Selective metal removal with flowable polymer

Abstract

The embodiments disclosed herein relate to a method for selectively removing metallic material from the top surface and sidewalls of a feature. The metallic material covered by a flowable polymer material remains unaffected. In some embodiments, the metallic material is formed by physical vapor deposition, resulting in a relatively thin sidewall thickness. Any metallic material remaining on the sidewalls after removal from the top surface can be etched by an additional etching process. The resulting metallic layer at the bottom of the feature facilitates selective metallic gap filling of the feature.

Description

[Technical Field]

[0001] Embodiments of this disclosure relate to a method for metal removal facilitated by a flowable polymer. More specifically, embodiments of this disclosure relate to a method for selectively removing tungsten relative to a flowable polymer within a substrate feature. [Previous Technology]

[0002] Gap filling processes are integrated into several semiconductor manufacturing processes. Gap filling processes can be used to fill gaps (or features) with insulating or conductive materials. For example, shallow trench isolation, intermetallic dielectric layers, passivation layers, and dummy gates are typically implemented using gap filling processes.

[0003] As device geometries continue to shrink (e.g., critical dimensions <20 nm, <10 nm, and smaller) and thermal budgets decrease, defect-free filling of space becomes increasingly difficult due to limitations of conventional deposition processes.

[0004] Processes for selective tungsten filling have been implemented, in which tungsten can be selectively deposited on a tungsten seed layer. Unfortunately, these processes all require a minimum seed layer thickness. Known PVD processes can provide the necessary seed layer thickness, but selective tungsten filling processes will deposit tungsten material on any exposed seed layer.

[0005] Therefore, a method is needed to remove unwanted tungsten deposits from the field and sidewall surfaces in order to achieve bottom-up filling by selective deposition process. [Summary of the Invention]

[0006] One or more embodiments of this disclosure relate to a method for selective metal removal. The method includes forming a flowable polymer film on a substrate surface in which at least one feature is formed. The at least one feature has an opening of a width at a top surface, at least one sidewall, and a bottom. The at least one feature extends a feature depth from the top surface to the bottom surface. The flowable polymer film is formed within the at least one feature and has a polymer depth less than or equal to the feature depth. At least a portion of the metal material is selectively removed from the top surface without substantially affecting any material beneath the polymer film.

[0007] Additional embodiments of this disclosure relate to a method for selective tungsten removal. The method includes depositing tungsten material on a substrate surface in which at least one feature is formed. The at least one feature has an opening of a width at a top surface, at least one sidewall, and a bottom. The at least one feature extends a feature depth from the top surface to the bottom. A flowable polymer film is formed within the at least one feature and has a polymer depth less than or equal to the feature depth. At least a portion of the tungsten material is selectively removed from the top surface without substantially affecting the tungsten material beneath the polymer film. The polymer film is removed to expose the tungsten material beneath the polymer film. The tungsten material is etched from at least one sidewall. A second metallic material is selectively deposited on the tungsten material.

Implementation Method

[0014] Before describing several exemplary embodiments of this disclosure, it will be understood that this disclosure is not limited to the details of the construction or process steps set forth in the following description. This disclosure can have other embodiments and can be practiced or carried out in various ways.

[0015] As used herein, the term “about” means approximately or nearly, and in the context of the numerical value or range described, it means a change of ±15% or less in the value. For example, values ​​differing by ±14%, ±10%, ±5%, ±2%, ±1%, ±0.5%, or ±0.1% would satisfy the definition of about.

[0016] As used in this specification and the accompanying claims, the terms "substrate" or "wafer" refer to the surface on which the process is performed, or a portion thereof. As will also be understood by those skilled in the art, unless the context clearly indicates otherwise, reference to substrate may also refer to only a portion of the substrate. Furthermore, reference to deposition on a substrate may mean a bare substrate and a substrate on which one or more films or features are deposited or formed.

[0017] As used herein, “substrate” means any substrate on which a film treatment is performed during a manufacturing process or a material surface formed on a substrate. For example, depending on the application, substrate surfaces on which treatments can be performed include materials such as silicon, silicon oxide, strained silicon, silicon on insulator (SOI), carbon-doped silicon oxide, amorphous silicon, doped silicon, germanium, gallium arsenide, and any other materials such as metals, metal nitrides, metal alloys, and other conductive materials. Substrates include, but are not limited to, semiconductor wafers. Substrates may be exposed to pretreatment processes to polish, etch, reduce, oxidize, hydroxylate, anneal, and / or bake substrate surfaces. In addition to treatments performed directly on the surface of the substrate itself, as disclosed in more detail below, any film treatment steps disclosed herein may also be performed on an underlying layer formed on the substrate, and the term “substrate surface” is intended to include such an underlying layer as indicated by the context. Therefore, for example, in the case where a film / layer or part of a film / layer has already been deposited on the substrate surface, the exposed surface of the newly deposited film / layer becomes the substrate surface.

