Substantially carbon-free molybdenum - and tungsten-containing films in the manufacture of semiconductor devices

Abstract

To provide a method for forming a metal-containing layer containing substantially no carbon on a semiconductor substrate.SOLUTION: Substantially carbon-free molybdenum (Mo) - and tungsten-containing films are deposited on a semiconductor substrate using halide-free metalorganic precursors. The precursors are free of metal-carbon bonds and carbonyl ligands, and preferably free of β - hydrogen atoms. Metal-containing films such as Mo nitrides, Mo oxynitrides, Mo silicides, and Mo borides are deposited having a carbon content of less than about 5 atomic%. In one embodiment, the film is deposited by reacting a metal-containing precursor and a reactant on a substrate surface in the absence of a plasma, for example, using multiple ALD cycles. In one embodiment, the formed film is then treated with a second reactant in a plasma to modify its properties. The films can be used as liner layers, diffusion barrier layers, and electrode materials in pMOS devices.SELECTED DRAWING: Figure 1B

Description

[Technical Field]

[0001] [Incorporated by reference] A PCT application form is being filed concurrently herewith as part of this application. Each application to which this application claims benefit or priority, identified in the concurrently filed PCT application form, is hereby incorporated by reference in its entirety for all purposes.

[0002] The present invention relates to methods for fabricating semiconductor devices. In particular, embodiments of the present invention relate to the deposition of molybdenum- and tungsten-containing films in semiconductor processing. [Background technology]

[0003] In integrated circuit (IC) manufacturing, deposition and etching techniques are used to pattern materials, such as forming metal interconnects embedded in dielectric layers. Some patterning methods require conformal deposition of materials, where the deposited layer must follow the contours of protruding and / or recessed features on the substrate surface. Atomic layer deposition (ALD) is often the preferred method for forming conformal films on substrates because it relies on the adsorption of one or more reactants (precursors) on the substrate surface and the subsequent chemical conversion of the adsorbed layer into the desired material. ALD can achieve thin conformal layers with excellent step coverage by using sequential reactions on the substrate surface that are separated in time and typically limited by the amount of adsorbed reactants.

[0004] Chemical vapor deposition (CVD) is another deposition method widely used in semiconductor processing. In CVD, the reaction occurs within the volume of the processing chamber and is not limited by the amount of reactants adsorbed on the substrate. As a result, films deposited by CVD are often less conformal than films deposited by ALD. Typically, CVD is used in applications where step coverage is less critical.

[0005] ALD and CVD often use plasma to drive the reaction of deposition precursors to form the desired film. Methods that utilize plasma are known as plasma-enhanced ALD (PEALD) and plasma-enhanced CVD (PECVD). Methods that do not use plasma are called thermal ALD and thermal CVD.

[0006] Although ALD and CVD are most commonly used for the deposition of silicon-containing films such as silicon oxide, silicon nitride, and silicon carbide, these methods are also suitable for the deposition of some metals, particularly tungsten and cobalt.

[0007] The background art provided herein is intended to provide a general background to the present disclosure. To the extent that it is described in this background art section, the work of the currently named inventors and aspects of the description that may not otherwise be considered prior art at the time of filing are not admitted, explicitly or implicitly, to be prior art to the present disclosure. Summary of the Invention

[0008] Methods are provided for depositing substantially carbon-free molybdenum- and tungsten-containing films, such as metallic molybdenum, molybdenum nitride (MoN), molybdenum boride (MoB), molybdenum silicide (MoSi), and combinations thereof (e.g., MoON). Semiconductor device structures including such films (e.g., as liner layers, diffusion barrier layers, or electrode layers) are also provided.

[0009] In one embodiment, a method for forming a substantially carbon-free metal-containing layer on a semiconductor substrate is provided. The method includes introducing a metal-containing precursor into a process chamber containing the semiconductor substrate. The precursor is a halide- and carbonyl-free compound having at least one ligand bonded to a metal selected from the group consisting of molybdenum and tungsten, wherein the halide- and carbonyl-free compound does not contain a metal-carbon bond or a metal-oxygen double bond. The method further includes reacting the metal-containing precursor with at least one reactant in the absence of a plasma to form a metal-containing layer on the semiconductor substrate. The formed metal-containing layer is a substantially carbon-free molybdenum- or tungsten-containing layer having a carbon content of less than about 5 atomic % (e.g., less than about 2 atomic %), the layer being selected from the group consisting of Mo, W, MoN, WN, MoON, WON, MoB, WB, MoSi, WSi, and combinations thereof. The combination may include, for example, a MoNB layer or a WONSi layer. In some embodiments, the molybdenum-containing precursor or the tungsten-containing precursor does not contain β-hydrogen atoms. In some embodiments, the formed layer is post-treated (e.g., by plasma treatment) to modify the electrical properties of the layer. In some embodiments, the formed layer is an electrode layer in a pMOS (p-type metal oxide semiconductor) device.

[0010] In another aspect, a semiconductor device is provided, the semiconductor device comprising a substantially carbon-free metal-containing liner layer, the metal being selected from the group consisting of molybdenum and tungsten, the carbon content in the substantially carbon-free metal-containing layer being less than about 3 atomic %, and the substantially carbon-free metal liner layer having a thickness less than about 50 Å and a surface area of ​​about 3,000 μcm. -1 and the liner layer has a resistivity less than 100 .mu.m and is disposed between the dielectric layer and the conductive layer. In some embodiments, the substantially carbon-free liner layer is a diffusion barrier layer.

[0011] In another aspect, a semiconductor device is provided that includes a gate electrode. The gate electrode includes a substantially carbon-free metal-containing layer, the substantially carbon-free metal-containing layer having a carbon content of less than about 3 atomic %, the substantially carbon-free metal-containing layer having a work function greater than 4.9 eV, and comprising a metal selected from the group consisting of molybdenum and tungsten. In some embodiments, the substantially carbon-free metal-containing layer is a MoN layer.

[0012] In another aspect, an apparatus for forming a substantially carbon-free metal-containing layer on a semiconductor substrate is provided, the apparatus comprising: (a) a deposition processing chamber having a substrate support pedestal, an inlet for introducing a metal-containing precursor, and a second inlet for introducing at least one reactant; (b) a plasma processing chamber separate from the deposition processing chamber, the plasma processing chamber having a substrate support pedestal and an inlet for introducing a plasma treatment reactant; and (c) a controller including program instructions for (i) generating a surface-limited reaction of a metal-containing precursor with at least one reactant in the deposition processing chamber in the absence of a plasma to form a layer of a substantially carbon-free metal-containing material, the metal being selected from the group consisting of molybdenum and tungsten, (ii) transferring the semiconductor substrate from the deposition processing chamber to the plasma processing chamber without exposure to ambient atmosphere, and (iii) treating the substantially carbon-free metal-containing material with a plasma-activated plasma treatment reactant.

[0013] In another aspect, a flow mixer for mixing a carrier gas and a metal-containing precursor is provided, the flow mixer including: (a) an outer fluid conduit, the outer fluid conduit having an inlet for flowing the carrier gas into the outer fluid conduit, a mixing zone for mixing the carrier gas with the metal-containing precursor, and an outlet for discharging the carrier gas mixed with the metal-containing precursor from the outer fluid conduit; and (b) an inner fluid conduit disposed at least partially within the outer fluid conduit, the inner fluid conduit having an inlet for flowing the metal-containing precursor into the inner fluid conduit and an outlet configured to release the metal-containing precursor into the outer fluid conduit, wherein a distance from the inlet of the inner fluid conduit to the inlet of the outer fluid conduit is greater than a distance from the outlet of the inner fluid conduit to the inlet of the outer fluid conduit, thereby enabling counter-flow of the carrier gas and the metal-containing precursor through the flow mixer, the distance being in the z-direction.

[0014] In another aspect, a method of depositing a metal-containing layer on a semiconductor substrate is provided, the method including: (a) mixing a metal-containing precursor with a carrier gas in a flow mixer described herein; and (b) delivering the resulting mixture to a process chamber where the metal-containing precursor reacts with a reactant to form the metal-containing layer on the semiconductor substrate.

[0015] In another aspect, a multi-plenum showerhead for delivering multiple reactants to a processing chamber is provided, the multi-plenum showerhead including: (a) a showerhead faceplate including a first plurality of conduits for delivering a first reactant and a second plurality of conduits for delivering a second reactant, the first plurality of conduits being fluidly isolated from the second plurality of conduits; and (b) a showerhead housing disposed around an outer periphery of the showerhead faceplate, the showerhead housing to which the showerhead faceplate is removably attached.

[0016] In another embodiment, a faceplate of a showerhead for a deposition apparatus is provided, the faceplate including a first plurality of conduits for supplying a first reactant and a second plurality of conduits for supplying a second reactant, the first plurality of conduits configured to be fluidly isolated from the second plurality of conduits, and the faceplate configured to be removably attached to a showerhead housing.

[0017] In another embodiment, a deposition apparatus for depositing a metal-containing layer over a semiconductor substrate is provided, the deposition apparatus including a multi-plenum showerhead as described herein.

[0018] These and other aspects of implementations of the subject matter described herein are illustrated in the accompanying drawings and the description that follows. [Brief explanation of the drawings]

[0019] [Figure 1A] FIG. 1A illustrates an example of a molybdenum precursor that can be used in deposition methods according to embodiments described herein.

[0020] [Figure 1B] FIG. 1B illustrates some specific examples of molybdenum precursors that can be used in methods according to embodiments described herein.

[0021] [Figure 2] FIG. 2 is a process flow diagram of a method for forming a metal-containing film according to embodiments described herein.

[0022] [Figure 3] FIG. 3 is a process flow diagram of a method for forming a metal-containing film according to embodiments described herein.

[0023] [Figure 4A] FIG. 4A is a process flow diagram of a method for treating a metal-containing film according to embodiments described herein.

[0024] [Figure 4B] FIG. 4B is a process flow diagram of a method for treating a metal-containing film according to embodiments described herein.

[0025] [Figure 5] FIG. 5 is a schematic cross-sectional view of a pMOS device structure including a layer of substantially carbon-free metal-containing material according to embodiments described herein.

[0026] [Figure 6A] FIG. 6A is a schematic cross-sectional view of a semiconductor device during fabrication according to embodiments described herein. [Figure 6B] FIG. 6B is a schematic cross-sectional view of a semiconductor device during fabrication according to embodiments described herein. [Figure 6C] FIG. 6C is a schematic cross-sectional view of a semiconductor device during fabrication according to embodiments described herein.

[0027] [Figure 7] FIG. 7 is a schematic diagram of an apparatus suitable for depositing molybdenum-containing films according to embodiments described herein.

[0028] [Figure 8] FIG. 8 is a schematic diagram of a multi-station processing system according to embodiments described herein.

[0029] [Figure 9] FIG. 9 is a schematic diagram of a multi-station processing system according to embodiments described herein.

[0030] [Figure 10] FIG. 10 is a schematic side view, with partial cross section, of a flow mixer according to embodiments described herein.

[0031] [Figure 11A]FIG. 11A illustrates a portion of a dual plenum showerhead assembly according to embodiments described herein.

