heater zones can be provided, such as a three-heater-zone system comprising an inner zone, a middle zone, and an outer zone. The number of heater zones between systems can vary to include, for example, 1 to 5 heater zones, or 5 to 10 or 5 to 15, or more than 5 heater zones or more than 10 heater zones, or more than 20 heater zones, or more than 50 heater zones, or more than 75 heater zones, or more than 100 heater zones, or more than 125 heater zones. In other examples, heater regions can be grouped into layers, with one group of multiple heater regions on a horizontal layer, and at least one other layer containing another group of multiple heater regions. In other embodiments, heater regions can be oriented in various configurations, such as disc-shaped, circularly oriented heating coils, grids of single resistive elements, zigzag resistive elements, single resistive elements, etc. As an illustration of an embodiment, some layout configurations can provide continuous circular rings of resistive elements for multiple regions. As previously mentioned, resistive elements and / or heater traces for heating the respective heater regions can be integrated into the ceramic defining the base, on which a substrate for processing is then received.

[0071] In one embodiment, a multi-zone heating system is provided in one layer of the ESC, wherein these zones are arranged in a grid throughout the ESC. Each element in the grid can be independently controlled to provide thermal energy. For example, the grid can be configured as a 14×14 grid for heating elements, such as corresponding heater traces and / or resistive elements. In one embodiment, the number of heater zones can be provided in a one-to-one relationship, resulting in 14×14 heater zones. In another embodiment, some heating elements are provided for redundancy, such that the number of heater zones is less than the number of heating elements. For example, a configuration of 12×12 heater zones supported by a grid of 14×14 heater elements (e.g., heater traces, resistive elements, etc.) can exist. In other embodiments, the grid pattern of the heating elements can be symmetrical, asymmetrical, uniformly distributed throughout the grid pattern, non-uniformly distributed throughout the grid pattern, various shapes suitable for the outline of the ESC, etc. The heating system can be provided in one layer of the ESC and can be configured to provide fine-tuning of the thermal energy for the entire ESC.

[0072] In another embodiment, the heating system can be distributed across multiple layers of the ESC. For example, one layer can be used to fine-tune the thermal energy supplied to the ESC. Fine-tuning of the thermal energy can be provided using the aforementioned grid patterns for multi-zone heating systems (e.g., heating elements with a 12×12 grid, heating elements with a 14×14 grid, etc.). The heating system can also include one or more heating zones in another layer configured to provide coarse-tuning of the thermal energy applied to the ESC. For example, a ring of one or more heater zones can be provided throughout the ESC, such as a dual-heater zone ESC (e.g., two heater zones), a triple-heater zone ESC (e.g., three heater zones), or a quadruple-heater zone ESC (e.g., four heater zones).

[0073] In one embodiment, the embodiments of this disclosure are not limited by the low resolution of the temperature correlation between the heater trace and the measured temperature (e.g., via a temperature sensor) of the heater region due to the low thermal conductivity of the ceramic. In conventional temperature measurement and heating systems (e.g., using direct temperature sensors), the thickness of the heater trace cannot be less than a threshold (e.g., 10 mm) because, due to the aforementioned low-resolution temperature correlation, heater traces below this threshold cannot be accurately measured. This also limits the number of heater regions that can be provided in conventional heating systems with accurate temperature sensing (e.g., using direct temperature sensors). On the other hand, the embodiments of this disclosure have a high-resolution temperature correlation between the measured temperature of the heater trace and the heater region, due to the high resolution for voltage and current measurements with low noise. In this way, the embodiments of this disclosure can provide heater traces with a cross-section significantly lower than the previously imposed 10 mm threshold. Furthermore, the embodiments of this disclosure can provide heater traces with a cross-sectional width (e.g., the horizontal width of the cross-section) less than 10 mm and with arbitrary thickness. This is because high-resolution voltage and current measurements have low noise, can accurately measure voltage and current regardless of the thickness of the heater traces, and can more accurately measure the approximate temperature of the corresponding heater region. Furthermore, embodiments of the invention can provide further processing control when applying heat energy to multiple heater regions of the ESC, as the heater traces can be arbitrarily thinned through closed-loop control of those traces, thereby increasing the number of heater regions configured in the ESC (e.g., independently controlled vertical heater traces distributed throughout the ESC).

