Method of cleaning chamber

Abstract

The embodiments disclosed herein include a method for cleaning a chamber. In one embodiment, the method includes influencing a first process gas into the chamber, wherein the first process gas reacts with a metal-organic compound in the chamber to form a first volatile compound. In one embodiment, the method further includes influencing a second process gas into the chamber, wherein the second process gas reacts with a pure metal of the metal-organic compound to form a second volatile compound. In one embodiment, the method further includes removing the first volatile compound and the second volatile compound from the chamber.

Description

Chamber Cleaning for Dry Development of Metal-Organic Photoresist This application claims the benefit of U.S. Provisional Application No. 63 / 548,355, filed on November 13, 2023, the entire content of which is hereby incorporated herein by reference. This application claims the benefit of U.S. Provisional Application No. 63 / 444,858, filed on February 10, 2023, the entire content of which is hereby incorporated herein by reference. Embodiments of this disclosure relate to the field of semiconductor processing, and more particularly to integrating cluster tools for dry development chambers for extreme ultraviolet lithography (EUV) and metrology tools for after develop inspection (ADI) and after etching inspection (AEI). Embodiments also relate to a cleaning process for removing metal-organic particles from processing chambers and load locks. For decades, lithography has been used in the semiconductor industry to create 2D and 3D patterns in microelectronic components. The lithography process involves spin coating and depositing a film (photoresist), irradiating the film with a selected pattern by an energy source (exposure), and removing (developing) the exposed (positive tone) or unexposed (negative tone) regions of the film by dissolving in a solvent. Baking will be performed to remove the residual solvent. The photoresist should be a radiation-sensitive material, and upon irradiation, the exposed portions of the film undergo a chemical transformation, resulting in a change in solubility between the exposed and unexposed regions. Utilizing this solubility change, the exposed or unexposed regions of the photoresist are removed (developed). Now, the photoresist is developed, and the pattern can be transferred to the underlying thin film or substrate by etching. After transferring the pattern, the remaining photoresist is removed, and repeating this process multiple times can give 2D and 3D structures used in microelectronic components. Several properties are important in the lithography process. These important properties include sensitivity, resolution, lower line-edge roughness (LER), etch resistance, and the ability to form thinner layers. When the sensitivity is higher, less energy is required to change the solubility of the deposited film. This enables higher efficiency in the lithography process. Resolution and LER determine how narrow features can be achieved in the lithography process. Pattern transfer requires a higher etch-resistant material to form deep structures. A higher etch-resistant material also allows for thinner films. Thinner films improve the efficiency of the lithography process. The embodiments disclosed herein include a method for cleaning a chamber. In one embodiment, the method includes flowing a first processing gas into the chamber, wherein the first processing gas reacts with a metal organic compound in the chamber to form a first volatile compound. In one embodiment, the method further includes flowing a second processing gas into the chamber, wherein the second processing gas reacts with the pure metal of the metal organic compound to form a second volatile compound. In one embodiment, the method further includes removing the first volatile compound and the second volatile compound from the chamber. The embodiments disclosed herein also include a method for cleaning a chamber having metal organic deposits on one or more inner surfaces. In one embodiment, the method includes flowing a first processing gas into the chamber, wherein the first processing gas includes hydrogen, and wherein the hydrogen reacts with the metal organic deposit to form a first volatile species, and wherein at least some of the first volatile species decomposes to redeposit pure metal on the inner surface of the chamber. In one embodiment, the method further includes flowing a second processing gas into the chamber, wherein the second processing gas includes chlorine, and wherein the chlorine reacts with the pure metal to form a second volatile species. The embodiments disclosed herein also include a load lock. In one embodiment, the load lock includes a chamber having sidewalls, a top, and a bottom, and a plurality of slot regions for supporting substrates. In one embodiment, the load lock further includes a remote plasma source (RPS), and a plurality of lines between the RPS and the chamber. In one embodiment, each line couples the RPS to one of the slot regions. Cluster tools are described herein that integrate a dry development chamber for extreme ultraviolet lithography (EUV) and metrology tools for post-development inspection (ADI) and post-etch inspection (AEI). In the following description, numerous specific details are set forth, such as the thermal gas phase process and material schemes for developing photoresist, to provide a thorough understanding of the embodiments of the present disclosure. It will be apparent to those skilled in the art that the embodiments of the present disclosure may be practiced without these specific details. In other instances, well-known aspects of integrated circuit manufacturing are not described in detail so as not to unnecessarily obscure the embodiments of the present disclosure. In addition, it should be understood that the various embodiments shown in the figures are illustrative representations and are not necessarily drawn to scale. To provide context, the photoresist systems for extreme ultraviolet (EUV) lithography are inefficient. In other words, existing photoresist material systems for EUV lithography require high doses in order to provide the desired solubility switch that allows for the development of the photoresist material. Chemically amplified resist (CAR) includes chemicals that are sensitive to EUV radiation. The chemically amplified concept uses a photochemically generated acid as a catalyst. The catalyst initiates a series of chemical transformations in the resist film, providing a gain mechanism to fully convert the exposed areas of the photoresist. The converted areas of the CAR then have an etching selectivity with respect to the unexposed areas. In this way, the development process can be used to remove the exposed areas, leaving the unexposed areas intact, or to remove the unexposed areas, leaving the exposed areas intact. Other types of lithography resists suitable for EUV lithography are organic-inorganic hybrid materials (e.g., metal oxide material systems or metal organic material systems). Such material systems are beneficial for EUV lithography due to the increased sensitivity to EUV radiation. This material system typically contains metals (e.g., Sn, Hf, Zr, etc.), oxygen, and carbon. In metal oxide or metal organic photoresist systems, exposure to EUV radiation results in cross-linking and removal of carbon. The difference in the percentage of carbon between the exposed and unexposed areas is used as a solubility switch during development. In particular, the unexposed areas with a higher carbon content are preferentially