Metal film deposition

Abstract

The present invention provides a method and apparatus for depositing metal. [Solution] This specification provides low-resistance metallization stack structures and related manufacturing methods for logic and memory applications. In some embodiments, a thin metal oxynitride or metal nitride nucleation layer is deposited thereafter, followed by the deposition of a pure metal conductor. The nucleation layer is amorphous and serves as a template for large pure metal film grain growth and low resistivity. Furthermore, certain embodiments of the methods described later convert almost all or all of the metal oxynitride nucleation layer into a pure metal layer to further reduce resistivity.

Description

[Background technology]

[0001] [References] A PCT request form is filed concurrently with this application as part of this application. Each application to which this application claims interest or priority, as identified in the concurrently filed PCT request form, is incorporated herein by reference in its entirety for all purposes.

[0002] Tungsten (W) film deposition using chemical vapor deposition (CVD) technology is an essential part of semiconductor manufacturing. For example, tungsten films can be used as low-resistance electrical connections in the form of horizontal interconnects, vias between adjacent metal layers, and contacts between a first metal layer on a silicon substrate and a device. Tungsten films can also be used in various memory applications (such as embedded word line (bWL) architectures for dynamic random access memory (DRAM) and word line formation for 3D NAND) and logic applications. However, the continuous decrease in feature size and film thickness presents various challenges, such as the high resistivity of thinner films. Other metals (such as molybdenum (Mo)) are being evaluated as low-resistivity alternatives to W.

[0003] The background art provided herein is intended to provide a general overview of the background to this disclosure. The works of the inventors named herein, to the extent described herein, are not considered prior art to this disclosure, either explicitly or implicitly, along with any manner of description that would not ordinarily be considered prior art at the time of filing. [Overview of the project]

[0004] One aspect of the present disclosure relates to a method for depositing a metal. The method comprises a step of depositing a first layer from a metal chloride precursor and ammonia using a first atomic layer deposition (ALD) process. The method further comprises a step of depositing an elemental metal layer on the preceding first layer from a metal chloride precursor and hydrogen using a second ALD process.

[0005] The examples may include one or more of the following features: In the method, the first layer is a metal oxynitride layer or a metal nitride layer. In the method, the first layer is converted to an elemental metal layer during or before the second ALD treatment. In the method, the converted elemental metal layer contains less than 1 (atomic)% impurities. In the method, the first layer is an amorphous layer. In the method, the elemental layer is crystalline. In the method, the first and second ALD treatments are performed in the same chamber without exposure to air. In the method, the first layer is a template for metal particle growth in the second layer. In the method, the elemental layer contains less than 1 (atomic)% impurities. In the method, the elemental metal layer is elemental tungsten. In the method, the elemental metal layer is elemental molybdenum. In the method, the first layer is either molybdenum oxynitride or molybdenum nitride. In the method, the first ALD treatment is performed at a temperature lower than 400°C. In the method, the second ALD treatment is carried out at a temperature higher than 400°C. In the method, the deposition of the first layer and the deposition of the elemental layer are carried out in the same chamber. In the method, the deposition of the first layer and the deposition of the elemental layer are carried out in different stations within the same chamber. In the method, the deposition of the first layer is carried out in the first chamber, and the deposition of the elemental layer is carried out in the second chamber. The method further comprises the step of exposing the first layer to air before the deposition of the elemental layer.

[0006] Another aspect of the present disclosure relates to an apparatus comprising first and second processing chambers, each configured to house a substrate; a substrate support within each processing chamber; a gas inlet configured to direct a gas into each processing chamber; a heater configured to heat the substrate support within each processing chamber; and a controller having program instructions. The apparatus further includes sequentially introducing a metal chloride precursor and ammonia into the first processing chamber while the substrate is housed in the first processing chamber. The apparatus further includes, after (a), transferring the substrate to the second processing chamber. The apparatus further includes, after (b), sequentially introducing a metal chloride precursor and hydrogen into the second processing chamber while the substrate is housed in the second processing chamber.

[0007] Another aspect of the present disclosure relates to an apparatus, the apparatus comprising: a processing chamber having one or more stations, each configured to accommodate a substrate; a substrate support in each of the one or more stations; a gas inlet configured to direct a gas into each of the one or more stations; a heater configured to heat the substrate support in each station; and a controller, the controller comprising: program instructions for sequentially introducing a metal chloride precursor and ammonia into one of the one or more stations; and program instructions for sequentially introducing a metal chloride precursor and hydrogen into one of the one or more stations.

[0008] These embodiments and other embodiments will be described in more detail below with reference to the drawings. [Brief explanation of the drawing]

[0009] [Figure 1A] A schematic example of a material stack including a nucleation layer as a template for metal growth. [Figure 1B] A schematic example of a material stack including a nucleation layer as a template for metal growth.

[0010] [Figure 2] A figure providing an example of a structure in which a material stack can be used according to an embodiment. [Figure 3A] A figure providing an example of a structure in which a material stack can be used according to an embodiment. [Figure 3B] A figure providing an example of a structure in which a material stack can be used according to an embodiment.

[0011] [Figure 4] A process flowchart illustrating the steps of a method for depositing conductive material according to various embodiments.

