Dual nitrogen flow capability for low fluorine tungsten deposition

Abstract

A gas delivery system for a process chamber includes a first flow path coupled to a reducing gas source and configured to supply reducing gas from the reducing gas source to the process chamber; a second flow path coupled to the precursor gas source and configured to supply the precursor gas to the processing chamber from the precursor gas source; a third flow path coupled to the first nitrogen gas source and configured to co-flow the first nitrogen gas from the first nitrogen gas source into the processing chamber while supplying the reducing gas to the processing chamber; and a fourth flow path coupled to the second nitrogen gas source and configured to co-flow the second nitrogen gas from the second nitrogen gas source into the processing chamber while supplying the precursor gas to the processing chamber.

Description

Cross - Reference to Related Applications

[0001] This application claims the benefit of U.S. Provisional Application No. 63 / 421,751, filed on November 2, 2022. The entire disclosure of the above application is incorporated herein by reference. Technical Field

[0002] This disclosure relates to substrate processing systems, and more particularly to substrate processing systems configured to use low - fluorine tungsten for deposition. Background Art

[0003] The background description provided here is for the purpose of generally presenting the background of the disclosure. The work of the currently named inventors (to the extent described in this background section) and aspects of the specification that may not qualify as prior art at the time of filing are not expressly or implicitly admitted as prior art against the disclosure.

[0004] Substrate processing systems are used to perform processes such as film deposition and etching on substrates such as semiconductor wafers. For example, chemical vapor deposition (CVD), atomic layer deposition (ALD), and / or other deposition processes can be used for deposition to deposit conductive films, dielectric films, or other types of films. During deposition, the substrate is disposed on a substrate support, and one or more precursor gases can be supplied to the processing chamber during one or more process steps. Plasma can be used to initiate chemical reactions. After deposition is performed, the process gas is evacuated and the substrate is removed from the processing chamber.

[0005] In some examples, the process gas for deposition contains tungsten. Tungsten - containing materials can be used for depositing semiconductor structures, such as horizontal interconnects, vias between adjacent metal layers, contacts between metal layers, etc. Tungsten - containing materials can be used for some structures with complex patterning, such as 3D NAND structures with high aspect ratio features. Summary of the Invention

[0006] A gas delivery system for a processing chamber in a substrate processing system includes: a first flow path coupled to a reducing gas source and configured to supply a reducing gas from the reducing gas source to the processing chamber; a second flow path coupled to a precursor gas source and configured to supply a precursor gas from the precursor gas source to the processing chamber; a third flow path coupled to a first nitrogen gas source and configured to co - flow a first nitrogen gas from the first nitrogen gas source into the processing chamber while supplying the reducing gas to the processing chamber; and a fourth flow path coupled to a second nitrogen gas source and configured to co - flow a second nitrogen gas from the second nitrogen gas source into the processing chamber while supplying the precursor gas to the processing chamber.

[0007] In other features, the precursor gas is a tungsten - containing precursor gas. The precursor gas contains WF 6。The reducing gas contains molecular hydrogen. The first nitrogen gas and the second nitrogen gas each contain molecular nitrogen. The first flow path, the second flow path, the third flow path, and the fourth flow path each contain at least one valve and a mass flow controller.

[0008] Among other features, the first flow path includes a first valve coupled to a reducing gas source, a first mass flow controller coupled to the first valve, and a first manifold coupled between the first mass flow controller and the processing chamber; the second flow path includes a second valve coupled to a precursor gas source, a second mass flow controller coupled to the second valve, and a second manifold coupled between the second mass flow controller and the processing chamber; the third flow path includes a third valve coupled to a first nitrogen gas source, a third mass flow controller coupled to the third valve, and a third manifold coupled between the third mass flow controller and the processing chamber; and the fourth flow path includes a fourth valve coupled to a second nitrogen gas source, a fourth mass flow controller coupled to the fourth valve, and a fourth manifold coupled between the fourth mass flow controller and the processing chamber.

[0009] Among other features, the third flow path is coupled to the first flow path between the first manifold and the processing chamber, and the fourth flow path is coupled to the second flow path between the second manifold and the processing chamber. The claimed gas delivery system further includes a controller configured to control the first, second, third, and fourth valves and the first, second, third, and fourth mass flow controllers such that the first nitrogen gas coflows with the reducing gas into the processing chamber and the second nitrogen gas coflows with the precursor gas into the processing chamber. The precursor gas is a tungsten-containing precursor gas, the reducing gas contains molecular hydrogen, and the first nitrogen gas and the second nitrogen gas each contain molecular nitrogen. The processing chamber is configured to perform a low-fluorine tungsten deposition process. The tungsten-containing precursor gas contains WF 6 。The controller is configured to control the gas delivery system such that the flow rate of the first nitrogen gas coflowing with the reducing gas is greater than the flow rate of the second nitrogen gas coflowing with the precursor gas.

