Method for depositing a molybdenum nitride film and semiconductor device structure including a molybdenum nitride film

Abstract

A method for depositing a molybdenum nitride film on a substrate surface is disclosed. The method may include: providing a substrate into a reaction chamber; and directly depositing a molybdenum nitride film on the substrate surface by performing one or more unit deposition cycles of a cyclic deposition process, wherein a unit deposition cycle may include contacting the substrate with a first gaseous reactant comprising a molybdenum halide precursor and contacting the substrate with a second gaseous reactant comprising a nitrogen precursor. A semiconductor device structure including a molybdenum nitride film is also disclosed.

Description

[0001] Cross - Reference to Related Applications

[0002] This application claims priority to U.S. Provisional Patent Application No. 62 / 891,254, filed on August 23, 2019, and titled "Method of Depositing a Molybdenum Nitride Film on a Substrate Surface by a Cyclic Deposition Process and Related Semiconductor Device Structures Including the Molybdenum Nitride Film", which is incorporated herein by reference. This application relates to U.S. Provisional Patent Application No. 62 / 891,247, filed on August 23, 2019, and titled "Method of Forming a Polycrystalline Molybdenum Film on a Substrate Surface and Related Structures Including the Polycrystalline Molybdenum Film", the entire content of which is incorporated herein by reference. Technical Field

[0003] The present disclosure generally relates to methods for depositing a molybdenum nitride film on a substrate surface, particularly methods for depositing a molybdenum nitride film by a cyclic deposition process. The present disclosure also generally relates to semiconductor device structures including a molybdenum nitride film. Background Art

[0004] Complementary metal oxide semiconductor (CMOS) technology typically utilizes n-type and p-type polysilicon as gate electrode materials. However, doped polysilicon may not be an ideal gate electrode material for advanced technology nodes. For example, although doped polysilicon is conductive, there may still be surface regions that can consume carriers under bias. Such consumed regions can manifest as an additional gate insulator thickness, commonly referred to as gate depletion, and may affect the equivalent oxide thickness. Although the gate depletion region may be thin, on the order of a few angstroms However, it may become significant as the gate oxide thickness decreases in advanced technology nodes. Additionally, polysilicon does not exhibit an ideal effective work function (eWF) for either NMOS or PMOS devices. To overcome the non-ideal effective work function of doped polysilicon, threshold voltage adjustment implants can be utilized. However, due to the reduction in device geometries in advanced technology nodes, the threshold voltage adjustment implant process may become increasingly complex.

[0005] To overcome the problems associated with doped polysilicon gate electrodes, non-ideal doped polysilicon gate materials can be replaced with alternative materials such as metals, metal nitrides, and metal carbides. For example, the properties of metal nitride films can be used to provide a more ideal effective work function for NMOS and PMOS devices, where the effective work function of the gate electrode, i.e., the energy requirement to extract electrons, can be compatible with the barrier height of the semiconductor material. For example, in the case of a PMOS device, the effective work function is approximately 5.0 - 5.2 eV, and in the case of an NMOS device, the effective work function is approximately 4.1 - 4.3 eV.

[0006] Accordingly, there is a need for a method for forming a low-resistivity gate electrode for NMOS and PMOS devices having a preferred effective work function. SUMMARY OF THE INVENTION

[0007] This summary is provided to introduce a series of concepts in a simplified form. These concepts are described in more detail below in the detailed description of example embodiments of the present disclosure. This summary is not intended to identify key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter.

[0008] In some embodiments, a method of depositing a molybdenum nitride film on a substrate surface by a cyclic deposition process is provided. The method may include: providing a substrate into a reaction chamber; and directly depositing a molybdenum nitride film on the substrate surface by performing one or more unit deposition cycles of the cyclic deposition process, wherein a unit deposition cycle includes: contacting the substrate with a first gaseous reactant comprising a molybdenum halide precursor; and contacting the substrate with a second gaseous reactant comprising a nitrogen precursor.

[0009] In some embodiments of the present disclosure, a semiconductor device structure including a molybdenum nitride film is provided. The semiconductor device structure of the present disclosure may include: a semiconductor channel region; and a gate stack structure directly disposed on the semiconductor channel region, wherein the gate stack structure includes: a gate dielectric directly disposed on the semiconductor channel region; and a molybdenum nitride film directly disposed on the gate dielectric.

[0010] For the purposes of summarizing the present invention and the advantages achieved over the prior art, certain objectives and advantages of the present invention are described above in the foregoing. Of course, it should be understood that not necessarily all such objectives or advantages can be achieved in any particular embodiment of the present invention. Thus, for example, those skilled in the art will recognize that the present invention may be embodied or practiced in a manner that achieves or optimizes one advantage or a group of advantages taught or suggested herein, without necessarily achieving other objectives or advantages that may be taught or suggested herein.

[0011] All of these embodiments are intended to be within the scope of the present invention as disclosed. To those skilled in the art, these and other embodiments will become apparent from the following detailed description of certain embodiments with reference to the accompanying drawings, and the present invention is not limited to any particular embodiment disclosed. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Although this specification concludes with claims that specifically identify and distinctly claim the subject matter regarded as embodiments of the present invention, the advantages of the embodiments of the present disclosure may be more readily determined from a description of certain examples of the embodiments of the present disclosure when read in conjunction with the accompanying drawings, in which:

[0013] Figure 1Shows an exemplary process flow that demonstrates a cyclic deposition process for depositing a molybdenum nitride film according to an embodiment of the present disclosure;

[0014] Figure 2 Shows an exemplary process flow that demonstrates another cyclic deposition process for depositing a molybdenum nitride film according to an embodiment of the present disclosure;

[0015] Figure 3 Shows an exemplary process flow that demonstrates yet another cyclic deposition process for depositing a molybdenum nitride film according to an embodiment of the present disclosure;

[0016] Figure 4 Shows the resistivity of multiple molybdenum nitride films with various thicknesses deposited according to an embodiment of the present disclosure;

[0017] Figure 5 Shows the resistivity of multiple molybdenum nitride films with varying thicknesses directly deposited on a dielectric compared to the resistivity of titanium nitride films with varying thicknesses deposited using a titanium tetrachloride precursor;

[0018] Figure 6 Shows x-ray diffraction (XRD) data obtained from an exemplary molybdenum nitride film deposited according to an embodiment of the present disclosure;

[0019] Figure 7 Shows a cross-sectional schematic view of an exemplary semiconductor device structure including a molybdenum nitride film deposited according to an embodiment of the present disclosure;

[0020] Figure 8 Shows a cross-sectional schematic view of another semiconductor device structure including a molybdenum nitride film according to an embodiment of the present disclosure;

[0021] Figure 9 Shows the effective work function of multiple gate stacks including molybdenum nitride films with various thicknesses deposited according to an embodiment of the present disclosure;

[0022] Figure 10 Shows the effective work function of other molybdenum nitride films with various thicknesses deposited according to an embodiment of the present disclosure;

[0023] Figure 11 Shows a schematic view of an exemplary semiconductor device structure including a molybdenum nitride film according to an embodiment of the present disclosure;

[0024] Figure 12 Shows another schematic view of an exemplary semiconductor device structure including a molybdenum nitride film according to an embodiment of the present disclosure; and

[0025] Figure 13 Shows a schematic view of a reaction system configured to deposit a molybdenum nitride film according to an embodiment of the present disclosure. Detailed Description

[0026] Although certain embodiments and examples are disclosed below, those skilled in the art will understand that the invention extends beyond the specifically disclosed embodiments and / or uses of the invention and obvious modifications and their equivalents. Accordingly, it is intended that the scope of the invention disclosed herein not be limited by the specific disclosed embodiments described below.

[0027] Furthermore, the illustrations presented herein are not meant to be actual views of any particular material, structure, or device, but are merely idealized representations used to describe embodiments of the present disclosure.

[0028] As used herein, the term "substrate" can refer to any one or more underlying materials on which a device, circuit, or film can be used or formed.

[0029] As used herein, the term "cyclic deposition" can refer to the sequential introduction of two or more precursors (reactants) into a reaction chamber to deposit a film over a substrate and includes deposition techniques such as atomic layer deposition (ALD) and cyclic chemical vapor deposition (cyclic CVD).

[0030] As used herein, the term "cyclic chemical vapor deposition" can refer to any process in which a substrate is sequentially exposed to two or more volatile precursors that react and / or decompose on the substrate to deposit a film.

[0031] As used herein, the term "atomic layer deposition" (ALD) can refer to a vapor deposition process that performs deposition cycles, preferably a plurality of consecutive deposition cycles, in a reaction chamber. Generally, during each unit deposition cycle, a precursor chemisorbs onto the deposition surface (e.g., the substrate surface or a previously deposited underlying surface, such as material from a previous ALD cycle), thereby forming a monolayer or sub-monolayer that is not readily reactive with additional precursors (i.e., a self-limiting reaction). Thereafter, if desired, a reactant (e.g., another precursor or reaction gas) can subsequently be introduced into the reaction chamber for converting the chemisorbed precursor into the desired material on the deposition surface. Generally, this reactant is capable of further reacting with the precursor. In addition, a purge step can also be utilized during each unit deposition cycle to remove excess precursor and / or remove excess reactant and / or reaction by-products from the reaction chamber after the chemisorbed precursor has been converted. Furthermore, when performed using alternating pulses of precursor compositions, reaction gases, and purge (e.g., inert carrier) gases, the term "atomic layer deposition" as used herein is also intended to include processes designated by related terms such as "chemical vapor atomic layer deposition", "atomic layer epitaxy (ALE)", molecular beam epitaxy (MBE), gas-source MBE or organometallic MBE, and chemical beam epitaxy.

