Electrostatic Chuck Heater Resistance Measurements to Approximate Temperature

Abstract

The controller includes a voltage sensor coupled to a heater trace integrated into the electrostatic chuck, the voltage sensor configured to sense a voltage difference across the heater trace, the heater trace 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 approximate a temperature of the heater zone based on the resistance of the heater trace and a correlation function. The correlation function uses a resistance temperature coefficient of the heater trace.

Description

[Technical field]

[0001] The present embodiments relate to electrostatic chucks (ESCs) useful for processing substrates such as semiconductor wafers. The ESCs may be used to support the semiconductor substrate in a plasma reaction chamber in which an etching or deposition process is performed. In particular, the present embodiments relate to measuring the resistance of a heater trace in a heater zone of the ESC to approximate the temperature of the heater zone without using a temperature sensor in the heater zone of the ESC. [Background technology]

[0002] Many modern semiconductor manufacturing processes are carried out in plasma processing modules in which a substrate is held in a substrate holder when exposed to the plasma. Temperature control of the substrate during a plasma processing operation is one factor that can affect the outcome of the processing operation. To provide control of the substrate temperature during a plasma processing operation, the temperature of the substrate holder must be accurately and reliably measured to infer the temperature of the substrate held thereon.

[0003] The discussion of the background art provided herein is intended to present the contents of the present disclosure generally, and the inventions of the presently listed inventors are not admitted expressly or impliedly as prior art to the present disclosure, to the extent that they are described in this Background section, or in aspects of the description that are not prior art at the time of filing.

[0004] It is against this background that embodiments of the present disclosure arise. Summary of the Invention

[0005] The present embodiments relate to solving one or more problems found in the related art, and in particular to providing an electrostatic chuck for a plasma processing chamber. The ESC includes a heater trace in a heater zone thereof, the heater trace being configured to sense a temperature by a determined resistance thereof. Several inventive embodiments of the present disclosure are described below.

[0006] An embodiment of the disclosure includes a controller comprising a voltage sensor coupled to a heater trace integrated into an electrostatic chuck, the voltage sensor configured to sense a voltage difference across the heater trace, the heater trace associated with a heater zone. The controller comprises a current sensor coupled to the heater trace and configured to sense a current in the heater trace. The controller comprises a resistance identifier configured to identify a resistance of the heater trace based on the voltage difference and the sensed current. The controller comprises a temperature correlator configured to approximate a temperature of the heater zone based on the resistance of the heater trace and a correlation function. The correlation function uses a resistance temperature coefficient of the heater trace.

[0007] Another embodiment of the present disclosure includes a user interface configured to provide information to a user. The user interface may be provided on a display device outside the plasma processing chamber. The display device is configured to show information about a first heater zone of an electrostatic chuck for the plasma processing chamber. The information includes a first temperature associated with the first heater zone. 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 zone. The first temperature controller is configured to sense a current of the first heater trace. The first temperature controller is configured to identify a resistance of the first heater trace based on the voltage difference and the sensed current. The first temperature controller is configured to approximate the first temperature based on the resistance of the first heater trace and a correlation function.

[0008] The user interface may include an alert that provides a recommendation 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 of a first heater trace integrated into the first heater zone, sense a current of the first heater trace, identify a resistance of the first heater trace based on the voltage difference and the sensed current, and approximate the first temperature based on the resistance of the first heater trace and a correlation function.

[0009] An embodiment of the disclosure includes an electrostatic chuck (ESC) for a plasma processing chamber configured to support a substrate during processing. The ESC comprises a first heater zone. The ESC comprises a first heater trace integrated into the heater zone and configured to provide heat to the first heater zone. The first heater trace has a first input end and a first output end. A first temperature controller is configured to approximate a temperature of the first heater zone. The temperature controller is configured to sense a first voltage difference of the first heater trace and sense a first current of 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 approximate a first temperature of the first heater zone based on the identified first resistance of the first heater trace and a first correlation function, the first correlation function using a first resistance temperature coefficient of the first heater trace.

[0010] Another embodiment of the present disclosure includes a method for controlling a temperature of an electrostatic chuck (ESC) of a plasma processing chamber having a heater zone with an integrated heater trace. The heater trace has an input end and an output end and is configured to provide heat to the heater zone. The method includes providing power to the heater trace. The method includes sensing a voltage difference across the heater trace (e.g., between an input end and an output end of the heater trace). The method includes sensing a current across the heater trace. The method includes identifying a resistance of the heater trace based on the sensed voltage difference and the sensed current. The method includes approximating a temperature of the heater zone based on the identified resistance and a correlation function of the heater trace without using a temperature sensor in the heater zone, the correlation function using a resistance temperature coefficient of the heater trace.

[0011] Yet another embodiment of the present disclosure includes a plasma processing system for substrate processing. The plasma processing system includes a reactor configured to receive a process gas, the reactor including an electrostatic chuck (ESC) for supporting a substrate. The ESC includes a heater zone. The ESC further includes a heater trace integrated into the heater zone. The heater trace is configured to provide heat to the heater zone and includes an input end and an output end. The plasma processing system includes a temperature controller coupled and configured to sense a voltage difference between the input end and the output end of the heater trace and to sense a current in the heater trace. The temperature controller is configured to identify a resistance of the heater trace based on the sensed voltage difference and the sensed current. The temperature controller is configured to approximate a temperature of the heater zone based on the identified resistance and a correlation function of the heater trace, the correlation function using a resistance temperature coefficient of the heater trace.

[0012] These and other advantages will be apparent to those of ordinary skill in the art upon reading the entire specification and claims. [Brief description of the drawings]

[0013] The present embodiments will be best understood with reference to the following description taken in conjunction with the accompanying drawings.

[0014] [Figure 1] 1 illustrates a substrate processing system used to process wafers (eg, form a film thereon) according to one embodiment of the present disclosure.

[0015] [Diagram 2] FIG. 1 is a system diagram of a reactor used for processing semiconductor substrates according to one embodiment of the present disclosure, the reactor comprising an electrostatic chuck having one or more heater zones heated by one or more heater traces each configured to sense temperature, the heater traces being controlled by one or more in situ temperature controllers.

[0016] [Figure 3A] FIG. 1 illustrates a vertical cross-sectional view of an exemplary substrate holder configured as an electrostatic chuck with one or more heater zones heated by one or more heater traces each configured to sense temperature, according to one embodiment of the present disclosure.

[0017] [Figure 3B] 3B, according to one embodiment of the present disclosure, a heating system configured to provide heat to a particular heater zone of the electrostatic chuck of FIG. 3A, wherein a temperature controller controls a temperature of the heater zone as measured by a corresponding heater trace also configured to provide heat.

[0018] [Figure 3C] A power controller of the temperature controller of FIG. 3B configured to control the power provided to the heater traces to control the temperature of the heater zone, according to one embodiment of the disclosure.

[0019] [Figure 4]FIG. 2 is a flow diagram illustrating a method for measuring a temperature of a temperature zone of an electrostatic chuck using corresponding heater traces configured to sense the temperature and provide heat to the heater zone, in accordance with one embodiment of the present disclosure.

[0020] [Diagram 5] FIG. 2 is a diagram of a correlation function between the resistance and temperature of a heater trace configured to provide heat to a heater zone of an electrostatic chuck, the correlation function using the resistance temperature coefficient of the heater trace, in accordance with one embodiment of the present disclosure.

[0021] [Figure 6] A control module for controlling the above system according to one embodiment of the present disclosure. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] Although the following detailed description includes many specific details for purposes of illustration, one of ordinary skill in the art will appreciate that many variations and alterations to the following details are within the scope of the disclosure. Accordingly, the aspects of the disclosure described below are set forth without loss of generality to, and without imposing limitations on, the claims that follow this description.

[0023] Generally, various embodiments of the present disclosure describe systems and methods for determining an approximate temperature of a corresponding heater zone of an electrostatic chuck (ESC) by a correlation function using a resistance measurement of the corresponding heater trace used to heat the heater zone and the resistance temperature coefficient of the heater trace. Because embodiments of the present disclosure do not require a dedicated temperature probe and / or sensor to be inserted into a cutout in a layer of the ESC (where the cutout would otherwise be provided for placement of the sensor), the ESC itself can be thinner than a conventional ESC.

[0024] Additionally, embodiments of the present disclosure provide improved radio frequency (RF) uniformity across the surface of the ESC because the ESC ceramic does not have cutouts, holes, etc. for direct temperature sensing required in conventional ESCs configured for temperature measurement.

[0025] Additionally, the ESC heating control system of the disclosed embodiments may be implemented more economically and at a significantly lower cost than previous systems due to the absence of a requirement for direct temperature sensor components embedded in the ESC (i.e., no fiber optic sensors, bandgap sensors, etc.).

[0026] Additionally, the ESC heating system of the disclosed embodiments does not require the use of temperature sensors as in previous heating systems and can therefore operate at higher temperatures (e.g., greater than 150° C.) without having to consider the heating limitations of those temperature sensors used to directly sense the heater zone of the ESC in previous systems (e.g., bandgap sensors can operate up to 150° C.).

