Integrated pvd tungsten liner and seamless cvd tungsten fill

Abstract

A method and apparatus for forming tungsten features in a semiconductor element is provided. A method includes exposing a top opening of a feature formed in a substrate to a physical vapor deposition (PVD) process to deposit a tungsten liner layer within the feature. The PVD process is performed in a first processing region of the first processing chamber and the tungsten liner layer forms an overhang portion of the top opening of the partially obstructing feature. A substrate is transferred from a first processing region of a first processing chamber to a second processing region of a second processing chamber without breaking the vacuum. The overhang portion is exposed to nitrogen-containing radicals in the second treated region to inhibit subsequent growth of tungsten along the overhang portion. The feature is exposed to a tungsten-containing precursor gas to form a tungsten-filled layer over the tungsten liner layer within the feature.

Description

Technical Field

[0001] The present disclosure generally relates to a method and apparatus for forming thin films. In particular, the present disclosure relates to a method and apparatus for forming tungsten features in semiconductor devices. Background Art

[0002] Tungsten (W) is widely used in integrated circuit (IC) device manufacturing to form conductive features where relatively low resistance and relatively high electromigration resistance are desired. Tungsten can be used as a metal fill material to form horizontal features in the surface of a dielectric material layer, such as source contacts, drain contacts, metal gate fills, gate contacts, and interconnects. Tungsten can also be used to form vertical features through a dielectric material layer to connect other interconnect features disposed above and below it, such as vias.

[0003] As critical dimensions on IC components shrink, past manufacturing techniques encounter new obstacles. For example, during filling of features with tungsten, the tungsten fill layer may be deposited faster in the upper portion of the feature than in the lower portion due to varying feature widths and the higher concentration of the precursor gas used to deposit the tungsten fill layer. This may result in void formation within portions of the feature, particularly for high aspect ratio features.

[0004] Thus, there is a need for processes for filling features with tungsten that have no or substantially no voids and seams and that have low resistivity for a variety of film thicknesses. Summary of the invention

[0005] The present disclosure relates to a method and apparatus for forming a thin film, and more particularly, to a method and apparatus for forming a tungsten feature in a semiconductor device.

[0006] In one aspect, a method for processing a semiconductor device structure is provided. The method includes exposing at least one feature formed in a substrate to a physical vapor deposition (PVD) process to deposit a tungsten liner layer over the at least one feature. The PVD process is performed in a first processing region of a first processing chamber and the at least one feature is defined by sidewall surfaces and a bottom surface extending between the sidewall surfaces. The method further includes transferring the substrate from the first processing region of the first processing chamber to a second processing region of a second processing chamber without breaking vacuum. The method further includes exposing the tungsten liner layer to nitrogen-containing radicals in the second processing region to passivate an exposed portion of the tungsten liner layer. The tungsten liner layer formed along the bottom surface remains substantially unpassivated. The method further includes exposing the feature to a tungsten-containing precursor gas to form a tungsten fill layer over the tungsten liner layer within at least one feature in the second processing region. Forming the tungsten fill layer includes preferentially growing the tungsten fill layer from the tungsten liner layer formed along the bottom surface.

[0007] Embodiments may include one or more of the following. Exposing the features to a tungsten-containing precursor gas to form a tungsten fill layer above the tungsten liner layer includes a chemical vapor deposition (CVD) process. Exposing the tungsten liner layer to nitrogen-containing radicals in the second processing region includes generating a plasma containing nitrogen-containing radicals in a remote plasma source (RPS), wherein the plasma is formed by a process gas containing nitrogen and an inert gas, and flowing the nitrogen-containing radicals into a second processing region of a second processing chamber in which the substrate is disposed. The method further includes flowing the plasma containing nitrogen-containing radicals through an ion filter to remove substantially all ions from the plasma before flowing the nitrogen-containing radicals into the second processing region. The process gas includes from about 5% to about 20% nitrogen and argon. The method further includes alternatingly exposing the tungsten liner layer to nitrogen-containing radicals in the second processing region to passivate the exposed portion of the tungsten liner layer and exposing the features to a tungsten-containing precursor gas to form a tungsten fill layer above the tungsten liner layer.

[0008] In another aspect, a method for processing a semiconductor device structure is provided. The method includes exposing at least one feature formed in a substrate to a physical vapor deposition (PVD) process to deposit a tungsten liner layer over the at least one feature. The PVD process is performed in a first processing region of a first processing chamber and the at least one feature is defined by a sidewall surface and a bottom surface extending between the sidewall surfaces. The method further includes transferring the substrate from the first processing region of the first processing chamber to a second processing region of a second processing chamber without breaking vacuum. The method further includes exposing the tungsten liner layer to a first tungsten-containing precursor and a reducing agent to form a boron-tungsten nucleation layer over the tungsten liner layer in the second processing region. The method further includes exposing the boron-tungsten nucleation layer to nitrogen-containing radicals in the second processing region to passivate the exposed portion of the boron-tungsten nucleation layer. The method further includes exposing the feature to a second tungsten-containing precursor gas to form a tungsten fill layer over the boron-tungsten nucleation layer in at least one feature in the second processing region.

[0009] Embodiments may include one or more of the following. Exposing the features to a second tungsten-containing precursor gas to form a tungsten fill layer above the tungsten liner layer includes a chemical vapor deposition (CVD) process. Exposing the boron-tungsten nucleation layer to nitrogen-containing radicals in the second processing region includes generating a plasma containing nitrogen-containing radicals in a remote plasma source (RPS). The plasma is formed by a process gas containing nitrogen and an inert gas. The method further includes flowing the nitrogen-containing radicals into a second processing region of a second processing chamber in which the substrate is disposed. The method further includes flowing the plasma containing nitrogen-containing radicals through an ion filter to remove substantially all ions from the plasma before flowing the nitrogen-containing radicals into the second processing region. The process gas includes from about 5% to about 20% nitrogen and the remainder is an inert gas, the inert gas being argon. The method further includes alternating exposing the boron-tungsten nucleation layer to nitrogen-containing radicals in the second processing region to passivate the exposed portion of the tungsten liner layer and exposing the features to a second tungsten-containing precursor gas to form a tungsten fill layer above the tungsten liner layer. Exposing the tungsten liner layer to the first tungsten-containing precursor and the reducing agent includes alternatingly exposing the tungsten liner layer to the first tungsten-containing precursor and the reducing agent in repeated cycles. The first tungsten-containing precursor is WF6 and the reducing agent is B2H6.

[0010] In another aspect, a method for processing a semiconductor device structure is provided. The method includes exposing a top opening of a feature formed in a substrate to a physical vapor deposition (PVD) process to deposit a tungsten liner layer within the feature. The PVD process is performed in a first processing region of a first processing chamber and the tungsten liner layer forms an overhang that partially obstructs the top opening of the feature. The method further includes transferring the substrate from the first processing region of the first processing chamber to a second processing region of a second processing chamber without breaking vacuum. The method further includes exposing the overhang to nitrogen-containing radicals in the second processing region to inhibit subsequent growth of tungsten along the overhang. The method further includes exposing the feature to a tungsten-containing precursor gas to form a tungsten fill layer above the tungsten liner layer within the feature in the second processing region.

[0011] Embodiments may include one or more of the following. Exposing the features to a tungsten-containing precursor gas to form a tungsten fill layer above the tungsten liner layer includes a chemical vapor deposition (CVD) process. Exposing the tungsten liner layer to nitrogen-containing radicals in the second processing region includes generating a plasma containing nitrogen-containing radicals in a remote plasma source (RPS), wherein the plasma is formed by a process gas containing nitrogen and an inert gas, and flowing the nitrogen-containing radicals into a second processing region of a second processing chamber in which the substrate is disposed. The method further includes flowing the plasma containing nitrogen-containing radicals through an ion filter to remove substantially all ions from the plasma before flowing the nitrogen-containing radicals into the second processing region. The process gas includes from about 5% to about 20% nitrogen and the remainder is an inert gas, the inert gas being argon. The method further includes alternatingly exposing the tungsten liner layer to nitrogen-containing radicals in the second processing region to passivate the exposed portion of the tungsten liner layer and exposing the features to a tungsten-containing precursor gas to form a tungsten fill layer above the tungsten liner layer.

[0012] In another aspect, a non-transitory computer readable medium has instructions stored thereon that, when executed by a processor, cause a process to perform the operations of the apparatus and / or methods described above. BRIEF DESCRIPTION OF THE DRAWINGS

[0013] In order to be able to understand in detail the manner in which the above-mentioned features of the present disclosure are used, a more particular description of the aspects briefly summarized above may be made with reference to embodiments, some of which are shown in the accompanying drawings. However, it will be noted that the accompanying drawings only illustrate common embodiments of the present disclosure and are therefore not to be considered as limiting its scope, as the present disclosure may allow other equally effective embodiments.

