In-SITU cleaning of a vacuum transfer module end effector

Abstract

Disclosed is a method and apparatus configured to perform an in-situ plasma cleaning of an end effector. The method comprises moving the end effector into a process module from a vacuum transfer module attached to the process module, positioning the end effector below a gas distribution plate, flowing a plasma over the gas distribution plate, exposing the end effector to the plasma, and retracting the end effector into the vacuum transfer module.

Description

IN-SITU CLEANING OF A VACUUM TRANSFER MODULE END EFFECTORCLAIM FOR PRIORITY

[0001] This application claims priority to U.S. Provisional Patent Application No. 63 / 636,063, filed on April 18, 2024, titled “IN-SITU CLEANING OF A VACUUM TRANSFER MODULE END EFFECTOR,” and which is incorporated by reference in entirety.BACKGROUND

[0002] Substrate processing for etch and deposition form a backbone of the semiconductor industry. While a variety of processing techniques may be utilized, virtually all processes utilize a robot arm having an end effector method for transferring wafers into and out of a process chamber module from a vacuum transfer module that is communicatively coupled to one or more process chamber modules. The process chambers may be configured to perform deposition processes such as chemical vapor deposition (CVD) or plasma-enhanced chemical vapor deposition (PECVD) are performed. Over time, the end effector may be covered with carbon or other material that may be picked up from film particles from newly deposited films on wafers that come into contact with the end effector. The material can also accumulate on an end effector over time when the end effector is inserted into process chambers and may also accumulate particles in the process chamber that fall on it. This accumulated material can be further transferred to other wafers coming into contact with the end effector.BRIEF DESCRIPTION OF DRAWINGS

[0003] Material described herein is illustrated by way of example and not by way of limitation in accompanying figures. For simplicity and clarity of illustration, elements illustrated in figures are not necessarily drawn to scale. For example, dimensions of some elements may be exaggerated relative to other elements for clarity. Also, various physical features may be represented in their simplified “ideal” forms and geometries for clarity of discussion, but it is nevertheless to be understood that practical implementations may approximate illustrated ideals. For example, smooth surfaces and square intersections may be drawn in disregard of finite roughness, comer-rounding, and imperfect angular intersections characteristic of structures formed by nanofabrication techniques. Further, where consideredappropriate, reference labels have been repeated among figures to indicate corresponding or analogous elements.

[0004] Fig. 1 illustrates a process flowchart summarizing operations of an exemplary method of carrying out an in-situ end effector clean cycle, in accordance with at least one implementation.

[0005] Figs. 2A -2E illustrate a series of process steps within a process tool 200, shown in cross-section, for performing an end effector clean operation, in accordance with at least some implementations.

[0006] Fig. 3 illustrates a processor system with a machine-readable storage medium having machine-readable instructions that when executed cause a microcontroller in a circuit board of a control unit for the controller shown in Fig. 2A to execute machine-readable instructions according to the method described in Fig. 1, in accordance with at least one implementation.DETAILED DESCRIPTION

[0007] One or more methods and apparatuses are described to perform in-situ cleaning of an end effector. In at least one implementation, an end effector is inserted into a process chamber configured for CVD or PECVD processes, and the end effector is periodically subject to an oxygen plasma clean cycle that removes accumulated carbonaceous material. In at least one implementation, the end effector plasma clean may be performed automatically between wafer processing operations at predetermined intervals or may be automatically performed after a designated number of wafers have been processed (e.g., a designated number of wafers have undergone a film deposition process by plasma-enhance chemical vapor deposition, PECVD, for example). In at least one implementation, the end effector clean operation may be initiated after visual inspection of the cleanliness state of the end effector. For example, an operator may manually trigger a clean operation when the end effector is deemed to require one.

[0008] Fig, 1 illustrates a process flowchart 100 summarizing operations of an exemplary method of carrying out an in-situ end effector clean cycle, in accordance with at least one implementation. In the following method description, references will be made to apparatus components shown in Figs. 2A-2D. It will be understood that all method steps described herein may be encoded into software, for example, encoded into system software for operation of a process tool (e.g., process tool 200, Fig. 2A) and controlled by a processor, such as a CPU or an embedded microprocessor. Processor (e.g., CPU or embeddedmicroprocessor) operations are described below. A processor may be part of a controller (e.g. controller 212, Fig. 2A) in electronic communication with the process tool. In at least one implementation, the process module (PM) is a vacuum process chamber employed in semiconductor manufacturing that is configured (and may be specialized) to initiate and maintain capacitively-coupled (CCP) or inductively coupled plasmas (ICP) for plasma- assisted processes, such as plasma-assisted deposition processes. For example, the process module may be configured to enable one or more PECVD processes. In at least one implementation, a process module (PM) may be configured for remote plasma clean (RPC) operations, whereby a separate dedicated plasma chamber is attached to the PM, providing a separate plasma source enabling in-situ plasma clean (RPC) operations of components inside the PM rather than direct plasma cleaning by an oxygen plasma. An RPC may be gentler on internal components within the PM than a direct plasma clean using the deposition CCP or ICP apparatus, as ion bombardment (e.g., sputtering) of chamber surfaces for example, by Ar+ ions or other ions, is avoided by an RPC. Sputter erosion of chamber surfaces may thus be mitigated.