[0032] [Figure 11B] FIG. 11B illustrates a portion of a showerhead faceplate removed from a showerhead housing according to embodiments described herein. DETAILED DESCRIPTION OF THE INVENTION

[0033] Methods are provided for depositing substantially carbon-free molybdenum- and tungsten-containing films on semiconductor substrates. These methods can be used, for example, to deposit a blanket, substantially carbon-free metal-containing layer on a planar substrate, to deposit a conformal metal-containing layer on a substrate having one or more recessed or raised features, and to fill recessed features with a substantially carbon-free metal-containing material. In some embodiments, methods are provided for forming a substantially carbon-free metal-containing layer on a semiconductor substrate as a liner layer or diffusion barrier layer. In some embodiments, methods are provided for forming a substantially carbon-free metal-containing layer as an electrode layer in a pMOS device.

[0034] These methods can be used to deposit a variety of molybdenum- and tungsten-containing materials, including, but not limited to, molybdenum metal (Mo), molybdenum nitride (MoN), molybdenum boride (MoB), molybdenum silicide (MoSi), and molybdenum oxynitride (MoON), as well as tungsten metal (W), tungsten nitride (WN), tungsten boride (WB), tungsten silicide (WSi), and tungsten oxynitride (WON). Note that the stoichiometry of these compounds may vary, and the formulas provided do not imply stoichiometry. For example, in various embodiments, MoN can contain approximately 10-70 atomic % nitrogen.

[0035] The term "substantially carbon-free" refers to a material having a carbon content of less than about 5 atomic %, where hydrogen, if present, is excluded from the calculation. In some embodiments, substantially carbon-free films are provided that contain less than about 3 atomic % carbon (such as less than about 2 atomic % carbon).

[0036] As used herein, the term "metal" (e.g., "metallic molybdenum" or "metallic tungsten") refers to a material that consists essentially of a metal (e.g., Mo or W). Other elements (e.g., B, Si, N, or O) may be present in the metal in small amounts (e.g., a total content of less than about 15 atomic %, or less than about 10%, where hydrogen is not included in the calculation).

[0037] Molybdenum nitride (MoN), molybdenum boride (MoB), molybdenum silicide (MoSi), molybdenum oxynitride (MoON), tungsten nitride (WN), tungsten boride (WB), tungsten silicide (WSi), and tungsten oxynitride (WON) refer to materials consisting essentially of the listed elements. The stoichiometry of these compounds may vary and is not determined by the listed formula (e.g., MoN does not necessarily indicate a 1:1 Mo:N stoichiometry). Other elements may be present in these compounds in small amounts (e.g., less than about 10 atomic percent, where hydrogen is excluded from the calculation).

[0038] As used herein, the term "semiconductor substrate" refers to a substrate at any stage in the fabrication of a semiconductor device that includes semiconductor material anywhere within its structure. It is understood that the semiconductor material in a semiconductor substrate need not be exposed. An example of a semiconductor substrate includes a semiconductor wafer having multiple layers of other materials (e.g., dielectrics) covering the semiconductor material. The following detailed description assumes that implementations of the present disclosure are implemented in a semiconductor wafer (such as a 200 mm, 300 mm, or 450 mm semiconductor wafer). However, implementations of the present disclosure are not limited thereto. Workpieces may be constructed of various shapes, sizes, and materials. In addition to semiconductor wafers, workpieces that can utilize implementations of the present disclosure include various articles, such as printed circuit boards.

[0039] When the term "about" is used in reference to a numerical value, it includes a range of ±10% of the stated numerical value, unless otherwise specified.

[0040] As used herein, the term "alkyl" means a saturated substituent containing only carbon and hydrogen atoms. Alkyl includes straight-chain, branched, and cyclic groups. Examples of straight-chain alkyl groups include, but are not limited to, methyl, ethyl, n-propyl, n-butyl, and the like. Examples of branched alkyl groups include, but are not limited to, isopropyl, isobutyl, sec-butyl, t-butyl, and the like. Examples of cycloalkyl include, but are not limited to, cyclopropyl, cyclopentyl, cyclohexyl, and the like.

[0041] As used herein, the term "fluoroalkyl" refers to an alkyl group that includes one or more fluorine substituents. In some implementations, the fluoroalkyl includes only fluorine substituents, such as CF, C2F5, C3F7, etc. The fluoroalkyl may be linear, branched, or cyclic.

[0042] As used herein, the term "alkylsilyl" refers to the SiR group, where at least one R is alkyl and each R is independently selected from H and alkyl. Alkylsilyl includes monoalkylsilyl, bisalkylsilyl, and trisalkylsilyl. Examples of alkylsilyl include trimethylsilyl, dimethylsilyl, methylsilyl, triethylsilyl, diethylsilyl, and ethylsilyl.

[0043] As used herein, the term "alkylamino" refers to the group NR2, where at least one R is alkyl and each R is independently selected from H and alkyl. Examples of alkylamino substituents include dimethylamino and diethylamino substituents.

[0044] The term "alkoxy" refers to the group OR, where R is alkyl. Examples of alkoxy groups include methoxy, ethoxy, and propoxy groups.

[0045] With respect to the selection of R substituents in a molecule having multiple R groups, the term "independently selected" means that the selection of R substituents at different atoms of the molecule is independent, and that the selection of R substituents at an atom having multiple R substituents is also independent.

[0046] As used herein, the term "metal organic precursor" refers to a metal-containing compound that contains at least one carbon-containing ligand. These compounds do not contain a metal-carbon bond.

[0047] Although the embodiments of the present invention will be described primarily with reference to molybdenum-containing precursors and molybdenum-containing films, it will be understood that the general descriptions and principles herein also apply to tungsten-containing precursors and tungsten-containing films.

[0048] Depositing molybdenum- and tungsten-containing films with desired properties onto semiconductor substrates presents several challenges that have prevented their incorporation into many device manufacturing process flows. Specifically, halide-containing molybdenum and tungsten precursors used as CVD and ALD precursors can unintentionally etch the substrate. While metalorganic and organometallic precursors overcome the integration challenges associated with halide-containing precursors, carbon-containing precursors tend to incorporate significant amounts of carbon into the resulting films because molybdenum and tungsten form highly stable carbide phases. Carbon-containing films are undesirable for many applications because their presence can increase the resistivity and lower the work function of the film.

[0049] Methods for depositing substantially carbon-free molybdenum- and tungsten-containing films are provided. These methods are useful for depositing molybdenum- and tungsten-containing materials, such as nitrides, borides, silicides, oxynitrides, and combinations thereof. Some of the materials deposited by these methods are used as gate electrode materials for MOSFETs (metal-oxide-semiconductor field-effect transistors). Because carbon negatively impacts the effective work function of early transition metal films, these methods are advantageous for producing films with high work functions (e.g., greater than about 5 eV) suitable for pMOS structures. Some of the materials deposited by these methods are also useful as ultrathin, low-resistivity liner and / or barrier materials. In some embodiments, these methods are carried out in an integrated multi-chamber apparatus, for example, having a deposition chamber and a plasma treatment chamber. In this apparatus, a substantially carbon-free film is deposited by CVD or ALD in the deposition chamber without plasma and then plasma-treated in the plasma treatment chamber. Plasma treatment can be used to adjust the film composition, densify the formed film, and / or adjust the effective work function of the formed material.

[0050] The methods provided herein utilize halide-free, molybdenum- or tungsten-containing metal organic compounds as CVD or ALD precursors, where the metal organic compounds do not contain metal-carbon (molybdenum-carbon or tungsten-carbon) bonds and do not contain carbonyl (CO) ligands. Furthermore, in some embodiments, the precursors do not contain β-hydrogen atoms. Deposition is carried out by reacting the precursor with a reactant, preferably in the absence of a plasma. In some embodiments, the reaction is carried out in the absence of a plasma at a temperature below about 450°C (e.g., below about 420°C). Careful precursor selection advantageously avoids significant carbon incorporation into the resulting film, allowing for the formation of films with a carbon content of less than about 5 atomic % (e.g., less than about 3 atomic %).

[0051] This result was unexpected because metal-organic precursors contain carbon, and molybdenum and tungsten have a high affinity for carbon, which would inevitably lead to high levels of carbon incorporation into the films. However, we discovered that carbon incorporation can be avoided when the metal in the precursor does not form direct bonds with carbon and the precursor does not contain carbonyl ligands, especially when plasma is not used during the deposition reaction. Another factor that significantly reduces carbon incorporation into the films is the absence of β-hydrogen in the ligands of the metal-containing precursors. β-hydrogen is thought to lead to low-energy reaction pathways, thereby allowing carbon incorporation into the films even at low-temperature deposition conditions. Furthermore, the absence of β-hydrogen stabilizes the ligands without decomposition, potentially allowing them to be removed intact during subsequent exposure to reactant gases.

[0052] In some embodiments, a metal-containing precursor as used herein includes a metal (e.g., molybdenum or tungsten) that forms bonds only with elements selected from the group consisting of N, O, and S. In some embodiments, it is preferred that the precursor does not include a β-hydrogen atom. For example, in some embodiments, the precursor includes a carbon bonded to three alkyl groups at the β-position. In some embodiments, the precursor does not include a metal-oxygen double bond (M=O).

[0053] In some embodiments, precursors that can be used for deposition include halide-free molybdenum and tungsten complexes having at least one monodentate ligand such as an amine, nitrile, imide, nitride, alkoxide, or thiolate, or halide-free molybdenum and tungsten complexes having multidentate ligands that bond to the metal through an N, O, or S atom. Preferably, the ligand does not contain a β-hydrogen atom.

[0054] Figure 1 shows examples of suitable molybdenum-containing precursors 1-16. Here, each L is a carbon-containing ligand that does not form a metal-carbon bond, m is an integer from 1 to 4, and n is an integer from 1 to 4. Each of R and R1 is independently selected from the group consisting of alkyl, fluoroalkyl, and alkylsilyl. In some embodiments, each R1 is selected so as not to provide a β-hydrogen atom. Examples of such R1 substituents include t-butyl and trialkylsilyl substituents. In some embodiments, R substituents at O ​​and S atoms may provide a β-hydrogen atom. This is because β-hydrogens at these positions are not readily removed and are believed not to result in carbon contamination of the resulting film. Furthermore, in compounds 7, 8, and 14, the β-hydrogen at the alkyl-substituted carbon atom adjacent to the anionic nitrogen is also stabilized. These stabilized compounds are also suitable for depositing the films provided herein.

[0055] In some embodiments, neither R nor R contributes a β-hydrogen atom. In some embodiments, the precursor does not contain a β-hydrogen atom. For example, in some embodiments, the precursor is any of compounds 1, 2, 3, 4, 5, 6, 15, and 16, and each of R, R, and L does not contribute a β-hydrogen atom.

[0056] Figure 1B shows structures 17-20 as more specific examples of molybdenum-containing precursors. It can be seen that molybdenum bonds only with N and O atoms, and the precursors contain no hydrogen atoms at the β-position. The precursors can be synthesized by reacting a molybdenum starting material, such as a halide-containing molybdenum starting material, with a deprotonating ligand. Examples of synthetic routes are described in U.S. Patent Application Publication No. 2018 / 0355484.

[0057] The precursors used for deposition are easily vaporized and stable at the target temperature and pressure. For example, in some embodiments, precursors are used in deposition reactions at temperatures below about 450° C. (e.g., below about 420° C.). In many embodiments described herein, precursors are selected that have a molecular weight below about 450 g / mol (e.g., below about 400 g / mol) to maintain adequate volatility.

