Multi-modal electrostatic clamping

Abstract

Multi-mode electrostatic chuck (ESC) devices, and systems and methods of operating ESCs are provided. In some embodiments, the ESC may operate in a unipolar clamping mode or a bipolar clamping mode. In some embodiments, the ESC may utilize a pair of electrodes for unipolar and bipolar clamping modes. In some embodiments, each of the pair of electrodes may be electrically coupled to a respective power source. In some embodiments, the ESC may operate in a first clamping mode (e.g., a bipolar clamping mode) and in a second clamping mode (e.g., a monopolar clamping mode) based at least on a change in the processing environment.

Description

Incorporated by Reference

[0001] The PCT application form is filed concurrently with this specification as a part of this application. Each application to which this application claims the benefit or priority as identified in the concurrently filed PCT application form is incorporated herein by reference in its entirety and for all purposes. Background Art

[0002] Semiconductor processing tools typically include one or more semiconductor processing chambers that provide an isolated environment in the semiconductor processing tool to process semiconductor wafers. Semiconductor processing tools can be used to perform plasma-based processing operations on semiconductor wafers. A plasma source is used to generate plasma, and the plasma generates neutral particles, ions and / or free radicals of the processing gas when the processing gas flows into it. Then, these particles can be made to flow to physically and / or chemically react with the substrate of interest (e.g., semiconductor wafer). In some semiconductor processing tools, multiple semiconductor wafers can be processed in a single chamber. In such a semiconductor processing tool, such a chamber may include one or more wafer processing stations, and each processing station has its own wafer support or pedestal. In some designs, the pedestal can be an electrostatic chuck (ESC), and the substrate is placed on it. The ESC or pedestal can be used to generate an electromagnetic field that can clamp the substrate to the ESC and / or bias particles to the ESC. During semiconductor manufacturing, ESCs are often used to clamp or clamp the wafer being manufactured, thereby slowing down deformation or bending during manufacturing processing.

[0003] The descriptions of background and context contained herein are provided only for the purpose of presenting the context of the disclosure as a whole. Many of the present inventions are the work of the inventors, and simply because such work is described in the background section or presented as context elsewhere in this article, it does not mean that it will be considered as prior art. Summary of the invention

[0004] In one aspect of the present disclosure, a system configured to operate an electrostatic chuck (ESC) in multiple modes is disclosed. In some embodiments, the system includes: a plurality of clamping electrodes associated with the ESC; a plurality of power sources electrically coupled to the plurality of clamping electrodes; a controller coupled to the plurality of power sources, wherein the controller is configured to: clamp a substrate on the ESC using a first clamping mode, the first clamping mode comprising a first configuration of the plurality of clamping electrodes and the plurality of power sources; and during operation of the ESC using the first clamping mode, switch from the first clamping mode to clamp the substrate on the ESC using a second clamping mode, the second clamping mode comprising a second configuration of the plurality of clamping electrodes and the plurality of power sources, the second configuration being different from the first configuration.

[0005] In another aspect of the present disclosure, a method of operating an electrostatic chuck (ESC) in multiple modes is disclosed. In some embodiments, the method includes: operating the ESC in a first clamping mode; and operating the ESC in a second clamping mode based on a change in a processing environment during a portion of the operation of the first clamping mode.

[0006] In some variations thereof, each of the first clamping mode and the second clamping mode includes clamping the substrate on the ESC using a respective configuration of clamping electrodes associated with the ESC.

[0007] In another aspect of the present disclosure, an electrostatic chuck (ESC) capable of operating in a substrate processing environment is disclosed. In some embodiments, the ESC includes: a first clamping electrode electrically coupled to a first power source; and a second clamping electrode electrically coupled to a second power source; wherein the ESC is configured to: clamp a substrate on the ESC using a first clamping mode; and switch during a portion of the first clamping mode to clamp the substrate on the ESC using a second clamping mode.

[0008] In some variations thereof, the first clamping mode includes receiving a first voltage from the first power source at the first clamping electrode and receiving a second voltage from the second power source at the second clamping electrode, the first voltage and the second voltage having opposite polarities.

[0009] In some other variations thereof, the second clamping mode includes receiving a voltage from the first power source at the first clamping electrode and receiving a voltage from the second power source at the second clamping electrode.

[0010] In another aspect of the present disclosure, a non-transitory computer readable device is disclosed. In some embodiments, the computer readable device includes a storage medium, the storage medium including a plurality of instructions, the instructions being configured to, when executed by at least one processor, cause an electrostatic chuck (ESC) to: clamp a substrate on the ESC using a first clamping mode; and switch during a portion of the first clamping mode to clamp the substrate on the ESC using a second clamping mode.

[0011] These and other features of the disclosed embodiments will be described in more detail below with reference to the associated drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Figure 1 is a block diagram illustrating a side view of a processing chamber, according to some embodiments.

[0013] Figures 2A to 2C is a diagram of an exemplary configuration of electrode pairs according to some embodiments.

[0014] Figure 3A and 3B is a block diagram illustrating an electrical coupling configuration of electrodes and a power source of an ESC, according to some embodiments.

[0015] Figure 4A and 4B is a circuit diagram depicting a configuration of a power source according to some embodiments.

[0016] Figure 4C and 4D is a circuit diagram depicting a configuration of a power source and a high voltage (HV) switch, according to some embodiments.

[0017] Figure 5A is an exemplary timing diagram showing the startup states of an ESC when using a multi-mode configuration according to some embodiments.

[0018] Figure 5B is an exemplary timing diagram showing the startup states of an ESC when using a multi-mode configuration according to some embodiments.

[0019] Figure 6 is a flow chart depicting a method of operating an ESC according to some embodiments.

[0020] Figure 7 is a flow chart depicting another method of operating an ESC according to some embodiments.

[0021] Figure 8 is a flow chart depicting another method of operating an ESC according to some embodiments. DETAILED DESCRIPTION

[0022] The present disclosure relates to electrostatic chucks (ESCs) for semiconductor processing. In semiconductor processing equipment, electrostatic chucks are often used to clamp substrates to a pedestal during plasma processing. The electrostatic chuck can be configured to generate an attractive force between the substrate and the chuck, thereby clamping the substrate. A clamping voltage can be applied to one or more electrodes in the ESC, thereby generating oppositely polarized charges between the substrate and the electrodes, respectively. In some cases, these electrodes may also be referred to as "grids". Various designs can be used to achieve clamping.

[0023] Semiconductor device manufacturing typically involves depositing a stack of multiple layers on a wafer substrate. Typically, most depositions and other processes to form devices are performed on one or more sides of the substrate. As the deposited layers accumulate, they may introduce stress into the wafer. Large net compressive stress or net tensile stress may cause the wafer to bend and deviate from the plane of the substrate (e.g., the median plane of the semiconductor wafer), which is undesirable. Such a wafer may be very sensitive to such deviations. Because features (which may reach the nanoscale) may require precise processing, the dimensions of features (e.g., traces, circuits) manufactured on the wafer may be deformed by slight positioning or bending deviations of the wafer. In addition, wafers are typically thin and susceptible to internal stress or tensile / compressive stress, especially during the manufacturing process (deposition, etching, heating, layering, etc.).

[0024] In addition, certain processing steps (e.g., photolithography) are very precise, and if the wafer is not substantially flat, these processing steps may produce undesirable results. This problem may manifest as defocusing of the photolithography. An exemplary stack that may cause these problems is a stack with alternating layers of oxide and nitride (e.g., silicon oxide, silicon nitride, silicon oxide, silicon nitride). Another exemplary stack that may cause bending includes alternating layers of oxide and polysilicon (e.g., silicon oxide, polysilicon, silicon oxide, polysilicon). Other examples of stack materials that may be problematic include, but are not limited to, tungsten and titanium nitride. The materials in these stacks can be deposited via chemical vapor deposition techniques such as plasma enhanced chemical vapor deposition (PECVD), low pressure chemical vapor deposition (LPCVD), metal organic chemical vapor deposition (MOCVD), atomic layer deposition (ALD), plasma enhanced atomic layer deposition (PEALD), or via direct metal deposition (DMD) and other methods. These examples are not intended to be limiting.

