Deposition of vanadium-containing films

Abstract

The disclosed and claimed subject matter relates to a method for depositing vanadium-containing films, including vanadium nitride and vanadium oxynitride, the method generally comprising (i) contacting a substrate with vanadium oxytrichloride vapor in a deposition reactor, (ii) purging any unreacted vanadium oxytrichloride with an inert gas, (iii) contacting the substrate with a nitrogen-containing reactant in the deposition reactor, and (iv) purging any unreacted nitrogen-containing reactant with an inert gas. Additional steps may be included, such as (v) treating the substrate with a plasma to remove residual oxygen from the oxynitride film.

Description

[Technical field]

[0001] The subject matter disclosed and claimed herein relates to a method for depositing vanadium-containing films, including vanadium nitride and vanadium oxynitride, the method generally comprising: (i) contacting a substrate with vanadium oxytrichloride vapor in a deposition reactor; (ii) purging any unreacted vanadium oxytrichloride with an inert gas; (iii) contacting the substrate with a nitrogen-containing reactant in the deposition reactor; and (iv) purging any unreacted nitrogen-containing reactant with an inert gas. Additional steps may be included, such as treating the substrate with a nitrogen plasma to remove residual oxygen from the oxynitride film. [Background technology]

[0002] Thin films, and particularly thin metal-containing films, have a variety of important applications, for example in nanotechnology and the manufacture of semiconductor devices. Examples of such applications include high refractive index optical coatings, anti-corrosion coatings, photocatalytic self-cleaning glass coatings, biocompatible coatings, dielectric capacitor layers and gate dielectric insulating films in field effect transistors (FETs), capacitor electrodes, gate electrodes, adhesive diffusion barriers, and integrated circuits. Metal and dielectric thin films are also used in microelectronic applications, such as high-κ dielectric oxides for dynamic random access memories (DRAMs) and ferroelectric perovskites used in infrared detectors and non-volatile ferroelectric random access memories (NV-FeRAMs).

[0003] A variety of precursors can be used to form metal-containing thin films, and a variety of deposition techniques can be used. Such techniques include reactive sputtering, ion-assisted deposition, sol-gel deposition, chemical vapor deposition (CVD) (also known as metalorganic CVD or MOCVD), and atomic layer deposition (ALD) (also known as atomic layer epitaxy). CVD and ALD processes are increasingly being used because they have the advantages of enhanced composition control, high film uniformity, and effective control of doping.

[0004] A CVD process is a chemical process by which precursors are used to form a thin film on a substrate surface. In a typical CVD process, precursors are passed over the surface of a substrate (e.g., a wafer) in a low-pressure or atmospheric pressure reactor. The precursors react and / or decompose on the substrate surface to produce a thin film of deposited material. Volatile by-products are removed by gases flowing through the reactor. The thickness of the deposited film is difficult to control because it depends on the coordination of many parameters, such as temperature, pressure, volume and uniformity of gas flow, chemical depletion effects, and time.

[0005] ALD is also a method for the deposition of thin films. ALD is a self-limiting, sequential, unique film growth technique based on surface reactions that provide precise thickness control and allow the deposition of conformal thin films of materials provided by precursors on substrate surfaces of various compositions. In ALD, the precursors are separated during the reaction. A first precursor is passed over the substrate surface to produce a monolayer on the substrate surface. Any excess unreacted precursor is pumped out of the reactor. A second precursor is then passed over the substrate surface and reacts with the first precursor to form a second monolayer on the substrate surface, over the first formed monolayer. This cycle is repeated until a film of the desired thickness is produced.

[0006] However, the continued reduction in size of microelectronic components, e.g., semiconductor devices, has created several technical challenges and increased demand for improved thin film technology. In particular, microelectronic components may include features on or in a substrate that require filling, e.g., to form conductive paths or to form interconnects. Filling such features can be challenging, especially for smaller microelectronic components, as the features may become thinner or narrower. Thus, complete filling of a feature, e.g., by ALD, requires infinitely long cycle times as the feature thickness approaches zero. Moreover, if the feature thickness becomes narrower than the size of the precursor molecules, the feature cannot be completely filled. As a result, hollow channels may remain in the center of the feature when ALD is performed. The presence of such hollow channels in a feature is undesirable, as they may lead to device failure. Accordingly, there is significant interest in developing thin film deposition methods, particularly ALD methods, that can selectively grow films on one or more substrates and provide improved filling of features on or in the substrate, including depositing metal-containing films in a manner that substantially fills the features without any voids.