[0014] Figure 1 A schematic top view of one example of a multi-chamber processing tool is shown in accordance with one or more embodiments of the present disclosure.

[0015] Figure 2Ais a schematic side view of a processing system that can be used to implement the methods set forth herein, according to one or more embodiments of the present disclosure.

[0016] Figure 2B According to one or more embodiments of the present disclosure Figure 2A A close-up cross-sectional view of a portion of a processing system is shown.

[0017] FIG. 3A to FIG. 3C A flow chart of a method for manufacturing a semiconductor element according to one or more embodiments of the present disclosure is shown.

[0018] 4A to 4H Views illustrating various stages of fabricating a semiconductor element according to one or more embodiments of the present disclosure.

[0019] To facilitate understanding, identical reference numerals have been used, where possible, to designate identical elements that are common to the figures. It is contemplated that elements and features of one embodiment may be beneficially incorporated in other embodiments without further recitation. DETAILED DESCRIPTION

[0020] The present disclosure relates to a method and apparatus for forming thin films. More particularly, the present disclosure relates to a method and apparatus for forming tungsten features in semiconductor devices.

[0021] It is challenging to deposit gap-fill metal films (e.g., tungsten-containing films) in features with ultra-high aspect ratios. At earlier nodes, larger dimensions made it possible to use nucleation followed by conformal chemical vapor deposition (CVD) to achieve metal gap fill. However, as the critical dimensions of features continue to shrink, the tops of ultra-small features tend to overhang, so conformal processes that grow films evenly over the field area or surface can close or pinch off the openings before the filling is complete, leaving gaps in the tungsten gap fill. Even in the absence of gaps, center gaps are a common result of conformal deposition due to the growth of tungsten gap fill from the sidewalls. This incomplete filling can result in high resistance in the formed element. Tungsten gap fill can also be adversely affected by the presence of impurities. For example, in some processes, there is a vacuum break between the PVD process and the CVD process. This vacuum break exposes the already deposited tungsten to the oxide, which can result in tungsten oxide (WO x ) formation. This tungsten oxide can increase resistivity and adversely affect device performance. In addition, the presence of tungsten oxide within a feature can affect the subsequent growth of tungsten gap fill in the feature, which contributes to the formation of large gaps and voids within the gap fill. In addition, tungsten oxide may dissolve faster in the CMP polishing solution, which can degrade the adhesion of tungsten, resulting in increased defects after CMP.

[0022] Various embodiments provide improved tungsten gapfill in features with reduced critical dimensions. Various embodiments eliminate vacuum break between tungsten liner and tungsten fill, which eliminates the formation of tungsten oxide between the tungsten liner and tungsten fill, resulting in improved tungsten gapfill and lower CMP defects. By eliminating the need for high resistivity layers (e.g., TiN barrier layers and nucleation layers typically used in conventional tungsten gapfill schemes), various embodiments achieve seamless tungsten gapfill using only low resistivity materials (e.g., PVD tungsten and CVD tungsten). The elimination of high resistivity layers also allows field suppression processes, such as the nitrogen plasma suppression process described herein performed directly on the tungsten liner, which also facilitates seamless tungsten gapfill.

[0023] Examples of processing systems that may be suitably modified according to the teachings provided herein include integrated processing systems or other suitable processing systems commercially available from Applied Materials, Inc. located in Santa Clara, Calif. It is contemplated that other processing systems, including those from other manufacturers, may be adapted to benefit from aspects described herein.

[0024] Figure 1 A schematic top view of an example multi-chamber processing system 100 or cluster tool that can be used to deposit a tungsten liner followed by a seamless gap fill of tungsten without breaking vacuum according to one or more embodiments of the present disclosure is shown. The processing system 100 may include one or more load lock chambers 102, 104 for transferring substrates into and out of the processing system 100. Typically, since the processing system 100 is under vacuum, the load lock chambers 102, 104 may "pump down" substrates introduced into the processing system 100. As shown in FIG. Figure 1 As shown, a first set of one or more substrate processing chambers 112, 114, 116, 118 (four are shown) are coupled to a first transfer chamber 111. A first transfer robot 110 positioned in the first transfer chamber 111 transfers substrates between the load lock chambers 102, 104 and the first set of one or more substrate processing chambers 112, 114, 116, 118. Each substrate processing chamber 112, 114, 116, 118 may be configured to perform a number of substrate processing operations, including the tungsten deposition process and nitrogen treatment process described herein, in addition to cyclical layer deposition (CLD), atomic layer deposition (ALD), chemical vapor deposition (CVD), physical vapor deposition (PVD), etching, pre-cleaning, degassing, orientation, and other substrate processes.

[0025] The first transfer robot 110 may also transfer substrates to / from one or more pass-through chambers 122, 124. The one or more pass-through chambers 122, 124 may be used to maintain ultra-high vacuum conditions while allowing substrates to be transferred within the processing system 100. Figure 1 As shown, the second group of one or more substrate processing chambers 132, 134, 135, 136, and 138 are coupled to the second transfer chamber 131. The second transfer robot 130 positioned in the second transfer chamber 131 can transfer substrates between the one or more pass-through chambers 122, 124 and the second group of one or more processing chambers 132, 134, 135, 136, and 138. Similar to the substrate processing chambers 112, 114, 116, 118, the substrate processing chambers 132, 134, 135, 136, and 138 can be equipped to perform various substrate processing operations, for example, in addition to cyclic layer deposition (CLD), atomic layer deposition (ALD), chemical vapor deposition (CVD), physical vapor deposition (PVD), etching, pre-cleaning, degassing, and orientation, the tungsten deposition process and the nitrogen treatment process described herein. Any of the substrate processing chambers 112, 114, 116, 118, 132, 134, 135, 136, and 138 may be removed from the processing system 100 if not necessary for the particular process being performed by the processing system 100.

[0026] The system controller 180 is coupled to the processing chamber 100 for controlling the processing system 100 or components thereof. For example, the system controller 180 may control the operation of the processing system 100 using direct control of the substrate processing chambers 112, 114, 116, 118, 132, 134, 135, 136, and 138 of the processing system 100 or by controlling controllers associated with the substrate processing chambers 112, 114, 116, 118, 132, 134, 135, 136, and 138. In operation, the system controller 180 enables data collection and feedback from the respective chambers to coordinate the performance of the processing system 100.

[0027] The system controller 180 generally includes a central processing unit (CPU) 182, a memory 184, and support circuits 186. The CPU 182 may be one of any form of general purpose processor that may be used in an industrial setting. The memory 184, a non-transitory computer readable medium, or a machine readable storage device is accessible by the CPU 182 and may be one or more memories, such as random access memory (RAM), read only memory (ROM), or any other form of digital storage (local or remote). The support circuits 186 are coupled to the CPU 182 and may include caches, clock circuits, input / output subsystems, power supplies, and the like. The various embodiments disclosed in the present disclosure may be implemented generally under the control of the CPU 182 by executing computer instruction code in the memory 184 (or in the memory of a particular processing chamber), for example as a computer program product or software routine. That is, the computer program product is tangibly embodied on the memory 184 (or a non-transitory computer-readable medium or machine-readable storage device). When the computer instruction code is executed by the CPU 182, the CPU 182 controls the chamber to perform operations according to various embodiments.

[0028] The instructions in the memory 184 are in the form of a program product, such as a program that implements the methods of the present disclosure. In one example, the present disclosure may be implemented as a program product stored on a computer-readable storage medium for use with a computer system. The program of the program product defines the functionality of the embodiments (including the methods described herein). Therefore, when carrying computer-readable instructions that direct the functionality of the methods described herein, the computer-readable storage medium is an embodiment of the present disclosure. The system controller 180 is configured to execute methods, such as the methods 300A-C stored in the memory 184.

[0029] In a particular embodiment, at least one of the substrate processing chambers 112, 114, 116, 118, 132, 134, 135, 136, and 138 is a PVD chamber configured to perform the PVD tungsten deposition process of operation 320 of the method 300A-C, and another one of the substrate processing chambers 112, 114, 116, 118, 132, 134, 135, 136, and 138 is a CVD chamber, for example, the processing system 200 is configured to perform operations 340-380 of the method 300A-C without breaking vacuum between any of the operations 320-380.

[0030] In operation, a substrate having features formed therein may be transferred to a first processing chamber, which is one of the substrate processing chambers 112, 114, 116, 118, 132, 134, 135, 136, and 138, in which a PVD tungsten liner is deposited over the features. The substrate may then be transferred to a second processing chamber, which is one of the substrate processing chambers 112, 114, 116, 118, 132, 134, 135, 136, and 138, in which vacuum is not broken, the PVD tungsten liner is exposed to a nitrogen plasma suppression treatment process, optionally followed by a nucleation layer deposition process in the second processing chamber, followed by a tungsten gap fill in the second processing chamber.