[0025] Various techniques have been designed to combat the bow problem. Many such techniques involve adjusting the deposition process to reduce or counteract internal stresses in the deposited layer. One such technique is electrostatic clamping, which can be performed in a manner such that the bow is reduced or eliminated (e.g., the clamped wafer exhibits a bow of less than about 150 μm). A device known as an electrostatic chuck (ESC) may be practical for combating the bow. The clamping action of using an ESC to hold the substrate or wafer in place results in consistent and accurate feature fabrication.

[0026] There are many variations and configurations of ESCs. In a monopolar ESC with a single clamping electrode, the single electrode can have a voltage applied to it, and an opposite charge can be induced in the substrate using, for example, a plasma generated above the substrate. Thus, a clamping force can be applied to oppose the plasma induced bias on the substrate.

[0027] In a bipolar ESC, the electrostatic chuck has a pair of complementary and coplanar clamping electrodes that can be embedded in a base structure. The electrodes can be connected to terminals of a power source (or in some embodiments, multiple power sources), or to another system configured to apply a potential to the electrodes. Here, a force may be applied between a pair of complementary electrodes, one positive and one negative, with respect to the substrate. These electrodes can be positioned so that they are located below the wafer on the substrate. The opposite charges can interact with the substrate, particularly with the bottom surface of the substrate, thereby pulling the substrate toward the electrostatic chuck and clamping the substrate to the chuck. In some embodiments, one or more of these clamping electrodes can be "D-shaped". However, various other electrode shapes can still be used, including Figures 2A to 2C Cross clamped electrodes or concentric clamped electrodes as shown.

[0028] In some cases, an ESC may include more than two electrodes. For example, in a tripolar or multipolar ESC, a voltage may be applied between a plurality of electrodes (e.g., three or more) to maintain a time-averaged substrate bias voltage at zero in a particular region of the substrate, or to control it to a set point, such as a desired or target bias voltage value.

[0029] Unipolar clamping requires the presence of a plasma (e.g., in a processing chamber used with an ESC) before the substrate (e.g., wafer) can be clamped. In some cases, this can result in a high bow wafer not being clamped or not being fully clamped because the plasma discharges from the surface before the wafer can be flattened. Additionally, the bow can be reintroduced (to an otherwise flat wafer) when the plasma intensity is reduced or turned off.

[0030] Bipolar clamping can be performed in the presence or absence of plasma, which eliminates the de-clamping risk associated with monopolar clamping and may also be less sensitive to wafer top films. However, for certain film and wafer types (e.g., carbon deposition processes and certain ALD applications), bipolar clamping may cause the target deposition process to have azimuthal non-uniformities related to relative polarity, resulting in a "potato chip" surface. In addition, bipolar clamping may, in some cases, cause preferential damage to chamber components or cause parasitic effects (gases excited into undesired plasma) that may affect the repeatability of the process. Tripolar or multipolar alternating current (AC) clamping can address the above risks associated with bipolar clamping. However, multipolar configurations involve more electrodes (e.g., three or more), higher power and / or more expensive components (e.g., power supplies), and tighter thermal operating restrictions for susceptors operating in the Johnsen-Rahbek (JR) region.

[0031] Therefore, it may be desirable to configure an electrostatic chuck, depending on the application and processing conditions (eg, presence of plasma), to take advantage of the respective advantages of the aforementioned monopolar and bipolar clamping.

[0032] The following terms are used throughout this specification:

[0033] As used herein, "electrostatic chuck" (ESC) refers to a chuck that uses electrostatic force to clamp a wafer to the chuck during processing. An ESC can use one or more electrodes. A voltage can be applied to the one or more electrodes. The applied voltage can cause a current to flow, thereby causing charge migration through a dielectric layer between the chuck and the wafer or substrate being processed. Therefore, the opposite charge accumulated at the electrode relative to the wafer can cause the wafer to be clamped or clamped on the chuck by electrostatic force. In some cases, these electrodes can be integrated in the ESC, or can be separated from the ESC. In some embodiments, an ESC can refer to an electrode that generates an electrostatic force.

[0034] In some embodiments, the ESC can use plasma in the circuit. In some embodiments, the ESC can use multiple electrodes that simultaneously apply potentials of different polarities to the substrate. Specifically, in some embodiments, the ESC can be a bipolar as described above. In some embodiments, the ESC can be a monopolar as described above. In some embodiments, the ESC can be a tripolar or multipolar (having three or more electrodes).

[0035] As used herein, "platform" refers to the top surface of the ESC on which the wafer being manufactured is placed. There may be a gap between the wafer and the platform surface (eg, upper surface), generally referred to herein as "d".

[0036] As used herein, "base" may refer to a structure or housing that supports or includes the platform.

[0037] The terms "semiconductor wafer," "wafer," "substrate," "wafer substrate," and "partially fabricated integrated circuit" may be used interchangeably. It will be understood by one of ordinary skill in the art to which the present invention pertains that the term "partially fabricated integrated circuit" may refer to a semiconductor wafer during any of a number of stages of integrated circuit fabrication being performed thereon. Wafers or substrates used in the semiconductor device industry typically have a diameter of 200 mm, 300 mm, or 450 mm. In addition to semiconductor wafers, other workpieces that may utilize the disclosed embodiments include various articles of manufacture, such as printed circuit boards, magnetic recording media, magnetic recording sensors, mirrors, optical elements, display devices or components (such as backplanes for pixelated display devices), flat panel displays, micromechanical devices, and the like. The workpiece may be of various shapes, sizes, and materials.

[0038] As used herein, "semiconductor device manufacturing operations" are operations performed during the manufacture of semiconductor devices. As mentioned herein, such manufacturing operations are sometimes referred to as "processing" or "machining". Examples of processing include depositing materials on a substrate, selectively etching materials from a substrate, and ashing of photoresists on a substrate. Typically, the entire manufacturing process includes multiple semiconductor device manufacturing operations, each of which is performed in its own semiconductor manufacturing tool (e.g., a plasma reactor, an electroplating tank, a chemical mechanical planarization tool, a wet etching tool, etc.). Categories of semiconductor device manufacturing operations include subtractive processing, such as etching processing and planarization processing, and additive processing, such as deposition processing (e.g., physical vapor deposition, chemical vapor deposition, atomic layer deposition, electrochemical deposition, electroless deposition). In the context of etching processing, substrate etching processing includes the processing of etching a mask layer, or more broadly, the processing of etching any material layer previously deposited and / or otherwise residing on the substrate surface. Such etching processing can etch a stack of multiple layers in a substrate.

[0039] "Fabrication equipment" refers to equipment in which manufacturing processes are performed. Fabrication equipment typically has a processing chamber in which a workpiece resides during processing. Typically, when in use, the fabrication equipment performs one or more semiconductor device fabrication operations. Examples of fabrication equipment for semiconductor device fabrication include deposition reactors, such as plating tanks, physical vapor deposition reactors, chemical vapor deposition reactors, and atomic layer deposition reactors, and subtractive processing reactors, such as dry etch reactors (e.g., chemical and / or physical etch reactors), wet etch reactors, and ashers.

[0040] When referred to herein, the manufacturing equipment is sometimes referred to simply as a "processing chamber". In various embodiments, the processing chamber is generally a sealed enclosure in which the substrate is fixed during processing. The processing chamber may include components related to the delivery and removal of gases. It may also include components related to the generation of plasma in the chamber and the control of the properties of the plasma. It may include components for controlling pressure, including evacuating the chamber. In the context of the present disclosure, the processing chamber may include a pedestal on which the substrate is located when processing. The pedestal may be equipped with a chuck such as an ESC to hold the wafer in place during processing.

[0041] As used herein, "wafer bow" may refer to deformation of a wafer. Wafer bow may occur during manufacturing, such as due to stress during deposition of material on the active surface of a wafer substrate. Wafer bow may occur during various types of manufacturing, such as when depositing large material stacks. Wafer bow may cause complications in subsequent processing steps. For example, if the amount of bow is too large, the wafer may not be properly clamped. In addition, if certain processing steps (e.g., photolithography) are performed on an excessively bowed wafer, undesirable results may occur.

[0042] Wafer bow can be measured as the deviation of the average or median distance of the surface of the wafer from a reference plane. The median surface point of the wafer can be the center point of the wafer (e.g., in the case of concave bow or dome bow) or an edge point and / or the average edge point of the wafer (e.g., in the case of warp or convex bow).

