Methods and Systems for Delivering Vanadium Compounds

Abstract

A method can include: disposing vanadium tetrachloride in a delivery container; delivering the vanadium tetrachloride to a reaction chamber that is in fluid communication with the delivery container; slowing the delivery of decomposition products of the vanadium tetrachloride to the reaction chamber; and / or applying the vanadium tetrachloride to a substrate disposed in the reaction chamber to form a layer including vanadium on the substrate.

Description

Technical Field

[0001] The present disclosure generally relates to methods and apparatus suitable for use in a vapor reactor system. More particularly, the present disclosure relates to methods, compounds, and systems that can be used to stabilize precursors to mitigate contamination in a vapor reactor system. Background Art

[0002] A precursor is a compound that can be used to form another material. For example, a precursor can be used in a vapor-phase reaction to form a thin film or layer of a material. Unfortunately, some precursors that may have desirable properties (such as a desirable vapor pressure at normal pressure and room temperature) and / or desirable reactivity (e.g., with a surface or another compound) may decompose into other compounds. In particular, some precursors may decompose to produce corrosive gases, which may corrode parts of the reactor system during processing and / or cause undesirable etching. Decomposition can shorten the shelf life of the precursor, complicate manufacturing, require additional purification steps, cause storage and / or transportation problems, and may limit the amount of the desired material available for reaction within the source container within the reactor system. Additionally, corrosion of reactor system parts can shorten the life of the reactor system and / or its parts and thus increase the cost of operating such equipment. Additionally, corrosion can cause reactor system etch products to incorporate into the deposited film and / or cause substrate shortening of the film etch, which in turn may result in a decrease in the quality and / or uniformity of such a film. Additionally, since the precursor decomposition rate generally increases with temperature, it hinders the ability to increase the precursor flux to the reaction chamber by heating the precursor.

[0003] Efforts to reduce the decomposition of precursors have led to precursors that produce films with undesirably high carbon content, may require undesirably high temperatures to obtain a desired flux rate, may result in chemical vapor deposition (CVD) of materials during desired atomic layer deposition (ALD), may lack desired control of the growth rate, and / or may exhibit relatively poor step coverage. Accordingly, improved methods, apparatus, and compositions for providing precursors for vapor-phase reactions are desired.

[0004] Any discussion set forth in this section, including discussions of problems and solutions, is included in this disclosure only to provide background for the disclosure. Such discussions should not be construed as an admission that any or all of the information is known at the time of this disclosure or otherwise constitutes prior art. Summary of the Invention

[0005] This summary of the invention introduces some concepts in a simplified form that will be further described in detail below. The purpose of this summary of the invention is not necessarily to identify key features or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter.

[0006] Various embodiments of the present disclosure relate to a method and system for slowing down the decomposition of a vanadium compound used as a precursor in a deposition process (e.g., atomic layer deposition) and / or stabilizing it, and / or slowing down the delivery of the decomposition products of the vanadium compound to a reaction chamber.

[0007] According to an exemplary embodiment of the present disclosure, the method may include setting vanadium tetrachloride in a delivery container; delivering the vanadium tetrachloride to a reaction chamber in fluid communication with the delivery container; slowing down the delivery of the decomposition products of the vanadium tetrachloride to the reaction chamber; and / or applying the vanadium tetrachloride to a substrate disposed in the reaction chamber to form a layer including vanadium on the substrate.

[0008] In various embodiments, slowing down the delivery of the decomposition products of vanadium tetrachloride, which may include vanadium trichloride and chlorine, may include slowing down the decomposition of vanadium tetrachloride within the delivery container. In various embodiments, slowing down the decomposition of vanadium tetrachloride within the delivery container may include supplying an excess of chlorine to the delivery container before delivering the vanadium tetrachloride to the reaction chamber. In various embodiments, slowing down the decomposition of vanadium tetrachloride within the delivery container may include transferring the vanadium tetrachloride and chlorine from the delivery container to a waste tank; and / or delivering fresh vanadium tetrachloride to the delivery container before delivering the vanadium tetrachloride to the reaction chamber. In various embodiments, slowing down the decomposition of vanadium tetrachloride within the delivery container may include removing chlorine from the delivery container. In various embodiments, removing chlorine from the delivery container may further include removing dissolved chlorine included in the components including vanadium tetrachloride from the delivery container. In various embodiments, slowing down the decomposition of vanadium tetrachloride within the delivery container may include periodically discharging one or more of the decomposition products out of the delivery container through an exhaust valve of the delivery container based on a timed discharge schedule.

[0009] In various embodiments, the delivery container may include a bottom recessed area, where the tip of an immersion tube may be disposed within the bottom recessed area. In various embodiments, fresh vanadium tetrachloride may be set into the delivery container from a bulk supply tank in fluid communication with the delivery container. In various embodiments, the method may further include slowing down the decomposition of the fresh vanadium tetrachloride within the bulk supply tank. In various embodiments, slowing down the decomposition of the fresh vanadium tetrachloride within the bulk supply tank may include supplying an excess of chlorine to the bulk supply tank. In various embodiments, slowing down the decomposition of the fresh vanadium tetrachloride within the bulk supply tank may include removing chlorine from the bulk supply tank. In various embodiments, removing chlorine from the bulk supply tank may further include removing dissolved chlorine included in the components including fresh vanadium tetrachloride from the bulk supply tank. In various embodiments, slowing down the decomposition of the fresh vanadium tetrachloride within the bulk supply tank may include periodically discharging one or more of the decomposition products out of the bulk supply tank through an exhaust valve of the bulk supply tank based on a timed discharge schedule.

