Modification of carbon films in a plasma chamber

Abstract

Methods and apparatuses are provided for depositing high density carbon-containing material in a plasma environment using a co-flowed doping gas and plasma during deposition, or by alternating between depositing and physical sputtering using plasma periodically while depositing carboncontaining material, or by using a combination of both.

Description

MODIFICATION OF CARBON FILMS IN A PLASMA CHAMBERINCORPORATION BY REFERENCE

[0000] A PCT Request Form is filed concurrently with this specification as part of the present application. Each application that the present application claims benefit of or priority to as identified in the concurrently filed PCT Request Form is incorporated by reference herein in its entirety and for all purposes.BACKGROUND

[0001] Semiconductor fabrication processes often involve forming carbon-containing material to be used as a mask. However, as devices shrink, and technology advances, it is challenging to form high quality carbon-containing materials with high density and low roughness.

[0002] The background description provided herein is for the purposes of generally presenting the context of the disclosure. Work of the presently named inventors, to the extent it is described in this background section, as well as aspects of the description that may not otherwise qualify as prior art at the time of filing, are neither expressly nor impliedly admitted as prior art against the present disclosure.SUMMARY

[0003] One aspect involves a method for processing substrates, the method including: providing a substrate to a process chamber; exposing the substrate to a carbon-containing precursor to deposit a partial layer of a carbon-containing material onto a substrate surface to a thickness sufficient to achieve growth of the carbon-containing material without forming columnar growth of the carbon- containing material on the substrate surface; exposing the partial layer of the carbon-containing material to a sputtering gas in a plasma environment; and repeating exposing the substrate to the carbon-containing precursor and exposing partially deposited carbon-containing material to the sputtering gas in the plasma environment in cycles.

[0004] In various embodiments, the method also includes co-flowing a doping gas with the carbon-containing precursor to the process chamber when depositing the partial layer of the carbon-containing material.

[0005] In various embodiments, a second plasma is ignited when exposing the substrate to the carbon-containing precursor to deposit the carbon-containing material by plasma enhanced chemical vapor deposition.

[0006] In some embodiments, the sputtering gas is selected from the group consisting of argon, krypton, xenon, radon, and combinations thereof.

[0007] In some embodiments, the method also includes flowing a carrier gas with the sputtering gas. For example, in some embodiments, the carrier gas is selected from the group consisting of nitrogen gas, helium, and combinations thereof.

[0008] In some embodiments, the plasma environment is generated using a dual frequency plasma. In various embodiments, the plasma is generated in situ.

[0009] In some embodiments, the substrate is heated to a temperature of about 550°C to about 650°C.

[0010] In some embodiments, the doping gas is a hydrogen-containing gas.

[0011] In some embodiments, the doping gas is a fluorine-containing gas.

[0012] In some embodiments, the doping gas is selected from the group consisting of silane (SitU), diborane (B2H6), boron trifluoride (BF3), sulfur hexafluoride (SFe), tungsten pentafluoride (WF5), tungsten hexafluoride (WFe), and combinations thereof.

[0013] In some embodiments, the doping gas is delivered in a plasma environment.

[0014] In some embodiments, the plasma environment is generated using a dual frequency plasma.

[0015] Another aspect involves a method for processing substrates, the method including: providing a substrate to a process chamber; introducing a carbon-containing precursor to the process chamber to deposit a partial layer of a carbon-containing material onto a substrate surface; and co-flowing a doping gas with the carbon-containing precursor to the process chamber when depositing the partial layer of the carbon-containing material.

[0016] In various embodiments, the method also includes stopping flow of the carbon- containing precursor and the doping gas after the partial layer of the carbon-containing material is deposited to a thickness sufficient to achieve growth of the carbon-containing material without forming columnar growth of the carbon-containing material on the substrate surface and introducing a sputtering gas in a plasma environment to partially etch the partial layer of the carbon-containing material.

[0017] In various embodiments, the method also includes alternating between the depositing and the introducing of the sputtering gas.

[0018] In various embodiments, a second plasma is ignited when introducing the carbon- containing precursor to the process chamber to deposit the partial layer of the carbon-containing material onto the substrate surface.

[0019] In some embodiments, the sputtering gas is selected from the group consisting of argon, krypton, xenon, radon, and combinations thereof.

[0020] In some embodiments, the method also includes flowing a carrier gas with the sputtering gas. For example, in some embodiments, the carrier gas is selected from the group consisting of nitrogen gas, helium, and combinations thereof.

[0021] In some embodiments, the plasma environment is generated using a dual frequency plasma. In various embodiments, the plasma is generated in situ.

[0022] In some embodiments, the substrate is heated to a temperature of about 550°C to about 650°C.

[0023] In some embodiments, the doping gas is a hydrogen-containing gas.

[0024] In some embodiments, the doping gas is a fluorine-containing gas.

[0025] In some embodiments, the doping gas is selected from the group consisting of silane (Si H4), diborane (B2H6), boron trifluoride (BF3), sulfur hexafluoride (SFe), tungsten pentafluoride (WFs), tungsten hexafluoride (WFe), and combinations thereof.

[0026] In some embodiments, the doping gas is delivered in a plasma environment.

[0027] In some embodiments, the plasma environment is generated using a dual frequency plasma.

[0028] In various embodiments, the sputtering gas causes generation of ions.

[0029] In various embodiments, the carbon-containing material is not amorphous carbon.

[0030] In various embodiments, the carbon-containing material ha s a density of greater than 2.0 g / cc.

[0031] Another aspect involves an apparatus for processing substrates, the apparatus including: one or more process chambers, each process chamber including a chuck; one or more gas inlets into the process chambers and associated flow-control hardware; a plasma generator; and a controller having at least one processor and a memory, whereby the at least one processor and the memory are communicatively connected with one another, the at least one processor is at least operatively connected with the flow-control hardware, and the memory stores computerexecutable instructions for controlling the at least one processor to at least control the flow-control hardware to: cause introduction of a carbon-containing precursor to the one or more process chamber for a duration sufficient to deposit a partial layer of a carbon-containing material onto a substrate surface to a thickness sufficient to achieve growth of the carbon-containing material without forming columnar growth of the carbon-containing material on the substrate surface; cause stopping of the introduction of the carbon-containing precursor prior to introduction of a sputtering gas and generation of a plasma; and cause repeating of the introduction of the carbon-containing precursor and the introduction of the sputtering gas and generation of the plasma in cycles.