[0018] As used herein, the term "substrate surface" means any substrate surface on which layers may be formed. A substrate surface may have one or more features formed thereon, one or more layers formed thereon, or combinations thereof. The shape of a feature can be any suitable shape, including but not limited to peaks, trenches, holes, and through-holes (circular or polygonal). As used in this regard, the term "feature" means any intentional surface irregularity. Suitable examples of features include, but are not limited to, trenches having a top, two sidewalls, and a bottom extending into the substrate; through-holes having one or more sidewalls extending into the substrate to the bottom; and slot through-holes.

[0019] As used in this specification and the appended claims, the term "selective" refers to a process that acts more on a first surface than on another second surface. Such a process is described as acting "selectively" on a first surface relative to a second surface. The term "relative" as used in this regard does not imply a physical orientation of one surface on top of another surface, but rather a relation to the thermodynamic or kinetic properties of the chemical reaction between the other surface and one surface.

[0020] The term "on" indicates that there is direct contact between components. The term "directly on" indicates that there is direct contact between components without any intermediary components.

[0021] As used in this specification and the accompanying claims, the terms "precursor", "reactant", "reactive gas" and the like are used interchangeably to refer to any gaseous species that can react with the substrate surface.

[0022] The embodiments disclosed herein advantageously provide a method for selectively removing metallic material from a substrate surface. Some embodiments advantageously provide the removal of metallic material from characteristic fields and sidewalls without removing metallic material from the bottom surface of the substrate. Further embodiments advantageously provide a method for depositing an etch-stop layer comprising a flowable organic polymer. Additional embodiments advantageously provide a method for forming a metal gap fill in a bottom-up manner.

[0023] Embodiments of the present disclosure are described by way of drawings, which illustrate processes and substrates according to one or more embodiments of the present disclosure. The processes, diagrams and resulting substrates shown are merely illustrative of the disclosed processes, and those skilled in the art will recognize that the disclosed processes are not limited to the applications shown.

[0024] Referring to the figures, this disclosure relates to a method 100 for selective metal removal. Figure 1 depicts a process flow diagram of the selective metal removal method 100 according to one or more embodiments of this disclosure. Figure 2 depicts a substrate 200 having a substrate surface in which at least one feature is formed. Figures 3 through 10 depict the substrate during processing according to one or more embodiments of this disclosure.

[0025] Figure 2 illustrates a substrate 200 having a substrate surface 205. As noted above, a substrate surface refers to the exposed surface of a substrate on which a process can be performed. The substrate surface 205 has at least one feature 210 formed thereon. Although only a single feature is illustrated in the figures, those skilled in the art will recognize that multiple features will each be affected by the disclosed method in a similar manner.

[0026] At least one feature 210 has an opening 212 having an opening width W. The opening 212 is formed in the top surface 215 of the substrate 200. The feature 210 also has one or more sidewalls 214 and extends a feature depth D from the top surface 215 to the bottom surface 216. Although straight vertical sidewalls are illustrated in the figures, the disclosed method can also be performed on inclined, irregular, or recessed sidewalls.

[0027] Although the substrate 200 shown in Figure 2 is composed of a single material 220, those skilled in the art will recognize that the top surface 215, sidewalls 214, and bottom 216 can each be composed of one or more similar or different materials. For example, the bottom of the sidewall 214 can be formed of a first material, while the upper part of the same sidewall 214 can be composed of a second material. Similarly, a thin layer can be deposited on the top surface 215 without forming a perceptible portion of the sidewall 214. Additionally, the bottom 216 can be composed of a different material than the sidewall 214.

[0028] In some embodiments, the opening width W of the opening 212 is less than or equal to about 50 nm, less than or equal to about 30 nm, less than or equal to about 20 nm, less than or equal to about 10 nm, or less than or equal to about 7 nm. In some embodiments, the opening width W is in the range of about 8 nm to about 20 nm.

[0029] In some embodiments, the feature depth D of feature 210 is greater than or equal to about 20 nm, greater than or equal to about 50 nm, greater than or equal to about 60 nm, greater than or equal to about 75 nm, or greater than or equal to about 90 nm. In some embodiments, the opening width W is in the range of about 60 nm to about 100 nm.

[0030] In some embodiments, at least one feature 210 has a depth-to-width ratio (D / W) in the range of about 1 to about 20 or in the range of about 2 to about 15.

[0031] For simplicity, reference will be made to the portion of feature 210 shown in Figure 2, and also to Figures 3 through 10. For example, the substrate 300 shown in Figure 3 is referred to as having a bottom 216. For clarity of explanation, the component symbols for the portion of feature 210 are not shown in Figures 3 through 10.

[0032] Referring to Figures 1 and 3 through 10, in some embodiments, method 100 begins with an optional operation 105 of pretreating the substrate. The pretreatment of operation 105 can be any suitable pretreatment known to those skilled in the art. Suitable pretreatments include, but are not limited to, preheating, cleaning, soaking, removal of native oxides, or deposition of a contact layer (e.g., titanium silicon (TiSi)) or a capping layer (e.g., TiSiN). In some embodiments, a layer (such as titanium silicon or TiSiN) is deposited at operation 105.