[0010] A substrate processing system configured to perform a low-fluorine tungsten deposition process on a substrate disposed in a processing chamber includes a gas delivery system configured to supply a tungsten-containing precursor gas, a reducing gas, a first nitrogen gas, and a second nitrogen gas to the processing chamber, respectively. The controller is configured to control the gas delivery system to perform a plurality of deposition cycles by controlling the gas delivery system to cause the first nitrogen gas to coflow with the reducing gas in a first dosing stage and the second nitrogen gas to coflow with the precursor gas in a second dosing stage in each deposition cycle.

[0011] Among other features, the controller is configured to control a gas delivery system such that a first nitrogen gas coflows with a reducing gas at a first flow rate and such that a second nitrogen gas coflows with a precursor gas at a second flow rate, and the first flow rate is greater than the second flow rate. The controller is configured to control the gas delivery system to coflow a first nitrogen gas from a first nitrogen gas source and to coflow a second nitrogen gas from a second nitrogen gas source separate from the first nitrogen gas source. The controller is configured to control the gas delivery system to selectively purge a processing chamber between a first feed stage and a second feed stage. The controller is configured to control the gas delivery system to coflow the first nitrogen gas and the second nitrogen gas during deposition of a nucleation layer of tungsten-containing material and during bulk fill deposition. The precursor gas is WF 6 , the reducing gas is molecular hydrogen, and the first nitrogen gas and the second nitrogen gas are each molecular nitrogen.

[0012] A method for performing a low-fluorine tungsten deposition process to deposit a tungsten-containing material on a substrate includes supplying a reducing gas to a processing chamber containing the substrate during a first feed stage of a deposition cycle, and coflowing a first nitrogen gas with the reducing gas while supplying the reducing gas to the processing chamber during the first feed stage. Coflowing the first nitrogen gas includes supplying the first nitrogen gas from a first nitrogen gas source. The method further includes supplying a tungsten-containing precursor gas to the processing chamber during a second feed stage of the deposition cycle after the first feed stage, and coflowing a second nitrogen gas with the tungsten-containing precursor gas while supplying the tungsten-containing precursor gas to the processing chamber during the second feed stage. Coflowing the second nitrogen gas includes supplying the second nitrogen gas from a second nitrogen gas source separate from the first nitrogen gas source. The flow rate of the first nitrogen gas during the first feed stage is greater than the flow rate of the second nitrogen gas during the second feed stage.

[0013] From the detailed description, the claims, and the drawings, further applicable fields of the present disclosure will become apparent. The detailed description and specific examples are for illustrative purposes only and are not intended to limit the scope of the present disclosure. Description of the Drawings

[0014] The present disclosure can be more fully understood from the following detailed description and the accompanying drawings, in which:

[0015] Figure 1 is a functional block diagram of an example of a substrate processing system according to the present disclosure;

[0016] Figure 2 is a functional block diagram of an exemplary gas delivery system according to the present disclosure;

[0017] Figure 3 shows an exemplary deposition cycle of a low-fluorine tungsten deposition process according to the present disclosure; and

[0018] Figure 4 shows the steps of an exemplary method for performing low-fluorine tungsten deposition according to the present disclosure.

[0019] In the accompanying drawings, reference numerals may be reused to identify similar and / or identical elements. Detailed Description

[0020] A substrate processing system and a processing chamber may be configured to deposit tungsten (W) on a semiconductor substrate to form features such as vias, electrical contacts, metal layers, etc. For example, a tungsten nucleation layer is first deposited into the vias or contact regions. The tungsten nucleation layer may be deposited to conformally coat the sidewalls and bottoms of the features. Conformality with the sidewalls and bottoms may be critical to support high-quality deposition. In some examples, the nucleation layer is deposited using atomic layer deposition (ALD) or pulsed nucleation layer (PNL) processes.

[0021] In ALD and PNL processes, reactant pulses are sequentially injected into the processing chamber and purged from the processing chamber (e.g., using alternating pulses of reactants and purge gases). A first reactant may adsorb onto the substrate, and a second reactant reacts with the first reactant. The process is repeated in a cyclic manner until the desired deposition thickness is obtained.