[0007] CVD and ALD are particularly attractive for producing conformal metal-containing films on substrates, such as silicon, silicon oxide, metal nitrides, metal oxides, and other metal-containing layers, using their metal-containing precursors. As mentioned above, in these techniques, the vapor of a volatile metal complex is introduced into a process reactor where it contacts the surface of a silicon wafer, where a chemical reaction occurs, thus depositing a thin film of a pure metal or metal compound. CVD occurs when a precursor reacts at the wafer surface, either thermally or with a chemical simultaneously added in the process reactor, and film growth occurs in a steady-state deposition. CVD can be applied in a continuous or pulsed mode to obtain a desired film thickness. In ALD, a precursor is chemisorbed as a self-saturating monolayer on the wafer, the excess unreacted precursor is purged with an inert gas, such as argon, and then an excess chemical is added that reacts with the monolayer of the chemisorbed precursor to form a metal or metal compound. The excess chemical is then purged with an inert gas. This cycle can then be repeated multiple times to create the metal or metal compound to the desired thickness with atomic precision, since the chemical absorption of the precursors and chemicals is self-limiting. ALD provides the deposition of ultrathin, on-the-fly continuous metal-containing films with precise control of film thickness, excellent film thickness uniformity, and remarkable conformal film growth to evenly coat deeply etched and highly convoluted structures, such as interconnect vias and trenches. Thus, ALD is typically preferred for the deposition of thin films into features with high aspect ratios.

[0008] Transition metal nitrides are used in the semiconductor industry because of their good barrier properties, high temperature stability, corrosion resistance and low resistivity. Vanadium nitride is particularly attractive because of its almost metallic low resistivity, less than 100 μΩcm. Vanadium nitride films are primarily deposited by reactive sputtering, high temperature nitridation of metallic vanadium layers, chemical vapor deposition and atomic layer deposition.

[0009] Suitable metal precursors for ALD include those that are thermally stable to prevent any thermal decomposition that occurs during the chemical absorption step, yet are chemically reactive towards the added chemicals. Furthermore, it is important that the metal precursor be monomeric for maximum volatility and complete evaporation leaving only trace amounts of non-volatile residue. It is also desirable for the precursor to be liquid at room temperature.

[0010] In this regard, the Journal of Vacuum Science and Technology, A37, 061505, (2019) describes a plasma-enhanced atomic layer deposition process for vanadium nitride (VN) using tetrakis(dimethylamido)vanadium and nitrogen plasma over a deposition temperature range of 150 °C to 300 °C. The authors characterize the films using X-ray photoelectron spectroscopy, X-ray diffraction, and spectroscopic ellipsometry. They demonstrate a stable VN growth window in the range of 250 °C to 350 °C, below which deposition temperatures lead to incomplete reactions between the precursors.

[0011] ALD deposition on silicon substrates and polymer films using tetrakis(ethylmethylamino)vanadium and NH3 plasma at deposition temperatures ranging from 70°C to 150°C has been described. See Appl. Phys. Lett., 102, 111910 (2013). X-ray photoelectron spectroscopy revealed a composition close to stoichiometric VN, while X-ray diffraction indicated a δ-VN crystal structure. Resistivity was as low as 200 μΩ for the deposited films and was further reduced to 143 μΩcm and 93 μΩcm by annealing in N2 and H2 / He / N2, respectively. Tetrakis(dimethylamido)vanadium and tetrakis(ethylmethylamino)vanadium are organometallic precursors with low thermal stability, however. Thermal decomposition leads to parasitic CVD and poor film conformality in high aspect ratio features. Therefore, more thermally stable precursors are desirable for the deposition of conformal vanadium nitride films.

[0012] Other ALD depositions have been described. For example, Chemical Vapor Deposition, 6(2), 59-63 (2000) describes the atmospheric plasma chemical vapor deposition of vanadium oxynitride using the reaction of vanadium oxychloride with ammonia. Atmospheric pressure chemical vapor deposition of vanadium nitride and oxynitride coatings by reaction of VCl4 and NH3 at 350-650 °C is described in J. Material Chemistry, 11, 3120 (2001). Furthermore, Chemistry Europe, 21, 4286-4290 (2000) describes the synthesis of vanadium nitride and vanadium oxynitride by atmospheric pressure CVD of vanadium(IV) chloride and vanadium oxytrichloride with hexamethyldisilazane (HMDS) at 300-500 °C. When these films are deposited by reaction of VOCl3 with HMDS, they consist of mixed phases of vanadium oxynitride and V2O3. Summary of the Invention [Problem to be solved by the invention]

[0013] Notwithstanding the above, atmospheric pressure chemical vapor deposition cannot be used to deposit thin, conformal vanadium nitride films. Thus, a need exists for an ALD process for depositing thin, conformal vanadium nitride films having low resistivity as described herein. [Means for solving the problem]