[0027] Furthermore, compared to previous heating control systems that provide open-loop control of the temperature of the heater zone outside the RF hot boundary due to less accurate temperature measurements, embodiments of the present disclosure provide more accurate temperature measurements, thereby allowing in situ (e.g., within the RF hot boundary) closed-loop control of the heating trace.

[0028] Also, because there is no requirement on the thickness of the heater trace used to heat the heater zone of the ESC when measuring voltage and current to determine temperature, the heater trace can be arbitrarily thin and still be configured to measure voltage and current to determine the temperature of the heater trace and closely approximate the temperature of the heater zone in embodiments of the present disclosure.

[0029] Furthermore, embodiments of the present disclosure can provide a high degree of process control when providing heat to multiple heater zones of an ESC because many more heater zones (e.g., individually controlled vertical heater traces distributed throughout the ESC) can be configured inside the ESC due to the closed-loop control of the heater traces allowing these heater traces to be arbitrarily thin, compared to conventional heater systems that have a limited number of heater zones due to the space required for temperature sensors and the low resolution of the temperature relationship between the heater traces and corresponding heater zones due to the low thermal conductivity of the ESC ceramics.

[0030] Additionally, embodiments of the present disclosure are configured to provide more accurate temperature measurements of the heater zones because by measuring the resistance of the heater traces within the heater zones instead of sensing the temperature of the ceramic of the heater zones, the measurements are less susceptible to thermal crosstalk or leakage between zones as is the case with conventional temperature sensing systems.

[0031] Embodiments of the present disclosure relate to plasma processing modules (e.g., those used in plasma etch chambers or modules, deposition chambers or modules, spin rinse chambers or modules, metal plating chambers or modules, cleaning chambers or modules, bevel edge etch chambers or modules, physical vapor deposition (PVD) chambers or modules, chemical vapor deposition (CVD) chambers or modules, atomic layer deposition (ALD) chambers or modules, plasma enhanced chemical vapor deposition (PECVD) chambers or modules, atomic layer etching (ALE) chambers or modules, ion implantation chambers or modules, track chambers or modules, and other semiconductor processing systems that may be related to or used in the fabrication and / or manufacture of semiconductor wafers, including processes such as electroplating, electrolytic etching, electropolishing, electrochemical mechanical polishing, deposition, wet deposition, and through silicon via (TSV) processes). Furthermore, embodiments of the present disclosure are not limited to the examples described herein and may be performed in different plasma processing systems using different configurations, geometries, and plasma generation techniques (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 No. 15 / 369,110, all of which are incorporated by reference in their entirety. Importantly, the plasma processing module of the disclosed embodiment includes an electrostatic chuck configured to support a substrate, and the approximate temperature of the corresponding heater zone of the ESC can be determined by resistance measurements of the corresponding heater traces used to heat the heater zone and a correlation function of the heater traces with the resistance temperature coefficients of the heater traces. The temperature determination of the heater zone by the resistance measurements of the corresponding heater traces and the corresponding correlation function may be applied to heating assemblies other than the heating assembly configured to support a substrate.For example, in other embodiments, the heating assembly may comprise a showerhead, an ESC, a support chuck, a pedestal, a chamber part, or other structure or component that may be implemented in a reactor, chamber, process module, etc. used to process a substrate.

[0032] Throughout this specification, the term "substrate" as used herein refers to a semiconductor wafer in the embodiments of the present disclosure. However, in other embodiments, the term substrate refers to a substrate formed of sapphire, GaN, GaAs, or SiC, or other substrate materials, and can include glass panels / substrates, metal foils, metal sheets, polymeric materials, and the like. Also, in various embodiments, the substrates described herein can vary in form, shape, and / or size. For example, in some embodiments, the substrates described herein can correspond to 200 mm (millimeter) semiconductor wafers, 300 mm semiconductor wafers, or 450 mm semiconductor wafers. Also, in some embodiments, the substrates described herein can correspond to non-circular substrates, such as rectangular substrates for flat panel displays, and can include other shapes.

[0033] With the above various embodiments generally understood, illustrative details of the present embodiments will now be described with reference to the various drawings. Elements and / or components with the same number in one or more figures are generally intended to have the same structure and / or function. Moreover, the figures are not drawn to scale, but are intended to illustrate and emphasize novel concepts. It will be apparent that the present embodiments may be practiced without some or all of these specific details. In other instances, well-known process operations have not been described in detail so as not to unnecessarily obscure the present embodiments.

[0034] FIG. 1 illustrates a reactor system 100 that may be used to deposit a film on a substrate, such as a substrate formed in an atomic layer deposition (ALD) process. These reactors may use one or more heaters, and in this example reactor, a common terminal structure may be used to control the temperature for uniformity or custom settings. More specifically, FIG. 1 illustrates a substrate processing system 100 that may be used to process a wafer 101. The system includes a chamber 102 having an upper chamber portion 102a and a lower chamber portion 102b. A support post 160 is configured to support a pedestal 140, which in one embodiment is a powered electrode. The pedestal 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 input controls 108. The process input controls 108 may include a process recipe, such as power levels, timing parameters, process gases, mechanical motion of the wafer 101 (eg, depositing or forming a film on the wafer 101), and the like.

[0035] The pedestal 140 includes an electrostatic chuck (ESC) 310 configured to hold the substrate 101 exposed to a plasma processing environment in which a plasma is generated. An embodiment of the present disclosure provides for determination and / or measurement of one or more heater zones of the ESC 310 during plasma processing operations in the reactor system 100. In particular, an approximate temperature of a corresponding heater zone is determined by a resistance measurement of a corresponding heater trace used to heat the heater zone and a correlation function of the heater trace with the resistance temperature coefficient of the heater trace.

[0036] The support columns 160 also include lift pins (not shown), each of which is actuated by a corresponding lift pin actuation ring 120 controlled by a lift pin control 122. The lift pins are used to lift the wafer 101 off the pedestal 140 so that the end effector can pick it up, and to lower the wafer 101 after placement by the end effector. The substrate processing system 100 further includes a gas supply manifold 112 coupled to a process gas section 114 (e.g., a gas chemical supply from the facility). Depending on the process being performed, the control module 110 controls the supply of process gases 114 through the gas supply manifold 112, the chamber pressure, the generation of RF power from one or more RF sources, exhaust pumps, etc. The selected gas is then flowed to a showerhead 150 and distributed to a spatial volume defined between a surface of the showerhead 150 facing the wafer 101 and the wafer 101 resting on the pedestal 140. In an ALD process, the gas may be a reactant selected for absorption or for reaction with an absorbed reactant.

[0037] Additionally, the gases may or may not be premixed. Appropriate valve and mass flow control mechanisms may be used to ensure that the correct gases are delivered during the deposition and plasma treatment stages of the process. The process gases exit through an outlet. A vacuum pump (e.g., a single or two-stage mechanical dry pump and / or a turbomolecular pump) draws the process gases and maintains a suitable low pressure in the reactor by a closed-loop controlled flow restriction device (e.g., a throttle valve or pendulum valve).

[0038] Also shown in the figure is a carrier ring 175 that surrounds an outer region of the pedestal 140. The carrier ring 175 is configured to be positioned at a carrier ring support area one level below the central wafer support area of ​​the pedestal 140. The carrier ring 175 includes an outer edge side (e.g., outer diameter) of its disk structure and a wafer edge side (e.g., inner diameter) of its disk structure that is closest to where the wafer 101 is located. The wafer edge side of the carrier ring 175 includes a plurality of contact support structures configured to lift the wafer 101 when the carrier ring 175 is lifted by the spider forks 180. Thus, the carrier ring 175, along with the wafer 101, can be lifted and cycled to another station (e.g., in a multi-station system). In other embodiments, the chamber is a single station chamber.

[0039] Further, the in situ heater temperature controller 200 is configured to control the temperature of one or more heater zones of the ESC 310 of the pedestal 140. The heater zones are used to enable precise control of the surface temperature of the ESC 310 during substrate processing. The controllable heater zones provide the ability to adjust the temperature profile (e.g., radial profile) of the ESC 310 to compensate for changing environmental conditions (e.g., heat loss conditions, heat transfer conditions, etc. that change between different process steps). In one embodiment, the in situ heater temperature controller 200 may operate independently in a closed loop configuration with the heater traces of the corresponding heater zones. In another embodiment, the in situ heater temperature controller 200 may cooperate with the controller 110 in a closed loop configuration with the heater traces of the corresponding heater zones. In an embodiment, the in situ temperature controller 200 is installed inside the chamber 102. In other embodiments, there may be multiple temperature controllers installed both inside and outside the chamber 102, as described below.

[0040] 2 shows a schematic diagram of a reactor system 100 used to process semiconductor substrates according to one embodiment of the disclosure, the reactor system 100 including a chamber 102 with a pedestal 140 having an ESC 310, the ESC 310 including one or more heater zones heated by one or more heater traces each configured to sense temperature, the heater traces controlled by one or more in situ temperature controllers. A semiconductor substrate 101 is shown disposed on the pedestal 140. A showerhead 150 is used to supply process gases used to form and generate plasma in the chamber 102. A gas supply 114 supplies one or more gases depending on the process recipe being implemented. A controller 110 is used to provide instructions to various components of the reactor system 100, including equipment such as the gas supply 114, pressure controls, temperature controls, and other process parameters.