[0043] As used herein, "wafer unclamping" refers to a state in which a wafer is no longer clamped to a platform of an electrostatic chuck (ESC). As used herein, when wafer bending is detected during the manufacture or processing of a wafer, or when wafer bending exceeding a threshold amount is detected, then the wafer may be considered unclamped from the ESC. It should be noted that, as used herein, wafer bending may be associated with a numerical value representing the degree of bending. In contrast, wafer unclamping may be a binary classification representing whether a wafer is clamped to a platform.

[0044] As used herein, "power source" may refer to a device or system that provides power to another device or system part. In some embodiments, the power source may provide direct current (DC) and / or radio frequency (RF) power to one or more electrodes. In some embodiments, alternating current (AC) may be received at the power source and converted to DC. In some implementations, the desired voltage provided by the power source may be selected. In some cases, the system may include or be associated with multiple power sources. In some implementations, a first power source may be associated with an electrode (e.g., configured to provide power thereto), and a second power source separated from the first power source may be associated with a second electrode (e.g., configured to provide power thereto). In some embodiments, the power source may be electrically coupled to at least one controller, the controller being configured to determine the operating parameters used by the power source and / or the electrode powered by the power source, and providing a signal to the power source so that the power source provides power according to the operating parameters. Examples of such operating parameters include voltage, power, and current provided by the power source.

[0045] In some embodiments, the power source may include or be associated with an internal switch or an external switch that can switch the current flow from one or more power sources. The switch can be used to switch between at least one power source and at least one other power source. In some cases, the switch can switch the electrical path between a power source and multiple power sources. A power supply or a power supply unit (PSU) can be an example of such a power source. The power supply can be rated by the wattage that will provide the power suitable for use in the system (e.g., providing the required power to one or more electrodes). Electrostatic chuck operation mode

[0046] Figure 1 1 is a block diagram according to some embodiments, which depicts a side view of a processing chamber 100. The processing chamber 100 can be used with systems or components used for various plasma processing techniques, such as plasma enhanced chemical vapor deposition (PECVD), plasma etching, plasma stripping or ashing, sputtering, plasma spraying, etc. The processing chamber 100 may include an electrostatic chuck (ESC) 102 configured to support a substrate 120 (e.g., a wafer). The ESC may also be referred to as a "pedestal" herein. In some embodiments, the ESC 102 may include a collection of electrodes 118, wherein the electrodes 118 may include clamping electrodes 106 and 107, and a blocking electrode 108. The blocking electrode 108 and the clamping electrodes 106, 107 may have one or more electrical leads 116 configured to electrically connect the electrodes directly or indirectly to at least one RF power source 132, wherein the RF power source may provide direct current (DC) and / or radio frequency (RF) power to the electrodes.

[0047] In some implementations, the clamping electrodes 106, 107 and / or the blocking electrode 108 can be thin sheets of conductive material (e.g., metal) that are machined to have the shapes described herein. In some implementations, the electrodes can have multiple parts. In some implementations, the electrodes can have slots or holes that allow particles to move through them or be made of a mesh; this can reduce the risk of post-sintering debonding because the ceramic particles can be sintered through the electrodes, not just around them. In some implementations, the electrodes can be a metal mesh, such as a woven mesh with multiple overlapping and electrically connected metal strands. Regardless of the specific details of the electrode material, the electrodes can be machined into the shapes discussed herein.

[0048] As described elsewhere above, a bipolar electrostatic chuck (as compared to a monopolar electrostatic chuck) includes two clamping electrodes, e.g. Figure 1 The clamping electrodes 106 and 107 shown in FIG. The clamping electrodes 106 and 107 may have opposite voltages (eg, −500 V and +500 V) so that the substrate 120 is pulled toward the ESC 102 , thereby clamping the substrate on the ESC 102 .

[0049] However, it should be noted that the two clamping electrodes 106 and 107 do not necessarily have to have opposite voltages, but can have the same voltage. Advantageously, this configuration, in which the two electrodes can receive the same or opposite voltages, allows the ESC to operate in both unipolar and bipolar modes, as will be discussed in more detail below.

[0050] Back to Figure 1 In general, the blocking electrode 108 (also referred to as an "outer electrode," "edge electrode," or "averaging electrode") can improve the uniformity of processing operations performed on the substrate. In some embodiments, the blocking electrode 108 can also extend around the clamping electrodes 106 and 107. In some embodiments, the blocking electrode 108 can have an annular shape, or an annular portion associated with the blocking electrode 108. In some embodiments, the annular portion can surround the clamping electrodes 106 and 107 when viewed from above. The blocking electrode can average outliers associated with the positive and negative polarities of the clamping electrodes, thereby smoothing the interaction of the clamping electrodes with the wafer. During wafer processing operations, the blocking electrode can also interact with the plasma above the wafer to improve the uniformity of the processing. More specifically, the RF power provided to the blocking electrode 108 can control the region where the plasma is formed, particularly the radius of the plasma. Because plasma processing may have center-to-edge non-uniformity due to the plasma, the RF power provided to the barrier electrode 108 and the clamping electrodes 106, 107 may be adjusted to control the plasma and improve uniformity.

[0051] In some embodiments, the ESC 102 can be configured to support a substrate 120, which can be provided in a substrate processing environment, such as the processing chamber 100. The substrate 120 (which may also be referred to as a substrate or semiconductor substrate) can be a silicon-based or other semiconductor wafer, such as a 200 mm wafer, a 300 mm wafer, or a 450 mm wafer, including a wafer having one or more layers of material (e.g., a dielectric material, a conductive material, or a semiconductor material) deposited thereon. It should be understood that the processing chamber 100 and ESC 102 described herein can be designed for 300 mm wafers in one embodiment. Appropriate modifications can be made to scale various components for use with larger or smaller wafers (e.g., the electrodes can be scaled according to the diameter of the wafer to be processed).

[0052] In some embodiments, a ring 114 (e.g., an edge ring or a repelling ring) can also be placed on the ESC 102. In some implementations, the ring 114 can be a ceramic ring that is placed to protect the pedestal / ESC in the processing chamber from damage caused by the plasma, and / or the ring 114 can assist in controlling the plasma. In some implementations, the ring 114 can be a replaceable component.

[0053] In some embodiments, the showerhead 104 can be positioned above the ESC 102. During processing operations, a process gas can flow through the showerhead 104 toward the substrate 120. In some embodiments, during operation, a plasma 110 can be formed above the substrate 120. In some embodiments, the showerhead 104 can include or be otherwise coupled to a plasma generation system (not shown) that can be used to generate the plasma. The showerhead 104 (or plasma generator system) and the ESC 102 (including the clamping electrode and the blocking electrode) can be electrically coupled to the RF power supply 132 and the matching network 130 to power the plasma. During operation, the RF power supply 132 and the matching network 130 can be operated at any suitable power to form a plasma having a desired composition of matter. The plasma 110 can have a plasma edge region 112 located near the outer edge of the substrate 120.

[0054] In some embodiments, the controller 111 can be operably coupled to the RF power source 132 to control its operation. The controller 111 can be an analog controller, a discrete logic controller, a programmable array controller (PAL), a programmable logic controller (PLC), a microprocessor, a computer, or any other device capable of performing operations to implement processing operations. In some exemplary embodiments, the controller 111 can be configured to determine the amount of power to be supplied to the showerhead, the clamping electrode, and the blocking electrode, and to provide commands to the RF power source 132. In addition to controlling the RF power source 132, the controller 111 can also be operably coupled to the gas distribution system 177 and can be configured to provide commands thereto to supply a specified amount of processing gas to the wafer.

[0055] In some embodiments, the gas distribution system 177 can be coupled to one or more gas sources and include one or more corresponding valves or other flow control components (e.g., mass flow controllers and / or liquid flow controllers). In some embodiments, the controller 111 can be connected to one or more valves or other flow control components to switch states to allow different gases or gas combinations to flow at different times and / or flow rates. In some embodiments, the one or more gas sources can be fluidly connected to a mixing vessel to allow mixing and / or conditioning of the process gases before they flow over the wafer.

[0056] In some embodiments, the RF power source 132 may be a radio frequency (RF) energy source or other energy source that can supply power to the electrode and excite the electrode to form an electric field. In some exemplary embodiments, the RF power source 132 may include an RF generator (not shown) that is configured to operate at a desired frequency. For example, the RF generator may be configured to operate in a frequency range of 0.2 MHz to 20.0 MHz. In some exemplary embodiments, the RF generator may operate at 13.56 MHz. In some exemplary embodiments, the RF power source 132 may include a matching network 130 that is located between the RF generator and one or more elements described herein (e.g., a plasma generator system or ESC 102). The matching network 130 may be an impedance matching network that is configured to match the impedance of the RF generator to the impedance of the electrode connected to the RF generator. In this regard, the matching network 130 may be composed of a set of components, such as a phase angle detector and a control motor; however, in other embodiments, it should be understood that the matching network may also include other or additional components.