developed and etched in a negative tone by the developer solution. However, it should be understood that positive tone development may also be used in some embodiments. In many cases, the resist deposition and exposure processes are provided in a single cluster tool, as shown in Figure 1. For example, tool 100 can be used for depositing and exposing the resist. Tool 100 may include a track 104. Track 104 may include the function of depositing a photosensitive resist material on a substrate. For example, track 104 can dispense a liquid resist material on the substrate. Subsequently, the substrate is rotated at a high revolutions per minute (RPM) to evenly spread the resist material on the substrate. Track 104 may further include a heating element to bake the resist in preparation for exposing the resist. Tool 100 may also include a scanner 102. Scanner 102 can be used to expose the resist to EUV radiation or other suitable radiation (e.g., deep ultraviolet (DUV)). Scanner 102 can be a step scanner or any other suitable scanning technique. After exposure, the substrate can travel back to track 104, where post exposure bake (PEB) etc. can be implemented. In some embodiments, PEB can be used to drive chemical reactions in the resist. After exposing the resist, the resist needs to be developed. The developing process can be implemented on the track 104 including an etching environment. Generally, the development is accomplished by a wet etching chemistry. At small critical dimensions (CD) and feature sizes, due to the surface tension effect in the wet etching chemistry, it is difficult to develop features with wet etching chemistry. After the developing process, the resulting structure is sent to a metrology tool for post-development inspection (ADI). As used herein, ADI can refer to an operation of one or more of, for example, critical dimension (CD) metrology, overlay metrology, and defect inspection. In some cases, the tool 100 may also include a metrology tool 106 to inspect the resist after exposure, PEB, and development. The metrology tool 106 can include functions for imaging or otherwise analyzing the resist. For example, the metrology tool 106 can include scatterometry or any other relevant metrology system, such as CD-secondary electron microscopy (CD-SEM). If the inspection meets all requirements, the substrate is sent to an etching chamber to transfer the pattern in the resist to the underlying substrate. The etching chamber can be disposed in another tool. Therefore, it may be necessary to transport in a front opening unified pod (FOUP), and the substrate will leave the vacuum state. After etching, the substrate can be sent to the metrology tool again to perform post-etch inspection (AEI). AEI can include post-etch metrology (e.g., CD-SEM, scatterometry, etc.) and defect inspection. The defect inspection can be performed on an independent tool, such as a bright field inspection tool. As can be seen from the above process flow, the substrate needs to pass between multiple tools and chambers to fully pattern the substrate using EUV lithography. Therefore, the embodiments disclosed herein include cluster tool architectures that enable resist development, pattern transfer, and metrology all within a single tool architecture. More specifically, the developing process can be performed using a dry developing process, which allows for finer CD and feature sizes. An integrated cluster tool can achieve ADI and AEI without leaving the vacuum environment. This enables faster processing, improved results, and other efficiencies. In addition, the embodiments disclosed herein utilize a dry cleaning process that can be used to periodically clean chambers, load locks, etc. During the processing of the photoresist system, particles may deposit on the surface of the chamber. If not cleaned, the particles may redeposit on the subsequently processed substrate and cause defects or other damage. In the case of a metal-organic photoresist system, the particles will generally include metal-organic compounds. Existing cleaning processes (e.g., using NF 3No volatile compounds that can be removed from the chamber will be produced, especially when the metal component contains tin. Therefore, a new cleaning process flow is disclosed herein. Generally, a first processing gas (with or without plasma) is introduced into the chamber. The first processing gas volatilizes the metal organic particles, and these metal organic particles can be discharged from the chamber. However, a certain amount of pure metal may redeposit on the surface of the chamber. Therefore, a second processing gas (with or without plasma) is introduced into the chamber to react with the pure metal to form volatile compounds that can be removed from the chamber. In some embodiments, the first processing gas and the second processing gas may include one or more of hydrogen gas, chlorine gas, and bromine gas. In some embodiments, oxygen gas and inert gases (such as argon gas, helium gas, nitrogen gas, etc.) may also be added to the processing gas. Referring now to FIG. 2, a schematic diagram of a cluster tool 200 according to an embodiment is shown. In one embodiment, the cluster tool 200 may include a development chamber 210. More specifically, the development chamber 210 may be a dry development chamber 210. Therefore, the exposed resist layer can be developed by a dry etching process, which improves LER, LWR, CD, and overall feature size. The development chamber 210 may be any suitable chamber for a dry development process. For example, the dry development chamber 210 may be a plasma chamber. Depending on whether the resist is a positive resist or a negative resist, the plasma is ignited, and the plasma reacts with the exposed or unexposed areas of the resist and removes them. In one embodiment, the cluster tool 200 may further include an etching chamber 212. The etching chamber 212 may also be a plasma etching device. The etching chamber 212 implements a dry etching process to transfer the pattern of the resist layer to the underlying layer of the substrate (e.g., a silicon layer, an oxide layer, a nitride layer, a metal layer, or any other layer suitable for semiconductor processing). In a more specific embodiment, the underlying layer may include any number of layers. For example, the underlying layer may include a hard mask (e.g., tin-based), a hard mask (e.g., silicon carbide), and an element stack that needs to be patterned. In one embodiment, the cluster tool 200 may further include a metrology tool 206. The metrology tool 206 can be used to detect coverage errors, LER, LWR, CD, or any other parameters of the resist or the patterned substrate. In a specific embodiment, the cluster tool 200 may include a scatterometry tool. The metrology tool 206 can be used to provide ADI or AEI. Since the metrology tool 206 is integrated with the etching chamber 212 and the development chamber 210 in the cluster tool 200, the substrate does not need to leave the vacuum environment during processing. As a general example of a potential process flow using a cluster tool, the process can start with forming a pattern in a resist using a dry development chamber 210. Thereafter, ADI can be implemented by a metrology tool 206. Subsequently, the substrate is etched in an etch chamber 212. In some embodiments, the etch chamber 212 can etch the underlying layer and the hard mask in the same chamber. After etching the underlying layer and the hard mask, AEI is implemented by the metrology tool 206 to confirm that the etched pattern is fully formed. When confirmed, the substrate can be transferred back to the etch chamber 212 for additional