[0033] Following optional operation 105, an exemplary substrate 300 is illustrated in Figure 3. The substrate 300 includes a bottom formed by layer 310 and sidewalls and a top surface formed by layer 320. In some embodiments, layer 310 comprises a conductive material and layer 320 comprises a dielectric material. Those skilled in the art will recognize that the disclosed process can be performed on different materials and / or the illustrated layers can be arranged in different ways.

[0034] Method 100 continues in cycle 110. Cycle 110 forms a layer of metal material 410 at the bottom 216 of at least one feature 310 of the substrate 300. Cycle 110 includes a series of operations, each of which is performed sequentially and repeatably. Some operations are optional within each cycle. The given optional operations may be performed periodically during each cycle (every once, every five times, or every one hundred cycles), as needed based on predetermined parameters, or even not at all.

[0035] As shown in Figure 4, cycle 110 begins with optional operation 112. At 112, metal material 410 is deposited on substrate surface 205 of substrate 300. Metal material 410 has a bottom thickness on bottom 216, a top thickness on top surface 215, and / or a sidewall thickness on sidewall 214.

[0036] The metallic material can be deposited by any suitable method. In some embodiments, the metallic material 410 can be deposited by physical vapor deposition (PVD). In these embodiments, as shown in Figure 4, the sidewall thickness is less than the top and bottom thicknesses. In some embodiments, the top thickness is greater than the bottom thickness.

[0037] Those skilled in the art will recognize that the disclosed method can begin by forming a metallic material 410 on the substrate surface 205 of the substrate 300. Thus, operation 112 is disclosed as optional.

[0038] Cycle 100 continues to operation 114. As shown in Figure 5, at 114, a flowable polymer film 510 is formed within feature 210 of substrate 300. The polymer film 510 has a polymer depth less than or equal to the feature depth D. In other words, as a flowable film (described below), the polymer film is completely contained within feature 210 and is not present on the top surface 215 of substrate 300. In some embodiments, the polymer film has a depth in the range of about 1 nm to about 10 nm, or in the range of about 2 nm to about 5 nm.

[0039] In the disclosed method, processing parameters and reactants can be selected to limit the conformability of the deposited material, which allows the deposited material to better fill features on the substrate. The flowable material is a material that, under appropriate conditions, will flow to the lowest point on the substrate surface by gravity and / or narrow the CD space of trenches or other features by capillary action.

[0040] In some embodiments, forming a polymer film involves exposing a surface to one or more monomers. In some embodiments, the monomers are substantially composed of a single bifunctional monomer, each with a different functional group. In this way, one functional group of a monomer molecule will react with another functional group of a different monomer molecule. This will be identified by those skilled in the art as polymer "A".

[0041] In some embodiments, one or more monomers comprise or substantially consist of the following: methacrylates, styrene, benzyl alcohol, benzyl chloride, or derivatives thereof. As used in this regard, derivatives of the base molecule may contain one or more groups comprising 1 to 10 carbon atoms. For example, in some embodiments, the methacrylate compound has the general formula: wherein R is a group comprising 1 to 10 carbon atoms and R' is a group comprising 1 to 6 carbon atoms. As used in this regard, the carbon-containing groups may be straight-chain, branched, cyclic, saturated, or unsaturated. The carbon-containing groups disclosed herein do not contain groups that are reactive in the chemical polymerization processes described herein.

[0042] In addition, styrene derivative monomers may include groups on a benzene ring having 0 to 10 carbon atoms and R' groups on a vinyl group having 1 to 6 carbon atoms. Benzyl alcohol derivative monomers or benzyl chloride derivative monomers may include groups on a benzene ring having 0 to 10 carbon atoms and R' groups on a benzyl carbon having 1 to 6 carbon atoms.

[0043] In some embodiments, the monomer is essentially composed of two bifunctional monomers, each with the same functional groups. In this way, the functional groups of one monomer react with the functional groups of the second monomer. Those skilled in the art will recognize this as an "AB" polymer.

[0044] In some embodiments, the monomer comprises at least two amine, aldehyde, ketone, or alcohol groups. In some embodiments, the monomer has the general formula XR"-X, wherein X is a functional group selected from NH2, NHR', O, OH, CHO, CR'O, COOH, or COOR', R' is a group comprising 1 to 6 carbon atoms, and R'' is a group comprising 1 to 15 carbon atoms. In some embodiments, R' comprises 1 to 4 carbon atoms. In some embodiments, R'' is an ethylene or propylene group. In specific embodiments, the monomer comprises terephthalic acid (TPA, C6H4(COOH)2) and ethylenediamine (C2H4(NH2)2).

[0045] In some embodiments, the monomer includes a monofunctional monomer. When combined with the embodiments described above, those skilled in the art will recognize this as an "AC" or "ABC" polymer. Without being bound by theory, in these embodiments it is assumed that the monofunctional monomer serves as the terminal group and limits any further chain reactions.

