Patent ID: 12217944

In the drawings, reference numbers may be reused to identify similar and/or identical elements.

DETAILED DESCRIPTION

A processing chamber of a substrate processing system may include heated components including, but not limited to, an electrode (e.g., a ceramic layer or other heated layer of a substrate support), an edge ring of the substrate support, etc. A radio frequency (RF) plasma environment such as a processing chamber may include one or more high power cable and filter systems to provide direct current (DC) or low frequency (e.g., 47 Hz-400 Hz) power to the heated electrode and/or edge ring. For example only, the delivered power may range from 1 watt to several kilowatts (e.g., 8 kilowatts).

In some examples, two or more components (e.g., both the electrode and the edge ring) are heated. For example, heating elements may be integrated within the electrode and/or edge ring. Power is supplied to the heating elements of the edge ring and the electrode via respective (i.e., multiple) cable and filter systems. Multiple cable and filter systems increase cost and manufacturing complexity and occupy a larger space within the substrate support.

RF power is also supplied (e.g., via an RF generating/power delivery system) to a conductive baseplate of the substrate support to generate plasma within the processing chamber. In some examples, coupling characteristics of respective heating elements of the electrode and the edge ring may be similar such that their respective impedances relative to the RF generating system are also similar. However, electrode and edge ring heating elements may cause local resonances around operating frequencies of the RF generating system, causing an impedance shift. Such an impedance shift may impair the operation of the RF generating system. For example, the impedance shift may draw power away from plasma generation, reduce etch rates by 15-60%, cause wafer non-uniformity, etc.

A combined heater and filter system according to the principles of the present disclosure is configured to compensate for impedances present in and around a heated electrode and edge ring in a substrate processing system. For example, the cable delivery and filter system may include a single power delivery cable provided between a common filter and the substrate support to deliver power to the heating elements of both the electrode and the edge ring. In some examples, the system may include an RF blocking or isolation device (e.g., an inductor having a value selected according to various impedances of the system) to increase the impedance at the edge ring. In this manner, low frequency or DC power may be provided to power the heating elements without interfering with the RF generating system.

Referring now toFIG.1, an example substrate processing system100is shown. For example only, the substrate processing system100may be used for performing etching using RF plasma and/or other suitable substrate processing. The substrate processing system100includes a processing chamber102that encloses other components of the substrate processing system100and contains the RF plasma. The substrate processing chamber102includes an upper electrode104and a substrate support106, such as an electrostatic chuck (ESC). During operation, a substrate108is arranged on the substrate support106. While a specific substrate processing system100and chamber102are shown as an example, the principles of the present disclosure may be applied to other types of substrate processing systems and chambers, such as a substrate processing system that generates plasma in-situ, that implements remote plasma generation and delivery (e.g., using a plasma tube, a microwave tube), etc.

For example only, the upper electrode104may include a gas distribution device such as a showerhead109that introduces and distributes process gases. The showerhead109may include a stem portion including one end connected to a top surface of the processing chamber. A base portion is generally cylindrical and extends radially outwardly from an opposite end of the stem portion at a location that is spaced from the top surface of the processing chamber. A substrate-facing surface or faceplate of the base portion of the showerhead includes a plurality of holes through which process gas or purge gas flows. Alternately, the upper electrode104may include a conducting plate and the process gases may be introduced in another manner.

The substrate support106includes a conductive baseplate110. The baseplate110supports a ceramic layer112. In some examples, the ceramic layer112may comprise a heating layer, such as a ceramic multi-zone heating plate. A thermal resistance layer114(e.g., a bond layer) may be arranged between the ceramic layer112and the baseplate110. The baseplate110may include one or more coolant channels116for flowing coolant through the baseplate110. The conductive baseplate110and the ceramic layer112act as a lower electrode.

An RF generating system120generates and provides RF power (e.g., as a voltage source, current source, etc.) to one of the upper electrode104and the lower electrode (e.g., the baseplate110of the substrate support106). For example purposes only, the output of the RF generating system120will be described herein as an RF voltage. The other one of the upper electrode104and the baseplate110may be DC grounded, AC grounded or floating. As shown, the RF generating system provides the RF voltage to the baseplate110corresponding to the lower electrode. For example only, the RF generating system120may include an RF voltage generator122that generates the RF voltage that is fed by a matching and distribution network124to the upper electrode104or the baseplate110. In other examples, the plasma may be generated inductively or remotely. Although, as shown for example purposes, the RF generating system120corresponds to a capacitively coupled plasma (CCP) system, the principles of the present disclosure may also be implemented in other suitable systems, such as, for example only transformer coupled plasma (TCP) systems, CCP cathode systems, remote microwave plasma generation and delivery systems, etc.