[0032] In various embodiments, the controller also includes instructions to cause co-flowing of a doping gas with the carbon-containing precursor to the process chamber.

[0033] In various embodiments, the controller further includes instructions for causing alternating between the depositing and the introducing of the sputtering gas.

[0034] In various embodiments, electrodes for generating a plasma are set apart in gap having a gap distance of about 0.25 inches to about 0.4 inches.

[0035] Another aspect involves an apparatus for processing substrates, the apparatus including:one or more process chambers, each process chamber including a chuck; one or more gas inlets into the process chambers and associated flow-control hardware; a plasma generator; and a controller having at least one processor and a memory, whereby the at least one processor and the memory are communicatively connected with one another, the at least one processor is at least operatively connected with the flow-control hardware, and the memory stores computerexecutable instructions for controlling the at least one processor to at least control the flow-control hardware to: cause introduction of a carbon-containing precursor to the process chamber to deposit a partial layer of a carbon-containing material onto a substrate surface; and cause co-flowing of a doping gas with the carbon-containing precursor to the process chamber when depositing the partial layer of the carbon-containing material.

[0036] In various embodiments, the controller also includes instructions to cause stopping of the flow of the carbon-containing precursor and the doping gas after the partial layer of the carbon- containing layer is deposited to a thickness sufficient to deposit a partial layer of a carbon- containing material onto a substrate surface to a thickness sufficient to achieve growth of the carbon-containing material without forming columnar growth of the carbon-containing material on the substrate surface and cause introduction of a sputtering gas and generation of a plasma.

[0037] In various embodiments, the controller further includes instructions for causing alternating between the depositing and the introducing of the sputtering gas.

[0038] In various embodiments, electrodes for generating a plasma are set apart in gap having a gap distance of about 0.25 inches to about 0.4 inches.

[0039] These and other aspects are described further below with reference to the drawings.BRIEF DESCRIPTION OF THE DRAWINGS

[0040] Figure 1A is a process flow diagram depicting operations for a method performed in accordance with certain disclosed embodiments.

[0041] Figure IB is a process flow diagram depicting operations for a method performed in accordance with certain disclosed embodiments.

[0042] Figure 1C is a process flow diagram depicting operations for a method performed in accordance with certain disclosed embodiments.

[0043] Figure 2 is a schematic diagram of an example process chamber for performing certain disclosed embodiments.

[0044] Figure 3 is a schematic diagram of an example tool for performing certain disclosed embodiments.

[0045] Figure 4 is a schematic diagram of an example tool for performing certain disclosed embodiments.DETAILED DESCRIPTION

[0046] In the following description, numerous specific details are set forth to provide a thorough understanding of the presented embodiments. The disclosed embodiments may be practiced without some or all of these specific details. In other instances, well-known process operations have not been described in detail to not unnecessarily obscure the disclosed embodiments. While the disclosed embodiments will be described in conjunction with the specific embodiments, it will be understood that it is not intended to limit the disclosed embodiments.

[0047] Semiconductor fabrication processes involve fabrication of memory and logic devices. Examples include 3D-NAND and dynamic random-access memory (DRAM) applications, as well as logic applications for mid end of line (MEOL) and back end of line (BEOL) processes. Fabrication of memory and logic devices often involve etching features, such as contact holes, on a substrate, which may include one material or multiple layers of material some of which may be semiconductor material. Some fabrication methods of semiconductor devices involve using a carbon-containing hard mask (which may be referred to herein as an “ashable hardmask” or “AHM’') as a mask for etching other layers on the substrate.

[0048] AHMs have a chemical composition that allows them to be removed by a technique referred to as “ashing,” “plasma ashing,” or “dry stripping” once they have served their purpose. One example of an AHM is an amorphous carbon layer or film. An AHM is generally composed of carbon and hydrogen with, optionally, a trace amount of one or more dopants (e.g., nitrogen, fluorine, boron, and silicon). The bonding structure of an AHM can vary from sp2(graphite-like) or sp3(diamond-like), or a combination of both, depending on the deposition conditions.

[0049] While the mask may be, in some cases, sacrificial, certain properties of the mask assist in achieving high quality etching of underlayers in the substrate and thereby affects device performance. In some cases, an AHM may be deposited at high temperatures (such as at least about 550°C, or at least about 650°C) by plasma-enhanced chemical vapor deposition (PECVD) and such films may have a density of about 2 g / cc. However, when certain deposition techniques are used to deposit AHMs by PECVD to achieve a density of greater than 2 g / cc, roughness appears on the deposited film, which may be due to conical growth at nucleation sites, resulting in bulbousshaped surface roughness of the film. The roughness of such films may exceed at least about 2.5 nm Rq or at least about 5 nm Rq.

[0050] AHMs may be referred to herein as “carbon-containing material.” It will be understood that “carbon-containing material” includes AHMs, as well as other carbon-containing materials, or diamond-like carbon, or amorphous carbon, or carbon.

[0051] Provided herein are methods and apparatuses for depositing carbon-containing hard masks using PECVD with greater than 2 g / cc density and reduced surface roughness. Methodsinvolve depositing the hard mask using a dopant, or performing an etching treatment, or both.

[0052] Figure 1A provides an example process flow diagram depicting operations that may be performed in accordance with certain disclosed embodiments. In an operation 102, a substrate is provided to a process chamber. The substrate may include a partially fabricated semiconductor structure on it. The substrate may be a silicon wafer, e.g., a 200-mm wafer, a 300-mm wafer, or a 450-mm wafer, including wafers having one or more layers of material, such as dielectric, conducting, or semi-conducting material deposited thereon. In various embodiments, the substrate is patterned. In various embodiments, multiple features are present on the substrate. The feature may be a via or hole or trench previously etched in a dielectric material. The feature may be previously etched down to a metal layer such that the bottom of the feature includes exposed metal. A via, trench or other recessed feature may be referred to as an unfilled feature or a feature. According to various embodiments, the feature profile may narrow gradually and / or include an overhang at the feature opening. A re-entrant profile is one that narrows from the bottom, closed end, or interior of the feature to the feature opening. A re-entrant profile may be generated by asymmetric etching kinetics during patterning and / or the overhang due to non-conformal film step coverage in the previous film deposition, such as deposition of a diffusion barrier. In various examples, the feature may have a width smaller in the opening at the top of the feature than the width of the bottom of the feature.