[0009] At operation 102, a robot arm and associated end effector (e.g., robot arm 208 and end effector 210 in Fig. 2A) are contained within a vacuum transfer module (e.g., VTM 202). A vacuum transfer module such as VTM 202 may be configured to transfer wafers from a load lock into a process chamber (e.g., process module (PM) 204). In at least one implementation, a load lock is a small vacuum chamber that opens to the atmosphere and is periodically vented to enable loading of unprocessed wafers (usually in a basket of 25 or more wafers) into a main process chamber (e.g., PM 204) that is normally maintained under a high vacuum and not vented to the atmosphere except for occasional maintenance and cleaning.

[0010] Wafers may be positioned within the load lock to enable access by an end effector (e.g., end effector 210 in Fig. 2A) carried by a robot arm (e.g., robot arm 208 in Fig. 2A) and extended into the load lock by the robot arm. The end effector may slide into a gap between wafers stacked vertically in a specialized basket or carrier, lift, and carry one wafer at a time from the load lock, through the vacuum transfer module (VTM) and into the process module (PM). In at least one implementation, the robot arm may comprise two or more articulating segments that may be configured to articulate 360 degrees around rotatable joints. The rotatable joints may be driven by a series of stepper motors. In at least one implementation, articulating segments may be extensible by linear actuators. The combination of two or more extensible articulating segments enables the robot arm to be stowed compactly within theVTM. In at least one implementation, the large degree of articulation and extensibility of the robot arm may enable a large range of movement capability, enabling a long reach into the PM, for example.

[0011] In at least one implementation, a slit valve or movable partition may be present between the VTM and PM. The slit valve or partition may be opened and closed to allow the robot arm and end effector to extend into the PM for wafer transfer. In the closed position, the PM and VTM are isolated from one another, allowing the VTM to be isolated from processes carried out in the PM. A slit valve (e.g., slit valve 206, Fig. 2A) or partition may also be present between a load lock and the VTM, enabling isolation of the VTM from the load lock when the load lock is vented to the atmosphere, for example.

[0012] In at least one implementation, a VTM may be adjoined to multiple PMs. For example, a VTM may have access to three or four PMs, whereby a single robot arm may transfer wafers between the PMs. The multiple PMs may conduct different plasma operations on a single wafer. In at least one implementation, a VTM may be adjoined to a single PM, within which multiple process workstations may be present. For example, a quad chamber may be a PM that has four process stations within. In at least one implementation, a PM may have two process workstations. The process workstations may be configured for plasma processing or for conventional deposition processes. A spindle or indexer may be positioned at the center of the PM between the two or four process stations. The spindle may have a second robot arm and end effector attached to the end of the robot arm, enabling transfer of wafers between process workstations within a single PM. In at least one implementation, up to four wafers may be processed at a time in succession or simultaneously. In at least one implementation, the robot arm contained within the VTM may transfer processed wafers out of the PM and back into the load lock.

[0013] The VTM robot arm and end effector may pick up particles of material that had been deposited on the wafer. For example, small particles of deposition material may fall on the end effector from chamber surfaces within the PM. In addition, small particles may transfer to the end effector from the wafer backside, where some adventitious film deposition may be present. Moreover, incomplete evacuation of process gases may be present in the low-pressure atmosphere of a PM shortly after a deposition process is complete, permitting a small concentration of gas-phase film precursor molecules to be present inside the PM. These precursor molecules may coat the end effector and allow a buildup of film material over time. The material may be carbonaceous.

[0014] Referring again to operation 102 (see Fig. 1), an in-situ end effector cleaning process may be initiated. After all wafer processes are complete, and any wafers may be removed from the PM, the robot arm may be commanded (e.g., by system software) to move the end effector into the PM. In at least one implementation, the robot arm and end effector are stowed in the VTM. A slit valve operating between the VTM and the PM is opened, enabling access to the PM by the robot arm. Under software control or by human command (e.g., using a pendant) the robot arm is commanded to move into the PM, taking the end effector into the PM.