[0074] Figure 4 A flowchart 400, representing one embodiment of this disclosure, illustrates a method for controlling the temperature of a heater region of an electrostatic chuck using a corresponding heater trace integrated in the ESC, the heater trace being configured for temperature sensing and supplying heat to the heater region. The method of flowchart 400 can be applied to… Figure 1 and 2 One or more plasma processing modules 100 and Figures 3A-3C The system described above.

[0075] At step 410, the method includes supplying power from a power source to a heater trace. The heater trace may be integrated into the heater region of the ESC for the plasma processing chamber. The heater trace is configured to provide thermal energy to the heater region. The heater trace may have input and output terminals coupled to the power source, as previously described. The power supplied to the heater trace is controlled by a temperature controller, such as a temperature controller that provides an in-situ (e.g., in an RF thermal environment) measurement of the resistance of the heater trace and correlates that resistance with an approximate temperature of the corresponding heater region.

[0076] At 420, the method includes real-time sensing of the voltage difference between the input and output terminals of the heater trace. Specifically, a temperature controller is configured to sense the input voltage at the input terminal of the heater trace and the output voltage at the output terminal of the heater trace, as previously described. In this way, the voltage drop across the heater trace within the heater region can be determined by the temperature controller. In one embodiment, the sensing of voltage and current is performed within the RF thermal environment of the plasma processing chamber.

[0077] At 430, this method includes real-time current sensing within the heater trace. Specifically, a temperature controller is configured to sense the current through the heater trace, as previously described. Because the current should be equal throughout the circuit containing the heater trace, the current can be sensed at any of multiple nodes within the circuit. For example, the current can be sensed at the input or output of the heater trace, or at a location where a voltage is sensed. Other locations can be used to transmit the current. In one embodiment, current sensing is performed within the RF thermal environment of the plasma processing chamber.

[0078] At 440, the method includes identifying the resistance of the heater trace in real time based on the sensed voltage difference and the sensed current. Specifically, a temperature controller is configured to identify the resistance, as previously described. In one embodiment, the resistance is determined by the relationship between the circuit's voltage (V), current (I), and resistance (R): V = I * R.

[0079] At 450°C, this method includes estimating the temperature of the heater region based on the identified resistance and a correlation function of the heater trace. Specifically, in one embodiment, the determination of the approximate temperature of the heater region does not use a temperature sensor (e.g., a temperature sensor embedded in the layer of the ESC) in the heater region of the ESC, as previously described. The correlation function uses the temperature coefficient of the resistance of the heater trace. In an embodiment, as previously described, the correlation function can be linear or nonlinear.

[0080] In some implementations, the correlation function can be linear, where the temperature coefficient of resistance is constant within a suitable range (e.g., the operating range). The correlation function is defined for a specific heater trace, particularly for heater traces embedded in the ESC. Figure 5 A diagram of correlation function 500 is provided, which defines a linear correlation and / or relationship between the resistance and temperature of a heater trace configured to provide heat to the heater region of an electrostatic chuck. Correlation function 500 uses the temperature coefficient of resistance (TCR) of the heater trace. htr The slope of the correlation function is approximately the temperature coefficient (TCR) of the resistance of the heater trace and / or the heater trace embedded in the ESC. htr In one implementation, the correlation function 500 is calibrated to the heater trace. For example, calibration can be performed at the factory during the manufacturing and / or production of the ESC. Specifically, for a given material, the temperature coefficient of resistance (TCR) is... htr The slope of the line in the correlation function 500 is known. Calibration is performed for a given calibration temperature (e.g., 20 degrees Celsius) and calibration resistance (R). htr@t Q) Provide suitable line intersection points. In this way, relevant functions can be defined for specific heater traces and / or heater traces embedded in the heater region of the ESC.