[0058] Substantially carbon-free molybdenum- and tungsten-containing materials can be deposited by various deposition methods, such as CVD and ALD, using the precursors described herein. An example of a method for depositing a molybdenum- or tungsten-containing layer is shown in the process flow diagram of FIG. 2. The process begins in step 201 by introducing a halide-free molybdenum- or tungsten-containing precursor into a process chamber containing a semiconductor substrate. The precursor has no metal-carbon bonds and preferably no beta-hydrogen atoms. The precursor can be introduced in a vaporized state in a flow of an inert gas, such as argon, helium, or nitrogen (N). In step 203 (which can be performed before, after, or during the introduction of the molybdenum-containing precursor 201), reactants are introduced into the process chamber containing the substrate. In some embodiments, the introduction of the metal-containing precursor and the introduction of the reactants are performed sequentially. The chemical nature of the reactants depends on the chemical nature of the molybdenum- or tungsten-containing film of interest. For example, when depositing a metal (Mo or W), the second reactant is typically a reducing reactant (e.g., H). Metal nitride deposition can be performed using a nitrogen-containing reactant (e.g., NH or N2H4). In some embodiments, metal nitrides are deposited using H2 as a reactant. The necessary nitrogen can be provided by a ligand. Metal borides can be deposited using a boron-containing reactant (e.g., B2H6). Metal silicides can be formed using a silicon-containing reactant (e.g., SiH4 or Si2H6).

[0059] In some embodiments, the precursor and reactant are mixed within the body of the processing chamber. In other embodiments, after the metal-containing precursor is introduced and adsorbed on the substrate surface, the processing chamber is purged with an inert gas and / or evacuated to remove unadsorbed precursor from the processing chamber. In some embodiments, the precursor layer on the substrate is adsorption-limited. In other embodiments, a thicker precursor layer can be formed on the substrate surface before purging and / or evacuating the processing chamber. Note that when the precursor and reactant are introduced sequentially, the order of precursor and reactant introduction can be reversed. In some embodiments, the reactant is introduced first and allowed to adsorb on the substrate surface. The processing chamber is then purged and / or evacuated to remove the second reactant from the processing chamber volume, after which the precursor is introduced.

[0060] Referring to step 205, the precursor is reacted with a reactant to form a layer of substantially carbon-free molybdenum-containing material on the substrate. The reaction occurs on the substrate surface and / or within the body of the processing chamber, preferably in the absence of plasma. For example, in a CVD process, the precursor and reactant may be simultaneously introduced into the body of the processing chamber. The reaction occurs sequentially either within the body of the processing chamber or on the substrate surface. In an ALD process, the reaction occurs only on the substrate surface and is limited by the amount of adsorbed material (amount of precursor and / or amount of adsorbed reactant) on the surface. The temperature during the reaction process can be, for example, about 20-600°C. In some embodiments, low-temperature deposition is performed at about 450°C or below (e.g., about 420°C or below, e.g., about 200-400°C). This is particularly advantageous for depositing substantially carbon-free films. The pressure in the processing chamber can be in the range of about 0.1 to 100 Torr (about 13.3322 to 13332.2 Pa) in thermal ALD, for example, about 1 to 60 Torr (about 13.3322 to 7999.34 Pa) (such as about 10 Torr (about 1333.22 Pa)).

[0061] After the reaction is complete, the formed molybdenum- or tungsten-containing layer may optionally be treated with a second reactant to modify the layer, as shown in step 207. This treatment may be performed to adjust the layer's properties, such as densifying the layer, modifying the layer's composition or electrical properties, or reducing the layer's resistivity. In some embodiments, this treatment is performed using a plasma. For example, the substrate may be treated with a direct plasma (formed within the compartment containing the substrate) or a remote plasma (formed remotely from the substrate and introduced into the compartment containing the substrate). In some cases, using a remote plasma is preferred because it reduces damage to the substrate. In a preferred embodiment, a substantially carbon-free molybdenum- or tungsten-containing layer is deposited in the absence of a plasma. The substrate is then transferred to a plasma processing chamber without exposure to ambient atmosphere and treated with a plasma processing reactant in the plasma processing chamber. The choice of plasma processing reactant depends on the desired properties of the final layer. The substrate may be treated with, for example, plasma activated H2, NH3, N2, BH3, SiH4, Ar, He, and mixtures thereof.

[0062] An example of a surface deposition process for forming a molybdenum- or tungsten-containing film on a substrate is illustrated by the process flow chart shown in FIG. 3. In step 301, a layer of metal-containing precursor and / or reactant is formed on the surface of the substrate. In some embodiments, this layer is an adsorption-limiting layer. Next, in step 303, the process chamber is purged and / or evacuated. This step ensures that the precursor and / or reactant are present only on the surface of the substrate and not within the volume of the process chamber. Next, in step 305, the precursor is reacted with a reactant on the surface of the substrate. For example, if only the metal-containing precursor is adsorbed on the surface of the substrate in step 301, the reactant may be introduced into the process chamber and react with the precursor on the surface. If both the metal-containing precursor layer and the reactant layer are formed on the surface of the substrate in step 301, the process conditions may be adjusted (e.g., the temperature may be increased) to activate the reaction in step 313. Next, in step 307, the process chamber is purged and / or evacuated, and in step 309, steps 301-307 are repeated to form additional metal-containing material. In some embodiments, each cycle of steps 301-307 deposits an average of about 0.1-5 Å of metal-containing material. In some embodiments, 1-100 (e.g., 2-100) cycles are performed. For example, 1-20 (e.g., 2-20) cycles can be performed. Substantially carbon-free molybdenum-containing and tungsten-containing layers having thicknesses of about 5-500 Å (e.g., 5-50 Å) can be formed with a high level of layer thickness control. Using this method, conformal layers with excellent step coverage can be formed.

[0063] In some embodiments, the deposited substantially carbon-free molybdenum- and tungsten-containing films are treated with a second reactant to modify film properties such as density, resistivity, or effective work function.

[0064] FIG. 4A is a process flow diagram for one example of film modification. The process begins in step 401 by reacting a molybdenum-containing precursor with a reactant to form a substantially carbon-free molybdenum-containing film on a substrate in the absence of plasma. For example, multiple cycles of reacting a halide-free metalorganic molybdenum-containing precursor with NH or H in the absence of plasma can be performed to form a MoN layer on the surface of the substrate. Next, in step 403, the film is treated with a plasma-activated nitrogen-containing reactant to increase the nitrogen content in the film. For example, a MoN film can be treated with a plasma formed in a process gas containing N to increase the nitrogen content in the MoN layer. In some embodiments, the nitrogen content increases by at least 5% (e.g., at least 10%) upon such treatment. The increased nitrogen content in the MoN layer is accompanied by an increase in work function. In some embodiments, the increase in work function upon this treatment is at least 30 meV (e.g., 50-200 meV). In some embodiments, the resulting MoN material after this treatment has a nitrogen content of at least 25 atomic % and a work function of at least about 5.0 eV (such as at least 5.2 eV).

[0065] Another example of post-treatment is described using the process flow chart shown in FIG. 4B. Similar to FIG. 4A, in this example, the process begins in step 411 by reacting a molybdenum-containing precursor with a reactant to form a substantially carbon-free molybdenum-containing layer. Next, in step 413, the formed layer is treated with a plasma-activated hydrogen-containing reactant to reduce the layer's resistivity. For example, a substantially carbon-free molybdenum nitride layer may be treated with a plasma formed in a process gas containing H, thereby significantly reducing the film's resistivity. In some embodiments, the resistivity can be reduced by at least 20% (such as at least 50%, or even at least 80%) by this treatment. In some embodiments, the H plasma treatment reduces the film's resistivity by at least two, three, or five times. In some embodiments, the H plasma treatment results in a film having a resistivity of less than about 1,000 μΩ·cm (such as less than about 800 μΩ·cm). In some embodiments, a plasma treatment (e.g., a plasma treatment using a hydrogen-containing reactant such as H) is further used to densify the deposited film. For example, H2 plasma post-treatment can increase the density of the film by at least 20%, such as at least 40%.

[0066] The substantially carbon-free molybdenum- and tungsten-containing films provided herein can be deposited on a variety of surfaces, including metals (e.g., copper, nickel, cobalt, tungsten, etc.), dielectrics (e.g., silicon oxide-based dielectrics, silicon nitrides, silicon carbides, metal oxides, metal nitrides, etc.), and amorphous and crystalline silicon. In some embodiments, the films are deposited as liner layers or diffusion barrier layers.

[0067] In one implementation, the substantially carbon-free metal-containing films provided herein are used as MOSFET gate electrode materials. As an example, the films provided herein are incorporated into a pMOS device structure. Figure 5 shows a schematic cross-sectional view of a pMOS device. The device (e.g., a transistor) includes a semiconductor layer 501, a source region 501, a drain region 503, and a gate dielectric layer 505 formed on the semiconductor layer 501 to define a channel region 515 in the semiconductor layer 501 between the source region 501 and the drain region 503. The semiconductor layer 501 includes a semiconductor material such as silicon (Si), germanium (Ge), or silicon germanium (SiGe). In one embodiment, the gate dielectric layer 505 includes a high-k dielectric having a dielectric constant greater than about 3.9. For example, the gate dielectric layer 505 may include a high-k material such as HfO, HfSiO, or HfSiON. The gate dielectric layer is typically very thin, e.g., having a thickness of about 10-15 Å. Layers 509, 511, and 513 are disposed on gate dielectric layer 505 and collectively form a gate electrode. Layer 509 is an optional cap layer formed directly on and in contact with gate dielectric layer 505. In some embodiments, cap layer 509 comprises TiN, TaN, and / or WN and has a thickness of approximately 10-20 Å. Layer 511 above cap layer 509 is referred to as a high work function metal-containing layer. Layer 511 comprises a substantially carbon-free molybdenum- or tungsten-containing material as provided herein. These materials have a high work function, such as a work function greater than about 4.9 eV, greater than about 5.0 eV, or greater than about 5.1 eV. In some embodiments, layer 511 is a substantially carbon-free MoN layer having an effective work function greater than about 5.0. The substantially carbon-free layer is deposited by the ALD or CVD methods described herein and, in some embodiments, is further treated with a plasma treatment reactant to increase its work function. For example, in some embodiments, the deposited substantially carbon-free molybdenum- or tungsten-containing material is treated with a plasma-activated nitrogen-containing reactant (e.g., N) to increase the nitrogen content and work function of the formed layer.In some embodiments, layer 511 has a thickness of about 5-50 Å, or 5-15 Å. In one implementation, work function metal-containing layer 511 has a thickness of about 30 Å. In some embodiments, substantially carbon-free metal-containing layer 511 is deposited directly on cap layer 509. In the absence of cap layer 509, layer 511 may be deposited directly on gate dielectric layer 507. Finally, the device may optionally include one or more conductive layers 513 formed on substantially carbon-free metal-containing layer 511. In some embodiments, conductive layer 513 includes one or more of TiAl, TiAlC, TiAlON, and / or a conductive metal filler such as Mo, Co, or W. The device shown in FIG. 5 is a schematic representation of a partially fabricated device, and contacts formed on the source and drain regions are not shown. The contacts can be formed after the formation of the electrode layers.