[0015] At operations 104, a nitrogen purge cycle may be initiated to purge the PM of any residual process gases and suspended debris from the previous deposition process. At operations 106 and 108, the robot arm may move the end effector between a pedestal (e.g., pedestal 216, Fig. 2A) and gas distribution plate (e.g., GDP 214 in Fig. 2A) (e.g., GDP is a showerhead) within the PM, where the GDP is located over the pedestal. In many CCP plasma operations, the GDP (showerhead) and pedestal serve as radio-frequency (RF) and direct current (DC) plasma electrodes. In at least one implementation, the robot arm may be commanded to center the end effector over the pedestal to position the end effector within a plasma that may be struck between the GDP and the pedestal. In at least one implementation, a CCP plasma may not be initiated, but rather a remote plasma may be started within an remote clean plasma (RPC) chamber (e.g., RPC chamber 230, Fig. 2E) in communication with the PM. In at least one implementation, RPC chamber may be attached to the PM, whereby the RPC chamber is configured to generate a CCP or ICP plasma. In at least one implementation, a process gas comprising NF3 and / or oxygen gas may be supplied to the RPC chamber. For example, the plasma may dissociate the NF3 molecules to supply oxygen or fluorine atoms (radicals) and nitrogen atoms (radicals) to flow into the PM. The fluorine radicals may consume any carbonaceous materials deposited on chamber surfaces, including the end effector. Similarly, oxygen radicals may also be generated in the RPC chamber and flowed into the PM.

[0016] At operation 110, a purge gas may be introduced into the PM. The purge gas may be nitrogen (N2) gas, for example. The N2 flow may purge the PM of process gases containing remaining PECVD precursor molecules in the vacuum atmosphere within the PM. A process gas flow may be initiated into the PM between the GDP and the pedestal, where the process gas flows from the GDP. The process gas may contain any of oxygen, nitrogen, or fluorine compounds. For example, the process gas may contain oxygen O2, nitrogen N2,and / or F2 or NF3. Inert gases such as argon may also be present. Process gases may flow at rates of several thousand standard cubic centimeters per minute.

[0017] At operations 112, 114 and 116, a plasma may be initiated. In at least one implementation, a CCP plasma may be initiated by directing sufficient RF power into the PM via the GDP and the pedestal. The plasma may be supplied by process gases flowing through the GDP (e.g., the showerhead). In at least one implementation, the plasma process gases may comprise oxygen and / or gases containing NF3 or other suitable reactive gases. The CCP plasma forms between the GDP and the pedestal., which serve as CCP plasma electrodes. From operation 106, the end effector may be positioned between the two CCP plasma electrodes. The CCP plasma may serve as a direct cleaning plasma. In addition to oxygen, nitrogen, or fluorine radicals, an inert gas such as argon and / or nitrogen may be included in the process gas mix. Argon or oxygen ions may also be generated, which may be accelerated toward the end effector by DC bias voltages imposed on the pedestal. The ions may also sputter bombard the end effector, effecting further cleaning but may also cause some erosion of the end effector.

[0018] In at least one implementation, an RPC plasma may be employed instead of a CCP plasma. The indirect plasma created in the RPC chamber creates oxygen or fluorine radicals, as described above, which may flow into the PM via an opening between the two chambers. Ion generation may be confined within the RPC chamber. Radicals generated in the RPC plasma may perform an effective cleaning operation on the end effector without sputtering by accelerated ions.

[0019] In at least one implementation, the in-situ plasma clean process operation may be performed by exposing the end effector to the plasma for at least 10 seconds. For example, the in-situ plasma clean process may be performed by exposing the end effector to the plasma for up to 300 seconds. The plasma power levels and process gas flow rates may be adjusted to obtain the most efficient process. Process gases may flow into the PM at several hundred standard cubic centimeters per minute.

[0020] At operations 118 and 120, the plasma may be extinguished after a period deemed adequate for cleaning the end effector. At operation 118, the end effector may be retracted into the VTM and the slit valve closed. A nitrogen purge may be initiated at operation 120, where the PM may be purged of residual process gases. At operation 122, the slit valve may be closed and at operation 124 the PM may be returned to idle conditions. For example, the base pressure of the chamber may be re-established at operation 124.

[0021] In at least one implementation, a controller may command all the operations by execution of plurality of software instructions that are configured to operate the robot arm, and to command the plasma apparatus associated with the process tool. The software instructions may be called by higher-level routines within a supervisory software system operating the process tool at a system level. In at least one implementation, a supervising software, for example a system software, may autonomously initiate in-situ end effector clean operations on a periodic basis. In at least one implementation, a human operator may initiate an in-situ end effector plasma clean operation. For example, the human operator may control the process tool using a pendant control module. The operator may decide at which point the end effector may require a plasma clean.

[0022] Figs. 2A-2E illustrate a series of process steps within a process tool 200, shown in cross-section, for performing an end effector clean operation, in accordance with at least one implementation. Referring now to Fig. 2A, in at least one implementation, process tool 200 is shown, comprising a vacuum transfer module (VTM) 202 and a process module. (PM) 204. In at least one implementation, VTM 202 and PM 204 are in communication mechanically. In at least one implementation, a slit valve 206 is positioned between VTM 202 and PM 204 to isolate both chambers from one another. During operation, slit valve 206 is opened to allow a robot arm 208 to extend end effector 210 into PM 204. Robot arm 208 and end effector 210 are shown in a stowed position within VTM 202. During wafer processing operations taking place in PM 204, robot arm 208 and end effector 210 are contained within VTM 202 in a stowed position, such as that shown. Slit valve 206 may generally be closed during wafer processing. Although not shown, VTM 202 is also in communication with a load lock for transfer of wafers into and out of process tool 200. Robot arm 208 may be configured to extend end effector 210 into the load lock to bring wafers into and out of process tool 200. A similar slit valve may be present between VTM 202 and a load lock.