[0032] As used herein, the term "film" can refer to any physically continuous or discontinuous structure and material formed by the methods disclosed herein. For example, a "film" can include 2D materials, nanolaminates, nanorods, nanotubes, or nanoparticles, or even partial or complete molecular layers, or partial or complete atomic layers, or clusters of atoms and / or molecules. A "film" can also include materials or layers having pinholes but still being at least partially physically continuous.

[0033] As used herein, the term "molybdenum nitride film" can refer to a film comprising at least one molybdenum component and a nitrogen component.

[0034] As used herein, the term "molybdenum halide precursor" can refer to a reactant comprising at least a molybdenum component and a halide component, wherein the halide component can include one or more of a chlorine component, an iodine component, or a bromine component.

[0035] As used herein, the term "chalcogenide molybdenum halide" can refer to a reactant comprising at least a molybdenum component, a halide component, and a chalcogen component, wherein the chalcogen is an element of Group IV of the periodic table, including oxygen (O), sulfur (S), selenium (Se), and tellurium (Te).

[0036] As used herein, the term "molybdenum oxyhalide" can refer to a reactant comprising at least a molybdenum component, an oxygen component, and a halide component.

[0037] As used herein, the term "reducing agent" can refer to a reactant that supplies electrons to another species in a redox chemical reaction.

[0038] As used herein, the term "crystalline film" can refer to a film that exhibits at least short-range order or even long-range order of a crystalline structure, and includes single-crystal films and polycrystalline films.

[0039] As used herein, the term "amorphous film" can refer to a film that essentially does not exhibit the order of a crystalline structure as observed in a crystalline film.

[0040] As used herein, the term "gas" can refer to a vapor or a vaporized solid and / or a vaporized liquid, and can be composed of a single gas or a gas mixture.

[0041] Embodiments of the present disclosure include methods that can be used to deposit molybdenum nitride films and related semiconductor device structures including molybdenum nitride films deposited according to embodiments of the present disclosure. In some embodiments of the present disclosure, the molybdenum nitride film can form part of a gate stack, such as at least a portion of a gate electrode to a transistor device structure. A gate electrode based on the molybdenum nitride film can provide a gate stack with a preferred effective work function for PMOS and NMOS devices.

[0042] The existing work function metals used for forming gate electrodes may have limitations due to their inappropriate effective work function values. For example, it is well known that the effective work function of a material can vary with its thickness. Therefore, as the device geometries in advanced technology nodes are reduced, the thicknesses of the corresponding device films, such as the work function metal of the gate electrode, also decrease in thickness, causing a change in the effective work function value of the total gate stack. This change in the effective work function of the gate stack may result in an effective work function that is non-ideal for NMOS and PMOS device structures.

[0043] In some embodiments of the present disclosure, the resistivity of the deposited molybdenum nitride film may be an important parameter in improving the performance of semiconductor devices, such as in applications where the molybdenum nitride film can be used as part of a gate electrode, a liner material (e.g., for memory applications), a barrier layer material, a capping material, or a contact layer. As discussed above, the next-generation technology nodes may require continuous reduction of the film thickness. However, as the film thickness of the conductive film decreases, the resistivity of the conductive film increases, resulting in an efficiency loss in the associated semiconductor device structure. As a non-limiting example, the molybdenum nitride film of the present disclosure can be used as an alternative to the common titanium nitride films currently used in semiconductor device structures. Therefore, the resistivity of the molybdenum nitride film of the present disclosure may be lower compared to the resistivity typically achieved in titanium nitride films of comparable thickness.

[0044] Accordingly, embodiments of the present disclosure may include a method of directly depositing a molybdenum nitride film on a substrate surface by a cyclic deposition process. The method may include: providing a substrate into a reaction chamber; and directly depositing the molybdenum nitride film on the substrate surface by performing one or more unit deposition cycles of the cyclic deposition process, wherein a unit deposition cycle includes: contacting the substrate with a first gaseous reactant comprising a molybdenum halide precursor; and contacting the substrate with a second gaseous reactant comprising a nitrogen precursor.

[0045] The method of directly depositing a molybdenum nitride film on a substrate surface disclosed herein may include a cyclic deposition process, such as atomic layer deposition (ALD) or cyclic chemical vapor deposition (cyclic CVD).

[0046] Non-limiting exemplary embodiments of a cyclic deposition process can include atomic layer deposition (ALD), where ALD is based on generally self-limiting reactions, whereby sequential and alternating pulses of reactants are used to deposit approximately one atomic (or molecular) monolayer of material per unit deposition cycle. Deposition conditions and precursors are typically selected to provide self-saturating reactions such that an adsorbed layer of one reactant leaves a surface termination that does not react with the gaseous reactant of the same reactant. Subsequently, the substrate is contacted with a different reactant that reacts with the previous termination to effect continued deposition. Thus, each cycle of alternating pulses typically leaves no more than approximately one monolayer of the desired material. However, as mentioned above, one of ordinary skill in the art will recognize that, for example, although the process has an alternating nature, more than one monolayer of material can be deposited in one or more ALD cycles if some gas-phase reactions occur.

[0047] In an exemplary ALD process for directly forming a molybdenum nitride film on a substrate surface, a unit deposition cycle can comprise: exposing the substrate to a first gaseous reactant, removing any unreacted first reactant and reaction by-products from the reaction chamber, and exposing the substrate to a second gaseous reactant, followed by a second removal step. In some embodiments of the present disclosure, the first gaseous reactant can comprise a molybdenum halide precursor, and the second gaseous reactant can comprise a nitrogen precursor.

[0048] The precursors can be separated by an inert gas such as argon (Ar) or nitrogen (N2) to prevent gas-phase reactions between the reactants and to effect self-saturating surface reactions. However, in some embodiments, the substrate can be moved to contact the first gaseous reactant and the second gaseous reactant separately. Because the reactions are self-saturating, strict temperature control of the substrate and precise dosing control of the precursors are generally not required. However, the substrate temperature is preferably such that incidental gas species neither condense into a monolayer nor decompose on the surface. Residual chemicals and reaction by-products (if any) are removed from the substrate surface before contacting the substrate with the next reactive chemical, such as by purging the reaction space or by moving the substrate. Undesired gaseous molecules can be effectively evacuated from the reaction space by means of an inert purge gas. A vacuum pump can be used to assist the purge.

[0049] A reactor capable of performing a cyclic deposition process can be used to deposit a molybdenum nitride film as described herein. Such reactors include ALD reactors and CVD reactors configured to provide precursors. According to some embodiments, a showerhead reactor can be used. According to some embodiments, a crossflow, batch, semi-batch, or spatial ALD reactor can be used.

[0050] In some embodiments of the present disclosure, a batch reactor may be used. In some embodiments, a vertical batch reactor may be used. For example, a vertical batch reactor may include a reaction chamber and a lift configured and arranged to move a boat, the boat being configured to support a batch of 10 to 200 substrates in or outside the reaction chamber. In other embodiments, the batch reactor includes a small batch reactor configured to accommodate 10 or fewer wafers, 8 or fewer wafers, 6 or fewer wafers, 4 or fewer wafers, or 2 or fewer wafers. In some embodiments using a batch reactor, the non-uniformity between wafers is less than 3% (1σ), less than 2%, less than 1%, or even less than 0.5%.

[0051] The exemplary cyclic deposition process described herein may optionally be carried out in a reactor and associated reaction chambers connected to a cluster tool. In a cluster tool, since each reaction chamber is dedicated to a particular process type, the temperature of the reaction chambers in each module can be kept constant, which will increase throughput compared to a reactor where the substrate is heated to the process temperature before each run. Additionally, in a cluster tool, the time required to pump the reaction chamber to the process pressure between substrates can be shortened. In some embodiments of the present disclosure, the exemplary cyclic deposition process for depositing a molybdenum nitride film disclosed herein may be carried out in a cluster tool comprising a plurality of reaction chambers, where each individual reaction chamber may be used to expose the substrate to a separate precursor gas and the substrate may be transferred between different reaction chambers to be exposed to multiple precursor gases, and the transfer of the substrate is carried out in a controlled environment to prevent substrate contamination. In some embodiments of the present disclosure, the cyclic deposition process described herein may be carried out in a cluster tool comprising a plurality of reaction chambers, where each individual reaction chamber may be configured to heat the substrate to a different temperature.

[0052] The standalone reactor may be equipped with a load lock. In this case, it is not necessary to cool the reaction chamber between each run.

[0053] According to some non-limiting embodiments of the present disclosure, an ALD process may be used to directly deposit a molybdenum nitride film on a substrate surface. In some embodiments of the present disclosure, each ALD unit deposition cycle may include two different deposition steps or stages. In the first stage of the unit deposition cycle ("molybdenum stage"), the surface of the substrate on which deposition is desired is contacted with a first gaseous reactant comprising a molybdenum precursor, which chemisorbs onto the substrate surface, thereby forming at most about one monolayer of reactant species on the substrate surface. In the second stage of the unit deposition cycle ("nitrogen stage"), the surface of the substrate on which deposition is desired is contacted with a second gaseous reactant comprising a nitrogen precursor.