[0022] After depositing the tungsten nucleation layer, bulk tungsten may be deposited (e.g., using a chemical vapor deposition (CVD) process) by reducing tungsten hexafluoride (WF 2 ) with a reducing agent (e.g., molecular hydrogen (H 6 ). The bulk tungsten used herein refers to tungsten that is used to fill most or all of the features (e.g., at least about 50% of the features). The nucleation layer is a thin conformal film configured to facilitate the subsequent formation of the bulk material, while the bulk tungsten is configured to conduct current. Generally, the bulk tungsten has a larger grain size and a lower resistivity relative to the nucleation layer or film. In some examples, the bulk tungsten is tungsten having a deposition thickness of at least .

[0023] As semiconductor devices scale to smaller technology nodes and more complex patterning structures, achieving uniform conformal deposition can become difficult. The distribution of material within a feature or structure can be characterized by the step coverage of the material. "Step coverage" is defined as the ratio of two thicknesses. For example, step coverage can refer to the thickness of the material inside a feature divided by the thickness of the material near the opening of the feature. "Inside the feature" can refer to the middle portion of the feature located at approximately the midpoint along the depth of the feature. In some examples, the middle portion corresponds to the region between about 25% and 75% of the distance along the depth of the feature measured from the feature opening, or in certain embodiments, between about 40% and 60% of that distance. In other examples, "inside the feature" corresponds to the end portion of the feature located between about 75% and 95% of the distance along the depth of the feature measured from the opening. The "opening" of the feature corresponds to the top of the feature within 25% or more specifically within 10% of the opening edge. For example, step coverage greater than 100% can be obtained by filling a feature that is wider near the middle or bottom of the feature than at the feature opening.

[0024] In addition, reducing the fluorine concentration or content in the deposited tungsten film improves device performance. As feature sizes decrease, the amount of fluorine in the tungsten film has an increasingly greater impact on device performance. For example, as feature sizes decrease, the thickness of the deposited tungsten film also decreases. As a result, fluorine is more likely to diffuse through the thinner deposited tungsten film, which can lead to device failure.

[0025] For certain structures (e.g., 3D NAND structures), it is also desirable to reduce the sidewall surface roughness of the features. Various techniques can be used to deposit tungsten with reduced roughness. For example, some substrate processing systems are configured to implement a low-fluorine tungsten (LFW) deposition process to obtain smooth tungsten growth and improve step coverage.

[0026] In some examples, tungsten is deposited by flowing a carrier gas and alternately flowing a tungsten-containing precursor gas (e.g., WF 6 ) and a reducing gas (e.g., molecular hydrogen or H 2 ) while flowing the carrier gas. A purge gas (e.g., an inert gas) can be supplied between pulses of the tungsten-containing precursor gas and the reducing gas. In some examples, nitrogen (e.g., molecular nitrogen or N 2 ) co-flows with the tungsten-containing precursor gas or the reducing gas to reduce the sidewall surface roughness. Nitrogen is beneficial for occupying surface binding sites to increase surface mobility. Exemplary LFW deposition techniques involving co-flowing nitrogen are described in more detail in U.S. Patent Publication No. 2021 / 0335617, the entire contents of which are incorporated herein by reference.

[0027] The LFW deposition system and method according to the present disclosure are configured to selectively co - flow nitrogen with either a tungsten - containing precursor gas, a reducing gas, or both. For example, different nitrogen gas sources are respectively connected to their respective tungsten - containing precursor gas and reducing gas flow paths and independently controlled. For instance, different nitrogen gas sources are controlled separately in the nucleation and bulk deposition steps. In other words, the respective flow rates of nitrogen co - flowing with the tungsten - containing precursor gas and the reducing gas can be varied. In this way, sidewall surface roughness and filling performance are improved.

[0028] Now referring Figure 1 , an example of a substrate processing system 100 according to the present disclosure including a substrate support 104 (e.g., a pedestal configured for CVD and / or ALD deposition) is shown. The substrate support 104 is disposed within a processing chamber 108. During processing, a substrate 112 is disposed on the substrate support 104. For example, deposition is performed on the substrate 112. The substrate 112 is removed and one or more additional substrates are processed.

[0029] The gas delivery system 120 includes gas sources 122 - 1, 122 - 2, …… and 122 - N (collectively referred to as gas sources 122), which are connected to valves 124 - 1, 124 - 2, …… and 124 - N (collectively referred to as valves 124) and mass flow controllers 126 - 1, 126 - 2, …… and 126 - N (collectively referred to as MFC 126). The MFC 126 controls the gas flow from the gas sources 122 to a manifold 128, where the gases are mixed. One or more pressure sensors 130 may be disposed in the manifold 128 to measure pressure. The output of the manifold 128 is supplied to a gas distribution device, such as a multi - injector showerhead 140. Although a manifold 128 is shown, multiple (e.g., two or more) manifolds may be used, as described in more detail below.