[0041] The ESC 310 of the pedestal 140 may also be configured with one or more heater zones that, in one embodiment, 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 zones of the ESC 310. The in situ temperature controllers 200 are located within the chamber 102 and thus within the RF hot boundary such that each in situ temperature controller 200 is exposed to process conditions (e.g., high temperature, high pressure, etc.). In an embodiment, the one or more heater zones of the ESC 310 may be controlled by one or more in situ temperature controllers and / or controller 110. That is, each heater zone may be controlled (1) independently by one or more in situ temperature controllers 200, (2) individually by controller 110 (i.e., located outside the RF hot boundary), or (3) by a combination of the 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 advantageous for a variety of reasons, including, but not limited to, providing backup in case of controller failure, precise control by placing temperature controllers in more than one location, and greater efficiency by assigning different controllers to different heater zones.

[0042] By way of example only, the ESC 310 may be configured with two heater zones: an inner heater zone heated by a heater trace R-in (e.g., a resistive element) and an outer heater zone heated by a heater trace R-out (e.g., a resistive element). The heater power supply 240A is configured to supply power to the inner heater zone disposed on the ESC 310. The heater power supply 240B is configured to supply power to the outer heater zone disposed on the ESC 310. In an embodiment, the in situ temperature controller 200, the controller 110, or a combination thereof is coupled to the heater power supply 240A and the heater power supply 240B to control the temperature in the inner heater zone and the outer heater zone by controlling the power supplied to the heater trace R-in and the heater trace R-out. For example, in one embodiment, the in situ temperature controller 200 may be coupled to the heater power supply 240A and the heater power supply 240B in a closed loop configuration to control the temperature in the inner heater zone and the outer heater zone. In another embodiment, the controller 110 may be coupled to the heater power supply 240A and the heater power supply 240B in a closed loop configuration to control the temperature in the inner heater zone and the outer heater zone. In yet another embodiment, the in situ temperature controller 200 and / or the controller 110 are coupled to the heater power supply 240A and the heater power supply 240B in a closed loop configuration to control the temperature in the inner heater zone and the outer heater zone. For clarity and brevity, various embodiments herein are described as having one or more heater zones of the ESC 310 controlled by the in situ temperature controller 200A, although it is understood that the heater zones may in other embodiments be controlled by either the in situ temperature controller 200A and / or the controller 110, or various combinations.

[0043] Specifically, the functionality of the in situ controller 200 provides a resistance measurement of a corresponding heater trace used to heat the corresponding heater zone, the resistance measurement being determined by one or more voltage and current measurements. An approximate temperature of the corresponding heater zone is then determined using the resistance measurement of the heater trace and a correlation function, the correlation function using the resistance temperature coefficient of the heater trace. In a closed loop configuration, the determined approximate temperature of the heater zone may be used to determine the power provided to the corresponding heater zone. For example, if the approximate temperature of the corresponding heater zone is lower than a desired temperature, more power may be provided to the heater trace to increase the temperature of that heater zone. On the other hand, if the approximate temperature of the corresponding heater zone is higher than a desired temperature, less power may be provided to the heater trace to decrease the temperature of that heater zone. Specifically, a heater power supply 240A may be coupled to the inner heater zone, and a heater power supply 240B may be coupled to the outer heater zone. In general, heater power supply 240A can provide a voltage V-in to heater trace R-in to affect a change in temperature of the inner heater zone. Similarly, heater power supply 240B can provide a voltage V-out to heater trace R-out to affect a change in temperature of the outer heater zone.

[0044] 3A is a vertical cross-sectional view of an exemplary substrate holder configured as an electrostatic chuck with one or more heater zones heated by one or more heater traces each configured to sense temperature, according to one embodiment of the present disclosure. In particular, the substrate holder may be an ESC 310 or other type of substrate support member. For brevity and clarity, the substrate holder is described herein as an electrostatic chuck.

[0045] The ESC 310 may be the top layer of the pedestal 140. The ESC 310 may also include a base plate, a bond layer disposed on the base plate, and a ceramic layer disposed on the bond layer, where the bond layer secures the ceramic layer to the base plate. For simplicity and clarity, the base plate, bond layer, and ceramic layer are not shown. The ceramic layer may include one or more layers. The top surface of the ESC 310 may include an area configured to support the substrate 101 during processing.

[0046] The ESC 310 may include one or more clamp electrodes (not shown) coupled to a clamp voltage power supply (not shown) for clamping the supported substrate to the ESC 310. In some embodiments, a single electrode may be configured to create an electric field to hold the substrate 101 to the ceramic layer. In other embodiments, two or more clamp electrodes may be configured to generate different voltages between the electrodes, which in turn create an electric field to hold the substrate 101 to the ceramic layer.

[0047] As shown, the ESC 310 includes one or more heater zones. For example, the ESC 310 may include multiple heater zones, heater zone 1 (320-A), heater zone 2 (320-B) through heater zone N (320-N), and each heater zone may be individually controlled (e.g., one heater zone may be controlled independently from another heater zone). In one embodiment, the heater zones are located in the same horizontal plane. In another embodiment, the heater zones may be located in different horizontal planes, such that a first heater zone and a second heater zone are located in different horizontal planes. Each heater zone may include a heater trace (e.g., a resistive element) electrically coupled to a controller for controlling power provided to the corresponding heater trace (e.g., power provided by a corresponding heater power supply (not shown)). Each heater trace may be integrated or embedded in the corresponding heater zone and configured to provide heat to the corresponding heater zone. For example, the heater traces may be fabricated and formed within the ceramic layer of the ESC 310 such that the heater traces are disposed within the ceramic layer. Thus, heat generated by the heater traces may be transferred to the ceramic layer. Each heater trace has an input end and an output end. Each heater trace may be controlled by a corresponding in situ temperature controller 200. For example, the corresponding in situ temperature controller 200 may be coupled between the input end of the corresponding heater trace and the output end of that heater trace. As previously mentioned, the controller may be the in situ temperature controller 200, the controller 110, or a combination thereof. For example, heater zone 1 is coupled to in situ temperature controller A (200A) through input line 305A (e.g., coupled to the input end of heater trace 1) and output line 307A (e.g., coupled to the output end of heater trace 1). That is, in situ temperature controller A (200A) is coupled between the input end and the output end of heater trace 1 of heater zone 1 (320-A).Also, in situ temperature controller B (200B) is coupled between an input end (e.g., via input line 305B) and an output end (e.g., via output line 307B) of heater trace 2 of heater zone 2 (320-B). The other heater traces are similarly controlled with in situ temperature controller N (200N) coupled between an input end (e.g., via input line 305N) and an output end (e.g., via output line 307N) of heater trace N of heater zone N (320-N). In an embodiment, one or more in situ temperature controllers 200 may be used to control one or more heater zones such that each heater zone may be controlled in a one-to-one relationship with a corresponding in situ temperature controller 200, or such that fewer in situ temperature controllers 200 than the number of heater zones may be available for processing, or such that one in situ temperature controller 200 may be available for processing.

[0048] Each in situ temperature controller 200 is configured to sense the voltage difference and current of the corresponding heater trace to determine a measured resistance of the heater trace. The measured resistance may be used to determine an approximate temperature of the corresponding heater zone heated by the heater trace using a correlation function. The correlation function forms a relationship between temperature and resistance based on the resistance temperature coefficient of the heater trace. In that way, once the resistance and the corresponding resistance temperature coefficient of the heater trace are known, the approximate temperature of the corresponding heater zone can be determined. For example, in situ temperature controller A (200A) is configured to measure or calculate the voltage difference of heater trace 1 by sensing the voltage at the input end of heater trace 1 and the voltage at the output end of heater trace 1 of heater zone 1 (320-A). In addition, in situ temperature controller A (200A) is configured to sense the current through heater trace 1. The current should be constant across heater trace 1 and can be measured at one or more locations, such as on line 307A. Resistance measurements can be determined from the sensed voltage difference and the sensed current, which are then used to determine the approximate temperature of the corresponding heater zone using a corresponding correlation function, as described above.

[0049] Thus, the approximate temperature of the heater zones can be determined without using temperature sensors embedded in the ESC 310. Specifically, the in situ temperature controller 200 is configured to determine the approximate temperature of the corresponding heater zones without using temperature sensors embedded in the ESC 310. The in situ temperature controller is configured to probe and / or connect to a circuit that provides current to generate heat in the heater zone of the ESC 310 including the corresponding heater trace to sense the voltage and / or current of the heater trace. The probing and / or connecting may be done in the RF high temperature environment outside the ceramic layer (e.g., by connecting to the circuit using leads). In other embodiments, the current sensing, voltage sensing, resistance measurement and / or determination, and temperature measurement and / or determination may be algorithmically programmed into the in situ temperature controller 200.