[0012] [Figure 5] This figure shows the growth rate of atomic layer deposition of a molybdenum-containing layer on a dielectric surface using an ammonia reducing agent and a molybdenum acid chloride precursor.

[0013] [Figure 6] This figure illustrates molybdenum growth from hydrogen and molybdenum acid chloride onto a nucleation layer deposited on a dielectric surface, as described herein, compared to direct molybdenum growth from hydrogen and molybdenum acid chloride onto a dielectric surface.

[0014] [Figure 7] A graph showing the resistivity of a molybdenum film deposited on titanium nitride as described herein, compared to a molybdenum film deposited on titanium nitride.

[0015] [Figure 8] A block diagram showing a processing system suitable for performing a vapor deposition process according to the embodiments described herein. [Modes for carrying out the invention]

[0016] In the following description, numerous specific details are set forth in order to provide a thorough understanding of the presented embodiments. The disclosed embodiments may be practiced without some or all of these specific details. Also, in order to avoid obscuring the disclosed embodiments needlessly, detailed descriptions of well-known processing operations are omitted. It is to be understood that the disclosed embodiments are described in relation to specific embodiments, but are not intended to be limiting.

[0017] This specification provides a low-resistance metallization stack structure and related manufacturing methods for logic and memory applications. In some embodiments, a thin metal oxynitride or metal nitride nucleation layer is deposited, followed by the deposition of a pure metal conductor. The nucleation layer is amorphous and serves as a template for large pure metal film grain growth and low resistivity. Further, certain embodiments of the methods described hereinafter convert most or all of the metal oxynitride nucleation layer to a pure metal layer, further reducing the resistivity.

[0018] According to various embodiments, one or more advantages may be realized. In some embodiments, the direct deposition of a metal (such as Mo) onto aluminum oxide and other dielectrics may be performed. In some embodiments, these depositions may be performed at temperatures below 500 °C or even below 400 °C without significant nucleation delay. Deposition at low temperatures may lead to better step coverage. In various embodiments, a lower resistivity film can be obtained from a film with large grain size and / or a film can be deposited directly onto a dielectric without a high resistivity film such as titanium nitride (TiN). The addition of a low-temperature metal nitride nucleation layer may enable subsequent pure metal deposition at temperatures below 600 °C or even below 500 °C. This can make the metal (nitride) + pure metal nucleation stack suitable for semiconductor applications having a thermal history of 600 °C or 500 °C or less for wafer processing. This enables the deposition of metals at temperatures inaccessible to pure films without a high resistivity layer such as TiN. For example, the temperature for ALD of pure Mo can exceed 600 °C when deposited directly onto a dielectric.

[0019] Figures 1A and 1B are schematic examples of a material stack including a nucleation layer as a template for metal growth. Figures 1A and 1B show the order of materials in a particular stack and may be used in any suitable architecture and application, as will be described in detail later with respect to FIGS. 2, 3A, and 3B. In the example of FIG. 1A, a substrate 102 has a nucleation layer 108 deposited thereon. The substrate 102 may be a silicon or other semiconductor wafer, such as a 200 mm wafer, a 300 mm wafer, or a 450 mm wafer, and may include a wafer having one or more material layers, such as a dielectric material, a conductive material, or a semiconductor material, deposited thereon. The method may also be applied to form a metallization stack structure on other substrates (such as glass, plastic, etc.).

[0020] In FIG. 1A, a dielectric layer 104 is on the substrate 102. The dielectric layer 104 may be deposited directly on the semiconductor (e.g., Si) surface of the substrate 102, or any number of intermediate layers may be present. Examples of dielectric layers include doped and undoped silicon oxide, silicon nitride, and aluminum oxide layers, and specific examples include doped or undoped layers SiO2 and Al2O3. Also, in FIG. 1A, a diffusion barrier layer 106 is disposed between the nucleation layer 108 and the dielectric layer 104. Examples of diffusion barrier layers include titanium nitride (TiN), titanium / titanium nitride (Ti / TiN), tungsten nitride (WN), and tungsten carbonitride (WCN). A metal layer 110 is deposited on the nucleation layer 108 and is the main conductor (also referred to as the bulk conductor or bulk layer) of the structure together with the nucleation layer 108 that provides a template for metal growth.

[0021] As will be described in detail later, the nucleation layer 108 is deposited as an amorphous film. By using an amorphous film having large particles as a template for metal growth, a metal having large particles and a low resistivity can be formed. Examples of metal layers include a tungsten (W) layer and a molybdenum (Mo) layer.

[0022] Figure 1B shows another example of a material stack. In this example, the stack comprises a substrate 102, a dielectric layer 104, and a nucleation layer 108 deposited directly on the dielectric layer 104, with no diffusion barrier layer in between. As in the example in Figure 1A, a metal layer 110 is deposited on the nucleation layer 108 and is the dominant component of the structure.

[0023] In the examples in Figures 1A and 1B, the nucleating layer 108 may be deposited as a metallic oxynitride layer (e.g., a layer of tungsten oxynitride or molybdenum oxynitride). However, during subsequent processing, in certain embodiments, all or most of the nucleating layer 108 may be converted to pure metal. Thus, according to various embodiments, the nucleating layer 108 may or may not have the same composition as the pure metal layer 110. The nucleating layer 108 may be characterized by amorphousness, and the pure metal layer 110 may be characterized by a large grain size.