[0023] In at least one implementation, a controller 212 may be in electronic communication with robot arm 208. Controller 212 may comprise a processor (not shown), such as a central processing unit (CPU) and / or an embedded microcontroller (e.g., a microprocessor). The processor may be coupled to a memory, which stores or mediates software containing motor command instructions to operate robot arm 208.

[0024] In at least one implementation, a gas distribution plate (GDP) 214 is positioned above a pedestal 216 within PM 204. GDP 214 is configured to distribute process gases over pedestal 216 during deposition operations. Deposition operations may include plasma- assisted deposition processes, such as PECVD, or non-assisted chemical vapor depositionprocesses (e.g., CVD). In at least one implementation, GDP 214 is a showerhead. In at least one implementation, pedestal 216 comprises a platen 218. In at least one implementation, platen 218 may comprise plasma electrodes embedded under the top surface. In at least one implementation, platen 218 is configured to support wafers that are placed upon it by robot arm 208 and end effector 210.

[0025] In at least one implementation, GDP 214 is separated from platen 218 by a gap of several centimeters. A CCP plasma may be ignited and sustained within the gap by imposition of large RF voltages (e.g., several hundred volts rms at 13 MHz) on platen 218 or GDP 214 while process gases flow through GDP 214 to supply precursors and inert gases to the plasma. Both platen 218 and GDP 214 may serve as plasma electrodes in this sense. Inert gases may be ionized and precursors may be dissociated in the RF field. Although plasma- assisted deposition processes such as PECVD are emphasized in this disclosure, it is understood that non-plasma assisted deposition processes such as CVD may also be included.

[0026] Referring again to Fig. 2A, an in-situ end effector plasma clean operation sequence has been initiated. PM 204 may be prepared by initiation of flow of process gases into GDP 214, as indicated by the downward pointing arrows. Vacuum regulation within PM 204 may be performed by control of foreline valve 220 in foreline 222. In at least one implementation, foreline 222 is coupled to a vacuum pumping system, not shown. Opening and closure of foreline valve 220 helps to regulate the pressure within PM 204. During this start-up period, a plasma may be ignited within PM 204 by injection of RF power into PM 204, as described above. Slit valve 206 nay remain closed during the start-up period.

[0027] Referring now to Fig. 2B, slit valve 206 is opened, allowing robot arm 208 to extend end effector 210 into PM 204. Robot arm 208 may be operated autonomously through controller 212 or by a human operator (e.g., with a pendant manual control unit). For example, an operator may control motion of robot arm 208 motion by operating a pendant control unit. In at least one implementation, robot arm 208 is commanded autonomously through system software. Software instructions may be executed by a processor within controller 212 to command drive motors on robot arm 208 to extend and position end effector over pedestal 216. At this point, a CCP plasma 224 may be ignited by injection of RF power into PM 204, specifically by application of large RF voltages on GDP 214 and platen 218.

[0028] Build-up layer 211 on end effector 210 may react with oxygen, fluorine, or other suitable radicals within CCP plasma 224, forming gas-phase molecules that may enter into the atmosphere within PM 204. The gaseous products formed in CCP plasma 224 may be swept out of PM 204 through foreline 222. For example, build-up layer 211 may have a largecarbonaceous content. Such materials may react with oxygen radicals to form mixtures of CO and CO2. In addition, other larger molecule byproducts may be also formed, such as, for instance, reduced forms of CO and CO2 (if hydrogen is present in build-up layer 211; hydrogen may also be present in the plasma gases), such as formaldehyde and other volatile aldehydes, acetone and other volatile ketones, and small carboxylic acids such as formic acid. Such byproducts may be swept out of PM 204 through foreline 222 to the pumping system.

[0029] In at least one implementation, build-up layer 211 may eventually be removed by an RPC clean, whereby plasma radicals generated by a remote plasma within a separate RPC chamber attached to PM 204 may flow into PM 204 through GDP 214 and spread over end effector 210. Such an arrangement is shown in Fig. 2E. For example, oxygen or fluorine radicals may be generated in an RPC chamber and flowed into PM 204.

[0030] Referring now to Fig. 2C, build-up layer 211 is substantially removed from the surfaces of end effector 210 by the in-situ plasma clean operation. CCP plasma 224 may still be active for a short period of time to ensure that end effector 210 is completely clean. In at least one implementation, CCP plasma 224 is extinguished and process gas flow through GDP 214 is stopped.

[0031] Referring now to Fig. 2D, end effector 210 is retracted back into VTM 202 by autonomous command or by human-supervised command through controller 212, as described above. In at least one implementation, a nitrogen purge may be passed through PM 204 to sweep remaining process gases and gaseous byproducts of the in-situ plasma clean of the end effector out of PM 204 (and out of VTM 202). After the N2 purge and any other gas purging, slit valve 206 may be closed to isolate VTM 202 from PM 204. PM 204 may be pumped down to base pressure.