[0068] The substantially carbon-free molybdenum- and tungsten-containing layers provided herein may be used in planar pMOS devices, FinFET pMOS devices, or gate-all-around (GAA) pMOS devices, and films having a work function greater than 5.0 eV (e.g., about 5.0 to 5.5 eV) can be obtained.

[0069] In another application, a substantially carbon-free film is deposited as a diffusion barrier layer on a substrate having recessed features, such as vias or trenches. Schematic cross-sectional views of an exemplary substrate during fabrication are shown in FIGS. 6A-6B. Referring to FIG. 6A, a substrate is provided that includes a dielectric layer 601 having a recessed feature 603 formed therein. The dielectric may be a silicon oxide-based interlevel dielectric (e.g., a low-k dielectric). Referring to FIG. 6B, a substantially carbon-free molybdenum- or tungsten-containing film 605 is conformally deposited on the dielectric 601, covering the recessed feature. The conformal film is preferably deposited by ALD using precursors described herein. In some embodiments, the film 605 is deposited directly on the dielectric. In other embodiments, one or more additional layers, such as an adhesion layer, may be formed on the dielectric prior to deposition of the film 605. Next, referring to FIG. 6B, the recessed feature 603 is filled with a metal, such as copper or cobalt. Copper or cobalt may be deposited, for example, by electrodeposition onto a thin conformal metal seed layer (not shown). The structure thus formed includes a thin, substantially carbon-free molybdenum- or tungsten-containing layer between the dielectric layer and the metal-filled via or trench. In some embodiments, film 605 has a thickness of about 5-50 Å (e.g., about 10-30 Å). In some embodiments, film 605 is a diffusion barrier layer that prevents copper diffusion into the dielectric. Examples of suitable diffusion barrier materials include MoN and WN. In some embodiments, film 605 is an adhesion layer that can promote adhesion between conventional diffusion barrier layers (e.g., TaN or TiN) and the conductive seed layer. Examples of suitable adhesion layer materials include Mo and MoN with a relatively low nitrogen content. In many embodiments, film 605 is preferably a low-resistivity film, such as a film having a resistivity of less than about 1000 μΩ·cm (e.g., less than about 500 μΩ·cm). In some embodiments, these films are formed by plasma post-treating the deposited substantially carbon-free film, which post-treatment reduces the resistivity of the deposited film.For example, in some embodiments, the deposited film (e.g., a MoN or WN film) is post-treated with a plasma formed in a hydrogen-containing gas (e.g., H2), as described with reference to Figure 4B.

[0070] Although the description herein exemplifies the deposition of molybdenum, tungsten-containing layers can also be deposited using similar precursors and conditions. For example, a tungsten-containing precursor having the same structure as shown in Figures 1A and 1B (with tungsten instead of molybdenum) can be used.

[0071] [Experimental Example] Example 1: Substantially carbon-free MoN films were deposited on SiO2 substrates using bis(tert-butylimido)bis(tert-butoxy)molybdenum (compound 19), shown in Figure 1B, as the molybdenum-containing precursor. The substrate was exposed to precursor 19 in an ALD processing chamber, the processing chamber was then purged to remove any unsurface-bound precursor, and the substrate was then contacted with reactants (NH3, H2, or a combination of NH3 and H2, delivered as a mixture or delivered sequentially) to react with the precursor on the substrate surface. The processing chamber was purged, and the precursor and reactant administrations were repeated. 1 to 500 ALD cycles were used. Deposition was performed in the absence of plasma at temperatures between 300 and 400 °C.

[0072] The composition of the deposited MoN films was analyzed by both X-ray photoelectron spectroscopy (XPS) and secondary ion mass spectrometry (SIMS), and the carbon content was found to be 0.2–2 atomic %. The film resistivity was 500–4,000 μΩ·cm for thicknesses of 2–10 nm.

[0073] A 2-nm-thick film was subjected to H plasma treatment for 60 seconds. The film was treated at 400 °C using a remotely generated plasma (13.56 MHz, 2 kW) in a H-containing process gas. The resulting 1-nm film (measured by TEM) had a resistivity of approximately 600 μΩ·cm, a six-fold decrease compared to the initial resistivity of 3600 μΩ·cm in the as-deposited film.

[0074] Example 2 (Comparative Example): Treatment of a molybdenum precursor with reactants in a plasma was shown to result in significant carbon incorporation. MoC films were deposited on SiO2 substrates using bis(tert-butylimido)bis(tert-butoxy)molybdenum (compound 19), shown in Figure 1B, as the molybdenum-containing precursor. The substrate was exposed to precursor 19 in an ALD process chamber, the process chamber was then purged to remove any non-surface-bound precursor, and the substrate was then exposed to a plasma formed in H2 to react with the precursor on the substrate surface. The process chamber was purged, and the precursor and reactant administration was repeated. 200 ALD cycles were used. Deposition was performed at a temperature of 250 °C. The composition of a 15 nm film was analyzed by X-ray photoelectron spectroscopy to be 58 atomic % Mo and 41 atomic % C. It is believed that the high-energy plasma reactants cause unrestricted decomposition of the organic ligands, which facilitates the formation of thermodynamically stable Mo carbide films. Thus, it is difficult to obtain a substantially carbon-free metallic Mo-containing film when using plasma reactants.

[0075] Example 3: A 3 nm substantially carbon-free MoN film was plasma treated with a mixture of N2 and argon at 400°C for 150 seconds. The plasma was remotely generated with a power of 3 kW. MOS capacitors were fabricated, and the effective work function was determined by extrapolating a plot of flat-band voltage versus effective oxide thickness to zero. The plasma-treated film exhibited an increase in effective work function of approximately 0.08 eV relative to the untreated film. Separate experiments performed to characterize compositional changes due to plasma treatment showed that the nitrogen content increased by approximately 10% after plasma treatment.

[0076] [Device] The deposition methods described herein can be performed in a variety of apparatus. A suitable apparatus includes a process chamber having one or more inlets for introducing reactants, a substrate holder within the process chamber configured to hold the substrate in place during deposition, and, optionally, a plasma generating mechanism configured to generate a plasma in the process gas. The apparatus may also include a controller having program instructions for carrying out any of the method steps described herein. The deposition methods described herein may also be performed in corresponding ALD and CVD apparatus manufactured by Lam Research Corp. (Fremont, Calif.), such as Altus®, Vector®, and Striker® tools.

[0077] For example, in some embodiments, the apparatus includes a controller having program instructions including instructions for introducing a molybdenum precursor or a tungsten precursor (any of the precursors described herein) into a process chamber and for reacting the precursor with a reactant to form a layer of substantially carbon-free molybdenum- or tungsten-containing material on the substrate. The controller may include program instructions for performing any of the methods described herein.

[0078] FIG. 7 illustrates an example of a deposition apparatus suitable for depositing molybdenum-containing films using the methods provided herein. FIG. 7 is a schematic diagram of one embodiment of a process station 700 that can be used to deposit materials using atomic layer deposition (ALD) and / or chemical vapor deposition (CVD). Either ALD or CVD may optionally be plasma-activated. Note that in many embodiments, plasma activation of the deposition reaction is avoided to prevent carbon incorporation into the film. For ease of illustration, the process station 700 is shown as a stand-alone process station having a processing chamber body 702 for maintaining a low-pressure environment. However, it is recognized that multiple process stations 700 may be included in a common process tool environment. Furthermore, it is recognized that in some embodiments, one or more hardware parameters in the process station 700, including those described in more detail below, may be programmatically adjusted by one or more computer controllers.

[0079] The process station 700 is in fluid communication with a reactant delivery system 701 for supplying process gases to a distribution showerhead 706. The reactant delivery system 701 includes a mixing vessel 704 for blending and / or conditioning process gases for delivery to the showerhead 706. One or more mixing vessel inlet valves 720 may control the introduction of process gases into the mixing vessel 704. Similarly, a showerhead inlet valve 705 may control the introduction of process gases to the showerhead 706.

[0080] Some metal-containing precursors may be stored in a solid or liquid state before being vaporized and delivered to the process station. For example, the embodiment of FIG. 7 includes a vaporization point 703 for vaporizing a solid reactant delivered to a mixing vessel 704. In some embodiments, the vaporization point 703 may be a heated vaporizer. In some embodiments, a flow of inert gas, at subatmospheric pressure, is passed over a heated solid molybdenum or tungsten precursor or bubbled through a heated liquid molybdenum or tungsten precursor to deliver the precursor vapor to the processing chamber. Precursor vapor from such vaporizers may condense in downstream supply piping. Exposure of incompatible gases to the condensed reactants can generate small particles. These small particles can clog piping, impede valve operation, and contaminate substrates. Addressing these issues involves cleaning and / or evacuating the supply piping to remove residual reactants. However, cleaning the supply piping can increase the cycle time of the process station and reduce process station throughput. Thus, in some embodiments, the supply piping downstream of vaporization point 703 may be heat traced. In some examples, mixing vessel 704 may also be heat traced. As one non-limiting example, the piping downstream of vaporization point 703 has a ramped temperature profile that increases from about 100° C. to about 200° C. at mixing vessel 704.

[0081] The showerhead 706 distributes process gases toward the substrate 712. In the embodiment shown in FIG. 7, the substrate 712 is located below the showerhead 706 and rests on a pedestal 708. It will be appreciated that the showerhead 706 may have any suitable shape and any suitable number of ports in any suitable arrangement for distributing process gases to the substrate 712. Although not explicitly shown, in some embodiments, the showerhead 706 is a dual-plenum showerhead including at least two types of conduits, where a first type of conduit is dedicated to the delivery of a molybdenum-containing or tungsten-containing precursor vapor and a second type of conduit is dedicated to the delivery of a reactant (e.g., H, NH, etc.). In these embodiments, the molybdenum-containing precursor and the reactant do not mix within the conduits before entering the processing chamber and do not share conduits when delivered sequentially to the chamber.

[0082] In some embodiments, a microvolume 707 is located below the showerhead 706. Performing ALD and / or CVD processes within a microvolume rather than the entire volume of the process station can reduce reactant exposure and cleaning time, reduce process condition (e.g., pressure, temperature, etc.) change time, and limit exposure of the process station robot to process gases. Examples of microvolume sizes include, but are not limited to, volumes of 0.1 to 2 liters. This microvolume also impacts production throughput. While the deposition rate per cycle is reduced, cycle time is simultaneously shortened. In certain cases, the latter effect is significant enough to increase the overall throughput of the module for a given target film thickness.

[0083] In some embodiments, the pedestal 708 may be raised or lowered to expose the substrate 712 to the microvolume 707 and / or to vary the volume of the microvolume 707. For example, during a substrate transfer phase, the pedestal 708 may be lowered to load the substrate 712 onto the pedestal 708. During a deposition process phase, the pedestal 708 may be raised to position the substrate 712 within the microvolume 707. In some embodiments, the microvolume 707 may completely surround the substrate 712 and a portion of the pedestal 708, creating a high flow impedance region during the deposition process.

[0084] Optionally, the pedestal 708 may be lowered and / or raised during portions of the deposition process to adjust the process pressure, reactant concentration, etc. within the microvolume 707. As an example, the process chamber body 702 may maintain a base pressure during the deposition process, thereby lowering the pedestal 708 to allow the microvolume 707 to be evacuated. Example ratios of the microvolume to the volume of the process chamber include, but are not limited to, volume ratios of 1:700 to 1:10. It will be appreciated that in some embodiments, the height of the pedestal may be programmatically adjusted by a suitable computer controller.