[0053] In an operation 104, the substrate is exposed to a carbon-containing precursor to deposit a partial layer of a carbon-containing material onto a surface of the substrate. In embodiments described herein, a “partial” layer of a carbon-containing material refers to a portion of a layer, or any layer of a carbon-containing material during the deposition of the carbon-containing material prior to completing deposition of the carbon-containing material; that is, formation of a “partial” layer of the carbon-containing material suggests that additional carbon-containing material may be deposited after the “partial” layer is deposited.

[0054] During this operation, the carbon-containing precursor may be any suitable precursor containing at least one carbon atom. In some embodiments, the carbon-containing precursor is a hydrocarbon precursor. A hydrocarbon precursor may have the chemical formula CxHy, where x is an integer from 2 to 10 and y is an integer from 2 to 24. Examples include methane, acetylene, ethylene, propylene, butane, cyclohexane, benzene, and toluene.

[0055] During operation 104, the carbon-containing precursor may be introduced in vapor or gas phase. In some embodiments, the carbon-containing precursor may be provided in a plasma environment.

[0056] Operation 104 is performed until the amount of carbon-containing material deposited is a thickness sufficient to achieve growth of the carbon-containing material without formingcolumnar growth of the carbon-containing material on the substrate surface. In some embodiments, the thickness is less than about 70 nm in thickness, or less than about 65 nm in thickness, or less than about 60 nm in thickness, or less than about 55 nm in thickness, or less than about 50 nm in thickness, or less than about 45 nm in thickness, or less than about 40 nm in thickness. At thickness of greater than about 80 nm, roughness and columnar growth of the carbon- containing material appears and may not be reversible.

[0057] In an operation 106, the partial layer of carbon-containing material is partially etched or sputtered to form an etched carbon-containing surface. Etching does not etch the entire amount of carbon-containing material already deposited on the substrate. Etching may only remove some nuclei sites on the surface of the carbon-containing material already deposited on the substrate. A small amount on the surface of the carbon-containing surface is sputtered in operation 106. Etching may be performed by physical sputtering. Etching is performed in a low-pressure environment. For example, the pressure may be less than about 2 Torr, or less than about 1 Torr, or about 0.5 Torr to about 1 Torr.

[0058] Etching is performed by delivering one or more sputtering gases, which may be any monatomic heavy molecule, such as argon, krypton, radon, and / or xenon, and generating a plasma using dual frequency plasma to generate a plasma etching species capable of sputtering the carbon surface of the etched carbon-containing surface. The sputtering gas may be flowed at a flow rate of at least about 10 slm, or about 5 slm to about 15 slm for a four-station chamber. Plasma is generated in-situ. In some embodiments, remote plasma may be used to generate the sputtering gas and may involve a negative biasing target substrate.

[0059] The sputtering gas may be delivered with a carrier gas, which in some cases may be diverted prior to delivery to the process chamber housing the substrate, or may be delivered into the chamber with the sputtering gas. The carrier gas may be nitrogen gas (N2) or helium gas or a mixture of both. The flow rate of the carrier gas may be about 5 slm to about 10 slm.

[0060] In some embodiments, sputtering is performed in the process chamber such that the distance between the electrodes (e.g., the electrode gap) is about 0.3 inches to about 0.5 inches.

[0061] The plasma is generated using a dual frequency plasma. The high frequency plasma may be set to a power of about 1 kW to about 9 kW or about 1 kW to about 5 kW for a four- station chamber. The low frequency plasma may be set to a power of about 1 kW to about 5 kW for a four-station chamber. In some embodiments, a single frequency low frequency plasma may be used instead.

[0062] During etching, the substrate temperature may be set to a high temperature, such as at least about 55O°C or at least about 600°C, or about 550°C to about 650°C.

[0063] In various embodiments, operations 106 and 104 are performed without breakingvacuum. In some embodiments, operations 106 and 104 are performed in the same chamber or in the same tool.

[0064] In an operation 108, the etched carbon-containing surface is exposed to a carbon- containing precursor to deposit additional carbon-containing material onto the etched carbon- containing surface. Deposition conditions for operation 108 may be the same as those in operation 104. Operations 106 and 108 may be optionally repeated in operation 120.

[0065] The process in Figure 1 A alternates between deposition and etching at a specific timing such that etching is performed every less than about 60 nm of deposition to inhibit formation of a pileus structure or columnar growth or microstructure formation of carbon while maintaining high density carbon deposition. Etching is performed prior to formation of microstructure formation of the carbon-containing material, which thereby prepares the surface for additional carbon- containing material growth that does not exhibit microstructure formation properties.

[0066] Additionally, in some embodiments, a doping gas may be used to facilitate improved density of the carbon-containing material. Figure IB provides an example process flow diagram depicting operations that may be performed in accordance with certain disclosed embodiments. In operation 102, a substrate is provided to a process chamber. This may be the same as operation 102 in Figure 1A.

[0067] During operation 104, the carbon-containing precursor may be introduced in vapor or gas phase. This may be the same as operation 104 in Figure 1A.

[0068] In an operation 110, a doping gas is co-flowed while exposing the substrate to the carbon- containing precursor to disrupt columnar growth and thus microstructure formation on the substrate surface. The doping gas is a hydrogen-containing gas that is capable of generating a hydrogen radical, and / or a fluorine-containing gas which can be capable of removing polymeric growth. Example doping gases include but are not limited to , diborane (B2H6), boron trifluoride (BF3), sulfur pentafluoride (SF5), sulfur hexafluoride (SFs), tungsten pentafluoride (WFs), and tungsten hexafluoride (WFe), silane (SiFU) and combinations thereof. Usage of a doping gas during deposition can improve smoothness and reduce roughness by reducing the likelihood of the carbon-containing material from forming columnar growth. In some embodiments, the flow rate of the doping gas is less than about 150 seem.

[0069] During deposition when using a doping gas, a plasma is used. The plasma may be a dual frequency plasma. The high frequency plasma may be generated at a power of about 2 kW to about 9 kW. The low frequency plasma may be generated at a power of about 3 kW to about 5kW. During deposition, the chamber pressure may be about 2 Torr to about 11 Torr, or about 8 Torr to about 10 Torr. The temperature may be at least about 550°C or at least about 600°C, or about 550°C to about 650°C.