[0050] In one embodiment, the in situ temperature controllers (e.g., 200A, 200B...200N) are located inside the RF boundary 330 such that they are located within the RF hot environment of the chamber 102, such as being exposed to the process conditions of the chamber 102. In that way, embodiments of the present disclosure provide in situ resistance measurements in the RF hot environment, and further provide in situ control of the power provided to the corresponding heater traces. The in situ temperature controllers 200 may be mounted on an ESC control board configured to drive the heater zones and provide communication (e.g., via fiber optic cables to reduce RF feedback) with a user interface located outside the RF boundary (e.g., the RF cold environment). That is, the in situ temperature controllers 200 may be configured to control the power provided to the corresponding heater traces used to heat the corresponding heater zones. In one embodiment, the power is provided using pulse width modulation (PWM). The control board is configured to cause each in situ temperature controller 200 to measure the voltage and current of each heater trace in a corresponding heater zone, as described above, and to calculate the approximate temperature of the corresponding heater zone of the ESC 310.

[0051] 3B illustrates a heating system configured to provide heat to a particular heater zone of the electrostatic chuck 310 of FIG. 3A according to one embodiment of the present disclosure, where the in situ temperature controller 200 controls the temperature of the heater zone 320 as measured by a corresponding heater trace 345 configured to provide heat to the heater zone 320. Specifically, the heater trace 345 includes an input end 351 and an output end 352 coupled to the power source 240. For example, the power source 240 provides power to the input end 351 through line 305. The power source 240 is coupled to the output end 352 through line 307. The in situ temperature controller 200 is also coupled between the input end 351 and the output end 352 of the heater trace in one embodiment. For example, the in situ temperature controller 200 may be coupled to lines 305 and 307 for voltage and / or current sensing. The in situ temperature controller 200 is also coupled to the power source 240 for transmitting a control signal. For example, the heater trace 345, the in situ temperature controller 200, and the power supply 240 may be coupled in a closed loop such that the in situ temperature controller 200 is configured to control the power supplied to the heater trace 345 based on the calculated temperature of the heater zone 320 and the desired temperature of the heater zone 320.

[0052] Specifically, the in situ temperature controller 200 is configured to make in situ resistance measurements of the heater traces 345 to determine the approximate temperature of the corresponding heater zone 320 of the ESC 310. In one embodiment, the approximate temperature is determined without a temperature sensor embedded or installed in the corresponding heater zone. The disclosed embodiments provide voltage, current, and / or resistance measurements to determine the approximate temperature at high operating temperatures (e.g., above 150° C.) at a much lower cost than existing temperature sensing systems. The temperature sensing system of the disclosed embodiments also provides improved RF uniformity across the ESC footprint due to the absence of temperature sensing cutouts and bond lines in at least one layer of the ESC.

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

[0054] Additionally, the in situ temperature controller 200 is configured to perform current sensing 370 by measuring the current through the heater trace 345. For example, the in situ temperature controller 200 may be coupled to either node 356 or 355 of the input line 305 to similarly measure the current I through the heater trace 345. The in situ temperature controller 200 may also be coupled to either node 357 or 358 of the output line 307 to similarly measure the same current I through the heater trace 345. Thus, the in situ temperature controller 200 may be configured to measure and / or sense the voltage and current of the heater trace 345 to calculate an approximate temperature of the heater zone 320 of the ESC 310, as described further below. Additionally, the power controller 380 is configured to determine what power is provided to the heater trace 345 based on the determined approximate temperature of the heater zone 320, and possibly the desired temperature of the heater zone 320, as described further below. For example, the power controller 380 may provide a particular voltage level for the power supply 240 to supply to the heater trace 345, or may provide an incremental voltage to the power supply 240 to adjust the voltage in either a positive or negative direction. Heat generated by the heater trace 345 (generated by the supplied power) is transferred to a corresponding heater zone of the ESC.

[0055] 3C illustrates a power controller 380 of the in situ temperature controller 200 of FIG. 3B configured to control the power supplied to the heater trace 345 to control the temperature of the heater zone 320, according to one embodiment of the disclosure. As previously described, the in situ temperature controller 200 controls the voltage difference (V htr ) in real time and measures the current (I htr ) in real time.

[0056] Additionally, the resistance identifier 365 of the power controller 380 is configured to identify (e.g., in real time) the resistance of the heater trace 345 based on the sensed voltage difference and the sensed current. Specifically, the resistance (R htr ) can be calculated using the following equation (1): R htr =V htr / I htr (1)

[0057] The approximate temperature 395 of the corresponding heater zone 320 of the ESC 310 is determined by the identified resistance (R htr ) and a correlation function based on the resistance temperature coefficient, by the temperature correlator 385. In one embodiment, the correlation function is linear. In another embodiment, the correlation function is non-linear. In one embodiment, the approximate temperature 395 of the corresponding heater zone 320 is determined without a temperature sensor embedded or installed in the heater zone 320 of the ESC 310. As mentioned above, in one embodiment, there are no sensors provided in the ESC 310 to determine the temperature of the corresponding heater zone. Specifically, there are no temperature, voltage, and current sensors provided or embedded in the ESC 310 (e.g., in the cutout of the layer). The current and voltage sensing may be performed in the RF high temperature environment outside the ESC by the in situ temperature controller 200. For example, the voltage and current may be sensed using probes, connections, etc. Also, in one embodiment, the voltage sensing, current sensing, resistance measurement and / or determination, and temperature measurement and / or determination may be algorithmically programmed in the in situ temperature controller 200.

[0058] Specifically, the correlation function of a corresponding heater trace (e.g., trace 345) is the calibrated resistance (R htr@T0 ), and the resistance TCR of the heater trace 345 htrIn one embodiment, the calibration measurements may be determined at a calibration (defined) temperature T0 (e.g., 20° C., which is approximately room temperature). For example, the calibration may be performed at the factory during manufacturing. htr@T0 ) can be measured and / or calibrated at a known temperature T0. In general, the resistance TCR htr The temperature coefficient of resistance defines the change in resistance of a particular material per unit temperature change. That is, as the temperature of a particular material changes, the associated resistance of that material will also change as defined by its corresponding temperature coefficient of resistance. The temperature coefficient of resistance of this heater trace and / or heater trace embedded in the ESC may be known (defined) and / or calibrated as described below.

[0059] In some embodiments, the heater trace 345 includes tungsten as an electrical conductor. In other embodiments, the heater trace 345 may include one or more of molybdenum, tantalum, tungsten, palladium, ruthenium, platinum, alloys, among others, for electrical conductivity. In one embodiment, the material used for the heater trace 345 has a conductor density of about 4.1×10 -3 In another embodiment, the material used for the heater trace 345 has a minimum temperature coefficient of resistance of about 4.4×10 -3 It has a minimum temperature coefficient of resistance of (.0044).

[0060] A specific (e.g. known) temperature coefficient of resistance (TCR htr Due to the known or calibrated characteristics of the material used for the heater trace (which has zone ) can be calculated based on the following equation (2): R hrr =R htr@T0 ×[1+TCR htr ×(Temp zone -T0)] (2)

[0061] The resistance of the heater trace (R htr) are measured, and the remaining parameters (calibration resistance R htr@T0 , and temperature coefficient of resistance TCR htr ) is known as defined and / or calibrated, so the temperature of the heater trace (Temp zone ) may be determined and approximated as the corresponding heater zone temperature 395. The approximate heater zone temperature 395 may be defined as the measured temperature of the heater zone. Specifically, equation (3) begins with equation (2) and is solved for the real-time approximate heater zone temperature 395. Temp zone =(R hrr / R htr@T0 -1) / TCR htr +T0 (3)

[0062] In one embodiment, the correlation function is linear and relates the resistance of the heater trace and the temperature of the heater trace and / or the approximate temperature of the corresponding heater zone heated by the heater trace. htr is constant over the approximate temperature range, so the correlation function is linear over the temperature range (the slope of the correlation function is the temperature coefficient of resistance TCR htr In one embodiment, the TCR htr is calibrated for the heater trace material alone, where the temperature response of the heater zone is approximated to the temperature response of the heater trace used to heat the corresponding heater zone. A desirable approximation may be made between the temperature response of the heater zone and the temperature response of the heater trace when the temperature coefficient of resistance of the heater trace material is assumed to be linear.

[0063] In other embodiments, the correlation function is non-linear. htr is not constant over the approximate temperature range. htr may define the slope of the curve that defines the correlation function at a particular point. htris calibrated for the heater trace embedded in the ESC. The calibration may be performed when the correlation function is linear or nonlinear, but is particularly useful for obtaining more accurate temperature calculation results when the correlation function is nonlinear. In that case, the correlation function may be calibrated for the heater trace embedded in the ESC over an approximate temperature range. For example, measurements of the temperature of the heater zone and the resistance of the heater trace may be performed to determine a more accurate correlation function, which defines a relationship between the calibrated resistance of the heater trace and the calibrated temperature response of the heater zone heated by the heater trace.