[0031] FIG. 2A to FIG. 2B A processing system 200 that can be used to perform the bottom-up tungsten gap fill substrate processing method described herein is schematically illustrated. Here, the processing system 200 is configured to provide different processing conditions desired for each of the nucleation process (e.g., operation 340), the nitrogen plasma suppression process (e.g., operation 350), and the selective gap fill process (e.g., operations 360-380 within a single processing chamber 202) without transferring the substrate between multiple processing chambers.

[0032] like Figure 2A As shown, the processing system 200 includes a processing chamber 202, a gas delivery system 204 fluidly coupled to the processing chamber 202, and a system controller 180. The processing chamber 202 (in Figure 2A 2 (shown in cross-section in FIG. 1 ) includes a chamber lid assembly 210, one or more sidewalls 212, and a chamber base 214, which collectively define a processing volume 215. The processing volume 215 is fluidly coupled to an exhaust 217, such as one or more vacuum pumps, for maintaining the processing volume 215 at sub-atmospheric conditions and extracting process gases and process byproducts therefrom.

[0033] The chamber lid assembly 210 includes a lid plate 216 and a showerhead 218 coupled to the lid plate 216 to define a gas distribution space 219 therewith. Here, the lid plate 216 is maintained at a desired temperature using one or more heaters 229 thermally coupled to the lid plate 216. The showerhead 218 faces a substrate support assembly 220 disposed in the processing space 215. As discussed below, the substrate support assembly 220 is configured to move a substrate support 222 between an elevated substrate processing position (as shown) and a lowered substrate transfer position (not shown), and thus move a substrate 230 disposed on the substrate support 222. When the substrate support assembly 220 is in the elevated substrate processing position, the showerhead 218 and the substrate support 222 define a processing area 221.

[0034] The gas delivery system 204 is connected to the gas inlet 223 ( Figure 2B ) is fluidly coupled to the processing chamber 202, and the gas inlet is provided through the cover plate 216. The processing or cleaning gas delivered by the gas delivery system 204 flows through the gas inlet 223 into the gas distribution space 219 and through the plurality of openings 232 ( Figure 2B ) is distributed into the processing region 221. In one embodiment that can be combined with other embodiments, the chamber lid assembly 210 further includes a perforated blocking plate 225 disposed between the gas inlet 223 and the showerhead 218. In those embodiments, the gas flowing into the gas distribution space 219 is first diffused by the perforated blocking plate 225 together with the showerhead 218 to provide a more uniform or desired distribution of the gas flow into the processing region 221.

[0035] Process gases and process byproducts are radially drawn outward from the process region 221 through an annular channel 227 surrounding the process region 221. The annular channel 227 may be formed in a first annular liner 226 disposed radially inward from one or more sidewalls 212 (as shown) or may be formed in one or more sidewalls 212. In one embodiment, which may be combined with other embodiments, the process chamber 202 includes one or more second liners 228, which are used to protect the inner surface of one or more sidewalls 212 or the chamber base 214 from corrosive gases and / or undesirable material deposition.

[0036] In one embodiment, which may be combined with other embodiments, a purge gas source 237 in fluid communication with the processing volume 215 is used to flow a chemically inert purge gas, such as argon (Ar), into a region disposed below the substrate support 222, for example, through an opening in the chamber floor 214 around the movable support shaft 262. The purge gas may be used to establish a positive pressure region (when compared to the pressure in the processing region 221) below the substrate support 222 during substrate processing. Typically, the purge gas introduced through the chamber floor 214 flows upward from the chamber floor and is drawn out of the processing volume 215 around the edge of the substrate support 222 through the annular channel 227. The purge gas reduces undesirable material deposition on surfaces below the substrate support 222 by reducing and / or preventing material precursor gases from flowing therein.

[0037] The substrate support assembly 220 includes a movable support shaft 262 and a substrate support 222 that extends sealingly through the chamber floor 214, such as surrounded by a bellows 265 in a region below the chamber floor 214, and that is disposed on the movable support shaft 262. To facilitate transferring substrates to and from the substrate support 222, the substrate support assembly 220 includes a lift pin assembly 266 that includes a plurality of lift pins 267 coupled to or disposed to engage a lift pin collar 268. The plurality of lift pins 267 are movably disposed in openings formed through the substrate support 222. When the substrate support 222 is disposed in a lowered substrate transfer position (not shown), the plurality of lift pins 267 extend over a substrate receiving surface of the substrate support 222 to lift a substrate 230 therefrom and access a backside (inactive) surface of the substrate 230 by a substrate transporter (not shown). When the substrate support 222 is in the raised or processing position (as shown), the plurality of lift pins 267 retract below the substrate receiving surface of the substrate support 222 to allow the substrate 230 to rest thereon.

[0038] The substrate 230 is transferred to and from the substrate support 222 through a door 271 (e.g., a slit valve disposed in one of the one or more sidewalls 212). Here, one or more openings in the area surrounding the door 271 (e.g., openings in the door housing) are fluidly coupled to a purge gas source 237, such as an argon source. The purge gas is used to prevent process and cleaning gases from contacting and / or degrading the seals surrounding the door, thereby extending its usable life.

[0039] The substrate support 222 is configured for vacuum chucking, wherein the substrate 230 is secured to the substrate support 222 by applying a vacuum to an interface between the substrate 230 and the substrate receiving surface. The vacuum is applied using a vacuum source 272 that is fluidly coupled to one or more channels or ports formed in the substrate receiving surface of the substrate support 222. In other embodiments, for example, where the processing chamber 202 is configured for direct plasma processing, the substrate support 222 may be configured for electrostatic chucking. In one embodiment that may be combined with other embodiments, the substrate support 222 includes one or more electrodes (not shown) coupled to a bias power supply (not shown), such as a continuous wave (CW) RF power supply or a pulsed RF power supply that supplies a bias thereto.

[0040] As shown, the substrate support assembly 220 features a dual-zone temperature control system to provide independent temperature control in different areas of the substrate support 222. The different temperature control areas of the substrate support 222 correspond to different areas of the substrate 230 disposed thereon. Here, the temperature control system includes a first heater 263 and a second heater 264. The first heater 263 is disposed in a central area of ​​the substrate support 222, and the second heater 264 is disposed radially outward from the central area to surround the first heater 263. In other embodiments, the substrate support 222 may have a single heater or more than two heaters.

[0041] In one embodiment, which may be combined with other embodiments, the substrate support assembly 220 further includes an annular shield ring 235 for preventing deposition of undesirable materials on the circumferential bevel of the substrate 230. During transfer of substrates to and from the substrate support 222, for example, when the substrate support assembly 220 is disposed in a lowered position (not shown), the shield ring 235 rests on an annular flange within the processing volume 215. When the substrate support assembly 220 is disposed in the raised or processing position, a radially outward surface of the substrate support 222 engages the annular shield ring 235 such that the shield ring 235 surrounds the substrate 230 disposed on the substrate support 222. Here, the shield ring 235 is shaped such that a radially inwardly facing portion of the shield ring 235 is disposed over the bevel of the substrate 230 when the substrate support assembly 220 is in the raised substrate processing position.

[0042] In one embodiment, which may be combined with other embodiments, the substrate support assembly 220 further includes an annular purge ring 236 disposed on the substrate support 222 to surround the substrate 230. In those embodiments, a shadow ring 235 may be disposed on the purge ring 236 when the substrate support assembly 220 is in the elevated substrate processing position. Typically, the purge ring 236 features a plurality of radially inward openings in fluid communication with a purge gas source 237. During substrate processing, the purge gas flows into an annular region defined by the shadow ring 235, the purge ring 236, the substrate support 222, and the bevel edge of the substrate 230 to prevent processing gas from entering the annular region and causing deposition of undesirable materials on the bevel edge of the substrate 230.

[0043] In one embodiment that can be combined with other embodiments, the processing chamber 202 is configured for direct plasma processing. In those embodiments, the showerhead 218 can be electrically coupled to a first power supply 231, such as an RF power supply, which supplies power to ignite and maintain a plasma of a processing gas flowing into the processing region 221 via capacitive coupling therewith. In one embodiment that can be combined with other embodiments, the processing chamber 202 includes an inductive plasma generator (not shown), and the plasma is formed by inductively coupling RF power to the processing gas.

[0044] The processing system 200 is advantageously configured to perform each of the tungsten nucleation, nitrogen plasma suppression, and bulk tungsten deposition processes of the void-free and gap-free tungsten gapfill process recipes without removing the substrate 230 from the processing chamber 202. Gases for performing the separate processes of the gapfill process recipe and cleaning residues from the interior surfaces of the processing chamber 202 are delivered to the processing chamber 202 using a gas delivery system 204 fluidly coupled to the processing chamber 202.