[0024] In some embodiments, the metal of the metal oxynitride layer is the same as the metal of the pure metal conductor. For example, a molybdenum oxynitride layer may be deposited as a nucleating layer before the molybdenum layer is deposited, and a tungsten oxynitride layer may be deposited as a nucleating layer before the tungsten layer is deposited. In another embodiment, the metal oxynitride layer may have a different metal than the metal of the pure metal conductor. For example, a tungsten layer may be deposited on a molybdenum-containing nucleating layer, and a molybdenum layer may be deposited on a tungsten-containing nucleating layer.

[0025] Figures 1A and 1B show examples of metallization stacks, but the methods and resulting stacks are not limited thereto. For example, in some embodiments, the nucleation layer may be deposited directly onto a Si or other semiconductor substrate as a template for metal growth. Furthermore, while the growth of tungsten (W) or molybdenum (Mo) on the nucleation layer has been described above, the nucleation layer may also serve as a template for the low-resistivity growth of other metals (such as cobalt (Co), ruthenium (Ru), nickel (Ni)), and alloys containing these metals (such as MoW). Moreover, the nucleation layer may be a layer of any suitable metal oxynitride or metal nitride, such as molybdenum oxynitride, molybdenum nitride, tungsten oxynitride, tungsten nitride, or nickel nitride.

[0026] The material stack described above and further explained below may be implemented in various structures. Figures 2, 3A, and 3B provide examples of structures in which the stack may be used. Figure 2 shows a schematic example of a DRAM architecture with embedded word lines (bWLs) 210 in a silicon substrate 202. The bWLs 210 are formed in trenches etched into the silicon substrate 202. The trenches are lined with a conformal nucleation layer 208 and an insulating layer 204 placed between the conformal nucleation layer 208 and the silicon substrate 202. In the example of Figure 2, the insulating layer 204 may be a gate oxide layer formed from a high-k material (such as silicon oxide or silicon nitride material). In some embodiments, a conformal barrier layer, such as a TiN or tungsten-containing layer, may be sandwiched between the nucleation layer 208 and the insulating layer 204.

[0027] Figure 3A shows a schematic example of a word line 310 within a 3D NAND structure 323. The word line 310 is separated by an oxide layer 311. Figure 3B shows details of the boundary between the word line 310 and the oxide layer 311, including an aluminum oxide (Al2O3) layer 304 and a nucleation layer 308. In some embodiments, the nucleation layer 308 may be deposited directly on the oxide layer 311 or on TiN or other barrier layers, as described herein. The nucleation layer may be between about 10 Å and 100 Å or between 10 Å and 50 Å for the deposition of a word line 310 with a thickness between about 10 nm and 100 nm.

[0028] Figure 4 is a process flowchart showing the steps of a method for depositing a conductive material. In step 402, a conformal nucleation layer is formed on the structure by atomic layer deposition (ALD). In the ALD method, the substrate is exposed in a cycle such that the substrate is first exposed to pulses of a suitable metal-containing precursor, then the precursor is optionally purged, then the substrate is exposed to pulses of a reducing agent, then the reducing agent is optionally purged, and such cycles may be repeated until a nucleation layer of the desired thickness is formed for the substrate. It is understood that the order of the precursor and reducing agent may be reversed such that the sequence starts with a dose of the reducing agent followed by a dose of the metal-containing precursor.

[0029] In some embodiments, the reducing agent is ammonia (NH3) or other nitrogen-containing reducing agents (such as hydrazine (N2H4)). Chemisorption of NH3 onto the dielectric is more likely than that of hydrogen (H2). In some embodiments, the reducing agent and precursor are selected to react without dissociation of the reducing agent. NH3 reacts with metal acid chlorides and metal chlorides without dissociation. This is in contrast to ALD from metal acid chlorides using H2 as the reducing agent, for example, in the latter case, where H2 dissociates on the surface to form adsorbed hydrogen atoms, resulting in very low concentrations of the reactant species and low surface coverage during the initial nucleation of the metal on the dielectric surface. By using NH3 and a metal acid chloride or metal chloride precursor, the delay in nucleation is reduced or eliminated at deposition temperatures up to several hundred degrees, which are lower than those used by H2 reduction of the same metal precursor.

[0030] In some embodiments, the reducing agent may be a boron-containing or silicon-containing reducing agent, such as diborane (B2H6) or (SiH4). These reducing agents may be used together with a metal chloride precursor or a metal acid chloride. B2H6 and SiH4 react with water, which is formed as a byproduct during the ALD process, to form B2O3 and SiO2, which are insulating and remain in the film, increasing the resistivity. Furthermore, the use of NH3 improves adhesion to certain surfaces containing Al2O3 compared to ALD with B2H6 and SiH4.