[0054] It may be referred to Figure 1Understand an exemplary cyclic deposition process for depositing a molybdenum nitride film directly on a substrate surface. The figure shows an exemplary atomic layer deposition process 100 for depositing a molybdenum nitride film on a substrate surface.

[0055] More specifically, Figure 1 An exemplary molybdenum nitride deposition process 100 including a cyclic deposition stage 105 is shown. The exemplary atomic layer deposition process 100 can start from process block 110, which includes providing a substrate into a reaction chamber and heating the substrate to a desired deposition temperature.

[0056] In some embodiments of the present disclosure, the substrate can include a planar substrate or a patterned substrate including high aspect ratio features such as vertical trenches, horizontal trenches, vertical gap features, horizontal gap features, and / or fin structures. The substrate can include one or more materials, including but not limited to semiconductor materials, dielectric materials, and metal materials. The substrate can also include one or more exposed surfaces, including (but not limited to) semiconductor surfaces, dielectric surfaces, and metal surfaces.

[0057] In some embodiments, the substrate can include a semiconductor material such as, but not limited to, silicon (Si), germanium (Ge), germanium tin (GeSn), silicon germanium (SiGe), silicon germanium tin (SiGeSn), silicon carbide (SiC), or III-V semiconductor materials.

[0058] In some embodiments, the substrate can include a dielectric material such as, but not limited to, silicon-containing dielectric materials and metal oxide dielectric materials. In some embodiments, the substrate can include one or more silicon-containing dielectric materials / surfaces such as, but not limited to, silicon dioxide (SiO2), sub-oxide silicon, silicon nitride (Si3N4), silicon oxynitride (SiON), silicon oxycarbide (SiOC), silicon oxycarbonitride (SiOCN), and silicon carbonitride (SiCN). In some embodiments, the substrate can include one or more metal oxide materials / surfaces such as, but not limited to, aluminum oxide (Al2O3), hafnium oxide (HfO2), tantalum oxide (Ta2O5), zirconium oxide (ZrO2), titanium oxide (TiO2), hafnium silicate (HfSiO x ) and lanthanum oxide (La2O3).

[0059] In some embodiments, the substrate can include an engineered substrate where a surface semiconductor layer is disposed above a body support member with an intervening buried oxide (BOX) therebetween.

[0060] The patterned substrate can include a substrate that can include semiconductor device structures formed into or on the surface of the substrate. For example, the semiconductor device structures can include partially fabricated semiconductor device structures such as transistors and memory elements. In some embodiments, the substrate can have a single crystal surface and / or one or more subsurfaces that can include non-single crystal surfaces such as polycrystalline surfaces and / or amorphous surfaces.

[0061] The reaction chamber for deposition can be an atomic layer deposition reaction chamber or a chemical vapor deposition reaction chamber or any of the reaction chambers described previously herein.

[0062] In some embodiments of process block 110( Figure 1 ), the substrate can be heated to the deposition temperature of the subsequent cyclic deposition stage 105. For example, the substrate can be heated to a substrate temperature below about 700 °C, or below about 600 °C, or below about 500 °C, or below about 400 °C, or below about 300 °C, or even below about 200 °C. In some embodiments, the substrate temperature during the cyclic deposition process 100 can be between about 200 °C and 700 °C, or between about 350 °C and 600 °C, or between about 450 °C and 550 °C.

[0063] In addition to achieving the desired deposition temperature (i.e., the desired substrate temperature), the exemplary cyclic deposition process 100 can also adjust the pressure within the reaction chamber during film deposition. For example, in some embodiments, the exemplary cyclic deposition process 100 can be carried out in a reaction chamber that is adjusted to a pressure less than 300 Torr, or less than 200 Torr, or less than 100 Torr, or less than 50 Torr, or less than 30 Torr, or less than 10 Torr, or less than 5 Torr, or even less than 2 Torr. In some embodiments, the pressure within the reaction chamber during deposition can be adjusted at a pressure between about 2 Torr and 300 Torr, or between 30 Torr and 80 Torr.

[0064] After heating the substrate to the desired deposition temperature and adjusting the pressure within the reaction chamber, the exemplary cyclic deposition process 100 (e.g., an ALD process) can continue with cyclic deposition stage 105 via process block 120, which includes contacting the substrate with a first gaseous reactant that includes a molybdenum halide precursor, i.e., a molybdenum precursor.

[0065] In some embodiments of the present disclosure, the molybdenum halide precursor can include a molybdenum chloride precursor, a molybdenum bromide precursor, or a molybdenum iodide precursor. For example, as non-limiting examples, molybdenum chloride can include one or more of the following: molybdenum pentachloride (MoCl5) or molybdenum hexachloride (MoCl6).

[0066] In some embodiments, the molybdenum halide precursor may include a chalcogenide molybdenum halide precursor, such as a molybdenum oxyhalide precursor selected from the group consisting of molybdenum oxychloride, molybdenum oxyiodide, and / or molybdenum oxybromide. In some embodiments, the molybdenum precursor may include molybdenum oxychloride, including one of the following: molybdenum(V) oxychloride (MoOCl3), molybdenum(VI) oxychloride (MoOCl4), or molybdenum(IV) dioxydichloride (MoO2Cl2).

[0067] In alternative embodiments, the first gaseous reactant, i.e., the molybdenum precursor, may include a metal-organic molybdenum precursor, such as Mo(NMe2)4, Mo(NEt2)4, Mo2(NMe2)6, Mo(tBuN)2(NMe2)2, Mo(tBuN)2(NEt2)2, Mo(NEtMe)4, Mo(NtBu)2(StBu)2, Mo(NtBu)2(iPr2AMD)2Mo(thd)3, MoO2(acac), MoO2(thd)2, and / or MoO2(iPr2AMD)2. The first gaseous reactant may include an organometallic molybdenum compound, including but not limited to compounds containing cyclopentadienyl (Cp) ligands, η 6 -arene ligands, and carbonyl ligands, such as Mo(CO)6, Mo(Cp)2H2, Mo(iPrCp)2H2, Mo(η 6 -ethylbenzene)2, MoCp(CO)2(η 3 -allyl), MoCp(CO)2(NO), Mo(benzene)2, MoCp2Cl2, and MoCp(NMe)3, and variants thereof.

[0068] In at least one embodiment of the present invention, the first gaseous reactant may include bis(tert-butylimino)bis(dimethylamino)molybdenum(VI). The first gaseous reactant may react with a second gaseous reactant, where the second gaseous reactant may include ammonia. The resulting molybdenum nitride film may have a work function value, resistivity, and flatband shift suitable for pMOS work function metal applications. This may be partly attributed to, for example, the relatively high electronegativity of molybdenum compared to titanium or vanadium. Additionally, the lower resistivity of molybdenum nitride enables a higher effective work function.

[0069] In some embodiments of the present disclosure, contacting the substrate with the molybdenum halide precursor may include a time period between about 0.1 second and about 60 seconds, between about 0.1 second and about 10 seconds, or even between about 0.5 second and about 5.0 seconds. Additionally, during the contacting of the substrate with the molybdenum halide precursor, the flow rate of the molybdenum halide precursor may be less than 1000 sccm, or less than 500 sccm, or less than 100 sccm, or less than 10 sccm, or even less than 1 sccm. Additionally, during the contacting of the substrate with the molybdenum halide precursor, the flow rate of the molybdenum precursor may be in the range of about 1 to 2000 sccm, about 5 to 1000 sccm, or about 10 to about 500 sccm.

[0070] As schematized by Figure 1 The exemplary cyclic deposition process for depositing a molybdenum nitride film, as schematized by process 100, may continue by purging the reaction chamber. For example, the excess molybdenum halide precursor and reaction by-products (if any) may be removed from the substrate surface, for example, by pumping with an inert gas. In some embodiments of the present disclosure, the purge process may include a purge cycle in which the substrate surface is purged for a period of less than about 5 seconds, or less than about 3 seconds, or less than about 2 seconds, a period between about 2 seconds and 5 seconds. The excess molybdenum halide precursor and any possible reaction by-products may be removed by means of a vacuum generated by a pumping system in fluid communication with the reaction chamber. In some embodiments of the present disclosure, the purge cycle after contacting the substrate with the first gaseous reactant may be omitted.

[0071] The exemplary cyclic deposition process 100 may continue with a second stage of the cyclic deposition stage 105 by means of process block 130, which includes contacting the substrate with a second gaseous reactant, particularly contacting the substrate with a second gaseous reactant comprising a nitrogen precursor ("nitrogen stage").

[0072] In some embodiments of the present disclosure, the nitrogen precursor may include at least one of the following: molecular nitrogen (N2), ammonia (NH3), hydrazine (N2H4), hydrazine derivatives, or nitrogen-based plasmas. In some embodiments, the hydrazine derivatives may include alkyl-hydrazines, including at least one of the following: tert-butyl hydrazine (C4H9N2H3), methyl hydrazine (CH3NHNH2), 1,1-dimethyl hydrazine ((CH3)2N2H2), 1,2-dimethyl hydrazine, ethyl hydrazine, 1,1-diethyl hydrazine, 1-ethyl-1-methyl hydrazine, isopropyl hydrazine, phenyl hydrazine, 1,1-diphenyl hydrazine, 1,2-diphenyl hydrazine, N-aminopiperidine, N-aminopyrrole, N-aminopyrrolidine, N-methyl-N-phenyl hydrazine, 1-amino-1,2,3,4-tetrahydroquinoline, N-aminopiperazine, 1,1-dibenzyl hydrazine, 1,2-dibenzyl hydrazine, 1-ethyl-1-phenyl hydrazine, 1-aminoazepane, 1-methyl-1-(m-tolyl) hydrazine, 1-ethyl-1-(p-tolyl) hydrazine, 1-aminoimidazole, 1-amino-2,6-dimethylpiperidine, N-aminoaziridine, or azo-tert-butane. In some embodiments, the nitrogen-based plasma can be generated by applying RF power to a nitrogen-containing gas, and the nitrogen-based plasma may include atomic nitrogen (N), nitrogen ions, nitrogen radicals, and excited nitrogen species. In some embodiments, the nitrogen-based plasma may further include additional reactive species, such as by adding an additional gas.