[0045] Generally, the gas delivery system 204 includes one or more remote plasma sources, here first and second radical generators 206A-B, a deposition gas source 240, and a conduit system 294 (e.g., a plurality of conduits 294A-F) fluidly coupling the radical generators 206A-B and the deposition gas source 240 to the chamber lid assembly 210. The gas delivery system 204 further includes a plurality of isolation valves, here first and second valves 290A-B disposed between the radical generators 206A-B and the lid plate 216, respectively, which can be used to fluidly isolate each of the radical generators 206A-B from the processing chamber 202 and from each other.

[0046] Each of the free radical generators 206A-B is characterized by a chamber body 280 that defines a Figure 2B2 and 3. The first and second plasma chamber spaces 281A-B are shown in Figure 2. Each of the free radical generators 206A-B is coupled to a corresponding power supply 293A-B. The power supply 293A-B is used to ignite and maintain a plasma 282A-B of a gas delivered to the plasma chamber space 281A-B from a corresponding first or second gas source 287A-B fluidly coupled thereto. In one embodiment that can be combined with other embodiments, the first free radical generator 206A generates free radicals used in a nitrogen plasma suppression treatment process. For example, the first free radical generator 206A can be used to ignite and maintain a treatment plasma 282A from a halogen-free gas mixture delivered from the first gas source 287A to the first plasma chamber space 281A. The second free radical generator 206B can be used to generate cleaning free radicals used in a chamber cleaning process by igniting and maintaining a cleaning plasma 282B from a halogen-containing gas mixture delivered from the second gas source 287B to the second plasma chamber space 281B.

[0047] Typically, nitrogen treatment radicals have a relatively short lifetime (when compared to halogen cleaning radicals) and may exhibit a relatively high sensitivity to recombination due to collisions with surfaces in the gas delivery system 204 and / or with other species of the process plasma effluent. Therefore, in one embodiment, which may be combined with other embodiments, the first radical generator 206A is typically positioned closer to the gas inlet 223 than the second radical generator 206, for example, to provide a relatively short travel distance from the first plasma chamber space 281A to the process region 221.

[0048] In one embodiment that may be combined with other embodiments, the first radical generator 206A is also fluidly coupled to a second gas source 287B that delivers a halogen-containing conditioning gas to the first plasma chamber space 281A for use in a plasma source conditioning process. In those embodiments, the gas delivery system 204 may further include a plurality of diverter valves 291 that are operable to direct the halogen-containing gas mixture from the second gas source 287B to the first plasma chamber space 281A.

[0049] Suitable remote plasma sources that can be used for one or both of the free radical generators 206A-B include radio frequency (RF) or very high radio frequency (VHRF) capacitively coupled plasma (CCP) sources, inductively coupled plasma (ICP) sources, microwave-induced (MW) plasma sources, electron cyclotron resonance (ECR) chambers, or high-density plasma (HDP) chambers.

[0050] As shown, the first radical generator 206A is fluidly coupled to the processing chamber 202 using first and second conduits 294A-B, which extend upward from the gas inlet 223 to connect with the outlet of the first plasma chamber space 281A. A first valve 290A disposed between the first and second conduits 294A-B is used to selectively fluidly isolate the first radical generator 206A from the processing chamber 202 and other parts of the gas delivery system 204. Typically, the first valve 290A is closed during, for example, a chamber cleaning process to prevent activated cleaning gases (e.g., halogen radicals) from flowing into the first plasma chamber space 281A and damaging its surfaces.

[0051] By using the third and fourth conduits 294C-D, the second radical generator 206B is fluidly coupled to the second conduit 294B and thus to the processing chamber 202. By using the second valve 290B disposed between the third and fourth conduits 294C-D, the second radical generator 206B is selectively isolated from the processing chamber 202 and other portions of the gas delivery system 204.

[0052] A deposition gas (e.g., a tungsten-containing precursor and a reducing agent) is delivered from the deposition gas source 240 to the processing chamber 202 using a fifth conduit 294E. As shown, the fifth conduit 294E is coupled to the second conduit 294B at a location proximate to the gas inlet 223, so that the first and second valves 290A-B can be used to isolate the first and second radical generators 206A-B from the deposition gas introduced into the processing chamber 202, respectively. In one embodiment that can be combined with other embodiments, the gas delivery system 204 further includes a sixth conduit 294F, which is coupled to the fourth conduit 294D at a location proximate to the second valve 290B. The sixth conduit 294F is fluidly coupled to a bypass gas source 238, such as an argon (Ar) gas source, which can be used to periodically purge portions of the gas delivery system 204 of undesirable residual cleaning, suppression, and / or deposition gases.

[0053] The processing system 200 described above may be used to perform each of the nucleation of operation 340, the nitrogen plasma suppression treatment of operation 350, and the tungsten gapfill deposition operations of operations 360-380, thus providing a single chamber seamless tungsten gapfill solution.

[0054] FIG. 3A to FIG. 3C Flowcharts are shown of various methods 300A-C for fabricating semiconductor components according to one or more embodiments of the present disclosure. 4A to 4H 1 shows various stages of manufacturing a semiconductor element according to one or more embodiments of the present disclosure. 4A to 4H With respect to the method 300A-C, it will be appreciated that 4A to 4H The structures disclosed in are not limited to methods 300A-C, but instead can be used alone as structures independent of methods 300A-C. Similarly, although methods 300A-C are related to 4A to 4H Description, it will be appreciated that methods 300A-C are not limited to 4A to 4H The structure disclosed in 4A to 4H The structure disclosed in stands alone.

[0055] Referring to method 300A, at operation 310, a substrate having features formed therein is provided. Figure 4A, a substrate is provided, which can be a semiconductor device structure 400, including a device substrate 410 on which one or more layers (e.g., a dielectric layer 420) are formed. The device substrate 410 can be or include a bulk semiconductor substrate, a semiconductor-on-insulator (SOI) substrate, or the like, and the bulk semiconductor substrate can be doped (e.g., with a p-type dopant or an n-type dopant) or undoped. In one embodiment that can be combined with other embodiments, the semiconductor material of the device substrate 410 can include an elemental semiconductor, such as, for example, silicon (Si) or germanium (Ge); a compound semiconductor, including, for example, silicon carbide, gallium arsenide, gallium phosphide, indium phosphide, indium arsenide, and / or indium antimonide; an alloy semiconductor, including, for example, SiGe, GaAsP, AlInAs, GaInAs, GaInP, and / or GaInAsP; a combination thereof, or the like. The device substrate 410 may include additional materials, such as a silicide layer, a metal silicide layer, a metal layer, a dielectric layer, an etch stop layer, an interlayer dielectric, or a combination thereof.

[0056] The device substrate 410 may further include integrated circuit components (not shown). As will be appreciated by those skilled in the art, a variety of integrated circuit components (such as transistors, diodes, capacitors, resistors, the like, or combinations thereof) may be formed in and / or on the device substrate 410 to produce the structural and functional requirements of the design of the resulting semiconductor device structure 400.

[0057] The element substrate 410 has a front side 410f (also referred to as a front surface) and a rear side 410b (also referred to as a rear surface) opposite to the front side 410f. A dielectric layer 420 is formed above the front side 410f of the element substrate 410. The dielectric layer 420 may include a plurality of layers. The dielectric layer 420 includes an upper surface 420u or a field region. In one embodiment that may be combined with other embodiments, the dielectric layer 420 includes silicon oxide, silicon oxynitride, silicon nitride, a combination thereof, or a plurality of layers thereof. In one embodiment that may be combined with other embodiments, the dielectric layer 420 is substantially composed of silicon oxide. Note that the aforementioned descriptors (e.g., silicon oxide) should not be interpreted as disclosing any particular stoichiometric ratio. Thus, "silicon oxide" and the like will be understood by those skilled in the art as a material substantially composed of silicon and oxygen without disclosing any specific stoichiometric ratio.

[0058] The dielectric layer 420 is patterned to form one or more features 422. In one embodiment that can be combined with other embodiments, the feature 422 can be selected from a groove, a via, a hole, or a combination thereof. In a specific embodiment, the feature 422 is a via. In one embodiment that can be combined with other embodiments, the feature 422 extends from the upper surface 420u of the dielectric layer 420 to the front side 410f of the device substrate 410. The feature 422 includes a sidewall surface 422s and a bottom surface 422b extending between the sidewall surfaces 422s. In one embodiment that can be combined with other embodiments, the sidewall surface 422 is tapered. The sidewall surface 422s can be defined by the dielectric layer 420 and the bottom surface can be defined by the device substrate 410. In one embodiment that can be combined with other embodiments, the sidewall surface 422s can be defined by the dielectric layer 420 and the bottom surface can also be defined by the dielectric layer 420. The feature 422 has a first depth "D1" from the upper surface 420u to the bottom surface 422b, and a width "W1" between the two sidewall surfaces 422s. In an embodiment that can be combined with other embodiments, the depth D1 is in the range of 2 nm to 200 nm, 3 nm to 200 nm, 5 nm to 100 nm, 2 nm to 100 nm, or 50 nm to 100 nm. In an embodiment that can be combined with other embodiments, the width W1 is in the range of 10 nm to 100 nm, 10 nm to 20 nm, 10 nm to 50 nm, or 50 nm to 100 nm. In an embodiment that can be combined with other embodiments, the feature 422 has a depth-to-width ratio (D / W) in the range of 1 to 20, 5 to 20, 10 to 20, or 15 to 20.