[0046] In some embodiments, the monofunctional monomer comprises an amine, aldehyde, ketone, or alcohol group. In some embodiments, the monofunctional monomer has the general formula RX, wherein R is a group comprising 1 to 10 carbon atoms, X is a functional group selected from NH2, NHR', O, OH, or COOH, and R' is a group comprising 1 to 6 carbon atoms.

[0047] As previously mentioned, the polymer membrane 510 is fluid. In order to control the "fluidity" of the resulting membrane, it has been found that controlling the size of the resulting oligomer is necessary.

[0048] Thus, in some embodiments, a polymer film 510 is formed on a substrate maintained at a temperature in the range of 0°C to 400°C. In some embodiments, the substrate is maintained at a temperature greater than or equal to about 0°C, greater than or equal to about 30°C, greater than or equal to about 50°C, greater than or equal to about 100°C, greater than or equal to about 200°C, or greater than or equal to about 300°C. In some embodiments, the substrate is maintained at a temperature less than or equal to about 400°C, less than or equal to about 300°C, less than or equal to about 200°C, less than or equal to about 100°C, less than or equal to about 50°C, or less than or equal to about 30°C.

[0049] Additionally, other processing parameters can be controlled during the formation of the polymer film 510. Examples of controllable parameters include, but are not limited to: processing chamber pressure, monomer selection, use of inert diluent or carrier gas, monomer partial pressure, monomer pulse sequence, and pulse period to allow polymer material flow.

[0050] Cycle 110 continues to operation 116. As shown in Figure 6, at 116, at least a portion of the metal material 410 is selectively removed. The metal material 410 is removed from the top surface 215 without substantially affecting any material beneath the polymer film. When used in this respect, a process that does not "substantially affect" the material layer does not result in any reduction in volume, thickness, or composition. Those skilled in the art will recognize that the polymer film 510 serves as an etch stop layer during the removal of a portion of the metal material 410.

[0051] In some embodiments, operation 116 also removes a portion of the metal material 410 from the sidewall 214. In some embodiments, any metal material 410 present on the sidewall 214 below the upper surface of the polymer film 510 may remain intact without being removed.

[0052] In some embodiments, selective removal of the metal material 410 is performed by exposing the substrate surface 205 of the substrate 300 to NF-3 free radicals. In some embodiments, the substrate is maintained at a temperature in the range of 80°C to 110°C.

[0053] In some embodiments, selective removal of the metal material 410 is performed by the following sequence: oxidizing the metal material 410 and exposing the oxidized material to a metal halide to etch the oxidized material. In some embodiments, when the metal material contains tungsten, the metal halide contains WCl5.

[0054] Cycle 110 continues to optional operation 118. As shown in Figure 7, at 118, the polymer film 510 is removed to expose the metal material 410 beneath the polymer film 510. In some embodiments, the polymer film 510 is removed, leaving residue of the polymer film 510 on the surface of the metal material 410, illustrated as X. In some embodiments, the removal of the polymer film 510 is complete and no residue remains.

[0055] In some embodiments, the polymer film 510 is removed by exposing the substrate surface 205 of the substrate 300 to H2 plasma treatment. In some embodiments, the polymer film 510 is removed by exposing it to O2 plasma. In some embodiments, the polymer film 510 is removed by exposing it to a hot O2 environment at high temperature.

[0056] Cycle 110 continues to optional operation 119. As shown in Figure 8, at 119, residue X (if present) is cleaned from the surface of the metal material 410. The cleaning process can be any suitable process for cleaning the surface of the metal material. In some embodiments, the cleaning process does not oxidize the metal surface.

[0057] In some embodiments, at the end of cycle 110, the surface of the metal material 410 is free of any contaminants or residues of the polymer layer 410. Specifically, in some embodiments, there are no carbon or oxygen residues on the surface of the metal material 410. In some embodiments, when method 100 includes repeating cycle 110 (see below), there are no contaminants or residues between the amounts of metal material 410 deposited in subsequent cycles. In some embodiments, when method 100 includes depositing a second metal material 1010 (see below), there are no contaminants or residues between the metal material 410 and the second metal material 1010.

[0058] In some embodiments, this is achieved by a removal process of operation 118, which leaves no residue or contaminants. In some embodiments, this is achieved by performing a cleaning process of operation 119. In some embodiments, the monomer is selected so as to be free of any oxygen atoms, which could oxidize the surface of the metal material 410 during the removal of the polymer layer 510.

[0059] Method 100 continues to decision point 120. At point 120, the substrate is evaluated to determine whether the metal material 410 has reached a predetermined thickness or whether a predetermined number of cycles 110 has been performed. If the condition is met, method 100 continues to operation 130. If the condition is not met, method 100 returns to starting cycle 110 with operation 112. In those embodiments, cycle 110 is repeated to form additional material, and those skilled in the art will understand that operation 112 is often performed to deposit the necessary additional metal material. In some embodiments, the predetermined thickness is in the range of about 2 nm to about 10 nm.