[0014] In one embodiment, the disclosed and claimed subject matter relates to a method for depositing vanadium-containing films, including vanadium nitrides and vanadium oxynitrides. The method generally comprises: (i) contacting a substrate with vanadium oxytrichloride vapor in a deposition reactor; (ii) purging any unreacted vanadium oxytrichloride with an inert gas; (iii) contacting a substrate with a nitrogen-containing reactant (e.g., ammonium gas) in a deposition reactor; and (iv) optionally purging any unreacted nitrogen-containing reactant with an inert gas. In a further aspect of this embodiment, the method comprises (v) treating the substrate with a plasma (e.g., nitrogen plasma) to remove residual oxygen from the vanadium-containing film. In a further aspect, the method consists essentially of steps (i), (ii), (iii), and (iv). In a further aspect, the method consists essentially of steps (i), (ii), (iii), (iv), and (v). In a further embodiment, the method comprises steps (i), (ii), (iii) and (iv).In a further embodiment, the method comprises steps (i), (ii), (iii), (iv) and (v).

[0015] Unlike related art processes, the disclosed and claimed process is carried out under ALD conditions to provide highly conformal films of vanadium nitride. The process is also carried out under low pressure, preferably less than about 50 Torr, more preferably less than about 20 Torr, and more preferably less than about 10 Torr.

[0016] This Summary section does not identify every aspect and / or additional novel aspects of the disclosed and claimed subject matter. Instead, this Summary provides only a preliminary discussion of novel and different aspects and corresponding points over conventional and known techniques. For further details and / or possible aspects of the disclosed and claimed subject matter and aspects, the reader is directed to the Detailed Description section and corresponding figures, which are discussed further below.

[0017] The order of discussion of the various steps described herein is presented for clarity. In general, the steps disclosed herein can be performed in any suitable order. Moreover, although each of the various features, techniques, configurations, etc. disclosed herein may be discussed in different locations herein, it is contemplated that each concept can be implemented independently of one another or in combination with one another as appropriate. Thus, the subject matter disclosed and claimed can be embodied and viewed in many different ways. [Brief description of the drawings]

[0018] The accompanying drawings, which are included to provide a further understanding of the disclosed subject matter, and which are incorporated in and constitute a part of this specification, illustrate embodiments of the disclosed subject matter and, together with the description, explain the principles of the disclosed subject matter.

[0019] [Figure 1] FIG. 1 shows the dependence of film thickness deposited by VOCl and ammonia ALD processes on VOCl pulse time.

[0020] [Diagram 2] FIG. 2 shows the dependence of film thickness deposited by VOCl3 and ammonia ALD processes on ammonia pulse time.

[0021] [Diagram 3] FIG. 3 shows a TEM cross-section of a trench-patterned substrate in accordance with an embodiment of the disclosed and claimed subject matter. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0022] definition Unless otherwise stated, the following terms used in the specification and claims have the following meanings in this application:

[0023] For purposes of this invention and the claims, the numbering system for the Periodic Table Groups follows the IUPAC Periodic Table of the Elements.

[0024] The term "and / or" used in a phrase, e.g., "A and / or B," is intended herein to encompass "A and B," "A or B," or "A" and "B."

[0025] The terms "substituents," "radicals," "groups," and "moieties" may be used interchangeably.

[0026] As used herein, the terms "metal-containing complex" (or more simply "complex") and "precursor" are used interchangeably and refer to metal-containing molecules or compounds that can be used to prepare metal-containing films by vapor deposition processes, such as ALD or CVD. The metal-containing complexes can be deposited on, adsorbed on, decomposed on, delivered to, and / or passed over a substrate or surface thereof to form a metal-containing film. In one or more embodiments, the metal-containing complexes disclosed herein are metal halide complexes, particularly molybdenum chloride complexes.

[0027] As used herein, the term "metal-containing film" includes not only elemental metal films, as more fully defined below, but also films that contain a metal along with one or more elements, such as metal oxide films, metal nitride films, metal silicide films, metal carbide films, and the like. As used herein, the terms "elemental metal film" and "pure metal film" are used interchangeably and refer to a film that consists of, or consists essentially of, a pure metal. For example, an elemental metal film can comprise 100% pure metal, or an elemental metal film can comprise at least about 70%, at least about 80%, at least about 90%, at least about 95%, at least about 96%, at least about 97%, at least about 98%, at least about 99%, or at least about 99.9% pure metal along with one or more impurities. Unless otherwise specified, the term "metal film" is understood to mean an elemental metal film.