[0032] Fig. 2E illustrates a cross-sectional view of process tool 200, comprising an RPC chamber 230, in accordance with at least one implementation. In at least one implementation, RPC chamber 230 is configured to generate a remote plasma by CCP or ICP techniques. The remote plasma 232 generated within RPC chamber 230 may be flowed through GDP 214 and released into PM 204 over end effector 210 via GDP 214.

[0033] Fig. 3 illustrates a processor system 300 with a machine-readable storage medium having machine-readable instructions that when executed cause a circuit board of a control unit of processor and memory of a computing system, for example as shown in Fig. 2A, to execute machine-readable instructions according to the method summarized by flowchart 100, shown in Fig. 1, for example.

[0034] In at least one implementation, a microcontroller may be configured to execute a plurality of software instructions to operate a robot arm (e.g., robot arm 208) and control a plasma apparatus associated with a process tool (e.g., process tool 200). In at least one implementation, processes described herein may be stored in a machine readable medium, (e.g., 303) as computer-executable instructions. In at least one implementation, a machine- readable storage medium may be random access memory (RAM). In at least one implementation, processor system 300 comprises a memory 301, a processor 302, machine- readable storage medium 303 (also referred to as tangible machine-readable medium), a communication interface 304 (e.g., a wireless or a wired interface), and a network bus 305 coupled together as shown. In at least one implementation, processor system 300 may be part of computing system represented by controller 212 shown in Fig. 2A (containing a processor and a memory, for example).

[0035] In at least one implementation, processor 302 is a digital signal processor (DSP), an application specific integrated circuit (ASIC), a general -purpose central processing unit (CPU), or a low power logic implementing a simple finite state machine to perform various processes described herein.

[0036] In at least one implementation, various logic blocks of processor system 300 are coupled together via network bus 305. Any suitable protocol may be used to implement network bus 305. In at least one implementation, machine-readable storage medium 303 includes instructions (also referred to as program software code / instructions) to raise and lower a thermochromic film coded into software stored in machine-readable storage medium 303.

[0037] In at least one implementation, machine-readable storage media 303 is a machine- readable storage media with instructions for positioning an end effector, such as end effector 210 by commanding one or more drive motors on robot arm 208. In at least one implementation, machine-readable medium 303 has machine-readable instructions, that when executed, cause processor 302 to perform the method discussed herein (e.g., see flowchart 100 in Fig. 1).

[0038] In at least one implementation, program software code / instructions associated with various implementations may be implemented as part of an operating system or a specific application, component, program, object, module, routine, or other sequence of instructions or organization of sequences of instructions referred to as "program software code / instructions," "operating system program software code / instructions," "application program software code / instructions," or simply "software" or firmware embedded inprocessor. In some implementations, program software code / instructions associated with processes of various implementations are executed by processor system 300.

[0039] In at least one implementation, machine-readable storage media 303 is a computer executable storage medium. In at least one implementation, program software code / instructions associated with various implementations are stored in computer executable storage medium 303 and executed by processor 302. Here, computer executable storage medium 303 is a tangible machine-readable medium 303 that can be used to store program software code / instructions and data that, when executed by a computing device, causes one or more processors (e.g., processor 302) to perform a process.

[0040] In at least one implementation, tangible machine-readable medium 303 may include storage of executable software program code / instructions and data in various tangible locations, including for example, ROM, volatile RAM, non-volatile memory, and / or cache, and / or other tangible memory as referenced in present application. Portions of this program software code / instructions and / or data may be stored in any one of these storage and memory devices. In some implementations, program software code / instructions can be obtained from other storage, including, e.g., through centralized servers or peer to peer networks and like, including Internet. Different portions of software program code / instructions and data can be obtained at different times and in different communication sessions or in same communication session.

[0041] In at least one implementation, software program code / instructions associated with various implementations can be obtained in their entirety prior to execution of a respective software program or application. Alternatively, portions of software program code / instructions and data can be obtained dynamically, e.g., just in time, when needed for execution. Alternatively, some combination of these ways of obtaining software program code / instructions and data may occur, e.g., for different applications, components, programs, objects, modules, routines, or other sequences of instructions or organization of sequences of instructions, by way of example. Thus, it is not required that data and instructions be on a tangible machine-readable medium 303 in entirety at a particular instance of time.

[0042] In at least one implementation, tangible machine-readable medium 303 include but are not limited to recordable and non-recordable type media such as volatile and nonvolatile memory devices, read only memory (ROM), random access memory (RAM), flash memory devices, floppy and other removable disks, magnetic storage media, optical storage media (e.g., Compact Disk Read-Only Memory (CD ROMs), Digital Versatile Disks (DVDs), etc.), among others. In at least one implementation, software programcode / instructions may be temporarily stored in digital tangible communication links while implementing electrical, optical, acoustical, or other forms of propagating signals, such as carrier waves, infrared signals, digital signals, etc. through such tangible communication links.