[0070] In one example, the carbon-containing precursor is C3H6 and it is flowed at a flow rate of about 500 seem to about 2000 seem. In various embodiments, argon may be flowed concurrently at a flow rate of about 3500 seem to about 10000 seem. The electrode gap may be about 0.25 inches to about 0.4 inches. The doping gas may be flowed at a flow rate of up to about 1000 seem, or up to about 300 seem, or about 20 seem to about 550 seem, or about 30 seem to about 550 seem, or about 20 seem to about 300 seem, or less than about 150 seem. It may be preferable in some embodiments, to use a lower flow rate to maintain high density of the deposited carbon-containing material.

[0071] In some embodiments, a combination of etching from Figure 1A and co- flowing doping gas from Figure IB may be performed. Figure 1C provides an example process flow diagram depicting operations that may be performed in accordance with certain disclosed embodiments. In operation 102, a substrate is provided to a process chamber. This may be the same as operation 102 in Figure 1 A. In operation 112, the substrate is exposed to a carbon-containing precursor and a doping gas which may be a combination of operations 104 and 110 of Figure IB. In operation 106, etching is performed which may be the same as operation 106 in Figure 1A. In an operation 118, the etched carbon-containing surface is exposed to the carbon-containing precursor and doping gas again which may be the same as in operation 112. In an operation 140, operations 106 and 118 may be optionally repeated.

[0072] During operation 104, the carbon-containing precursor may be introduced in vapor or gas phase. This may be the same as operation 104 in Figure 1A.

[0073] Films deposited using certain disclosed embodiments including those described above with respect to Figures 1A, IB, and 1C may result in a roughness (AFM roughness root mean square value) of less than about 2.5 nm.

[0074] Certain disclosed embodiments are capable of depositing carbon-containing material having a high density such as at least about 2 g / cc, or at least about 2.01 g / cc, or at least about 2.02 g / cc, or at least about 2.03 g / cc, or at least about 2.04 g / cc, or at least about 2.05 g / cc, or at least about 2.06 g / cc, or at least about 2.07 g / cc, or at least about 2.08 g / cc, or at least about 2.09 g / cc, or at least about 2.1 g / cc.APPARATUS

[0075] FIG. 2 shows a schematic view of an example processing tool 200 configured for depositing an inhibitor with a low vapor pressure onto a substrate. Processing tool 200 is configured as a CVD tool. Processing tool 200 includes a processing chamber 202 and a substrate support 204 within the processing chamber. Substrate support 204 is configured to support a substrate 206 disposed within processing chamber 202. Substrate support 204 may include apedestal, a chuck, and / or any other suitable structure.

[0076] Processing chamber 202 further includes a substrate heater 208 configured to heat a substrate placed on substrate support 204. In other examples, a substrate heater may be located elsewhere within processing chamber 202, or may be omitted.

[0077] Processing tool 200 further includes a processing gas outlet 210. In some examples, processing gas outlet 210 may include a nozzle, showerhead, or other apparatus for introducing gas into processing chamber 202. Substrate support 204 can be raised and lowered to adjust the spacing between substrate 206 and processing gas outlet 210. In some examples, processing gas outlet 210 may include a heater.

[0078] Processing tool 200 further includes an optional ampoule 220 configured to hold a liquid phase processing chemical including a vapor pressure. Ampoule 220 is further configured to supply a flow of the vapor of the chemical in the ampoule by FOV. In some examples, the chemical includes an inhibitor configured to selectively deposit onto metal surfaces and inhibit oxide film growth. When ampoule 220 is holding a volume of liquid inhibitor, inhibitor in the gas phase occupies at least a portion of the ampoule. In other examples, ampoule 220 may hold a liquid phase processing chemical other than an inhibitor.

[0079] Ampoule 220 includes a FOV gas inlet 222 for flowing a carrier gas from a carrier gas source 223 into ampoule 220. Example carrier gases include N2, Ar, He, Ne, or Kr. FOV gas inlet 222 includes a mass flow controller 224 for controlling the flow of the carrier gas. In some examples, where carrier gas source 223 includes nitrogen, mass flow controller 224 is configured as a nitrogen mass flow controller. In other examples, mass flow controller 224 is configured for controlling the flow of a different carrier gas.

[0080] Ampoule 220 further includes a FOV gas outlet 226 for flowing gas out of ampoule 220. When a carrier gas is flowed through ampoule 220, the carrier gas flows over the surface of the liquid inhibitor and draws inhibitor gas through FOV gas outlet 226. Thus, the carrier gas flows with the inhibitor through FOV gas outlet 226.

[0081] Ampoule 220 further includes a bulkfill port 228 for refilling the ampoule with inhibitor from an inhibitor bulk source 230. In other examples, an ampoule may be refilled using a different method, such as by replacing a removable reservoir of inhibitor. Further, examples utilizing a liquid phase processing chemical other than an inhibitor, a bulk source of the liquid phase processing chemical other than the inhibitor may be included.

[0082] Processing tool 200 further includes an ampoule heater 234 for heating ampoule 220. Ampoule heater 234 may include any suitable configuration of one or more heating elements. In some examples, ampoule heater 234 may include a plurality of heating elements configured to apply heat to different locations on ampoule 220. As examples, ampoule heater 234 may includeone or more of a cartridge heater, a ribbon heater, a jacket heater, a molded heater, or heating coil. In some examples, ampoule heater 234 includes a heater disposed below ampoule 220 and one or more heaters disposed around the sides of ampoule 220. In other examples, ampoule heater 234 may include any other suitable configuration.

[0083] As mentioned above, an inhibitor in liquid phase may have low vapor pressure. The vapor pressure of the inhibitor may increase with temperature. As one example, an inhibitor may have a vapor pressure of < 10 torr at 60 °C, < 15 torr at 80°C, < 25 torr at 100°C, and < 50 torr at 120°C. Other liquid phase processing chemicals, including other inhibitors, may have vapor pressures outside of these ranges. By heating ampoule 220, ampoule heater 234 increases the vapor pressure of the inhibitor. This allows the processing tool 200 to deliver more inhibitor in a flow of a carrier gas.