[0028] As used herein, the term "vapor deposition process" is used to refer to any type of vapor deposition technique, including, but not limited to, CVD and ALD. In various embodiments, CVD can take the form of conventional (i.e., continuous flow) CVD, liquid injection CVD, or photoassisted CVD. CVD can also take the form of a pulsed technique, i.e., pulsed CVD. ALD is used to form a metal-containing film by evaporating at least one metal complex disclosed herein onto and / or passing it over a substrate surface. For conventional ALD processes, see, for example, George SM, et al. J. Phys. Chem., 1996, 100, 13121-13131. In other embodiments, ALD can take the form of conventional (i.e., pulsed injection) ALD, liquid injection ALD, photoassisted ALD, plasma-assisted ALD, or plasma-promoted ALD. The term "vapor deposition process" further includes various vapor deposition techniques described in Chemical Vapour Deposition: Precursors, Processes, and Applications; Jones, AC; Hitchman, ML, Eds. The Royal Society of Chemistry: Cambridge, 2009; Chapter 1, pp. 1-36.

[0029] As used herein, the term "feature" refers to an opening in a substrate that can be defined by one or more sidewalls, a bottom surface, and a top corner. In various embodiments, the feature can be a via, a trench, a contact, a dual damascene, etc.

[0030] As used herein, the terms "selective growth," "selectively grown," and "selectively grown" may be used synonymously and refer to film growth on at least a portion of a first substrate and no film growth on the remainder of the first substrate, as well as greater film growth on at least a portion of the first substrate compared to the remainder of the first substrate. For example, selective growth may include film growth on the lower portion of a feature, while less film growth or no film growth may occur on the top of the feature or outside of the feature. For two or more substrates, the terms "selective growth," "selectively grown," and "selectively grown" also encompass film growth on the first substrate and no film growth on the second substrate (or third substrate, or fourth substrate, or fifth substrate, etc.), as well as greater film growth on the first substrate than on the second substrate (or third substrate, or fourth substrate, or fifth substrate, etc.).

[0031] The terms "about" and "approximately," when used in reference to a measurable numerical value, refer to the stated value of that numerical value, and all values ​​that are within experimental error of the stated value, or within a percentage of the stated value (e.g., ±10%, ±5%), whichever is greater (e.g., within a 95% confidence limit of the mean).

[0032] "Halo" or "halide" refers to halogens (e.g., F, Cl, Br, and I).

[0033] The section headings used herein are for organizational purposes only and should not be construed as limiting the subject matter described. All documents or portions of documents cited in this application, including but not limited to patents, patent applications, articles, books, and papers, are expressly incorporated herein by reference in their entirety for any purpose. In the event that any of the incorporated documents and similar materials defines a term in a manner that contradicts the definition of that term in this application, this application controls.

[0034] Detailed Description It should be understood that both the general description above and the detailed description below are exemplary and explanatory and are not intended to limit the claimed subject matter. The objects, features, advantages and concepts of the disclosed subject matter will be apparent to those skilled in the art from the description provided herein, and the disclosed subject matter can be readily implemented by those skilled in the art based on the description made clear herein. The description of any "preferred embodiments" and / or examples illustrating preferred modes for implementing the disclosed subject matter are included for illustrative purposes and are not intended to limit the scope of the claims.

[0035] In addition, it will be apparent to those skilled in the art how various modifications can be made to the disclosed subject matter based on the embodiments described in the specification without departing from the spirit and scope of the subject matter disclosed herein.

[0036] It should be understood that in the embodiments described below, the steps of the method can be performed in various orders, sequentially or simultaneously (e.g., between at least some of the other steps), and any combination thereof. Each step of supplying a precursor and a nitrogen-containing source gas can be performed by varying the duration for which they are supplied to vary the stoichiometric composition of the resulting dielectric film.

[0037] In one embodiment, the disclosed and claimed subject matter relates to a method for depositing vanadium-containing films, including vanadium nitride and vanadium oxynitride. The method generally includes: (i) contacting a substrate with vanadium oxytrichloride vapor in a deposition reactor; (ii) purging any unreacted vanadium oxytrichloride with an inert gas; (iii) contacting a substrate with a nitrogen-containing reactant (e.g., ammonia gas) in a deposition reactor; and (iv) optionally purging any unreacted nitrogen-containing reactant with an inert gas. In a further aspect of this embodiment, the method consists essentially of steps (i), (ii), (iii), and (iv). In a further aspect of this embodiment, the method consists of steps (i), (ii), (iii), and (iv).