[0031] Examples of metal chlorides and metal chloride precursors include molybdenum pentachloride (MoCl5), molybdate chlorides (such as molybdenum dichloride (MoO2Cl2) and molybdenum tetrachloride (MoOCl4)), tungsten pentachloride (WCl5), tungsten hexachloride (WCl6), tungsten tetrachloride (WCl4), tungsten dichloride (WCl2), and tungstate chlorides (WO2Cl2). x Cl y It contains (such as tungsten tetrachloride (WOCl4)).

[0032] Metal chlorides and metal acid chlorides may be useful in embodiments where fluorine contamination is a concern. However, in some embodiments, fluorine-containing precursors may be used. These include metal fluorides such as tungsten hexafluoride (WF6), molybdenum hexafluoride (MoF6), and molybdenum pentafluoride (MoF5).

[0033] The resulting nucleation layer is generally not a pure elemental film, but rather a film of metal nitride or metal oxynitride. In some embodiments, residual chlorine or fluorine may be present from the deposition, particularly when deposition is performed at low temperatures. In some embodiments, the residual chlorine or fluorine is present in only trace amounts. In some embodiments, the nucleation layer is an amorphous layer. Impurities in the film (e.g., oxygen, NH3, chlorine, or other halogens) promote the growth of amorphous microstructures. In some embodiments, the as-deposited nucleation layer is an amorphous metal oxynitride layer or amorphous metal nitride layer. Amorphousness serves as a template for large grain growth in conductors that are subsequently deposited. The surface energy of the nitride or oxynitride relative to the oxide surface is far more favorable than the surface energy of the metal on the oxide surface, facilitating the formation of a continuous and smooth film on the dielectric. This allows for the formation of thin, continuous layers. Examples of nucleation film thicknesses range from 5 to 30 Å immediately after deposition. Depending on the temperature, this can be, for example, about 5 to 50 ALD cycles.

[0034] As will be discussed later, during subsequent processing, the nucleation layer may be converted into a pure (or less impure) elemental metal film, resulting in a reduction in thickness.

[0035] The substrate temperature for nucleation layer deposition may be, for example, in the range of 300°C to 600°C. In some embodiments, lower temperatures may be used. Such temperatures may be less than 500°C, less than 550°C, less than 450°C, less than 400°C, or less than 350°C. Lower temperatures may be used to improve step coverage. Furthermore, lower temperatures can increase the amount of impurities in the nucleation layer and increase amorphousness, which in turn can increase the particle size of the conductor deposited later.

[0036] The surface on which the nucleation layer is deposited depends on the specific application. In some embodiments, the nucleation layer is deposited directly onto a dielectric surface (e.g., silicon oxide, aluminum oxide, silicon nitride, etc.). In some embodiments, the nucleation layer is deposited directly onto titanium nitride or other surfaces. As will be detailed later, subsequent elemental metal deposition may be performed on any surface by performing step 402.

[0037] After the deposition of the nucleation layer, an optional step 404 may be performed. In step 404, an ALD cycle is performed at a lower temperature for the metal conductor and the reducing agent. "Lower" temperature means that the temperature of step 404, if performed, is lower than that of the subsequent step 406. Examples of temperatures may be less than 500°C, less than 550°C, less than 450°C, less than 400°C, or less than 350°C. In this step, the reducing agent may differ from that in step 402, and in particular, an example may be hydrogen (H2). In particular, H2 can lead to the deposition of an elemental film with significantly fewer impurities than the nucleation layer. The temperature may be the same as that used in step 402 in some embodiments. The metal precursor may also be the same or a different precursor as that used in step 402. In some embodiments, the same precursor is used, and only the reducing agent is changed. In some embodiments, step 404 may facilitate the conversion of the nucleation layer of metal nitride or metal oxynitride to an elemental metal film. According to various embodiments, step 404 may or may not deposit a considerable amount of principal film.

[0038] In a further optional step 406, the substrate temperature is increased. In embodiments where step 404 is performed, step 406 is also performed. In other embodiments, operation 406 may be performed. For example, if the nucleation layer deposition is performed at a relatively low temperature (e.g., below 400°C), in operation 406 the temperature may be increased to a higher temperature in which the lead material is deposited. In some embodiments, the temperature may be higher than 500°C, and in some embodiments, it may be higher than 600°C. In some embodiments, a lower temperature (e.g., between 400°C and 500°C, including both ends) may be used for bulk deposition. The temperature may or may not be increased depending on the temperature of the previous step.

[0039] The method may then proceed to step 408, in which the lead material is deposited by ALD (from any of steps 402, 404, or 406). As in step 404 (if performed), H2 may be used as a reducing agent.

[0040] Examples of metal chlorides and metal chloride precursors that may be used in steps 404 and 408 include molybdenum pentachloride (MoCl5) and molybdenum hexachloride (MoCl6), molybdate chlorides (such as molybdenum dichloride (MoO2Cl2) and molybdenum tetrachloride (MoOCl4)), tungsten pentachloride (WCl5), tungsten hexachloride (WCl6), tungsten tetrachloride (WCl4), tungsten dichloride (WCl2), and tungstate chlorides (WO2Cl2). x Cl y It contains (such as tungsten tetrachloride (WOCl4)).

