Remote plasma cleaning of chambers for electronic manufacturing systems

Abstract

To provide methods and systems for cleaning chambers and components of an electronics manufacturing system for removing a plurality of organic contaminants from the chambers.SOLUTION: A method of cleaning a plurality of chambers that are subject to vacuum during operation for an electronics manufacturing system includes flowing a gas mixture comprising oxygen and carrier gas into a remote plasma generator, generating plasma from the gas mixture by the remote plasma generator, and performing remote plasma cleaning of a chamber by flowing the plasma into an interior of the chamber, where the plasma removes a plurality of organic contaminants from the chamber.SELECTED DRAWING: Figure 3

Description

[Technical Field]

[0001] TECHNICAL FIELD

[0001] Embodiments of the present disclosure relate generally to methods and systems for cleaning chambers and components of electronic manufacturing systems, and more particularly to remote plasma cleaning of chambers of electronic manufacturing systems. [Background technology]

[0002]

[0002] Electronics manufacturing systems typically include multiple chambers (e.g., transfer chambers, load lock chambers, processing chambers, etc.) that are exposed to a vacuum during operation. During the manufacturing of the chambers, organic contaminants and / or airborne molecular contaminants (AMCs) are introduced into various components of the chambers. Such organic contaminants may be introduced by component handling, component machining, component packaging, sealants, lubricants, and / or various other sources. When the chambers are first used under vacuum in a manufacturing environment, organic contaminants deposit on substrates placed in, processed by, and / or moved through the chambers. Traditionally, chambers are cleaned in manufacturing environments before use by wiping the chambers with isopropyl alcohol (IPA). However, the IPA wipe cleaning technique does not remove all of the organic contaminants or prevent the organic contaminants from depositing on substrates. Summary of the Invention

[0003] Some of the described embodiments cover a method for performing remote plasma cleaning of a chamber for an electronics manufacturing system. One or more components of a chamber for the electronics manufacturing system are machined. A chamber is then assembled using the one or more components, and after assembly, the chamber contains multiple organic contaminants. A gas mixture including oxygen and a carrier gas is flowed into a remote plasma generator connected to the chamber. The remote plasma generator generates a plasma from the gas mixture. The remote plasma cleaning of the chamber is performed by flowing a plasma inside the chamber, and the plasma removes the multiple organic contaminants from the chamber.

[0004]

[0005] The present disclosure is illustrated by way of example, and not limitation, in the figures of the accompanying drawings, in which like reference numerals indicate like elements. It should be noted that different references to "an" or "one" embodiment in the present disclosure are not necessarily to the same embodiment, and such references mean at least one. [Brief explanation of the drawings]

[0005] [Figure 1] 1 is a top schematic view of an exemplary electronics manufacturing system undergoing a remote plasma cleaning process, according to aspects of the present disclosure. [Figure 2] 1 is a top schematic view of an exemplary electronics manufacturing system undergoing a remote plasma cleaning process, according to aspects of the present disclosure. [Figure 3] 1 is a flowchart of a method for performing remote plasma cleaning of one or more chambers of an electronic processing system according to an embodiment of the present disclosure. [Figure 4] 1 is a flowchart of a method for remote plasma cleaning one or more chambers of an electronics manufacturing system prior to shipping of the electronics manufacturing system, according to an embodiment of the present disclosure. [Figure 5] 1 illustrates possible locations in an electronics manufacturing system to which a remote plasma source can be connected to perform remote plasma cleaning of one or more chambers of the electronics manufacturing system. [Figure 6A] 1 illustrates an exemplary remote plasma generator. [Figure 6B] 1 shows an adapter for connecting a remote plasma generator to the chamber. [Figure 7] 1 illustrates the operating principle of carbon removal using a remote plasma cleaning process. [Figure 8] 1 shows test results for remote plasma cleaning according to an embodiment of the present disclosure. [Figure 9] 1 shows test results for remote plasma cleaning according to an embodiment of the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0006]

[0016] Embodiments described herein relate to methods and systems for cleaning chambers in electronics manufacturing systems using a remote plasma cleaning process. Various chambers in electronics manufacturing systems typically contain organic contaminants and / or airborne molecular contaminants (AMCs) after machining and assembly. Organic contaminants include, for example, hydrocarbon-based organic contaminants, aromatic organic contaminants, and / or ester-based organic contaminants. These organic contaminants can be introduced into various components of the chamber through component handling, component machining, and component packaging. Additionally, components may contain sealants, lubricants, and / or other products that result in organic contaminants. When a chamber is first used in a vacuum, organic contaminants deposit on substrates placed in, processed by, and / or moved through the chamber. Conventional techniques for cleaning chambers in electronics manufacturing systems before their first use with product substrates have proven insufficient to adequately remove organic contaminants. Furthermore, conventional techniques for cleaning chambers in electronics processing systems can take days to weeks, which increases the cost of ownership of the electronics manufacturing system.

[0007]

[0017] In an exemplary conventional technique for cleaning an electronics processing system chamber before first use, the chamber undergoes a wet clean, in which the interior of the chamber is wiped with IPA. After such an IPA wipe, testing is often performed to determine the amount of organic contamination on a substrate placed in the chamber under vacuum. If the level of organic contamination exceeds a threshold, testing can be performed to identify the possible source of the organic contamination, and components identified as the possible source of the organic contamination can then be replaced. This process can take a week or more and is often ineffective. Another standard technique for preparing a new electronics processing system for use is to perform a wafer cycle of the electronics processing system chamber while monitoring outgassing with a residual gas analyzer (RGA), which can take weeks to perform, is expensive, and may not effectively reduce organic contamination.