[0010] In various embodiments, the method may further include monitoring the pressure within the delivery container. Slowing the decomposition of vanadium tetrachloride within the delivery container may include discharging one or more of the decomposition products from the delivery container through an exhaust valve of the delivery container in response to the pressure reaching or exceeding a pressure threshold level. In various embodiments, the method may further include monitoring the pressure within the bulk supply tank. Slowing the decomposition of fresh vanadium tetrachloride within the bulk supply tank may include discharging one or more of the decomposition products from the bulk supply tank through an exhaust valve of the bulk supply tank in response to the pressure reaching or exceeding a pressure threshold level.

[0011] In various embodiments, delivering vanadium tetrachloride to the reaction chamber may include flowing a composition comprising vanadium tetrachloride through a filter that removes chlorine gas included in the composition.

[0012] In various embodiments, the reactor system (and / or the chemical delivery system included therein) may include the components described herein to perform the methods and method steps discussed. In various embodiments, at least one of the reaction chamber and the delivery container comprises stainless steel. In various embodiments, the reactor system may further include a pressure monitor configured to monitor the pressure within at least one of the delivery container and the bulk supply tank fluidly coupled to the delivery container.

[0013] Referring to the accompanying drawings, these and other embodiments will become apparent to those skilled in the art from the following detailed description of certain embodiments. The present disclosure is not limited to any particular embodiment disclosed. BRIEF DESCRIPTION OF THE DRAWINGS

[0014] A more complete understanding of the embodiments of the present disclosure can be obtained by reference to the detailed description and the claims when considered in conjunction with the following illustrative drawings. In all of the drawings, elements with the same reference numerals are intended to be the same.

[0015] Figure 1 A schematic diagram of an exemplary reactor system in accordance with various embodiments of the present disclosure is illustrated.

[0016] Figure 2 A schematic diagram of an exemplary reactor system including a chemical delivery system in accordance with various embodiments of the present disclosure is illustrated.

[0017] Figure 3 A schematic diagram of another exemplary reactor system including a chemical delivery system in accordance with various embodiments of the present disclosure is illustrated.

[0018] Figure 4 A schematic diagram of yet another exemplary reactor system including a chemical delivery system in accordance with various embodiments of the present disclosure is illustrated.

[0019] Figure 5Illustrated is a container applicable to a chemical delivery system according to various embodiments of the present disclosure.

[0020] Figure 6 Illustrated is a method of applying a vanadium compound to a substrate in a reaction chamber according to various embodiments of the present disclosure.

[0021] Figure 7 Illustrated is a method of slowing the delivery of decomposition products of a vanadium compound to a reaction chamber according to various embodiments of the present disclosure.

[0022] It should be understood that the elements in the drawings are shown for simplicity and clarity and are not necessarily drawn to scale. For example, the dimensions of some elements in the figures may be exaggerated relative to other elements to help improve the understanding of the illustrated embodiments of the present disclosure. Detailed Description

[0023] The following description of exemplary embodiments of methods, compositions, containers, devices, systems, and their uses provided is merely exemplary and for illustrative purposes only; the following description is not intended to limit the scope of the present disclosure or the claims. Additionally, the recitation of multiple embodiments having the described features is not intended to exclude other embodiments having additional features or other embodiments combining different combinations of the described features. Unless otherwise stated, the exemplary embodiments or their components may be combined or may be applied separately from each other.

[0024] As elaborated in more detail below, various embodiments of the present disclosure provide systems and methods to effect or facilitate the transport, storage, and / or supply of a composition and / or a vanadium compound to a (e.g., gaseous) reaction chamber of a reactor system. Exemplary systems and methods function to slow the undesired decomposition of the vanadium compound and / or slow the delivery of decomposition products of the vanadium compound to the reaction chamber. The methods, compositions, containers, devices, systems, and their uses described herein can be used in a variety of applications.

[0025] In the present disclosure, "gas" can include materials that are gases at normal temperature and pressure (NTP), vaporized solids, and / or vaporized liquids, and can consist of a single gas or a mixture of gases, depending on the context. Gases other than process gases (i.e., gases introduced without passing through a gas distribution component, other gas distribution devices, etc.) can be used, for example, to seal a reaction space, and can include sealing gases such as noble gases. In some cases, the term "precursor" can refer to a compound that participates in a chemical reaction to produce another compound, and particularly to a compound that constitutes the film matrix or the main backbone of the film; the term "reactant" can be used interchangeably with the term precursor. The term "inert gas" can refer to a gas that does not participate to a perceptible extent in a chemical reaction and / or does not become part of the film matrix. Exemplary inert gases include helium, argon, and / or any combination thereof. In some cases, the inert gas can include nitrogen and / or hydrogen.