[0057] As described above, wafers may have non-uniformities from processing operations. Various designs of ESC 102, particularly various designs and patterns (e.g., bipolar, monopolar) of clamping and / or blocking electrodes, may reduce such non-uniformities, particularly non-uniformities corresponding to the clamping and / or blocking electrodes.

[0058] In some embodiments, the ESC, including the ESC 102, can be manufactured by a sintering process. The clamping electrodes 106, 107 and the blocking electrode 108, as well as other elements in the base / ESC 102 and the electrical connector, such as metal wires, can be provided in a powder, which can be heated and / or compressed to sinter the powder together to form a base in which the above-mentioned components are embedded. The powder can be a ceramic, such as aluminum oxide or aluminum oxide nitride, which forms a single component during sintering. In some embodiments, the powder may be in an "unfired" state, which can be easily machined. The ESC can be constructed by stacking the components and powder together, and then firing the entire ESC to sinter the ceramic powder. Since the sintering process can cause the expansion and contraction of various components in the base to cause movement of these components (and potential defects caused by such movement), the manufacturing can be simplified by aligning the components in fewer planes. Therefore, the clamping electrodes 106, 107 and the blocking electrode 108 can be coplanar to reduce manufacturing costs. Furthermore, connections to these components, such as electrical connections to the clamping electrodes 106, 107 and the barrier electrode 108, may be arranged along the vertical center axis to reduce manufacturing complexity.

[0059] Figures 2A to 2C is a diagram of example configurations of electrode pairs according to some embodiments. Figure 2A A perspective view of a pair of "D-shaped" electrodes is depicted. In some embodiments, the pair of electrodes includes a coplanar first electrode 202 and a second electrode 204. The first electrode 202 and the second electrode 204 may be Figure 1 An example of clamping electrodes 106 and 107 is shown in FIG. Figure 2B A top view of a pair of concentric electrodes is depicted. In some embodiments, the concentric electrodes include a first electrode 206 and a second electrode 208. The first electrode 206 can surround the second electrode 208. Figure 2C A top view of a pair of interdigitated electrodes is depicted. In some embodiments, the interdigitated electrodes include a first electrode 210 and a second electrode 212 that have shapes that allow them to be configured in an interlocking or interdigitated manner with each other without physically contacting each other.

[0060] In some implementations, electrode pairs, such as the first electrode and the second electrode, can be operated in a monopolar mode, wherein the two electrodes have the same voltage and polarity. In some implementations, the first electrode and the second electrode can be operated in a bipolar mode, wherein the polarity of one electrode is opposite to the other electrode (e.g., -500V and +500V). In some implementations, these electrode pairs can be electrically connected to corresponding power sources respectively. More specifically, the first electrode can be powered by a first power source, and the second electrode can be powered by a second power source.

[0061] In some implementations, the electrode pairs can be electrically coupled to a power source. That is, the first electrode and the second electrode can be electrically connected to a single power source, and the single power source can power the electrodes in a monopolar configuration at certain times and in a bipolar configuration at other times. However, in some implementations, multiple power sources can power the electrodes in a monopolar configuration at certain times and in a bipolar configuration at other times, as described above.

[0062] Figure 3A and 3B is a block diagram illustrating an electrical coupling configuration of electrodes and a power source of an ESC, according to some embodiments.

[0063] In some embodiments, at least one controller 302 can communicate with multiple power sources 304, 306. Such a controller can be configured to determine operating parameters of the power source and / or the electrode powered by the power source, and provide a signal representing the operating parameter to the power source so that the power source generates and provides power according to the operating parameter. Examples of operating parameters include voltage, power, and current provided by the power source. In some embodiments, at least one first power source and a separate second power source can be coupled to respective clamping electrodes. For example, the first clamping electrode 308 (e.g., Figure 1 The clamping electrode 106 shown in FIG. 1 can be coupled to the first power source 304, and the second clamping electrode 310 (e.g., clamping electrode 107) can be coupled to the second power source 306. In some embodiments, these power sources can be connected in parallel, such as Figure 3A shown.

[0064] In some embodiments, these power sources can be connected in series, such as Figure 3B As shown, the clamping electrodes 308, 310 are both coupled to a first power source 314, which is in turn connected in series with a second power source 316. At least one controller 312 can communicate with the power sources 314, 316.

[0065] In some embodiments, at least one controller can be configured to provide operating parameters to at least the first and second power sources so that the respective associated clamping electrodes can operate in (i) a bipolar mode in which the potentials of the first and second clamping electrodes are opposite and / or (ii) a monopolar mode in which the first and second clamping electrodes have the same potential. In the bipolar mode, the first power source can provide a voltage of -500 V to the first clamping electrode, and the second power source can provide a voltage of +500 V to the second clamping electrode. In the monopolar mode, both the first and second power sources can provide the same voltage (e.g., +500 V).

[0066] In some embodiments, to minimize stress on components that may cause switching (e.g., circuits, clamping electrodes), soft start circuitry may be used in the power source. Such circuitry may include active and passive devices that help to reduce the voltage before raising it to the reversal value. In some embodiments, overload protection such as a circuit breaker, fuse (e.g., thermistor, thermal fuse), or current limiting circuit may also be used.

[0067] In some embodiments, at least a third power source may be coupled to at least one of the clamping electrodes.Variations of the above-described parallel and series configurations, as well as the three-source configuration, are discussed in more detail below.

[0068] Advantageously, powering multiple electrodes with different power sources avoids the use of mechanical switches, since switching between high voltages may require the use of a damper, which is a circuit used to dampen voltage spikes caused when a switch is opened. In addition, the sudden change in polarity or potential caused by switching between modes may cause arcing with any existing plasma in the process chamber. In addition, a controller coupled to these power sources can determine the precise voltage levels to transition between bipolar and unipolar modes, including responding to process chamber conditions (e.g., undesired plasma extinguishing) to prevent sudden discharges. Therefore, the process chamber can be stabilized by using different power sources.

[0069] As described above, the controller can be configured to instruct the first and second power sources to provide appropriate voltages via the above operating parameters. In some embodiments, to prevent an imbalance in the average bias voltage between the electrodes, both power sources can be set to 0V to close the clamp while the plasma is present to prevent any arcing and facilitate de-chucking of the wafer.

[0070] However, some implementations may use a power source topology in which a single power source is configured to generate the appropriate voltage in either bipolar mode (providing opposite voltages to respective clamping electrodes) or unipolar mode (having only a single clamping electrode). Such a single power source may be a transformer, for example, configured to supply half the total voltage through two "legs" separated by a center tap (e.g., Figures 4B to 4D In some embodiments, a DC step-up (boost) controller or regulator may be used to generate the differential voltage.

[0071] In some embodiments, a field effect transistor (FET) can be used to switch a signal between two (or more) clamping electrodes or two (or more) power sources. In some implementations, a metal oxide semiconductor field effect transistor (MOSFET) can be used. A FET is typically a three-terminal circuit with a gate (G) terminal, a source (S) terminal, and a drain (D) terminal. Because it has a very high input (gate) resistance, a FET can act as a switch, with the voltage between the gate and the switch (V GS ) is appropriately positive, for example, above the threshold voltage (V GS >V TH ) is on (drain current flows), while at V GS =0 or V GS <V TH Such a FET can enable a controller or circuit to switch high current or high voltage loads. In some implementations, multiple FETs can be arranged in parallel. The FET can be a depletion-mode FET, which conducts current between the drain-source terminals in the absence of a gate voltage. In some embodiments, the MOSFET can be an enhancement-mode MOSFET (conducts current between the source-drain region only when a voltage is applied to the gate terminal) or a depletion-mode MOSFET.

[0072] Figures 4A to 4D is a circuit diagram according to some embodiments disclosed herein, which depicts different power source configurations for clamping electrodes. Each of these configurations is coupled to multiple (e.g., two) electrodes via power source terminals identified as V_D1 and V_D2. For example, a first clamping electrode can be coupled to at least power source terminal V_D1, and a second clamping electrode can be coupled to at least power source terminal V_D2.