A gas delivery system130includes one or more gas sources132-1,132-2, . . . , and132-N (collectively gas sources132), where N is an integer greater than zero. The gas sources supply one or more precursors and mixtures thereof. The gas sources may also supply purge gas. Vaporized precursor may also be used. The gas sources132are connected by valves134-1,134-2, . . . , and134-N (collectively valves134) and mass flow controllers136-1,136-2, . . . , and136-N (collectively mass flow controllers136) to a manifold140. An output of the manifold140is fed to the processing chamber102. For example only, the output of the manifold140is fed to the showerhead109.

A temperature controller142may be connected to a plurality of heating elements144, such as thermal control elements (TCEs) arranged in the ceramic layer112. For example, the heating elements144may include, but are not limited to, macro heating elements corresponding to respective zones in a multi-zone heating plate and/or an array of micro heating elements disposed across multiple zones of a multi-zone heating plate. The temperature controller142may be used to control the plurality of heating elements144to control a temperature of the substrate support106and the substrate108. For example, the temperature controller142may correspond to a power supply, and/or may control a power supply (not shown) external to the temperature controller142to provide power to the heating elements144.

The temperature controller142may communicate with a coolant assembly146to control coolant flow through the channels116. For example, the coolant assembly146may include a coolant pump and reservoir. The temperature controller142operates the coolant assembly146to selectively flow the coolant through the channels116to cool the substrate support106.

A valve150and pump152may be used to evacuate reactants from the processing chamber102. A system controller160may be used to control components of the substrate processing system100. A robot170may be used to deliver substrates onto, and remove substrates from, the substrate support106. For example, the robot170may transfer substrates between the substrate support106and a load lock172. Although shown as separate controllers, the temperature controller142may be implemented within the system controller160. In some examples, a protective seal176may be provided around a perimeter of the bond layer114between the ceramic layer112and the baseplate110.

The substrate support106includes an edge ring180. The edge ring180may correspond to a top ring, which may be supported by a bottom ring184. The edge ring180may include one or more heating elements188. Accordingly, the temperature controller142may control power delivered to both the heating elements144of the ceramic layer112as well as the heating elements188of the edge ring180. In the substrate processing system100according to the principles of the present disclosure, the temperature controller142provides power to the heating elements144and188via a shared cable and filter system (e.g., including a common filter module, not shown inFIG.1, and power delivery cable192) as described below in more detail.

Referring now toFIG.2, a simplified example substrate support200including a cable and filter system (which may be referred to simply as “the cable”)204according to the principles of the present disclosure is shown in more detail. The substrate support200includes a conductive baseplate208and a ceramic layer212(together corresponding to a lower electrode) including one or more heating elements216. An edge ring220is arranged to surround the ceramic layer212and includes one or more heating elements224. As shown, the ceramic layer212includes four of the heating elements216(e.g., corresponding to an inner zone, a middle inner zone, a middle outer zone, and an outer zone of a plurality of concentric annular zones) and the edge ring220includes one of the heating elements224. In some examples, the baseplate208may be arranged on an insulating ring226.

The cable and filter system204provides power (e.g., DC or low frequency AC voltage) from a heating element power source228to the heating elements216and224. For example only, the heating element power source228corresponds to a power source controlled by the temperature controller142ofFIG.1. Conversely, an RF power source232provides RF power to the conductive baseplate208via RF delivery line236(e.g., a coaxial wire, an RF hollow tube system, etc.). For example, the RF power source232corresponds to the RF generating system120ofFIG.1. In some configurations, proximity between the cable204, the RF delivery line236, the heating elements216and224, and/or other components within the substrate support200may interfere with delivery of RF power. For example, components of the cable204and the heating elements216and224may cause local resonances around operating frequencies of the RF power provided to the baseplate208, causing RF power to be drawn out of the baseplate208. Accordingly, the cable204according to the present disclosure implements various features to compensate for these local resonances.