[0081] In other implementations, the correlation function may be nonlinear. The correlation function can be calibrated for the heater trace itself or for the heater trace embedded in the ESC within a suitable operating temperature range. For example, measurements of the temperature of the heater region and the resistance of the heater trace can be performed to determine a nonlinear correlation function, as previously described, whereby the correlation function defines the relationship between the calibration resistance of the heater trace and the calibration temperature response of the heater region heated by the heater trace.

[0082] In one embodiment, a closed-loop analysis is performed between the approximate temperature of the heater region and the desired temperature of the heater region using a temperature controller. In another embodiment, the closed-loop analysis is performed in situ within the RF thermal environment. In this way, the closed-loop analysis can be used to control the power supplied to the heater track as described above. For example, the temperature controller can iteratively change the power supplied to the heater track to match the approximate temperature of the heater region to the desired temperature over a period of time. In another embodiment, the temperature controller can provide a voltage input defined by a predefined response to a measured approximate temperature of the heater region. In one embodiment, the power supplied to the heater track is controlled using pulse width modulation (PWM). In one embodiment, as described above, in-situ power control is provided for the heater track, wherein the closed-loop analysis is performed within the RF thermal environment of the plasma processing chamber.

[0083] In another embodiment, a user interface is configured to provide information to a user. The user interface may be provided within a display outside the plasma processing chamber. Information may be provided in the user interface, including a first temperature of a first heater region for an electrostatic chuck configured to support a substrate for the plasma processing chamber. The user interface may include a warning providing suggestions, including at least one action to be taken based on the information. Specifically, the first temperature is determined by a first temperature controller configured to: sense a voltage difference across a first heater trace integrated into the first heater region (e.g., between an input and an output of the first heater trace); sense a current within the first heater trace; identify the resistance of the first heater trace based on the sensed voltage difference and the current; and estimate the first temperature based on the resistance and a correlation function of the first heater trace.

[0084] In some implementations, a warning is issued regarding the difference between the desired temperature of the region containing the first heater and a first temperature, where the difference exceeds a threshold.

[0085] In other embodiments, the user interface includes a second temperature of the second heater region of the electrostatic chuck. This second temperature is determined by a second temperature controller configured to: sense a voltage difference across a second heater trace integrated into the second heater region (e.g., between an input and an output of the second heater trace); sense a current within the second heater trace; identify the resistance of the second heater trace based on the voltage difference and the sensed current within the second heater trace; and estimate the second temperature based on the resistance and a correlation function of the second heater trace. In yet another embodiment, the first heater region and the second heater region are located on different horizontal planes.

[0086] In one embodiment, the first temperature controller is configured to provide in-situ control of the power supplied to the first heater track, such that the first temperature controller is located within the RF thermal environment of the plasma processing chamber. Specifically, the first temperature controller performs a closed-loop analysis on the estimated temperature to control the power supplied to the first heater track such that the estimated first temperature matches the desired temperature.

[0087] A1) In one embodiment, a plasma processing system for processing a substrate is disclosed. The plasma processing system includes a reactor comprising an electrostatic chuck (ESC) for supporting the substrate, the reactor being configured to receive process gases. The plasma processing system includes a heater region of the ESC. The plasma processing system includes a heater trace integrated into the heater region. The heater trace is configured to provide heat to the heater region. The heater trace has an input terminal and an output terminal. The plasma processing system includes a temperature controller configured to: sense a voltage difference across the heater trace and sense a current within the heater trace; identify the resistance of the heater trace based on the sensed voltage difference and current; and estimate the temperature of the heater region based on the identified resistance and a correlation function of the heater trace. The correlation function uses a temperature coefficient of the resistance of the heater trace.

[0088] A2) The plasma processing system according to A1, wherein the correlation function is linear or nonlinear.

[0089] A3) The plasma processing system according to A1) wherein the temperature controller performs a closed-loop analysis on the approximate temperature of the heater track to control the power supplied to the heater track so that the approximate temperature matches the desired temperature of the heater region.