[0084] Processing tool 200 further includes a gas box 248 including one or more gas sources. In other examples, a gas box may be separate from processing tool 200. Processing tool 200 further includes a valve 250 for controlling a flow of one or more gases from gas box 248 into processing chamber 202. Gas box 248 may includes gas sources for one or more gases. In some examples, gas box 248 includes one or more inert gases for use as a carrier gas. In various embodiments, gas box 248 is connected to showerhead 210 for delivery of vapor or gas precursors, reactants, carrier gases, and other chemistries to the processing chamber 202.

[0085] Processing tool 200 further includes a plurality of heated gas lines. More specifically, in this example, processing tool 200 includes a heated gas line 240A, a heated divert gas line 240B, and a heated maintenance vacuum line 240C. Heated gas line 240A, heated divert gas line 240B, and heated maintenance vacuum line 240C are respectively heated by gas line heaters 242A, 242B, 242C. The gas line heaters 242A, 242B, 242C are shown schematically as dashed lines. Gas line heaters 242 A, 242B, 242C each may include any suitable configuration of one or more heating elements. As examples, gas line heaters 242A, 242B, 242C each may include one or more of a jacket heater, a ribbon heater, or a molded heater. Gas line heaters 242A, 242B, 242C may be controlled to respectively heat heated gas line 240 A, heated divert gas line 240B, and heated maintenance vacuum line 240C to any suitable temperature or temperatures. The use of gas line heaters 242 A, 242B, 242C helps to prevent vapor phase inhibitor from condensing on surfaces within heated gas line 240 A, heated divert gas line 240B, and heated maintenance vacuum line 240C.

[0086] Heated gas line 240A is connected to FOV gas outlet 226. During operation, gas from FOV gas outlet 226 flows through heated gas line 240A to processing chamber 202. Gas line heater 242A is configured to heat heated gas line 240A. As mentioned above, by flowing gas through one or more heated gas lines, processing tool 200 may help avoid condensation of inhibitorwithin the heated gas lines.

[0087] Processing tool 200 further includes a divert valve system 244 disposed along heated gas line 240A. Heated divert gas line 240B is connected to divert valve system 244 and leads to an exhaust system 246. Gas line heater 242B is configured to heat heated divert gas line 240B. Exhaust system 246 is configured to receive gas outflowing from processing chamber 202 and / or one or more heated gas lines. In some examples, exhaust system 246 is configured to actively remove gas from processing chamber 202 and / or apply a partial vacuum. Exhaust system 246 may include any suitable hardware, including one or pumps.

[0088] Divert valve system 244 can be controlled to divert gas flow away from processing chamber 202 and flow gas through heated divert gas line 240B to exhaust system 246. Divert valve system 244 includes a first valve 244 A and a second valve 244B. When gas is to be diverted to exhaust system 246, divert valve system 244 can be controlled to close first valve 244A and open second valve 244B without trapping gas. As such, divert valve system 244 may help avoid condensation of the inhibitor within gas lines or valves.

[0089] Heated maintenance vacuum line 240C is configured to remove gas from ampoule 220 to exhaust system 246. Removal of carrier gas and inhibitor vapor from ampoule 220 may facilitate maintenance on ampoule 220. Gas line heater 242C is configured to heat heated maintenance vacuum line 240C. As mentioned above, exhaust system 246 may be configured to apply a partial vacuum to facilitate removal of gas from ampoule 220 and / or heated gas lines.

[0090] Processing tool 200 further includes a remote plasma system 252 configured to form a remote plasma to clean processing chamber 202. Radicals formed in the plasma may be introduced into processing chamber 202 through processing gas outlet 210. The radicals may help clean processing chamber 202 by reacting with deposited material on surfaces within processing chamber 202. Remote plasma system 252 also may be used to provide radicals for substrate processing.

[0091] Processing tool 200 further includes a main power source 254 for supplying power to components of processing tool 200, such as pumps, sensors, substrate heater 208, exhaust system 246, and valves 244A, 244B, 250. Processing tool 200 further includes an auxiliary power source 256 for supplying power to gas line heaters 242A, 242B, 242C. In some examples, gas line heaters may be powered by main power source 254 and auxiliary power source 256 may be omitted.

[0092] Processing tool 200 further includes a controller 260 for controlling operation of processing tool 200. Controller 260 is configured to control various functions of processing tool 200, such as operating substrate heater 208 to heat to a desired temperature.

[0093] Controller 260 is configured to control mass flow controller 224 to flow carrier gas into ampoule 220 at a desired flow rate. In some examples, controller 260 is configured to controlmass flow controller 224 to flow nitrogen into ampoule 220 at a flow rate within a range of 6000 to 7500 standard cubic centimeters per minute (seem). The carrier gas draws inhibitor out of ampoule 220 through FOV gas outlet 226. In some examples, the flow of nitrogen is controlled to achieve a flow of inhibitor through FOV gas outlet 226 that is within a range of 20 to 500 seem. In other examples, any other suitable flow rates may be used. Flow rates may be dependent upon inhibitor vapor pressure and / or ampoule temperature.

[0094] Controller 260 is further configured to control components of ampoule 220. In some examples, controller 260 is configured to receive a signal from ampoule 220 indicating a liquid level of inhibitor in ampoule 220. In some examples, controller 260 is configured to output liquid level information to a display (not shown in FIG. 2). In some examples, controller 260 is configured to control a bulk fill system to fill ampoule 220 with inhibitor. For example, controller 260 may control one or more pumps to pump inhibitor from inhibitor bulk source 230 into ampoule 220 through bulkfill port 228. In other examples, inhibitor may be added manually to ampoule 220. In some examples, controller 260 is configured to control ampoule 220 to fill with inhibitor based on a liquid level that is below a threshold value.

[0095] Controller 260 is further configured to control ampoule heater 234 to heat to a desired temperature. In some examples, ampoule heater may be controlled to heat an inhibitor or other liquid phase processing chemical to a temperature within a range of 20 to 130°C. In more specific examples, ampoule heater may heat to a temperature within a range of 80 to 100°C. In other examples, temperatures outside these ranges may be used. In the instance of an inhibition process, a temperature to which ampoule heater is heated depends upon a specific inhibitor contained in the ampoule and a desired vapor pressure.