[0059] The substrate may be transferred into a processing region of a first processing chamber, such as any of substrate processing chambers 112, 114, 116, 118, 132, 134, 135, 136, and 138 on processing system 100. The first processing chamber may be a PVD chamber configured to deposit a tungsten liner.

[0060] At operation 320, a tungsten layer (e.g., tungsten liner 430) is formed over a surface of a feature (e.g., surface of feature 422) via a PVD process in a first processing chamber. The tungsten liner may be used as one of an adhesion layer, a seed layer, and / or a liner layer. The tungsten liner 430 may be a conformal layer or a non-conformal layer.

[0061] See also Figure 4B, a tungsten liner 430 may be formed over the sidewall surface 422s and the bottom surface 422b of the feature 422 and on the upper surface 420u or field region of the dielectric layer 420. The tungsten liner 430 may have an initial thickness in a range from about 1 Å to about 100 Å, or in a range from about 20 Å to about 80 Å, or in a range from about 50 Å to about 60 Å. In one embodiment that may be combined with other embodiments, the tungsten liner 430 may be discontinuous along, for example, the sidewall surface 422s and / or the bottom surface 422b. In one embodiment that may be combined with other embodiments, such as in Figure 4B As depicted in FIG. 4 , the tungsten liner 430 may grow faster near the top opening 423 of the feature 422, thereby creating an overhang 434 along the upper surface 420u of the dielectric layer 420 and / or the field region. The overhang 434 may partially obstruct or block the top opening of the feature 422. The overhang 434 may increase the width of the top opening from Figure 4A W1 is reduced to Figure 4B W2 shown.

[0062] At operation 330, the substrate is transferred from the first processing chamber to the second processing chamber without breaking vacuum. The second processing chamber may be used to perform the bottom-up tungsten gap fill substrate processing method described herein. The second processing chamber may be FIG. 2A to FIG. 2B Here, the processing system 200 is configured to provide different processing conditions desired for each of the optional nucleation process of operation 340, the nitrogen plasma suppression process of operation 350, and the selective gap filling process of operation 360 within a single processing chamber 202 without transferring the substrate between multiple processing chambers. The second processing chamber may be Figure 1 The second processing chamber may be one of the first set of one or more substrate processing chambers 112, 114, 116, 118 and / or one of the second set of one or more processing chambers 132, 134, 135, 136, and 138.

[0063] The substrate may be transferred from the first processing chamber to the second processing chamber under vacuum conditions without breaking vacuum, such as via the first transfer robot 110 in the first transfer chamber 111 and / or the second transfer robot 130 in the second transfer chamber 131, depending on the locations of the first and second processing chambers.

[0064] At operation 340, a nucleation layer (eg, nucleation layer 440) is optionally formed in a second processing chamber over a feature (eg, feature 422). Figure 4C, a nucleation layer 440 may be formed over the surface of the feature 422 (e.g., over the surface of the tungsten liner 430). The nucleation layer 440 may serve as a seed layer for subsequent deposition of a metal fill material. Furthermore, in an embodiment that may be combined with other embodiments, where the previously deposited tungsten liner 430 is discontinuous, for example, along the sidewall surface 422s, the nucleation layer 440 may repair the discontinuous portion of the tungsten liner 430. The nucleation layer 440 may include or be any suitable material for promoting the growth of a subsequently deposited metal fill material. The nucleation layer 440 may include or be a metal, a metal-boride (e.g., tungsten boride (BW)), or the like. The nucleation layer 440 may be formed by any suitable process for forming a tungsten-containing nucleation layer. Any suitable nucleation layer deposition process (such as ALD, CVD, cyclic chemical vapor deposition (CCVD) process, or a hybrid ALD / CVD process) may be used to form the tungsten-containing nucleation layer. In one example, one cycle of the ALD process includes boron pulse / boron purge / tungsten pulse / tungsten purge. The ALD process can be repeated for any number of cycles sufficient to deposit a nucleation layer of a target thickness. In one example, the ALD cycle is repeated for 3 to 5 cycles.

[0065] In one embodiment that can be combined with other embodiments, the nucleation layer 440 may include or be a tungsten-containing nucleation layer, for example, a boron-tungsten (BW) nucleation layer, a boron-silicon-tungsten (BSW) nucleation layer, or a silicon-tungsten (SW) nucleation layer. The nucleation layer 440 may be a conformal layer. In one embodiment that can be combined with other embodiments, the tungsten liner 430 has a nucleation layer 440 formed thereon, for example, a tungsten liner layer having a boron-tungsten nucleation layer formed thereon. In one embodiment that can be combined with other embodiments, the tungsten liner 430 and the nucleation layer 440 may be separately or collectively referred to as a tungsten-containing layer or bottom layer 446, such as Figure 4C Depicted in.

[0066] In one embodiment that may be combined with other embodiments, forming the nucleation layer 440 at operation 340 includes exposing the semiconductor device structure 400 to a tungsten-containing precursor gas at a first precursor gas flow rate, followed by exposing the semiconductor device structure 400 to a reducing agent. The reducing agent may include boron and is introduced into the processing region 221 at a reducing agent flow rate. The tungsten-containing precursor gas and the reducing agent may be cycled alternately at the reducing agent flow rate to form the nucleation layer 440 over the semiconductor device structure 400 in the feature 422. The reducing agent and the tungsten-containing precursor gas may be cycled alternately, starting with the reducing agent or the tungsten-containing precursor gas, and ending with the same starting gas or ending with a gas different from the starting gas. In one embodiment that may be combined with other embodiments, the reducing agent or the tungsten-containing precursor gas are cycled alternately, starting with the tungsten-containing precursor gas and ending with the reducing agent.

[0067] In one embodiment that may be combined with other embodiments, the nucleation layer 440 is deposited using an ALD process. The ALD process includes repeated cycles of alternatingly exposing the feature 422 to a tungsten-containing precursor and exposing the feature 422 to a reducing agent. In one embodiment that may be combined with other embodiments, the process region 221 is purged between alternating exposures. In one embodiment that may be combined with other embodiments, the process region 221 is purged continuously. Examples of suitable tungsten-containing precursors include tungsten halides, such as tungsten hexafluoride (WF6), tungsten hexachloride (WCl6), or combinations thereof. In one embodiment that may be combined with other embodiments, the tungsten-containing precursor includes WF6, and the reducing agent includes a boron-containing reagent, such as B2H6.

[0068] In one embodiment that can be combined with other embodiments, the semiconductor device structure 400 can be heated before or during the nucleation deposition process of operation 340. In one embodiment that can be combined with other embodiments, the substrate can be heated at a temperature from about 250 degrees Celsius to about 550 degrees Celsius, or at a temperature in a range from about 350 degrees Celsius to about 450 degrees Celsius. In one embodiment that can be combined with other embodiments, during the nucleation layer deposition process of operation 340, the processing region 221 is maintained at a pressure of less than or about 120 Torr, such as in a range from about 900 mTorr to about 120 Torr, in a range from about 1 Torr to about 100 Torr, or for example in a range from about 1 Torr to about 50 Torr. Exposing the semiconductor device structure 400 to the tungsten-containing precursor includes flowing the tungsten-containing precursor into the processing region 221 at a flow rate of about 100 sccm or less, such as in a range from about 10 sccm to about 60 sccm, or in a range from about 20 sccm to about 80 sccm. Exposing the semiconductor device structure 400 to the reducing agent includes flowing the reducing agent into the processing region 221 at a flow rate in a range from about 200 sccm to about 1000 sccm, such as in a range from about 300 sccm to about 750 sccm. It should be noted that the flow rates of the various deposition and treatment processes described herein are for a processing system configured to process a 300 mm diameter substrate. Appropriate scaling can be used for processing systems configured to process substrates of different sizes.