[0064] The approximate temperature 395 of the heater zone may be provided as an input to a temperature comparator 387 of the power controller 380. A desired temperature 390 of the heater zone (e.g., predefined by a process recipe) may likewise be provided as an input to the temperature comparator 387. The temperature comparator 387 may be configured to determine a difference between the approximate temperature 395 of the heater zone and the desired temperature 390. The power sorter 391 may then be configured to analyze the difference and match the approximate temperature 395 of the heater zone to the desired temperature 390. For example, the power sorter 391 may be configured to apply a predefined response to match the two values. As such, the power sorter 391 provides as an output 399 a response to be applied in the power supply 240 to control the power supplied to the heater traces 345 of the heater zone 320. This response may be determined by a closed-loop analysis. That is, the power selector 391 of the in situ temperature controller 200 performs a closed-loop analysis of the approximate temperature 395 of the heater zone 320 to control the power supplied by the power supply 240 to the heater trace 345 so that the approximate temperature 395 matches the desired temperature 390 of the heater zone (e.g., over a predetermined period of time).

[0065] For example, the power sorter 391 may provide the voltage level (V-in) supplied by the power supply 240 as output 399 to the heater trace 345. In another embodiment, the power sorter 391 may implement an iterative process that varies the voltage level (V-in) supplied by the power supply 240 in response to a history of measured differences between the approximate heater zone temperature 395 and the desired temperature 390 in order to match the approximate heater zone temperature 395 and the desired temperature 390 over a predetermined period of time.

[0066] The logical components of the in situ temperature controller 200 and the power controller 380 in Figures 3B and 3C show example configurations for implementing their respective functions (e.g., voltage sensing, current sensing, resistance identifier, temperature correlation, temperature comparator, power screening, power control, etc.). It is understood that the functions of the logical components described in the in situ temperature controller 200 and the power controller 380 may be logically organized in a variety of different configurations. For example, some functions of the power controller 380 may be split and provided within the in situ temperature controller 200, and vice versa.

[0067] An embodiment of the present disclosure provides a multi-zone heating system for use in an electrostatic chuck. For example, each zone may be heated using a corresponding resistive element. In one embodiment, a dual-zone heating system includes a circular heating zone, such as an inner heater zone having a heater trace R-in (e.g., resistive element) for heating, and an outer zone having a heater trace R-out (e.g., resistive element) for heating. It should be recognized that the dual-zone heating system is merely an example and various layout configurations may be supported. For example, a heating system having one or more heater zones may be provided, such as a three heater zone system including an inner zone, a middle zone, and an outer zone. The number of heater zones may vary between systems, including, for example, 1 to 5 heater zones, 5 to 10 heater zones, 5 to 15 heater zones, more than 5 heater zones, more than 10 heater zones, more than 20 heater zones, more than 50 heater zones, more than 75 heater zones, more than 100 heater zones, or more than 125 heater zones. In yet other examples, the heater zones may be grouped by layer, with one set of heater zones in one horizontal layer and at least one other layer including another set of heater zones. In other embodiments, the heater zones may be in a variety of configurations, such as sectors, circularly oriented heating circles, grids of individual resistive elements, zigzag resistive elements, single resistive elements, etc. As an example embodiment, some layout configurations may provide a continuous annular resistive element for multiple zones. As previously mentioned, the resistive elements and / or heater traces used to heat the corresponding heater zones may be integrated into the ceramic that defines the pedestal that then receives the substrate for processing.

[0068] In one embodiment, a multi-zone heating system is provided in one layer of the ESC, with the zones arranged in a grid across the ESC. Each element of the grid is individually controllable to provide heat. For example, the grid may be configured as a 14×14 grid of heating elements, such as corresponding heater traces and / or resistive elements. In one embodiment, the number of heater zones may be provided in a one-to-one relationship resulting in 14×14 heater zones. In another embodiment, some heating elements are provided with redundancy such that there are fewer heater zones than there are heating elements. For example, there may be a 12×12 heater zone configuration supported by a 14×14 grid of heater elements (e.g., heater traces, resistive elements, etc.). In other embodiments, the grid pattern of heating elements may be symmetric, asymmetric, uniformly distributed, or non-uniformly distributed in grid patterns of various shapes that fit the geometry of the ESC. The described multi-zone heating system may be provided in one layer of the ESC, and may be configured to provide fine tuning of heat across the ESC.

[0069] In another embodiment, the heating system may be distributed across multiple layers of the ESC. For example, one layer may be provided for fine adjustment of the heat provided to the ESC. Fine adjustment of the heat may be provided by heating elements in a grid pattern as described above for a multi-zone heating system (e.g., a 12×12 grid of heating elements, a 14×14 grid of heating elements, etc.). The heating system may include one or more other layers of heating zones configured to provide coarse adjustment of the heat provided to the ESC. For example, one or more rings of heater zones may be provided throughout the ESC, such as a dual heater zone ESC (e.g., two heater zones), a three heater zone ESC (e.g., three heater zones), or a quad heater zone ESC (e.g., four heater zones).

[0070] In one embodiment, the disclosed embodiments are not limited by the low resolution of the temperature correlation between the heater trace and the measured temperature (e.g., by a temperature sensor) of the heater zone due to the low thermal conductivity of ceramics. In conventional temperature measurement heating systems (e.g., using direct temperature sensors), the heater trace could not be less than a threshold thickness (e.g., 10 mm) because such thicknesses could not be accurately measured with the low resolution temperature correlation. This also limited the number of heater zones that could be provided in conventional heating systems with accurate temperature sensing (e.g., using direct temperature sensors). On the other hand, the disclosed embodiments have a high resolution of the temperature correlation between the heater trace and the measured temperature of the heater zone due to the high resolution of the voltage and current measurements with low noise. In this way, the disclosed embodiments can provide heater traces with cross-sections that are significantly smaller than the previously applied 10 mm threshold. Also, the disclosed embodiments can provide heater trace cross-sectional widths (e.g., horizontal width of the cross section) of less than 10 mm and any thickness. This is due to the high resolution of the voltage and current measurements with low noise, which allows accurate measurement of the voltage and current regardless of the thickness of the heater zone, allowing a more accurate measurement of the approximate temperature of the corresponding heater zone. Additionally, embodiments of the present disclosure can provide a high degree of process control when providing heat to multiple heater zones in an ESC, since closed-loop control of the heater traces allows these heater traces to be thinned accordingly, allowing for more heater zones to be configured within the ESC (e.g., individually controlled vertical heater traces distributed throughout the ESC).

[0071] 4 is a flow diagram 400 illustrating a method for controlling a temperature of a heater zone of an electrostatic chuck using corresponding heater traces integrated with an ESC and configured to sense temperature and provide heat to the heater zone, according to one embodiment of the disclosure. The method of flow diagram 400 may be applied by one or more of the plasma processing modules 100 of FIGS. 1 and 2 and the systems described in FIGS. 3A-3C.

[0072] The method includes, at 410, providing power from a power source to a heater trace. The heater trace may be integrated into a heater zone of an ESC for a plasma processing chamber. The heater trace is configured to provide heat to the heater zone. The heater trace may have an input end and an output end coupled to a power source, as described above. The power provided to the heater trace is controlled by a temperature controller, such as a temperature controller configured to provide an in situ (e.g., in an RF high temperature environment) measurement of a resistance of the heater trace and relate the resistance to an approximate temperature of the corresponding heater zone.

[0073] The method includes sensing 420 a voltage difference between the input and output ends of the heater traces in real time. Specifically, the temperature controller is configured to sense the input voltage at the input end of the heater traces and sense the output voltage at the output end of the heater traces as described above. In that way, the voltage drop across the heater traces within the heater zone can be determined by the temperature controller. In one embodiment, the voltage and current sensing is performed in the RF high temperature environment of the plasma processing chamber.

[0074] The method includes sensing the heater trace current in real time at 430. Specifically, the temperature controller is configured to sense the current through the heater trace as described above. The current may be sensed at any of multiple nodes in the circuit since it must be equal throughout the circuit including the heater trace. For example, the current may be sensed at either the input or output end of the heater trace or at the location where a voltage is sensed. Other locations may be used to deliver the current. In one embodiment, the current sensing is performed in the RF high temperature environment of the plasma processing chamber.

[0075] The method includes identifying a resistance of the heater trace in real time based on the sensed voltage difference and the sensed current, at 440. Specifically, the temperature controller is configured to identify the resistance as described above. In one embodiment, the resistance is determined by the relationship between the voltage (V), current (I), and resistance (R) of the circuit: V=I×R.

[0076] The method includes, at 450, approximating a temperature of the heater zone based on the identified resistance of the heater trace and a correlation function. Specifically, in one embodiment, the approximate temperature of the heater zone is determined without using a temperature sensor (e.g., a temperature sensor embedded in a layer of the ESC) in the heater zone of the ESC as described above. The correlation function uses a resistance temperature coefficient of the heater trace. In an embodiment, the correlation function may be linear or nonlinear as described above.