[0008]

[0018] Embodiments describe a remote plasma cleaning process for cleaning one or more chambers of an electronic processing system. A gas mixture including oxygen and a carrier gas is flowed into a remote plasma system (RPS, also referred to herein as a remote plasma generator). The remote plasma system generates a plasma from the gas mixture and delivers the plasma into one or more chambers of the electronic processing system. In one embodiment, the interior of the one or more chambers is heated as the plasma is delivered, causing organic contaminants and / or airborne molecular contaminants (AMC) inside the chamber to begin vaporizing. The remote plasma reacts with the organic contaminants and / or AMC inside the chamber, and the reactants are pumped out of the chamber. The remote plasma cleaning process described in the embodiments has been tested on several different chambers, and the tests show that the process effectively removes all or nearly all of the organic contaminants and / or AMC inside the chamber. Furthermore, the remote plasma cleaning process can be performed in less than half a day, significantly reducing the time required to bring a new electronic processing system online compared to conventional techniques for cleaning and / or otherwise preparing a new electronic manufacturing system for use in a product. For example, the time to qualify a new electronic manufacturing system (or its chamber) can be reduced from days or weeks to less than one day. Additionally, the cost of performing a remote plasma cleaning process is significantly less than the cost of performing a wafer cycle and the cost of replacing chamber components. Thus, the remote plasma cleaning process described in embodiments herein is more efficient and robust than conventional cleaning and qualification techniques for new electronic manufacturing systems.

[0009]

[0019] The remote plasma cleaning process described herein can be performed on any sealed or sealable chamber, offering particular advantages for chambers exposed to vacuum conditions during operation. Examples of such chambers include load lock chambers, transfer chambers, factory interfaces, sealed alignment stations, vias, buffers, purge chambers, and process chambers such as physical vapor deposition (PVD) process chambers, chemical vapor deposition (CVD) process chambers, etch process chambers, and atomic layer deposition (ALD) process chambers. The remote plasma cleaning process may also be performed on other assemblies with sealed internal volumes used in device fabrication to remove organic contaminants and / or AMC. An example of such an assembly with a sealed internal volume is a substrate carrier, such as a front-opening integrated pod (FOUP) or a side storage pod (SSP). Therefore, it should be understood that embodiments discussed herein with respect to performing plasma cleaning of a chamber also apply to performing plasma cleaning of other assemblies with sealed volumes.

[0010]

[0020] 1 is a top-view schematic diagram of an exemplary electronics manufacturing system 100 according to one embodiment of the present disclosure. The electronics manufacturing system 100 is capable of performing one or more processes on a substrate 102. The substrate 102 may be any suitably rigid, fixed-dimensional, planar article suitable for fabricating electronic devices or circuit components thereon, such as, for example, a silicon-containing disk or wafer, a patterned wafer, a glass plate, or the like.

[0011]

[0021] The electronics manufacturing system 100 may include a mainframe 104 and a factory interface 106 coupled to the mainframe 104. The mainframe 104 may include a housing 108 having a transfer chamber 110 therein. The transfer chamber 110 may include one or more processing chambers (also referred to as process chambers) 116a-116f disposed therearound and coupled thereto. The processing chambers 116a-116f may be coupled to the transfer chamber 110 via respective ports 131, which may include slit valves or the like.

[0012]

[0022] Note that the main frame is shown as being generally square-shaped, having four sides (also called facets), with multiple processing chambers connected to each facet. However, it should be understood that a facet can include a single processing chamber or more than two processing chambers coupled thereto. Additionally, the main frame 104 can have other shapes, such as a rectangular shape (different facets can have different lengths) or a radial shape with more than four facets (e.g., five, six, or more facets).

[0013]

[0023] The processing chambers 116a-116f may be adapted to perform any number of processes on the substrate 102. In one embodiment, one or more of the processing chambers 116a-116f are configured to operate under vacuum conditions (e.g., pressures less than 1 ATM, pressures less than 100 mTorr, etc.). The same or different substrate processes may be performed in each processing chamber 116a-116f. The substrate processes may include atomic layer deposition (ALD), physical vapor deposition (PVD), chemical vapor deposition (CVD), etching, annealing, curing, pre-cleaning, metal or metal oxide removal, etc. In one example, a PVD process may be performed in one or both of the process chambers 116a-116b, an etching process may be performed in one or both of the process chambers 116c, 116d, and an annealing process may be performed in one or both of the process chambers 116e, 116f. Other processes may also be performed on substrates therein. The processing chambers 116a-116f may each include a substrate support assembly. The substrate support assembly may be configured to hold a substrate in place while a substrate process is being performed.

[0014]

[0024] The transfer chamber 110 can also include a transfer chamber robot 112. The transfer chamber robot 112 can include one or more robot arms, each including one or more end effectors (also referred to herein as blades) at the end of the robot arm. The end effectors can be configured to handle specific objects, such as wafers. Alternatively, or additionally, the end effectors can be configured to handle objects, such as process kit rings. In some embodiments, the transfer chamber robot 112 can be a Selected Compliance Assembly Robot Arm (SCARA) robot, such as a two-link SCARA robot, a three-link SCARA robot, or a four-link SCARA robot. The transfer chamber 110 of one embodiment is configured to operate under vacuum conditions (e.g., pressures less than 1 ATM, pressures less than 100 mTorr, etc.).

[0015]

[0025] One or more load locks 120a, 120b (also referred to as load lock chambers) may also be coupled to the housing 108 and the transfer chamber 110. The load locks 120a, 120b may be configured to interface with the transfer chamber 110 on one side and with the factory interface 106 on the other side. The load locks 120a, 120b may have an environmentally controlled atmosphere that can be changed from a vacuum environment (where substrates may be transferred to and from the transfer chamber 110) to an atmospheric or near-atmospheric (e.g., with an inert gas) environment (where substrates may be transferred to and from the factory interface 106), in some embodiments.

[0016]

[0026] In some embodiments, ports 131 and / or slit valves are at the interface between the processing chambers 116a-116f and the transfer chamber 110. In embodiments, ports 133 and / or slit valves separate the transfer chamber 110 from the load locks 120a, 120b.

[0017]

[0027] The factory interface (FI) 106 may be any suitable enclosure, such as, for example, an Equipment Front End Module (EFEM). The factory interface 106 may be configured to receive substrates 102 from substrate carriers 122 (e.g., Front Opening Integrated Pods (FOUPs)) docked to various load ports 124 of the factory interface 106. A factory interface robot 126 (shown in dotted lines) may be configured to transfer substrates 102 between the substrate carriers (also called containers) 122 and the load locks 120. The factory interface robot 126 may include one or more robot arms and may be or include a SCARA robot. The factory interface robot 126 may include an end effector at the end of each robot arm. The end effector may be configured to pick up and handle specific objects, such as wafers. Alternatively, or additionally, the end effector may be configured to handle objects, such as process kit rings.

[0018]

[0028] Any conventional robot type can be used for the factory interface robot 126. Transfers can be performed in any order or direction. The factory interface 106, in some embodiments, can be maintained in a non-reactive gas environment (e.g., using nitrogen as the non-reactive gas), for example, at a slight positive pressure.