[0043] In some instances, well-known methods and devices are shown in block diagram form, rather than in detail, to avoid obscuring at least one implementation. Reference throughout this specification to “an implementation,” “one implementation,” “in at least one implementation,” or “some implementations” means that a particular feature, structure, function, or characteristic described in connection with implementation is included in at least one implementation. Thus, appearances of phrase “in an implementation,” “in at least one implementation,” or “in one implementation” or “some implementations” in various places throughout this specification are not necessarily referring to same implementation of disclosure. Furthermore, particular features, structures, functions, or characteristics may be combined in any suitable manner in one or more implementations. For example, a first implementation may be combined with a second implementation anywhere particular features, structures, functions, or characteristics associated with two implementations are not mutually exclusive.

[0044] As used in herein, singular forms “a”, “an,” and “the” are intended to include plural forms as well, unless context clearly indicates otherwise. It will also be understood that term “and / or” as used herein refers to and encompasses all possible combinations of one or more of associated listed items.

[0045] Here, “coupled” and “connected,” along with their derivatives, may be used herein to describe functional or structural relationships between components. These terms are not intended as synonyms for each other. Rather, in particular implementations, “connected” may be used to indicate that two or more elements are in direct physical, optical, or electrical contact with each other. “Coupled” may be used to indicated that two or more elements are in either direct or indirect (with other intervening elements between them) physical, electrical or in magnetic contact with each other, and / or that two or more elements co-operate or interact with each other (e.g., as in a cause an effect relationship).

[0046] Here, “over,” “under,” “between,” and “on” as used herein refer to a relative position of one component or material with respect to other components or materials where such physical relationships are noteworthy. For example, in context of materials, one material or material disposed over or under another may be directly in contact or may have one or more intervening materials. Moreover, one material disposed between two materials may bedirectly in contact with two layers or may have one or more intervening layers. In contrast, a first material “on” a second material is in direct contact with that second material / material. Similar distinctions are to be made in context of component assemblies. As used throughout this description, and in claims, a list of items joined by term “at least one of’ or “one or more of’ can mean any combination of listed terms.

[0047] Here, “adjacent” generally refers to a position of a thing being next to (e.g., immediately next to or close to with one or more things between them) or adjoining another thing (e.g., abutting it).

[0048] Here, “centered” may generally refer to positioning a device or object substantially at a midway distance between two or more reference objects.

[0049] Here, “process tool” may generally refer to a semiconductor manufacturing tool comprising one or more vacuum chambers. The vacuum chambers are configured to carry out one or more semiconductor device fabrication processes, including film deposition processes on semiconductor wafers. Film deposition may include plasma-assisted processes, such as plasma-assisted chemical vapor deposition (PECVD).

[0050] Here, “process module” (PM) may generally refer to a vacuum chamber configured to carry out the semiconductor device fabrication processes described in the preceding paragraph. The PM is part of the process tool.

[0051] Here, “vacuum transfer module” (VTM) may generally refer to a pre-chamber attached to the process module. The VTM is part of the process tool and may house a robot arm for transferring wafers into and out of the process module. A load lock may be attached to the VTM for bring wafers into and out of the process tool.

[0052] Here, “controller” may generally refer to an electronic device comprising a processor, such as a central processing unit (CPU), and / or a microprocessor. A memory may also be included in the controller. A controller may be in communication with various components of the process tool, as described herein.

[0053] Here, “software instructions” may generally refer to software code lines executed by a processor within the controller.

[0054] Here, “robot arm” may generally refer to an articulating arm that is controlled by a processor or controller. The robot arm may comprise one or more drive motors to actuate the robot arm, that is, to control articulating sections of the robot arm and extension of those sections, so that movements of the robot arm may resemble movements of a human arm. The robot arm may have an end effector attached to the distal end of the robot arm.

[0055] Here, “end effector” may generally refer to the “hand” of the robot arm. An end effector is generally a flat, fork-shaped device having two or more prongs for picking up and manipulating wafers during transfer within a PM or between a VTM and a PM.

[0056] Here, “gas distribution plate” (GDP) may generally refer to a showerhead gas distribution device for distribution of process gases into a process module. A showerhead has a faceplate, for example, and the GDP may be the faceplate of the showerhead.

[0057] Here, “pedestal” may generally refer to a support stand within a PM for semiconductor wafers undergoing processing.

[0058] Here, “plasma” may generally refer to a fourth state of matter, comprising charged particles (ions), free electrons and atomic or molecular radicals.

[0059] Here, “remote plasma” may generally refer to a plasma generated in a remote plasma chamber, for example, as described herein. The remote plasma chamber is generally attached to the PM, and configured to generate a remote plasma, which is flowed into the PM for general chamber cleaning operations.