[0026] As used herein, the term "substrate" can refer to any one or more underlying materials on which a device, circuit, or film can be formed or on which a device, circuit, or film can be formed. The substrate can include bulk materials such as silicon (e.g., single-crystalline silicon), other Group IV materials such as germanium, or other semiconductor materials such as Group II-VI or Group III-V semiconductor materials, and can include one or more layers above or below the bulk material. Additionally, the substrate can include various features such as recesses, protrusions, etc. formed within a layer of the substrate or on at least a portion of a layer of the substrate. As an example, the substrate can include a bulk semiconductor material and an insulating or dielectric material layer above at least a portion of the bulk semiconductor material.

[0027] As used herein, the terms "film" and / or "layer" can refer to any continuous or discontinuous structure and material, such as materials deposited by the methods disclosed herein. For example, a film and / or layer can include two-dimensional materials, three-dimensional materials, nanoparticles, or even partial or complete molecular layers or partial or complete atomic layers or clusters of atoms and / or molecules. A film or layer can include a material or layer having pinholes and can be at least partially continuous.

[0028] As used herein, "structure" can be or include a substrate as described herein. The structure can include one or more layers above the substrate, such as one or more layers formed according to the methods described herein. Devices and device parts can be or include a structure or be formed using a structure.

[0029] The term "cyclic deposition process" or "cyclic deposition technology" may refer to a process of sequentially introducing precursors (and / or reactants) into a reaction chamber to deposit a layer on a substrate, and includes processing techniques such as atomic layer deposition (ALD), cyclic chemical vapor deposition (cyclic CVD), and hybrid cyclic deposition processes that include ALD components and cyclic CVD components.

[0030] The term "atomic layer deposition" may refer to a vapor deposition process in which deposition cycles are performed in a process chamber, such as a plurality of successive deposition cycles. As used herein, when performed with alternating pulses of (one or more) precursors / (one or more) reactive gases and (one or more) purge (e.g., inert carrier) gases, the term atomic layer deposition is also intended to include processes referred to by related terms such as chemical vapor atomic layer deposition, atomic layer epitaxy (ALE), molecular beam epitaxy (MBE), gas source MBE, organometallic MBE, and chemical beam epitaxy.

[0031] As used herein, "vanadium compound" includes compounds that can be represented by chemical formulas containing vanadium. As used herein, "vanadium precursor" includes materials (e.g., evaporated liquids) in which the gas can or becomes gaseous and can be represented by a chemical formula containing vanadium.

[0032] As used herein, "vanadium halide precursor" includes materials in which the gas or can become gaseous and can be represented by a chemical formula containing vanadium and one or more of halogens such as fluorine (F), chlorine (Cl), bromine (Br), and iodine (I).

[0033] As used herein, a "vanadium layer" or "layer containing vanadium" may be a layer of material that can be represented by a chemical formula containing vanadium. The vanadium layer may include one or more of oxygen, nitrogen, sulfur, and carbon, e.g., a vanadium carbonitride layer. For example, the vanadium layer may be a binary compound containing vanadium and another element such as C, N, O, S, or a ternary compound including vanadium and two or more other elements, such as two or more of C, N, O, S. The chemical formula of the vanadium layer material may be represented by M b X y Z a where M is vanadium, and X may be C, N, O, S, and Z may be C, N, O, S, and where b is greater than 0 and less than 1, and y and a may range from 0 to less than 1.

[0034] In addition, in the present disclosure, any two numbers of a variable can form a viable range of the variable, and any indicated range can include or exclude endpoints. Additionally, any value of an indicated variable (whether or not they are indicated with "about") can refer to an exact value or an approximate value and includes equivalents, and can refer to an average, a median, a representative value, a majority, etc. Further, in the present disclosure, in some embodiments, the terms "comprising", "consisting of", and "having" independently refer to "typically or broadly including", "containing", "substantially consisting of", or "consisting of". Moreover, whether or not explicitly stated, the components and compounds described herein can contain, substantially consist of, or consist of the compounds and reagents described herein. In the present disclosure, in some embodiments, the meaning of any definition does not necessarily exclude the ordinary and customary meanings.

[0035] Reactor systems for ALD, CVD, etc. can be used for a variety of applications, including depositing and etching materials on a substrate surface. In various embodiments, reactor system 50 can include a reaction chamber 4, a susceptor 6 to hold a substrate 30 during processing, a fluid distribution system 8 (e.g., a showerhead) to distribute one or more reactants onto the surface of substrate 30, a chemical delivery system 10 to deliver one or more reactants from a reactant source, and / or to deliver a carrier and / or purge gas from such a source to reaction chamber 4, fluidly coupled to reaction chamber 4 via one or more lines (e.g., line 16), and a valve or controller (e.g., valve 22). Reactant gas or other material from a reactant source in chemical delivery system 10 can be applied to substrate 30 in reaction chamber 4. Purge gas from a purge gas source in chemical delivery system 10 can flow into and through reaction chamber 4 to remove any excess reactants or other undesired materials from reaction chamber 4. System 50 can also include a vacuum source 28 fluidly coupled to reaction chamber 4, which can be configured to suction or pump reactants, purge gas, or other materials out of reaction chamber 4.