[0073] In some embodiments of the present disclosure, contacting the substrate with the nitrogen precursor may include a contact time period between about 0.01 seconds and about 180 seconds, or between about 0.05 seconds and about 60 seconds, or even between about 0.1 seconds and about 10.0 seconds. In some embodiments, the substrate may be exposed to the nitrogen precursor for a time period less than 60 seconds, or less than 30 seconds, or less than 15 seconds, or even less than 5 seconds. In some embodiments, the substrate may be exposed to the nitrogen precursor for a time period between 5 seconds and 60 seconds, or between 5 seconds and 30 seconds. Additionally, during the process of contacting the substrate with the nitrogen precursor, the flow rate of the nitrogen precursor may be lower than 30 slm, or lower than 15 slm, or lower than 10 slm, or lower than 5 slm, or lower than 2 slm, or even lower than 1 slm. Additionally, during the process of contacting the substrate with the nitrogen precursor, the flow rate of the nitrogen precursor may be in the range of about 0.1 to 30 slm, about 2 to 15 slm, or equal to or greater than 2 slm.

[0074] After contacting the substrate with the nitrogen precursor, the exemplary cyclic deposition process 100 may be carried out by purging the reaction chamber, as described previously herein. In some embodiments of the present disclosure, the purge cycle after contacting the substrate with the nitrogen precursor may be omitted.

[0075] The cyclic deposition stage 105 of the exemplary cyclic deposition process 100 can proceed to decision gate 140, where decision gate 140 depends on the average film thickness of the molybdenum nitride film being deposited. For example, if the deposited molybdenum nitride film is not thick enough for the desired device application, the cyclic deposition stage 105 can be repeated by returning to process block 120 and continuing with further unit deposition cycles, where the unit deposition cycle can include contacting the substrate with a molybdenum halide precursor (process block 120), purging the reaction chamber, contacting the substrate with a nitrogen precursor (process block 130), and purging the reaction chamber again. In some embodiments, the purge cycle can be omitted after introducing the precursor in the unit deposition cycle of the cyclic deposition stage 105.

[0076] The unit deposition cycle of the cyclic deposition stage 105 can be repeated one or more times until a molybdenum nitride film of the desired average film thickness is deposited on the substrate. Once the molybdenum nitride film has been deposited to the desired average film thickness, the exemplary cyclic deposition process 100 can exit via process block 150, and the substrate with the molybdenum nitride film deposited thereon can be subjected to further processing to form, for example, a semiconductor device structure.

[0077] It should be understood that in some embodiments of the present disclosure, the order of contacting the substrate with a first gaseous reactant (e.g., a molybdenum precursor) and a second gaseous reactant (e.g., a nitrogen precursor) can be such that the substrate is first contacted with the second gaseous reactant and then with the first gaseous reactant. Additionally, in some embodiments, the cyclic deposition stage 105 of the exemplary cyclic deposition process 100 can include contacting the substrate with the first gaseous reactant one or more times and then contacting the substrate with the second gaseous reactant one or more times. Additionally, in some embodiments, the cyclic deposition stage 105 of the exemplary cyclic deposition process 100 can include contacting the substrate with the second gaseous reactant one or more times and then contacting the substrate with the first gaseous reactant one or more times.

[0078] In some embodiments, the cyclic deposition process as described herein can include a hybrid ALD / CVD or cyclic CVD process. For example, in some embodiments, the growth rate of an ALD process may be lower compared to a CVD process. One way to increase the growth rate can be to operate at a higher substrate temperature compared to the temperature typically employed in an ALD process, resulting in a part of a chemical vapor deposition process but still utilizing the sequential introduction of precursors, and such a process can be referred to as cyclic CVD. In some embodiments, the cyclic CVD process can include introducing two or more precursors into the reaction chamber, where there may be an overlapping time period between the two or more precursors in the reaction chamber, thereby resulting in an ALD deposition component and a CVD deposition component. For example, the cyclic CVD process can include a first precursor flowing continuously into the reaction chamber and a second precursor being pulsed periodically into the reaction chamber.

[0079] In some embodiments, a cyclic deposition process for depositing a molybdenum nitride film can include unit deposition, and the unit deposition further includes contacting a substrate with a third gaseous reactant comprising a reducing agent. As a non-limiting example, in some embodiments, the nitrogen precursor and the reducing agent can be co-fed into the reaction chamber, i.e., the substrate is contacted with the nitrogen precursor and the reducing agent simultaneously. As another non-limiting example, in some embodiments, the nitrogen precursor and the reducing agent can be introduced into the reaction chamber as separate gas pulses, for example, a purge cycle can be performed between the processes of contacting the substrate with the nitrogen precursor and contacting the substrate with the reducing agent.

[0080] More specifically, Figure 2 An exemplary cyclic deposition process 200 for molybdenum nitride deposition is shown. The exemplary process 200 can include a cyclic deposition stage 205, which includes a process block 230, where the substrate is contacted with a gas comprising a nitrogen precursor and a reducing agent precursor, i.e., the nitrogen precursor and the reducing agent precursor are simultaneously exposed to the substrate.

[0081] The exemplary cyclic deposition process 200 can start from a process block 210, which includes providing the substrate into the reaction chamber and heating the substrate to a desired deposition temperature. The process block 210 can be substantially the same as Figure 1 the process block 110, and thus, for the sake of brevity, the description of the process block 210 is not repeated.

[0082] The exemplary cyclic deposition process 200 can continue with the cyclic deposition stage 205 starting with a process block 220, which includes contacting the substrate with a molybdenum halide precursor. The process block 220 can be substantially the same as Figure 1 the process block 120, and thus, for the sake of brevity, the description of the process block 220 is not repeated.

[0083] The exemplary cyclic deposition process 200 ( Figure 2 ) can continue by purging the reaction chamber as previously discussed with respect to Figure 1 the exemplary process 100. In some embodiments of the present disclosure, the purge cycle after contacting the substrate with the molybdenum halide precursor can be omitted.

[0084] The exemplary cyclic deposition process 200 can continue with a second stage of the cyclic deposition stage 205 by means of a process block 230, which includes contacting the substrate with a gas comprising a nitrogen precursor and a reducing agent. In other words, the substrate can be contacted with a gas comprising both a nitrogen precursor and a reducing agent. In at least one embodiment of the present invention, the single gas contacting the substrate can be the nitrogen precursor and the reducing agent.

[0085] In some embodiments, the nitrogen precursor can include as previously discussed with respect to Figure 1One or more of the nitrogen precursors described in process block 130, and thus, for the sake of brevity, the nitrogen precursors that can be employed in exemplary process 200 are not described further.

[0086] In some embodiments of the present disclosure, the substrate can be contacted with a gas comprising a nitrogen precursor and a reducing agent for a period of time between about 0.01 seconds and about 180 seconds, between about 0.05 seconds and about 60 seconds, or between about 0.1 seconds and about 10.0 seconds, or for a period of time less than 60 seconds, or less than 30 seconds, or less than 15 seconds, or even less than 5 seconds. In some embodiments, the substrate can be exposed to the gas comprising the nitrogen precursor and the reducing agent for a period of time between about 5 seconds and 60 seconds or between about 5 seconds and 30 seconds. Additionally, during the process of contacting the substrate with the gas comprising both the nitrogen precursor and the reducing agent, the flow rate of the nitrogen precursor can be less than 30 slm, or less than 15 slm, or less than 10 slm, or less than 5 slm, or less than 2 slm, or less than 1 slm, or even between about 1 slm and 30 slm. Additionally, the flow rate of the reducing agent can be less than 30 slm, or less than 15 slm, or less than 10 slm, or less than 5 slm, or less than 2 slm, or even between about 2 slm and 30 slm.

[0087] As previously described herein, the exemplary cyclic deposition process 200 can continue with purging the reaction chamber. In some embodiments of the present disclosure, the purge cycle after contacting the substrate with the nitrogen precursor / reducing agent can be omitted.

[0088] The cyclic deposition stage 205 of the exemplary cyclic deposition process 200 can continue to decision gate 240, where decision gate 240 depends on the average film thickness of the molybdenum nitride film deposited. For example, if the average film thickness of the deposited molybdenum nitride film is not sufficient for the desired device application, the cyclic deposition stage 205 can be repeated by returning to process block 220 and continuing further unit deposition cycles, where the unit deposition cycle can include contacting the substrate with the molybdenum halide precursor (process block 220), purging the reaction chamber, contacting the substrate with the gas comprising the nitrogen precursor and the reducing agent (process block 230), and purging the reaction chamber again. In some embodiments, the purge cycle can be omitted after introducing the precursor for the unit deposition cycle of the cyclic deposition stage 205.