[0060] Method 100 continues to optional operation 130. As shown in Figure 9, at 130, metal material 410 is etched. In some embodiments, metal material 410 is etched to remove multiple portions of metal material 410 extending upward along sidewall 214. While being etched, metal material 410 is also thinned on the bottom 216 of feature 210. Thus, those skilled in the art will recognize that metal material 410 can be deposited to a greater bottom thickness than desired in the final product to provide sacrificial material that will be removed when the metal material is etched from sidewall 214.

[0061] Unbound by theory, the inventors discovered that removing the sidewall portion of the metal material 410 simplifies the subsequent deposition of the second metal material 1010 in operation 140. The uniform, flat surface provided by operation 130 allows the second metal material 1010 to grow in a bottom-up manner, rather than growing laterally from the sidewall 214.

[0062] Method 100 continues in optional operation 140. As shown in Figure 10, at 140, a second metal material 1010 is selectively deposited on metal material 410. The deposition process is selective to the surface of metal material 410 compared to other substrate surface materials (e.g., layer 320). The selective deposition process provides a gap-filling material comprising the second metal material 1010, which is formed in a bottom-up manner and not deposited laterally from sidewall 214. In some embodiments, the second metal material is deposited without forming any voids or gaps within the second metal material 1010.

[0063] In some embodiments, the metal material 410 and the second metal material 1010 comprise the same metal. In some embodiments, the metal material 410 and the second metal material 1010 comprise different metals. In some embodiments, the first metal material comprises or is substantially composed of tungsten, molybdenum, or ruthenium.

[0064] The method may end after operation 140 or may continue with optional post-processing in optional operation 150. Optional post-processing operation 150 may be, for example, a process for modifying the properties of the deposited film (e.g., annealing or plasma treatment), an additional film deposition process for growing an additional film (e.g., additional ALD or CVD process), or an additional etching process for forming a desired predetermined device architecture. In some embodiments, optional post-processing operation 150 may be a process for modifying the properties of the deposited film. In some embodiments, optional post-processing operation 150 includes annealing the substrate 300. In some embodiments, annealing is performed at a temperature greater than or equal to about 300°C, greater than or equal to about 400°C, greater than or equal to about 500°C, greater than or equal to about 600°C, greater than or equal to about 700°C, greater than or equal to about 800°C, greater than or equal to about 900°C, or greater than or equal to about 1000°C. The annealing environment in some embodiments includes one or more of the following: an inert gas (e.g., molecular nitrogen (N₂), argon (Ar)) or a reducing gas (e.g., molecular hydrogen (H₂) or ammonia (NH₃)) or an oxidizing agent, such as, but not limited to, oxygen (O₂), ozone (O₃), or peroxide. Annealing can be performed for any suitable duration. In some embodiments, the substrate is annealed for a predetermined time ranging from about 15 seconds to about 90 minutes, or from about 1 minute to about 60 minutes.

[0065] Figure 11 is a schematic top view of an exemplary multi-chamber processing system 1100 according to an embodiment of the present disclosure. The processing system 1100 generally includes a factory interface 1102, loading gate chambers 1104, 1106, transfer chambers 1108, 1110 with corresponding transfer robots 1112, 1114, holding chambers 1116, 1118, and processing chambers 1120, 1122, 1124, 1126, 1128, 1130. As detailed herein, wafers in the processing system 1100 can be processed in the respective chambers and transferred between the respective chambers without exposing the wafers to the surrounding environment outside the processing system 1100 (e.g., the atmospheric environment, such as that present in a factory). For example, wafers can be processed in and transferred between chambers under low-pressure (e.g., less than or equal to about 300 Torr) or vacuum conditions without disrupting the low-pressure or vacuum environment between the various processes performed on the wafers in processing chamber 1100. Thus, processing system 1100 can provide an integrated solution for some processing of wafers.

[0066] Unbound by theory, this integrated environment facilitates throughput and simplifies processing methods because it eliminates the need for anti-oxidation or metal coatings. In some embodiments, the disclosed method is performed without disrupting the vacuum.

[0067] Examples of treatment systems that can be suitably modified based on the teachings provided herein include the Endura®, Producer®, or Centura® integrated treatment system or other suitable treatment systems commercially available from Applied Materials, Inc., Santa Clara, California. It will be anticipated that other treatment systems, including those from other manufacturers, may be suitable for benefiting from the examples described herein.

[0068] In the example shown in Figure 11, the factory interface 1102 includes a docking station 1140 and a factory interface robot 1142 to facilitate wafer transfer. The docking station 1140 is configured to receive one or more front-opening unified pods (FOUPs) 1144. In some examples, each factory interface robot 1142 generally includes blades 1148 disposed at one end of the respective factory interface robot 1142, which are configured to transfer wafers from the factory interface 1102 to loading gate chambers 1104, 1106.