[0096] Controller 260 is further configured to control gas line heaters 242 A, 242B, 242C to respectively heat heated gas line 240A, heated divert gas line 240B, heated maintenance vacuum line 240C to desired temperatures. In some examples in which the chemical in the ampoule is an inhibitor, controller 260 may control one or more gas line heaters to heat to a temperature within a range of 550 to 650 °C. Further, in some examples, gas line heaters 242A, 242B, 242C may heat the respective heated gas line 240”, heated divert gas line 240B, heated maintenance vacuum line 240C, to a temperature that is above a temperature of an ampoule heater.

[0097] Controller 260 is further configured to operate divert valve system 244 to direct inhibitor either to processing chamber 202 or to exhaust system 246. Controller 260 is further configured to operate exhaust system 246. Controller 260 is also configured to operate valve 250 and exhaust system 246 to purge processing chamber 202 by flowing an inert gas into processing chamber 202 and evacuating processing chamber 202. Controller 260 also may be configured to operate other components of processing tool 200 not shown here. Controller 260 may include any suitablecomputing system, examples of which are described below with reference to system controller 350 of Figure 3 and system controller 850 of Figure 8.

[0098] In some implementations, a controller 260 is part of a system, which may be part of the above-described examples. Such systems can include semiconductor processing equipment, including a processing tool or tools, chamber or chambers, a platform or platforms for processing, and / or specific processing components (a wafer pedestal, a gas flow system, etc.). These systems may be integrated with electronics for controlling their operation before, during, and after processing of a semiconductor wafer or substrate. The electronics may be referred to as the “controller,” which may control various components or subparts of the system or systems. The controller 260, depending on the processing requirements and / or the type of system, may be programmed to control any of the processes disclosed herein, including the delivery of processing gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings, RF matching circuit settings, frequency settings, flow rate settings, fluid delivery settings, positional and operation settings, wafer transfers into and out of a tool and other transfer tools and / or load locks connected to or interfaced with a specific system.

[0099] Broadly speaking, the controller 260 may be defined as electronics having various integrated circuits, logic, memory, and / or software that receive instructions, issue instructions, control operation, enable cleaning operations, enable endpoint measurements, and the like. The integrated circuits may include chips in the form of firmware that store program instructions, digital signal processors (DSPs), chips defined as application specific integrated circuits (ASICs), and / or one or more microprocessors, or microcontrollers that execute program instructions (e.g., software). Program instructions may be instructions communicated to the controller 260 in the form of various individual settings (or program files), defining operational parameters for carrying out a particular process on or for a semiconductor wafer or to a system. The operational parameters may, in some embodiments, be part of a recipe defined by process engineers to accomplish one or more processing steps during the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of a wafer.

[0100] The controller 260, in some implementations, may be a part of or coupled to a computer that is integrated with, coupled to the system, otherwise networked to the system, or a combination thereof. For example, the controller 260 may be in the “cloud” or all or a part of a fab host computer system, which can allow for remote access of the wafer processing. The computer may enable remote access to the system to monitor current progress of fabrication operations, examine a history of past fabrication operations, examine trends or performance metrics from a plurality of fabrication operations, to change parameters of current processing, to set processing steps to followa current processing, or to start a new process. In some examples, a remote computer (e.g. a server) can provide process recipes to a system over a network, which may include a local network or the Internet. The remote computer may include a user interface that enables entry or programming of parameters and / or settings, which are then communicated to the system from the remote computer. In some examples, the controller 260 receives instructions in the form of data, which specify parameters for each of the processing steps to be performed during one or more operations. It should be understood that the parameters may be specific to the type of process to be performed and the type of tool that the controller 260 is configured to interface with or control. Thus as described above, the controller 260 may be distributed, such as by including one or more discrete controller 260s that are networked together and working towards a common purpose, such as the processes and controls described herein. An example of a distributed controller 260 for such purposes would be one or more integrated circuits on a chamber in communication with one or more integrated circuits located remotely (such as at the platform level or as part of a remote computer) that combine to control a process on the chamber.

[0101] Without limitation, example systems may include a plasma etch chamber or module, a deposition chamber or module, a spin-rinse chamber or module, a metal plating chamber or module, a clean chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a track chamber or module, and any other semiconductor processing systems that may be associated or used in the fabrication and / or manufacturing of semiconductor wafers.

[0102] As noted above, depending on the process step or steps to be performed by the tool, the controller 260 might communicate with one or more of other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout a factory, a main computer, another controller, or tools used in material transport that bring containers of wafers to and from tool locations and / or load ports in a semiconductor manufacturing factory.

[0103] As described above, one or more process stations may be included in a multi-station processing tool. Figure 3 depicts an example processing apparatus according to disclosed embodiments. Tool 300 includes a first processing chamber 302 and a second processing chamber 304. The first processing chamber 302 includes a plurality of processing stations, four stations 380A-D, that each may process a wafer. The first processing chamber 302 is configured to perform plasma treatment operations on the wafers. The second processing chamber 304 is configured to perform deposition on the wafer and may be considered a deposition chamber. Thesecond processing chamber 304 also includes a plurality of processing stations, four stations 382A-D, that each may process a wafer. The first and second processing chambers 302 and 304 may be considered multi-station processing chambers.

[0104] Tool 300 also includes a wafer transfer unit configured to transport one or more wafers within the tool 300. Additional features of tool 300 will be discussed in greater detail below, and various features are discussed here with respect to some of the described techniques. In the depicted illustration, the wafer transfer unit includes a first robotic arm unit 308 in a first wafer transfer module 310 and a second robotic arm unit 312 in a second wafer transfer module 314 that may be considered an equipment front end module (EFEM) configured to received containers for wafers, such as a front opening unified module (FOUP) 316. The first robotic arm unit 308 is configured to transport a wafer between the first processing chamber 302 and the second processing chamber 304, and between the second the second robotic arm unit 312. The second robotic arm unit 312 is configured to transport the wafer between a FOUP and the first robotic arm unit 308. After a wafer has been treated in the first processing chamber 302, the wafer transfer unit is able to transfer the wafer from the first processing chamber 302, to the second processing chamber 304 where one or more layers of encapsulation material may be deposited on one or more wafers.