[0089] The unit deposition cycle of the cyclic deposition stage 205 can be repeated one or more times until a molybdenum nitride film of a desired average film thickness is deposited on the substrate. Once the molybdenum nitride film has been deposited to the desired average film thickness, the exemplary cyclic deposition process 200 can exit via process block 250, and the substrate with the molybdenum nitride film deposited thereon can be subjected to further processing to form, for example, a device structure.

[0090] It should be understood that in some embodiments of the present disclosure, the order of contact between the substrate and the molybdenum halide precursor and the gas containing the nitrogen precursor and the reducing agent can be such that the substrate is first contacted with the gas containing the nitrogen precursor and the reducing agent, and then with the molybdenum halide precursor. Additionally, in some embodiments, the cyclic deposition stage 205 of the exemplary process 200 can include contacting the substrate with the molybdenum halide precursor one or more times, and then contacting the substrate with the gas containing the nitrogen precursor and the reducing agent one or more times. Additionally, in some embodiments, the cyclic deposition stage 205 of the exemplary process 200 can include contacting the substrate with the gas containing the nitrogen precursor and the reducing agent one or more times, and then contacting the substrate with the molybdenum halide precursor one or more times.

[0091] In some embodiments, an exemplary cyclic deposition process for depositing a molybdenum nitride film can include separate pulses of the nitrogen precursor and the reducing agent. For example, a purge cycle can be performed between contacting the substrate with the nitrogen precursor and contacting the substrate with the reducing agent.

[0092] More specifically, Figure 3 An exemplary cyclic deposition process 300 including a cyclic deposition stage 305 is shown. In some embodiments, the cyclic deposition stage 305 can include a process block 330 for contacting the substrate with the nitrogen precursor and a process block 340 for contacting the substrate with the reducing agent, i.e., the substrate can be separately exposed to the nitrogen precursor and the reducing agent.

[0093] The exemplary cyclic deposition process 300 can start from a process block 310, which includes providing the substrate into the reaction chamber and heating the substrate to a desired deposition temperature. The process block 310 can be substantially the same as Figure 1 the process block 110, and thus, for the sake of brevity, the description of the process block 310 is not repeated.

[0094] The exemplary cyclic deposition process 300 can continue with a cyclic deposition stage 305 starting with a process block 320 that includes contacting the substrate with the molybdenum halide precursor. The process block 320 can be substantially the same as Figure 1 the process block 120, and thus, for the sake of brevity, the description of the process block 220 is not repeated.

[0095] The exemplary cyclic deposition stage 305 of the exemplary cyclic deposition process 300 ( Figure 3 ) can continue by purging the reaction chamber as previously discussed with respect to Figure 1 the exemplary process 100. In some embodiments of the present disclosure, the purge cycle after contacting the substrate with the molybdenum halide precursor can be omitted.

[0096] The exemplary cyclic deposition process 300 ( Figure 3) can be continued with a second stage of the cyclic deposition stage 305 by means of process frame 330, which includes bringing the substrate into contact with a nitrogen precursor. Process frame 330 can be substantially the same as the process frame 130 of Figure 1 , and thus, for the sake of brevity, the description of process frame 330 will not be repeated.

[0097] The exemplary cyclic deposition stage 300 of process 300 ( Figure 3 ) can be continued by purging the reaction chamber as previously discussed with respect to the exemplary process 100 of Figure 1 . In some embodiments of the present disclosure, the purge cycle after bringing the substrate into contact with the nitrogen precursor can be omitted.

[0098] The exemplary cyclic deposition process 300 can be continued with a third stage of the cyclic deposition stage 305 by means of process frame 340, which includes bringing the substrate into contact with a reducing agent. In some embodiments of the present disclosure, the reducing agent precursor can be selected from those reducing agent precursors previously described with respect to process frame 230, and thus, for the sake of brevity, the reducing agent used in process 220 will not be repeated.

[0099] In some embodiments of the present disclosure, the substrate can be in contact with the reducing agent for a period of time between about 0.01 seconds and about 180 seconds, between about 0.05 seconds and about 60 seconds, or between about 0.1 seconds and about 10.0 seconds, or for a period of time less than 60 seconds, or less than 30 seconds, or less than 15 seconds, or even less than 5 seconds. In some embodiments, the substrate can be exposed to the reducing agent precursor for a period of time between 5 seconds and 60 seconds or between 5 seconds and 30 seconds. Additionally, during the process of bringing the substrate into contact with the reducing agent, the flow rate of the reducing agent precursor can be less than 100 slm, or less than 50 slm, or less than 25 slm, or less than 10 slm, or less than 5 slm, or even between approximately 5 slm and 100 slm.

[0100] The exemplary cyclic deposition process 300 ( Figure 3 ) can be continued by purging the reaction chamber as previously discussed with respect to the exemplary process 100 of Figure 1 . In some embodiments of the present disclosure, the purge cycle after bringing the substrate into contact with the reducing agent can be omitted.

[0101] The cyclic deposition stage 305 of the exemplary process 300 ( Figure 3)Decision gate 350 can be continued, where decision gate 350 depends on the average film thickness of the deposited molybdenum nitride film. For example, if the average film thickness of the deposited molybdenum nitride film is insufficient for the desired device application, the cyclic deposition stage 305 can be repeated by returning to process block 320 and continuing with further unit deposition cycles, where the unit deposition cycle can include contacting the substrate with a molybdenum halide precursor (process block 320), purging the reaction chamber, contacting the substrate with a nitrogen precursor (process block 330), purging the reaction chamber, contacting the substrate with a reducing agent (process block 340), and purging the reaction chamber again. In some embodiments, the purging cycle can be omitted after introducing the precursor in the unit deposition cycle of the cyclic deposition stage 305.

[0102] The unit deposition cycles of the cyclic deposition stage 305 can be repeated one or more times until a molybdenum nitride film with a desired average film thickness is deposited on the substrate. Once the molybdenum nitride film has been deposited to the desired average film thickness, the exemplary cyclic deposition process 300 can exit via process block 360, and the substrate with the molybdenum nitride film deposited thereon can be subjected to further processing to form, for example, a device structure.

[0103] It should be understood that in some embodiments of the present disclosure, the order of contacting the substrate with the molybdenum halide precursor, the nitrogen precursor, and the reducing agent can be in any conceivable sequential order and is not limited by the Figure 3 sequence order shown therein. Additionally, the contact of the substrate with a particular precursor, such as the molybdenum halide precursor, the nitrogen precursor, or the reducing agent, can be repeated one or more times before performing subsequent process blocks of the cyclic deposition stage 305.

[0104] The exemplary deposition process disclosed herein can deposit a molybdenum nitride film directly on the substrate surface at a growth rate of about cycles to about cycles, about cycles to about cycles, or even about cycles to about cycles. In some embodiments, the growth rate of the molybdenum nitride film directly on the substrate surface exceeds about cycles, exceeds about cycles, or even exceeds about cycles. In some embodiments of the present disclosure, it can be between cycles and cycles or between cycles and cycles, or at a deposition temperature, i.e., the substrate temperature, between 300 °C and 700 °C, or between 400 °C and 500 °C, or even less than 450 °C, deposit the molybdenum nitride film.

[0105] The molybdenum nitride film deposited by the method disclosed herein can be a physically continuous film. In some embodiments, the molybdenum nitride film can be physically continuous at an average film thickness below about or below about or below about or below about or below about or about even between about and The average film thickness can be physically continuous.

[0106] In some embodiments, the average film thickness at which the film can be made physically continuous can be different from the average film thickness at which the film can be made electrically continuous, and vice versa.

[0107] In some embodiments, the molybdenum nitride film deposited according to the method disclosed herein is below or below or below or below or even between about to The average film thickness can be physically continuous. In other words, the molybdenum nitride film can have a thickness less than or less than or less than less than or even between about and The average film closing thickness. The thickness at which the film becomes physically continuous can be determined using low energy ion scattering (LEIS).

[0108] In some embodiments, the molybdenum nitride film of the present disclosure can have about to or about to or even about to The average film thickness. In some embodiments, the molybdenum nitride film of the present disclosure can have a thickness greater than about or greater than about or greater than about or greater than about or greater than about or greater than about or greater than about or greater than about or even between about and The average film thickness. In some embodiments, the molybdenum nitride film of the present disclosure can have a thickness less than about or less than about or less than about or less than about or less than about or less than about or even about and average film thickness.

[0109] In some embodiments, molybdenum nitride films deposited according to the methods disclosed herein may comprise low resistivity molybdenum nitride films. More particularly, Figure 4 shows the resistivity of a plurality of molybdenum nitride films of various thicknesses deposited according to embodiments of the present disclosure, where the data labeled 400 comprises molybdenum nitride films deposited by cyclic deposition process 100( Figure 1 ), the data labeled 410 comprises molybdenum nitride films deposited by cyclic deposition process 200( Figure 2 ), and the data labeled 420 comprises molybdenum nitride films deposited by cyclic deposition process 300( Figure 3 ). Figure 4 Examination of the resistivity data clearly illustrates that the addition of a reducing agent in process 200 (data labeled 410) and process 300 (data labeled 420) reduces the resistivity of the molybdenum nitride film. Additionally, Figure 4 further examination clearly illustrates that the resistivity of the deposited molybdenum nitride film is further reduced by separately introducing pulses of the nitrogen precursor and the reducing agent (process 300 / data labeled 420) compared to molybdenum nitride films deposited using a co-flow of the nitrogen precursor and the reducing agent (process 200 / data labeled 410).