etching to etch into the device stack. In one embodiment, the cluster tool 200 can further include a dry deposition tool 215. The dry deposition tool 215 can be used to coat a resist onto the substrate using a deposition process such as chemical vapor deposition (CVD), atomic layer deposition (ALD), or similar deposition processes. In one embodiment, the cluster tool 200 is generally shown as a simple box, and there is no connection between the metrology tool 206, the development chamber 210, and the etch chamber 212. However, as will be described in more detail below, there are transfer chambers and similar chambers between the components. For example, a load lock, a robotic transfer chamber, and similar chambers can be provided between the chambers and tools in the cluster tool 200. There can also be an equipment front end module (EFEM) for receiving FOUPs and the like. Additionally, although several chamber types are included in FIG. 2, it should be understood that an embodiment can include only the metrology tool 206 and the dry development chamber 210. Referring now to FIGS. 3A - 3F, a series of plan views depicting the layout of various cluster tools 300 according to an embodiment are shown. It should be understood from the following description that individual components (e.g., metrology tools, development chambers, etch chambers, etc.) can be arranged in many different configurations while still maintaining the advantages of being part of a single cluster tool architecture. The following cluster tools 300 are schematically shown as having a general box. Those skilled in the art will recognize that complex features (e.g., slit valves, pumping solutions, robotic transfer equipment, plasma sources, etc.) are omitted for a clearer depiction of the overall layout of the cluster tool 300. Referring now to FIG. 3A, a plan view of a cluster tool 300 according to an embodiment is shown. In one embodiment, the cluster tool 300 may include an EFEM 321. The EFEM 321 may receive a FOUP, a cassette, or the like as an entry point for substrates into the cluster tool 300. Substrates processed in the cluster tool 300 may include wafers (e.g., silicon wafers or other semiconductor wafers) having any standard form factor (e.g., 200 mm, 300 mm, 450 mm, etc.). In one embodiment, the EFEM 321 may be coupled to the remainder of the cluster tool 300 via a load lock 322. The load lock 322 may separate the atmospheric conditions in the EFEM from the vacuum conditions in the remainder of the cluster tool 300. However, in some embodiments, the EFEM may also be under vacuum pressure (e.g., a pressure higher than the pressure on the other side of the load lock 322). In one embodiment, a metrology tool 325 may be provided after the load lock 322. The metrology tool 325 may be a scatterometry tool or any other metrology tool useful for ADI or AEI applications. In one embodiment, the metrology tool 325 may be communicatively coupled to a transfer chamber 327. The transfer chamber 327 may include a robotic arm, tracks, or any suitable structure for transferring substrates between the metrology tool 325 and the remainder of the cluster tool 300. In one embodiment, one or more developing chambers 310 and one or more etching chambers 312 may be coupled to the transfer chamber 327. For example, six developing chambers 310 and four etching chambers 312 are provided in the cluster tool 300. Chambers 310 and 312 may be disposed on both sides of the transfer chamber 327 to optimize space savings. In one embodiment, the developing chamber 310 may be a dry developing chamber. A plasma source may be used in conjunction with the developing chamber 310 to develop a resist layer without any wet chemicals. However, it should be understood that a dry development process does not require a plasma source. In other words, the dry development process may or may not use a plasma source. In the case of not using a plasma source, in some embodiments, the dry development process may be a thermal dry development process. The plasma source may also be used to clean the developing chamber 310 and reduce tin contamination. For example, in some embodiments, a plasma including F 2 、NF 3 、Cl 2 、O 2A plasma etch chemistry of one or more of, and HBr is used to clean the development chamber 310. Additionally, while tin contamination is provided as an example of a material to be cleaned from the chamber, it should be understood that other metals may also pose a contamination risk. Thus, depending on the type of photoresist material used, a plasma source may also be used to clean other metals. Additionally, the etch chamber 312 may be a dry etch chamber 312 that uses plasma to etch the substrate through the resist layer. In one embodiment, the substrate may enter the EFEM, pass through the load lock 322 and the metrology tool 325, and be transported to one of the development chambers 310. After development, the substrate may be transported to the metrology tool 325 for ADI. After ADI, the substrate may be transported to one of the etch chambers 312 via the transfer chamber 327. There, the substrate may be etched through the developed resist layer. Subsequently, the substrate may be transferred back to the metrology tool 325 for AEI. Thus, the operations of resist development, ADI, substrate etching, and AEI may occur within a single cluster tool 300 without the need to leave the vacuum environment. Now referring to FIG. 3B, a plan view of a cluster tool 300 according to another embodiment is shown. The cluster tool 300 may be similar to the cluster tool 300 described in more detail above, except for the metrology tool 325. The metrology tool 325 is not between the load lock 322 and the transfer chamber 327, but rather on the end of the cluster tool 300 opposite the EFEM 321. In other words, the load lock 322 may be directly coupled to the transfer chamber 327. Such embodiments allow the substrate to be inserted into and removed from the cluster tool 300 without having to pass through the metrology tool 325. Although shown at the end of the transfer chamber 327, it should be understood that the metrology tool 325 may be coupled to the transfer chamber 327 at any location along the transfer chamber 327. Now referring to FIG. 3C, a cross-sectional view of a cluster tool 300 according to another embodiment is shown. In one embodiment, the cluster tool 300 in FIG. 3C may be similar to the cluster tool 300 in FIG. 3A, except for the positioning of the metrology tool 325. In one embodiment, the metrology tool 325 may be directly coupled to the EFEM 321. For example, the metrology tool 325 may be disposed along the edge of the EFEM 321. This allows the substrate to be directly transferred from the FOUP to the metrology tool 325 via the EFEM 321 without the need to pass through the load lock 322. In one embodiment, the development chamber 310 and the etch chamber 312 may be on opposite sides of the load lock 322 relative to the metrology tool 325. In some embodiments, both the development of the resist and the etching of the substrate may be completed before the substrate returns to the metrology tool 325 through the load lock 322. Referring now to FIG. 3D, a plan view of the cluster tool 300 is shown according to another embodiment. In the embodiment shown in FIG. 3D, the metrology tool 325 is shared between a first processing line and a second processing line. The first processing line may include a first EFEM 321A, a first load lock 322A, and a first transfer chamber 327A. The development chamber 310 and the etching chamber 312 may be coupled to the first transfer chamber 327A. The second processing line may include a second EFEM 