[0030] In some examples, a resistive heater 144 may be used to control the temperature of the substrate support 104. The substrate support 104 may include coolant channels 148. A coolant fluid is supplied from a fluid reservoir 150 to the coolant channels 148 using a pump 152. Valves 154 and a pump 156 may be used to evacuate reactants from the processing chamber 108 and / or control the pressure within the processing chamber 108.

[0031] The controller 160 includes a feed controller 164, which controls the feed provided by the multi - injector showerhead 140. The controller 160 also controls the gas delivery from the gas delivery system 120. The controller 160 uses the valves 154 and the pump 156 to control the pressure within the processing chamber and / or the evacuation of reactants. The controller 160 controls the temperature of the substrate support 104 and the substrate 112 based on temperature feedback (e.g., from sensors (not shown) in the substrate support and / or sensors (not shown) measuring the coolant temperature).

[0032] In some examples, the substrate processing system 100 may be further configured to etch the substrate 112 within the same processing chamber 108. Accordingly, the substrate processing system 100 may include components such as an RF generation system configured to generate and supply RF power to the upper and / or lower electrodes, a matching and distribution network configured to generate a plasma within the processing chamber 108 to etch the substrate 112, and the like.

[0033] The substrate processing system 100 according to the present disclosure is configured to implement LFW deposition, as described in more detail below. The gas delivery system 120 is configured to co-flow nitrogen independently with a tungsten-containing precursor gas, a reducing gas, or any one of the two (e.g., in response to the controller 160). For example, the gas source 122 includes two different nitrogen gas sources, which are respectively connected to the corresponding tungsten-containing precursor gas and reducing gas flow paths of the gas delivery system 120, as described in more detail below.

[0034] Figure 2 An exemplary gas delivery system 200 and a controller 204 according to the present disclosure are shown. The gas delivery system 200 includes a gas source, including but not limited to a precursor gas (e.g., a tungsten-containing precursor gas such as WF 6 ) source 208-1, a reducing gas (e.g., H 2 ) source 208-2, a first nitrogen gas source 208-3, a second nitrogen gas source 208-4, and other gas sources (e.g., a carrier gas source, a purge gas source, etc.) 208-5 (collectively referred to as the gas source 208). Although described herein with respect to WF 6 , the principles of the present disclosure may also be implemented in LFW deposition processes using other tungsten-containing gases. In some examples, other reducing gases (e.g., borane, silane, or germane gases) may be used. The gas source 208 is coupled to corresponding valves 212-1, 212-2, 212-3, 212-4, and 212-5 (collectively referred to as the valves 212) and mass flow controllers (MFCs) 216-1, 216-2, 216-3, 216-4, and 216-5 (collectively referred to as the MFCs 216).

[0035] The MFC 216 controls the gas flow from the gas source 208 to the manifold 220, where the gases are mixed. The mixed gas is supplied from the manifold 220 to the processing chamber 224 (e.g., via a gas distribution device such as the above-mentioned Figure 1(the showerhead described in). As shown, the corresponding manifolds 228-1, 228-2, 228-3, 228-4, and 228-5 (collectively referred to as manifold 228) can be arranged between the gas source 208 and the manifold 220 in each flow path. For simplicity, other components (e.g., additional valves in each flow path, such as the corresponding valves between manifold 228 and manifold 220) are omitted.

[0036] The gas delivery system 200 and the controller 204 are configured to independently co-flow nitrogen gas from the first nitrogen gas source 208-3 and the second nitrogen gas source 208-4 with the precursor gas from the precursor gas source 208-1, the reducing gas from the reducing gas source 208-2, or one of the two. For example, the controller 204 is configured to control the valves 212, MFC 216, and other components to supply the carrier gas, precursor gas, and reducing gas to the processing chamber 224 for tungsten nucleation and bulk deposition, and further selectively co-flow nitrogen gas with the precursor gas and the reducing gas.

[0037] For example, as shown, the first nitrogen gas source 208-3 is coupled to the flow path of the reducing gas (e.g., supply line 232). The second nitrogen gas source 208-4 is coupled to the flow path of the precursor gas (e.g., supply line 236). The controller 204 independently controls the nitrogen gas flow rates from the first nitrogen gas source 208-3 and the second nitrogen gas source 208-4 via the corresponding valves 212 and MFC 216. As shown, the flow path of the first nitrogen gas source 208-3 is configured for selective fluid communication with the supply line 232 via the supply line 240. The flow path of the second nitrogen gas source 208-4 is configured for selective fluid communication with the supply line 236 via the supply line 244. By way of example only, the controller 160 includes a feed controller (e.g., Figure 1 the feed controller 164), which is configured to independently control the feeding of the precursor gas, reducing gas, and nitrogen gas from each nitrogen gas source 208-3 and 208-4. In this way, the co-flow of nitrogen gas with the precursor gas and the reducing gas can be independently controlled throughout the deposition process.