[0110] As a non-limiting example, molybdenum nitride films deposited according to embodiments of the present disclosure may have a resistivity of less than 750 μΩ-cm at an average film thickness of less than , or may have a resistivity of less than 750 μΩ-cm at an average film thickness of less than , or may have a resistivity of less than 1300 μΩ-cm at an average film thickness of less than .

[0111] As another non-limiting example, molybdenum nitride films deposited according to embodiments of the present disclosure may have a resistivity of less than 550 μΩ-cm at an average film thickness of less than , or may have a resistivity of less than 550 μΩ-cm at an average film thickness of less than , or may have a resistivity of less than 950 μΩ-cm at an average film thickness of less than .

[0112] As another non-limiting example, molybdenum nitride films deposited according to embodiments of the present disclosure may have a resistivity of less than The resistivity can be less than 250 μΩ-cm at an average film thickness of, or less than The resistivity can be less than 250 μΩ-cm at an average film thickness of, or less than The resistivity can be less than 600 μΩ-cm at an average film thickness of.

[0113] In some embodiments, for molybdenum nitride films having an average film thickness between approximately and or approximately and or even between approximately and the molybdenum nitride films deposited according to embodiments of the present disclosure can have a resistivity between 250 μΩ-cm and 1000 μΩ-cm, or between 250 μΩ-cm and 750 μΩ-cm, or even between 250 μΩ-cm and 500 μΩ-cm.

[0114] The excellent resistivity of the molybdenum nitride films deposited by embodiments of the present disclosure is further shown in Figure 5 which shows the resistivity of a plurality of molybdenum nitride films of various thicknesses deposited on a dielectric substrate according to embodiments of the present disclosure. Additionally, Figure 5 the resistivity of the molybdenum films of the present disclosure is also compared with that of prior art titanium nitride films of varying thicknesses deposited using titanium tetrachloride precursor. The data labeled 500 corresponds to a titanium nitride film deposited using titanium tetrachloride (TiCl4). Figure 5 All of the films shown in

[0115] are deposited on the exposed surface of a dielectric material. Figure 5 More specifically, the data labeled 510 corresponds to a molybdenum nitride film deposited on a silicon oxide substrate, and the data labeled 520 corresponds to a molybdenum nitride film deposited on a hafnium oxide (HfO2) substrate.

[0116] Figure 5 Examination of the resistivity data in

[0117] clearly shows that when compared to the resistivity of prior art titanium nitride films of comparable thickness, the molybdenum nitride films of the present disclosure have a reduced resistivity at a reduced average film thickness.

[0117] As a non-limiting example, the molybdenum nitride films of the present disclosure can have a resistivity less than 250 μΩ-cm at an average film thickness of less than or less than can have a resistivity of less than 300 μΩ-cm at an average film thickness of, or less than can have a resistivity of less than 400 μΩ-cm at an average film thickness of. In some embodiments, the molybdenum nitride films of the present disclosure can have a resistivity between about 250 μΩ-cm and 400 μΩ-cm at an average film thickness of less than .

[0118] In some embodiments, molybdenum nitride films deposited according to the embodiments disclosed herein can include crystalline films or amorphous films. In certain embodiments where the molybdenum nitride film is crystalline, the molybdenum nitride film can include a MoN phase or a Mo2N phase. In some embodiments, the molybdenum nitride film can include both a MoN phase and a Mo2N phase.

[0119] More specifically, Figure 6 shows x-ray diffraction (XRD) data obtained from an exemplary molybdenum nitride film deposited according to the embodiments of the present disclosure, where the XRD data labeled 600 includes a molybdenum nitride film deposited by a cyclic deposition process 100 ( Figure 1 ), the XRD data labeled 610 includes a molybdenum nitride film deposited by a cyclic deposition process 200 ( Figure 2 ), and the data labeled 620 includes a molybdenum nitride film deposited by a cyclic deposition process 300 ( Figure 3 ). Figure 6 Examination of the XRD data of shows no significant differences between the XRD data of the molybdenum nitride films deposited by processes 100, 200, or 300. However, Figure 6 further examination of the XRD data of shows four main peaks in the XRD data labeled 630, 640, 650, and 660. The XRD peak labeled 630 corresponds to a MoN phase with a (200) crystalline orientation and a Mo2N(200) with a (111) crystalline orientation. The XRD peak labeled 640 corresponds to a Mo2N phase with a (200) crystalline orientation. The XRD peak labeled 650 corresponds to a MoN phase with a (220) crystalline orientation and a Mo2N phase with a (200) crystalline orientation. The XRD peak labeled 660 corresponds to a MoN phase with a (222) crystalline orientation and a Mo2N phase with a (311) crystalline orientation.

[0120] In embodiments where the composition of the deposited molybdenum nitride film includes at least a MoN phase and a Mo2N phase, the ratio (MoN:Mo2) of the MoN phase present in the molybdenum nitride film to the Mo2N phase present in the molybdenum nitride film can be controlled during the cyclic deposition process of the present disclosure. For example, the MoN:Mo2N ratio can be varied by changing the cyclic deposition parameters of the molybdenum nitride deposition, which include (but are not limited to) deposition temperature, reaction chamber pressure, precursor concentration, or addition of other gas species.

[0121] In some embodiments, the MoN phase of molybdenum nitride can be superior to the Mo2N phase of molybdenum nitride, i.e., the MoN:Mo2N ratio increases. As a non-limiting example, the MoN phase can be preferentially deposited relative to the Mo2N phase by adding a reducing agent to the deposition process.

[0122] The exemplary cyclic deposition method disclosed herein can also deposit molybdenum nitride films having improved average r.m.s. surface roughness. For example, in some embodiments, the molybdenum nitride film can have an average r.m.s. surface roughness (R a )(as-deposited) of less than 0.30 nm, or less than 0.25 nm, or less than 0.20 nm, or less than 0.10 nm, or even between 0.10 nm and 0.30 nm. The average r.m.s. surface roughness (R a ) of the as-deposited molybdenum nitride film can be determined using an atomic force microscope (AFM) by scanning, for example, an area of approximately 100 μm × 100 μm.

[0123] In some embodiments, the surface roughness of the molybdenum nitride film can be expressed as a percentage of roughness of the average total thickness of the molybdenum nitride film. For example, the surface roughness percentage of the molybdenum nitride film of the present disclosure can be less than 10%, or less than 5%, or less than 3%, or less than 2%, or less than 1.5%, or even less than 1%. As a non-limiting example, the molybdenum nitride film deposited according to the embodiments of the present disclosure can have an average film thickness of approximately wherein the molybdenum nitride film has an r.m.s. surface roughness (R ) of less than a and a corresponding surface roughness percentage of less than 4%.

[0124] In some embodiments, the substrate can include at least one of a dielectric surface, a semiconductor surface, or a metal surface. As used herein, the term "dielectric surface" can refer to the surface of a dielectric material, including (but not limited to) for example silicon-containing dielectric materials such as silicon oxide, silicon nitride, silicon oxynitride, silicon carbonitride, and mixtures thereof, as well as metal oxides. As used herein, the term "metal surface" can refer to a surface including a metal component, including but not limited to a metal surface, a metal oxide surface, a metal silicide surface, a metal nitride surface, and a metal carbide surface. In some embodiments, the substrate can include both a dielectric surface and a metal surface, and the cyclic deposition process of the present disclosure can be used to deposit a molybdenum nitride film directly on both the dielectric surface and the metal surface, i.e., without using an intermediate nucleation layer.

[0125] Molybdenum nitride films deposited according to embodiments of the present disclosure can be used in a variety of applications. For example, the molybdenum nitride film can be used as a barrier layer material to prevent the diffusion of metal species into the interlayer dielectric, or as a liner material, or as part of a gate stack formed on a semiconductor device structure.

[0126] As a non-limiting example embodiment, the molybdenum nitride film deposited according to embodiments of the present disclosure can be used as a barrier layer in back-end-of-line (BEOL) metallization applications, such as Figure 7 shown in. More specifically, Figure 7 illustrates a partially fabricated semiconductor device structure 700, which includes a substrate 702 that can include partially fabricated and / or fabricated semiconductor device structures, such as transistors and memory elements (not shown). The partially fabricated semiconductor device structure 700 can include a dielectric material 704 formed over the substrate 702, and the dielectric material can include a low dielectric constant material, i.e., a low-k dielectric, such as a silicon-containing dielectric or a metal oxide dielectric. Trenches can be formed in the dielectric material 704, and a barrier layer 706 can be disposed on the surface of the trenches, which prevents or substantially prevents the metal interconnect material 708 from diffusing into the surrounding dielectric material 704. In some embodiments of the present disclosure, the barrier layer 706 can include a molybdenum nitride film deposited by the deposition processes described herein.