[0090] A4) The plasma processing system according to A1), wherein the temperature controller is configured to provide in-situ control of the power supplied to the heater trace, such that the temperature controller is located within the RF thermal environment of the plasma processing chamber.

[0091] A5) The plasma processing system according to A1), wherein the temperature controller estimates the temperature of the heater region without using a temperature sensor in the heater region.

[0092] B1) A plasma processing system for processing a substrate. The plasma processing system includes a first heater region for an electrostatic chuck (ESC) of a plasma processing chamber, wherein the ESC is configured to support the substrate during processing. The ESC includes a first heater trace integrated within the heater region, the first heater trace being configured to provide heat to the first heater region, the first heater trace having a first input and a first output. The plasma processing system includes a first temperature controller configured to sense a first voltage difference across the first heater trace and to sense a first current in the first heater trace. The first temperature controller is configured to identify a first resistance of the first heater trace based on the sensed first voltage difference and the sensed first current. The first temperature controller is configured to estimate a first temperature of the first heater region based on the identified first resistance and a first correlation function of the first heater trace, wherein the first correlation function uses a first temperature coefficient of the resistance of the first heater trace.

[0093] B2) The plasma processing system according to B1), wherein the first correlation function defines a linear correlation between temperature and resistance, and has a slope approximately equal to the temperature coefficient of the resistance of the first heater trace.

[0094] B3) The plasma processing system according to B1), wherein the first correlation function defines a nonlinear correlation between temperature and resistance.

[0095] B4) The plasma processing system according to B1), wherein the first correlation function is defined for the first heater trace integrated in the first heater region of the ESC.

[0096] B5) The plasma processing system according to B1), wherein the first temperature controller estimates the first temperature of the first heater region without using a temperature sensor in the first heater region.

[0097] B6) According to the plasma processing system of B1), the first temperature controller performs a closed-loop analysis on the estimated first temperature of the first heater region to control the power supplied to the first heater trace such that the estimated first temperature matches the desired temperature of the first heater region.

[0098] B7) The plasma processing system according to B6) wherein the first temperature controller uses pulse width modulation to control the power.

[0099] B8) The plasma processing system according to B6) wherein the first temperature controller is configured to provide in-situ control of the power supplied to the first heater trace, such that the first temperature controller is located within the RF thermal environment of the plasma processing chamber.

[0100] B9) The plasma processing system according to B1) includes a second heater region and a second heater trace integrated within the second heater region of the ESC. The second heater trace is configured to provide thermal energy to the second heater region and has a second input terminal and a second output terminal. The plasma processing system includes a second temperature controller configured to: sense a second voltage difference across the second heater trace and sense a second current in the second heater trace; identify a second resistance of the second heater trace based on the sensed second voltage difference and the sensed second current; and estimate a second temperature of the second heater region based on the identified second resistance and a second correlation function of the second heater trace, wherein the second correlation function uses a second temperature coefficient of the resistance of the second heater trace.

[0101] B10) The plasma processing system according to B9) wherein the first heater region and the second heater region are on different horizontal planes.

[0102] B11) According to the plasma processing system of B1), the horizontal width of the cross-section of the first heater trace is less than 10 mm.

[0103] Figure 6 A control module 600 for controlling the aforementioned system is shown. In one embodiment, Figure 1 Control module 110 and / or Figure 2 The 200 may include some exemplary components of the control module 600. For example, the control module 600 may include a processor, memory, and one or more interfaces. The control module 600 can be used to control devices in the system in part based on sensed values. By way of example only, the control module 600 may control one or more of valve 602, filter heater 604, pump 606, heater region 320, and other devices 608 based on sensed values ​​and other control parameters. By way of example only, the control module 600 receives sensed values ​​from pressure gauge 610, flow meter 612, and / or other sensors 616. The control module 600 can also be used to control process conditions during membrane precursor delivery and deposition. The control module 600 will typically include one or more storage devices and one or more processors.