[0038] Now referring to Figure 3 and continuing to refer to Figure 2 , an exemplary deposition cycle of the LFW deposition process according to the present disclosure is described. Figure 3 The deposition cycle described in can correspond to the nucleation or bulk filling deposition of tungsten-containing materials.

[0039] As shown, each deposition cycle consists of a pair of alternating reducing gases (e.g., H 2 ; as shown in 300) and tungsten-containing precursor gases (e.g., WF 6; composed of pulses as shown at 304). In other words, a deposition cycle can include a reducing gas pulse and a precursor gas pulse. As shown at 308, a purge gas pulse can be supplied during a purge phase between the reducing gas and precursor gas pulses and / or between deposition cycles. Although Figure 3 not shown in, a carrier gas can be supplied continuously or periodically during each deposition cycle.

[0040] As described above, the gas delivery system 200 is configured to co - flow nitrogen with both the reducing gas and the precursor gas. For example, in a first stage (e.g., a first feeding stage), the reducing gas and nitrogen from the first nitrogen gas source 208 - 3 (i.e., the first nitrogen, as shown at 312) are each pulsed (i.e., opened), while the precursor gas and nitrogen from the second nitrogen gas source 208 - 4 are closed. In a second stage (e.g., a first purge stage), the reducing gas, the nitrogen from the first nitrogen gas source 208 - 3, the precursor gas, and the nitrogen from the second nitrogen gas source 208 - 4 are each closed, and the purge gas is opened.

[0041] In a third stage (e.g., a second feeding stage), the precursor gas and nitrogen from the second nitrogen gas source 208 - 4 (i.e., the second nitrogen, as shown at 316) are each pulsed (i.e., opened), while the reducing gas and the nitrogen from the first nitrogen gas source 208 - 3 are each closed. In a fourth stage (e.g., a second purge stage), the reducing gas, the nitrogen from the first nitrogen gas source 208 - 3, the precursor gas, and the nitrogen from the second nitrogen gas source 208 - 4 are each closed, and the purge gas is opened. The first stage, second stage, third stage, and fourth stage are repeated in subsequent deposition cycles.

[0042] As Figure 3 shown, in each deposition cycle, nitrogen co - flows from the respective nitrogen gas source with each reducing gas pulse and each precursor gas pulse. Further, nitrogen co - flows throughout each reducing gas pulse and each precursor gas pulse. In other words, the duty cycles of the reducing gas and the first nitrogen are approximately the same, and the duty cycles of the precursor gas and the second nitrogen are approximately the same. However, the respective duty cycles (i.e., on and off times) of the reducing gas, the precursor gas, the first nitrogen, and the second nitrogen can be different, can vary in each deposition cycle, and so on.

[0043] In one example, the first nitrogen gas co - flows with the reducing gas in each deposition cycle, while the second nitrogen gas co - flows with the precursor gas only in every other deposition cycle. In another example, the first nitrogen gas co - flows with the reducing gas in every other deposition cycle, while the second nitrogen gas co - flows with the precursor gas in each deposition cycle. In other examples, the first nitrogen gas and / or the second nitrogen gas co - flow only during selected deposition cycles (e.g., during the first part of the deposition process, during the ending part of the deposition process, etc.).

[0044] In other examples, the duration and / or amplitude of each pulse of the first nitrogen gas and the second nitrogen gas can vary. For example, the first nitrogen gas and the second nitrogen gas can be pulsed only during selected portions of each pulse of the reducing gas and the precursor gas, respectively. In another example, the first nitrogen gas and the second nitrogen gas are pulsed throughout each pulse of the reducing gas and the precursor gas, respectively, but at different flow rates. In still other examples, the flow rates of the first nitrogen gas and the second nitrogen gas can vary between cycles.

[0045] In this way, the co - flow time and rate of the first nitrogen gas and the second nitrogen gas can be varied to minimize the side - wall surface roughness of the deposited tungsten - containing film. In one example, the co - flow rate of the first nitrogen gas with the reducing gas is greater than the co - flow rate of the second nitrogen gas with the precursor gas. For example, the co - flow rate of the first nitrogen gas is greater than 500 sccm. In one example, the co - flow rate of the first nitrogen gas is greater than the flow rate of the reducing gas (e.g., greater than 3000 sccm). Co - flowing the first nitrogen gas at a flow rate greater than both the flow rate of the reducing gas and the flow rate of the second nitrogen gas can reduce the side - wall roughness by 40% or more.