[0060] Here, “device” may generally refer to an apparatus according to context of usage of that term. For example, a device may refer to a stack of layers or structures, a single structure or layer, a connection of various structures having active and / or passive elements, etc. Generally, a device is a three-dimensional structure with a plane along x-y direction and a height along z direction of an x-y-z Cartesian coordinate system. In at least one implementation, plane of device may also be plane of an apparatus which comprises device.

[0061] Unless otherwise specified in explicit context of their use, terms “substantially equal,” “about equal,” and “approximately equal” mean that there is no more than incidental variation between two things so described. Such variation is typically no more than + / - 10% of a predetermined target value.

[0062] Here, “left,” “right,” “front,” “back,” “top,” “bottom,” “over,” “under,” and similar terms are used for descriptive purposes and not necessarily for describing permanent relative positions. For example, terms “over,” “under,” “front side,” “back side,” “top,” “bottom,” “over,” “under,” and “on” as used herein refer to a relative position of one component, structure, or material with respect to other referenced components, structures, or materials within a device, where such physical relationships are noteworthy. These terms are employed herein for descriptive purposes only and predominantly within context of a device z-axis and therefore may be relative to an orientation of a device. Hence, a first material “over” a second material in context of a figure provided herein may also be “under” secondmaterial if device is oriented upside-down relative to context of figure provided. Similar distinctions are to be made in context of component assemblies.

[0063] Here, a device that is “configured to” perform a task or function may be configured (e.g., programmed and / or hardwired) at a time of manufacturing by a manufacturer to perform the function. In at least one example, the device may be configurable (or reconfigurable) by a user after manufacturing to perform the function and / or other additional or alternative functions. In at least one example, the configuring may be through firmware and / or software programming of the device, through a construction and / or layout of hardware components and interconnections of the device, or a combination thereof.

[0064] Here, “between” may be employed in context of z-axis, x-axis or y-axis of a device. A material that is between two other materials may be in contact with one or both of those materials. In another example, a material that is between two or other material may be separated from both of other two materials by one or more intervening materials. A material “between” two other materials may therefore be in contact with either of other two materials. In another example, a material “between” two other materials may be coupled to other two materials through an intervening material. A device that is between two other devices may be directly connected to one or both of those devices. In another example, a device that is between two other devices may be separated from both of other two devices by one or more intervening devices.

[0065] The structures of various examples described herein can also be described as method(s) of forming those structures or apparatuses, and method(s) of operation of these structures or apparatuses. The following examples are provided that illustrate the various examples of the disclosure. The examples can be combined with other examples. As such, various examples can be combined with other examples without changing the scope of the invention.

[0066] Example l is a method for performing an in-situ plasma cleaning of an end effector, comprising: moving the end effector into a process module from a vacuum transfer module attached to the process module; positioning the end effector below a gas distribution plate; flowing a plasma over the gas distribution plate; exposing the end effector to the plasma; and retracting the end effector into the vacuum transfer module.

[0067] Example 2 is method as in any of the examples, particularly example 1, wherein moving the end effector into the process module from the vacuum transfer module comprises commanding a robot arm attached to the end effector.

[0068] Example 3 is a method as in any of the examples, particularly example 2, wherein commanding the robot arm attached to the end effector comprises executing a plurality of software instructions by a processor coupled to the robot arm., wherein the plurality of software instructions is configured to command one or more drive motors on the robot arm.

[0069] Example 4 is a method as in any of the examples, particularly example 3, wherein executing the plurality of software instructions by the processor comprises autonomously initiating execution of the plurality of software instructions by a supervisory software system.

[0070] Example 5 is a method as in any of the examples, particularly example 3, wherein executing the plurality of software instructions by the processor comprises manually initiating execution of the plurality of software instructions by a human operator.

[0071] Example 6 is as method as in any of the examples, particularly example 1, wherein igniting a plasma between the gas distribution plate and the pedestal comprises flowing a process gas through the gas distribution plate.

[0072] Example 7 is a method as in any of the examples, particularly example 6, wherein igniting a plasma between the gas distribution plate and the pedestal comprises flowing a process gas through the gas distribution plate.

[0073] Example 8 is a method as in any of the examples, particularly example 7, wherein the process gas comprises oxygen, nitrogen and fluorine compounds.

[0074] Example 9 is a method as in any of the examples, particularly example 6, wherein flow the plasma over the gas distribution plate comprises flowing a remote plasma generated in a remote plasma clean (RPC) chamber attached to the process module, and wherein the remote plasma is flowed into the process module.

[0075] Example 10 is a method as in any of the examples, particularly example 9, wherein flowing the remote plasma into the process module comprises flowing the remote plasma through the gas distribution plate.

[0076] Example 11 is a method as in any of the examples, particularly example 1, wherein exposing the end effector to the plasma comprises exposing the end effector to the plasma for a period of at least 10 seconds.

[0077] Example 12 is a method as in any of the examples, particularly example 1, wherein retracting the end effector into the vacuum transfer module comprises commanding a robot arm attached to the end effector.