[0073] Figure 4AA configuration of a first unipolar power source 402 and a second unipolar power source 404 coupled to the first unipolar power source 402 is shown, wherein each power source is configured to provide a maximum DC voltage. Each power source is a voltage source and may be referred to as a voltage source. The first unipolar power source 402 and the second unipolar power source 404 may be coupled to a controller (e.g., Figure 3A As shown), the controller is configured to cause one or more of the first unipolar power source 402 or the second unipolar power source 404 to increase or decrease the voltage. Figure 4A In one exemplary configuration, the first unipolar power source 402 can be boosted to -2000V (at V_D1) of the clamping electrode when plasma is present in the process chamber to implement a unipolar clamping mode. In another exemplary configuration, the first unipolar power source 402 can be boosted to -1000V, while the second power source 404 can be boosted to +1000V to implement a bipolar clamping mode using multiple (e.g., two) clamping electrodes (at V_D1 and V_D2).

[0074] Figure 4B 1 shows a configuration of a unipolar power source 412 and a bipolar power source 416 coupled in series with the unipolar power source 412. The bipolar power source 416 may include a plurality (e.g., two) of voltage sources 414a, 414b connected in parallel with each other. The unipolar power source 412 and the bipolar power source 416 may be coupled to a controller (e.g., Figure 3B ), which is configured to cause one or more of the unipolar power source 412 or the bipolar power source 416 to step up or down in voltage. Figure 4B In one example configuration, the unipolar power source 412 can be boosted to -1000V, and the voltage sources 414a, 414b can be supplied with voltage by the unipolar power source 412, so that the two electrodes (at V_D1 and V_D2) provide the same voltage to the clamped substrate, thereby achieving unipolar clamping. In another example configuration, the voltage sources 414a, 414b can provide +1000V and -1000V to the electrodes at V_D1 and V_D2, respectively, to achieve a bipolar clamping mode.

[0075] Figure 4C A configuration of a bipolar power source 426 coupled to a plurality (e.g., two) high voltage (HV) switches 428a, 428b is shown. In some embodiments, the HV switches may include FETs as described above. Figure 4C In an exemplary configuration, switches 428a, 428b may be provided with a small threshold voltage, or no voltage (V GS ), thereby allowing or not allowing voltage to flow to one or more clamping electrodes via V_D1, V_D2, or both.

[0076] Figure 4D A bipolar power source 436 and a unipolar power source 434 are shown connected to each of a plurality (e.g., four) HV switches 438a, 438b, 438c, 438d, which may supply power to one or more clamping electrodes depending on the switch state. In some embodiments, these HV switches may include FETs. In some cases, such as Figure 4D The additional power sources in the configuration can achieve multiple stages of voltage rise or fall, which can reduce stress on the components. For example, in the bipolar clamping mode, V_D1 and V_D2 can receive +500V and -500V from the bipolar power source 436. In order to switch from the bipolar clamping mode to the unipolar clamping mode, the unipolar power source 434 can be enabled and the bipolar power source 436 can be disabled by closing switches 438a and 438b and opening switches 438c and 438d. Therefore, the voltage can be reduced for these clamping electrode portions that are each at -250V. Thereafter, either switch 438c or 438d can be closed to provide power to only one clamping electrode at -500V.

[0077] In some embodiments, the aforementioned soft start circuit or overload protection circuit may be used in conjunction with the above configuration to minimize stress or overload that may be caused to components by switching, voltage rise or fall.

[0078] Figure 5A 5 is an exemplary timing diagram 500 showing the startup states of an ESC when using a multi-mode configuration according to some embodiments. In some implementations, the ESC can be in a bipolar clamping mode 502 to utilize multiple clamping electrodes (e.g., clamping electrodes 106 and 107) with opposite polarities, or in a monopolar clamping mode 504 to utilize multiple clamping electrodes with the same polarity. In some implementations, the ESC can switch between the bipolar clamping mode 502 and the monopolar clamping mode 504, and vice versa, as previously described.

[0079] The exemplary timing diagram 500 indicates that the bipolar clamping mode 502 is initially enabled, while the monopolar clamping mode 504 is initially not enabled. 0 ), plasma power may be applied (e.g., by a plasma generation system) to form a plasma (e.g., within a processing chamber where the ESC is located). 0 Before this, there is no plasma in the process chamber. 0 and t 1 In some cases, initially operating the ESC in bipolar clamping mode 502 before the plasma ignites can reduce the risk of discharge to the substrate surface.

[0080] In some embodiments, when plasma is present in the substrate processing environment (e.g., processing chamber 100), the ESC can be 1 504. While bipolar clamping can be performed with or without the presence of a plasma, monopolar clamping involves interaction with the plasma; thus, the monopolar clamping mode 504 can be switched from the bipolar clamping mode to the monopolar clamping mode at some point in time after the plasma is ignited (e.g., at t 0 After or at t 1 In some cases, t 1 Can be immediately followed by t 0 After that. In some cases, t 1 Can be in t 0 The process is performed within a predetermined time (e.g., several milliseconds or seconds) thereafter. 1 At t, the bipolar clamping mode 502 may end and the monopolar clamping mode 504 may begin. Switching from the bipolar clamping mode to the monopolar clamping mode may include changing the voltage and polarity of one of the clamping electrodes to match the other clamping electrode, such as changing from -500V to +500V so that the two electrodes become the same polarity. In some implementations, the voltage may be gradually transitioned rather than changed immediately, resulting in the bipolar clamping mode 502 at t 1 At some time later (e.g., at t 2 The monopolar clamping mode 504 can continue while the plasma power is applied, or can be switched to the bipolar clamping mode 502 (e.g., when the plasma power is applied). Figure 5B The 4 and t 5 Please note that Figure 5A Relative time values ​​are not to scale, and may represent arbitrary relative time positions.

[0081] Figure 5B 500 is an exemplary timing diagram 520 showing the startup state of the ESC when a multi-mode configuration is used according to some embodiments. In some embodiments, the ESC may initially be in a monopolar clamping mode 504. In some cases, the monopolar clamping mode 504 may have been initiated according to the exemplary timing diagram 500. In some cases, the monopolar clamping mode 504 may be turned on near the startup point. In both cases, the plasma has been ignited in the processing chamber and the substrate has been exposed to the plasma, allowing the use of the monopolar clamping mode 504. Monopolar clamping can beneficially reduce discharge problems and parasitic plasma associated with bipolar clamping.

[0082] In some embodiments, the ESC can be switched from the monopolar clamping mode 504 to the bipolar clamping mode 502. For example, in the case where the plasma has not been extinguished (eg, plasma power is still being applied), the ESC can be switched from the monopolar clamping mode 504 to the bipolar clamping mode 502.3 The bipolar clamping mode is started 502. Slightly at t 3 After that, for example, at t 4 When t is reached, the plasma power may be interrupted and the monopolar clamping mode 504 may be stopped. In some cases, even though the plasma power has been interrupted, the plasma may still be present in the processing chamber. Therefore, in some implementations, the monopolar clamping mode 504 may be stopped at t 4 At some time later (e.g., at t 5 The bipolar clamping mode 502 may be stopped when no plasma power is applied or when it is switched to the monopolar clamping mode 504 (e.g., at t 0 and t 1 Please note that the reference to Figure 5B Relative time values ​​are not to scale, and may represent arbitrary relative time positions.

[0083] In some implementations, switching to the bipolar clamping mode 502 can correspond to a timing associated with plasma extinguishing. That is, the plasma generation system can know that the plasma power will no longer be at, for example, t 4 In some implementations, the controller can send a signal to the plasma generation system to, for example, continue to apply at t 4 , stop applying plasma power. In some cases, plasma extinguishing can be unintentional. In some implementations, one or more components (e.g., visual inertial sensors) in the processing chamber (including at the ESC) can detect the presence of plasma. In some implementations, a plasma emission detector can detect parameters related to the presence of plasma, such as the composition of the plasma or the concentration of one or more plasma species. In some implementations, a voltage and / or current sensor can monitor the voltage, current, or another parameter based on either or both (e.g., V / I) of the RF power delivered to the plasma generator system, for example, to determine the plasma state. In some implementations, the flow (e.g., flow rate) of the gas can be monitored by a mass flow controller such as the gas distribution system 177.