[0046] Figure 4 Steps of an exemplary method 400 for low - fluorine tungsten deposition according to the present disclosure are shown. The described method 400 can be applied to both the nucleation layer deposition and the bulk fill deposition processes. In some examples (e.g., for nucleation layer deposition), the tungsten - containing precursor gas can be supplied first in each deposition cycle, and then the reducing gas or reducing agent is supplied after the tungsten - containing precursor. In other examples (e.g., for bulk tungsten deposition), the reducing gas is supplied first in each deposition cycle, and then the precursor gas is supplied after the reducing gas. As described below, each step of method 400 can be performed using Figure 2 the gas delivery system 200 and the controller 204 described in.

[0047] In Figure 4 the example shown, a reducing gas is supplied to the processing chamber at 404 to expose the substrate to the reducing gas. At 408, the first nitrogen gas is supplied to the processing chamber from a first nitrogen gas source. The first nitrogen gas supplied at 408 can occur simultaneously with the supply of the reducing gas at 404, as referenced above Figure 3As described. In one example, the first nitrogen gas co - flows at a flow rate greater than the flow rate of the reducing gas. Optionally, the processing chamber is purged at 412.

[0048] At 416, a tungsten - containing precursor gas is supplied to the processing chamber to expose the substrate to the precursor gas. At 420, a second nitrogen gas is supplied to the processing chamber from a second nitrogen gas source. The supply of the second nitrogen gas at 420 can occur simultaneously with the supply of the precursor gas at 416, as described above with reference to Figure 3 As described. In one example, the second nitrogen gas co - flows at a flow rate less than the flow rate of the first nitrogen gas. In one example, the second nitrogen gas co - flows at a flow rate less than the flow rate of the first nitrogen gas but greater than the flow rate of the precursor gas. Optionally, the processing chamber is purged at 424.

[0049] At 428, method 400 (e.g., controller 204) determines whether the deposition process is complete. For example, method 400 determines whether a predetermined number of deposition cycles have been completed to achieve the desired deposition thickness. If true, method 400 ends. If false, method 400 proceeds to 404 to perform another deposition cycle.

[0050] The systems and methods of the present disclosure provide the following advantages. Generally, in the LFW deposition process, only a single nitrogen gas source is configured to be shared with the hydrogen gas and tungsten - containing precursor gas sources, which results in only one of the hydrogen gas or tungsten - containing precursor gas being supported to co - flow with nitrogen gas at each station (processing chamber). In contrast, in the systems and methods of the present disclosure, as described above, each station uses a dual - nitrogen gas source. During the LFW deposition process, both the hydrogen gas and tungsten - containing precursor gas flows have independent nitrogen gas flows. With this flexibility, different nitrogen gas flows can be used with the hydrogen gas and tungsten - containing precursor gas flows. Additionally, a higher nitrogen gas flow with the hydrogen gas flow and a lower nitrogen gas flow with the tungsten - containing precursor gas flow can significantly reduce sidewall roughness. This nitrogen gas flow can occupy surface binding sites and improve the surface mobility of the hydrogen - containing and / or tungsten - containing precursor gases. Thus, by providing the flexibility of co - flowing nitrogen gas with the hydrogen gas and / or tungsten - containing precursor gas flows simultaneously during the LFW nucleation and / or bulk fill deposition processes, and by independently controlling the co - flow of different nitrogen gas flows with the hydrogen gas and tungsten - containing precursor gas flows during these processes, the systems and methods of the present disclosure improve the tungsten sidewall roughness and fill performance in the LFW bulk fill deposition process.

[0051] The foregoing description is merely illustrative in nature and is not intended to limit the present disclosure, its application, or uses. The broad teachings of the present disclosure can be implemented in a variety of forms. Thus, while the present disclosure includes specific examples, the true scope of the present disclosure should not be so limited since other modifications will become apparent upon study of the drawings, the specification, and the appended claims. It should be understood that one or more steps in a method can be performed in a different order (or concurrently) without changing the principles of the present disclosure. In addition, although each implementation described above has certain features, any one or more of those features described for any implementation of the present disclosure can be implemented in and / or combined with the features of any other implementation, even if the combination is not explicitly described. In other words, the described implementations are not mutually exclusive, and the arrangement of one or more implementations with respect to each other is still within the scope of the present disclosure.

[0052] Spatial and functional relationships between elements (e.g., between modules, circuit elements, semiconductor layers, etc.) are described using various terms, including "connected," "engaged," "coupled," "adjacent," "next to," "on," "above," "below," and "disposed." Unless explicitly described as "direct," when the relationship between a first and a second element is described in the foregoing disclosure, the relationship can be a direct relationship, i.e., there are no other intermediate elements between the first and second elements, or an indirect relationship, i.e., there is one or more intermediate elements (spatially or functionally) between the first and second elements. As used herein, the phrase "at least one of A, B, and C" should be interpreted to mean a logical (A or B or C) using a non-exclusive logical "or," and should not be interpreted to mean "at least one of A, at least one of B, and at least one of C."