[0077] In some embodiments, the correlation function may be linear, and the temperature coefficient of resistance is constant in an approximate range (e.g., an operating range). The correlation function is defined for a particular heater trace, and in particular for a heater trace embedded in an ESC. FIG. 5 shows an illustration of a correlation function 500, which defines a linear correlation and / or relationship between the resistance and temperature of a heater trace configured to provide heat to a heater zone of an electrostatic chuck. The correlation function 500 defines a linear correlation and / or relationship between the resistance and temperature of the heater trace, and the temperature of the .... htr ) and the slope of the correlation function is the approximate temperature coefficient of resistance (TCR) of the heater trace and / or the heater trace embedded in the ESC. htr ) In one embodiment, the correlation function 500 is calibrated to the heater trace. For example, the calibration may be performed at the factory during the fabrication and / or manufacturing of the ESC. In particular, the temperature coefficient of resistance (TCR htr ) may be known for a given material; that is, the slope of the line in the correlation function 500 is known. Calibration may be performed at a given calibration temperature (e.g., 20° C.) and calibration resistance (R htr@t0) to provide a suitable intersection point of the lines. In that way, a correlation function may be defined for a particular heater trace and / or heater traces embedded in the heater zone of the ESC.

[0078] In other embodiments, the correlation function may be non-linear. The correlation function may be calibrated for the heater trace alone or for the heater trace embedded in the ESC over a suitable operating temperature range. For example, measurements of the temperature of the heater zone and the resistance of the heater trace may be performed to determine a non-linear correlation function as described above, where the correlation function defines a relationship between a calibrated resistance of the heater trace and a calibrated temperature response of the heater zone heated by the heater trace.

[0079] In one embodiment, the closed loop analysis of the approximate temperature of the heater zone and the desired temperature of the heater zone is performed by a temperature controller. In one embodiment, the closed loop analysis is performed in situ with respect to the RF high temperature environment. As such, the power supplied to the heater traces may be controlled using the closed loop analysis as described above. For example, the temperature controller may repeatedly vary the power supplied to the heater traces to match the approximate temperature of the heater zone to the desired temperature over a period of time. In another embodiment, the temperature controller may provide a voltage input defined by a predefined response to the measured approximate temperature of the heater zone. In one embodiment, the power supplied to the heater traces is controlled by pulse width modulation (PWM). In one embodiment, in situ power control is provided to the heater traces and the closed loop analysis is performed in the RF high temperature environment of the plasma processing chamber as described above.

[0080] In another embodiment, a user interface is configured to provide information to a user. The user interface may be provided on a display device outside the plasma processing chamber. The information may be provided to the user interface, the information including a first temperature of a first heater zone of an electrostatic chuck for the plasma processing chamber configured to support a substrate. The user interface may include an alert providing a recommendation 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 (e.g., between an input end and an output end of the first heater trace) at a first heater trace integrated in the first heater zone, sense a current of the first heater trace, identify a resistance of the first heater trace based on the sensed voltage difference and current, and approximate the first temperature based on the resistance of the first heater trace and a correlation function.

[0081] In some embodiments, the alert includes a difference between a desired temperature and the temperature of the heater zone, the difference exceeding a threshold.

[0082] In another embodiment, the user interface includes a second temperature of a second heater zone of the electrostatic chuck. The second temperature is determined by a second temperature controller configured to sense a voltage difference (e.g., between an input end and an output end of the second heater trace) across a second heater trace integrated into the second heater zone, sense a current in the second heater trace, identify a resistance of the second heater trace based on the sensed voltage difference and current in the second heater trace, and approximate the second temperature based on the resistance of the second heater trace and a correlation function. In yet another embodiment, the first heater zone and the second heater zone are on different horizontal planes.

[0083] In one embodiment, 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 high temperature environment of the plasma processing chamber, and specifically, the first temperature controller performs a closed-loop analysis of the approximate first temperature to control the power supplied to the first heater trace such that the approximate first temperature corresponds to a desired temperature.

[0084] A1) In one embodiment, a plasma processing system for processing a substrate is disclosed. The plasma processing system includes a reactor with an electrostatic chuck (ESC) for supporting a substrate, the reactor configured to receive a process gas. The plasma processing system includes a heater zone of the ESC. The plasma processing system includes a heater trace integrated into the heater zone. The heater trace is configured to provide heat to the heater zone. The heater trace has an input end and an output end. The plasma processing system includes a temperature controller configured to sense a voltage difference across the heater trace and sense a current across the heater trace, identify a resistance of the heater trace based on the sensed voltage difference and the sensed current, and approximate a temperature of the heater zone based on the identified resistance of the heater trace and a correlation function. The correlation function uses a resistance temperature coefficient of the heater trace.

[0085] A2) The plasma processing system of A1, wherein the correlation function is linear or nonlinear.

[0086] A3) The plasma processing system of A1), wherein the temperature controller performs a closed-loop analysis of the approximate temperature of the heater zone to control the power supplied to the heater trace such that the approximate temperature corresponds to a desired temperature of the heater zone.

[0087] A4) The plasma processing system of A1), wherein the temperature controller is configured to provide in situ control of power supplied to the heater traces such that the temperature controller is located within the RF high temperature environment of the plasma processing chamber.

[0088] A5) The plasma processing system of A1), wherein the temperature controller approximates the temperature of the heater zone without using a temperature sensor in the heater zone.

[0089] B1) A plasma processing system for processing a substrate. The plasma processing system includes a first heater zone of an electrostatic chuck (ESC) for a plasma processing chamber, the ESC configured to support the substrate during processing. The ESC includes a first heater trace integrated into the heater zone and configured to provide heat to the first heater zone, the first heater trace having a first input end and a first output end. 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 across the first heater trace. The 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 temperature controller is configured to approximate a first temperature of the first heater zone based on the identified first resistance of the first heater trace and a first correlation function, the first correlation function using a first resistance temperature coefficient of the first heater trace.

[0090] B2) The plasma processing system of B1), wherein the first correlation function defines a linear correlation between temperature and resistance and has a slope that is approximately a temperature coefficient of resistance of the first heater trace.

[0091] B3) The plasma processing system of B1), wherein the first correlation function defines a non-linear correlation between temperature and resistance.

[0092] B4) The plasma processing system of B1), wherein the first correlation function is defined for a first heater trace integrated into a first heater zone of the ESC.

[0093] B5) The plasma processing system of B1), wherein the first temperature controller approximates the first temperature of the first heater zone without using a temperature sensor in the first heater zone.

[0094] B6) The plasma processing system of B1), wherein the first temperature controller performs a closed-loop analysis of the approximate first temperature of the first heater zone to control the power supplied to the first heater trace such that the approximate first temperature corresponds to a desired temperature of the first heater zone.

[0095] B7) The plasma processing system of B6), wherein the first temperature controller controls the power using pulse width modulation.

[0096] B8) The plasma processing system of B6), wherein the first temperature controller is configured to provide in situ control of power supplied to the first heater trace such that the first temperature controller is located within the RF high temperature environment of the plasma processing chamber.

[0097] B9) The plasma processing system of B1), comprising a second heater zone of the ESC and a second heater trace integrated into the second heater zone, the second heater trace configured to provide heat to the second heater zone and having a second input end and a second output end, the plasma processing system comprising a second temperature controller configured to sense a second voltage difference across the second heater trace to sense a second current across 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 approximate a second temperature of the second heater zone based on the identified second resistance of the second heater trace and a second correlation function, the second correlation function using a second resistance temperature coefficient of the second heater trace.

[0098] B10) The plasma processing system of B9), wherein the first heater zone and the second heater zone are on different horizontal planes.

[0099] B11) The plasma processing system of B1), wherein a horizontal width of a cross-section of the first heater trace is less than 10 mm.

[0100] FIG. 6 illustrates a control module 600 for controlling the above-described system. In an embodiment, the control module 110 of FIG. 1 and / or 200 of FIG. 2 may include some exemplary components of the control module 600. For example, the control module 600 may include a processor, a memory, and one or more interfaces. The control module 600 may be used to control the devices of the system based in part on the detected values. By way of example only, the control module 600 may control one or more of the valves 602, the filter heater 604, the pump 606, the zone heater 320, and other devices based on the detected values ​​and other control parameters. The control module 600 receives detected values ​​from a pressure gauge 610, a flow meter 612, and / or other sensors 616, by way of example only. The control module 600 may also be used to control precursor delivery and process conditions during deposition. The control module 600 will typically include one or more memory devices and one or more processors.

[0101] The control module 600 may control the operation of the precursor delivery system and deposition apparatus. The control module 600 executes a computer program that includes a set of instructions for controlling the timing of the process, the temperature of the delivery system, the pressure differential of the filter, the valve position, the mixture of gases, the chamber pressure, the chamber temperature, the substrate temperature, the RF power level, the position of the substrate chuck or pedestal, and other parameters of a particular process. The control module 600 may monitor the pressure differential and automatically switch the delivery of vapor precursor from one or more paths to one or more other paths. In some embodiments, other computer programs stored in a memory device associated with the control module 600 may be used.