[0038] In one embodiment, the disclosed and claimed subject matter relates to a method for depositing vanadium-containing films, including vanadium nitride and vanadium oxynitride. The method generally includes: (i) contacting a substrate with vanadium oxytrichloride vapor in a deposition reactor; (ii) purging any unreacted vanadium oxytrichloride with an inert gas; (iii) contacting a substrate with a nitrogen-containing reactant (e.g., ammonia gas) in a deposition reactor; (iv) optionally purging any unreacted nitrogen-containing reactant with an inert gas; and (v) treating the substrate with a plasma (e.g., nitrogen plasma, hydrogen plasma) to remove residual oxygen from the vanadium-containing film. In a further aspect of this embodiment, the method consists essentially of steps (i), (ii), (iii), (iv) and (v). In a further aspect of this embodiment, the method consists of steps (i), (ii), (iii), (iv) and (v).

[0039] Vanadium oxytrichloride supply

[0040] As described above, step (i) of the disclosed and claimed method includes contacting a substrate with vanadium oxytrichloride vapor. Vanadium oxytrichloride is highly suitable for use as a volatile precursor for ALD and plasma enhanced atomic layer deposition (PEALD). As used herein, the term "atomic layer deposition process" refers to a self-limiting (e.g., the amount of film material deposited in each reaction cycle is constant), sequential surface chemistry that deposits films of materials on substrates of various compositions.

[0041] In another embodiment, the pulse time of the vanadium oxytrichloride vapor is about 0.1 seconds to about 3 seconds. In another embodiment, the pulse time of the vanadium oxytrichloride vapor is about 0.3 seconds to about 3 seconds. In another embodiment, the pulse time of the vanadium oxytrichloride vapor is about 0.1 seconds. In another embodiment, the pulse time of the vanadium oxytrichloride vapor is about 0.25 seconds. In another embodiment, the pulse time of the vanadium oxytrichloride vapor is about 0.5 seconds. In another embodiment, the pulse time of the vanadium oxytrichloride vapor is about 1 second. In another embodiment, the pulse time of the vanadium oxytrichloride vapor is about 1.5 seconds. In another embodiment, the pulse time of the vanadium oxytrichloride vapor is about 2 seconds.

[0042] In one embodiment, the vanadium oxytrichloride vapor is separated from the other precursors prior to and / or during introduction into the reactor. This process avoids pre-reaction of the metal precursor with any of the other materials.

[0043] In other embodiments, vanadium oxytrichloride vapor is instead exposed to the substrate along with other reactants (e.g., ammonia vapor, and / or other precursors or chemicals). This process allows for the growth of the film to proceed by self-limiting control of the surface reactions, the pulse length of each precursor or chemical, and the deposition temperature. It should be noted, however, that the growth of the film ceases once the surface of the substrate is saturated with vanadium oxytrichloride vapor.

[0044] In other embodiments, a flow of argon and / or other gas is used as a carrier gas to help deliver vanadium oxytrichloride vapor to the reactor during the precursor pulse.

[0045] Vanadium oxytrichloride purging process

[0046] As noted above, step (ii) of the disclosed and claimed method involves purging any unreacted vanadium oxytrichloride with an inert gas, which removes excess unabsorbed complex from the process reactor.

[0047] In one embodiment, for example, the purge time varies from about 1 second to about 90 seconds. In one embodiment, for example, the purge time varies from about 15 seconds to about 90 seconds. In one embodiment, for example, the purge time varies from about 15 seconds to about 60 seconds. In another embodiment, the purge time is about 30 seconds. In another embodiment, the purge time is about 60 seconds. In another embodiment, the purge time is about 90 seconds.

[0048] In one embodiment, the purge gas comprises argon, hi another embodiment, the purge gas comprises nitrogen.

[0049] Nitrogen-Containing Reactant Treatment

[0050] As noted above, step (iii) of the disclosed and claimed method includes contacting the substrate with a nitrogen-containing reactant in a deposition reactor for a period of time. In one embodiment, the nitrogen-containing reactant includes one or more of ammonia, hydrazine, monoalkylhydrazine, and dialkylhydrazine. In another embodiment, the nitrogen-containing reactant includes ammonia gas.

[0051] In one embodiment, for example, the pulse time of the nitrogen-containing reactant varies from about 0.5 seconds to about 5 seconds. In one embodiment, for example, the pulse time of the nitrogen-containing reactant is about 2.5 seconds. In one embodiment, for example, the pulse time of the nitrogen-containing reactant is about 5 seconds.

[0052] Optional Nitrogen-Containing Reactant Purge Step

[0053] As noted above, step (iv) of the disclosed and claimed method optionally includes purging any unreacted nitrogen-containing reactant with an inert gas. Purging with an inert gas removes any remaining nitrogen-containing reactant from the process reactor. In one embodiment, the purge gas includes argon. In another embodiment, the purge gas includes nitrogen. As one skilled in the art will recognize, in many instances, if not most instances, the disclosed and claimed process includes a step of purging the unreacted nitrogen-containing reactant. One exception where purging of the nitrogen-containing reactant does not occur is, for example, when the unreacted nitrogen-containing reactant gas serves as a nitrogen source for a subsequent plasma treatment (described below) (described below).