[0053] In some implementations, the controller is part of a system, which can be part of the foregoing examples. Such systems can include semiconductor processing equipment, including one or more processing tools, one or more chambers, one or more processing platforms, and / or specific processing components (wafer pedestals, gas flow systems, etc.). These systems can be integrated with electronics for controlling their operations before, during, and after processing of semiconductor wafers or substrates. The electronics can be referred to as a "controller," which can control various components or sub-parts of one or more systems. Depending on the processing requirements and / or the type of system, the controller can be programmed to control any process disclosed herein, including 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, position and operation settings, wafer in / out transfer tools and other transfer tools, and / or load locks connected to or interfacing with a particular system.

[0054] Broadly speaking, a controller can be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receives instructions, issues instructions, controls operations, enables cleaning operations, enables endpoint measurements, etc. The integrated circuits can include chips in the form of firmware that stores 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). The program instructions can be instructions communicated to the controller in the form of various individual settings (or program files) that define operating parameters for performing a specific process on or for a semiconductor wafer or system. In some embodiments, the operating parameters can be part of a recipe defined by a process engineer to complete 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.

[0055] In some embodiments, the controller can be part of a computer or coupled to a computer that is integrated with the system, coupled to the system, otherwise networked to the system, or a combination thereof. For example, the controller can be in the "cloud," or in all or part of a fab host computer system, thereby allowing remote access to wafer processing. The computer can enable remote access to the system to monitor the current progress of manufacturing operations, examine the history of past manufacturing operations, examine trends or performance metrics of multiple manufacturing operations, change the parameters of the current process, set processing steps to follow the current process, or initiate a new process. In some examples, a remote computer (e.g., a server) can provide a process recipe to the system via a network, which can include a local network or the Internet. The remote computer can include a user interface that allows the input or programming of parameters and / or settings, which are then transferred from the remote computer to the system. In some examples, the controller receives instructions in the form of data that specify the parameters for each processing step to be performed during one or more operations. It should be understood that the parameters can be specific to the type of process to be performed and the type of tool that the controller is configured to interface with or control. Thus, as described above, the controller can be distributed, for example, by including one or more discrete controllers networked together and working towards a common purpose, such as the processes and controls described herein. An example of a distributed controller for this purpose is one or more integrated circuits on a chamber that communicate with one or more integrated circuits located remotely (e.g., at the platform level or as part of a remote computer), and together they control the process on the chamber.

[0056] Non-limitingly, exemplary systems can include a plasma etch chamber or module, a deposition chamber or module, a spin rinse chamber or module, a metal electroplating chamber or module, a cleaning chamber or module, a bevel 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, an orbit chamber or module, and any other semiconductor processing system that may be associated with and / or used in the fabrication and / or production of semiconductor wafers.

[0057] As described above, depending on the process steps to be performed by the tool, the controller can communicate with one or more of the following: other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, neighboring tools, tools located throughout the factory, a host computer, another controller, or a materials transport tool that transports a wafer container to and from a tool location and / or a load port in a semiconductor manufacturing facility.

Claims

1. A gas delivery system for a processing chamber in a substrate processing system, the gas delivery system comprising: A first flow path coupled to a reducing gas source and configured to supply reducing gas from the reducing gas source to the processing chamber; A second flow path coupled to a precursor gas source and configured to supply precursor gas from the precursor gas source to the processing chamber; A third flow path coupled to a first nitrogen gas source and configured to co - flow first nitrogen from the first nitrogen gas source into the processing chamber while supplying the reducing gas to the processing chamber; and A fourth flow path coupled to a second nitrogen gas source and configured to co - flow second nitrogen from the second nitrogen gas source into the processing chamber while supplying the precursor gas to the processing chamber.

2. The gas delivery system according to claim 1, wherein the precursor gas is a tungsten - containing precursor gas.

3. The gas delivery system according to claim 2, wherein the precursor gas comprises WF 6 .

4. The gas delivery system according to claim 2, wherein the reducing gas comprises molecular hydrogen.

5. The gas delivery system according to claim 2, wherein the first nitrogen and the second nitrogen each comprise molecular nitrogen.

6. The gas delivery system according to claim 1, wherein the first flow path, the second flow path, the third flow path, and the fourth flow path each comprise at least one valve and a mass flow controller.