[0041] During one or more of steps 404–408, the nucleating layer is converted into an elemental metal layer. This may also be characterized as the removal of impurities (i.e., any non-metallic components). The nucleating layer may contain more impurities than the elemental layer that is later deposited, but the impurities are removed sufficiently so that the resistivity of the stack is the same as or equivalent to that of a stack without the nucleating layer. The thickness is also reduced, for example, a 30 Å film immediately after deposition may contribute to the stack as approximately 10 Å of metal.

[0042] According to various embodiments, one or more of the following may be used to facilitate the conversion of the nucleating layer to an elemental metal film: 1) depositing the bulk conductor at a higher temperature (e.g., 550°C) than in which the nucleating layer is deposited; 2) performing a lower-temperature ALD H2 / metal precursor cycle, as described with reference to step 404 above; and 3) in-situ depositing the bulk layer so that the nucleating layer is not exposed to air or oxidized in any other way before bulk deposition. Mo acid chlorides and W acid chlorides are particularly readily converted to elemental metals. The resulting converted nucleating layer and pure metal layer may each be characterized as having atomic impurities of 1% or less.

[0043] Figure 5 shows the results of forming a Mo-containing layer using an NH3 reducing agent and a molybdenum acid chloride precursor to form a nucleation layer, followed by the conversion of the Mo-containing layer to Mo as described above. Figure 5 shows the thickness of the nucleation layer after conversion to Mo as a function of the ALD cycle. Deposition was performed on three different surfaces (Al2O3 surface, TiN surface, and thermal SiO2 surface) at each temperature (350°C - low temperature, 400°C - medium temperature, 450°C - high temperature). At each temperature, the growth rate was the same on all surfaces. Therefore, the growth rate is not affected by temperature and not by the substrate surface. In particular, this differs from other deposition systems that can be highly substrate-dependent. For example, ALD deposition with H2 and molybdenum acid chloride involves deposition on TiN, a small amount on SiO2, and almost nothing on Al2O3.

[0044] Figure 6 shows the subsequent growth of Mo by the ALD cycle of H2 and molybdenum acid chloride on a nucleation layer deposited on an Al2O3 surface, compared to direct Mo growth by the ALD cycle of H2 and molybdenum acid chloride on an Al2O3 surface at 550°C. Curve A shows the growth of Mo on a nucleation layer of approximately 10 Å deposited from NH3 / Mo acid chloride, and curve B shows the growth of Mo on Al2O3. As can be seen from the figure, ALD deposition from H2 reduction of the Mo precursor shows stable growth on the Mo nucleation layer deposited from NH3 reduction of the Mo precursor, with no delay in nucleation. In contrast, the ALD cycle with the H2 / Mo precursor results in no deposition on Al2O3.

[0045] Figure 7 shows the resistivity of various Mo films. Curve A shows the resistivity of an ALD film made of H2 / Mo acid chloride on a nucleation layer made of NH3 / Mo acid chloride at low temperature, curve B shows the resistivity of an ALD film made of H2 / Mo acid chloride on a nucleation layer made of NH3 / Mo acid chloride at high temperature, and curve C shows the resistivity of an ALD film made of H2 / Mo acid chloride on TiN. When the nucleation layer described herein is used, no increase in blanket resistivity is observed, suggesting that the nucleation layer is converted into an elemental Mo film.

[0046] Although the above description refers to metal acid chlorides and metal chloride precursors, the method may also be carried out with other halogen-containing precursors, such as metal acid fluorides and metal fluoride precursors.

[0047] In some embodiments, the method may include a step of depositing a pure metal layer by chemical vapor deposition (CVD) after depositing a metal oxynitride or metal nitride nucleating layer.

[0048] Device The disclosed embodiments can be carried out using any suitable chamber. Examples of deposition systems include, for example, the ALTUS® and ALTUS® Max from Lam Research, Inc. of Fremont, California, or any of the various other commercially available processing systems. Processing can be carried out in parallel at multiple deposition stations.

[0049] In some embodiments, the nucleation layer deposition process is performed in a first station, which is one of 2, 5, or more deposition stations arranged within a single deposition chamber. For example, nucleation layer deposition is performed in the first station, followed by low-temperature hydrogen reduction of the metal precursor in a second station, and then high-temperature hydrogen reduction of the metal precursor in a third station. Each station may have independent temperature control. In some embodiments, different steps of the process are performed in two different stations of the deposition chamber. For example, a substrate may be exposed to NH3 in the first station using individual gas supply systems that form a local atmosphere on the substrate surface, and then the substrate is transferred to the second station and exposed to a precursor of a metal chloride, metal fluoride, or metal acid chloride for deposition of a nucleation layer. In some embodiments, the substrate may then be returned to the first station for a second exposure to NH3. The substrate may then be transferred to the second station for exposure to the metal precursor. After the deposition of the first metal chloride or metal acid chloride, the substrate may be exposed to NH3 in another station. This may be repeated as needed to complete nucleation layer deposition and proceed with bulk layer deposition at the same or different stations.

[0050] In some embodiments, multiple chambers are used to carry out the method described herein. For example, the deposition of a nucleating layer may be carried out in a first chamber and the deposition of a bulk metal layer may be carried out in a second chamber. The two chambers may be connected to a common vacuum chamber so that the substrate can be transferred between them without exposure. In other embodiments, the chambers are not connected under vacuum, and the substrate is exposed to air during transfer. Any oxidation may be reduced in subsequent processing as described above.