[0069] Loading chambers 1104 and 1106 have corresponding ports 1150 and 1152 coupled to the factory interface 1102 and corresponding ports 1154 and 1156 coupled to the transfer chamber 1108. The transfer chamber 1108 further has corresponding ports 1158 and 1160 coupled to the holding chambers 1116 and 1118 and corresponding ports 1162 and 1164 coupled to the processing chambers 1120 and 1122. Similarly, the transfer chamber 1110 has corresponding ports 1166 and 1168 coupled to the holding chambers 1116 and 1118 and corresponding ports 1170, 1172, 1174, and 1176 coupled to the processing chambers 1124, 1126, 1128, and 1130. Ports 1154, 1156, 1158, 1160, 1162, 1164, 1166, 1168, 1170, 1172, 1174, and 1176 can be, for example, slit valve openings with slit valves, which are used by transfer robots 1112 and 1114 to pass through their transfer wafers and to provide a seal between the respective chambers to prevent gas transfer between them. Generally, any port is open for passing through its transfer wafer. Otherwise, the port is closed.

[0070] Loading gate chambers 1104, 1106, transfer chambers 1108, 1110, holding chambers 1116, 1118, and processing chambers 1120, 1122, 1124, 1126, 1128, 1130 may be fluidly coupled to a gas and pressure control system (not specifically shown). The gas and pressure control system may include one or more gas pumps (e.g., turbopumps, cryogenic pumps, low-vacuum pumps), gas sources, various valves, and piping fluidly coupled to the respective chambers. In operation, a factory interface robot 1142 transfers wafers from FOUP 1144 through port 1150 or 1152 to loading gate chambers 1104 or 1106. The gas and pressure control system then evacuates loading gate chambers 1104 or 1106. The gas and pressure control system further maintains the transfer chambers 1108, 1110 and the holding chambers 1116, 1118 in an internal low-pressure or vacuum environment (which may include an inert gas). Therefore, the evacuation loading gate chamber 1104 or 1106 facilitates the transfer of wafers between the atmospheric environment of, for example, the fab interface 1102 and the low-pressure or vacuum environment of the transfer chamber 1108.

[0071] While the wafer is in the emptied loading gate chamber 1104 or 1106, the transfer robot 1112 transfers the wafer through port 1154 or 1156 from the loading gate chamber 1104 or 1106 to the transfer chamber 1108. The transfer robot 1112 can then transfer the wafer through the corresponding ports 1162, 1164 to either of the processing chambers 1120, 1122 and / or between the processing chambers 120, 122 for processing, and through the corresponding ports 1158, 1160 to the holding chambers 1116, 1118 for holding to await further transfer. Similarly, the transfer robot 1114 can access wafers in holding chambers 1116 or 1118 through ports 1166 or 1168, and can transfer wafers through corresponding ports 1170, 1172, 1174, 1176 to any of the processing chambers 1124, 1126, 1128, 1130 and / or between any of these processing chambers for processing, and transfer wafers through corresponding ports 1166, 1168 to holding chambers 1116, 1118 for holding pending further transfer. The transfer and holding of wafers within and within each chamber can be conducted in a low-pressure or vacuum environment provided by a gas and pressure control system.

[0072] Processing chambers 1120, 1122, 1124, 1126, 1128, and 1130 can be any suitable chamber for processing the wafer according to method 100. In some embodiments, processing chamber 1120 can perform a pre-processing process, processing chambers 1122 and 1124 can perform a deposition process, processing chambers 1126 and 1128 can perform an etching process, and processing chamber 1130 can perform a cleaning process. Processing chamber 1120 can be a SiCoNi™ pre-cleaning chamber available from Applied Materials, Inc., Santa Clara, California. Processing chambers 1126 and 1128 can each be a Selectra™ etching chamber, MCxT chamber, or Volta chamber available from Applied Materials, Inc., Santa Clara, California.

[0073] System controller 1190 is coupled to processing system 1100 for controlling processing system 1100 or its components. For example, system controller 1190 may control the operation of processing system 1100 by directly controlling chambers 1104, 1106, 1108, 1116, 1118, 1110, 1120, 1122, 1124, 1126, 1128, and 1130 of processing system 1100, or by controlling controllers associated with chambers 1104, 1106, 1108, 1116, 1118, 1110, 1120, 1122, 1124, 1126, 1128, and 1130. In operation, system controller 1190 performs data collection and feedback from the corresponding chambers to coordinate the performance of processing system 1100.

[0074] The system controller 1190 generally includes a central processing unit (CPU) 1192, memory 1194, and support circuitry 1196. The CPU 1192 can be any type of general-purpose processor that can be used in an industrial environment. The memory 1194 or non-transitory computer-readable medium is accessible by the CPU 1192 and can be one or more memory types, such as random-access memory (RAM), read-only memory (ROM), floppy disk, hard disk, or any other form of digital storage (local or remote). The support circuitry 1196 is coupled to the CPU 1192 and may include cache memory, clock circuitry, input / output subsystems, power supply, and the like. The various methods disclosed herein can be implemented generally under the control of CPU 1192 by CPU 1192 executing computer instruction code (e.g., as a software routine) stored in memory 1194 (or in memory of a specific processing chamber). When the computer instruction code is executed by CPU 1192, CPU 1192 controls the chamber to perform the process according to the various methods.