The cable and filter system204includes a filter module240and a plurality of (e.g., ten) wires244for providing power to the heating elements216and224. For example, the plurality of wires244includes a pair of wires248for providing power to the heating element224of the edge ring220and four pairs of wires252for providing power to the heating elements216of the ceramic layer212. The plurality of wires244may be twisted together in a first portion256of the cable204from the heating element power source228to, and inside of, the filter module240(e.g., from outside of the substrate support200to an interior258of the substrate support200). In some examples, the filter module240includes, inter alia, a main filtering inductor corresponding to the twisted together wires244coiled around an inductor core. An example filter system can be found in U.S. Pat. Pub. No. 2016/0028362, which is incorporated herein in its entirety.

Within the substrate support200, the wires248are separated from the wires252(i.e., removed from the twisted plurality of wires244) to be routed through the substrate support200to the heating element224of the edge ring220. Conversely, the wires252are routed through the substrate support200to the heating elements216of the ceramic layer212. In the cable and filter system204according to the principles of the present disclosure, the separated wires248implement a frequency isolation or cancellation device260as described below in more detail.

Referring now toFIG.3and with continued reference toFIG.2, an example circuit schematic300of the cable and filter system204according to the present disclosure is shown. As one example, local resonance frequencies may be generated between circuit loops304and308. For example, the local resonance frequencies may be caused in part by coupling between the heating elements224of the edge ring220and the baseplate208etc. (e.g., due to capacitance coupling between the baseplate208and other structures as indicated by various capacitances312). Accordingly, the isolation device260is provided to compensate for (e.g., cancel out, isolate, block, etc.) the generated resonance frequencies to preserve the desired RF power delivered to the baseplate208.

In one example (as shown), the isolation device260corresponds to an inductor316. For example, the separated wires248may be twisted together and coiled around an inductor core, air wound, etc. The inductor core may be dielectric, conductive, magnetic (ferrite, ferrite bead, iron), etc. In this example, an impedance of the isolation device260is selected according to the generated resonance frequency (e.g., by selecting an inductance value of the inductor316to achieve a desired impedance). In other words, the impedance of the isolation device260is selected to compensate for the generated resonance frequency (e.g., by cancelling the resonance frequency, shifting the resonance frequency to a different band relative to an operating frequency of the RF power, etc.). For example, the impedance may be selected according to the capacitances312, an inductance of the edge ring220, inductances of wires within the loops304and308(e.g., inductances of the wires248and selected ones of the wires252nearest to the wires248within the substrate support200), an inductance of a main inductor320of the filter module240, etc.

Although described above in an example as an inductor316, other implementations of the isolation device260may be used. For example, the isolation device260may include a T network, additional inductors, an inductor/capacitor circuit, a transformer/inductor circuit, etc. In some examples, a capacitance of the edge ring220may be increased. Accordingly, in the above example, the inductance value of the inductor316may be selected according to the desired impedance of the isolation device260to compensate for the generated resonance frequency while in other examples, other characteristics (e.g., resistances of a T network, transformer characteristics, inductance and/or capacitance values, etc.) of the isolation device260may be selected to achieve the desired impedance.

Referring now toFIG.4A, an example cable400corresponding to the cable and filter system204ofFIGS.2and3is shown. The cable400is shown schematically inFIG.4B. In this example, the cable400includes ten wires (e.g., two wires404-1configured to provide power to a heating element of an edge ring and eight wires404-2configured to provide power to heating elements of a substrate support, referred to collectively as wires404). The cable400includes connector408configured to connect to a power source external to the substrate support (e.g., the heating element power source228). A first portion412of the cable400includes a filter module416. The wires404are twisted together in the filter module416. For example, the wires404are twisted together in a coaxial manner around a core (e.g., an inductor core, a fiberglass core, etc.).

In a second portion420of the cable400, the wires404-1are separated from the wires404-2and connected to an isolation device424. The isolation device424includes structure (e.g., one or more inductors, a T network, an inductor/capacitor circuit, a transformer/inductor circuit, etc.) configured to compensate for resonance frequencies as described above inFIGS.2and3. Ends of each of the wires404may include pins428configured to connect the wires404to terminals of respective heating elements of the substrate support. Portions of the cable400may include one or more layers of insulation432.