[0019]

[0029] In some embodiments, a lateral storage pod (SSP, not shown) is coupled to the FI 106.

[0020]

[0030] In some embodiments, the transfer chamber 110, the process chambers 116a-116f, and the load locks 120a-120b may be maintained at a vacuum level. The electronics manufacturing system 100 may include one or more ports 130, 131, 133 (e.g., vacuum ports) coupled to one or more stations of the electronics manufacturing system 100. For example, the port 130 (e.g., vacuum port) may couple the factory interface 106 to the load lock 120. An additional port 133 (e.g., vacuum port) may be coupled to the load lock 120 and disposed between the load lock 120 and the transfer chamber 110, as described above. Each of the ports 130, 133, 131 may include a slit valve that separates the vacuum environment from a higher pressure (e.g., atmospheric) environment.

[0021]

[0031] In some embodiments, the aligner station 128 is coupled to the FI 106. Alternatively, the aligner station 128 may be housed within the FI 106. In some embodiments, a port separates the aligner station 128 from the FI 106. The aligner station 128 is configured to align substrates, fixtures, and / or other objects (e.g., process kit rings) to a target orientation.

[0022]

[0032] The electronics manufacturing system 100 may also include a system controller 132. The system controller 132 can be and / or include a computing device such as a personal computer, a server computer, a programmable logic controller (PLC), a microcontroller, etc. The system controller 132 can include one or more processing devices, which can be general-purpose processing devices such as a microprocessor, a central processing unit, etc. More specifically, the processing device may be a complex instruction set computing (CISC) microprocessor, a reduced instruction set computing (RISC) microprocessor, a very long instruction word (VLIW) microprocessor, or a processor implementing other instruction sets or a processor implementing a combination of instruction sets. The processing device may also be one or more special-purpose processing devices, such as an application-specific integrated circuit (ASIC), a field-programmable gate array (FPGA), a digital signal processor (DSP), a network processor, etc. The system controller 132 can include data storage (e.g., one or more disk drives and / or solid-state drives), main memory, static memory, a network interface, and / or other components. The system controller 132 can execute instructions to perform any one or more of the methods and / or embodiments described herein. The instructions may be stored in a computer-readable storage medium, including a main memory, a static memory, a secondary storage device, and / or a processing device (during execution of the instructions). The system controller 132 may also be configured to allow a human operator to input and display data, operate commands, and the like.

[0023]

[0033] In embodiments, the electronics manufacturing system 100 (or one or more chambers thereof) may be cleaned using a remote plasma cleaning process after assembly of the electronics manufacturing system 100. Alternatively, one or more chambers of the electronics manufacturing system 100 may be assembled and cleaned before the entire electronics assembly is assembled. For example, the transfer chamber 110 may be assembled and then cleaned using a remote plasma cleaning process described herein before any of the process chambers 116a-116c, the load locks 120a-120b, and / or the FI 106 are connected to it. Similarly, any of the process chambers 116a-116c may be cleaned using a remote cleaning process before connection to the transfer chamber 110, and / or the load locks 120a-120b may be cleaned before connection to the transfer chamber 110. In another example, the load locks 120a-120b may be connected to the transfer chamber 110, and the transfer chamber 110 and the load locks 120a-120b may be cleaned together using a remote plasma cleaning process described herein. The remote plasma cleaning process may be performed separately for each of the process chambers 116a-116f, or one or more of the process chambers 116a-116f may be connected to the transfer chamber 110, and the remote plasma cleaning process may be performed to clean the process chambers 116a-116f, the transfer chamber 110, and / or the load locks 120a, 120b together.

[0024]

[0034] To perform a plasma cleaning process, a remote plasma system (RPS, also called a remote plasma generator) 101 is connected to one chamber to be cleaned. The RPS 101 may be connected to the chamber, for example, at a window or port of the chamber. All other windows and / or ports of the chamber may be sealed, and the interior of the chamber is pumped to a vacuum. If the connected chambers are to be cleaned with the same cleaning process, the ports connecting the chamber to other chambers can be opened for the cleaning process. In some embodiments, multiple RPSs 101 are connected to the chamber (or to more than one of the connected chambers), and each of the multiple RPSs delivers a remote plasma into the chamber.

[0025]

[0035] In some embodiments, the interior of the chamber is heated during the remote plasma cleaning process. Such heating can be accomplished, in embodiments, using the chamber's built-in heating elements. Alternatively, a temporary heating system may be inserted into the chamber and used to heat the interior of the chamber. In another embodiment, heating is accomplished by hot gas injection.

[0026]

[0036] In embodiments, the RPS 101 is directly connected to the chamber to be cleaned (e.g., the transfer chamber 110) without any piping separating the RPS 101 from the chamber to which it is connected. This maximizes the efficiency of the cleaning process and minimizes the amount of plasma radical recombination that can occur if the RPS is indirectly connected to the chamber (e.g., through intermediate piping). Alternatively, a minimal amount of piping may separate the RPS 101 from the chamber to which it is connected.

[0027]

[0037] The RPS 101 can be positioned in the chamber to be cleaned to maximize the efficiency of the cleaning. For example, if the transfer chamber 110 and connected load lock chambers 120 a, 120 b are to be cleaned together, the RPS 101 can be connected to a port or window in the transfer chamber 110 that is on or near the side of the transfer chamber opposite the side to which the load lock chambers 120 a, 120 b are connected. This can ensure that the plasma flow direction 109 travels directly (or as nearly as possible) (e.g., in a generally straight line) from the RPS 101 into both the transfer chamber 110 and the load lock chambers 120 a, 120 b.

[0028]

[0038] Certain ranges of gas mixtures, temperatures, process times, and plasma powers may be used in embodiments for the remote plasma cleaning process, as described in more detail below.

[0029]

[0039] FIG. 2 is a schematic top view of an exemplary electronics manufacturing system 200 according to one embodiment of the present disclosure. The electronics manufacturing system 200 can perform one or more processes on a substrate. The electronics manufacturing system 200 can include a mainframe 204 and a factory interface 206 coupled to the mainframe 204. The mainframe 204 can include a first transfer chamber 210a and a second transfer chamber 210b connected to the first transfer chamber 210a via a first buffer chamber 221a and a second buffer chamber 221b. The mainframe 204 can further include a pair of load lock chambers 220a, 220b connected to the first transfer chamber 210a. The transfer chambers 210a, 210b, the buffer chambers 221a, 221b, and / or the load lock chambers 220a, 220b can be exposed to vacuum conditions during operation.