[0085] While reference is made herein to the use of an adjustable height pedestal as an example of varying the micro-volume, it is recognized that in some embodiments, the position of the showerhead 706 may be adjusted relative to the pedestal 708 to vary the volume of the micro-volume 707. It is further recognized that the vertical position of the pedestal 708 and / or the showerhead 706 may be varied by any suitable mechanism within the scope of the present disclosure. In some embodiments, the pedestal 708 may include a rotation axis for rotating the orientation of the substrate 712. It is recognized that in some embodiments, one or more of these adjustment examples may be performed programmatically by one or more suitable computer controllers.

[0086] Returning to the embodiment shown in FIG. 7 , the showerhead 706 and pedestal 708 are in electrical communication with an RF power source 714 and matching network 716 for powering the plasma. In other embodiments, an apparatus without a plasma generator is used to deposit molybdenum-containing and tungsten-containing films using the methods provided herein. In some embodiments, the plasma energy may be controlled by controlling one or more of the process station pressure, gas concentration, radio frequency (RF) source power, RF source frequency, and plasma power pulse timing. For example, the RF power source 714 and matching network 716 may operate at any suitable power to generate a plasma having a desired radical species composition. Similarly, the RF power source 714 may provide RF power at any suitable frequency. In some embodiments, the RF power source 714 may be configured to independently control high-frequency and low-frequency RF power sources. Examples of low RF frequencies include, but are not limited to, frequencies between 50 kHz and 700 kHz. Examples of high RF frequencies include, but are not limited to, frequencies between 1.8 MHz and 2.45 GHz. It is recognized that any suitable parameters may be adjusted, either discretely or continuously, to provide plasma energy for surface reactions. As a non-limiting example, the plasma power may be intermittently pulsed to reduce ion bombardment of the substrate surface compared to a continuously powered plasma. In some embodiments, the plasma is used to post-treat the deposited substantially carbon-free film.

[0087] In some embodiments, the plasma may be monitored in situ by one or more plasma monitors. As one example, plasma power may be monitored by one or more voltage and current sensors (e.g., VI probes). As another example, plasma density and / or process gas concentration may be measured by one or more optical emission spectroscopy (OES) sensors. In some embodiments, one or more plasma parameters may be programmably adjusted based on measurements from such in situ plasma monitors. For example, OES sensors may be used in a feedback loop to achieve programmable control of plasma power. It is recognized that in some embodiments, other monitors may be used to monitor the plasma and other process characteristics. Examples of such monitors include, but are not limited to, infrared (IR) monitors, acoustic monitors, and pressure transducers.

[0088] In some embodiments, the plasma may be controlled via Input / Output Control (IOC) sequence instructions. As an example, instructions for setting plasma conditions for a plasma process phase may be included in a corresponding plasma activation recipe phase in a deposition process recipe. In some cases, process recipe phases may be arranged sequentially, with all instructions for a deposition process phase executed simultaneously with that process phase. In some embodiments, instructions for setting one or more plasma parameters may be included in a recipe phase preceding a plasma process phase. For example, a first recipe phase may include instructions for setting inert and / or reactive gas flow rates, instructions for setting a plasma generator to a power setting, and a time delay instruction for the first recipe phase. A subsequent second recipe phase may include instructions for enabling the plasma generator and a time delay instruction for the second recipe phase. A third recipe phase may include instructions for disabling the plasma generator and a time delay instruction for the third recipe phase. It will be appreciated that these recipe phases may be further subdivided and / or iterated in any suitable manner within the scope of the present disclosure.

[0089] In some embodiments, the pedestal 708 may be temperature controlled via a heater 710. Additionally, in some embodiments, pressure control of the deposition process station 700 may be achieved by a butterfly valve 718. As shown in the embodiment of Figure 7, the butterfly valve 718 throttles the vacuum provided by a downstream vacuum pump (not shown). However, in some embodiments, pressure control of the process station 700 may be adjusted by varying the flow rate of one or more gases introduced to the process station 700.

[0090] FIG. 8 is a schematic diagram of one embodiment of a multi-station processing tool 800 including an input load lock 802 and an output load lock 804. One or both of the input load lock 802 and the output load lock 804 may be equipped with a remote plasma source. Such a tool may be used to process substrates according to the methods provided herein. A robot 806 is configured to transfer wafers from a cassette loaded via a pod 808 to the input load lock 802 through an atmospheric pressure port 810 at atmospheric pressure. The robot 806 places the wafer on a pedestal 812 in the input load lock 802, closes the atmospheric pressure port 810, and evacuates the load lock. If the input load lock 802 is equipped with a remote plasma source, the wafer may be subjected to a remote plasma treatment in the load lock before being introduced into the processing chamber 814. Additionally, the wafer may be heated in the input load lock 802, for example, to remove moisture and adsorbed gases. The chamber transfer port 816 to the processing chamber 814 is then opened, and another robot (not shown) moves the wafer into the reactor and places it on a pedestal in the first station shown in the reactor for processing. It is recognized that while the embodiment shown in Figure 8 includes a load lock, in some embodiments the wafer may be configured to enter the process station directly.

[0091] The illustrated processing chamber 814 includes four processing stations. In the embodiment shown in FIG. 8, the processing stations are numbered 1 through 4. Each station includes a heated pedestal (designated 818 in station 1) and a gas line inlet. It is recognized that in some embodiments, each processing station may have a different purpose or multiple purposes. While the illustrated processing chamber 814 includes four stations, it is understood that processing chambers according to the present disclosure may include any suitable number of stations. For example, in some embodiments, the processing chamber may include five or more stations, while in other embodiments, the processing chamber may include three or fewer stations.

[0092] FIG. 8 also illustrates an embodiment of a wafer handling system 890 for transporting wafers within the processing chamber 814. In some embodiments, the wafer handling system 890 may transport wafers between various process stations and / or between process stations and load locks. It is recognized that any suitable wafer handling system may be employed. Non-limiting examples include a wafer carousel and a wafer handling robot. FIG. 8 also illustrates an embodiment of a system controller 850 for controlling the process conditions and hardware states of the process tool 800. The system controller 850 may include one or more memory devices 856, one or more mass storage devices 854, and one or more processors 852. The processor 852 may include a CPU or computer, analog and / or digital input / output connections, stepper motor control boards, etc.

[0093] In some embodiments, system controller 850 controls all operation of process tool 800. System controller 850 executes system control software 858, which is stored on mass storage device 854, loaded into memory device 856, and executed on processor 852. System control software 858 may include instructions for controlling the timing, mixture of gases, chamber and / or station pressure, chamber and / or station temperature, purge conditions and timing, wafer temperature, RF power levels, RF frequency, substrate, pedestal, chuck and / or susceptor position, and other parameters of a particular process performed by process tool 800. System control software 858 may be configured in any suitable manner. For example, various process tool component subroutines or control objects may be written to control the operation of process tool components necessary to perform processes with various process tools in accordance with the methods of the present disclosure. System control software 858 may be coded in any suitable computer-readable programming language.

[0094] In some embodiments, system control software 858 may include input / output control (IOC) sequence instructions for controlling the various parameters described above. For example, each phase of an ALD process may include one or more instructions executed by system controller 850. Instructions for setting process conditions for an ALD process phase may be included in the corresponding ALD recipe phase. In some embodiments, ALD recipe phases may be arranged sequentially, where all instructions for an ALD process phase are executed simultaneously with that process phase.

[0095] In some embodiments, other computer software and / or programs stored on the mass storage device 854 and / or memory device 856 associated with the system controller 850 may be used. Examples of such programs or some of the programs include a substrate positioning program, a process gas control program, a pressure control program, a heater control program, and a plasma control program.

[0096] The substrate positioning program may include program code for process tool components used to load the substrate onto the pedestal 818 and control the spacing between the substrate and other parts of the process tool 800 .

[0097] The process gas control program may include code for controlling gas composition and flow rates, and may optionally include code for flowing gases to one or more process stations to stabilize the pressure in the process stations prior to deposition. The process gas control program may include code for controlling gas composition and flow rates within any of the ranges of the present disclosure. The pressure control program may include code for controlling the pressure in the process stations by, for example, adjusting throttle valves in the exhaust systems of the process stations, gas flows to the process stations, etc. The pressure control program may include code for maintaining the pressure in the process stations within any of the pressure ranges of the present disclosure.

[0098] The heater control program may include code for controlling current to a heating unit used to heat the substrate. Alternatively, the heater control program may control the supply of a heat transfer gas (such as helium) to the substrate. The heater control program may include instructions for maintaining the temperature of the substrate within any of the ranges of the present disclosure.

[0099] The plasma control program may include code for setting the RF power level and frequency applied to the process electrodes in one or more process stations, for example, using any of the RF power levels disclosed herein. The plasma control program may further include code for controlling the duration of each plasma exposure.

[0100] In some embodiments, a user interface may be provided associated with the system controller 850. The user interface may include a display screen, a graphical software representation of equipment and / or process conditions, and user input devices such as a pointing device, keyboard, touch screen, microphone, etc.

[0101] In some embodiments, the parameters adjusted by the system controller 850 may relate to process conditions. Non-limiting examples include process gas composition and flow rates, temperature, pressure, plasma conditions (RF power level, frequency, exposure time, etc.), etc. These parameters may be provided to the user as a recipe. The recipe may be input using a user interface.

[0102] Signals for monitoring the process may be provided from various process tool sensors via analog and / or digital input connections of the system controller 850. Signals for controlling the process may be output on analog and digital output connections of the process tool 800. Non-limiting examples of process tool sensors that may be monitored include mass flow controllers, pressure sensors (such as manometers), thermocouples, etc. Data from these sensors may be used in conjunction with appropriately programmed feedback and control algorithms to maintain process conditions.

[0103] Any suitable chamber may be used to practice embodiments of the present disclosure. Examples of deposition equipment include, but are not limited to, equipment from the Altus family of products manufactured by Lam Research Corp. (Fremont, Calif.), or any of a variety of other commercially available processing systems. Two or more stations may perform the same function. Similarly, two or more stations may perform different functions. Each station can be designed / configured to perform a particular function / method desired.

[0104] In some embodiments, the apparatus includes a processing chamber for depositing substantially carbon-free films and another processing chamber configured to treat these films with a remote plasma to densify the films, lower their resistivity, or increase their work function, hi some embodiments, the apparatus is programmed or configured to transfer the substrate from the deposition processing chamber to the plasma processing chamber without exposing the substrate to ambient atmosphere, moisture, or oxygen.

[0105] FIG. 9 is a block diagram of a processing system suitable for performing a thin film deposition process, according to certain embodiments. System 900 includes a transfer module 903, which provides a clean, pressurized environment to minimize contamination risks as substrates undergo processing are moved between various reactor modules. Transfer module 903 is equipped with two multi-station reactors 909 and 910, each capable of performing atomic layer deposition (ALD) and / or chemical vapor deposition (CVD) processes, according to certain embodiments. Reactors 909 and 910 may include multiple stations 911, 913, 915, and 917. Stations 911, 913, 915, and 917 may perform processes sequentially or non-sequentially, according to embodiments of the present disclosure. The stations may include a heated pedestal or substrate support and one or more gas inlets, showerheads, or distribution plates.