The foregoing description is merely illustrative in nature and is in no way intended to limit the disclosure, its application, or uses. The broad teachings of the disclosure can be implemented in a variety of forms. Therefore, while this disclosure includes particular examples, the true scope of the disclosure should not be so limited since other modifications will become apparent upon a study of the drawings, the specification, and the following claims. It should be understood that one or more steps within a method may be executed in different order (or concurrently) without altering the principles of the present disclosure. Further, although each of the embodiments is described above as having certain features, any one or more of those features described with respect to any embodiment of the disclosure can be implemented in and/or combined with features of any of the other embodiments, even if that combination is not explicitly described. In other words, the described embodiments are not mutually exclusive, and permutations of one or more embodiments with one another remain within the scope of this disclosure.

Spatial and functional relationships between elements (for example, between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including “connected,” “engaged,” “coupled,” “adjacent,” “next to,” “on top of,” “above,” “below,” and “disposed.” Unless explicitly described as being “direct,” when a relationship between first and second elements is described in the above disclosure, that relationship can be a direct relationship where no other intervening elements are present between the first and second elements, but can also be an indirect relationship where one or more intervening elements are present (either spatially or functionally) between the first and second elements. As used herein, the phrase at least one of A, B, and C should be construed to mean a logical (A OR B OR C), using a non-exclusive logical OR, and should not be construed to mean “at least one of A, at least one of B, and at least one of C.”

In some implementations, a controller is part of a system, which may be part of the above-described examples. Such systems can comprise semiconductor processing equipment, including a processing tool or tools, chamber or chambers, a platform or platforms for processing, and/or specific processing components (a wafer pedestal, a gas flow system, etc.). These systems may be integrated with electronics for controlling their operation before, during, and after processing of a semiconductor wafer or substrate. The electronics may be referred to as the “controller,” which may control various components or subparts of the system or systems. The controller, depending on the processing requirements and/or the type of system, may be programmed to control any of the processes disclosed herein, including the delivery of processing gases, temperature settings (e.g., heating and/or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, positional and operation settings, wafer transfers into and out of a tool and other transfer tools and/or load locks connected to or interfaced with a specific system.

Broadly speaking, the controller may be defined as electronics having various integrated circuits, logic, memory, and/or software that receive instructions, issue instructions, control operation, enable cleaning operations, enable endpoint measurements, and the like. The integrated circuits may include chips in the form of firmware 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 individual settings (or program files), defining operational parameters for carrying out a particular process on or for a semiconductor wafer or to a system. The operational parameters may, in some embodiments, be part of a recipe defined by process engineers to accomplish one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and/or dies of a wafer.

The controller, in some implementations, may be a 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 all or a part of a fab host computer system, which can allow for remote access of the wafer processing. The computer may enable remote access to the system to monitor current progress of fabrication operations, examine a history of past fabrication operations, examine trends or performance metrics from a plurality of fabrication operations, to change parameters of current processing, to set processing steps to follow a current processing, or to start a new process. In some examples, a remote computer (e.g. a server) can provide process recipes to a system over a network, which may include a local network or the Internet. The remote computer may include a user interface that enables entry or programming of parameters and/or settings, which are then communicated to the system from the remote computer. In some examples, the controller receives instructions in the form of data, which specify parameters for each of the processing steps to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process 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, such as by comprising one or more discrete controllers that are networked together and working towards a common purpose, such as the processes and controls described herein. An example of a distributed controller for such purposes would be one or more integrated circuits on a chamber in communication with one or more integrated circuits located remotely (such as at the platform level or as part of a remote computer) that combine to control a process on the chamber.

Without limitation, example systems may include a plasma etch chamber or module, a deposition chamber or module, a spin-rinse chamber or module, a metal plating chamber or module, a clean chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a track chamber or module, and any other semiconductor processing systems that may be associated or used in the fabrication and/or manufacturing of semiconductor wafers.

As noted above, depending on the process step or steps to be performed by the tool, the controller might communicate with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout a factory, a main computer, another controller, or tools used in material transport that bring containers of wafers to and from tool locations and/or load ports in a semiconductor manufacturing factory.