[0102] The control module 600 may be configured to sense the voltage, sense the current, determine the resistance, determine the temperature of the heater zone, and control the power provided to the heater zone 320 based on the sensed voltage and current. In particular, the control module 600 may be configured to determine an approximate temperature of a corresponding heater zone of the ESC, which may be determined by a resistance measurement (e.g., determined by voltage and current sensing) of a corresponding heater trace used to heat the heater zone and a correlation function of the heater trace with the resistance temperature coefficient of the heater trace. The control module 600 may be configured to analyze the approximate temperature relative to a desired temperature and responsively determine a voltage applied to the heater trace.

[0103] Typically, there will be a user interface associated with the control module 600. The user interface may include a display device 618 (e.g., a display screen of equipment and / or process conditions and / or a graphic software screen) and a user input device 620 (pointing device, keyboard, touch screen, microphone, etc.).

[0104] Computer programs for controlling precursor delivery, deposition, and other processes in a process sequence can be written in any conventional computer-readable programming language (e.g., assembly language, C, C++, Parcal, Fortran, or others). The compiled object code or script is executed by a processor to perform the tasks identified in the program.

[0105] 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 (RF power level, low frequency RF frequency, etc.), cooling gas pressure, and chamber wall temperature.

[0106] The system software may be designed or configured in many different ways. For example, various chamber component subroutines or control objects may be written to control the operation of the chamber components necessary to perform an advanced deposition process. Examples of programs or program sections for this purpose include substrate positioning code, process gas control code, pressure control code, heater control code, and plasma control code.

[0107] The substrate positioning program may include program code for controlling chamber components used to mount the substrate on the pedestal or chuck and control the space between the substrate and other parts of the chamber (such as the gas inlet and / or target). The process gas control program may include code for controlling the composition and flow rate of gases to stabilize the pressure in the chamber and, if necessary, flowing gases into the chamber before deposition. The filter monitoring program includes code for comparing the measured difference to a preset value and / or code for switching paths. The pressure control program may include code for controlling the pressure in the chamber, for example, by adjusting a throttle valve in the exhaust system of the chamber. The heater control program may include code for controlling the current to a heating device for heating components of the precursor delivery system, the substrate, and / or other parts of the system. Alternatively, the heater control program may control the supply of a heat transfer gas, such as helium, to the substrate chuck.

[0108] Examples of sensors that may be monitored during deposition include, but are not limited to, mass flow controller modules, pressure sensors such as pressure gauge 610, thermocouples installed in the delivery system, pedestal or chuck. Appropriately programmed feedback control algorithms may be used with data from these sensors to maintain desired process conditions. The foregoing describes the implementation of embodiments of the present disclosure in single or multi-chamber semiconductor processing tools.

[0109] In some embodiments, the controller is part of a system that may be part of the examples described above. Such systems may include processing tools, chambers, processing platforms, and / or semiconductor processing equipment with specific processing components (wafer pedestals, gas flow systems, etc.). These systems may be integrated with electronics for controlling pre-, during, and post-processing operations of semiconductor wafers or substrates. These electronics may be referred to as "controllers" and may control various components or sub-components of the system. Depending on the processing requirements and / or type of system, the controller may be programmed to control any process disclosed herein, including supply of process gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow settings, fluid supply settings, position operation settings, wafer loading and unloading from tools and other transport tools, and / or wafer loading and unloading from load locks coupled or connected to the specific system.

[0110] In general, a controller may be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receive instructions, issue instructions, control operations, enable cleaning operations, enable endpoint measurements, etc. Integrated circuits may include chips in firmware format that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and / or one or more microprocessors or microcontrollers that execute program instructions (e.g., software). Program instructions may be instructions communicated to the controller in the form of various personalizations (or program files) that define operational parameters for performing a particular process on or for a semiconductor wafer or for a system. In some embodiments, the operational parameters may be part of a recipe defined by a process engineer to accomplish one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or one or more processing steps during the manufacture of a wafer die.

[0111] In some embodiments, the controller may be part of or coupled to a computer that is integrated or coupled to the system, or otherwise networked or combined with the system. For example, the controller may be in the "cloud" that allows remote access of wafer processing, or may be all or part of a fab host computer system. The computer may allow remote access to the system to monitor the progress of a manufacturing operation, review the history of past manufacturing operations, review trends or performance metrics from multiple manufacturing operations, modify parameters of a current process, set up processing steps following a current process, or initiate a new process. In some examples, a remote computer (e.g., a server) may provide process recipes to the system over a network, which may include a local network or the Internet.

[0112] The remote computer may include a user interface that allows for entry or programming of parameters and / or settings that are then communicated from the remote computer to the system. In some examples, the controller receives instructions in the form of data that specify parameters for each process step performed during one or more operations. It should be understood that the parameters may be specific to the type of process being performed and the type of tool the controller is configured to couple to or control. Thus, as described above, the controller may be distributed by including one or more separate controllers that are networked together and cooperate toward a common purpose, such as the process or control described herein. An example of a controller distributed for such a purpose would be one or more integrated circuits on the chamber that are located remotely (e.g., at the platform level or as part of the remote computer) and communicate with one or more integrated circuits that cooperate to control the process in the chamber.

[0113] Without being limited thereto, example systems may include plasma etch chambers or modules, deposition chambers or modules, spin rinse chambers or modules, metal plating chambers or modules, cleaning chambers or modules, bevel edge etch chambers or modules, physical vapor deposition (PVD) chambers or modules, chemical vapor deposition (CVD) chambers or modules, atomic layer deposition (ALD) chambers or modules, atomic layer etch (ALE) chambers or modules, ion implantation chambers or modules, track chambers or modules, and other semiconductor processing systems that may be related to or used in the fabrication and / or manufacturing of semiconductor wafers.

[0114] As described above, depending on the processing steps being performed by the tool, the controller may be in communication with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, nearby tools, tools installed throughout the factory, a main computer, another controller, or tools used to transport materials to and from tool locations and / or load ports in a semiconductor manufacturing factory.

[0115] The above description of the present embodiments is provided for purposes of illustration and description, and is not intended to be exclusive or limiting of the present disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but may be interchangeable where applicable and used in selected embodiments, even if not specifically shown or described. The same may be varied in many ways. Such variations are not considered to be departures from the present disclosure, and all such modifications are intended to be included within the scope of the present disclosure.