[0030]

[0040] The first transfer chamber 210a can include one or more processing chambers (also called process chambers) 216a-216d disposed around and coupled to it. The processing chambers 216a-216d can be coupled to the transfer chamber 210a through respective ports, which may include slit valves or the like.

[0031]

[0041] The second transfer chamber 210b can include one or more additional processing chambers 218a-218e disposed around and coupled to it. The processing chambers 218a-218e can be coupled to the transfer chamber 210b through respective ports, which can include slit valves or the like.

[0032]

[0042] Note that the transfer chambers 210a, 210b are shown with eight sides (also called facets), with a single processing chamber, load lock chamber, or buffer chamber connected to each facet. However, it should be understood that a facet may include a single processing chamber or two or more processing chambers coupled thereto. Additionally, the transfer chamber may have other shapes, such as a rectangular shape (having four facets where different facets may have different lengths), a square shape (having four facets where all facets have approximately the same length), or a radial shape with a number of facets different from eight (e.g., having five, six, or more facets).

[0033]

[0043] Processing chambers 216a-216d and 218a-218e can be adapted to perform any number of processes on substrate 202, as described above with reference to processing chambers 116a-116f, and can perform such processes under vacuum conditions.

[0034]

[0044] Transfer chamber 210a and transfer chamber 210b can include transfer chamber robots 212a, 212b, respectively.

[0035]

[0045] The factory interface (FI) 206 may be any suitable enclosure, such as, for example, an Equipment Front End Module (EFEM). The factory interface 206 may be configured to receive substrates 202 from substrate carriers (not shown) docked to various load ports (not shown) of the factory interface 206. A factory interface robot 226 may be configured to transfer substrates 202 between the substrate carriers (also called containers) and the load locks 220 a, 220 b. The factory interface 206 may, in some embodiments, be maintained in a non-reactive gas environment (e.g., using nitrogen as the non-reactive gas) at a slight positive pressure, for example.

[0036]

[0046] In some embodiments, the transfer chambers 210a, 210b, process chambers 216a-216d, 218a-218e, buffer chambers 221a, 221b, and load locks 220a, 220b can be maintained at a vacuum level. The electronics manufacturing system 200 can include one or more ports (e.g., vacuum ports) coupled to these chambers. Each of the ports can include a slit valve that separates the vacuum environment from a higher pressure (e.g., atmospheric) environment.

[0037]

[0047] Electronics manufacturing system 200 may also include a system controller 232, which may be similar to system controller 132 of FIG.

[0038]

[0048] In embodiments, the electronics manufacturing system 200 (or one or more chambers thereof) may be cleaned using a remote plasma cleaning process after assembly of the electronics manufacturing system 200. Alternatively, one or more chambers of the electronics manufacturing system 200 may be assembled and cleaned before the entire electronics device is assembled. For example, the transfer chamber 210a and the load lock chambers 220a, 220b may be assembled and cleaned together using the remote plasma cleaning process described herein. A first RPS 101a may be connected to the first transfer chamber 210a as shown to perform the remote plasma cleaning process. An exemplary plasma path 209a for such a cleaning process is shown. In another example, the transfer chamber 210b and the buffer chambers 221a, 221b may be assembled and cleaned together using the remote plasma cleaning process described herein. A second RPS 101B may be connected to the second transfer chamber 210b as shown to perform the remote plasma cleaning process. An exemplary plasma path 209a for such a cleaning process is shown. In one embodiment, the valve separating the first transfer chamber 210a from the buffer chambers 221a, 221b is sealed during the remote plasma cleaning process, and the remote plasma cleaning process using the first RPS101A and the remote plasma cleaning process using the second RPS101A are performed simultaneously.

[0039]

[0049] FIG. 3 is a flowchart of a method 300 for performing remote plasma cleaning of one or more chambers and / or other assemblies of an electronics manufacturing system according to an embodiment of the present disclosure. While method 300 is discussed with reference to a chamber, the discussed steps may also be performed on other sealable assemblies, such as a FOUP, SSP, etc. In block 305 of method 300, one or more components of the chamber(s) of the electronics manufacturing system are machined. Such machining may include, for example, milling and / or polishing of the components. In block 310, the chamber(s) is assembled using one or more components. Some or all of the components may contain organic contaminants and / or AMCs, such as aromatics, esters, phthalates, siloxanes, plastics, rubbers, polymers, etc. For example, one or more components of the chamber may contain aromatic polyesters, other polymers and / or esters, and / or other phthalates, which may be introduced by adhesives, lubricants, coatings, polymers (e.g., polymer-based lubricants), volatile organic compounds, and / or plastics used to package, seal, lubricate, protect, polish, mill, etc., and / or between the components. Specific examples of some organic contaminants that may be present are polyethylene terephthalate (PET), polyethylene, polystyrene, polyurethane, dibutyl phthalate, siloxane, benzoic acid, hydroxyl esters, hydrocarbons, ketones, aldehydes, alcohols, ethers, and dioctyl phthalate. Thus, the assembled chamber may also contain one or more of these organic contaminants.

[0040]

[0050] In block 315, after the chamber is assembled, a remote plasma source / generator (RPS) is connected to the chamber. The RPS is sealed to the opening of the chamber. In one embodiment, the remote plasma generator (RPS) is connected directly to the chamber without any piping between the outlet of the remote plasma generator that outputs the plasma and the chamber. In other embodiments, a short connector or piping is connected between the remote plasma generator and the chamber. The RPS may be connected to the chamber, for example, at a port or window of the chamber. Other ports and / or windows of the chamber may be sealed. In some examples, other chambers are connected to the chamber through one or more ports. Such ports may remain open during the remote plasma cleaning process.

[0041]

[0051] In block 320, the pressure inside the chamber (and optionally any other chambers connected to it) can be reduced to achieve a vacuum. In one example, the chamber is evacuated to a vacuum pressure of about 20-40 mTorr, or about 10-50 mTorr. Alternatively, the chamber may be maintained at or near atmospheric pressure (e.g., a pressure of about 80-100 Torr). In other embodiments, the interior of the chamber may be evacuated to any pressure between 10 mTorr and 100 Torr.