[0036] Figure 2-4 Illustrated are reactor systems 100A - 100C (examples of reactor system 50) in accordance with various embodiments of the present disclosure. Systems 100A - 100C can be used to perform the methods described herein and / or to form the structures or device portions described herein.

[0037] In various embodiments, a reactor system (e.g., reactor systems 100A - 100C) can include a chemical delivery system (e.g., Figure 2 and Figure 3 chemical delivery system 200A as shown in Figure 4The chemical delivery system 200B) and reaction chamber (e.g., reaction chamber 150) shown in [Figure]. The chemical delivery system can be fluidly coupled to the reaction chamber such that the chemical delivery system can transfer or deliver one or more gases, precursors, reactants, etc. and / or purge gas or carrier gas to the reaction chamber. The reaction chamber in the reactor system can be any suitable reaction chamber, such as an ALD or CVD reaction chamber.

[0038] In various embodiments, the chemical delivery system can include a delivery container (e.g., delivery container 250), a bulk supply tank (e.g., bulk supply tank 220), a waste tank (e.g., waste tank 262), a gas source (e.g., gas sources 205 and / or 207), an evacuation system (e.g., evacuation system(s) 210), a pressure monitor (e.g., pressure monitor(s) 295), and / or a controller (e.g., controller 230). The components of the chemical delivery system can be arranged and coupled to each other in any suitable configuration. In various embodiments, the chemical delivery system can include one or more of each of these components (e.g., one or more delivery containers, bulk supply tanks, waste tanks, evacuation systems, etc.).

[0039] In various embodiments, the controller can be included within or external to the chemical delivery system. The controller can communicate electronically with one or more of the components of the chemical delivery system, and / or each component can communicate electronically with a corresponding controller. The controller can include a processor and / or a non-transitory, tangible, computer-readable medium to communicate with the processor, the processor having instructions stored thereon that, upon execution of the instructions by the processor, cause the processor to perform certain operations, such as causing the evacuation system to evacuate fluid from a tank or container at a certain rate, in a certain mode, and / or at a certain time, delivering or transferring fluid between tanks or containers in the chemical delivery system, and / or delivering or transferring fluid to the reaction chamber.

[0040] The controller may include electronic circuitry and software to selectively operate valves, manifolds, heaters, pumps, and other components included in a chemical delivery system and / or a reactor system. Such circuitry and components operate to introduce precursors, reactants, and purge gases from corresponding sources. As an example, the controller may be configured to control the flow of ingredients or vanadium compounds into, out of, and / or between a delivery vessel, a bulk supply tank, a waste tank, and / or a reaction chamber. The controller may control the timing of gas pulse sequences, the temperature of a substrate and / or reaction chamber, the pressure within the reaction chamber, and various other operations to provide proper operation of the chemical delivery system and / or reactor system. The controller may include control software to electrically or pneumatically control valves, thereby controlling the flow of precursors, reactants, and purge gases into, out of, and / or between a delivery vessel, a bulk supply tank, a waste tank, and / or a reaction chamber. The controller may include modules, such as software or hardware components (e.g., FPGA or ASIC), that perform certain tasks. The modules may advantageously be configured to reside on an addressable storage medium of the control system and be configured to execute one or more processes.

[0041] In various embodiments, a delivery vessel (e.g., delivery vessel 250) of a chemical delivery system may be used to transfer or deliver one or more gases, precursors, reactants, etc. and / or a purge or carrier gas to a reaction chamber. A gas source (e.g., gas source 205) may transfer such gases, precursors, reactants, etc. to the delivery vessel. The delivery vessel may be fluidly coupled to the reaction chamber.

[0042] In various embodiments, a bulk supply tank (e.g., bulk supply tank 220) of a chemical delivery system may be used to transfer or deliver one or more gases, precursors, reactants, etc. and / or a purge or carrier gas to a delivery vessel. For example, the bulk supply tank may include fresh precursors, reactants, etc. to be supplied to the delivery vessel to replenish and / or replace precursors, reactions, etc. within the delivery vessel. A gas source (e.g., gas source 207) may supply such gases, precursors, reactants, etc. to the bulk supply tank. The bulk supply tank may be fluidly coupled to the delivery vessel.

[0043] An exhaust system (e.g., exhaust system(s) 210) can be coupled to a delivery container to exhaust or pump out excess or undesirable fluid (i.e., liquid or gas) from the delivery container. Similarly, the exhaust system can be coupled to a bulk supply tank to exhaust or pump out excess or undesirable fluid (i.e., liquid or gas) from the bulk supply tank. Similarly, the exhaust system can be coupled to a waste tank to exhaust or pump out excess or undesirable fluid (i.e., liquid or gas) from the waste tank. The delivery container, bulk supply tank, and / or waste tank can include an exhaust valve through which the exhausted fluid can flow. The exhaust system can include a pump 214 to pump fluid from the delivery container, bulk supply tank, and / or waste tank, and / or a scrubber 212 to remove any undesirable particulates, contaminants, etc. from the exhausted fluid. In various embodiments, the exhaust system can be coupled to each tank or container within a chemical delivery system (e.g., in chemical delivery system 200A, separate exhaust systems 210 are coupled to each of delivery container 250, bulk supply tank 220, and waste tank 262). In various embodiments, the delivery container, bulk supply tank, and / or waste tank can be coupled to a single exhaust system that is used to pump fluid from the delivery container, bulk supply tank, and / or waste tank (e.g., exhaust system 210 shared between bulk supply tank 220 and waste tank 262 in chemical delivery system 200B).