[0084] In response to detecting that a parameter is below or does not meet a desired threshold (e.g., the presence of plasma or a substance or gas, a flow rate or state of a mass flow controller of the gas distribution system 177), the ESC can switch from the monopolar clamping mode 504 to the bipolar clamping mode 502 to prevent discharge or to keep the wafer clamped and stable to prevent the wafer from slipping or falling off the ESC or susceptor. This switching can be performed independently of any transmitted signal (e.g., by the controller) to reduce plasma power, for example, during an unexpected plasma extinction.

[0085] Similarly, before switching to the monopolar clamping mode 504 (according to, for example, Figure 5A 500), the plasma generation system may anticipate or know that the plasma power will be at t 0 Based on this and / or based on the presence of the plasma, the ESC can switch from the bipolar clamping mode 502 to the monopolar clamping mode 504.

[0086] Thus, in some implementations, the bipolar clamping mode of the ESC and the application of plasma power can partially overlap, while the monopolar clamping mode of the ESC and the application of plasma power can completely overlap. method

[0087] Figure 6 6 is a flow chart that depicts a method 600 for operating an electrostatic chuck (ESC) according to some embodiments. One or more functions in the method 600 may be performed by a computerized device or system. Figure 6 The means for performing the functions depicted in one or more steps shown in the figure may include hardware and / or software components of such a computerized device or system (e.g., a control device, a computerized system, or a computer-readable device including a storage medium storing computer-readable and / or computer-executable instructions, which are configured to cause at least one processor device or another device to perform these operations when executed by a processor device. A controller may be an example of a computerized device or system. An ESC may be another example of a computerized device or system. A processing chamber may be another example of a computerized device or system. Figure 1 , exemplary components of a processing chamber (including a controller) and an ESC are depicted in FIG. 1 , which are described in detail above.

[0088] It should also be noted that the operations of method 600 may be performed in any suitable order, not necessarily in the order in which they are performed. Figure 6 In addition, method 600 may include Figure 6 More or less operations may be performed as shown to perform the ESC operation.

[0089] At step 602, method 600 may include operating an electrostatic chuck (ESC) in a first clamping mode. In some embodiments, the ESC may be Figure 1 An example of an ESC 102 is shown in FIG. In some embodiments, the ESC may include multiple clamping electrodes, such as Figure 1. In some configurations, the ESC may use a pair of clamping electrodes that are configured to have high voltages of opposite polarity or the same polarity. For example, during operation of the ESC, the first of the pair of clamping electrodes may have a voltage of -500V, while the second of the pair of clamping electrodes may have a voltage of +500V. In some configurations, the voltage of both clamping electrodes may be +500V.

[0090] When the clamping electrodes have opposite polarities, the ESC can be considered to be operating in a bipolar clamping mode. When the clamping electrodes have the same polarity, the ESC can be considered to be operating in a monopolar clamping mode. In some cases, a plasma may already be ignited in the processing chamber where the ESC is located, which can allow the clamping electrodes to be used with the same polarity and the ESC to be used in a monopolar clamping mode.

[0091] In some embodiments, operating the ESC in the first clamping mode may include operating the ESC in a bipolar clamping mode. The bipolar clamping mode may use the above-described Figures 4A to 4D In some embodiments, operating the ESC in the first mode may include operating the ESC in a monopolar clamping mode. The monopolar clamping mode may be implemented using any configuration described above with respect to Figures 4A to 4D In some cases, the bipolar clamping mode or the monopolar clamping mode may be an initial mode during activation of a substrate (e.g., a wafer on which processing and operation are performed). In some cases, the bipolar clamping mode or the monopolar clamping mode may be switched from a previous monopolar clamping mode or the bipolar clamping mode.

[0092] In some embodiments, the first clamping mode includes using bipolar clamping or monopolar clamping to clamp the substrate to the ESC.

[0093] At step 604, method 600 may include operating the ESC in a second clamping mode. In some embodiments, operation of the second clamping mode may depend at least on changes in the substrate processing environment (e.g., processing chamber 100). In some embodiments, operating the ESC in the second clamping mode may include switching from the first clamping mode during operation of the ESC in the first clamping mode. Figure 5A and 5BAs shown, there may be a period of overlap between the operation of the first and second modes. In some embodiments, the transition to the second clamping mode may be achieved by using multiple power sources. For example, the configuration described with respect to FIGS. 2 and 3 may allow the use of multiple electrodes to switch between a bipolar clamping mode and a monopolar clamping mode. In some cases, the second clamping mode may occur at a point in time after a change in the substrate processing environment. As an example of a change in the substrate processing environment, please refer back to Figure 5A and 5B , which may be a situation where the plasma at t 0 Ignition, or plasma at t 4 extinguished, but unipolar clamping can be 1 (At t 0 After that) and bipolar clamping can be performed at t 3 (At t 4 before) to ensure that monopolar clamping is used when plasma is present.

[0094] In some embodiments, the substrate processing environment may include the presence of plasma, the composition of the plasma and / or the concentration of one or more plasma species. If the substrate processing environment changes, such as an increase in plasma is detected, the ESC may switch to operate in a second clamping mode. In some embodiments, a monopolar clamping mode may be suitable in the presence of plasma. Therefore, in these implementations, operating the ESC in the second clamping mode may include switching the ESC from a bipolar clamping mode as the first clamping mode to a monopolar clamping mode for operation. Monopolar clamping may better ensure uniformity of the substrate and reduce the risk of damage to chamber components and parasitic plasma formation.

[0095] If the plasma is extinguished, the ESC can switch to a bipolar clamping mode. Bipolar clamping can reduce the risk of de-clamping associated with monopolar clamping. Therefore, in some embodiments, operating the ESC in the second clamping mode may include switching the ESC from the monopolar clamping mode as the first clamping mode to operate in a bipolar clamping mode.

[0096] In some embodiments, the second clamping mode includes clamping the substrate to the ESC using a different bipolar clamping or monopolar clamping approach than the first clamping mode.

[0097] In some embodiments, changes to the substrate processing environment may include signals from a controller.A controller (eg, controller 111, 302, 312) may provide instructions to one or more power sources to provide appropriate voltages.

[0098] In some embodiments, the basis for changes to the substrate processing environment can include anticipated future changes to the substrate processing environment. For example, in a processing cycle where plasma is introduced or removed at predefined intervals or repeated steps, or in a processing step with a predetermined exposure length of the substrate to the plasma, or depending on the type or characteristics of the film being formed or the wafer being used, it may be known that monopolar clamping or bipolar clamping may be more appropriate for clamping the substrate during a particular portion of the process.

[0099] The switching time between bipolar clamping mode and monopolar clamping mode can be seen at Figure 5A and 5B It should be noted that bipolar clamping can be performed with or without the presence of a plasma. However, monopolar clamping involves the presence of a plasma. According to various embodiments, operating the ESC in the second clamping mode can be performed in the presence of a plasma. In some cases, the first and second clamping modes can be operated during an overlapping period of time (e.g., at t 1 and t 2 Between, or at t 3 and t 4 or 5 to achieve a transition period instead of a sudden change in clamping mode.

[0100] Optionally, in step 606, method 600 can continue to operate the ESC in the first clamping mode. In some embodiments, operation of the ESC can be switched back to the first clamping mode based on at least another change in the substrate processing environment. The switching back action can occur during operation in the second clamping mode. In some embodiments, the change in the substrate processing environment can be opposite to the change in step 604. For example, a plasma reduction may be detected or expected.

[0101] Figure 7 is a flow chart depicting another method 700 of operating an electrostatic chuck (ESC) according to some embodiments. One or more functions of the method 700 may be performed by a computerized device or system. Figure 7 The means for performing the functions depicted in one or more steps shown in may include hardware and / or software components of such a computerized device or system (e.g., a control device, a computerized system, or a computer-readable device including a storage medium storing computer-readable and / or computer-executable instructions, wherein the instructions are configured to cause at least one processor device or another device to perform these operations when executed by a processor device. A controller may be an example of a computerized device or system. An ESC may be another example of a computerized device or system. A processing chamber may be another example of a computerized device or system. Figure 1 , exemplary components of a processing chamber (including a controller) and an ESC are depicted in FIG. 5 , which are described in detail above.

[0102] It should also be noted that the operations of method 700 may be performed in any suitable order, not necessarily in the order in which they are performed. Figure 7 In addition, method 700 may include: Figure 7 More or less operations may be performed as shown to perform the ESC operation.