321B, a second load lock 322B, and a second transfer chamber 327B. The development chamber 310 and the etching chamber 312 may be coupled to the second transfer chamber 327B. As shown, the metrology tool 325 is coupled to the first EFEM 321A and the second EFEM 321B. The overall structure of the cluster tool 300 may be U-shaped, with the first processing line forming a first arm, the second processing line forming a second arm, and the metrology tool 325 forming a branch between the first arm and the second arm. Referring now to FIG. 3E, a plan view of the cluster tool 300 is shown according to another embodiment. The cluster tool 300 in FIG. 3E may be similar to the cluster tool 300 in FIG. 3C, with the addition of a remote plasma source (RPS) 313. As shown, a pair of RPSs 313 may be coupled to the cluster tool 300. For example, each of the RPSs 313 may be fluidly coupled to a plurality of development chambers 310. Moving the plasma from the development chambers to the RPS 313 allows for the simplification of the development chambers 310, and a single RPS 313 can be used for multiple development chambers 310, which further simplifies the design and maintenance of the cluster tool 300. Although not shown as including the RPS 313, it should be understood that the RPS 313 solution can also be used to provide plasma to one or more etching chambers 312. The RPS 313 can be used to assist the development process in the development chambers 310. However, in other embodiments, the development process is a dry process without plasma, such as a thermal dry development process. In such cases, the RPS 313 can be used to clean the development chambers 310. For example, in some embodiments, a plasma chemistry containing one or more of F 2 , NF 3 , Cl 2 , O 2 and HBr may be used to clean the development chambers 310. Referring now to Figure 3F, a plan view of a cluster tool 300 according to another embodiment is shown. The cluster tool 300 in Figure 3F may be substantially similar to the cluster tool 300 in Figure 3C, with the addition of one or more deposition chambers 315. In one embodiment, the deposition chamber 315 may be used to deposit a lithography resist layer onto a substrate. To minimize waste, improve resist uniformity, and / or provide a compositional gradient through the thickness of the resist layer, the deposition chamber 315 may be a dry deposition chamber. For example, an atomic layer deposition (ALD) process or a chemical vapor deposition (CVD) process may be used to deposit the resist layer. In one embodiment, one or more metal-containing precursors (and optionally an oxidant) may react in the deposition chamber 315 to deposit the resist layer onto the substrate. The resist layer may be a chemically amplified resist (CAR) system or a metal-oxide resist system. Referring now to Figures 4A through 4G, a process for forming a pattern in a substrate using a cluster tool according to an embodiment is shown. In one embodiment, a patterned photoresist layer may be used to transfer the pattern into the substrate. In some embodiments, the photoresist layer may be a CAR or a metal-oxide resist. In a particular embodiment, the processing may include EUV exposure, DUV exposure, or any other suitable electromagnetic radiation. Referring now to Figure 4A, a cross-sectional view of a substrate 450 according to an embodiment is shown. In one embodiment, the substrate 450 may be a semiconductor substrate, such as a silicon wafer or the like. The illustrated substrate 450 may also be any layer used in a semiconductor manufacturing environment. For example, the substrate 450 may comprise oxide, nitride, metal, or any other material composition that needs to be patterned by lithography operations. In one embodiment, a lower layer 451 may be provided on the top surface of the substrate 450. The lower layer 451 may be a material that enhances the etching of the substrate 450. In some embodiments, the lower layer 451 may be a hard mask layer or the like. Referring now to Figure 4B, a cross-sectional view of the substrate 450 after providing a resist layer 460 on the lower layer 451 according to an embodiment is shown. In one embodiment, the resist layer 460 may be a CAR system or a metal-oxide system. The resist layer 460 may be deposited using a wet coating process (e.g., spin coating) or a dry coating process (e.g., ALD or CVD). In one embodiment, the coating process may be performed in a cluster tool or as part of a track coupled to a lithography tool. Referring now to FIG. 4C, a cross-sectional view of a substrate 450 during an exposure period according to one embodiment is shown. In one embodiment, the exposure is performed via a mask 466. The exposure can be EUV, DUV, or the like. The exposed portion (indicated by the arrow) passing through the mask 466 reacts with the resist 460 to form an exposed region 465. The exposed region can be fully converted to have an etch selectivity with respect to the remaining portion of the resist 460. In some embodiments, a post exposure bake (PEB) can be used to fully convert the exposed region 465. Referring now to FIG. 4D, a cross-sectional view of the substrate 450 after the resist 460 is developed according to one embodiment is shown. In one embodiment, the development process can be performed in a cluster tool, such as the cluster tool 300 described in more detail above. The development process can be a dry development process, which may or may not include the use of plasma. The dry development process may cause the unexposed regions to be removed. However, depending on the situation, the exposed region 465 may be removed instead of the unexposed regions of the resist 460 in a resist of the opposite tone. Referring now to FIG. 4E, a cross-sectional view of the substrate 450 when the substrate is disposed in a metrology tool 425 according to one embodiment is shown. The metrology tool 425 can be part of a cluster tool including a development chamber. Thus, the substrate 450 may not need to be removed from the vacuum environment to perform the ADI process. The ADI can include scatterometry or any other type of metrology for inspecting the results of the development process. Referring now to FIG. 4F, a cross-sectional view of the substrate 450 after a pattern transfer process according to one embodiment is shown. In one embodiment, the pattern transfer process can be implemented in an etch chamber coupled to the metrology tool 425 and the development chamber. The etch chamber can be a dry etch chamber that uses plasma to etch the underlying layer 451 and the substrate 450 to form features 454 (e.g., trenches, lines, etc.). Although referred to as an "etch chamber", it should be understood that the pattern transfer process can include both an etch and a deposition process (e.g., a sidewall deposition process). Referring now to FIG. 4G, a cross-sectional view of the substrate 450 after moving the substrate to the metrology tool 425 according to one embodiment is shown. The metrology tool can be the same tool used for ADI. However, embodiments can also include a metrology tool 425 that is different from the metrology tool used for ADI. The metrology tool 425 shown in FIG. 4G can be used to perform AEI. The metrology can include scatterometry, etc. After AEI, the substrate 450 can be removed from the cluster tool for additional processing or inspection. Referring now to FIG. 5, a flowchart of a process 570 according to an embodiment is shown. In one embodiment, process 570 may begin with an exposure process of a photoresist. The exposure process may be performed in a scanner 502 such as an EUV or DUV scanner. After exposing the resist layer, it may