[0044] In various embodiments, a pressure monitor can be coupled to each tank or container within a chemical delivery system (e.g., in chemical delivery systems 200A and 200B, each of delivery container 250, bulk supply tank 220, and waste tank 262 is coupled to a pressure monitor 295). Each tank or container within the chemical delivery system can be coupled to a respective pressure monitor, or one or more tanks or containers can be coupled to a common pressure monitor. The pressure monitor can be configured to measure and / or monitor the pressure within the respective tank(s) or container(s). If, for example, the pressure within a tank or container reaches or exceeds a threshold pressure value, excess fluid within such a tank or container can be exhausted through the respective exhaust system (which can be facilitated or commanded by a controller (e.g., controller 230)).

[0045] Components of the reactor system (and / or the chemical delivery system included therein) can include any suitable material, such as stainless steel.

[0046] A chemical delivery system according to various embodiments of the present disclosure can be configured to slow down or prevent the decomposition of precursors, reactants, etc. to be delivered to a reaction chamber. Similarly, such a chemical delivery system can be configured to slow down or prevent decomposition products from precursors, reactants, etc. from being delivered from the chemical delivery system to the reaction chamber.

[0047] The vanadium compounds used within the reactor system according to various embodiments of the present disclosure can be used to form vanadium layers, which are suitable for metal-oxide semiconductor (MOS) applications (e.g., as work function layers and / or bipolar or flatband shifters), such as in the formation of complementary MOS (CMOS) devices, to be used as an etch stop layer, and / or as a barrier or liner layer (e.g., in MEOL and BEOL processes). For example, the vanadium layer can be used in the formation of logic devices, dynamic random access memories (DRAMs), three-dimensional NAND devices, as the p-metal layer gate of a logic device, as the p-bipolar layer of a logic device, etc. However, unless otherwise stated, the present disclosure is not necessarily limited to such examples.

[0048] Referring Figure 6 to method 600 shown in Figure 2-4 , to form a vanadium layer on a substrate, the vanadium compound can be disposed in a delivery container (e.g., delivery container 250) (step 602). The vanadium compound can be delivered or transferred to a reaction chamber (e.g., reaction chamber 150) (step 604) and applied to the substrate in the reaction chamber (step 608).

[0049] In various embodiments, applying the vanadium compound to the substrate in the reaction chamber (step 608) can be accomplished using a cyclic deposition process that deposits a layer comprising vanadium onto the surface of the substrate. The cyclic deposition process can comprise (e.g., separately and / or sequentially) providing a vanadium precursor to the reaction chamber and providing a reactant to the reaction chamber. During step 608, a vanadium layer is deposited onto the surface of the substrate using the cyclic deposition process. As described above, the cyclic deposition process can comprise cyclic CVD, ALD, or a hybrid cyclic CVD / ALD process. For example, in some embodiments, the growth rate of a particular ALD process may be low compared to a CVD process. One scenario for increasing the growth rate can be to operate at a deposition temperature that is higher than the temperature typically employed in an ALD process, resulting in some portions of a chemical vapor deposition process, but still utilizing the sequential introduction of reactants. Such a process can be referred to as cyclic CVD. In some embodiments, the cyclic CVD process can include introducing two or more reactants into the reaction chamber, where there may be an overlapping time period between the two or more reactants present in the reaction chamber, resulting in a deposited ALD component and a deposited CVD component. This is referred to as a hybrid process. According to other examples, the cyclic deposition process can include a continuous flow of one reactant / precursor while a second reactant is pulsed periodically into the reaction chamber.

[0050] The thickness of the vanadium layer can vary according to the application. As an example, the thickness of the vanadium layer can be less than 5 nm or about 0.1 nm to about 10 nm, or about 0.1 nm to about 5 nm, or about 0.2 nm to about 5 nm, or about 0.3 nm to about 3 nm, or about 0.3 nm to about 1 nm. When used to replace a layer that may contain aluminum instead of vanadium, the vanadium layer can be relatively thin, which may be desirable for many applications, including work function and / or voltage threshold adjustment layers. In some cases, the thickness of the vanadium layer can be greater than 2 nm, for example, when the vanadium layer is used as a barrier layer or liner. The vanadium layer can form a continuous film - for example, with a thickness of <5 nm, <4 nm, <3 nm, <2 nm, <1.5 nm, <1.2 nm, <1.0 nm, or <0.9 nm. The vanadium layer can be relatively smooth, with relatively low grain boundary formation. In some cases, the vanadium layer can be amorphous, with a relatively low columnar crystal structure (compared to TiN). At thicknesses less than 10 nm, the RMS roughness of an exemplary vanadium layer can be <1.0 nm, <0.7 nm, <0.5 nm, <0.4 nm, <0.35 nm, or <0.3 nm.