[0104] Control module 600 controls the activities of the precursor delivery system and deposition apparatus. Control module 600 executes a computer program including a set of instructions for controlling process timing, delivery system temperature, and pressure differential across filters, valve positions, gas mixing, chamber pressure, chamber temperature, substrate temperature, RF power levels, substrate chuck or pedestal positions, and other process-specific parameters. Control module 600 can also monitor pressure differentials and automatically switch the gaseous precursor delivery from one or more paths to one or more other paths. In some embodiments, additional computer programs stored in a memory device associated with control module 600 may be used.

[0105] The control module 600 can be configured to sense voltage, sense current, determine resistance, determine the temperature of the heater region, and control the power supplied to the heater region 320 based on the sensed voltage and current. Specifically, the control module 600 can be configured to determine an approximate temperature of the corresponding heater region in the ESC, wherein this approximate temperature can be determined by resistance measurements of the corresponding heater trace used to heat the heater region (e.g., by sensing voltage and current) and by using a correlation function of the heater trace's resistance temperature coefficient. The control module 600 can be configured to analyze the approximate temperature for a desired temperature and specify the voltage to be applied to the heater trace in response.

[0106] Typically, a user interface will exist associated with the control module 600. The user interface may include a display 618 (e.g., a display screen and / or graphical software display of apparatus and / or process conditions) and a user input device 620, such as a pointing device, keyboard, touch screen, microphone, etc.

[0107] Computer programs used to control the transport, deposition, and other processing in the process sequence of precursors can be written in, for example, any of the following conventional computer-readable programming languages: assembly language, C, C++, Pascal, Fortran, or others. The compiled object code or script is executed by the processor to perform the tasks identified in the program.

[0108] The control module parameters relate to process conditions, such as, for example, filter pressure differential, process gas composition and flow rate, temperature, pressure, plasma conditions (e.g., RF power level and low-frequency RF frequency), cooling gas pressure, and chamber wall temperature.

[0109] System software can be designed or configured in many different ways. For example, various chamber component subroutines or control objects can be written to control the operation of chamber components necessary for the deposition process of this invention. Examples of programs or program segments used for this purpose include substrate positioning code, process gas control code, pressure control code, heater control code, and plasma control code.

[0110] The substrate positioning procedure may include program code for controlling chamber components used to load the substrate onto a pedestal or chuck and to control the spacing between the substrate and other chamber components (e.g., gas inlets and / or targets). The process gas control procedure may include code for controlling gas composition and flow rate, and optionally for allowing gas to flow into the chamber prior to deposition to stabilize the pressure within the chamber. The filter monitoring procedure includes code for comparing one or more measured differences with one or more predetermined values ​​and / or for switching paths. The pressure control procedure may include code for controlling the pressure within the chamber by adjusting, for example, a throttle valve in the chamber's exhaust system. The heater control procedure may include code for controlling the current supplied to a heating unit used to heat components within the precursor delivery system, the substrate, and / or other parts of the system. Alternatively, the heater control procedure may control the delivery of a heat transfer gas (e.g., helium) to the substrate chuck.

[0111] Examples of sensors that can be monitored during deposition include, but are not limited to, mass flow control modules, pressure sensors such as pressure gauge 610, and thermocouples located in the transfer system, base, or chuck. Appropriately programmed feedback and control algorithms can be used in conjunction with data from these sensors to maintain the desired process conditions. The foregoing describes embodiments of the invention implemented in single-chamber or multi-chamber semiconductor processing tools.

[0112] In some implementations, the controller is part of a system, which may be part of the examples described above. Such a system may include semiconductor processing apparatus, which includes one or more processing tools, one or more chambers, one or more platforms for processing, and / or specific processing components (substrate pedestals, gas flow systems, etc.). These systems may be integrated with electronics for controlling their operation before, during, and after the processing of semiconductor wafers or substrates. The electronics may be referred to as a “controller”, which can control various components or sub-components of one or more systems. Depending on the processing requirements and / or system type, the controller may 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, substrate transfer tools and other transfer tools, and / or loading locks connected to or interfaced with a specific system.