[0042]

[0052] In block 325, the interior of the chamber (or chambers) can be heated to a target temperature. In one embodiment, the target temperature is 30-120°C. In a further embodiment, the target temperature is 40-80°C. Temperatures higher than 40°C have been shown to promote outgassing of organic contaminants and / or AMCs and accelerate the cleaning process. However, some materials, such as O-rings or gaskets (e.g., heat-resistant and / or plasma-resistant O-rings or gaskets) inside the chamber may contain organic materials (e.g., additives) bonded to other materials within the O-ring or gasket. However, increasing the temperature above approximately 100°C can release organic materials from the O-ring or gasket, increasing the amount of organic contaminants. Therefore, when such O-rings or gaskets are used, the temperature is maintained below 100°C, and in one embodiment, below 80°C. In one embodiment, the temperature is increased to the set temperature during a first period. The temperature is maintained at the set temperature during a second period. After the second period of time, the temperature is reduced, for example to room temperature, for a third period of time. In some embodiments, the interior of the chamber(s) is not heated.

[0043]

[0053] In some embodiments, the chamber is maintained at an elevated temperature (e.g., about 30-120°C) for a period of time before starting to generate the plasma. This allows moisture in the chamber to evaporate before using the plasma. In one embodiment, the chamber is maintained at an elevated temperature for about 4-12 hours (e.g., about 8 hours) before flowing the plasma into the chamber. In some embodiments, heating the chamber is performed at atmospheric pressure (e.g., before performing the step of block 320).

[0044]

[0054] In block 330, the power of the RPS is set. The power at which the RPS is set depends on the volume and / or pressure inside the chamber. In embodiments, the RPS is set to a power of about 50 to 500 watts. In one embodiment where the interior of the chamber is a vacuum (e.g., 20 to 40 mTorr or 10 to 50 mTorr), a low power setting of about 50 to about 110 watts (e.g., about 80 watts) is used for the RPS. In one embodiment where the interior of the chamber is at or near atmospheric pressure (e.g., about 80 to 100 Torr), a higher power setting of about 400 to 600 watts (e.g., about 500 watts) is used.

[0045]

[0055] At block 335, a gas mixture including oxygen and a carrier gas is flowed into a remote plasma generator. In embodiments, the gas mixture can be flowed to the RPS at a flow rate of about 5 sccm (standard cubic centimeters per minute) to about 100 sccm. In one embodiment, the flow rate is about 5 sccm to about 50 sccm. The RPS may be connected to a single reservoir containing the gas mixture, or may be connected to multiple different gas reservoirs, and gases from multiple reservoirs may be mixed in the RPS or in the delivery line to the RPS. In one embodiment, the gas mixture includes about 10-30 mol% oxygen and about 70-90 mol% carrier gas. The carrier gas is or includes a non-reactive gas such as nitrogen, argon, helium, or a combination thereof. In one embodiment, the gas mixture includes about 20 mol% oxygen and about 80 mol% carrier gas. In one embodiment, the gas mixture is clean air (eg, may include about 20 mol % O2, about 79-80 mol % N2, and optionally about 1 mol % other gases).

[0046]

[0056] Experiments have shown the unexpected result that using gas mixtures with up to about 30 mol% oxygen results in improved cleaning performance compared to gas mixtures with higher levels of oxygen. In theory, plasmas based on pure oxygen or high molar percentages of oxygen should improve cleaning efficiency because there are more oxygen radicals available to interact with contaminants. However, experiments have shown that above an oxygen concentration of about 30 mol percent, cleaning efficiency decreases surprisingly.

[0047]

[0057] In block 340, the RPS generates a plasma from the gas mixture. In block 345, the plasma is delivered to the interior of the chamber to perform remote plasma cleaning of the interior of the chamber. In embodiments, the remote cleaning process is performed for approximately 5 to 15 hours. In other embodiments, the remote cleaning process may be performed for as little as 3 hours or as long as 24 hours. The plasma may be delivered for one or more of the first, second, and third periods described above. In some embodiments, the plasma is delivered while the chamber remains heated. The chamber may be heated to the same temperature used before flowing the plasma into the chamber. Alternatively, the chamber may be heated to a temperature different from the temperature to which the chamber was heated before introducing the plasma. For example, a bakeout may be performed at a first temperature in block 325, and a second temperature may be used in block 345. If the interior of the chamber is not heated, the remote plasma cleaning process may be performed for a longer period of time, such as 16 to 24 hours, 36 hours, 2 days, or other periods. Once the remote plasma process is complete, the plasma is turned off, any residual plasma, gases, and / or reactants are evacuated from the interior of the chamber, and the chamber is cooled to room temperature.

[0048]

[0058] Method 300 may be performed at the location of a manufacturer of an electronics manufacturing system (e.g., a chamber) before it is shipped to a customer. Method 300 may additionally or alternatively be performed at the location where the electronics manufacturing system is installed (e.g., a customer location). Method 300 may be performed before or after the electronics manufacturing system is fully assembled at the customer location (e.g., before or after the FI, load locks, transfer chambers, and process chambers are connected together). In embodiments where method 300 is performed at the location where the electronics manufacturing system is installed, the steps of blocks 305 and 310 may be omitted. In some embodiments, the steps of FIG. 3 may be performed in the same or a different order.

[0049]

[0059] 4 is a flowchart of another method 400 for remotely plasma cleaning one or more chambers of an electronics manufacturing system prior to shipping of the electronics manufacturing system, according to an embodiment of the present disclosure. Although method 400 is discussed with reference to a chamber, the discussed steps may also be performed on other sealable assemblies, such as FOUPs, SSPs, etc. In block 405 of method 400, an opening is created in the chamber to allow the plasma flow to enter the interior of the chamber. The opening may be created by removing a window or slit valve from the chamber. Alternatively, the opening may be created by opening a slit valve in the chamber.

[0050]

[0060] In block 410, after the chamber is assembled, a remote plasma source / generator (RPS) is connected to the chamber. The RPS is sealed to the chamber opening at a created opening (e.g., at a port location where a slit valve is opened or removed, or at a window location where a window is removed). In one embodiment, the remote plasma generator (RPS) is connected directly to the chamber without tubing disposed between the outlet of the remote plasma generator that outputs the plasma and the chamber. In other embodiments, a short connector or tubing is connected between the remote plasma generator and the chamber.