[0103] At step 702, method 700 may include providing a substrate to a processing chamber and placing the substrate on a susceptor. In some embodiments, the substrate may include a silicon-based or other semiconductor wafer on which operations may be performed, and the processing chamber may be about Figure 1 An example of a processing chamber 100 is shown. In some embodiments, the pedestal can include an electrostatic chuck (ESC).

[0104] At step 704, method 700 can include exposing the substrate to a substrate processing environment in preparation for processing. In some embodiments, the substrate processing environment can include a plasma formed near the substrate (eg, above a wafer).

[0105] At step 706, method 700 may include clamping the substrate to the susceptor using a bipolar clamp. In some embodiments, two electrodes (e.g., Figure 1 Figure 2 Figure 3A or Figure 3B In some embodiments, bipolar clamping can be performed using electrodes such as those shown in FIG. Figure 3A and Figure 3B The multiple power sources shown in can be used to achieve bipolar clamping. For example, two power sources electrically coupled to respective electrodes can power respective electrodes by providing voltages of opposite polarities.

[0106] At step 708, method 700 may include clamping the substrate to the susceptor using monopolar clamping. In some embodiments, the susceptor clamping performed using monopolar clamping may depend at least on changes in the substrate processing environment. In certain embodiments, the use of monopolar clamping may include switching from bipolar clamping during operation of the ESC using bipolar clamping. Figure 5A and 5B As shown, there may be a period of overlap in the operation of the bipolar and monopolar modes. In some embodiments, the change in the substrate processing environment may include the detection or anticipation of the introduction of a plasma into the processing chamber (e.g., the plasma ignition). In some cases, the monopolar clamping may occur at a point in time after the substrate processing environment has changed. For example, referring back to Figure 5A , which may be a situation where the plasma at t 0 ignition, but unipolar clamping occurs at t 1 When (at t0 after), to ensure that plasma is present before switching to unipolar clamping involving the presence of plasma.

[0107] In some embodiments, two electrodes may be used to perform monopolar clamping. In some embodiments, one electrode may be used to perform monopolar clamping (e.g., the outer electrode of two concentric electrodes may be powered, while the inner electrode is not powered). In some implementations, multiple (e.g., two) power sources may be utilized. In some implementations, one power source may be utilized.

[0108] Optionally, at step 710, method 700 can include clamping the substrate to the pedestal using bipolar clamping. In some embodiments, this can depend on at least another change in the substrate processing environment. In some embodiments, this change in the substrate processing environment can be opposite to the change in step 708. For example, plasma reduction (e.g., quenching) may occur, be detected, or be expected to occur.

[0109] Figure 8 is a flow chart depicting another method 800 of operating an electrostatic chuck (ESC) according to some embodiments. One or more functions of the method 800 may be performed by a computerized device or system. Figure 8 The means for performing the functions depicted in one or more steps shown in may include hardware and / or software components of such a computerized device or system (e.g., a control device, a computerized system, or a computer-readable device including a storage medium storing computer-readable and / or computer-executable instructions, wherein the instructions are configured to cause at least one processor device or another device to perform these operations when executed by a processor device. A controller may be an example of a computerized device or system. An ESC may be another example of a computerized device or system. A processing chamber may be another example of a computerized device or system. Figure 1 , exemplary components of a processing chamber (including a controller) and an ESC are depicted, which are described in detail above.

[0110] It should also be noted that the operations of method 800 may be performed in any suitable order, not necessarily in the order in which they are performed. Figure 8 In addition, method 800 may include Figure 8 More or less operations may be performed as shown to perform the ESC operation.

[0111] In step 802, method 800 may include providing a substrate to a processing chamber and placing the substrate on a susceptor. In step 804, method 800 may include exposing the substrate to a substrate processing environment in preparation for processing. Steps 802 and 804 may correspond to and involve operations substantially similar to steps 702 and 704.

[0112] At step 806, method 800 may include clamping the substrate to the pedestal using a monopolar clamp. In some cases, the manufacturing process of the substrate may be initiated by igniting a plasma in the processing chamber prior to clamping the substrate. In this case, either a bipolar clamp or a monopolar clamp may be used. Nevertheless, in some embodiments, a monopolar clamp may be used, for example, depending on the type of film or wafer used (e.g., wafers are prone to non-uniformity issues), or if power usage can be reduced when a single electrode configuration is used. In some embodiments, a plurality of (e.g., two) electrodes may be used for monopolar clamping (e.g., the same voltage may be applied to each electrode). In some embodiments, a respective power source may be used to power a plurality of (e.g., two) electrodes.

[0113] However, in some embodiments, a single electrode can be used to achieve monopolar clamping. In some embodiments, a single power source can be used. In some implementations, a single power source can be used to power a single electrode or multiple (e.g., two) electrodes.

[0114] At step 808, method 800 may include clamping the substrate to the susceptor using bipolar clamping. In some embodiments, the susceptor clamping performed using bipolar clamping may depend at least on changes in the substrate processing environment. In certain implementations, the use of bipolar clamping may include switching from monopolar clamping during operation of the ESC using monopolar clamping. Figure 5A and 5B As shown, the overlap of bipolar and monopolar modes of operation may exist for a period of time. In some embodiments, the change in the substrate processing environment may include the detection or anticipation of plasma removal in the processing chamber (e.g., plasma extinguishing). In some cases, the bipolar clamping may occur at a point in time before the change in the processing environment. For example, referring back to Figure 5B , which may be a situation where the plasma at t 4 extinguished, but bipolar clamping occurs at t 3 When (at t 4 before) to ensure that arcing does not occur while the wafer is still clamped, or to ensure that the wafer does not slip.

[0115] In some embodiments, two electrodes may be used to perform bipolar clamping. In some implementations, multiple (e.g., two) power sources may be utilized. In some implementations, one power source may be utilized.

[0116] Optionally, at step 810, method 800 can include clamping the substrate to the pedestal using a monopolar clamp. In some embodiments, this can depend on at least another change in the processing environment. In some embodiments, this change in the processing environment can be opposite to the change in step 808. For example, a plasma increase (e.g., plasma ignition) may occur, be detected, or be expected to occur.

[0117] In some implementations, the controller (e.g., 111, 302, 312) is part of a system and the system may be part of the above examples, including a processing chamber or another system including an ESC. Such a system may include a semiconductor processing device, which includes one or more processing tools, one or more chambers, one or more platforms for processing, and / or specific processing components (wafer pedestals, gas flow systems, etc.). These systems can be integrated with electronic devices for controlling their operation before, during, and after the processing of semiconductor wafers or substrates. The electronic device may be referred to as a "controller" which can control various components or subcomponents of one or more systems. Depending on the processing requirements and / or the type of system, the controller may be programmed to control any of the processes disclosed herein, including the delivery of process gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings in some systems, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, position and operation settings, wafer transfer in and out of tools connected or docked with a specific system and other transfer tools and / or load locks.

[0118] In general, a controller can be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receive instructions, issue instructions, control operations, enable cleaning operations, enable endpoint measurements, etc. The integrated circuit can include a chip in the form of firmware that stores program instructions, a digital signal processor (DSP), a chip defined as an application specific integrated circuit (ASIC), and / or one or more microprocessors or microcontrollers that execute program instructions (e.g., software). The program instructions can be instructions sent to the controller in the form of various individual settings (or program files) that define operating parameters for performing specific processing on or for a semiconductor wafer or system. In some embodiments, the operating parameters can be part of a recipe defined by a process engineer to complete one or more processing steps during processing of one or more (kinds of) layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of a wafer.

[0119] In some implementations, the controller may be part of or coupled to a computer that is integrated with the system, coupled to the system, otherwise networked to the system, or a combination thereof. For example, the controller may be in the "cloud" or may be all or part of a wafer fab host system that may allow remote access to wafer processing. The computer may enable remote access to the system to monitor the current progress of a processing operation, check the history of past processing operations, check trends or performance criteria for multiple processing operations, to change the parameters of the current processing, set processing steps to follow the current processing, or start a new processing. In some examples, a remote computer (e.g., a server) may provide a processing recipe to the system via a network (which may include a local network or the Internet). The remote computer may include a user interface that enables input or programming of parameters and / or settings, which are then sent from the remote computer to the system. In some examples, the controller receives instructions in the form of data that specify the parameters of each processing step to be performed during one or more operations. It should be understood that the parameters may be specific to the type of processing to be performed and the type of tool that the controller is configured to interface with or control. Thus, as described above, the controller may be distributed, for example, by including one or more discrete controllers networked together and working toward a common purpose (e.g., processing and control as described herein). An example of a distributed controller for such a purpose is one or more integrated circuits on a chamber that communicate with one or more integrated circuits remotely (e.g., at a platform level or as part of a remote computer), which combine to control processing on the chamber.