[0106] The transfer module 903 may also include one or more single- or multi-station modules 907 capable of performing plasma or chemical (non-plasma) pre-cleaning or other processes described in connection with the methods of the present disclosure. In some cases, the module 907 may be used for various processes to prepare substrates, for example, for deposition processes. The module 907 may also be designed / configured to perform various other processes, such as etching or polishing. The system 900 further includes one or more wafer source modules 901 where wafers are stored before and after processing. An atmospheric robot (not shown) in an atmospheric transfer chamber 919 may first retrieve wafers from the source module 901 to a load lock 921. A wafer transfer device (typically a robot arm unit) in the transfer module 903 moves wafers from the load lock 921 to and between modules mounted on the transfer module 903.

[0107] In various embodiments, a system controller 929 is used to control process conditions during deposition. The controller 929 typically includes 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, stepper motor control boards, etc.

[0108] The controller 929 may control all operations of the deposition apparatus. The system controller 929 executes system control software that includes instruction sets for controlling the timing, mixture of gases, chamber pressure, chamber temperature, wafer temperature, radio frequency (RF) power levels, 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 929 may also be used.

[0109] Typically, there is a user interface associated with the controller 929. The user interface may include a display screen, a graphical software representation of equipment and / or process conditions, and user input devices such as a pointing device, keyboard, touch screen, microphone, etc.

[0110] The system control logic may be configured in any suitable manner. In general, logic may be designed or configured as hardware and / or software. Instructions for controlling the drive circuitry may be hard-coded or provided as software. The instructions may be provided by "programming." Such programming is understood to include any form of logic, including hard-coded logic in digital signal processors, application-specific integrated circuits, and other devices that implement specific algorithms in hardware. Programming is also understood to include software or firmware instructions executable on a general-purpose processor. The system control software may be coded in any suitable computer-readable programming language.

[0111] The computer program code for controlling the flow of precursors and other processes in the process sequence can be written in any conventional computer-readable programming language (e.g., assembly language, C, C++, Pascal, Fortran, etc.). The compiled object code or script is executed by a processor to perform the tasks specified in the program. Also, as noted above, the program code may be hard-coded.

[0112] The controller parameters relate to process conditions such as, for example, process gas composition and flow rates, temperature, pressure, cooling gas pressure, substrate temperature, chamber wall temperature, etc. These parameters may be provided to a user as a recipe and entered using a user interface. Signals for monitoring the process may be provided via analog and / or digital input connections of the system controller 929. Signals for controlling the process are output on analog and digital output connections of the deposition apparatus 900.

[0113] The system software may 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 deposition processes (and possibly other processes) in accordance with embodiments of the present disclosure. Examples of programs or portions of programs for this purpose include substrate positioning code, process gas control code, pressure control code, and heater control code.

[0114] In some implementations, the controller 929 is part of a system, which may be part of the examples described above. Such systems may include semiconductor processing equipment, including one or more processing tools, one or more chambers, one or more processing platforms, and / or specific processing components (such as a wafer pedestal or gas flow system). These systems may be integrated with electronics for controlling the operation of the system before, during, and after processing of semiconductor wafers or substrates. The electronics may also be referred to as a "controller" and may control various components or subparts of one or more systems. The controller 929 may be programmed to control any of the processes disclosed herein, depending on the processing requirements and / or type of system. These processes may include supplying process gases, temperature settings (e.g., heating and / or cooling), pressure settings, vacuum settings, power settings, radio frequency (RF) generator settings in some systems, RF matching circuit settings, frequency settings, flow settings, fluid supply settings, position and motion settings, wafer loading and unloading from the tool, and wafer loading and unloading from other transport tools and / or load locks connected or associated with the particular system.

[0115] Broadly, a controller may be defined as an electronic device having various integrated circuits, logic, memory, and / or software to receive instructions, issue instructions, control operations, enable cleaning operations, enable endpoint measurements, etc. Integrated circuits may include chips defined as firmware that store program instructions, digital signal processors (DSPs), application-specific integrated circuits (ASICs), and / or one or more microprocessors or microcontrollers that execute program instructions (e.g., software). The program instructions may be instructions communicated to the controller as various individual settings (or program files) that define operational parameters for performing a particular process on or for a semiconductor wafer or for a system. In some embodiments, the operational parameters may be part of a recipe defined by a process engineer to accomplish one or more processing steps in the fabrication of one or more layers, materials, metals, oxides, silicon, silicon dioxide, surfaces, circuits, and / or wafer dies.

[0116] In some implementations, the controller may be part of or coupled to a computer, where the computer may be integrated with the system, coupled to the system, or otherwise networked with the system, or a combination thereof. For example, the controller may reside in the “cloud” or in all or part of a fab host computer system. This enables remote access to wafer processing. The computer may enable remote access to the system to monitor the progress of a manufacturing process, examine past manufacturing process history, or examine trends or performance indicators from multiple manufacturing processes, modify parameters for a current process, configure subsequent processing steps, or initiate a new process. In some examples, a process recipe may be provided to the system from a remote computer (e.g., a server) over a network, where the network may include a local network or the Internet. The remote computer may include a user interface that allows input or programming of parameters and / or settings. These parameters and / or settings are then communicated from the remote computer to the system. In some examples, the controller receives instructions as data, which specifies parameters for each processing step to be performed in one or more operations. It should be understood that these parameters may be specific to the type of process being performed and the type of tool the controller is configured to cooperate with or control. Thus, as described above, the controller may be distributed, such as by having one or more individual controllers that are networked and operate toward a common purpose, such as the process and control described herein. An example of a distributed controller for such a purpose includes one or more integrated circuits mounted in the chamber that communicate with one or more integrated circuits located remotely (e.g., at the platform level or as part of a remote computer).These integrated circuits work together to control the process in the chamber.

[0117] Non-limiting examples of systems include a plasma etch chamber or module, a deposition chamber or module, a spin rinse chamber or module, a metal plating chamber or module, a cleaning chamber or module, a bevel edge etch chamber or module, a physical vapor deposition (PVD) chamber or module, a chemical vapor deposition (CVD) chamber or module, an atomic layer deposition (ALD) chamber or module, an atomic layer etch (ALE) chamber or module, an ion implantation chamber or module, a track chamber or module, and any other semiconductor processing system that may be associated with or usable in the manufacturing and / or production of semiconductor wafers.

[0118] As described above, depending on one or more process steps being performed by the tool, the controller may communicate with one or more of other tool circuits or tool modules, other tool components, cluster tools, other tool interfaces, adjacent tools, nearby tools, tools located throughout the factory, a main computer, another controller, or tools used in material transport to and from tool locations and / or load ports within a semiconductor manufacturing factory.

[0119] [Flow Mixer] In another aspect, a flow mixer is provided for mixing a carrier gas and a metal-containing precursor prior to delivery to a processing chamber. The flow mixers described herein are adapted to improve uniformity in delivering the metal-containing precursor to the showerhead and can be used with any metal-containing precursor, including, but not limited to, the molybdenum and tungsten precursors described herein.

[0120] Examples of Mo-containing precursors for ALD or CVD of molybdenum or molybdenum-containing materials include MoF6, MoCl5, molybdenum dioxide dichloride (MoO2Cl2), molybdenum oxide tetrachloride (MoOCl4), and molybdenum hexacarbonyl (Mo(CO)6). Other examples include Mo x O x H z Mo oxyhalides have the formula: where H is a halogen (fluorine (F), chlorine (Cl), bromine (Br), or iodine (I)), and x, y, and z are any numbers greater than zero that can form a stable molecule. These include molybdenum tetrafluoride oxide (MoOF), molybdenum dioxide dibromide (MoOBr), and molybdenum oxyiodides MoOI, MoO 11 I. Organometallic precursors may also be used, examples of which include Mo precursors with cyclopentadienyl ligands. Further examples include Mo2L n Precursors having the formula: Mo2L, where each L is independently selected from amidate, amidinate, and guanidinate ligands, and n is 2 to 5. nThe precursor contains multiple molybdenum-molybdenum bonds (e.g., double bonds or any multiple bonds having bond orders of 2 to 5). Further examples include halide-containing heteroleptic molybdenum compounds (i.e., compounds with different types of ligands). Specific examples of such precursors include compounds containing molybdenum, at least one halide that forms a bond with the molybdenum, and at least one organic ligand containing any of the elements N, O, and S, where any atom of these elements forms a bond with the molybdenum. Examples of suitable organic ligands providing nitrogen or oxygen bonds include amidinates, amidates, iminopyrrolidinates, diazadienes, β-iminoamides, α-iminoalkoxides, β-aminoalkoxides, β-diketoiminates, β-ketoiminates, β-diketonates, amines, and pyrazolates. Examples of suitable organic ligands providing sulfur bonds include thioethers, thiolates, dithiolenes, dithiolates, and α-iminothiolenes. These ligands may be substituted or unsubstituted. In some embodiments, these ligands contain one or more substituents independently selected from the group consisting of H, alkyl, fluoroalkyl, alkylsilyl, alkylamino, and alkoxy substituents. The organic ligands can be neutral or anionic (e.g., monoanionic or dianionic), and the molybdenum can be in various oxidation states, such as +1, +2, +3, +4, +5, and +6.

[0121] When metal precursor vapor is delivered to the showerhead, it is typically mixed with a flow of carrier gas, such as N2, argon, or helium, to achieve the desired concentration of precursor. This mixing typically occurs in a flow mixer with an outlet connected to the showerhead. Note that in many embodiments, the metal precursor vapor is delivered to the mixing tube with a first flow of carrier gas and then diluted with a second flow of carrier gas. For clarity, the flow of this higher concentration of metal-containing precursor in the carrier gas will be referred to as the metal precursor flow, and the flow of carrier gas without the precursor will be referred to as the carrier gas flow.

[0122] One problem that can arise when these flows mix is ​​uneven delivery of the metal precursor to the showerhead. For example, peripheral regions near the edges of the showerhead may have a lower concentration of the metal precursor in the received flow than regions closer to the center of the showerhead. This can result in uneven distribution of the metal precursor within the processing chamber. A flow mixer configured to improve the uniformity of mixing of the metal precursor and the carrier gas is provided. In some embodiments, the flow mixer delivers the metal precursor such that the metal precursor concentration at all showerhead outlets is within 2% by volume. In implementations described herein, the flow mixer includes: (a) an outer fluid conduit, the outer fluid conduit having an inlet for flowing a carrier gas into the outer fluid conduit, a mixing zone for mixing the carrier gas with the metal-containing precursor, and an outlet for discharging the carrier gas mixed with the metal-containing precursor from the outer fluid conduit; and (b) an inner fluid conduit at least partially disposed within the outer fluid conduit. wherein the inner fluid conduit comprises an inlet for flowing the metal-containing precursor into the inner fluid conduit and an outlet configured to discharge the metal-containing precursor into the outer fluid conduit, wherein the distance from the inlet of the inner fluid conduit to the inlet of the outer fluid conduit is greater than the distance from the outlet of the inner fluid conduit to the inlet of the outer fluid conduit, thereby enabling counter-flow of the carrier gas and the metal-containing precursor in the flow mixer, wherein the distance refers to the distance in the z-direction.