[0051]

[0061] In block 415, the interior of the chamber can be heated to a target temperature. In one embodiment, the target temperature is between 30 and 120°C. In a further embodiment, the target temperature is between 40 and 80°C. In one embodiment, the temperature is increased to the set temperature during a first period of time. The temperature is maintained at the set temperature during a second period of time. After the second period of time, the temperature is decreased, for example, to room temperature, during a third period of time.

[0052]

[0062] In some embodiments, the chamber is maintained at an elevated temperature (e.g., about 30-120°C) for a period of time before starting to generate the plasma. This allows moisture in the chamber to evaporate before using the plasma. In one embodiment, the chamber is maintained at an elevated temperature for about 4-12 hours (e.g., about 8 hours) before flowing the plasma into the chamber. In some embodiments, heating of the chamber is performed at atmospheric pressure (e.g., before performing the steps of block 320) before starting the steps of block 420. Alternatively, the steps of block 420 may be performed in parallel with the steps of block 415.

[0053]

[0063] At block 420, the pressure inside the chamber (and optionally any other chambers connected to it) can be reduced to achieve a vacuum. In one example, the chamber is evacuated to a vacuum pressure of about 20-40 mTorr, or about 10-50 mTorr. Alternatively, the chamber may be maintained at or near atmospheric pressure (e.g., a pressure of about 80-100 Torr). In other embodiments, the interior of the chamber may be evacuated to any pressure between 10 mTorr and 100 Torr.

[0054]

[0064] In block 425, the RPS generates a plasma from the gas mixture, and the plasma is delivered to the interior of the chamber to perform remote plasma cleaning of the interior of the chamber. In embodiments, the remote cleaning process is performed for approximately 5 to 15 hours. In other embodiments, the remote cleaning process may be performed for as little as 3 hours or as long as 24 hours. The plasma may be delivered for one or more of the first, second, and third periods described above. In some embodiments, the plasma is delivered while the chamber remains heated. The chamber may be heated to the same temperature used before flowing the plasma into the chamber. Alternatively, the chamber may be heated to a temperature different from the temperature to which the chamber was heated before introducing the plasma. If the interior of the chamber is not heated, the remote plasma cleaning process is performed for a longer period of time, such as 16 to 24 hours, 36 hours, 2 days, or other periods.

[0055]

[0065] In one embodiment, in block 430, the process chamber is cooled while continuing to perform the remote plasma clean. In one embodiment, this is performed for about 1-3 hours (e.g., about 2 hours). Alternatively, block 430 may be omitted. In block 435, the remote plasma clean is stopped, the RPS is disconnected from the chamber, and the chamber is allowed to cool to room temperature.

[0056]

[0066] In block 440, any slit valves or windows that were previously removed are reinstalled in the chamber. Alternatively, any open slit valves may be closed. In block 445, the chamber is prepared for shipment (e.g., to a customer).

[0057]

[0067] FIG. 5 illustrates several possible locations in an electronics manufacturing system 500 to which a remote plasma source 501 can be connected to perform remote plasma cleaning of one or more chambers of the electronics manufacturing system 500. The electronics processing system 500 in FIG. 5 corresponds to the electronics processing system 200 in FIG. 2. As shown, the transfer chambers 510A-510B of the electronics manufacturing system 500 each include multiple windows 503. Any of these windows 503 can be temporarily removed to provide access to the interior of the transfer chambers 510A-510B, and the RPS module 501 can be connected to the window 503. Additionally or alternatively, the transfer chambers 510A-510B may include multiple ports 505, and the RPS module 501 may be connected to the transfer chambers 510A-510B through any of the ports 505. In some embodiments, a slit valve is removed from the port 505 before connecting the RPS module 501 to the port. In other embodiments, port 505 is opened (e.g., by opening a slit valve) to provide a pumping path, and RPS module 501 is connected through the open port. Multiple RPS modules 501 may be connected to one or both of transfer chambers 510A-510B simultaneously to perform plasma cleaning. Alternatively, a single RPS module 501 may be connected to one or both of transfer chambers 510A-510B.

[0058]

[0068] Multiple flow simulation conditions were tested to simulate a remote plasma cleaning process in one or more chambers of an electronics manufacturing system. Under the simulation conditions, any chamber port or window in the chamber was available for mounting the RPS module. Simulation boundary conditions of a clean dry air (CDA) flow rate of 10 sccm, an O2 dissociation rate of approximately 80%, and a pressure of 1E-2 Torr were tested. The composition of the clean dry air was measured to be approximately 20.95% O2 and 79.05% N2. A reaction model of O + O = O2 with a sticking coefficient of 1E-4 was tested. For boundary conditions, steady-state simulation was used with an operating pressure of 0.01 Torr, a viscosity of 3.5E-6, a mesh size of 1.3 million nodes, and simulated chemistries of N2, O2, and O2. Simulated reactions included the following: O+O+O2→2O2 example: k=7.4x10 -33 cm 6 s -1 O+O2+O2→O2+O3 Example: k=6x10 -34 cm 6 s -1 O+O3→2O2 example: k=9x10 -15 cm 6 s -1 O+O+W→W+O2 Example: α=0.1~0.002

[0059] Here, k is the reaction rate constant and α is the sticking coefficient. Furthermore, in the equation O + O + W → W + O2 (e.g., α = 0.1 to 0.002), W represents the wall or surface, and the equation means that when an O radical collides with a wall, there is a 10% to 0.2% chance that it will be converted to O2.

[0060]

[0069] Simulations showed complete removal of organic contaminants.

[0061]

[0070] FIG. 6A shows an exemplary remote plasma source / generator (RPS) module 600 that may correspond to the RPS 101, 101a, 101b, or 501 described above. The RPS module 600 includes a knob 615 for adjusting plasma power, a port (e.g., a KF40 port) that can be sealed to a chamber port or window, a gas supply line (which may include a filter) 610, and a gas flow controller 620 that can control the gas flow rate to the RPS module 600. In one embodiment, the RPS module 600 is a low-power unit capable of achieving an output power of 1 to 100 watts. The small size of the RPS module 600 and port 605 allows the RPS module 600 to be mounted to any mainframe (e.g., a transfer chamber) or chamber body. The gas supply line and filter 610 allow for the use of various plasma chemistries.