[0116] Although the foregoing embodiments have been described in some detail for clarity of understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims. The present embodiments are therefore to be regarded as illustrative and not restrictive, and are not to be limited to the details set forth herein, but may be modified within the scope of the claims and their equivalents. The present disclosure can also be realized in the following forms. [Form 1] A controller, a voltage sensor coupled to a heater trace integrated into the electrostatic chuck, the voltage sensor configured to sense a voltage difference across the heater trace, the heater trace being associated with a heater zone; and a current sensor coupled to the heater trace and configured to sense a current in the heater trace; a resistance identifier configured to identify a resistance of the heater trace based on the voltage difference and the sensed current; a temperature correlator configured to approximate a temperature of the heater zone based on a correlation function of the resistance and the heater trace; The correlation function uses a temperature coefficient of resistance of the heater trace. [Form 2] The controller according to aspect 1, further comprising: A controller comprising a temperature comparator configured to compare the approximated temperature to a desired temperature associated with the heater zone. [Form 3] The controller according to aspect 2, further comprising: A controller comprising: a power controller configured to adjust power to the heater trace based on a comparison of the approximated temperature to the desired temperature. [Form 4] 4. The controller according to claim 3, The power controller adjusts the power using pulse width modulation. [Form 5] 4. The controller according to claim 3, The controller is located within a RF high temperature environment of a plasma processing chamber; The controller is configured to provide in situ adjustment of the power to the heater traces. [Form 6] 4. The controller according to claim 3, The power controller performs a closed loop analysis of the approximated temperature to adjust the power to the heater traces such that the approximated temperature matches the desired temperature. [Form 7] 2. The controller according to claim 1, The temperature correlator approximates the temperature without the use of a temperature sensor. [Form 8] 1. A user interface, comprising: a display device configured to show information regarding a first heater zone of an electrostatic chuck for a plasma processing chamber; the information includes a first temperature associated with the first heater zone; The first temperature is determined by a first temperature controller, the first temperature controller comprising: sensing a voltage difference across a first heater trace associated with the first heater zone; Sensing a current in the first heater trace; identifying a resistance of the first heater trace based on the voltage difference and the sensed current; A user interface configured to approximate the first temperature based on a correlation function of the resistance and the first heater trace. [Form 9] The user interface according to aspect 8, further comprising: A user interface comprising logic configured to issue an alert based on the first temperature. [Form 10] A user interface according to aspect 9, The user interface, wherein the alert includes a recommendation providing at least one action to take based on the information. [Form 11] A user interface according to aspect 9, The alert is issued when a difference between the desired temperature of the first heater zone and the first temperature exceeds a threshold value. [Form 12] The user interface according to aspect 8, The information includes a second temperature associated with a second heater zone of the electrostatic chuck. [Form 13] 13. The user interface according to claim 12, The second temperature is determined by a second temperature controller, the second temperature controller comprising: sensing a voltage difference across a second heater trace associated with the second heater zone; Sensing a current in the second heater trace; identifying a resistance of the second heater trace based on the voltage difference across the second heater trace and the current sensed across the second heater trace; A user interface configured to approximate the second temperature of the second heater zone based on a correlation function of the resistance and the second heater trace. [Form 14] 13. The user interface according to claim 12, The user interface, wherein the first heater zone and the second heater zone are in different horizontal planes. [Form 15] The user interface according to aspect 8, The first temperature controller is further configured to compare the first temperature to a desired temperature associated with the first heater zone. A user interface. [Form 16] 16. The user interface according to claim 15, The first temperature controller is further configured to adjust power to the first heater trace based on a comparison of the first temperature to the desired temperature. [Form 17] 9. The controller according to claim 8, the first temperature controller is located within a RF high temperature environment of the plasma processing chamber; The first temperature controller is configured to provide in situ adjustment of the power to the first heater trace. [Form 18] 12. The controller according to claim 11, The first temperature controller performs a closed loop analysis of the first temperature to adjust power to the first heater trace such that the first temperature matches the desired temperature. [Form 19] 1. A method for controlling a temperature of an electrostatic chuck (ESC) in a plasma processing chamber, the ESC having a heater zone with an integrated heater trace, the heater trace having an input end and an output end, configured to provide heat to the heater zone; applying power to the heater trace; sensing a voltage difference between the input and output ends of the heater trace; sensing a current in the heater trace; identifying a resistance of the heater trace based on the sensed voltage difference and the sensed current; approximating a temperature of the heater zone based on a correlation function of the identified resistance and the heater trace without using a temperature sensor in the heater zone, the correlation function using a temperature coefficient of resistance of the heater trace; A method comprising: [Form 20] 20. The method of claim 19, further comprising: The method includes comparing the approximated temperature of the heater zone to a desired temperature associated with the heater zone. [Form 21] 21. The method of claim 20, further comprising: issuing an alert when a comparison of the approximated temperature to the desired temperature associated with the heater zone exceeds a threshold. [Form 22] 21. The method of claim 20, further comprising: displaying a comparison of the approximated temperature to the desired temperature associated with the heater zone. [Form 23] 21. The method of claim 20, further comprising: adjusting the power supplied to the heater trace based on a comparison of the approximated temperature to the desired temperature associated with the heater zone. [Form 24] 21. The method of claim 20, further comprising: The method of claim 1, wherein the power supplied to the heater trace is adjusted such that the approximated temperature corresponds to the desired temperature associated with the heater zone. [Form 25] 21. The method of claim 20, further comprising: performing a closed loop analysis of the approximated temperature of the heater zone and the desired temperature associated with the heater zone; adjusting the power supplied to the heater traces using pulse width modulation based on the closed loop analysis; A method comprising: [Form 26] 26. The method of claim 25, further comprising: providing in situ control of the power delivered to the heater traces by performing the closed loop analysis within a RF high temperature environment of the plasma processing chamber. [Form 27] 21. The method of claim 20, further comprising: The method, wherein the correlation function defines a linear correlation between temperature and resistance and has a slope that approximates the temperature coefficient of resistance of the heater trace. [Form 28] 21. The method of claim 20, further comprising: The method, wherein the correlation function defines a non-linear correlation between temperature and resistance. [Form 29] 21. The method of claim 20, further comprising: The method of claim 1, wherein the correlation function is defined for the heater trace integrated over the heater zone.

Claims

1. A controller, a voltage sensor coupled to a heater trace integrated into the electrostatic chuck, the voltage sensor configured to sense a voltage difference across the heater trace, the heater trace being associated with a heater zone; and a current sensor coupled to the heater trace and configured to sense a current in the heater trace; a resistance identifier configured to identify a resistance of the heater trace based on the voltage difference and the sensed current; a temperature correlator configured to approximate a temperature of the heater zone based on a correlation function of the resistance and the heater trace; a power controller configured to adjust power to the heater trace based on a comparison of the approximated temperature to a desired temperature associated with the heater zone; the correlation function uses a temperature coefficient of resistance of the heater trace; The controller is located within a RF high temperature environment of a plasma processing chamber; The controller is configured to provide in situ adjustment of the power to the heater traces.

2. 2. The controller of claim 1, further comprising: A controller comprising a temperature comparator configured to compare the approximated temperature to the desired temperature associated with the heater zone.

3. 2. The controller of claim 1, The power controller adjusts the power using pulse width modulation.

4. 2. The controller of claim 1, The power controller performs a closed loop analysis of the approximated temperature to adjust the power to the heater traces such that the approximated temperature matches the desired temperature.

5. 2. The controller of claim 1, The temperature correlator approximates the temperature without the use of a temperature sensor.

6. 1. A user interface, comprising: a display device configured to show information regarding a first heater zone of an electrostatic chuck for a plasma processing chamber; the information includes a first temperature associated with the first heater zone; The first temperature is determined by a first temperature controller, the first temperature controller comprising: sensing a voltage difference across a first heater trace associated with the first heater zone; Sensing a current in the first heater trace; identifying a resistance of the first heater trace based on the voltage difference and the sensed current; configured to approximate the first temperature based on a correlation function of the resistance and the first heater trace; The first temperature controller is located within the RF high temperature environment of the plasma processing chamber.

7. 7. The user interface of claim 6, further comprising: A user interface comprising logic configured to issue an alert based on the first temperature.

8. A user interface according to claim 7, comprising: The user interface, wherein the alert includes a recommendation providing at least one action to take based on the information.

9. A user interface according to claim 7, comprising: The alert is issued when a difference between the desired temperature of the first heater zone and the first temperature exceeds a threshold value.

10. A user interface according to claim 6, comprising: The information includes a second temperature associated with a second heater zone of the electrostatic chuck.

11. A user interface according to claim 10, comprising: The second temperature is determined by a second temperature controller, the second temperature controller comprising: sensing a voltage difference across a second heater trace associated with the second heater zone; Sensing a current in the second heater trace; identifying a resistance of the second heater trace based on the voltage difference across the second heater trace and the current sensed across the second heater trace; A user interface configured to approximate the second temperature of the second heater zone based on a correlation function of the resistance and the second heater trace.

12. A user interface according to claim 10, comprising: The user interface, wherein the first heater zone and the second heater zone are in different horizontal planes.

13. A user interface according to claim 6, comprising: The first temperature controller is further configured to compare the first temperature to a desired temperature associated with the first heater zone.

14. 14. A user interface as claimed in claim 13, comprising: The first temperature controller is further configured to adjust power to the first heater trace based on a comparison of the first temperature to the desired temperature.

15. A user interface according to claim 6, comprising: the first temperature controller is located within an RF high temperature environment of the plasma processing chamber; The first temperature controller is configured to provide in situ adjustment of power to the first heater trace. A user interface.

16. 10. A user interface as claimed in claim 9, comprising: The first temperature controller performs a closed loop analysis of the first temperature to adjust power to the first heater trace such that the first temperature matches the desired temperature. A user interface.

17. 1. A method for controlling a temperature of an electrostatic chuck (ESC) in a plasma processing chamber, the ESC having a heater zone with an integrated heater trace, the heater trace having an input end and an output end, configured to provide heat to the heater zone; applying power to the heater trace; sensing a voltage difference between the input and output ends of the heater trace; sensing a current in the heater trace; identifying a resistance of the heater trace based on the sensed voltage difference and the sensed current; approximating a temperature of the heater zone based on a correlation function of the identified resistance and the heater trace without using a temperature sensor in the heater zone, the correlation function using a temperature coefficient of resistance of the heater trace; performing a closed loop analysis of the approximated temperature of the heater zone and a desired temperature associated with the heater zone; adjusting the power supplied to the heater traces using pulse width modulation based on the closed loop analysis; providing in situ control of the power delivered to the heater traces by performing the closed loop analysis within a RF high temperature environment of the plasma processing chamber.

18. 18. The method of claim 17 further comprising: The method includes comparing the approximated temperature of the heater zone to the desired temperature associated with the heater zone.

19. 20. The method of claim 18 further comprising: issuing an alert when a comparison of the approximated temperature to the desired temperature associated with the heater zone exceeds a threshold.

20. 20. The method of claim 18 further comprising: displaying a comparison of the approximated temperature to the desired temperature associated with the heater zone.

21. 20. The method of claim 18 further comprising: adjusting the power supplied to the heater trace based on a comparison of the approximated temperature to the desired temperature associated with the heater zone.

22. 20. The method of claim 18 further comprising: The method of claim 1, wherein the power supplied to the heater trace is adjusted such that the approximated temperature corresponds to the desired temperature associated with the heater zone.

23. 20. The method of claim 18, The method, wherein the correlation function defines a linear correlation between temperature and resistance and has a slope that approximates the temperature coefficient of resistance of the heater trace.

24. 20. The method of claim 18, The method, wherein the correlation function defines a non-linear correlation between temperature and resistance.

25. 20. The method of claim 18, The method of claim 1, wherein the correlation function is defined for the heater trace integrated over the heater zone.

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