[0127] The partially fabricated semiconductor structure 700 can also include a metal interconnect material 708 for electrically interconnecting a plurality of device structures disposed in / on the substrate 702. In some embodiments, the metal interconnect material 708 can include copper or cobalt. Additionally, a capping layer 710 can be disposed on the upper surface of the metal interconnects 708. Thus, referring to Figure 7 , the semiconductor device structure 700 can also include a capping layer 710 disposed directly on the upper surface of the metal interconnect material 708. The capping layer 710 can be utilized to prevent the oxidation of the metal interconnect material 708 and, importantly, to prevent the metal interconnect material 708 from diffusing into additional dielectric materials formed over the partially fabricated semiconductor structure 700 in subsequent manufacturing processes, i.e., for multi-level interconnect structures. In some embodiments, the metal interconnect material 708, the molybdenum nitride barrier layer 706, and the capping layer 710 can together form an electrode for electrically interconnecting a plurality of semiconductor devices disposed in / on the substrate 702. In some embodiments, the capping layer 710 can include a molybdenum nitride film deposited according to embodiments of the present disclosure.

[0128] As another non-limiting example, the molybdenum nitride film of the present disclosure can include at least a portion of a gate electrode in a gate stack formed over a semiconductor channel region. More specifically, Figure 8A cross-sectional schematic view of a semiconductor device structure is shown, which includes a molybdenum nitride film deposited according to an embodiment of the present disclosure. The semiconductor device structure 800 may include a transistor structure, and the transistor structure includes a semiconductor body 816, and the semiconductor body includes a source region 802, a drain region 804, and a semiconductor channel region 806 disposed between the source region 802 and the drain region 804.

[0129] In some embodiments, the semiconductor device structure 800 may include an NMOS device, and both the semiconductor body 816 and the semiconductor channel region 806 may be p-type doped, and both the source region 802 and the drain region 804 may be n-type doped. In alternative embodiments, the semiconductor device structure 800 may include a PMOS device, and both the semiconductor body 816 and the semiconductor channel region 806 may be n-type doped, and both the source region 802 and the drain region 804 may be p-type doped. In some embodiments, the semiconductor body 816 may include substantially single-crystalline silicon.

[0130] Disposed on the semiconductor channel region 806 is a gate stack 808, which may include a gate dielectric 809 and a gate electrode 811. In some embodiments, the gate dielectric may include a silicon oxide interface layer 816 disposed directly on the semiconductor channel region 806 and a high-k dielectric layer 812 disposed directly on the interface layer 816. In some embodiments of the present disclosure, the high-k dielectric layer 812 may include at least one of the following: hafnium oxide (HfO2), tantalum oxide (Ta2O5), zirconium oxide (ZrO2), titanium oxide (TiO2), hafnium silicate (HfSiO x ), lanthanum oxide (La2O3), or a mixture / layer compound thereof.

[0131] The gate electrode 811 is disposed above the gate dielectric 809, and in some embodiments, directly on the gate dielectric 809. The gate electrode may include a molybdenum nitride film 810 deposited according to an embodiment of the present disclosure. Another metal film 814 may be disposed directly above the molybdenum nitride film 810 to complete the gate electrode 811. For example, the another metal film 814 may include a transition metal carbide (such as titanium carbide) or a transition metal nitride (such as titanium nitride).

[0132] In some embodiments of the present disclosure, the effective work function of the gate stack 808 disposed above the semiconductor channel region 806 may be adjusted by the deposition method used to deposit the molybdenum nitride film 810 and the average film thickness of the molybdenum nitride film 810. For example, the effective work function of the gate stack 808 including the molybdenum nitride film is less than when the average molybdenum nitride film thickness is less than less than less than or less than or less than or between and down can be in the range of about 4 eV to about 5 eV, or greater than 4, or greater than 4.5 eV, or greater than 4.75 eV

[0133] Thus, in some embodiments, the molybdenum nitride film comprises a part of a gate stack formed on a semiconductor channel region, wherein the effective work function of the gate stack is less than the average molybdenum nitride film thickness or less than or less than or less than or less than or less than or between and down greater than 4.0 eV, or greater than 4.5 eV, or greater than 4.75 eV, or even greater than 4.9 eV or between and 5 eV.

[0134] As a non - limiting example, Figure 9 shows the effective work function of a gate stack (disposed on a semiconductor channel region) including molybdenum nitride films with various average film thicknesses deposited according to embodiments of the present disclosure. Figure 9 Examination of shows that when the average film thickness of the molybdenum nitride layer decreases from about to or less than or less than or less than or less than or between and down the effective work function is greater than 4 eV, or greater than 4.25 eV, or greater than 4.5 eV, or greater than 4.75 eV, or greater than 4.8 eV or between 4 eV and 4.8 eV, or between 4.6 eV and 4.75 eV. In some embodiments, a gate stack disposed on a semiconductor channel region and including a molybdenum nitride film has an effective work function greater than 4.75 eV at an average molybdenum nitride film thickness equal to or less than .

[0135] As another non - limiting example, Figure 10 shows the effective work function of a gate stack including molybdenum nitride films with varying average film thicknesses deposited using an exemplary cyclic deposition process 300( Figure 3 ). Figure 10Examination shows that when the average film thickness of the molybdenum nitride film decreases from about to , the corresponding effective work function of the gate stack including the molybdenum nitride film remains substantially unchanged at a value of about 4.75 eV. Thus, in some embodiments, the molybdenum nitride film of the present disclosure can form a part of a gate stack having an effective work function greater than 4.6 eV, or greater than 4.75 eV, or greater than 4.8 eV, or greater than 4.9 eV, or greater than 5.0 eV, or between 4.6 eV and 4.9 eV, or even between 4.75 eV and 4.8 eV when the average molybdenum nitride film thickness is less than or less than or less than or less than or less than or even between about and .

[0136] In some device applications, such as PMOS device structures, the ability to form a gate stack including a molybdenum nitride film in which the effective work function of the gate stack is substantially independent of the average film thickness of the molybdenum nitride film may be required.

[0137] Thus, in some embodiments, the gate stack can include a molybdenum nitride film having an average film thickness between about and , where the effective work function of the gate stack can have an effective work function substantially independent of the average film thickness of the molybdenum nitride film. Additionally, the gate stack including the molybdenum nitride film can have an effective work function of about 4.8 eV that is substantially constant at an average film thickness between about and . Further, the gate stack can include a molybdenum nitride film deposited by a cyclic deposition process that includes contacting a substrate sequentially with a molybdenum halide precursor, a nitrogen precursor, and a reducing agent, where the gate stack has an effective work function of about 4.8 eV that is substantially constant at an average molybdenum nitride film thickness between about and .

[0138] As another non-limiting application of the molybdenum nitride film of the present disclosure, Figure 11 Another cross-sectional schematic view of an exemplary semiconductor device structure is shown, which includes a molybdenum nitride film deposited according to an embodiment of the present disclosure and specifically shows a FinFet semiconductor device structure.

[0139] More specifically, Figure 11FIG. 0 shows a non-limiting example of a semiconductor device structure 1100 that includes an exemplary FinFET device structure. The semiconductor device structure 1100 may include a substrate 1102, which may include a bulk silicon (Si) substrate. The substrate 1102 may be doped with a p-type dopant (for NMOS-type FinFET devices) and / or with an n-type dopant (for PMOS-type FinFET devices).

[0140] The semiconductor device structure 1100 may further include isolation regions 1104, which may include shallow trench isolation (STI) regions. The semiconductor device structure 1100 may further include fin structures 1106 that extend above the top surface of the isolation regions 1104, and the fin structures 1106 are partially buried under a gate stack 1108 that includes a semiconductor channel region. A gate dielectric 1110 may be disposed above the sidewalls of the fin structures 1106 and the gate dielectric 1110 may include silicon oxide and / or a high-k dielectric material.

[0141] A gate electrode may be disposed on the gate dielectric 1110 to provide electrical contact with the semiconductor channel region, and the gate electrode may include a molybdenum nitride film 1112 deposited according to an embodiment of the present disclosure, and may include an additional metal film 1114 that may include a transition metal carbide or a transition metal nitride. In some embodiments of the present disclosure, the semiconductor device structure 1100 may further include source / drain regions 1116, which are adjacent to the semiconductor channel region.

[0142] As another non-limiting application of the molybdenum nitride film of the present disclosure, Figure 12 FIG. 11 shows another schematic diagram of an exemplary semiconductor device structure that includes a molybdenum nitride film deposited according to an embodiment of the present disclosure, and specifically shows a gate-all-around (GAA) semiconductor device structure.

[0143] More specifically, the semiconductor device structure 1200 may include a semiconductor substrate 1202 and a dielectric film 1204 disposed above the substrate 1202. In addition, the GAA device structure may include semiconductor wires 1206 (doped p-type or n-type), where a gate dielectric 1208 is disposed around and encloses the semiconductor wires 1206. A gate electrode may be disposed around the region of the semiconductor wires 1206, and may include a molybdenum nitride film 1210 deposited according to an embodiment of the present disclosure. Additionally, the gate electrode may include another metal film 1212, such as a transition metal carbide or a transition metal nitride.

[0144] Embodiments of the present disclosure also provide a semiconductor device structure including a molybdenum nitride film. In some embodiments, the semiconductor device structure may include: a semiconductor channel region; and a gate stack directly disposed on the semiconductor channel region, wherein the gate stack includes: a gate dielectric directly disposed on the semiconductor channel region and a gate electrode including a molybdenum nitride film directly disposed on the gate dielectric.