be baked or otherwise processed. Subsequently, the substrate with the exposed photoresist is transferred to a cluster tool 500. The cluster tool 500 may include a developer 510, such as a development chamber. The developer 510 may be a dry development tool that uses plasma to develop the exposed photoresist. After development, the substrate may be moved to a metrology tool 525 of ADI. ADI may provide feedback 571, which is provided back to the scanner 502 to improve the performance of the scanner 502. Additionally, ADI may provide feedforward data 572 to an etcher 512. The feedforward data may be used to control the etching process in order to account for certain errors in the development process. The metrology tool 525 may also be in the cluster tool 500. After ADI, the substrate is sent to an etcher 512. The etcher 512 may be disposed in the cluster tool 500. The etcher 500 transfers the pattern of the photoresist into the substrate. For example, in some embodiments, a dry etching process may be used. After etching, the substrate is sent back to the metrology tool 525 for AEI. The AEI process may provide feedback 573 back to the etcher 512 and / or provide feedback 574 back to the scanner 502. In-line metrology (e.g., ADI or AEI) provides denser sampling, as well as faster feedback and / or feedforward loops. Thus, the cluster tool described herein improves the accuracy and speed of processing substrates compared to conventional processes. The feedback and feedforward process loops may be applicable to any type of system control. In one embodiment, automated process control (APC) may be implemented using a process similar to the process described above with respect to FIG. 5. Similarly, fault defect classification (FDC) may be implemented using a process similar to the process described above with respect to FIG. 5. As described above, the processing of a photoresist system (e.g., development, etc.) may result in the formation of particulate deposits on the chamber surface. Without regular and proper cleaning, these particles may become a source of damage or defects in subsequent processed substrates. Accordingly, the embodiments disclosed herein include cleaning processes that may be used to reduce or eliminate the redeposition of particles on the substrate. Generally, the cleaning process described herein may be characterized by a dry cleaning process. In other words, the cleaning is achieved by using one or more processing gases. In some embodiments, the processing gas is radicalized by using plasma. The plasma can be any type of plasma. For example, the plasma can include an in-situ plasma source, a remote plasma source (RPS), a microwave plasma source, a capacitively coupled plasma (CCP) source, an inductively coupled plasma (ICP) source, a transformer-coupled toroidal plasma (TCTP) source, etc. However, in some embodiments, a thermal cleaning operation (i.e., without plasma) can also be used. In one embodiment, the cleaning process can be provided in any chamber within a cluster tool, similar to any cluster tool described in more detail herein. In a particular embodiment, the cleaning process can be performed in a photoresist development chamber. Other embodiments can use the cleaning process to clean chambers used for transferring substrates, such as load locks or transfer chambers. Referring now to FIG. 6, a process flow diagram of a process 640 for cleaning a chamber according to one embodiment is shown. In one embodiment, the process 640 can be implemented at any desired frequency. For example, the process 640 can be performed after processing a certain number of substrates (e.g., 1 substrate, 5 substrates, 20 substrates, etc.), after a certain duration (e.g., every hour, every 3 hours, at the start of a shift, daily, etc.), after detecting contamination on the processed substrate, or after meeting any other duration or suitable criteria. In one embodiment, the target of the process 640 can be to clean metal organic compounds deposited on the chamber surface. The metal organic compounds can be sourced from a photoresist system. The photoresist system can be a DUV or EUV photoresist, such as a metal oxide system, a metal organic system, etc. In one embodiment, the metal component can include one or more of Sn, Hf, Zr, or other suitable metal elements. The metal can be bonded to organic elements (e.g., carbon, oxygen, hydrogen, nitrogen, etc.). Processing gases suitable for removing the metal component can include hydrogen, chlorine, bromine, etc. In one embodiment, the process 640 can start from operation 641, which involves flowing a first processing gas into the chamber. In one embodiment, the first processing gas reacts with the metal-containing compound to form a first volatile compound. The first processing gas can include hydrogen, chlorine, chlorine trifluoride, or bromine. In the case of tin-based metal organic compounds, the use of hydrogen may be particularly beneficial. Hydrogen (H 2 ) can react with tin to form SnH 4 , SnH 4 is the volatile compound formed via the chemical reaction Sn + 2H 2 → SnH 4 Hydrogen can also preferentially react with the organic components to form volatile species. For example, 2H + SnO → Sn + H 2 O. Unfortunately, SnH 4 will tend to spontaneously decompose into pure Sn via the chemical reaction SnH 4 → Sn + 2H 2 Although, the decomposition may also result in the production of other Sn-containing materials via reaction with other species in the chamber. Thus, process 640 may include additional operations, which will be described in more detail below. In one embodiment, hydrogen gas can flow into the chamber via a thermal process that does not include plasma activation. Alternatively, plasma can be used to radicalize the hydrogen gas to increase its reactivity with the metal-organic compound. The plasma source can be any suitable plasma source, such as the plasma sources described in more detail above. In embodiments with RPS, oxygen gas can flow with the hydrogen gas to improve the radicalization of hydrogen gas within the RPS. Inert gases (such as argon, helium, nitrogen, etc.) can also flow with the hydrogen gas to support a more stable plasma. In one embodiment, process 640 can continue with operation 642, which includes purging the first volatile compound from the chamber. The first volatile compound can be purged using any suitable exhaust or vacuum pump configuration. The first volatile compound can include hydrogen gas that has reacted with the organic compound and a certain amount of metal elements (such as tin). Although as described above, some amount of the pure metal element (in solid form) or other metal-containing solids may remain in the chamber. In one embodiment, process 640 can continue with operation 643, which includes flowing a second processing gas into the chamber. The second processing gas reacts with the metal to form a second volatile compound. In one embodiment, the second processing gas is a different processing gas from the first processing gas. For example, when the first processing gas includes hydrogen gas, the second processing gas can include chlorine gas, chlorine trifluoride, or bromine gas. In the case of chlorine gas, the chemical reaction can include Sn + Cl 2 → SnCl 4 where SnCl 4is a volatile compound. In one embodiment, operation 643 can be implemented with or without plasma (e.g., a thermal cleaning operation). The second processing gas can include only chlorine gas, or the second processing gas can include chlorine gas with oxygen and / or an inert gas (e.g., argon, helium, nitrogen, etc.). In one embodiment, process 640 can proceed to operation 644, which includes purging the