[0051] Vanadium compounds (e.g., vanadium precursors) such as vanadium tetrachloride used in processes (such as method 600) in a reactor system according to various embodiments of the present disclosure can be relatively unstable and decompose at room temperature to, for example, vanadium trichloride and chlorine gas (Cl2). Some processes can include heating the precursor to facilitate and / or speed up the process. Heating the vanadium compound can cause an accelerated decomposition. Vanadium trichloride is a solid at room temperature, which can contaminate or clog containers, tanks, or pipelines that include vanadium tetrachloride. For example, vanadium trichloride can accumulate in the delivery container or bulk supply tank or in the pipelines therebetween or leading to the reactor. Additionally, chlorine gas in the reaction chamber can cause etching of the target layer (e.g., vanadium layer) on the substrate, which can reduce the cyclic growth of the vanadium layer and / or result in spatial non-uniformity or lack of step coverage along the layer.

[0052] Accordingly, systems and methods according to various embodiments of the present disclosure can include slowing or preventing the delivery of decomposition products of the vanadium compound to the reaction chamber (step 606). To this end, for example, the decomposition of vanadium tetrachloride can be slowed or prevented (e.g., in the tanks, containers, and / or pipelines of a chemical delivery system or reactor system). Figure 7 Method 700 in shows various steps to slow or prevent the decomposition of a vanadium compound (e.g., vanadium tetrachloride) and / or slow or prevent the delivery of vanadium compound decomposition products to the reaction chamber. The steps of method 700 can be performed in any suitable order, mode, and / or combination. Method 600 and method 700 can be carried out by a reactor system and a chemical delivery system according to various embodiments of the present disclosure.

[0053] In various embodiments, excess chlorine gas can be supplied to a canister or vessel (e.g., delivery vessel 250 and / or bulk supply canister 220) that includes a vanadium compound (step 702). For example, delivery vessel 250 can include vanadium tetrachloride, and chlorine gas can be supplied from gas source 205 to delivery vessel 250. As a similar example, bulk supply canister 220 can include vanadium tetrachloride, and chlorine gas can be supplied from gas source 207 to bulk supply canister 220. Because chlorine gas is a decomposition product of vanadium chloride, according to Le Chatelier’s principle, adding chlorine gas to an environment where vanadium tetrachloride might decompose can slow or prevent such decomposition. In other words, adding the product (chlorine gas) of the reaction (decomposition of vanadium tetrachloride into chlorine gas and vanadium trichloride) drives the reaction equilibrium towards the reactant side of the chemical reaction (vanadium tetrachloride), thereby slowing or preventing the production of further products (chlorine gas and vanadium trichloride) (i.e., slowing or preventing the decomposition of vanadium tetrachloride).

[0054] Chlorine gas can be supplied from a gas source to the delivery vessel or the bulk supply canister. For example, chlorine gas can be supplied from gas source 205 to delivery vessel 250, and / or chlorine gas can be supplied from gas source 207 to bulk supply canister 220. In various embodiments, the chlorine gas supplied to the canister or vessel in the chemical delivery system can be supplied from a common gas source.

[0055] In various embodiments, implemented on a similar principle, the carrier gas that flows through the delivery vessel to deliver the vanadium compound to the reaction chamber can include chlorine gas. Similar to that discussed above, the presence of chlorine gas in the carrier gas can drive the decomposition reaction of the vanadium compound towards the reactant side of the chemical equation (e.g., vanadium tetrachloride, preventing or slowing its decomposition). Although the presence of chlorine gas in the carrier gas might cause etching in the reaction chamber and / or on the substrate, by adjusting the amount of chlorine gas in the carrier gas (again, this will slow the decomposition of the vanadium compound, which otherwise might form an unpredictable amount of chlorine gas), the amount of etching can be made more predictable, and thus, the process conditions and cycles can be configured to compensate for such etching. Because of the unknown amount of chlorine gas and the resulting unknown etching, the unpredictable chlorine gas from the decomposition of the vanadium compound can make it difficult to compensate for any resulting etching.

[0056] In various embodiments, the contents of the delivery container can be removed and replaced by fresh precursors, reactors, or other compounds. For example, periodically, just before the start of a processing cycle and / or at any other appropriate time, fresh vanadium compounds can be supplied to the delivery container to be sent to the reaction chamber. To this end, the vanadium compounds in the delivery container (e.g., delivery container 250) and any decomposition products from the decomposition of the vanadium compounds (e.g., chlorine gas and / or vanadium trichloride) can be transferred from the delivery container (step 704). The vanadium compounds and decomposition products removed from the delivery container can be transferred to a waste tank (e.g., waste tank 262) for disposal. The contents of the waste tank can be transferred or pumped out, for example, by a pump 214 (e.g., of the exhaust system 210) for ultimate disposal. Correspondingly, fresh vanadium compounds (not yet decomposed, and / or having undergone a little decomposition) can be supplied to the delivery container from another tank or container (e.g., from the bulk supply tank 220) (step 706). In various embodiments, in response to the delivery container receiving fresh vanadium compounds, the vanadium compounds can be transferred from the delivery container to the reaction chamber (e.g., step 604) for application to a substrate (e.g., step 608). The delivery container can receive fresh vanadium compounds (after the old vanadium compounds and decomposition products have been removed from it) periodically, after a predetermined duration, before each processing cycle in the reaction chamber, and / or at any other appropriate time.