7. The gas delivery system according to claim 6, wherein: The first flow path comprises a first valve coupled to the reducing gas source, a first mass flow controller coupled to the first valve, and a first manifold coupled between the first mass flow controller and the processing chamber; The second flow path comprises a second valve coupled to the precursor gas source, a second mass flow controller coupled to the second valve, and a second manifold coupled between the second mass flow controller and the processing chamber; The third flow path comprises a third valve coupled to the first nitrogen gas source, a third mass flow controller coupled to the third valve, and a third manifold coupled between the third mass flow controller and the processing chamber; and The fourth flow path comprises a fourth valve coupled to the second nitrogen gas source, a fourth mass flow controller coupled to the fourth valve, and a fourth manifold coupled between the fourth mass flow controller and the processing chamber.

8. The gas delivery system according to claim 7, wherein: The third flow path is coupled to the first flow path between the first manifold and the processing chamber; and The fourth flow path is coupled to the second flow path between the second manifold and the processing chamber.

9. The gas delivery system according to claim 7, further comprising a controller configured to control the first valve, the second valve, the third valve, and the fourth valve, and the first mass flow controller, the second mass flow controller, the third mass flow controller, and the fourth mass flow controller, such that the first nitrogen co - flows into the processing chamber with the reducing gas, and the second nitrogen co - flows into the processing chamber with the precursor gas.

10. The gas delivery system according to claim 7, wherein: The precursor gas is a tungsten-containing precursor gas; the reducing gas contains molecular hydrogen; and the first nitrogen gas and the second nitrogen gas each contain molecular nitrogen.

11. The gas delivery system according to claim 10, wherein the processing chamber is configured to perform a low-fluorine tungsten deposition process.

12. The gas delivery system according to claim 11, wherein the tungsten-containing precursor gas comprises WF 6 .

13. The gas delivery system according to claim 9, wherein the controller is configured to control the gas delivery system such that the flow rate of the first nitrogen gas co-flowing with the reducing gas is greater than the flow rate of the second nitrogen gas co-flowing with the precursor gas.

14. A substrate processing system configured to perform a low-fluorine tungsten deposition process on a substrate disposed in a processing chamber, the substrate processing system comprising: a gas delivery system configured to supply to the processing chamber one of a tungsten-containing precursor gas, a reducing gas, a first nitrogen gas, and a second nitrogen gas; and a controller configured to perform a plurality of deposition cycles by controlling the gas delivery system, such that in each of the deposition cycles, the first nitrogen gas co-flows with the reducing gas in a first feed stage, and the second nitrogen gas co-flows with the precursor gas in a second feed stage.

15. The substrate processing system according to claim 14, wherein the controller is configured to control the gas delivery system such that the first nitrogen gas co-flows with the reducing gas at a first flow rate and the second nitrogen gas co-flows with the precursor gas at a second flow rate, and wherein the first flow rate is greater than the second flow rate.

16. The substrate processing system according to claim 15, wherein the controller is configured to control the gas delivery system such that the first nitrogen gas from a first nitrogen gas source co-flows and the second nitrogen gas from a second nitrogen gas source separated from the first nitrogen gas source co-flows.

17. The substrate processing system according to claim 14, wherein the controller is configured to control the gas delivery system to selectively purge the processing chamber between the first feed stage and the second feed stage.

18. The substrate processing system according to claim 14, wherein the controller is configured to control the gas delivery system such that the first nitrogen gas and the second nitrogen gas co-flow during one of nucleation layer deposition and bulk fill deposition of a tungsten-containing material.

19. The substrate processing system according to claim 14, wherein the precursor gas is WF 6 , the reducing gas is molecular hydrogen, and each of the first nitrogen gas and the second nitrogen gas is molecular nitrogen.

20. A method for performing a low-fluorine tungsten deposition process to deposit a tungsten-containing material on a substrate, the method comprising: supplying a reducing gas to a processing chamber containing the substrate in a first feed stage of a deposition cycle; while supplying the reducing gas to the processing chamber in the first feed stage, causing a first nitrogen gas to co-flow with the reducing gas, wherein causing the first nitrogen gas to co-flow includes supplying the first nitrogen gas from a first nitrogen gas source; supplying a tungsten-containing precursor gas to the processing chamber in a second feed stage of the deposition cycle following the first feed stage; and while supplying the tungsten-containing precursor gas to the processing chamber in the second feed stage, causing a second nitrogen gas to co-flow with the tungsten-containing precursor gas, wherein causing the second nitrogen gas to co-flow includes supplying the second nitrogen gas from a second nitrogen gas source separated from the first nitrogen gas source, Wherein the flow rate of the first nitrogen gas in the first feeding stage is greater than the flow rate of the second nitrogen gas in the second feeding stage.

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