[0145] In some embodiments, the semiconductor device structure may include a molybdenum nitride film having a resistivity of less than 1000 μΩ-cm, or less than 500 μΩ-cm, or less than 250 μΩ-cm, or between 250 μΩ-cm and 1000 μΩ-cm at an average molybdenum nitride film thickness of less than or less than or less than or less than or between and In some embodiments, the semiconductor device structure may include a molybdenum nitride film having a resistivity of less than 250 μΩ-cm at an average film thickness of less than In some embodiments, the semiconductor device structure may include a molybdenum nitride film having a resistivity of less than 500 μΩ-cm at an average film thickness of less than

[0146] In some embodiments, the semiconductor device structure including a molybdenum nitride film may include a MoN phase and a Mo2N phase. In some embodiments, the semiconductor device structure includes a physically continuous molybdenum nitride film having an average film thickness of less than or less than or less than or less than or between and In some embodiments, the semiconductor device structure may include a molybdenum nitride film that may be amorphous or crystalline.

[0147] In some embodiments, the semiconductor device structure including a molybdenum nitride film may include a PMOS work function metal device structure, a FinFET semiconductor device structure, or a gate-all-around semiconductor device structure.

[0148] Embodiments of the present disclosure may also include a reaction system configured to deposit the molybdenum nitride film of the present disclosure. More specifically, Figure 13Schematically shown is a reaction system 1300 including a reaction chamber 1302, the reaction system further including means for maintaining a substrate (not shown) at a predetermined pressure, temperature, and ambient conditions and for selectively exposing the substrate to various gases. A precursor reactant source 1304 may be coupled to the reaction chamber 1302 via a conduit or other suitable member 1304A and may be further coupled to a manifold, valve control system, mass flow control system, or means for controlling the gaseous precursor from the precursor reactant source 1304. The precursor, reactant (not shown) supplied by the precursor reactant source 1304 may be liquid or solid at room temperature and standard atmospheric pressure conditions. Such precursors may be vaporized within a reactant source vacuum container, which may be maintained at or above the vaporization temperature within the precursor source chamber. In such embodiments, the vaporized precursor may be transported with a carrier gas (e.g., an inert or noble gas), and then the vaporized precursor is fed into the reaction chamber 1302 through a conduit 1304AA. In other embodiments, under standard conditions, the precursor may be a vapor. In such embodiments, the precursor does not need to be vaporized and may not require a carrier gas. For example, in one embodiment, the precursor may be stored in a gas cylinder. The reaction system 1300 may further include additional precursor reactant sources, such as precursor reactant sources 1306 and 1308, which may also be coupled to the reaction chamber via conduits 1306A and 1306B as described above. In some embodiments, the precursor reactant source 1304 may comprise molybdenum halide, the precursor reactant source 1306 may comprise a nitrogen precursor, and the precursor reactant source 1308 may comprise a reducing agent.

[0149] A purge gas source 1310 may also be coupled to the reaction chamber 1302 via a conduit 1310A and selectively supply various inert or noble gases to the reaction chamber 1302 to assist in removing precursor gases or exhaust gases from the reaction chamber. The various inert or noble gases that may be supplied may be sourced from solid, liquid, or stored gaseous forms.

[0150] Figure 13The reaction system 1300 may also include system operation and control mechanisms 1312 that provide electrical circuitry and mechanical components to selectively operate valves, manifolds, pumps, and other equipment included in the reaction system 1300. Such circuitry and components are used to introduce precursors and purge gases from the respective precursor sources 1304, 1306, 1308 and the purge gas source 1310. The system operation and control mechanisms 1312 also control the timing of the gas pulse sequence, the temperature of the substrate and the reaction chamber, and the pressure of the reaction chamber, and provide various other operations necessary for the proper operation of the reaction system 1300. The operation and control mechanisms 1312 may include control software and electrically or pneumatically controlled valves to control the flow of precursors, reactants, and purge gases into and out of the reaction chamber 1302. The control system may include modules, such as software or hardware components, that perform certain tasks, such as FPGAs or ASICs. The modules may advantageously be configured to reside on an addressable storage medium of the control system and be configured to perform one or more processes.

[0151] Those skilled in the art will appreciate that other configurations of the reaction system of the present invention are possible, including different numbers and types of precursor reactant sources and purge gas sources. In addition, those skilled in the art should also understand that there are many arrangements of valves, conduits, precursor sources, and purge gas sources that can be used to achieve the goal of selectively feeding gases into the reaction chamber 1302. In addition, for the sake of simplicity of illustration, many components have been omitted in the schematic illustration of the reaction system, and such components may include, for example, various valves, manifolds, purifiers, heaters, containers, vents, and / or bypasses.

[0152] The exemplary embodiments of the present disclosure described above do not limit the scope of the present invention, since these embodiments are merely examples of embodiments of the present invention, which is defined by the appended claims and their legal equivalents. Any equivalent embodiments are intended to be included within the scope of the present invention. In fact, various modifications of the present disclosure, such as alternative available combinations of the elements described, will be apparent to those skilled in the art from the specification. Such modifications and embodiments are also intended to fall within the scope of the appended claims.

Claims

1. A method for depositing a molybdenum nitride film on a substrate surface by a cyclic deposition process, the method comprising: providing a substrate into a reaction chamber; and directly depositing a molybdenum nitride film on the surface of the substrate by performing one or more unit deposition cycles of the cyclic deposition process, wherein a unit deposition cycle comprises: contacting the substrate with a first gaseous reactant comprising a molybdenum precursor; and contacting the substrate with a second gaseous reactant comprising a nitrogen precursor, wherein the molybdenum precursor comprises an oxyhalide molybdenum precursor, wherein the oxyhalide molybdenum precursor comprises at least one of the following: molybdenum(V) oxytrichloride (MoOCl3), molybdenum(VI) oxytetrachloride (MoOCl4), or molybdenum(IV) dioxydichloride (MoO2Cl2), wherein the molybdenum nitride film has a roughness percentage of less than 1.5%.

2. The method according to claim 1, wherein the unit deposition cycle further comprises contacting the substrate with a third gaseous reactant comprising a reducing agent.

3. The method according to claim 2, wherein the substrate is contacted with the nitrogen precursor and the reducing agent simultaneously.

4. The method according to claim 2, wherein a purge cycle is performed between the process of contacting the substrate with the nitrogen precursor and the process of contacting the substrate with the reducing agent.

5. The method according to claim 2, wherein the reducing agent comprises at least one of the following: molecular hydrogen (H2), atomic hydrogen (H), synthesis gas (H2+N2), ammonia (NH3), hydrazine (N2H4), hydrazine derivatives, hydrogen-based plasmas, alcohols, aldehydes, carboxylic acids, boranes, amines, or silanes.

6. The method according to claim 1, wherein the nitrogen precursor comprises at least one of the following: molecular nitrogen (N2), ammonia (NH3), hydrazine (N2H4), hydrazine derivatives, or nitrogen-based plasmas.

7. The method according to claim 1, further comprising heating the substrate to a temperature of less than 450 °C.

8. The method according to claim 1, wherein the molybdenum precursor comprises at least one of the following: molybdenum pentachloride (MoCl5) or molybdenum hexachloride (MoCl6).

9. The method according to claim 1, wherein the molybdenum precursor comprises at least one of the following: Mo(NMe2)4, Mo(NEt2)4, Mo2(NMe2)6, Mo(tBuN)2(NMe2)2, Mo(tBuN)2(NEt2)2, Mo(NEtMe)4, Mo(NtBu)2(StBu)2, Mo(NtBu)2(iPr2AMD)2Mo(thd)3, MoO2(acac), MoO2(thd)2, MoO2(iPr2AMD)2Mo(CO)6, Mo(Cp)2H2, Mo(iPrCp)2H2, Mo(η 6 -ethylbenzene)2, MoCp(CO)2(η 3 -allyl) and MoCp(CO)2(NO).

10. The method according to claim 1, wherein the molybdenum nitride film has a resistivity of less than 750 μΩ-cm at an average molybdenum nitride film thickness of less than .

11. The method according to claim 1, wherein the molybdenum nitride film has a resistivity of less than 250 μΩ-cm at an average molybdenum nitride film thickness of less than .

12. The method according to claim 1, wherein the molybdenum nitride film has a resistivity of less than 400 μΩ-cm at an average molybdenum nitride film thickness of less than .

13. The method according to claim 1, wherein the composition of the molybdenum nitride film comprises MoN phase and Mo2N phase.

14. The method according to claim 1, wherein the molybdenum nitride film is directly deposited on a dielectric surface.

15. The method according to claim 1, wherein the molybdenum nitride film is physically continuous at an average film thickness less than .

16. The method according to claim 1, wherein the molybdenum nitride film forms part of a gate stack disposed over a semiconductor channel region, wherein the gate stack has an effective work function greater than 4.6 eV at an average molybdenum nitride film thickness less than .

17. The method according to claim 1, wherein the molybdenum nitride film forms part of a gate stack disposed on a semiconductor channel region, wherein the gate stack has an effective work function greater than 4.75 eV at an average molybdenum nitride film thickness less than .

18. The method according to claim 1, wherein the molybdenum nitride film forms part of a gate stack disposed on a semiconductor channel region, wherein the gate stack has an effective work function between 4.6 eV and 4.75 eV at an average molybdenum nitride film thickness between and .

19. The method according to claim 2, wherein the molybdenum nitride film forms part of a gate stack disposed on a semiconductor channel region, wherein the gate stack has a substantially constant effective work function of 4.75 eV at an average molybdenum nitride film thickness between and .

20. A reaction system configured to perform the method according to claim 1.

21. A semiconductor device structure comprising a molybdenum nitride film deposited by the method according to claim 1.

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