[0105] Similar to above, the first wafer transfer module 310 may a vacuum transfer module (VTM). Airlock 320, also known as a loadlock or transfer module, is shown and may be individually optimized to perform various fabrication processes. The tool 300 also includes a FOUP 316 that is configured to lower the pressure of the tool 300 to a vacuum or low pressure, e.g., between about 1 mTorr and about 10 Torr, and maintain the tool 300 at this pressure. This includes maintaining the first and second processing chambers 302 and 304, and the first wafer transfer module 310 at the vacuum or low pressure. The second wafer transfer module 314 may be at a different pressure, such as atmospheric. As the wafer is transferred throughout the tool 300, it is therefore maintained at the vacuum or low pressure. For example, as the wafer is transferred from the first processing chamber 302, into the first wafer transfer module 310, and to the second processing chamber 304, the wafer is maintained at the vacuum or low pressure and not exposed to atmospheric pressure.

[0106] In a further example, a substrate is placed in one of the FOUPs 318 and the second robot arm unit 312, or front-end robot, transfers the substrate from the FOUP 318 to an aligner, which allows the substrate to be properly centered before it is etched, or deposited upon, or otherwise processed. After being aligned, the substrate is moved by the second robot arm unit 312 into the airlock 320. Because airlock modules have the ability to match the environment between an ATM and a VTM, the substrate is able to move between the two pressure environments without beingdamaged. From the airlock 320, the substrate is moved by the first robot arm unit 308 through the first wafer transfer module 310, or VTM 310, and into the first processing chamber 302. In order to achieve this substrate movement, the first robot arm unit 308 uses end effectors on each of its arms.

[0107] Figure 3 also depicts an embodiment of a system controller 329 employed to control process conditions and hardware states of tool 300. System controller 329 may include one or more memory devices (not shown), one or more mass storage devices (not shown), and one or more processors (not shown). Processors may include a CPU or computer, analog, and / or digital input / output connections, stepper motor controller boards, etc.

[0108] As described above, one or more process stations may be included in a multi-station processing tool. Figure 4 shows a schematic view of an embodiment of a multi-station processing tool 400 with an inbound load lock 402 and an outbound load lock 404, either or both of which may include a remote plasma source. A robot 406, at atmospheric pressure, is configured to move substrates or wafers from a cassette loaded through a pod 408 into inbound load lock 402 via an atmospheric port 410. A substrate is placed by the robot 406 on a pedestal 412 in the inbound load lock 402, the atmospheric port 410 is closed, and the load lock is pumped down. Where the inbound load lock 402 includes a remote plasma source, the substrate may be exposed to a remote plasma treatment in the load lock prior to being introduced into a processing chamber 414. Further, the substrate also may be heated in the inbound load lock 402 as well, for example, to remove moisture and adsorbed gases. Next, a chamber transport port 416 to processing chamber 414 is opened, and another robot (not shown) places the substrate into the reactor on a pedestal of a first station shown in the reactor for processing. While the embodiment depicted in Figure 4 includes load locks, it will be appreciated that, in some embodiments, direct entry of a substrate into a process station may be provided. In various embodiments, the soak gas is introduced to the station when the substrate is placed by the robot 406 on the pedestal 412.

[0109] The depicted processing chamber 414 includes four process stations, numbered from 1 to 4 in the embodiment shown in Figure 4. Each station has a heated pedestal (shown at 418 for station 1), and gas line inlets. It will be appreciated that in some embodiments, each process station may have different or multiple purposes. For example, in some embodiments, a process station may be switchable between an ALD and PEALD process mode. Additionally or alternatively, in some embodiments, processing chamber 414 may include one or more matched pairs of ALD and plasma-enhanced ALD process stations. While the depicted processing chamber 414 includes four stations, it will be understood that a processing chamber according to the present disclosure may have any suitable number of stations. For example, in some embodiments, a processing chamber may have five or more stations, while in other embodiments a processing chamber may have threeor fewer stations.

[0110] Figure 4 depicts an embodiment of a wafer handling system 490 for transferring substrates within processing chamber 414. In some embodiments, wafer handling system 490 may transfer substrates between various process stations and / or between a process station and a load lock. It will be appreciated that any suitable wafer handling system may be employed. Nonlimiting examples include wafer carousels and wafer handling robots. Figure 4 also depicts an embodiment of a system controller 450 employed to control process conditions and hardware states of process tool 400. System controller 450 may include one or more memory devices 456, one or more mass storage devices 454, and one or more processors 452. Processor 452 may include a CPU or computer, analog and / or digital input / output connections, stepper motor controller boards, etc. In some embodiments, system controller 450 includes machine-readable instructions for performing operations such as those described above with respect to Figures 2, 3, and 4.

[0111] In some embodiments, system controller 450 controls the activities of process tool 400. System controller 450 executes system control software 458 stored in mass storage device 454, loaded into memory device 456, and executed on processor 452. Alternatively, the control logic may be hard coded in the controller 450. Applications Specific Integrated Circuits, Programmable Logic Devices (e.g., field-programmable gate arrays, or FPGAs) and the like may be used for these purposes. In the following discussion, wherever “software” or “code” is used, functionally comparable hard coded logic may be used in its place. System control software 458 may include instructions for controlling the timing, mixture of gases, amount of gas flow, chamber and / or station pressure, chamber and / or station temperature, substrate temperature, target power levels, RF power levels, substrate pedestal, chuck and / or susceptor position, and other parameters of a particular process performed by process tool 400. System control software 458 may be configured in any suitable way. For example, various process tool component subroutines or control objects may be written to control operation of the process tool components used to carry out various process tool processes. System control software 458 may be coded in any suitable computer readable programming language.EXPERIMENTALEXPERIMENT 1

[0112] An experiment was conducted on a first substrate by depositing carbon-containing on a substrate surface without doping and without etching, and on a second substrate by depositing a carbon-containing material on a substrate surface without doping and with etching (e.g., in accordance with certain disclosed embodiments). The stress and density was evaluated and images of the deposited materials were observed.

[0113] The stress and density are summarized in Table 1. As shown, the high density was maintained and stress was similar. The observations of the deposited materials showed that the substrate surface was rough with many bumps and columnar growth or pileus structure formations for the first substrate, but the second substrate showed no surface roughness and no columnar growth was observed.Table 1. Stress and DensityCONCLUSION

[0114] Although the foregoing embodiments have been described in some detail for purposes of clarity of understanding, it will be apparent that certain changes and modifications may be practiced within the scope of the appended claims. It should be noted that there are many alternative ways of implementing the processes, systems, and apparatus of the present embodiments. Accordingly, the present embodiments are to be considered as illustrative and not restrictive, and the embodiments are not to be limited to the details given herein.