[0069] In one embodiment, which may be combined with other embodiments, the tungsten-containing precursor and the reducing agent are each flowed into the processing region 221 for a duration in a range from about 0.1 seconds to about 10 seconds, such as in a range from about 0.5 seconds to about 5 seconds. The processing region 221 may be purged between alternating exposures by flowing a purge gas, such as argon (Ar) or hydrogen, into the processing region 221 for a duration in a range from about 0.1 seconds to about 10 seconds, such as in a range from about 0.5 seconds to about 5 seconds. Typically, repeated cycles of the nucleation process continue until the nucleation layer 440 has a thickness in a range from about 10 Å to about 200 Å, such as in a range from about 10 Å to about 150 Å, or in a range from about 20 Å to about 150 Å. The nucleation layer 440 is disposed along the sidewall surface 422s and / or the bottom surface 422b of the feature 422, such as above the tungsten liner 430. The nucleation layer 440 may also contribute to the thickness of the overhang portion 434 formed by the tungsten layer during operation 320 .

[0070] In one embodiment, which may be combined with other embodiments, where operation 340 is performed, the second process is purged before proceeding to operation 350 .

[0071] At operation 350, the substrate is exposed to a nitrogen plasma suppression process. Figure 4D The nitrogen plasma suppression treatment process of operation 350 utilizes ion-based and / or radical-based nitrogen plasma to achieve conformal treatment by forming a nitrogen passivation layer 454 along the upper surface 420u or field region, overhang 434, and along the sidewall surface 422s inside the feature 422, while leaving the bottom surface 422b substantially uncoated. In one embodiment that may be combined with other embodiments, such as Figure 4D As shown, the passivation layer 454 coats the nucleation layer 440. The nitrogen passivation layer 454 inhibits the growth of subsequently deposited metal fill material along the passivation region (e.g., the upper surface 420u, the overhang 434, and / or the sidewall surface 422s), while enabling bottom-up growth of the nucleation layer 440 or the tungsten liner 430 (if the nucleation layer 440 is not present) formed above the bottom surface 422b. The passivation layer 454 can be formed along a portion of the length (corresponding to the depth "D1") of the sidewall surface 422s.

[0072] In one embodiment that may be combined with other embodiments, the nitrogen plasma suppression treatment process of operation 350 may include exposing a portion of the bottom layer (e.g., one of the tungsten liner 430 and / or the nucleation layer 440) to the nitrogen plasma suppression treatment process. During operation 350, the substrate is exposed to an activated species of a process gas, such as nitrogen process radicals from a remote plasma source. Suitable process gases that may be used for the nitrogen plasma suppression process include N2, H2, NH3, NH4, O2, CH4, NO, NO2, N2H4, NF3, or a combination thereof. In one embodiment that may be combined with other embodiments, the process gas includes nitrogen, such as N2, N2 / H2, NH3, NH4, NO, NO2, N2H4, NF3, or a combination thereof, and the activated species includes nitrogen radicals, such as atomic nitrogen. The process gas may further include an inert gas, such as argon (Ar), helium (He), krypton (Kr), or a combination thereof. In a specific embodiment, the process gas includes argon (Ar) and nitrogen (N2).

[0073] In one embodiment that may be combined with other embodiments, the nitrogen plasma suppression treatment process is an inductively coupled plasma process. In one embodiment that may be combined with other embodiments, the nitrogen plasma suppression treatment process is a capacitively coupled plasma process. In one embodiment that may be combined with other embodiments, the nitrogen plasma is formed in a remote plasma source (RPS). In one embodiment that may be combined with other embodiments, the nitrogen plasma is generated in the processing region 221 (e.g., direct plasma). In one embodiment that may be combined with other embodiments, the nitrogen plasma suppression treatment process includes exposing the bottom layer 246 to a plasma formed by a processing gas including a nitrogen-containing gas. In one embodiment that may be combined with other embodiments, the plasma treatment process includes exposing the nucleation layer to free radicals from an ICP plasma formed by a processing gas including a nitrogen-containing gas (e.g., N2) and an inert gas (e.g., Ar). In one embodiment that may be combined with other embodiments, the plasma treatment process may include exposing the bottom layer to a plasma formed in the RPS to form a processing gas including one or more of N2 and Ar. In one embodiment, which may be combined with other embodiments, the nitrogen plasma suppression treatment process may include exposing the nucleation layer to a plasma including a plurality of radicals (nitrogen radicals) or a plurality of ions (nitrogen ions).

[0074] Without intending to be bound by theory, it is generally believed that the activated nitrogen species formed during the treatment with free radicals are incorporated into portions of the nucleation layer 440 (if present) or portions of the tungsten liner 430 (if the nucleation layer 440 is not present) by adsorbing the activated nitrogen species and / or by reacting with the metallic tungsten of the nucleation layer 440 or tungsten liner 430 to form a tungsten nitride (WN) surface, referred to as a nitrogen passivation layer 454. The adsorbed nitrogen and / or nitrided surface of the tungsten liner 430 or nucleation layer 440 desirably retards (inhibits) further tungsten nucleation and thus subsequent tungsten deposition thereon.

[0075] See also FIG. 2A to FIG. 2B In one embodiment that may be combined with other embodiments, exposing the bottom layer 446 to processing radicals includes forming a processing plasma 282A of a substantially halogen-free processing gas mixture using a first radical generator 206A, and flowing effluent of the processing plasma 282A into the processing region 221. In one embodiment, which may be combined with other embodiments, the flow rate of the process gas mixture into the first radical generator 206A, and thus the flow rate of the process plasma effluent (such as nitrogen) into the process region 221, is between about 1 sccm and about 3000 sccm, such as between about 1 sccm and about 2500 sccm, such as between about 1 sccm and about 2000 sccm, such as between about 1 sccm and about 1000 sccm, such as between about 1 sccm and about 500 sccm, such as between about 1 sccm and about 300 sccm, such as between about 1 sccm and about 100 sccm, such as between about 1 sccm and about 75 sccm, such as between about 1 sccm and about 50 sccm.

[0076] In one embodiment, which may be combined with other embodiments, the inhibition treatment process includes exposing the semiconductor device structure 400 to treatment radicals for a period of about 2 seconds or more, such as about 2 seconds to about 30 seconds, such as about 5 seconds to about 20 seconds, such as about 5 seconds to about 10 seconds.

[0077] In one embodiment that can be combined with other embodiments, the concentration of the substantially halogen-free process gas in the process gas mixture is about 0.1 space % to about 50 space %, such as about 0.2 space % to about 40 space %, about 0.2 space % to about 30 space %, about 0.2 space % and about 20 space %, or for example, such as about 0.2 space % and about 10 space %, such as about 0.2 space % and about 5 space %. The remainder of the process gas mixture can be an inert gas. The inert gas can be, for example, argon (Ar), helium (He), krypton (Kr), or the like. In one embodiment that can be combined with other embodiments, the process gas includes nitrogen (N2) and argon (Ar). In one embodiment that can be combined with other embodiments, the process gas consists only of nitrogen (N2) and argon (Ar). In one embodiment that can be combined with other embodiments, the process gas can be mainly composed of nitrogen (N2) and argon (Ar) or can be substantially composed of nitrogen (N2) and argon (Ar).

[0078] See also FIG. 2A to FIG. 2B In other embodiments, the process radicals may be formed using a remote plasma source (not shown) that is ignited and maintained separate from the process region 221 by the showerhead 218, such as between the showerhead 218 and the cover plate 216. In those embodiments, the activated process gas may flow through an ion filter to remove substantially all ions from the process radicals before they reach the process region 221 and the surface of the semiconductor device structure 400. In one embodiment that may be combined with other embodiments, the showerhead 218 may be used as an ion filter. In other embodiments, the plasma used to form the process radicals is an in-situ plasma formed in the process region 221 between the showerhead 218 and the semiconductor device structure 400. In one embodiment that may be combined with other embodiments, for example, when an in-situ process plasma is used, the semiconductor device structure 400 may be biased to control the directionality and / or accelerate ions formed by the process gas, such as charged process radicals, toward the substrate surface. In other embodiments, the semiconductor device structure 400 is exposed to the activated species without biasing the semiconductor device structure 400 in an unbiased process.

[0079] In one embodiment that can be combined with other embodiments, the semiconductor device structure 400 can be heated before or during the nitrogen plasma suppression treatment process of operation 350. For example, heating the semiconductor device structure 400 at a temperature of at least about 250 degrees Celsius, or at least about 350 degrees Celsius can promote the effectiveness of the nitrogen plasma suppression treatment of the bottom layer 246. In one embodiment that can be combined with other embodiments, the substrate can be heated at a temperature from about 250 degrees Celsius to about 550 degrees Celsius, or at a temperature in a range from about 350 degrees Celsius to about 450 degrees Celsius. The actual maximum substrate temperature can vary based on hardware limitations and / or the thermal budget of the substrate being processed.