[0120] Exemplary systems may include, but are not limited to, plasma etching chambers or modules, deposition chambers or modules, spin rinse chambers or modules, metal plating chambers or modules, cleaning chambers or modules, chamfer edge etching chambers or modules, physical vapor deposition (PVD) chambers or modules, chemical vapor deposition (CVD) chambers or modules, atomic layer deposition (ALD) chambers or modules, atomic layer etching (ALE) chambers or modules, ion implantation chambers or modules, track chambers or modules, and any other semiconductor processing system that may be associated with or used for processing and / or preparing semiconductor wafers.

[0121] As described above, depending on one or more processing steps to be performed by the tool, the controller can communicate with one or more other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout the factory, a host computer, another controller, or tools used in material transport to transport wafer containers to and from tool locations and / or load ports in a semiconductor manufacturing facility.

[0122] A system and method are now provided that provide improved clamping or clamping performance over conventional systems. The methods, devices, and systems described above enable the flexible use of various clamping modes (e.g., bipolar and / or monopolar) compared to conventional systems, and achieve this goal while using modifications to the prior art. Thus, embodiments of the improved clamping system now include configurations involving one or more power sources.

[0123] Various modifications of the implementations described in this disclosure may be apparent to those skilled in the art, and the general principles defined herein may be applied to other implementations without departing from the spirit or scope of the disclosure. Therefore, the claims are not intended to be limited to the implementations shown herein, but are to be consistent with the broadest scope consistent with the disclosure, the principles and novel features disclosed herein.

[0124] Certain features described in this specification in the context of separate implementations may also be implemented in combination in a single implementation. Conversely, various features described in the context of a single implementation may also be implemented in multiple implementations, either individually or in any suitable subcombination. Furthermore, while features may be described above as functioning in a particular combination, or even initially claimed as such a combination, in some cases one or more features may be removed from the combination, and the claimed combination may be directed to subcombinations or variations of subcombinations.

[0125] Similarly, although the operations are depicted in a particular order in the figure, this should not be understood as requiring these operations to be performed in the particular order shown or in a continuous order, or requiring the execution of all depicted operations to achieve the desired result. In addition, the figure may schematically depict one or more exemplary processes in the form of a flow chart. However, other operations that are not depicted can be incorporated into the example processing schematically depicted. For example, before, after, at the same time or between any depicted operations, one or more additional operations can be performed. In some cases, multitasking and parallel processing may be advantageous. In addition, in the implementation scheme described above, the separation of various system components should not be understood as requiring such separation to be achieved in all implementation schemes, and it should be understood that the program components and systems described can usually be integrated in a single software product or packaged into multiple software products. In addition, other implementation schemes also fall within the scope of the following claims. In some cases, the actions described in the claims can be performed in different orders, and the desired results can still be achieved.

Claims

1. A system configured to operate an electrostatic chuck (ESC) in multiple modes, the system include: a plurality of clamping electrodes associated with the ESC; a plurality of power sources electrically coupled to the plurality of clamping electrodes; a controller coupled to the plurality of power sources, wherein the controller is configured to: clamping a substrate on the ESC using a first clamping mode, the first clamping mode comprising a first configuration of the plurality of clamping electrodes and the plurality of power sources; as well as During operation of the ESC using the first clamping mode, switching from the first clamping mode to clamp the substrate on the ESC using a second clamping mode, the second clamping mode comprising a second configuration of the plurality of clamping electrodes and the plurality of power sources, the second configuration being different from the first configuration.

2. The system according to claim 1, in: The first clamping mode comprises a bipolar clamping mode; and The second clamping mode includes a monopolar clamping mode.

3. The system according to claim 1, in: The first clamping mode comprises a monopolar clamping mode; and The second clamping mode comprises a bipolar clamping mode.

4. The system according to claim 3, in: The plurality of clamping electrodes include a first clamping electrode and a second clamping electrode; The plurality of power sources include a first power source and a second power source; and The bipolar clamping mode includes causing the first power source to supply a first voltage of a first polarity to the first clamping electrode, and causing at least the second power source to supply a second voltage of a second polarity to the second clamping electrode, the second polarity being opposite to the first polarity.

5. The system according to claim 3, in: The plurality of clamping electrodes include a first clamping electrode and a second clamping electrode; The plurality of power sources include a first power source and a second power source; and The monopolar clamping mode includes causing the first power source to supply a first voltage of a first polarity to the first clamping electrode, and causing at least the second power source to supply the first voltage of the first polarity to the second clamping electrode.

6. The system according to claim 1, in, The switching from the first clamping mode to the second clamping mode depends on changes in processing conditions.

7. The system according to claim 6, in, The changing of the processing environment includes introducing plasma into the processing chamber.

8. The system according to claim 6, in, The change in the processing environment includes a signal from the controller.

9. The system according to claim 6, in: The changing of the processing environment includes introducing plasma into the processing chamber; and The switching from the first chucking mode to the second chucking mode is configured to occur in response to introduction of the plasma into the processing chamber.

10. The system according to claim 9, in: The controller is further configured to switch from the second clamping mode to clamp the substrate on the ESC using the first clamping mode based on a second change in the processing environment; The second change of the processing environment includes plasma removal; and The switching from the second chucking mode to the first chucking mode is configured to occur within a period of time before the plasma removal.

11. A method of operating an electrostatic chuck (ESC) in multiple modes, the method include: operating the ESC in a first clamping mode; as well as operating the ESC in a second clamping mode based on a change in process environment during a portion of the operation in the first clamping mode; Wherein each of the first clamping mode and the second clamping mode comprises clamping a substrate on the ESC using a corresponding configuration of clamping electrodes associated with the ESC.

12. The method according to claim 11, in, The first clamping mode comprises a bipolar clamping mode of the ESC, and the second clamping mode comprises a monopolar clamping mode of the ESC.

13. The method according to claim 12, in: The bipolar clamping mode includes supplying a first voltage of a first polarity to a first clamping electrode of the ESC and supplying a second voltage of a second polarity to a second clamping electrode of the ESC, the second polarity being opposite to the first polarity; as well as The monopolar clamping mode includes supplying the first voltage of the first polarity to the first clamping electrode and the second clamping electrode of the ESC.

14. The method according to claim 11, in, The first clamping mode comprises a monopolar clamping mode of the ESC, and the second clamping mode comprises a bipolar clamping mode of the ESC.

15. The method according to claim 14, in: The bipolar clamping mode includes supplying a first voltage of a first polarity to a first clamping electrode of the ESC and supplying a second voltage of a second polarity to a second clamping electrode of the ESC, the second polarity being opposite to the first polarity; as well as The monopolar clamping mode includes supplying the first voltage of the first polarity to the first clamping electrode and the second clamping electrode of the ESC.

16. The method according to claim 11, in, The changing of the processing environment includes the introduction of plasma into the processing environment, or the removal of plasma from the processing environment.

17. An electrostatic chuck (ESC) capable of operating in a substrate processing environment, the ESC include: a first clamping electrode electrically coupled to a first power source; as well as a second clamping electrode electrically coupled to a second power source; Wherein, the ESC is configured as follows: clamping a substrate on the ESC using a first clamping mode; and switching during a portion of the first clamping mode to clamp the substrate to the ESC using a second clamping mode; wherein the first clamping mode includes receiving a first voltage from the first power source at the first clamping electrode, and receiving a second voltage from the second power source at the second clamping electrode, the first voltage and the second voltage having opposite polarities; and The second clamping mode includes receiving a voltage from the first power source at the first clamping electrode and receiving a voltage from the second power source at the second clamping electrode.

18. The ESC according to claim 17, in, The ESC is further configured to clamp the substrate on the ESC using the second clamping mode based at least on a change in the substrate processing environment.

19. The ESC according to claim 18, in, The change in the substrate processing environment includes the introduction of plasma into the processing environment, or the removal of plasma from the substrate processing environment.

20. The ESC according to claim 17, in, The clamping of the substrate using the second clamping mode is configured to occur within a predetermined time before or after a change in the substrate processing environment.

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