second volatile compound from the chamber. The second volatile compound can be purged using any suitable exhaust or vacuum pump configuration. The second volatile compound can include chlorine gas that reacts with pure metal elements (e.g., tin) or other metal-containing materials. In one embodiment, process 640 can be run sequentially. In other words, operations 641 to 644 can be performed one after another. For example, a first pulse of the first processing gas can flow into the chamber, followed by a second pulse of the second processing gas. In some embodiments, the purge operation 642 between the two pulses can also be omitted. In one embodiment, the first pulse and the second pulse can be of the same duration, or the first pulse and the first pulse can have different durations. The durations of the first pulse and the second pulse can range from a few seconds to one or more minutes (e.g., 1 minute, 5 minutes, 10 minutes, etc.). In one embodiment, process 640 can also be repeated any number of times. For example, operations 641 to 644 can be cycled two or more times to provide a desired cleaning level. Although sequential processing may be beneficial for some cleaning operations, embodiments can also include flowing both the first processing gas and the second processing gas simultaneously. In one embodiment, the processing conditions used during cleaning process 640 can be similar to the processing conditions used for processing the substrate. Therefore, there is no need for a significant change in temperature or pressure during the cleaning process. This allows for faster cleaning operations and increased throughput. For example, the temperature (e.g., wafer temperature) during process 640 can be between about 20°C and about 100°C, and the pressure during process 640 can be between about 1 millitorr and about 10 torr. During operations 641 to 644, the processing gas flow rate can be between about 10 sccm and 5,000 sccm. In the embodiment shown in FIG. 6, process 640 includes the flow of two separate processing gases. However, in other embodiments, sufficient cleaning can be achieved by using a single processing gas. For example, using radicalized hydrogen may be sufficient to remove the desired amount of residual deposits on the chamber surface. A longer cleaning duration may be required (compared to a two-gas process), or the single-gas process can be performed more frequently. Referring now to FIG. 7, a plan view of a cluster tool 700 according to another embodiment is shown. The cluster tool 700 in FIG. 7 may be similar to the cluster tool 700 in FIG. 3E, with the addition of RPS 713, which is coupled to the load lock 722 and the transfer chamber 727 by lines 717 and 714, respectively. In other words, the cluster tool 700 may include an EFEM 721 and a metrology tool 725, which are coupled to the transfer chamber 727 via the load lock 722. The development chamber 710 and the etching chamber 712 may also be coupled to the transfer chamber 727. As shown, a pair of RPS 713 may be coupled to the cluster tool 700. For example, each of the RPS 713 may be fluidly coupled to a plurality of development chambers 710. Moving the plasma source from the development chamber to the RPS 713 allows for the simplification of the development chamber 710, and a single RPS 713 may be used for multiple development chambers 710, which further simplifies the design and maintenance of the cluster tool 700. Although not shown as including RPS 713, it should be understood that the RPS 713 solution may also be used to provide plasma to one or more etching chambers 712. The RPS 713 may be used to assist the development process in the development chamber 710. However, in other embodiments, the development process is a dry process without plasma, such as a thermal dry development process. In some embodiments, the RPS 713 may be used to clean the development chamber 710, the load lock 722, the etching chamber 712, or the transfer chamber 727. For example, a cleaning process, such as process 640, may be implemented by using the RPS 713 to provide periodic cleaning of one or more of the development chamber 710, the load lock 722, the etching chamber 712, and the transfer chamber 727. In other words, a sequence of two processing gases (e.g., hydrogen followed by chlorine) may be used to clean the metal organic deposits on the internal chamber surfaces, similar to the embodiments described in more detail above. Referring now to FIG. 7B, a cross-sectional view of a portion of the load lock 722 according to an embodiment is shown. The load lock 722 may include a chamber 780. The chamber 780 may be divided into a plurality of slot regions by a support 781. The substrate 785 may be placed on the support 781. A robotic arm 782 may be disposed within the load lock 722 to move the substrate 785 into and out of the load lock 722. Pumping features 783 (e.g., exhaust, vacuum, etc.) may also be disposed within the load lock 722. The presence of multiple support members 781 makes it difficult to clean many areas of the load lock 722 with conventional cleaning solutions. However, due to the use of the RPS 713 solution, multiple feeds can be provided to the chamber 780. For example, dedicated feed lines 717 can be supplied to each cell area. In one embodiment, a distribution plate 786 is provided at the end of each feed line 717 to more evenly distribute the radical species from the plasma. In the illustrated embodiment, the feed lines 717 enter the chamber 780 through the sidewalls. In this way, each cell area can be accessed without being blocked by the overlying support members 781, as would be the case if the feed lines 717 were introduced from the top of the chamber 780 using a more conventional method. FIG. 8 shows a schematic diagram of an exemplary form of a machine of a computer system 800, in which a set of instructions can be executed to cause the machine to perform any one or more of the methods described herein. In alternative embodiments, the machine can be connected (e.g., networked) to a Local Area Network (LAN), an intranet, an extranet, or other machines on the Internet. The machine can operate in a client-server network environment as a server or a client machine, or as a peer machine in a peer-to-peer (or distributed) network environment. The machine can be a personal computer (PC), a tablet PC, a set-top box (STB), a Personal Digital Assistant (PDA), a cellular phone, a network appliance, a server, a network router, a switch, or a bridge, or any machine capable of executing a set of instructions (sequentially or otherwise) that specify actions to be taken by the machine. Further, although only a single machine is shown, the term "machine" shall also be taken to include any collection of machines (e.g., computers) that individually or jointly execute a set (or multiple sets) of instructions to perform any one or more of the methods described herein. The exemplary computer system 800 includes a processor 802, a main memory 804 (e.g., read-only memory (ROM), flash memory, dynamic random access memory (DRAM), etc. (such as synchronous DRAM (SDRAM) or Rambus DRAM (RDRAM))), a static memory 806 (e.g., flash memory, static random access memory (SRAM), MRAM, etc.), and an auxiliary memory 818 (e.g., a data storage device), which communicate with each other via a bus 830. Processor 802 represents one or more general-purpose processing devices, such as a microprocessor, a central processing unit, etc. More specifically, processor 802 can 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. Processor 802 can also be one or more dedicated 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. Processor 