[0051] Figure 8 is a block diagram showing a processing system suitable for performing a deposition process according to the embodiments described herein. The system 800 comprises a transport module 803. The transport module 803 provides a clean pressurized environment to minimize the risk of contamination when the substrate being processed is moved between various reactor modules. A multi-station reactor 809 capable of performing ALD deposition as described herein is mounted on the transport module 803. The chamber 809 may comprise a plurality of stations 811, 813, 815, and 817 capable of performing these operations sequentially. For example, the chamber 809 may be configured such that stations 811 and 813 perform nucleation layer deposition and stations 813 and 815 perform bulk layer deposition. Each deposition station may comprise a heated wafer pedestal and a showerhead, diffusion plate, or other gas inlet.

[0052] Also, one or more single - station modules or multi - station modules 807 capable of performing plasma pre - cleaning or chemical (non - plasma) pre - cleaning may be mounted on the transfer module 803. The modules may be used for various other processes (e.g., immersion in a reducing agent). The system 800 also includes one or more (two in this example) wafer source modules 801 in which wafers are housed before and after processing. An atmospheric robot (not shown) in the atmospheric transfer chamber 819 first removes the wafer from the source module 801 to the load lock 821. A wafer transfer device (generally, a robot arm unit) in the transfer module 1103 moves the wafer from the load lock 821 to the module mounted on the transfer module 803 and between the modules.

[0053] In some embodiments, a high - temperature showerhead is used. This enables the use of a single - plenum rather than a dual - plenum showerhead. By maintaining the wetted surface inside the showerhead at 150 °C or above 200 °C, NH3 and metal oxynitride or metal chloride precursors can be used with a single - plenum showerhead without condensation of NH4Cl. Alternatively, a dual - plenum showerhead may be used where NH3 is supplied through one plenum and the metal chloride or metal oxychloride precursor is supplied through the other plenum.

[0054] As described above, in some embodiments, depositing both metal (nitride) nucleation and pure metal in a single processing chamber involves high - temperature reactions of H2, metal (oxychloride), and their by - products (HCl, OCl x , metal - Cl x , ···) resulting in metal + O immediately after deposition x + NH x + Cl xThis facilitates the conversion of the nucleated film to pure metal. This may be done in a multi-station reactor, as described above, at a low temperature in the first deposition station and at a high temperature in subsequent deposition stations. In some embodiments, individual deposition stations in a multi-station deposition reactor may be separated from each other by shaping showerheads and pedestals such that, in a raised processing position, the two assemblies form a small processing space above the wafer and a very narrow gap to separate the processing space from the main chamber. The narrow gap at the edge of the processing space may be reinforced with an inert gas purge barrier to make it difficult for gases to diffuse from the main chamber into the processing space. The narrow gap at the edge of the processing space may also incorporate a localized pumping plenum to prevent processing gases from entering the main chamber. This eliminates the risk of deposition or particle formation occurring in the main chamber. The narrow edge gap itself eliminates the risk of gases from the main chamber diffusing back into the wafer processing space, thus preventing mutual interference between stations.

[0055] As described above, in certain embodiments, the system comprises two different deposition chambers. For example, referring to Figure 8, two deposition chambers may be attached to the transport module 803. In such embodiments, each deposition chamber may be a single or multi-station chamber. Furthermore, two chambers that are not under a common vacuum may be used.

[0056] In certain embodiments, a system controller 829 is used to control processing conditions during deposition. The controller typically comprises one or more memory devices and one or more processors. The processor may include a CPU or computer, analog and / or digital input / output connections, a stepper motor controller board, and the like.

[0057] The controller may control all aspects of the operation of the deposition apparatus. The system controller runs system control software that includes a set of instructions for controlling timing, gas mixing, chamber pressure, chamber temperature, wafer temperature, radio frequency (RF) power level (if used), wafer chuck or pedestal position, and other parameters of a particular process. In some embodiments, other computer programs stored in a memory device associated with the controller may be used.

[0058] Typically, a user interface exists associated with the controller. This user interface may include a display screen (a graphical software display of the device and / or processing conditions) and user input devices such as a pointing device, keyboard, touchscreen, or microphone.

[0059] The system control logic may be configured in any suitable manner. Generally, the logic may be designed or configured in hardware and / or software. Instructions for controlling the drive circuits may be hardcoded or provided as software. Instructions may be provided by “programming.” Such programming is understood to include any form of logic, such as hardcoded logic in digital signal processors, application-specific integrated circuits, and other devices with specific algorithms implemented as hardware. Programming is also understood to include software instructions or firmware instructions that can be executed on a general-purpose processor. The system control software may be coded in any suitable computer-readable programming language. Alternatively, the control logic may be hardcoded in the controller. For these purposes, application-specific integrated circuits, programmable logic devices (e.g., field-programmable gate arrays, i.e., FPGAs), etc., may be used. Where “software” or “code” is used below, functionally equivalent hardcoded logic may be used instead.