[0123] A flow mixer described herein is shown in FIG. 10 . FIG. 10 illustrates a schematic side view of a flow mixer 1001 and a cross-section of an inlet portion of an inner fluid conduit. Referring to FIG. 10 , an outer fluid conduit 1003 has a generally cylindrical shape and includes an inlet (not shown) at the top of the outer fluid conduit 1003 for introducing a carrier gas. The inlet of the outer fluid conduit is connected to a carrier gas source. The flow of the carrier gas (without the metal precursor) is indicated by a downward arrow 1005. An outlet 1007 of the outer fluid conduit 1003 is located at the bottom of the outer fluid conduit 1003, opposite the inlet. The outlet is adapted to connect to a showerhead (not shown) and to supply a mixed flow 1009 of the carrier gas and the metal-containing precursor to the showerhead. An inner fluid conduit 1011 is located (at least partially) inside the outer fluid conduit and has a portion coaxial with the outer fluid conduit 1003. The inner fluid conduit 1011 has an inlet 1013 configured to receive a metal precursor from a metal precursor source. The metal precursor is typically mixed with a carrier gas before entering the inner fluid conduit; however, this flow has a higher metal precursor concentration than the target concentration at the showerhead and therefore requires further dilution with carrier gas within the mixing tube. The metal precursor flow entering the inner fluid conduit 1011 is indicated by arrow 1015. The outlet 1017 of the inner fluid conduit 1011 is configured to discharge the metal-containing precursor flowing upward, as indicated by arrow 1019, into the outer fluid conduit 1003. In the outer fluid conduit 1003, the metal precursor flow is mixed with the carrier gas flow. Notably, the distance 1018 in the z-direction (vertical direction) from the inlet 1013 of the inner fluid conduit 1011 to the outlet 1017 of the inner fluid conduit 1011 is less than the distance from the inlet 1013 of the inner fluid conduit 1011 to the inlet (not shown) of the outer fluid conduit 1003 located at the top of the outer fluid conduit 1003. This configuration allows for counter-flow of the carrier gas (indicated by downward arrow 1005) and the metal-containing precursor (indicated by upward arrow 1019), resulting in more efficient flow mixing.

[0124] The outer fluid conduit 1003 includes a mixing zone 1021. In the mixing zone 1021, the metal-containing precursor flow and the carrier gas flow mix without restriction, forming a mixed flow, as indicated by the downward arrow 1023. Because mixing in this zone affects the uniformity of precursor concentrations within the showerhead, it is important to provide a mixing zone of an appropriate length. In some embodiments, the length of the mixing zone L1 in the z-direction is at least about 102 mm (e.g., at least about 127 mm). For example, with a flow rate of 1,000 sccm and an outer diameter of the outer tube of about 41 mm, a mixing zone of 102 mm length provides adequate mixing. In some embodiments, the ratio of the length L1 of the flow mixing zone in the z-direction to the inner diameter of the outer fluid conduit 1003 is at least about 2, e.g., at least about 3.

[0125] In some embodiments, such as the embodiment shown in FIG. 10 , the outer fluid conduit 1003 further includes a restriction zone 1025. In the restriction zone 1025, the combined flow 1023 is restricted to a plurality of narrower flow paths located within the outer fluid conduit 1003. For example, in some embodiments, the restriction zone includes six narrower, non-communicating flow paths that convey the combined flow to the outlet 1007. The restriction zone has a length L2 (e.g., about 1-5 mm) in the z-direction. The combined flow in the restriction zone is indicated by a downward arrow 1027.

[0126] In some embodiments, the flow mixer 1001 is designed such that the outlet 1017 from the inner fluid conduit 1013 includes a flow redirector 1029. The flow redirector 1029 is configured to redirect the metal-containing precursor flow before it mixes with the carrier gas flow in the outer fluid conduit 1003, such that the redirected metal-containing precursor flow has a velocity component that is opposite to the velocity direction of the carrier gas flow in the outer fluid conduit.

[0127] The flow redirector may include two parallel flow restriction plates configured to restrict the metal-containing precursor flow between them. For example, the upward flow of the metal-containing precursor is turned laterally by less than 90 degrees, thereby maintaining a velocity component opposite to the downward direction of the carrier gas flow. Maintaining this opposing velocity component is an important factor in improving mixing efficiency. In some embodiments, the flow redirector 1029 includes a feed tee with multiple (e.g., six) equally spaced radial openings.

[0128] In some implementations, the ratio of the inner diameter of the outer fluid conduit to the inner diameter of the inner fluid conduit is about 1.5 to 10 (e.g., about 1.5 to 5). As a specific example, the inner diameter of the outer fluid conduit is about 40.5 mm, and the inner diameter of the inner fluid conduit is about 4.8 mm. In some implementations, the flow mixer has an overall length in the z-direction of about 76 to 510 mm (e.g., about 102 to 508 mm, e.g., about 124.5 mm). The flow mixer can be formed from a variety of materials compatible with metal-containing precursors, such as aluminum, stainless steel, and ceramic.

[0129] [Multiple plenum shower head] In another aspect, a multi-plenum showerhead for delivering multiple reactants to a processing chamber is provided. The showerhead may be used to deliver any combination of reactants, including, but not limited to, the molybdenum-containing precursors and tungsten-containing precursors described herein. In some embodiments, the multi-plenum showerhead includes: (a) a showerhead faceplate having a first plurality of conduits for delivering a first reactant and a second plurality of conduits for delivering a second reactant, the first plurality of conduits being fluidly isolated from the second plurality of conduits; and (b) a showerhead housing disposed around the periphery of the showerhead faceplate, to which the showerhead faceplate is removably attached. Because the showerhead is configured with a removable faceplate, cleaning of the faceplate, which often has very small flow channels, can be efficiently performed. For example, the faceplate may be cleaned using a solvent by immersing the faceplate in the solvent and / or purging the flow channels with the solvent. In some embodiments, the faceplate has openings with a diameter of about 1 mm or less (such as 0.5 mm or less), which can be efficiently cleaned after the faceplate is removed from the base.

[0130] In some embodiments, the multi-plenum showerhead is a dual-plenum showerhead, where a first plurality of conduits is configured to deliver reactants (e.g., H, NH, SiH, BH, hydrocarbons, etc.) and a second plurality of conduits is configured to deliver metal-containing precursors (e.g., molybdenum-containing precursors or tungsten-containing precursors). FIG. 11A illustrates a portion of a dual-plenum showerhead 1101. The dual-plenum showerhead 1101 includes a faceplate 1103 and a housing 1105 attached to the faceplate 1103. The housing 1105 is disposed around the periphery of the faceplate 1103. The top of the faceplate 1103 includes multiple openings for conduits 1107 configured to deliver the metal-containing precursor through the faceplate. The metal-containing precursor is delivered downward into the faceplate and is confined by the showerhead housing on the side. The faceplate 1103 further includes multiple fluid conduits 1106. The fluid conduit 1106 is not in fluid communication with the metal precursor conduit 1107. The conduit 1106 is configured to receive reactants (e.g., H2, NH3, etc.) from a reactant supply annulus 1109 disposed within the housing 1105 and distribute the reactants laterally through the showerhead faceplate 1103. The reactant conduit 1106 has multiple outlets (not shown) on the bottom surface of the faceplate 1103 configured to deliver the reactants to the processing chamber. In some embodiments, the outlets have a diameter of about 1 mm or less, or 0.5 mm or less. The outlets of both the metal precursor conduit and the reactant conduit open into the processing chamber. The conduits are designed so that the metal precursor and the reactants do not contact each other within the body of the showerhead 1101.

[0131] The showerhead faceplate 1103 serves to distribute the metal precursor and reactants to the processing chamber without mixing them, while the showerhead housing 1105 serves to limit the volume above the showerhead faceplate 1103 for the metal precursor and to house a supply annulus 1109 configured to supply reactants to the reactant conduits 1106 of the showerhead faceplate 1103. Reactant flow is indicated by arrows 1110. The housing can further include a heater 1111. The heater 1111 may be annular and recessed in a recess formed in the housing. Typically, the housing also includes a ledge 1113 that supports an O-ring or other sealing member for sealing the showerhead to the metal precursor supply line. FIG. 11B illustrates the showerhead faceplate 1103 and showerhead housing 1105 after the faceplate 1103 has been removed from the housing 1105 (e.g., for cleaning). Removable fasteners 1115 are also shown in this figure. The fasteners 1115 are configured to fit into openings in the housing 1105 and are configured to removably attach the housing 1105 to the faceplate 1103 using openings in the perimeter of the faceplate 1103 .

[0132] The showerhead faceplate can be made from any material that is compatible with metal-containing precursors, such as aluminum, stainless steel, or ceramic materials.

[0133] [Further implementations] The apparatus and processes described herein may be used in combination with lithographic patterning tools or processes for, for example, manufacturing or producing semiconductor devices, displays, LEDs, solar panels, and the like. Typically (though not necessarily), such apparatus and processes are used or performed together in a common manufacturing facility. Lithographic patterning of a film typically includes some or all of the following steps, each of which can be performed by many available tools: (1) applying photoresist to a workpiece, i.e., substrate, using a spin-on or spray-on tool; (2) curing the photoresist using a hotplate, furnace, or UV curing device; (3) exposing the photoresist to visible light, ultraviolet light, extreme ultraviolet light, or X-rays using a tool such as a wafer stepper; (4) developing the resist to selectively remove the resist to form a resist pattern using a tool such as a wet bench; (5) transferring the resist pattern to an underlying film or workpiece using a dry etching tool or a plasma etching tool; and (6) removing the resist using a tool such as an RF plasma or microwave plasma resist stripper.

Claims

1. 1. A method for forming a substantially carbon-free metal-containing layer on a semiconductor substrate, comprising: (a) introducing a metal-containing precursor into a process chamber containing the semiconductor substrate, the metal-containing precursor being a halide- and carbonyl-free compound having at least one ligand bonded to a metal selected from the group consisting of molybdenum and tungsten, the halide- and carbonyl-free compound being free of metal-carbon and metal-oxygen double bonds; (b) reacting the metal-containing precursor with at least one reactant in the absence of a plasma to form a metal-containing layer on the semiconductor substrate, wherein the formed metal-containing layer is a substantially carbon-free molybdenum- or tungsten-containing layer having a carbon content of less than about 5 atomic %, the layer being selected from the group consisting of Mo, W, MoN, WN, MoON, WON, MoB, WB, MoSi, WSi layers, and combinations thereof; A method comprising:

2. 10. The method of claim 1, the formed metal-containing layer has a carbon content of less than about 2 atomic percent; method.

3. 10. The method of claim 1, The metal-containing precursor does not contain a β-hydrogen atom; method.

4. 10. The method of claim 1, the formed metal-containing layer is selected from the group consisting of Mo, MoN, and MoON; method.

5. 10. The method of claim 1, the metal-containing precursor is selected from the group consisting of Precursors 1-16, wherein each of R and R1 is independently selected from the group consisting of alkyl, fluoroalkyl, and alkylsilyl, R does not contain a β-hydrogen bond, n is 1-4, and m is 1-4; method.

6. 10. The method of claim 1, The metal-containing precursor is a compound selected from compounds 17 to 20. method.

7. 10. The method of claim 1, (c) treating the formed metal-containing layer with a nitrogen-containing reactant to increase the nitrogen content in the metal-containing layer; method.

8. 8. The method of claim 7, the treated metal-containing layer is a MoN layer having a work function greater than about 4.9 eV; method.

9. 8. The method of claim 7, the treated metal-containing layer is a MoN layer having a nitrogen content of at least about 25 atomic percent; method.