[0075] Other processing systems may be configured differently. For example, more or fewer processing chambers may be coupled to a transfer device. In the illustrated example, the transfer device includes transfer chambers 1108, 1110 and holding chambers 1116, 1118. In other examples, more or fewer transfer chambers (e.g., one transfer chamber) and / or more or fewer holding chambers (e.g., no holding chambers) may be implemented as transfer devices in a processing system.

[0076] The process can be stored as a software routine in the memory of the system controller 1190, which, when executed by the processor, causes the processing chamber to execute the process disclosed herein. The software routine can also be stored and / or executed by a second processor (not shown) located at a hardware remotely controlled by the processor. Some or all of the methods disclosed herein can also be executed in hardware. Thus, the process can be implemented in software and executed in hardware using a computer system, as, for example, an application-specific integrated circuit or other type of hardware implementation, or as a combination of software and hardware. When executed by the processor, the software routine converts a general-purpose computer into a special-purpose computer (controller) that controls the chamber operation, enabling the process to be executed.

[0077] Embodiments disclosed herein relate to a non-transitory computer-readable medium. In one or more embodiments, the non-transitory computer-readable medium includes instructions that, when executed by a controller of a processing chamber, cause the processing chamber to perform any of the methods described herein (e.g., method 100). In one or more embodiments, the controller causes the processing chamber to perform the operation of method 100. In one or more embodiments, the controller causes the processing chamber to perform the operation of forming a polymer film on a substrate surface (operation 114). In one or more embodiments, the controller causes the processing chamber to perform the operation of removing metallic material (operation 116).

[0078] For ease of description, spatially relative terms (such as "below," "under," "lower," "above," "upper," and the like) may be used herein to describe the relationship between one element or feature shown in the figures and another element or feature. It will be understood that, in addition to the orientations depicted in the figures, the spatially relative terms are intended to cover different orientations of elements in use or operation. For example, if an element in the figures is flipped, an element described as "below" or "under" another element or feature will be oriented "above" that other element or feature. Thus, the exemplary term "below" may include both below and above orientations. Elements may be oriented in other ways (rotated 90 degrees or in other orientations) and thus the spatially relative descriptive terms used herein shall be interpreted.

[0079] Unless otherwise stated herein or explicitly denied by the context, the use of the terms "a," "an," and "the," and similar references in the context of describing the materials and methods discussed herein (particularly in the context of the following claims) shall be understood to cover both the singular and the plural. Unless otherwise stated herein, the description of value ranges herein is intended only to refer independently to a simplified method falling within that range, and each individual value is incorporated into the specification as if it were independently described herein. Unless otherwise stated herein or explicitly denied by the context, all methods described herein may be performed in any suitable order. The use of any and all instances or exemplary language (e.g., "such as") provided herein is intended only to better illustrate the materials and methods and, unless otherwise asserted, does not impose any limitation on the scope. The language in the specification should not be construed as indicating that any unclaimed element is essential to the materials and methods disclosed in practice.

[0080] Throughout this specification, references to "one embodiment," "some embodiments," "one or more embodiments," or "an embodiment" mean that a particular feature, structure, material, or characteristic described in connection with an embodiment is included in at least one embodiment of this disclosure. Therefore, the appearance of phrases such as "in one or more embodiments," "in some embodiments," "in one embodiment," or "in one embodiment" in various places throughout this specification does not necessarily refer to the same embodiment of this disclosure. In one or more embodiments, a particular feature, structure, material, or characteristic is combined in any suitable manner.

[0081] Although the disclosure herein has been described with reference to specific embodiments, it will be understood that these embodiments are merely illustrative of the principles and applications of the disclosure. Those skilled in the art will readily recognize that various modifications and variations can be made to the methods and apparatus disclosed herein without departing from the spirit and scope of the disclosure. Therefore, this disclosure is intended to include modifications and variations within the scope of the appended claims and their equivalents. [Simplified Explanation of the Diagram]

[0008] To gain a more detailed understanding of the features of this disclosure, a more specific description of the disclosure briefly summarized above can be made with reference to the embodiments, some of which are illustrated in the accompanying drawings. However, it should be noted that the drawings only illustrate common embodiments of this disclosure and are not intended to limit its scope, as this disclosure may allow for other equivalent and effective embodiments.

[0009] The embodiments described herein are shown by way of example and are not limited in the drawings, in which the same references indicate similar elements.

[0010] Figure 1 shows a process flow diagram of a method according to one or more embodiments;

[0011] Figure 2 shows a cross-sectional view of a substrate feature according to one or more embodiments;

[0012] Figures 3 through 10 show cross-sectional views of the substrate during processing according to one or more embodiments; and

[0013] Figure 11 is a schematic top view of an exemplary multi-chamber processing system according to one or more embodiments. [Biomaterial Storage]

[0083] Domestic storage information (please note in order of storage institution, date, and number): None. International storage information (please note in order of storage country, institution, date, and number): None.