802 is configured to execute processing logic 826 for performing the operations described herein. Computer system 800 may also include a network interface device 808. Computer system 800 may also include a video display unit 810 (such as a liquid crystal display (LCD), a light emitting diode display (LED), or a cathode ray tube (CRT)), an alphanumeric input device 812 (such as a keyboard), a cursor control device 814 (such as a mouse), and a signal generating device 816 (such as a speaker). Auxiliary memory 818 may include a machine-accessible storage medium (or more specifically, a computer-readable storage medium) 832, on which one or more instruction sets (such as software 822) are stored, and the one or more instruction sets embody any one or more of the methods or functions described herein. During the execution of software 822 by computer system 800, the software may also reside, wholly or at least partially, within main memory 804 and / or within processor 802, and main memory 804 and processor 802 also constitute machine-readable storage media. Software 822 can also be sent or received over network 820 via network interface device 808. Although the machine-accessible storage medium 832 is shown as a single medium in the illustrative embodiment, the term "machine-readable storage medium" should be regarded as including a single medium or multiple media (such as a centralized or distributed database, and / or associated cache memory and servers) that store one or more instruction sets. The term "machine-readable storage medium" should also be regarded as including any medium that is capable of storing or encoding an instruction set for a machine to execute and cause the machine to perform any one or more of the methods of this disclosure. Thus, the term "machine-readable storage medium" should include, but is not limited to, solid-state memory, optical and magnetic media. In accordance with an embodiment of this disclosure, instructions are stored on a machine-accessible storage medium that cause a data processing system to perform methods of exposing a photoresist, developing the photoresist, and etching an underlying substrate. This process can be implemented at least in part using a cluster tool. The cluster tool can include a metrology tool, a development chamber, and an etching chamber. In one embodiment, the methods disclosed herein allow for improved feedback and / or feedforward control of the development and etching processes to increase speed and accuracy compared to conventional methods. Accordingly, methods for processing substrates in a cluster tool having a metrology tool, a dry development chamber, and an etching chamber are described. 100: Tool 102: Scanner 104: Track 106: Metrology tool 200: Cluster tool 206: Metrology tool 210: Development chamber 212: Etch chamber 215: Deposition tool 300: Cluster tool 310: Development chamber 312: Etch chamber 313: Remote plasma source 315: Deposition chamber 321: Equipment Front End Module 321A: First Equipment Front End Module 321B: Second Equipment Front End Module 322: Load lock 322A: First Load lock 322B: Second Load lock 3 325: Metrology tool 327: Transfer chamber 327A: First Transfer chamber 327B: Second Transfer chamber 425: Metrology tool 450: Substrate 451: Lower layer 454: Feature 460: Resist layer 465: Exposed area 466: Mask 500: Cluster tool 502: Scanner 510: Developer 512: Etcher 525: Metrology tool 570: Process 571: Feedback 572: Feedforward data 573: Feedback 574: Feedback 640: Process 641: Operation 642: Operation 643: Operation 644: Operation 700: Cluster tool 710: Development chamber 712: Etch chamber 713: Remote plasma source 714: Line 717: Feed line 721: Equipment Front End Module 722: Load lock 725: Metrology tool 727: Transfer chamber 780: Chamber 781: Support 782: Robot arm 783: Pumping feature 785: Substrate 786: Distribution plate 800: Computer system 802: Processor 804: Main memory 806: Static memory 808: Network interface device 810: Video display unit 812: Alphanumeric input device 814: Cursor control device 816: Signal generation device 818: Auxiliary memory 822: Software 826: Processing logic 830: Bus 831: Machine-accessible storage medium 832: Machine-accessible storage medium 861: Network FIG. 1 is a schematic diagram of a lithography tool according to an embodiment, the lithography tool including a track for depositing a photoresist, a scanner for exposing the photoresist, and a metrology tool. FIG. 2 is a schematic diagram of a lithography tool according to an embodiment, the lithography tool including a dry development chamber, an etch chamber, a metrology tool, and a dry deposition chamber. FIG. 3A is a plan view of a cluster tool according to an embodiment, the cluster tool including a metrology tool, a development chamber, and an etch chamber on the front end module side. FIG. 3B is a plan view of a cluster tool according to an embodiment, the cluster tool including a metrology tool, a development chamber, and an etch chamber at an end opposite to the front end module. FIG. 3C is a plan view of a cluster tool according to an embodiment, the cluster tool including a metrology tool, a development chamber, and an etching chamber coupled to a front-end module. FIG. 3D is a plan view of a cluster tool according to an embodiment, the cluster tool including a shared metrology tool between two rows of development chambers and etching chambers. FIG. 3E is a plan view of a cluster tool according to an embodiment, the cluster tool including a remote plasma source coupled to these development chambers. FIG. 3F is a plan view of a cluster tool according to an embodiment, the cluster tool including a metrology tool, a development chamber, an etching chamber, and a deposition chamber. FIG. 4A is a cross-sectional view of a substrate according to an embodiment, the substrate having an underlying layer on its surface. FIG. 4B is a cross-sectional view of a substrate according to an embodiment after providing a photoresist layer on the underlying layer. FIG. 4C is a cross-sectional view of a substrate according to an embodiment during exposure of the photoresist layer. FIG. 4D is a cross-sectional view of a substrate according to an embodiment after development of the photoresist layer. FIG. 4E is a cross-sectional view of a substrate according to an embodiment during after develop inspection (ADI). FIG. 4F is a cross-sectional view of a substrate according to an embodiment after transferring a pattern in the photoresist layer to the underlying layer and the substrate. FIG. 4G is a cross-sectional view of a substrate according to an embodiment during after etch inspection (AEI). FIG. 5 is a process flow diagram of a lithography process according to an embodiment, the process being implemented at least in part in a cluster tool including a development chamber, an etching chamber, and a metrology tool. FIG. 6 is a process flow diagram of a dry process for cleaning a chamber including metal organic particles according to an embodiment. FIG. 7A is a plan view of a cluster tool according to an embodiment, the cluster tool including a remote plasma source (RPS) coupled to a processing chamber and a load lock. FIG. 7B is a cross-sectional view of a load lock coupled to an RPS according to an embodiment. FIG. 8 shows a block diagram of an exemplary computer system according to an embodiment of the present disclosure. Domestic deposit information (please note in the order of deposit institution, date, number) None Foreign deposit information (please note in the order of deposit country, institution, date, number) None 640: Process 641: Operation 642: Operation 643: Operation 644: Operation