[0060] Computer program code for controlling the vapor deposition process and other processes within the processing procedure can be written in any conventional computer-readable programming language, such as assembly language, C, C++, Pascal, or Fortran. The compiled object code or script is executed by the processor to perform the tasks specified within the program.

[0061] Controller parameters relate to processing conditions such as the composition and flow rate of the processing gas, temperature, pressure, cooling gas pressure, and chamber wall temperature. These parameters are provided to the user in the form of a recipe and can be entered using a user interface.

[0062] Signals for monitoring the process may be provided by the analog and / or digital input connections of the system controller. Signals for controlling the process are output from the analog and digital output connections of the deposition apparatus.

[0063] System software can be designed or configured in many different ways. For example, various chamber component subroutines or control objects may be written to control the operation of the chamber components necessary to perform the deposition process described herein. Examples of programs or program sections for this purpose include substrate placement code, processing gas control code, pressure control code, and heater control code.

[0064] In some embodiments, the controller 829 is part of a system, and the system may be part of the examples described above. Such a system may comprise a semiconductor processing apparatus, including one or more processing tools, one or more chambers, one or more platforms for processing, and / or specific processing components (such as a wafer pedestal, a gas flow system, etc.). These systems may be integrated with electronic equipment for controlling the operation of the system before, during, and after processing of semiconductor wafers or substrates. The electronic equipment may be referred to as a “controller,” and may control various components or sub-components of the system. Depending on the processing requirements and / or the type of system, the controller 829 may be programmed to control any of the processing disclosed herein, such as supplying processing gases, setting temperature (e.g., heating and / or cooling), setting pressure, setting vacuum, setting power, setting radio frequency (RF) generator settings in some systems, setting RF matching circuit settings, setting frequency, setting flow rate, setting fluid supply, setting position and operation, and moving wafers in and out of load locks connected to or coupled with tools and other moving tools and / or specific systems.

[0065] Generally, a controller may be defined as an electronic device having various integrated circuits, logic, memory, and / or software that receive instructions, issue instructions, control operations, enable cleaning operations, enable endpoint measurements, etc. Integrated circuits may include chips in the form of firmware that store program instructions, chips defined as digital signal processors (DSPs), 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 that are communicated to the controller in the form of various individual settings (or program files) and define operating parameters for performing specific operations on or for semiconductor wafers, or operating parameters to the system. In some embodiments, operating parameters may be part of a recipe defined by a processing engineer to achieve one or more processing steps during the processing of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or dies of a wafer.

[0066] In some embodiments, the controller 829 may be part of a computer integrated with the system, connected to the system, networked with the system in other ways, or a combination thereof, or connected to such a computer. For example, the controller 829 may be in the “cloud” or may be all or part of a fab host computer system that enables remote access to wafer processing. The computer may enable remote access to the system to monitor the current progress of a manufacturing operation, examine the history of past manufacturing operations, or examine trends or performance metrics from multiple manufacturing operations, in order to change the parameters of the current operation, set up processing steps according to the current operation, or start a new operation. In some examples, a remote computer (e.g., a server) may provide processing recipes to the system via a network (which may include a local network or the internet). The remote computer may have a user interface that enables input or programming of parameters and / or settings, which are communicated from the remote computer to the system. In some examples, the controller receives instructions in the form of data, which specify parameters for each of the processing steps performed during one or more operations. It should be understood that the parameters may be specific to the type of processing to be performed and the type of tools the controller is configured to interface with or control. Therefore, as described above, the controller may be distributed, for example, by comprising one or more separate controllers networked and operating toward a common purpose (such as the processing and control described herein). An example of a distributed controller for such a purpose is one or more integrated circuits on a chamber communicating with one or more remotely located integrated circuits (such as those at the platform level or as part of a remote computer) that cooperate to control the processing in the chamber.

[0067] Examples of systems, though not limited to them, may include plasma etching chambers or modules, deposition chambers or modules, spin rinse chambers or modules, metal plating chambers or modules, cleaning chambers or modules, bevel edge etching chambers or modules, physical vapor deposition (PVD) chambers or modules, CVD chambers or modules, ALD chambers or modules, atomic layer etching (ALE) chambers or modules, ion implantation chambers or modules, track chambers or modules, and any other semiconductor processing systems that may be related to or used in the processing and / or manufacturing of semiconductor wafers.

[0068] As described above, depending on the one or more processing steps performed by the tool, the controller may communicate with one or more of the following: other tool circuits or modules, other tool components, cluster tools, other tool interfaces, adjacent tools, nearby tools, tools located throughout the factory, the main computer, another controller, or tools used for material transport to and from the tool locations and / or load ports within the semiconductor manufacturing plant.

[0069] The controller 829 may include various programs. A substrate placement program may include program code for controlling chamber components used to load a substrate onto a pedestal or chuck and to control the spacing between the substrate and other components of the chamber (such as gas inlets and / or gas targets). A processing gas control program may include code for controlling the gas composition and flow rate, and optionally for flowing gas into the chamber before deposition to stabilize the pressure inside the chamber. A pressure control program may include code for controlling the pressure inside the chamber, for example, by adjusting the throttle valve of the chamber's exhaust system. A heater control program may include code for controlling the current to a heating unit used to heat the substrate. Alternatively, the heater control program may control the supply of a heat conduction gas (such as helium) to the wafer chuck.