[0113] In general, a controller can be defined as an electronic device having various integrated circuits, logic, memory, and / or software for receiving instructions, issuing instructions, controlling operations, enabling cleaning operations, enabling endpoint measurements, etc. Integrated circuits can 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 can be instructions sent to the controller in the form of various individual settings (or program files), defining operating parameters for performing specific processes on or against a semiconductor wafer or system. In some embodiments, the operating parameters can be part of a recipe defined by a process engineer, the process being designed to complete one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silica, surfaces, circuits, and / or wafer dies.

[0114] In some implementations, the controller may be part of or coupled to a computer integrated with, coupled to, or otherwise networked to the system. For example, the controller may be in the “cloud” or be all or part of a fab host system, allowing remote access to substrate 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 criteria of multiple manufacturing operations, change parameters of the current process, set processing steps to follow the current process, or initiate a new process. In some examples, a remote computer (e.g., a server) may provide processing recipes 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.

[0115] In some examples, the controller receives instructions in the form of data specifying parameters for each processing step to be performed during one or more operations. It should be understood that the parameters can be specific to the type of processing to be performed and the type of tool to which the controller is configured to interface with or control the tool. Thus, as described above, the controller can be distributed, for example, by including one or more discrete controllers networked together and working toward a common purpose (such as the processing and control described herein). An example of a distributed controller for such a purpose is one or more integrated circuits on a room communicating with one or more integrated circuits remotely (e.g., at the platform level or as part of a remote computer), which together control processing on the room.

[0116] Example systems may include, but are not limited to, plasma etching chambers or modules, deposition chambers or modules, rotary rinsing chambers or modules, metal plating chambers or modules, cleaning chambers or modules, chamfering edge etching 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 etching (ALE) chambers or modules, ion implantation chambers or modules, orbital chambers or modules, and any other semiconductor processing systems that may be associated with or used in the manufacture and / or preparation of semiconductor wafers.

[0117] As described above, depending on one or more processing steps to be performed by the tool, the controller may 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 plant, a host computer, another controller, or tools used in the transport of materials to and from the tool location and / or loading port in the semiconductor manufacturing plant.

[0118] The foregoing description of the embodiments is provided for illustrative and descriptive purposes. It is not intended to exhaustively detail or limit the invention. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but are interchangeable and usable in selected embodiments where applicable, even if not specifically shown or described. This can also be varied in various ways. Such variations are not considered to depart from the invention, and all such modifications are included within the scope of the invention.

[0119] While the foregoing embodiments have been described in considerable detail for clarity, it should be understood that certain changes and modifications may be implemented within the scope of the appended claims. Therefore, these embodiments should be considered illustrative rather than restrictive, and these embodiments should not be limited to the details provided herein, but may be modified within the scope of their claims and equivalents.

Claims

1. A controller comprising: A voltage sensor coupled to a heater trace integrated in an electrostatic chuck, the voltage sensor being configured to sense the voltage difference across the heater trace, wherein the heater trace is associated with a heater region. A current sensor, coupled to the heater trace, is configured to sense the current in the heater trace; A resistance identifier is configured to identify the resistance of the heater trace based on the voltage difference and the sensed current; A temperature correlator is configured to estimate the temperature of the heater region based on the resistance and a correlation function of the heater trace; as well as A power controller is configured to adjust the power supplied to the heater trace based on a comparison between the estimated temperature and a desired temperature associated with the heater region. The correlation function uses the temperature coefficient of the resistance of the heater trace. The controller is located within the RF thermal environment of the plasma processing chamber, and The controller is used to provide in-situ regulation of the power supplied to the heater trace.

2. The controller according to claim 1, further comprising: A temperature comparator is configured to compare the estimated temperature with the desired temperature associated with the heater region.

3. The controller according to claim 1, The power controller uses pulse width modulation to regulate the power.

4. The controller according to claim 1, The power controller performs a closed-loop analysis of the estimated temperature to adjust the power supplied to the heater trace so that the estimated temperature matches the desired temperature.

5. The controller of claim 1, wherein the temperature correlator estimates the temperature without using a temperature sensor.