[0057] Similarly, in various embodiments, vanadium compounds and their decomposition products can be removed from the bulk supply tank and placed in the waste tank (e.g., using the chemical delivery system 200B, where the bulk supply tank 220 is coupled to the waste tank 262). Correspondingly, fresh vanadium compounds can be placed in the bulk supply tank.

[0058] To ensure that old vanadium compounds and their decomposition products can be thoroughly removed from the tank or container, the tank or container can include a recessed area at the bottom where the end of an immersion tube can be disposed. For example, as Figure 5 shown, the container 550 (which can be an example of a delivery container and / or a bulk supply tank) can include a recessed bottom portion 552. The immersion tube 570 can be disposed in the container 550, and the compounds in the container 550 can be removed through the immersion tube 570 (e.g., to be replaced by fresh compounds). The end of the immersion tube 570 can be disposed in the recessed bottom portion 552 of the container 550, and the compounds can be suctioned out of the container 550 through the end of the immersion tube 570. Such an orientation of the immersion tube within the recessed bottom portion of the container can facilitate better removal (i.e., most or all) of the old compounds in the container to be replaced by fresh compounds (e.g., vanadium compounds).

[0059] In various embodiments, chlorine gas accumulating in a tank or container from the decomposition of a vanadium compound can be removed (step 708). For example, chlorine gas accumulating in the delivery container 250 from the decomposition of vanadium tetrachloride can be pumped out via the pump 214. As another example, chlorine gas accumulating in the bulk supply tank 220 from the decomposition of vanadium tetrachloride can be pumped out via the pump 214. Chlorine gas removed from the delivery container and the bulk supply tank can be removed via the same or different pumps. Additionally, chlorine gas that has dissolved in the vanadium tetrachloride (or in a component including vanadium tetrachloride) within the tank or container can also be removed by continuing to pump and / or applying a vacuum pressure within the tank or container. Removing chlorine gas from the delivery container can, for example, reduce the chance of chlorine gas transfer to the reaction chamber (e.g., during the transfer of the vanadium compound to the reaction chamber). In various embodiments, in response to chlorine gas being removed from the delivery container, vanadium tetrachloride can be transferred from the delivery container to the reaction chamber (e.g., step 604) for application to a substrate (e.g., step 608).

[0060] In various embodiments, as discussed herein, a tank or container in a chemical delivery system can be coupled to a pressure monitor (e.g., pressure monitor 295). The pressure monitor can measure and / or monitor the pressure within the corresponding tank or container (e.g., within the bulk supply tank 220 and / or the delivery container 250) (step 710). In response to the pressure therein reaching a certain level (e.g., reaching or exceeding a threshold pressure level), the chemical delivery system and / or components therein can act to relieve such pressure. For example, in response to the pressure monitor detecting that the pressure level in the corresponding tank or container has reached or exceeded the threshold pressure level, an alarm or other notification can be transmitted to take action, or excess chlorine gas causing the pressure can be pumped or discharged from such a container (step 712). In various embodiments, the pumping or discharging of chlorine gas occurs for a predetermined amount of time until the corresponding pressure monitor determines that the pressure within the corresponding tank or container is at a certain pressure level or below, or according to any other appropriate process or parameter.

[0061] In various embodiments, instead of or in addition to a pressure monitor being attached to the delivery container or bulk supply tank, the delivery container or bulk supply tank can include a bleed valve. The bleed valve can be configured to remain at least partially closed (e.g., closed under spring tension). In response to the pressure within the corresponding container or tank reaching a certain level, the bleed valve can open to vent chlorine gas out of the container or tank (step 712), thereby relieving the pressure. That is, the tension holding the bleed valve in the at least partially closed position can be overcome at a certain pressure level within the container or tank such that the bleed valve (further) opens to vent the chlorine gas that caused the pressure level. In various embodiments, the bleed valve can be electronically controlled (e.g., by controller 230) and can open (further) periodically, at certain time intervals, for certain durations in response to the measured pressure reaching or exceeding a certain level and / or according to any other suitable process or parameter to vent gas out of the corresponding container or tank.

[0062] In various embodiments, the fluid (e.g., gas) vented from a container or tank in a chemical delivery system can pass through a scrubber (e.g., (a) scrubber(s) 212). The scrubber can remove any undesirable (e.g., toxic) particulates, compounds, chemicals, etc.

[0063] In various embodiments, the vanadium compound transferred from a delivery container (e.g., delivery container 250) to a reaction chamber (e.g., reaction chamber 150) can pass through a filter (e.g., filter 110). Such a filter can be configured to remove any undesirable materials or compounds from the vanadium compound and carrier fluid mixture. For example, the filter can remove particulates, chlorine gas (e.g., potentially from vanadium compound decomposition) or other contaminants that may have an undesirable effect during substrate processing. In various embodiments, the filter can be configured to remove chlorine gas without removing vanadium halide compounds such as vanadium tetrachloride.