[0062]

[0071] FIG. 6B shows an adapter 650 for connecting an RPS module to a chamber. The adapter 650 may include a base 652 that connects to the chamber, a ring or flange 654 that connects to the RPS module, and a tube or cylinder 656 that connects the base 652 to the ring 654. The base 652 may be disk-shaped and, in embodiments, may include an outer diameter corresponding to the diameter of the transfer chamber window and an inner diameter corresponding to the inner diameter of the tube or cylinder 656. The ring or flange 654 may, in embodiments, have a smaller outer diameter than the base 652. The tube or cylinder 656 may be a radical conductance tube and may have a diameter and length that controls the flow rate of radicals reaching the chamber from the RPS module. In one embodiment, the tube or cylinder 656 has a length of approximately 1 inch to minimize the distance between the remote plasma generator (RPS module) and the chamber to which it is connected. A short length of approximately 1 inch or less provides increased conductance and higher cleaning rates, as opposed to a longer length of the tube or cylinder 656. The adapter 650, in an embodiment, allows the RPS module to connect to a window port or load port of the chamber.

[0063]

[0072] 7 illustrates the operating principle of carbon removal using a remote plasma cleaning process using a mixture of oxygen and a carrier gas. As shown, a plasma generator 704 receives a flow of O molecules 706 (a gas such as clean dry air containing O) and generates O + A plasma is generated containing ions 708, electrons 710, and O radicals 712. The plasma is pumped into the chamber 702, where the O radicals 712 interact with carbon 714 on the chamber surfaces to form CO according to the equation: 2O+C→CO. The CO gas is then pumped out of the chamber. The chamber surfaces may also contain long-chain hydrocarbon contamination, which can be expressed as: x H y CO2 can react with O radicals of the oxygen plasma according to the following formula: +O→CO2 +H2O. When the chamber is heated, the H2O can be evaporated. The CO2 and evaporated H2O can then be pumped out of the chamber 702.

[0064]

[0073] In one embodiment, a test setup was used to measure the cleaning of organic contaminants using a remote plasma cleaning process. For the test setup, a quartz crystal monitor (QCM) deposited with amorphous carbon was used to measure the carbon (C) removal rate as a function of plasma power. The Sauerbrey equation was used to determine the relationship between frequency and mass / area (thickness) as follows: TIFF0007729945000001.tif19170

[0065] where f0 is the fundamental mode resonant frequency (unit: Hz), Δf is the normalized frequency change (unit: Hz), Δm is the mass change (unit: g), and A is the piezoelectric active crystal area between the electrodes of the quartz crystal monitor (unit: cm 2 ), ρ q is the density of quartz (2.648 g / cm 3 ), μ q is the shear modulus of quartz for an AT-cut crystal (2.947x10 11 gcm -1 s -2) In one embodiment, the test conditions included quartz crystal monitor Au and Ag electrodes, an initial carbon thickness of 500 Angstroms, a driving gas of air, and a pressure of 5E-3 Torr. Test results showed removal rates equivalent to those shown in FIGS. 8-9.

[0066]

[0074] In one embodiment, testing was performed using contaminated specimens in a transfer chamber. An RPS module was attached to a port in the transfer chamber. A first contaminated specimen containing organic contamination was placed near the port where the RPS module was attached. A second contaminated specimen containing organic contamination was placed as far away as possible from the port where the RPS module was attached. Prior to cleaning using the remote plasma cleaning process described herein, the contamination level of the first specimen was measured to be over 200,000 particles, while the contamination level of the second specimen could not be measured due to test equipment saturation (too many particles to measure). The remote plasma cleaning process was performed using a gas mixture containing 78% N2, 21% O2, and 1% additional gas, 80 W plasma power, a 24-hour cleaning time, room temperature, and a pressure range of 2 to 4 mTorr. After the remote plasma cleaning process, zero organic contamination was measured on the first specimen, and two particles were measured on the second specimen. Thus, the organic contamination was essentially completely removed using the remote plasma cleaning process. Tests were also conducted using the remote plasma cleaning process at 80 W plasma power, 30 minutes duration, plasma generated from clean air, and various temperatures, resulting in cleaning efficiencies of over 99% (more than 99% of the initial contamination was removed).

[0067]

[0075] After repeated testing, experiments demonstrated that the remote plasma cleaning process described in the embodiments removes all on-wafer organic contaminants on wafers placed in the tested chamber using a temperature of 50°C and a cleaning duration of 8 to 14 hours. Testing was performed on electronics manufacturing system 200 shown in FIG. 2 as well as other electronics manufacturing systems not shown herein. Contaminants measured in load lock 220a, load lock 220b, transfer chamber 210a, transfer chamber 210b, first buffer 221a, and second buffer 221b were all reduced to zero detected particles or contaminated areas for measurable contamination. Starting with a few contaminated areas / particles, the measured contamination ranged from a few contaminated areas / particles to too many contaminated areas / particles to be distinguishable from one another.

[0068]

[0076] Figure 8 shows test results for remote plasma cleaning according to an embodiment of the present disclosure. In Figure 8, the x-axis represents the RPS cleaning time in hours, and the y-axis represents the average particle count of organic particles per 50 cycles. Initially, the particle count was approximately 66, and there was a nearly linear decrease in particle count until 100% particle reduction was achieved after 8 hours. As shown, the total number of detected organic particles decreased to 0 after 8 hours of cleaning time. In the test, the gas used to generate the plasma was ambient cleanroom air, a plasma power of 80 W was used, and a pressure range of 20 to 40 mTorr was used. The chart shown shows the average particle count on the y-axis and the remote plasma cleaning time on the x-axis. As shown, the plasma cleaning completely removed the organic contamination in 8 hours. For the test, the chamber was heated to a high temperature for 8 hours before running the remote plasma cleaning process. An exemplary standard cleaning recipe can be run for approximately 10 hours. Therefore, detecting complete particle removal at 8 hours indicates that cleaning could have been completed 2 hours earlier.

[0069]

[0077] 9 shows test results for remote plasma cleaning according to an embodiment of the present disclosure. The illustrated chart shows the average particle count (per 50 cycles) on the y-axis and the remote plasma cleaning time (in hours) on the x-axis. As shown, the total number of organic particles detected decreased to 0 after 10 hours of cleaning time. Initially, approximately 80 defects were detected. After 10 hours of cleaning, 0 defects were detected.