[0080] In one embodiment, which may be combined with other embodiments, the inhibition treatment process includes maintaining the process region 221 at a pressure of less than about 100 Torr while flowing the activated process gas therein. For example, during the inhibition treatment process, the process region 221 may be maintained at a pressure of about 20 Torr or less, or in a range from about 100 mTorr to about 10 Torr, or in a range from about 0.5 Torr to about 10 Torr, or in a range from about 0.5 Torr to about 5 Torr, or in a range from about 1 Torr to about 5 Torr.

[0081] At operation 360, a tungsten gap fill material 464 is deposited at least partially onto the substrate via a bottom-up metal fill process. Figure 4E In one embodiment that can be combined with other embodiments, the bottom-up tungsten filling process can completely fill the feature 422, such as Figure 4G shown.

[0082] In other embodiments, the bottom-up metal filling process may partially fill the feature 422 at operation 370, and then Figure 4E The nitrogen plasma suppression process shown in operation 380 is as follows. Figure 4F As shown. The nitrogen plasma suppression treatment process at operation 380 may be performed similarly to the nitrogen plasma suppression treatment process at operation 350. In one embodiment that may be combined with other embodiments, the nitrogen passivation layer 454 formed during operation 350 may dissipate after a certain amount of time. The nitrogen plasma suppression treatment process at operation 380 re-forms the nitrogen passivation layer 454 on the sidewall surface 422s, the overhang portion 434, and the upper surface 420u or the exposed surface above the field region, such as Figure 4E As shown. At operation 380, the nitrogen passivation layer is reformed so that the bottom-up tungsten fill can continue with the tungsten gap fill material 464. Operations 370 and 380 may be repeated until the feature 422 is filled to the target level, as shown. Figure 4G shown.

[0083] In one embodiment that may be combined with other embodiments, the tungsten gap fill material 464 is formed using a CVD process, including concurrently flowing (co-flowing) a tungsten-containing precursor gas and a reducing agent into a processing region and exposing the semiconductor device structure 400 to the tungsten-containing precursor gas and the reducing agent. The tungsten-containing precursor and the reducing agent used for the tungsten gap fill CVD process may include any combination of the tungsten-containing precursor and the reducing agent described herein. In one embodiment that may be combined with other embodiments, the tungsten-containing precursor includes WF6, and the reducing agent includes hydrogen. In one embodiment that may be combined with other embodiments, the tungsten gap fill material 464 partially fills the feature 422.

[0084] In one embodiment, which may be combined with other embodiments, the tungsten-containing precursor flows into the processing region 221 at a flow rate in a range from about 10 sccm to about 1200 sccm, or greater than about 50 sccm, or less than about 1000 sccm, or in a range from about 100 sccm to about 900 sccm. The reducing agent flows into the processing region 221 at a rate greater than about 500 sccm, such as greater than about 750 sccm, greater than about 1000 sccm, or in a range from about 500 sccm to about 10000 sccm, such as in a range from about 1000 sccm to about 9000 sccm, or in a range from about 1000 sccm to about 8000 sccm.

[0085] In one embodiment that can be combined with other embodiments, the tungsten gapfill CVD process conditions are selected to provide a tungsten feature with relatively low residual film stress when compared to conventional tungsten CVD processes. For example, in one embodiment that can be combined with other embodiments, the tungsten gapfill CVD process includes heating the substrate at a temperature of about 250°C or greater, such as about 300°C or greater, or in a range from about 250°C to about 500°C, or in a range from about 350 degrees Celsius to about 450 degrees Celsius. During the CVD process, the processing region 221 can be maintained at a pressure of less than about 500 Torr, less than about 600 Torr, less than about 500 Torr, less than about 400 Torr, or in a range from about 1 Torr to about 500 Torr, such as in a range from about 1 Torr to about 450 Torr, or in a range from about 1 Torr to about 400 Torr, or for example in a range from about 1 Torr to about 300 Torr.

[0086] In one embodiment, which may be combined with other embodiments, operation 350 is performed at a low pressure in a range from about 0.1 mTorr to about 5 Torr and operation 360 is performed at a higher pressure in a range from about 10 Torr to about 300 Torr.

[0087] In another embodiment, the tungsten gapfill material 464 is deposited using an atomic layer deposition (ALD) process at operation 360. The tungsten gapfill ALD process includes repeated cycles of alternately exposing the semiconductor device structure 400 to a tungsten-containing precursor gas and a reducing agent and purging the processing region 221 between the alternating exposures.

[0088] The tungsten-containing precursor and the reducing agent are each flowed into the processing region 221 for a duration between about 0.1 seconds and about 10 seconds, such as between about 0.5 seconds and about 5 seconds. The processing region 221 can be purged between alternating exposures by flowing an inert purge gas, such as argon (Ar) or hydrogen, into the processing region 221 for a duration in a range from about 0.1 seconds to about 10 seconds, such as in a range from about 0.5 seconds to about 5 seconds.

[0089] In other embodiments, the tungsten gapfill material 464 is deposited using a pulsed CVD method that includes repeated cycles of alternately exposing the semiconductor device structure 400 to a tungsten-containing precursor gas and a reducing agent without purging the process region 221. The processing conditions of the pulsed CVD process for the tungsten gapfill may be the same, substantially the same, or within the same range as those described above for the tungsten gapfill ALD process.

[0090] After operation 380, the semiconductor device structure 400 may be exposed to additional processing. In one embodiment that may be combined with other embodiments, the additional processing includes a planarization process, for example, a chemical mechanical polishing (CMP) process or an etch back process may be performed to remove excess or additional burden of the conductive material (if present) on the upper surface 420u of the dielectric layer 420. After the planarization process is completed, the top surface 484 of the tungsten gap fill material 464 may be coplanar or flush with the upper surface 420u of the dielectric layer and the top surfaces of the nucleation layer 440 and the tungsten liner 430, as shown in FIG. Figure 4H shown.

[0091] In one embodiment that can be combined with other embodiments, Figure 4H As shown, one or more tungsten layers 430, nucleation layer 440, and tungsten gap fill material 464 are monolithic and have no interface therebetween. Tungsten gap fill material 464, tungsten liner 430, and / or nucleation layer 440 together form a tungsten gap fill layer or tungsten containing layer.

[0092] See also Figure 3B, method 300B depicts another sequence of operations. Method 300B is similar to method 300A, except that method 300B omits the nucleation layer formed during operation 340. Therefore, during method 300B, the nitrogen plasma suppression treatment process of operation 350 is performed directly on the tungsten liner layer formed during operation 330.

[0093] See also Figure 3C , method 300C depicts another sequence of operations. Method 300C is similar to method 300A, except that method 300C includes an additional nitrogen plasma suppression treatment process of operation 350 performed after operation 330 and before operation 340. Therefore, during method 300C, the nitrogen plasma suppression treatment process of operation 350 is performed directly on the tungsten liner layer formed during operation 330 and also directly on the nucleation layer formed during operation 340.

[0094] Embodiments may include one or more of the following potential advantages. Various embodiments described herein illustrate an integrated solution for a PVD tungsten liner, followed by a nitrogen plasma suppression process, followed by a CVD tungsten fill, which enables seamless via filling in very small structures, for example, via sizes less than 15 nanometers. Various embodiments eliminate high resistivity layers, for example, TiN barrier layers, nucleation layers, and tungsten oxide formed during vacuum breakdown. Eliminating these high resistivity layers improves component resistivity by approximately 30%. In addition, the reduction of tungsten oxide helps reduce CMP defects. Various embodiments enable the nitrogen plasma suppression process to be performed directly on the PVD tungsten liner, which helps achieve seamless tungsten gap filling.

[0095] In the Summary of the Invention and the Detailed Description, as well as in the Claims and the Drawings, reference is made to specific features (including method operations) of the present disclosure. It will be understood that the disclosure in this specification includes all possible combinations of such specific features. For example, where a specific feature is disclosed in the context of a specific aspect or embodiment of the present disclosure or a specific claim, that feature may also be used in combination with and / or in the context of other specific aspects and embodiments of the present disclosure to the extent possible, and is generally used in the present disclosure.

[0096] In this specification, when a range is given as "(first number) to (second number)" or "(first number)-(second number)", this means a range whose lower limit is the first number and whose upper limit is the second number. For example, 25 to 100 mm means a range whose lower limit is 25 mm and whose upper limit is 100 mm.

[0097] The embodiments and all functional operations described in this specification may be implemented in digital electronic circuit systems, or in computer software, firmware, or hardware, including the structural components disclosed in this specification and their structural equivalents, or a combination thereof. The embodiments described herein may be implemented as one or more non-transitory computer program products, that is, one or more computer programs tangibly embodied in a machine-readable storage device, for execution by a data processing device, or for controlling the operation of a data processing device, such as a programmable processor, a computer, or multiple processors or computers.

[0098] The processes and logic flows described in this specification can be performed by one or more programmable processors executing one or more computer programs to perform functions by operating on input data and generating output. The processes and logic flows can also be performed by special purpose logic circuits, and the apparatus can also be implemented as a special purpose logic circuit system, such as an FPGA (field programmable gate array) or an ASIC (application specific integrated circuit).