Claims

CLAIMSWhat is claimed is:

1. A method for processing substrates, the method comprising: providing a substrate to a process chamber; exposing the substrate to a carbon-containing precursor to deposit a partial layer of a carbon-containing material onto a substrate surface to a thickness sufficient to achieve growth of the carbon-containing material without forming columnar growth of the carbon-containing material on the substrate surface; exposing the partial layer of the carbon-containing material to a sputtering gas in a plasma environment; and repeating exposing the substrate to the carbon-containing precursor and exposing partially deposited carbon-containing material to the sputtering gas in the plasma environment in cycles.

2. The method of claim 1 , further comprising co-flowing a doping gas with the carbon- containing precursor to the process chamber when depositing the partial layer of the carbon-containing material.

3. A method for processing substrates, the method comprising: providing a substrate to a process chamber; introducing a carbon-containing precursor to the process chamber to deposit a partial layer of a carbon-containing material onto a substrate surface; and co-flowing a doping gas with the carbon-containing precursor to the process chamber when depositing the partial layer of the carbon-containing material.

4. The method of claim 3, further comprising stopping flow of the carbon-containing precursor and the doping gas after the partial layer of the carbon-containing material is deposited to a thickness sufficient to achieve growth of the carbon-containing material without forming columnar growth of the carbon-containing material on the substrate surface and introducing a sputtering gas in a plasma environment to partially etch the partial layer of the carbon-containing material.

5. The method of claim 4, further comprising alternating between the depositing and the introducing of the sputtering gas.

6. The method of any of claims 1, 2, 4, or 5, wherein the sputtering gas is selected from the group consisting of argon, krypton, xenon, radon, and combinations thereof.

7. The method of any of claims 1 , 2, 4, or 5, further comprising flowing a carrier gas with the sputtering gas.

8. The method of claim 7, wherein the carrier gas is selected from the group consisting of nitrogen gas, helium, and combinations thereof.

9. The method of any of claims 1 , 2, 4, or 5, wherein the plasma environment is generated using a dual frequency plasma.

10. The method of any of claims 1-5, wherein the substrate is heated to a temperature of about 550°C to about 650°C.

11. The method of any of claims 2-5, wherein the doping gas is a hydrogen-containing gas.

12. The method of any of claims 2-5, wherein the doping gas is a fluorine-containing gas.

13. The method of any of claims 2-5, wherein the doping gas is selected from the group consisting of silane (Si U), diborane (ETHe), boron trifluoride (BF3), sulfur hexafluoride (SFe), tungsten pentafluoride (WF5), tungsten hexafluoride (WFe), and combinations thereof.

14. The method of any of claims 2-5, wherein the doping gas is delivered in a plasma environment.

15. The method of claim 14, wherein the plasma environment is generated using a dual frequency plasma.

16. The method of any of claims 1-2, wherein a second plasma is ignited when exposing the substrate to the carbon-containing precursor to deposit the carbon-containing material by plasma enhanced chemical vapor deposition.

17. The method of any of claims 3-5, wherein a second plasma is ignited when introducing the carbon-containing precursor to the process chamber to deposit the partial layer of the carbon-containing material onto the substrate surface.

18. The method of any of claims 1-3 and 5, wherein the sputtering gas causes generation of ions.

19. The method of any of claims 1-5, wherein the carbon-containing material is not amorphous carbon.

20. The method of any of claims 1-5, wherein the carbon-containing material ha s a density of greater than 2.0 g / cc.

21. An apparatus for processing substrates, the apparatus comprising: one or more process chambers, each process chamber comprising a chuck; one or more gas inlets into the process chambers and associated flow-control hardware; a plasma generator; and a controller having at least one processor and a memory, wherein the at least one processor and the memory are communicatively connected with one another, the at least one processor is at least operatively connected with the flow-control hardware, and the memory stores computer-executable instructions for controlling the at least one processor to at least control the flow-control hardware to: cause introduction of a carbon-containing precursor to the one or more process chamber for a duration sufficient to deposit a partial layer of a carbon-containing material onto a substrate surface to a thickness sufficient to achieve growth of the carbon- containing material without forming columnar growth of the carbon-containing material on the substrate surface; cause stopping of the introduction of the carbon-containing precursor prior to introduction of a sputtering gas and generation of a plasma; and cause repeating of the introduction of the carbon-containing precursor and the introduction of the sputtering gas and generation of the plasma in cycles.

22. The apparatus of claim 21, wherein the controller further comprises instructions to cause co-flowing of a doping gas with the carbon-containing precursor to the process chamber.

23. An apparatus for processing substrates, the apparatus comprising: one or more process chambers, each process chamber comprising a chuck; one or more gas inlets into the process chambers and associated flow-control hardware; a plasma generator; and a controller having at least one processor and a memory, wherein the at least one processor and the memory are communicatively connected with one another, the at least one processor is at least operatively connected with the flow-control hardware, andthe memory stores computer-executable instructions for controlling the at least one processor to at least control the flow-control hardware to: cause introduction of a carbon-containing precursor to the process chamber to deposit a partial layer of a carbon-containing material onto a substrate surface; and cause co-flowing of a doping gas with the carbon-containing precursor to the process chamber when depositing the partial layer of the carbon-containing material.

24. The apparatus of claim 23, wherein the controller further comprises instructions to cause stopping of the flow of the carbon-containing precursor and the doping gas after the partial layer of the carbon-containing layer is deposited to a thickness sufficient to deposit a partial layer of a carbon-containing material onto a substrate surface to a thickness sufficient to achieve growth of the carbon-containing material without forming columnar growth of the carbon-containing material on the substrate surface and cause introduction of a sputtering gas and generation of a plasma.

25. The apparatus of claim 24, wherein the controller further comprises instructions for causing alternating between the depositing and the introducing of the sputtering gas.

26. The apparatus of any of claims 21 or 23, wherein electrodes for generating a plasma are set apart in gap having a gap distance of about 0.25 inches to about 0.4 inches.

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