[0070] Examples of chamber sensors that may be monitored during deposition include mass flow controllers, pressure sensors (such as manometers), and thermocouples placed in the pedestal or chuck. Appropriately programmed feedback and control algorithms may be used in conjunction with data from these sensors to maintain desired processing conditions.

[0071] The above describes the implementation of embodiments of the present disclosure in single-chamber or multi-chamber semiconductor processing tools.

[0072] The above describes the implementation of the disclosed embodiments in single-chamber or multi-chamber semiconductor processing tools. The apparatus and processes described herein may be used together with lithography patterning tools or processes for processing or manufacturing, for example, semiconductor devices, displays, LEDs, photovoltaic panels, etc. Typically, but not always, such tools / processes are used or performed together in a common manufacturing facility. Thin film lithography patterning typically involves some or all of the following steps, each provided by a number of possible tools: (1) applying a photoresist onto a workpiece (i.e., a substrate) using a spin-on or spray-on tool; (2) curing the photoresist using a hot plate or furnace or a UV curing tool; (3) exposing the photoresist to visible light or UV or X-rays using a tool such as a wafer stepper; (4) developing the resist for patterning by selectively removing the resist using a tool such as a wet bench; (5) transferring the resist pattern to the underlying film or workpiece using a dry etching tool or a plasma-assisted etching tool; and (6) removing the resist using a tool such as an RF plasma or microwave plasma resist stripper.

[0073] In the above description and claims, numerical ranges include the endpoints of the range. For example, "thickness between 1 and 5 nm" includes 1 nm and 5 nm. Similarly, ranges represented by dashes include the endpoints of the range.

[0074] knot For the sake of understanding, this embodiment has been described in some detail, but it is clear that some modifications and variations may be made within the scope of the appended claims. It should be noted that many other ways of carrying out the processes, systems, and apparatus of the present invention exist. Therefore, this embodiment is considered illustrative and not limiting, and embodiments are not limited to the details shown herein.

Claims

1. It is a method, A process of depositing a first layer from a metal acid chloride precursor and ammonia using first atomic layer deposition (ALD) treatment, A step of depositing an elemental metal layer onto the first layer from a metal chloride precursor and hydrogen using a second ALD treatment, A method that includes [a certain feature].

2. A method according to claim 1, wherein the first layer is a metal oxynitride layer or a metal nitride layer.

3. A method according to claim 2, wherein the first layer is converted into an elemental metal layer during or before the second ALD treatment.

4. A method according to claim 3, wherein the converted elemental metal layer contains less than 1 (atomic) percent of impurities.

5. A method according to claim 1, wherein the first layer is an amorphous layer.

6. A method according to claim 5, wherein the element layer is crystalline.

7. A method according to claim 1, wherein the first and second ALD treatments are performed in the same chamber without exposure to air.

8. A method according to claim 1, wherein the first layer is a template for growing metal particles in the second layer.

9. A method according to claim 1, wherein the element layer contains less than 1 (atomic) percent of impurities.

10. A method according to claim 1, wherein the elemental metal layer is elemental tungsten.

11. A method according to claim 1, wherein the elemental metal layer is elemental molybdenum.

12. A method according to claim 1, wherein the first layer is molybdenum oxynitride and molybdenum nitride.

13. A method according to claim 1, wherein the first ALD treatment is performed at a temperature lower than 400°C.

14. A method according to claim 13, wherein the second ALD treatment is performed at a temperature higher than 400°C.

15. A method according to claim 1, wherein the deposition of the first layer and the deposition of the elemental layer are performed in the same chamber.

16. A method according to claim 15, wherein the deposition of the first layer and the deposition of the elemental layer are performed in different stations of the same chamber.

17. A method according to claim 1, wherein the deposition of the first layer is carried out in a first chamber and the deposition of the elemental layer is carried out in a second chamber.

18. A method according to claim 1, further comprising the step of exposing the first layer to air before the deposition of the elemental layer.

19. It is a device, First and second processing chambers, each configured to accommodate a substrate, A substrate support in each of the processing chambers, A gas inlet configured to direct the gas into each of the aforementioned processing chambers, A heater configured to heat the substrate support in each processing chamber, It is a controller, (a) A program instruction to sequentially introduce a metal acid chloride precursor and ammonia into the first processing chamber while the substrate is housed in the first processing chamber. (b) After (a), a program instruction for transferring the substrate to the second processing chamber, and A controller comprising program instructions for sequentially introducing a metal chloride precursor and hydrogen into the second processing chamber while the substrate is housed in the second processing chamber, following (c) and (b), A device equipped with the following features.

20. It is a device, A processing chamber having one or more stations, each configured to accommodate a substrate, A substrate support in each of the one or more stations, A gas inlet configured to direct the gas into each of the one or more stations, A heater configured to heat the substrate support within each station, It is a controller, A program instruction for sequentially introducing a metal chloride precursor and ammonia into one of the one or more stations, A controller comprising program instructions for sequentially introducing a metal chloride precursor and hydrogen into one of the one or more stations, A device equipped with the following features.

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