[0099] The term "data processing apparatus" encompasses all devices, elements and machines for processing data, including by way of example a programmable processor, a computer, or multiple processors or computers. In addition to hardware, the apparatus may include code that establishes an execution environment for the computer program in question, for example, code constituting processor firmware, a protocol stack, a database management system, an operating system, or a combination of one or more of the same. Processors suitable for executing computer programs include by way of example general and special purpose microprocessors, and any one or more processors of any kind of digital computer.

[0100] Computer readable media suitable for storing computer program instructions and data include all forms of nonvolatile memory, media and memory elements, including by way of example semiconductor memory elements such as EPROM, EEPROM, and flash memory elements; magnetic disks, such as internal hard disks or removable disks; magneto-optical disks; and CD ROM and DVD-ROM disks. The processor and memory may be supplemented by, or integrated into, special purpose logic circuitry.

[0101] The terms "comprising", "including", and "having" and their grammatical equivalents are used herein to mean that other components, ingredients, operations, etc. are present as appropriate. For example, the word "comprising" (or "which comprises") components A, B, and C may consist of components A, B, and C (i.e., only contain components A, B, and C), or may contain not only components A, B, and C, but also one or more other components. In addition, whenever a composition, element, or group of elements is preceded by the transitional phrase "comprising" or its grammatical equivalent, it will be understood that the same composition or group of elements may also be preceded by the transitional phrase "consisting essentially of", "consisting of", "selected from the group consisting of", or "is" before the description of the composition, element, or multiple elements, and vice versa.

[0102] Where reference is made herein to a method comprising two or more defined operations, the defined operations may be performed in any order or concurrently (unless the context excludes that possibility), and the method may include one or more other operations performed before any defined operation, between the defined operations, or after all of the defined operations (unless the context excludes that possibility).

[0103] When introducing elements of the present disclosure or exemplary aspects or embodiments thereof, the articles "a," "an," "the," and "said" are intended to mean that there are one or more of those elements.

[0104] While the foregoing is directed to embodiments of the present disclosure, other and further embodiments of the disclosure may be devised without departing from the basic scope thereof, and the scope thereof is to be determined by the claims that follow.

Claims

1. A method for processing a semiconductor device structure, comprising the following steps: exposing at least one feature formed in the substrate to a physical vapor deposition (PVD) process to deposit a tungsten liner layer over the at least one feature, wherein the PVD process is performed in a first processing region of a first processing chamber and the at least one feature is defined by sidewall surfaces and a bottom surface extending between the sidewall surfaces; transferring the substrate from the first processing region of the first processing chamber to a second processing region of a second processing chamber without breaking vacuum; exposing the tungsten liner layer to nitrogen-containing radicals in the second processing region to passivate exposed portions of the tungsten liner layer, wherein the tungsten liner layer formed along the bottom surface remains substantially unpassivated; as well as Exposing the feature to a tungsten-containing precursor gas to form a tungsten fill layer over the tungsten liner layer within the at least one feature in the second processing region includes preferentially growing the tungsten fill layer from the tungsten liner layer formed along the bottom surface.

2. The method of claim 1, wherein exposing the feature to the tungsten-containing precursor gas to form the tungsten fill layer over the tungsten liner layer comprises a chemical vapor deposition (CVD) process.

3. The method of claim 1 , wherein the step of exposing the tungsten liner layer to nitrogen-containing radicals in the second processing region comprises the following steps: generating a plasma comprising nitrogen-containing radicals in a remote plasma source (RPS), wherein the plasma is formed from a process gas comprising nitrogen and an inert gas; and The nitrogen-containing radicals are flowed into the second processing region of the second processing chamber in which the substrate is disposed.

4. The method of claim 3, further comprising the step of flowing the plasma containing the nitrogen-containing radicals through an ion filter to remove substantially all ions from the plasma prior to flowing the nitrogen-containing radicals into the second processing region.

5. The method of claim 4, wherein the process gas comprises from about 5% to about 20% nitrogen and argon.

6. The method of claim 1 , further comprising the steps of alternatingly exposing the tungsten liner layer to nitrogen-containing radicals in the second processing region to passivate the exposed portion of the tungsten liner layer and exposing the feature to the tungsten-containing precursor gas to form the tungsten fill layer over the tungsten liner layer.

7. A method for processing a semiconductor device structure, comprising the following steps: exposing at least one feature formed in the substrate to a physical vapor deposition (PVD) process to deposit a tungsten liner layer over the at least one feature, wherein the PVD process is performed in a first processing region of a first processing chamber and the at least one feature is defined by sidewall surfaces and a bottom surface extending between the sidewall surfaces; transferring the substrate from the first processing region of the first processing chamber to a second processing region of a second processing chamber without breaking vacuum; exposing the tungsten liner layer to a first tungsten-containing precursor and a reducing agent to form a boron-tungsten nucleation layer over the tungsten liner layer in the second processing region; exposing the boron-tungsten nucleation layer to nitrogen-containing radicals in the second treatment region to passivate exposed portions of the boron-tungsten nucleation layer; as well as The feature is exposed to a second tungsten-containing precursor gas to form a tungsten fill layer over the boron-tungsten nucleation layer within the at least one feature in the second processing region.

8. The method of claim 7, wherein exposing the feature to the second tungsten-containing precursor gas to form the tungsten fill layer over the tungsten liner layer comprises a chemical vapor deposition (CVD) process.

9. The method of claim 7, wherein the step of exposing the boron-tungsten nucleation layer to nitrogen-containing radicals in the second processing region comprises the steps of: generating a plasma comprising nitrogen-containing radicals in a remote plasma source (RPS), wherein the plasma is formed from a process gas comprising nitrogen and an inert gas; and The nitrogen-containing radicals are flowed into the second processing region of the second processing chamber in which the substrate is disposed.

10. The method of claim 9, further comprising the step of flowing the plasma containing the nitrogen-containing radicals through an ion filter to remove substantially all ions from the plasma prior to flowing the nitrogen-containing radicals into the second processing region.

11. The method of claim 10, wherein the process gas comprises from about 5% to about 20% nitrogen and the remainder being the inert gas, the inert gas being argon.

12. The method of claim 7, further comprising the steps of alternatingly exposing the boron-tungsten nucleation layer to nitrogen-containing radicals in the second processing region to passivate the exposed portion of the tungsten liner layer and exposing the feature to the second tungsten-containing precursor gas to form the tungsten fill layer above the tungsten liner layer.

13. The method of claim 7, wherein exposing the tungsten liner layer to the first tungsten-containing precursor and the reducing agent comprises alternating repeated cycles of exposing the tungsten liner layer to the first tungsten-containing precursor and the reducing agent.

14. The method of claim 13, wherein the first tungsten-containing precursor is WF6 and the reducing agent is B2H6.

15. A method for processing a semiconductor device structure, comprising the following steps: exposing a top opening of a feature formed in a substrate to a physical vapor deposition (PVD) process to deposit a tungsten liner layer within the feature, wherein the PVD process is performed in a first processing region of a first processing chamber and the tungsten liner layer forms an overhang that partially obstructs the top opening of the feature; transferring the substrate from the first processing region of the first processing chamber to a second processing region of a second processing chamber without breaking vacuum; exposing the overhang to nitrogen-containing radicals in the second processing region to inhibit subsequent growth of tungsten along the overhang; and The feature is exposed to a tungsten-containing precursor gas to form a tungsten fill layer over the tungsten liner layer within the feature in the second processing region.

16. The method of claim 15, wherein exposing the feature to the tungsten-containing precursor gas to form the tungsten fill layer over the tungsten liner layer comprises a chemical vapor deposition (CVD) process.

17. The method of claim 15, wherein the step of exposing the tungsten liner layer to nitrogen-containing radicals in the second processing region comprises the steps of: generating a plasma comprising nitrogen-containing radicals in a remote plasma source (RPS), wherein the plasma is formed from a process gas comprising nitrogen and an inert gas; and The nitrogen-containing radicals are flowed into the second processing region of the second processing chamber in which the substrate is disposed.

18. The method of claim 17, further comprising the step of flowing the plasma containing the nitrogen-containing radicals through an ion filter to remove substantially all ions from the plasma prior to flowing the nitrogen-containing radicals into the second processing region.

19. The method of claim 18, wherein the process gas comprises from about 5% to about 20% nitrogen and the remainder being the inert gas, the inert gas being argon.

20. The method of claim 15, further comprising the steps of alternating exposing the tungsten liner layer to nitrogen-containing radicals in the second processing region to passivate exposed portions of the tungsten liner layer and exposing the feature to the tungsten-containing precursor gas to form the tungsten fill layer over the tungsten liner layer.

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