6. A user interface device comprising: The display is configured to show information related to the first heater area of ​​the electrostatic chuck in the plasma processing chamber; The information includes a first temperature associated with the first heater region; The first temperature is determined by a first temperature controller, which is configured to: Sensing the voltage difference across the first heater trace associated with the first heater region; Sensing the current within the first heater trace; The resistance of the first heater trace is identified based on the voltage difference and the sensed current; as well as The first temperature is estimated based on the resistance and the correlation function of the first heater trace. The first temperature controller is located within the RF thermal environment of the plasma processing chamber, and the first temperature controller is configured to provide in-situ regulation of the power supplied to the first heater trace.

7. The user interface device according to claim 6, further comprising: The logic is configured to trigger an alert based on the first temperature.

8. The user interface device according to claim 7, The warning includes a suggestion that provides at least one action to be taken based on the information.

9. The user interface device of claim 7, wherein the warning is triggered when the difference between the desired temperature of the first heater region and the first temperature exceeds a threshold.

10. The user interface device according to claim 6, The information mentioned therein includes a second temperature associated with the second heater region of the electrostatic chuck.

11. The user interface device of claim 10, wherein the second temperature is determined by a second temperature controller, the second temperature controller being configured to: Sensing the voltage difference across the second heater trace associated with the second heater region; Sensing the current in the second heater trace; The resistance of the second heater trace is identified based on the voltage difference within the second heater trace and the current sensed within the second heater trace; and The second temperature of the second heater region is estimated based on the resistance and the correlation function of the second heater trace.

12. The user interface device according to claim 10, wherein the first heater region and the second heater region are on different horizontal planes.

13. The user interface device of claim 6, wherein the first temperature controller is further configured to compare the first temperature with a desired temperature associated with the first heater region.

14. The user interface device according to claim 13, The first temperature controller is further configured to adjust the power supplied to the first heater trace based on a comparison between the first temperature and the desired temperature.

15. The user interface device according to claim 9, The first temperature controller performs a closed-loop analysis of the first temperature to adjust the power supplied to the first heater trace so that the first temperature matches the desired temperature.

16. A method for controlling the temperature of an electrostatic chuck in a plasma processing chamber, the electrostatic chuck including a heater region having a heater track integrated therein, the heater track having an input end and an output end and configured to provide thermal energy to the heater region, the method comprising: Power is supplied to the heater trace; The voltage difference between the input and output terminals of the heater trace is sensed; Sensing the current in the heater trace; The resistance of the heater trace is identified based on the sensed voltage difference and the sensed current; The temperature of the heater region is estimated based on the identified resistance and the correlation function of the heater trace, without using a temperature sensor in the heater region, wherein the correlation function uses the temperature coefficient of the resistance of the heater trace; Perform a closed-loop analysis of the estimated temperature of the heater region and the desired temperature associated with the heater region; Based on the closed-loop analysis, pulse width modulation is used to adjust the power supplied to the heater trace; as well as In-situ control of the power supplied to the heater trace is provided by performing the closed-loop analysis within the RF thermal environment of the plasma processing chamber.

17. The method of claim 16, further comprising: Compare the estimated temperature of the heater region with the expected temperature associated with the heater region.

18. The method of claim 17, further comprising: An alert is generated when the comparison between the estimated temperature and the desired temperature associated with the heater region exceeds a threshold.

19. The method of claim 17, further comprising: This displays a comparison between the estimated temperature and the desired temperature associated with the heater region.

20. The method of claim 17, further comprising: The power supplied to the heater trace is adjusted based on a comparison between the estimated temperature and the desired temperature associated with the heater region.

21. The method of claim 17, further comprising: The power supplied to the heater trace is adjusted so that the estimated temperature matches the desired temperature associated with the heater region.

22. The method of claim 17, wherein the correlation function defines a linear correlation between temperature and resistance and has a slope for the temperature coefficient of the resistance of the heater trace.

23. The method of claim 17, wherein the correlation function defines a nonlinear correlation between temperature and resistance.

24. The method of claim 17, wherein the correlation function is defined for the heater trace integrated in the heater region.

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