[0070]

[0078] References throughout this specification to "one embodiment" or "an embodiment" mean that a particular feature, structure, or characteristic described in connection with that embodiment is included in at least one embodiment. Thus, the appearances of the phrase "in one embodiment" or "in an embodiment" in various places throughout this specification do not necessarily all refer to the same embodiment. Furthermore, the term "or" is intended to mean an inclusive "or" rather than an exclusive "or." When the term "about" or "approximately" is used herein, it is intended to mean that the stated nominal value is accurate to within ±10%.

[0071]

[0079] Although the method steps herein are shown and described in a particular order, the order of each method step may be changed such that certain steps are performed in reverse order and certain steps may be performed, at least in part, concurrently with other steps. In alternative embodiments, the order of separate steps or substeps may be intermittent and / or interleaved.

[0072]

[0080] The foregoing description sets forth numerous specific details, such as examples of particular systems, components, methods, etc., to provide a thorough understanding of some embodiments of the present disclosure. However, it will be apparent to those skilled in the art that at least some embodiments of the present disclosure may be practiced without these specific details. In other instances, well-known components or methods have not been described in detail or have been presented in simple block diagram form to avoid unnecessarily obscuring the present disclosure. Thus, the specific details described are merely exemplary. It may be contemplated that particular implementations may vary from these example details and still be within the scope of the present disclosure.

[0073]

[0081] It is understood that the above description is intended to be illustrative, and not limiting. Many other embodiments will be apparent to those skilled in the art upon reading and understanding the above description. The scope of the present disclosure should, therefore, be determined with reference to the appended claims, along with the full scope of equivalents to which such claims are entitled.

Claims

1. 1. A method for cleaning a transfer chamber for an electronics manufacturing system, comprising: heating the interior of the transfer chamber to a temperature of 40-100°C; flowing a gas mixture including oxygen and a carrier gas into a remote plasma generator; generating a plasma from the mixed gas with the remote plasma generator; performing a remote plasma cleaning of the transfer chamber by flowing the plasma into the interior of the transfer chamber, the plasma removing a plurality of organic contaminants from the transfer chamber; Including, The remote plasma cleaning is carried out at a temperature of 40 to 100°C. method.

2. reducing the pressure within the transfer chamber to a vacuum pressure of 10-50 mTorr, wherein the remote plasma clean is performed at the pressure of 10-50 mTorr; setting a power output of the remote plasma generator to 50-110 watts, wherein the plasma is generated at the power output of 50-110 watts; The method of claim 1 further comprising:

3. 10. The method of claim 1, further comprising setting the power of the remote plasma generator to between 50 and 500 watts, wherein the plasma is generated at the power of between 50 and 500 watts.

4. allowing a pressure within the transfer chamber to reach 80-100 Torr, wherein the remote plasma cleaning is performed at the pressure of 80-100 Torr; setting the power output of the remote plasma generator to 400-600 watts, wherein the plasma is generated at the power output of 400-600 watts; The method of claim 1 further comprising:

5. The method of claim 1 , wherein the remote plasma cleaning is performed for a duration of 5 to 15 hours.

6. The method of claim 1 , wherein the gas mixture is clean air.

7. 10. The method of claim 1, wherein the mixed gas comprises 10 to 30 mol % oxygen and 70 to 90 mol % of the carrier gas.

8. 8. The method of claim 7, wherein the carrier gas is a non-reactive gas selected from the group consisting of argon, nitrogen, and helium.

9. 2. The method of claim 1, wherein the transfer chamber is coupled to a load lock chamber, a gate separating the transfer chamber from the load lock chamber is open during the remote plasma clean, and the remote plasma clean is additionally performed on the load lock chamber by flowing the plasma into the interior of the transfer chamber.

10. The method of claim 1, wherein the gas mixture is flowed into the remote plasma generator at a flow rate between 5 sccm and 100 sccm.

11. 10. The method of claim 1, wherein the transfer chamber is coupled to a processing chamber, a gate separating the transfer chamber from the processing chamber is open during the remote plasma clean, and the remote plasma clean is additionally performed on the processing chamber by flowing the plasma into the interior of the transfer chamber.

12. 1. An electronic device processing system, comprising: a transfer chamber; a plurality of processing chambers connected to the transfer chamber; a remote plasma source connected to the transfer chamber, the remote plasma source comprising: receiving a gas mixture comprising oxygen and a carrier gas; generating a plasma from the mixed gas; a remote plasma source for supplying the plasma into the interior of the transfer chamber to perform remote plasma cleaning of the transfer chamber, the plasma removing a plurality of organic contaminants from the transfer chamber; a heater connected to or inside the transfer chamber; Equipped with The heater heats the interior of the transfer chamber to a temperature of 40-100°C, and the remote plasma cleaning is performed at a temperature of 40-100°C.

13. 13. The electronic device processing system of claim 12, further comprising a vacuum system that reduces the pressure in the interior of the transfer chamber to a vacuum pressure of 10-50 mTorr, and wherein the remote plasma cleaning is performed at the vacuum pressure of 10-50 mTorr and a power output of 50-110 Watts.

14. 13. The electronic device processing system of claim 12, wherein the remote plasma cleaning is performed at a power of 50 to 500 watts.

15. 13. The electronic device processing system of claim 12, wherein the remote plasma cleaning is performed at a pressure of 80-100 Torr and a power of 400-600 Watts.

16. 13. The electronic device processing system of claim 12, wherein the remote plasma cleaning is performed for a duration of 5 to 15 hours.

17. 13. The electronic device processing system of claim 12, wherein the mixed gas comprises 10-30 mol % oxygen and 70-90 mol % of the carrier gas.

18. 13. The electronic device processing system of claim 12, further comprising a load lock chamber connected to the transfer chamber, wherein a gate separating the transfer chamber and the load lock chamber is open during the remote plasma clean, and wherein the remote plasma clean is additionally performed on the load lock chamber by flowing the plasma into the interior of the transfer chamber.

19. 13. The electronic device processing system of claim 12, further comprising: a gate separating the transfer chamber from one of the plurality of processing chambers, the gate being open during the remote plasma cleaning, the remote plasma cleaning being additionally performed on the processing chamber by flowing plasma into the interior of the transfer chamber.

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