10. 8. The method of claim 7, the treated metal-containing layer is a MoN layer having a work function greater than about 5.0 eV; method.

11. 8. The method of claim 7, step (c) comprising treating the semiconductor substrate with a plasma formed in a process gas including the nitrogen-containing reactant; method.

12. 10. The method of claim 1, (c) treating the formed metal-containing layer with H 2 densifying the formed metal-containing layer by treating it with a plasma formed in a process gas comprising method.

13. 10. The method of claim 1, In step (b), the reaction between the metal-containing precursor and the at least one reactant occurs on a surface of the semiconductor substrate. method.

14. 14. The method of claim 13, The step (a) forming a layer of the metal-containing precursor on the surface of the semiconductor substrate and removing any non-surface-bound metal-containing precursor from the processing chamber; The step (b) introducing the at least one reactant into the processing chamber to react with the metal-containing precursor on the surface of the semiconductor substrate. method.

15. 10. The method of claim 1, the substantially carbon-free metal-containing layer is a diffusion barrier layer or a liner layer; method.

16. 10. The method of claim 1, The method includes forming the substantially carbon-free metal-containing layer in a pMOS device, the metal-containing layer having a work function greater than about 5.0 eV. method.

17. 10. The method of claim 1, forming the substantially carbon-free metal layer having a work function greater than about 5.0 eV comprises treating the semiconductor substrate after step (b) with a plasma-activated nitrogen-containing reactant to increase the nitrogen content in the metal-containing layer. method.

18. 10. The method of claim 1, The substantially carbon-free metal layer is formed in step (b) at a temperature of less than about 450°C. method.

19. 10. The method of claim 1, The method includes repeating steps (a) and (b), and includes performing a cycle including steps (a) and (b) about 1 to 100 times. method.

20. 10. The method of claim 1, The at least one reactant is H 2 , N.H. 3 , and N 2 H 4 selected from the group consisting of method.

21. 10. The method of claim 1, The step (b) is a step of treating the metal-containing precursor with H 2 reacting with method.

22. A semiconductor device, a metal-containing liner layer that is substantially free of carbon; The metal is selected from the group consisting of molybdenum and tungsten, the carbon content in the substantially carbon-free metal-containing layer is less than about 3 atomic %, and the substantially carbon-free metal liner layer has a thickness of less than about 50 Å and a surface area of ​​less than about 3,000 μcm -1 and the dielectric layer has a resistivity less than 100 .mu.m and is disposed between the dielectric layer and the conductive layer. Semiconductor device.

23. 22. The semiconductor device according to claim 21, the substantially carbon-free metal-containing layer is a diffusion barrier layer; Semiconductor device.

24. 22. The semiconductor device according to claim 21, The substantially carbon-free metal-containing layer has a surface area of ​​about 1,000 μcm -1 having a resistivity less than Semiconductor device.

25. 22. The semiconductor device according to claim 21, The substantially carbon-free metal-containing layer has a surface area of ​​about 600 μcm -1 having a resistivity less than Semiconductor device.

26. 22. The semiconductor device according to claim 21, the metal-containing layer substantially free of carbon is a Mo layer or a MoN layer; Semiconductor device.

27. A semiconductor device, a gate electrode; the gate electrode comprises a substantially carbon-free metal-containing layer, wherein the carbon content in the substantially carbon-free metal-containing layer is less than about 3 atomic %, the substantially carbon-free metal-containing layer having a work function greater than 4.9 eV and comprising a metal selected from the group consisting of molybdenum and tungsten; Semiconductor device.

28. 28. The semiconductor device according to claim 27, the substantially carbon-free metal-containing layer is a MoN layer; Semiconductor device.

29. 28. The semiconductor device according to claim 27, the substantially carbon-free metal-containing layer has a work function greater than about 5.0 eV; Semiconductor device.

30. 28. The semiconductor device according to claim 27, the substantially carbon-free metal-containing layer has a thickness of about 5 to 50 Å; Semiconductor device.

31. 28. The semiconductor device according to claim 27, the semiconductor device is a pMOS device selected from the group consisting of a planar pMOS device, a FinFET pMOS device, and a gate-all-around (GAA) pMOS device; Semiconductor device.

32. 1. An apparatus for forming a substantially carbon-free metal-containing layer on a semiconductor substrate, comprising: (a) a deposition processing chamber having a substrate support pedestal, an inlet for introducing a metal-containing precursor, and a second inlet for introducing at least one reactant; (b) a plasma processing chamber distinct from the deposition processing chamber, the plasma processing chamber having a substrate support pedestal and an inlet for introducing plasma processing reactants; (c) a controller including program instructions, the program instructions comprising: (i) instructions for generating a surface-limited reaction of a metal-containing precursor and at least one reactant in the deposition processing chamber in the absence of a plasma to form a layer of substantially carbon-free metal-containing material, wherein the metal is selected from the group consisting of molybdenum and tungsten; (ii) instructions for transferring the semiconductor substrate from the deposition processing chamber to the plasma processing chamber without exposure to an ambient atmosphere; (iii) instructions for treating the substantially carbon-free metal-containing material with a plasma-activated plasma treatment reactant; 1. An apparatus comprising:

33. 33. The apparatus of claim 32, The plasma treatment reactants may be nitrogen-containing reactants and / or H 2 and said instruction (iii) is to react said nitrogen-containing reactant and / or H 2 and instructions for forming a remote plasma in a process gas comprising: Device.

34. 1. A flow mixer for mixing a carrier gas and a metal-containing precursor, comprising: (a) an outer fluid conduit comprising: an inlet for allowing the carrier gas to enter the outer fluid conduit; a mixing zone for mixing the carrier gas with the metal-containing precursor; and an outlet for discharging the carrier gas mixed with the metal-containing precursor from the outer fluid conduit; (b) an inner fluid conduit disposed at least partially within the outer fluid conduit, the inner fluid conduit comprising an inlet for allowing the metal-containing precursor to enter the inner fluid conduit and an outlet configured to release the metal-containing precursor into the outer fluid conduit; a distance from the inlet of the inner fluid conduit to the inlet of the outer fluid conduit is greater than a distance from the outlet of the inner fluid conduit to the inlet of the outer fluid conduit, thereby enabling counter-flow of the carrier gas and the metal-containing precursor within the flow mixer, the distance being in the z-direction; Flow mixer.

35. 35. The flow mixer of claim 34, the outlet of the inner fluid conduit comprises a flow redirector configured to redirect the flow of the metal-containing precursor before the flow of the metal-containing precursor mixes with the flow of the carrier gas in the outer fluid conduit, whereby the redirected flow of the metal-containing precursor maintains a velocity component opposite to a velocity direction of the flow of the carrier gas in the outer fluid conduit; Flow mixer.

36. 36. The flow mixer of claim 35, the flow redirector includes two parallel flow restriction plates configured to restrict the flow of the metal-containing precursor between the plates; Flow mixer.

37. 35. The flow mixer of claim 34, the flow mixing zone having a length in the z-direction of at least about 127 mm; Flow mixer.

38. 35. The flow mixer of claim 34, the ratio of the z-direction length of the flow mixing zone to the inner diameter of the outer fluid conduit is at least 2; Flow mixer.

39. 35. The flow mixer of claim 34, the ratio of the z-direction length of the flow mixing zone to the inner diameter of the outer fluid conduit is at least 3; Flow mixer.

40. 35. The flow mixer of claim 34, the outer fluid conduit further includes a restriction zone downstream of the mixing zone, the restriction zone configured to restrict the mixed flow to a plurality of non-communicating conduits. Flow mixer.

41. 35. The flow mixer of claim 34, the outer fluid conduit and the inner fluid conduit include substantially coaxial portions; Flow mixer.

42. 35. The flow mixer of claim 34, the ratio of the inner diameter of the outer fluid conduit to the inner diameter of the inner fluid conduit is between about 1.5 and 10; Flow mixer.

43. 35. The flow mixer of claim 34, The inner diameter of the outer fluid conduit is approximately 40.5 mm and the inner diameter of the inner fluid conduit is approximately 4.8 mm. Flow mixer.

44. 35. The flow mixer of claim 34, the flow mixer having a length in the z-direction of about 102 to 508 mm; Flow mixer.

45. 35. The flow mixer of claim 34, the flow mixer is comprised of a material selected from the group consisting of aluminum, stainless steel, and ceramic; Flow mixer.

46. 35. The flow mixer of claim 34, the outlet of the outer fluid conduit is configured to be connected to a showerhead of a deposition apparatus. Flow mixer.

47. 1. A deposition apparatus for depositing a metal-containing layer, comprising:

35. A flow mixer comprising the flow mixer of claim 34. Deposition equipment.

48. 1. A method for depositing a metal-containing layer on a semiconductor substrate, comprising: (a) mixing a metal-containing precursor with a carrier gas in a flow mixer according to claim 34; (b) delivering the resulting mixture to a process chamber and reacting the metal-containing precursor with a reactant to form the metal-containing layer on the semiconductor substrate; A method comprising:

49. 1. A multi-plenum showerhead for delivering multiple reactants to a processing chamber, comprising: (a) a showerhead faceplate comprising a first plurality of conduits for supplying a first reactant and a second plurality of conduits for supplying a second reactant, the first plurality of conduits configured to be fluidly isolated from the second plurality of conduits; (b) a showerhead housing disposed around an outer periphery of the showerhead faceplate, the showerhead housing to which the showerhead faceplate is removably attached; and Including, multi-plenum shower heads.

50. 50. The multi-plenum showerhead of claim 49, the showerhead includes a plurality of fasteners configured to removably attach the showerhead faceplate to the showerhead housing. Multi-plenum shower head.

51. 50. The multi-plenum showerhead of claim 49, the first plurality of conduits include openings less than about 1 mm in diameter; Multi-plenum shower head.

52. 50. The multi-plenum showerhead of claim 49, the first plurality of conduits include openings having a diameter of about 0.5 mm; Multi-plenum shower head.

53. 50. The multi-plenum showerhead of claim 49, The multi-plenum showerhead is a dual-plenum showerhead. Multi-plenum shower head.

54. 50. The multi-plenum showerhead of claim 49, the showerhead housing includes conduits in fluid communication with a first plurality of conduits of the showerhead faceplate. Multi-plenum shower head.

55. 50. The multi-plenum showerhead of claim 49, the showerhead housing includes a heater; Multi-plenum shower head.

56. 50. The multi-plenum showerhead of claim 49, the faceplate is comprised of a material selected from the group consisting of aluminum, stainless steel, and ceramic; Multi-plenum shower head.

57. 1. A faceplate for a showerhead for a deposition apparatus, comprising: the faceplate includes a first plurality of conduits for supplying a first reactant and a second plurality of conduits for supplying a second reactant, the first plurality of conduits configured to be fluidly isolated from the second plurality of conduits, and the faceplate configured to be removably attached to a showerhead housing. Faceplate.

58. 1. A deposition apparatus for depositing a metal-containing layer on a semiconductor substrate, comprising:

50. The multi-plenum showerhead of claim 49, Deposition equipment.

59. 10. The method of claim 1, applying a photoresist to the semiconductor substrate; exposing the photoresist to light; forming a pattern of the photoresist and transferring the pattern to the semiconductor substrate; selectively removing the photoresist from the semiconductor substrate; The method further comprises:

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