[0054] In one embodiment, for example, the purge time of the optional nitrogen-containing reactant varies from about 15 seconds to about 90 seconds. In one embodiment, for example, the purge time of the optional nitrogen-containing reactant varies from about 15 seconds to about 60 seconds. In one embodiment, the purge time of the optional nitrogen-containing reactant is about 30 seconds. In one embodiment, the purge time of the optional nitrogen-containing reactant is about 60 seconds. In one embodiment, the purge time of the optional nitrogen-containing reactant is about 90 seconds.

[0055] Plasma treatment

[0056] As noted above, step (v) of the disclosed and claimed method involves treating the substrate with a nitrogen plasma or a hydrogen plasma to remove residual oxygen from the vanadium-containing film formed during the previous step.

[0057] In one embodiment, the use of plasma constitutes a direct plasma generation process, where the plasma is generated directly in the reactor, while in another embodiment, the use of plasma constitutes a remote plasma generation process, where the plasma is generated outside the reactor and fed into the reactor.

[0058] In the case where a nitrogen plasma is used, the nitrogen source can include nitrogen (N2), ammonia, hydrazine, monoalkylhydrazine, dialkylhydrazine. In this regard, and as noted above, in the case where the nitrogen plasma relies on ammonia as the nitrogen source, this optional nitrogen-containing reactant purging step (iv) can be omitted.

[0059] Operating conditions

[0060] As noted above, the vanadium deposition process disclosed and claimed can be efficiently carried out under ALD conditions that are highly favorable to provide highly conformal films of vanadium nitride.

[0061] In one embodiment, a substrate (e.g., silicon oxide, aluminum oxide (Al2O3), titanium nitride (TiN), silicon oxide (SiO2), and zirconium oxide (ZrO2)) is heated on a heater pedestal in a reactor that is initially exposed to a vanadium oxytrichloride precursor to allow the complex to chemisorb onto the surface of the substrate. In one embodiment, the substrate temperature is from about 300°C to about 600°C. In a further aspect of this embodiment, the substrate temperature is from about 350°C to about 550°C. In a further aspect of this embodiment, the substrate temperature is from about 400°C to about 500°C.

[0062] In another embodiment, the reactor pressure for deposition by the disclosed and claimed processes is about 50 Torr or less. In another embodiment, the reactor pressure for deposition by the disclosed and claimed processes is about 40 Torr or less. In another embodiment, the reactor pressure for deposition by the disclosed and claimed processes is about 30 Torr or less. In another embodiment of this embodiment, the reactor pressure is about 20 Torr or less. In another embodiment of this embodiment, the reactor pressure is about 10 Torr or less. In another embodiment of this embodiment, the reactor pressure is about 5 Torr or less.

[0063] Cycle and process sequence

[0064] In the above embodiment, as well as other embodiments described herein, the recited steps (e.g., (i)-(iv) or (i)-(v)) define one cycle of the method. It should be understood that one cycle can be repeated until the desired thickness of the film is obtained.

[0065] It should be understood that in the embodiments described herein, the steps of the method can be performed in various orders, sequentially or simultaneously (e.g., between at least some of the other steps), and any combination thereof. Furthermore, each step of providing vanadium oxytrichloride and a nitrogen source can be performed by varying the duration for providing them to change the composition of the film. EXAMPLES

[0066] Example Process

[0067] In one exemplary embodiment of the disclosed and claimed subject matter, vanadium-containing films, including vanadium nitride and vanadium oxynitride, are formed using an ALD deposition method that includes the following steps. a. providing a substrate in a reactor; b. introducing a vapor comprising vanadium oxytrichloride into the reactor; c. chemically absorbing vanadium oxytrichloride onto the substrate; d. purging unreacted vanadium oxytrichloride with a purge gas; e. introducing a nitrogen source into the reactor; and f. Optionally purging any nitrogen source. In this exemplary embodiment, the nitrogen source includes one or more of nitrogen (N2), ammonia, hydrazine, monoalkylhydrazine, and dialkylhydrazine.

[0068] In another exemplary embodiment of the disclosed and claimed subject matter, a vanadium nitride film is formed using an ALD deposition method that includes the following steps. a. providing a substrate in a reactor; b. introducing a vapor comprising vanadium oxytrichloride into the reactor; c. chemically absorbing vanadium oxytrichloride onto the substrate; d. purging unreacted vanadium oxytrichloride with a purge gas; e. introducing ammonia vapor into the reactor; f. Optionally, purging any ammonia. g. introducing nitrogen, hydrogen or ammonia vapor into the reactor; h. applying a direct or remote plasma into the reactor to remove residual impurities from the film; and i. purging the reactor of nitrogen, hydrogen or ammonia.