Claims

1. A method for cleaning a chamber, comprising the steps of: introducing hydrogen gas into the chamber, wherein the hydrogen gas reacts with tin oxide adhering to the chamber to form tin and H2O; removing the H2O; introducing chlorine trifluoride into the chamber, wherein the chlorine trifluoride reacts with the tin to form a volatile compound containing tin; and removing the volatile compound containing tin from the chamber.

2. The method as described in claim 1, wherein the hydrogen and / or the chlorine trifluoride is radicalized by a plasma source.

3. The method as described in claim 2, wherein the plasma source is an in-situ plasma source, a remote plasma source (RPS), a microwave plasma source, a capacitively coupled plasma source (CCP), an inductively coupled plasma source (ICP), or a transformer-coupled annular plasma source (TCTP).

4. The method as described in claim 1, wherein the hydrogen and the chlorine trifluoride flow sequentially into the chamber.

5. The method as claimed in claim 1, wherein the chamber is a chamber in a cluster tool that includes a metering tool, a front-end module, a developing chamber, an etching chamber, or a deposition chamber, and wherein the chamber is a photoresist developing chamber, a photoresist deposition chamber, a wafer transfer chamber, or a loading gate.

6. The method as described in claim 1, wherein the hydrogen and / or the chlorine trifluoride further comprises one or more of argon, helium and nitrogen.

7. A method for cleaning a chamber having metal deposits on one or more inner surfaces, comprising the steps of: introducing a first processing gas into the chamber, wherein the first processing gas contains hydrogen, and wherein the hydrogen reacts with tin oxide adhering to the chamber to form tin and H2O; and introducing chlorine trifluoride into the chamber, wherein the chlorine trifluoride reacts with the tin to form a volatile species containing tin.

8. The method as described in claim 7, wherein the hydrogen and / or the chlorine trifluoride is radicalized by a plasma source.

9. The method as described in claim 7, wherein a temperature within the chamber is between 20°C and 100°C.

10. The method as described in claim 7, wherein a pressure within the chamber is between 1 millitor and 10 tort.

11. The method of claim 7, wherein the chamber is a chamber in a cluster tool that includes a metering tool, a front-end module, a developing chamber, an etching chamber, or a deposition chamber, and wherein the chamber is a photoresist developing chamber, a photoresist deposition chamber, a wafer transfer chamber, or a loading gate.

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