Claims

1. A method for selective metal removal, the method comprising the steps of: forming a fluid polymer film on a substrate surface having at least one feature therein, the at least one feature having an opening of a width at a top surface, at least one sidewall and a bottom, the at least one feature extending a feature depth from the top surface to the bottom surface, the fluid polymer film being formed within the at least one feature and having a polymer depth less than or equal to the feature depth; selectively removing at least a portion of a metal material from the top surface without substantially affecting any material beneath the polymer film; and removing the polymer film by exposing the substrate surface to an H2 plasma treatment to expose a metal layer beneath the polymer film.

2. The method of claim 1, wherein the step of forming a polymer film comprises the step of exposing the substrate surface to one or more monomers.

3. The method as described in claim 2, wherein such monomers are substantially composed of a single, bifunctional monomer.

4. The method as described in claim 2, wherein such monomers are substantially composed of two bifunctional monomers.

5. The method as described in claim 2, wherein the monomers comprise a monofunctional terminal monomer.

6. The method of claim 1, wherein the step of selectively removing the metallic material is performed by exposing the substrate surface to NF3 free radicals.

7. The method of claim 1 further comprises the step of: depositing the metal material on the surface of the substrate prior to forming the polymer film, the metal material having a top thickness on the top surface and a bottom thickness on the bottom of the at least one feature.

8. The method of claim 7, wherein the metal material is deposited by physical vapor deposition (PVD), and the metal material has a sidewall thickness less than the top thickness and the bottom thickness.

9. The method of claim 1 further comprises the step of: selectively depositing a second metallic material on the metallic layer.

10. The method of claim 1, further comprising the steps of: depositing the metal material on the surface of the substrate prior to forming the polymer film, the metal material having a top thickness on the top surface and a bottom thickness on the bottom of the at least one feature; removing the polymer film to expose the metal material beneath the polymer film; and repeating a cycle of depositing the metal material, forming the polymer film, selectively removing the metal material, and removing the polymer film to form the metal material of a predetermined thickness on the bottom of the at least one feature.

11. The method of claim 10, wherein the predetermined thickness is in the range of about 2 nm to about 10 nm.

12. The method of claim 10, wherein there are substantially no carbon or oxygen residues between the layers of the metallic material at the bottom of the at least one feature.

13. The method of claim 1, wherein the opening width is in the range of about 8 nm to about 20 nm.

14. The method of claim 1, wherein the feature depth is in the range of about 60 nm to about 100 nm.

15. The method of claim 1, wherein the ratio of the feature depth to the opening width is in the range of about 2 to about 15.

16. The method of claim 1, wherein the polymer depth is in the range of about 1 nm to about 10 nm.

17. The method of claim 1, wherein the metallic material comprises one or more of tungsten, molybdenum or ruthenium.

18. A method for selective tungsten removal, the method comprising the steps of: depositing a tungsten material on a substrate surface having at least one feature therein, the at least one feature having an opening of a width at a top surface, at least one sidewall, and a bottom, the at least one feature extending a feature depth from the top surface to the bottom surface; forming a flowable polymer film within the at least one feature, the formed flowable polymer film having a polymer depth less than or equal to the feature depth; selectively removing at least a portion of the tungsten material from the top surface without substantially affecting the tungsten material beneath the polymer film; removing the polymer film to expose the tungsten material beneath the polymer film; etching the tungsten material from the at least one sidewall; and selectively depositing a second metal material on the tungsten material.

19. A method for selective metal removal, the method comprising the steps of: forming a fluid polymer film on a substrate surface having at least one feature therein, the at least one feature having an opening of a width at a top surface, at least one sidewall and a bottom, the at least one feature extending a feature depth from the top surface to the bottom surface, the fluid polymer film being formed within the at least one feature and having a polymer depth less than or equal to the feature depth; and selectively removing at least a portion of a metal material from the top surface without substantially affecting any material beneath the polymer film by exposing the substrate surface to NF3 free radicals.

20. The method of claim 19, wherein the step of forming a polymer film comprises the step of exposing the substrate surface to one or more monomers.

21. The method as described in claim 20, wherein such monomers are substantially composed of a single, bifunctional monomer.

22. The method of claim 20, wherein such monomers are substantially composed of two bifunctional monomers.

23. The method of claim 20, wherein the monomers comprise a monofunctional terminal monomer.

24. A method for selective metal removal, the method comprising the steps of: forming a fluid polymer film on a substrate surface having at least one feature therein, the at least one feature having an opening of a width at a top surface, at least one sidewall and a bottom, the at least one feature extending a feature depth from the top surface to the bottom surface, the fluid polymer film being formed within the at least one feature and having a polymer depth less than or equal to the feature depth, wherein the fluid polymer film is formed by exposing the substrate surface to one or more monomers, the monomers being (a) substantially composed of a single, bifunctional monomer, (b) substantially composed of two bifunctional monomers, or (c) comprising a monofunctional terminal monomer; and selectively removing at least a portion of a metal material from the top surface without substantially affecting any material beneath the polymer film.

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