[0064] As discussed, the steps of method 700 can be implemented in any combination in any order to slow down or prevent the decomposition of the vanadium compound (e.g., vanadium tetrachloride) and / or slow down or prevent the delivery of vanadium compound decomposition products (e.g., chlorine gas) to the reaction chamber. For example, for instance, after removing the old vanadium compound and its decomposition products from the delivery container (step 704), fresh vanadium compound can be transferred to the delivery container (step 706). Then, excess chlorine gas can be delivered to the delivery container (step 702) to slow down the decomposition of the fresh vanadium compound (in accordance with Le Chatelier's principle discussed herein). Then, the chlorine gas in the delivery container can be removed therefrom (step 708). Finally, the vanadium compound can be delivered from the delivery chamber to the reaction chamber (step 604) to be applied to the substrate (step 608).

[0065] After the vanadium compound has been applied to the substrate and / or any other application is complete, the fluid remaining in the reaction chamber (e.g., unreacted vanadium compound or vanadium precursor, excess reactant, by-product, inert gas, carrier gas, etc.) can be purged from the reaction chamber. For example, a purge gas can be applied to the reaction chamber 150 to remove such materials and compounds, which can be pumped out by a pump 114 (e.g., Figure 1 an example of the vacuum pump 28 in

[0066] Methods and systems configured to slow down the decomposition of the vanadium compound and / or slow down the delivery of the decomposition products of the vanadium compound to the reaction chamber can facilitate more desirable processing conditions for substrate processing. Thus, substrates can be processed to obtain more predictable and desirable results (e.g., uniform layer deposition, a certain amount of etching, etc.).

[0067] The various embodiments described above do not limit the scope of the present disclosure because these embodiments are merely examples. Any equivalent embodiments are intended to be within the scope of the present disclosure. Indeed, various modifications of the present disclosure, such as alternative useful combinations of the described elements, can become 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, comprising: delivering vanadium tetrachloride as a gas from a large-capacity supply tank to a delivery container; after delivering the vanadium tetrachloride to the delivery container, adding an excess of chlorine gas to the delivery container, thereby slowing the decomposition of the vanadium tetrachloride into decomposition products of the vanadium tetrachloride; delivering the vanadium tetrachloride from the delivery container to a reaction chamber in fluid communication with the delivery container; and applying the vanadium tetrachloride to a substrate disposed in the reaction chamber to form a layer comprising vanadium on the substrate.

2. The method according to claim 1, further comprising transferring the vanadium tetrachloride and the chlorine gas from the delivery container to a waste tank; and delivering fresh vanadium tetrachloride to the delivery container before delivering the vanadium tetrachloride to the reaction chamber.

3. The method according to claim 2, wherein the delivery container includes a bottom recessed area, and a tip of an immersion tube is disposed within the bottom recessed area.

4. The method according to claim 2, wherein the fresh vanadium tetrachloride is set to the delivery container from a large-capacity supply tank in fluid communication with the delivery container.

5. The method according to claim 4, further comprising slowing the decomposition of the fresh vanadium tetrachloride within the large-capacity supply tank.

6. The method according to claim 5, wherein slowing the decomposition of the fresh vanadium tetrachloride within the large-capacity supply tank includes supplying an excess of chlorine gas to the large-capacity supply tank.

7. The method according to claim 5, wherein slowing the decomposition of the fresh vanadium tetrachloride within the large-capacity supply tank includes removing the chlorine gas from the large-capacity supply tank.

8. The method according to claim 7, wherein removing the chlorine gas from the large-capacity supply tank further includes removing dissolved chlorine gas included in a component including the fresh vanadium tetrachloride from the large-capacity supply tank.

9. The method according to claim 1, further comprising removing the chlorine gas from the delivery container.

10. The method according to claim 9, wherein removing the chlorine gas from the delivery container further includes removing dissolved chlorine gas included in a component including the vanadium tetrachloride from the delivery container.

11. The method according to claim 1, further comprising: monitoring the pressure within the delivery container; and [[ID=ID=18]]in response to the pressure reaching or exceeding a pressure threshold level, discharging one or more of the decomposition products from the delivery container through an exhaust valve of the delivery container.

12. The method according to claim 1, further comprising periodically discharging one or more of the decomposition products from the delivery container through an exhaust valve of the delivery container based on a timed discharge schedule.

13. The method according to claim 1, wherein delivering the vanadium tetrachloride to the reaction chamber includes flowing a component including the vanadium tetrachloride through a filter that removes chlorine gas included in the component. 1 The method according to claim 5, further comprising: Monitor the pressure within the large-capacity supply tank, wherein slowing the decomposition of the fresh vanadium tetrachloride within the large-capacity supply tank includes, in response to the pressure reaching or exceeding a pressure threshold level, discharging one or more of the decomposition products out of the large-capacity supply tank through an exhaust valve of the large-capacity supply tank.

15. The method according to claim 5, wherein slowing the decomposition of the fresh vanadium tetrachloride within the large-capacity supply tank includes periodically discharging one or more of the decomposition products out of the large-capacity supply tank through an exhaust valve of the large-capacity supply tank based on a timed discharge schedule.

16. A reactor system configured to perform the method according to claim 1.

17. The reactor system according to claim 16, wherein at least one of the reaction chamber and the delivery container comprises stainless steel.

18. The reactor system according to claim 16, further comprising a pressure monitor configured to monitor the pressure within at least one of the delivery container and a large-capacity supply tank fluidly coupled to the delivery container.

Images