[0069] film

[0070] The disclosed and claimed subject matter further includes membranes prepared by the methods described herein.

[0071] In one embodiment, the film formed by the methods described herein has vias or other topographical features with an aspect ratio of about 1 to about 60. In a further embodiment of this embodiment, the aspect ratio is about 1 to about 50. In a further embodiment of this embodiment, the aspect ratio is about 1 to about 40. In a further embodiment of this embodiment, the aspect ratio is about 1 to about 30. In a further embodiment of this embodiment, the aspect ratio is about 1 to about 20. In a further embodiment of this embodiment, the aspect ratio is about 1 to about 10. In a further embodiment of this embodiment, the aspect ratio is greater than about 1. In a further embodiment of this embodiment, the aspect ratio is greater than about 2. In a further embodiment of this embodiment, the aspect ratio is greater than about 5. In a further embodiment of this embodiment, the aspect ratio is greater than about 10. In a further embodiment of this embodiment, the aspect ratio is greater than about 15. In further aspects of this embodiment, the aspect ratio is greater than about 20. In further aspects of this embodiment, the aspect ratio is greater than about 30. In further aspects of this embodiment, the aspect ratio is greater than about 40. In further aspects of this embodiment, the aspect ratio is greater than about 50.

[0072] In another embodiment, the film produced by the methods described herein has a resistivity in the range of about 150 to about 500. In a further embodiment of this embodiment, the film has a resistivity of about 175 to about 450. In a further embodiment of this embodiment, the film has a resistivity of about 175 to about 400. In a further embodiment of this embodiment, the film has a resistivity of about 175 to about 350. In a further embodiment of this embodiment, the film has a resistivity of about 175 to about 300. In a further embodiment of this embodiment, the film has a resistivity of about 175 to about 250. In a further embodiment of this embodiment, the film has a resistivity of about 150. In a further embodiment of this embodiment, the film has a resistivity of about 175. In a further embodiment of this embodiment, the film has a resistivity of about 200. In a further embodiment of this embodiment, the film has a resistivity of about 250. In a further embodiment of this embodiment, the film has a resistivity of about 300. In a further aspect of this embodiment, the film has a resistivity of about 350. In a further aspect of this embodiment, the film has a resistivity of about 400. In a further aspect of this embodiment, the film has a resistivity of about 450. In a further aspect of this embodiment, the film has a resistivity of about 500.

[0073] example

[0074] Reference is now made to more specific embodiments of the present disclosure and experimental results supporting such embodiments. The examples provided below more fully describe the disclosed and claimed subject matter and should not be construed as limiting the disclosed subject matter in any way.

[0075] It will be apparent to those skilled in the art that various modifications and variations can be made to the disclosed subject matter and the specific examples given herein without departing from the spirit and scope of the disclosed subject matter. Accordingly, the disclosed subject matter, including the description given by way of the following examples, is intended to cover modifications and variations of the disclosed subject matter that fall within the scope of any claims and equivalents thereof.

[0076] Example 1

[0077] Conditions: Deposition temperature was 360° C. Reactor pressure was 2 Torr.

[0078] Experiment: In this example, the VOCl3 pulse time was varied from 0.3 seconds to 3 seconds. The argon purge was for 30 seconds. The ammonia pulse was for 5 seconds. And the argon purge after the ammonia pulse was for 30 seconds. This experiment shows the self-limiting, saturation behavior of the VOCl3 precursor on various substrates such as aluminum oxide (AlO3), titanium nitride (TiN), silicon oxide (SiO2) and zirconium oxide (ZrO2). This behavior is indicative of an ALD process.

[0079] FIG. 1 shows the dependence of film thickness deposited by the VOCl and ammonia ALD process on the VOCl pulse time for this example.

[0080] Example 2

[0081] Conditions: Deposition temperature was 360° C. Reactor pressure was 2 Torr.

[0082] Experiment: In this experiment, the VOCl3 pulse time was 1 second. The argon purge was for 30 seconds. The ammonia pulse was varied from 0.5 seconds to 5 seconds, and the argon pulse after the ammonia pulse was for 30 seconds. This experiment shows the self-limiting, saturation behavior on various substrates such as aluminum oxide (Al2O3), titanium nitride (TiN), silicon oxide (SiO2), and zirconium oxide (ZrO2). The intensity is indicative of an ALD process.

[0083] FIG. 2 shows the dependence of film thickness deposited by the VOCl3 and ammonia ALD process on the ammonia pulse time for this example.