[0078] Example 13 is a method as in any of the examples, particularly example 12, wherein commanding the robot arm attached to the end effector comprises executing aplurality of software instructions by a controller coupled to the robot arm., wherein the plurality of software instructions command one or more drive motors on the robot arm.

[0079] Example 14 is a method as in any of the examples, particularly example 13, wherein executing the plurality of software instructions by the controller comprises autonomously initiating execution of the plurality of software instructions by a supervisory software system.

[0080] Example 15 is a method as in any of the examples, particularly example 13, wherein executing the plurality of software instructions by the controller comprises manually initiating execution of the plurality of software instructions by a human operator.

[0081] Example 16 is a method as in any of the examples, particularly example 1, further comprising purging the process module with a flow of nitrogen gas.

[0082] Example 17 is a process tool configured to perform an in-situ plasma cleaning operation of an end effector comprising a vacuum transfer module; a process module attached to the vacuum transfer module; a robot arm within the vacuum transfer module, wherein the end effector is attached to the robot arm; and a controller electronically coupled to the robot arm, wherein the controller is configured to execute a plurality of software instructions to perform the in-situ plasma cleaning operation.

[0083] Example 18 is a process tool as in any of the examples, particularly example 17, wherein the plurality of software instructions is configured to command a plurality of movements of the robot arm between the vacuum transfer module and the process module, and to initiate a plasma within the process module.

[0084] Example 19 is a process tool as in any of the examples, particularly example 17, wherein a remote plasma chamber is attached to the process module.

[0085] Example 20 is a process tool as in any of the examples, particularly example 19, wherein a gas distribution plate is within the process module, and wherein the gas distribution plate is configured to flow a remote plasma from the remote plasma chamber to the process module.

Claims

CLAIMSWhat is claimed is:

1. A method for performing an in-situ plasma cleaning of an end effector, comprising: moving the end effector into a process module from a vacuum transfer module attached to the process module; positioning the end effector below a gas distribution plate; flowing a plasma over the gas distribution plate; exposing the end effector to the plasma; and retracting the end effector into the vacuum transfer module.

2. The method of claim 1, wherein moving the end effector into the process module from the vacuum transfer module comprises commanding a robot arm attached to the end effector.

3. The method of claim 2, wherein commanding the robot arm attached to the end effector comprises executing a plurality of software instructions by a processor coupled to the robot arm, wherein the plurality of software instructions is configured to command one or more drive motors on the robot arm.

4. The method of claim 3, wherein executing the plurality of software instructions by the processor comprises autonomously initiating execution of the plurality of software instructions by a supervisory software system.

5. The method of claim 3, wherein executing the plurality of software instructions by the processor comprises manually initiating execution of the plurality of software instructions by a human operator.

6. The method of claim 1, wherein flowing the plasma over the gas distribution plate comprises igniting the plasma between the gas distribution plate and a pedestal.

7. The method of claim 6, wherein igniting the plasma between the gas distribution plate and the pedestal comprises flowing a process gas through the gas distribution plate.

8. The method of claim 7, wherein the process gas comprises oxygen, nitrogen, or fluorine compounds.

9. The method of claim 6, wherein flow the plasma over the gas distribution plate comprises flowing a remote plasma generated in a remote plasma clean (RPC) chamber attached to the process module, and wherein the remote plasma is flowed into the process module.

10. The method of claim 9, wherein flowing the remote plasma into the process module comprises flowing the remote plasma through the gas distribution plate.

11. The method of claim 1, wherein exposing the end effector to the plasma comprises exposing the end effector to the plasma for a period of at least 10 seconds.

12. The method of claim 1, wherein retracting the end effector into the vacuum transfer module comprises commanding a robot arm attached to the end effector.

13. The method of claim 12, wherein commanding the robot arm attached to the end effector comprises executing a plurality of software instructions by a controller coupled to the robot arm, wherein the plurality of software instructions command one or more drive motors on the robot arm.

14. The method of claim 13, wherein executing the plurality of software instructions by the controller comprises autonomously initiating execution of the plurality of software instructions by a supervisory software system.

15. The method of claim 13, wherein executing the plurality of software instructions by the controller comprises manually initiating execution of the plurality of software instructions by a human operator.

16. The method of claim 1, further comprising purging the process module with a flow of nitrogen gas.

17. A process tool configured to perform an in-situ plasma cleaning operation of an end effector, comprising: a vacuum transfer module; a process module attached to the vacuum transfer module; a robot arm within the vacuum transfer module, wherein the end effector is attached to the robot arm; and a controller electronically coupled to the robot arm, wherein the controller is to execute a plurality of software instructions to perform the in-situ plasma cleaning operation.

18. The process tool of claim 17, wherein the plurality of software instructions is configured to command a plurality of movements of the robot arm between the vacuum transfer module and the process module, and to initiate a plasma within the process module.

19. The process tool of claim 17, wherein a remote plasma chamber is attached to the process module.

20. The process tool of claim 19, wherein a gas distribution plate is within the process module, and wherein the gas distribution plate is configured to flow a remote plasma from the remote plasma chamber to the process module.

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