[0084] Example 3

[0085] Conditions: substrate temperature was 463° C. Reactor pressure was 2 Torr.

[0086] Experimental: In this experiment, the VOCl3 pulse was for 1 second. The argon purge was for 60 seconds. The ammonia pulse was for 5 seconds. And the argon purge after the ammonia was for 90 seconds. Approximately 100% conformality was obtained on the high aspect ratio wafers, indicative of an ALD process.

[0087] FIG. 3 shows a TEM cross-section of an example trench-patterned substrate having an aspect ratio of about 1 / 20 and a VN thin film deposited by VOCl3 and NH3 ALD processes.

[0088] result

[0089] Table 1 shows the compositions measured by Rutherford backscattering spectroscopy (RBS) of vanadium oxynitride and vanadium nitride films deposited by the VOCl3 and NH3 processes at different substrate temperatures. Near-stoichiometric vanadium nitride films at a wafer temperature of 500 °C were deposited without detectable chloride in the film. When an N2 plasma step was introduced after the VOCl3 / Ar / NH3 / Ar sequence, stoichiometric VN films with further reduction in oxygen content were deposited: 46 atomic (at) % vanadium and 46 atomic % oxygen.

[0090] [Table 1]

[0091] Table 2 shows the film resistivity of vanadium nitride on thermally oxidized silicon substrate for different deposition process sequences of the disclosed subject matter. The wafer temperature was 463° C. The ammonia flow rate was 300 sccm. The carrier gas flow rate through the VOCl3 bubbler was 50 sccm. The data shows that the introduction of N2 plasma results in a significant reduction in film resistivity compared to film treatment with hot hydrogen (no effect) and hydrogen plasma (higher resistivity).

[0092] [Table 2]

[0093] While the invention has been described and illustrated in some detail, it should be understood that this disclosure is made by way of example only, and that many changes in the conditions and sequence of steps may be made by those skilled in the art without departing from the spirit and scope of the invention.

Claims

1. The following steps: (i) contacting a substrate with vanadium oxytrichloride vapor in a deposition reactor; (ii) purging unreacted vanadium oxytrichloride with a first inert gas; (iii) contacting the substrate in the deposition reactor with a nitrogen-containing reactant; (iv) optionally purging any unreacted nitrogen-containing reactant with a second inert gas; and (v) optionally treating the substrate with a plasma; 1. A method for depositing a vanadium-containing film, comprising:

2. 2. The method of claim 1, wherein (i) said step of contacting said substrate with vanadium oxytrichloride vapor comprises pulsing vanadium oxytrichloride vapor for about 0.1 seconds to about 3 seconds.

3. 2. The method of claim 1, wherein (ii) said step of purging unreacted vanadium oxytrichloride with said first inert gas comprises a purge time of from about 1 second to about 90 seconds.

4. 2. The method of claim 1, wherein in step (iii), the nitrogen-containing reactant comprises one or more of ammonia, hydrazine, monoalkylhydrazine, and dialkylhydrazine.

5. The method of claim 1 , wherein in step (iii), the nitrogen-containing reactant comprises ammonia.

6. 2. The method of claim 1, wherein (iii) said step of contacting said substrate with said nitrogen-containing reactant comprises pulsing said nitrogen-containing reactant for about 0.5 seconds to about 5 seconds.

7. 2. The method of claim 1, wherein (iv) said step of optionally purging any unreacted nitrogen-containing reactant with a second inert gas comprises a purge time of from about 15 seconds to about 90 seconds.

8. (v) the step of treating the substrate with a plasma to remove residual oxygen from the oxynitride film comprises treating the substrate with a plasma to remove residual oxygen from the oxynitride film by ... ２ ) plasma or hydrogen (H ２ 2. The method of claim 1, further comprising treating with a plasma.

9. The method of claim 1 , wherein the substrate comprises silicon oxide.

10. The method of claim 1 , wherein the substrate comprises aluminum oxide.

11. The method of claim 1 , wherein the substrate comprises titanium nitride.

12. The method of claim 1 , wherein the substrate comprises titanium oxide.

13. The method of claim 1 , wherein the substrate comprises zirconium oxide.

14. The method of claim 1 , wherein the substrate is heated to a temperature of about 300°C to about 600°C.

15. The method of claim 1 , wherein the deposition reactor is at a pressure of about 50 Torr or less.

16. The method of claim 1 , wherein the membrane has an aspect ratio of about 1 to about 60.

17. The method of claim 1 , wherein the film has a resistivity of about 150 to about 500 μΩ·cm.

18. The method of claim 1 , wherein the film comprises vanadium nitride.

19. The method of claim 1 , wherein the film comprises vanadium oxynitride.

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