Method of forming oxide material

Abstract

Described herein are methods and systems for forming oxides comprising alkaline earth metals and optionally transition metals. Suitable alkaline earth metals include strontium. Suitable transition metals include niobium.

Description

Field of the Invention

[0001] This disclosure pertains to the field of forming oxide materials useful in integrated circuit fabrication. The oxide materials can include one or more of alkaline earth metals and transition metals. Background Art

[0002] In integrated circuit fabrication, there is a search for dielectrics with a high dielectric constant, such as for applications in MOSFET gate dielectrics and capacitors. To advance integrated circuit technology to higher operating speeds, dielectrics with a higher dielectric constant but still a low defect rate are needed. A low defect rate is desirable because it ideally reduces the parasitic current in devices containing the dielectric. Thus, there is a need for dielectrics with a high dielectric constant and a low defect rate. Summary of the Invention

[0003] Embodiments of this disclosure can address one or more of the above needs.

[0004] Described herein is a method of forming a layer comprising an alkaline earth metal and oxygen, the method comprising: providing a substrate to a reaction chamber; performing a plurality of alkaline earth metal oxide deposition cycles, wherein an alkaline earth metal oxide deposition cycle from the plurality of alkaline earth metal oxide deposition cycles comprises: one or more alkaline earth metal carbonate deposition cycles to form an alkaline earth metal carbonate, and an oxidizer pulse, which comprises exposing the substrate to an oxidizer to convert the alkaline earth metal carbonate film to an alkaline earth metal oxide; wherein an alkaline earth metal carbonate deposition cycle from the one or more alkaline earth metal carbonate deposition cycles comprises: an alkaline earth metal precursor pulse, which comprises exposing the substrate to an alkaline earth metal precursor, the alkaline earth metal precursor comprising an alkaline earth metal, and a first reactant pulse, which comprises exposing the substrate to a first reactant.

[0005] The present disclosure also describes a method of forming a layer on a substrate, the layer comprising an alkaline earth metal, a transition metal, and oxygen, the method comprising: providing a substrate to a reaction chamber; performing a plurality of alkaline earth metal oxide deposition cycles, an alkaline earth metal oxide deposition cycle from the plurality of alkaline earth metal oxide deposition cycles comprising: one or more alkaline earth metal carbonate deposition cycles to form an alkaline earth metal carbonate, an oxidant pulse comprising exposing the substrate to an oxidant to convert the alkaline earth metal carbonate film to an alkaline earth metal oxide, and one or more transition metal oxide deposition cycles to form a transition metal oxide; wherein, an alkaline earth metal carbonate deposition cycle from the one or more alkaline earth metal carbonate deposition cycles comprises: an alkaline earth metal precursor pulse comprising exposing the substrate to an alkaline earth metal precursor, the alkaline earth metal precursor comprising an alkaline earth metal, and a first reactant pulse comprising exposing the substrate to a first reactant; wherein, a transition metal oxide deposition cycle from the one or more transition metal oxide deposition cycles comprises: a transition metal precursor pulse comprising exposing the substrate to a transition metal precursor, the transition metal precursor comprising a transition metal; and a second reactant pulse comprising exposing the substrate to a second reactant.

[0006] In some embodiments, the alkaline earth metal comprises strontium.

[0007] In some embodiments, the alkaline earth metal precursor comprises a compound having the general formula M(R n Cp) 2 wherein M is an alkaline earth metal, R is a C1 to C6 alkyl group, and n is an integer from at least 0 to at most 3.

[0008] In some embodiments, the transition metal precursor comprises niobium.

[0009] In some embodiments, the transition metal precursor comprises one or more alkylamido ligands.

[0010] In some embodiments, the transition metal precursor comprises one or more alkylimino ligands.

[0011] In some embodiments, the transition metal precursor comprises a heteroleptic precursor, the heteroleptic precursor comprising one or more alkylamido ligands and one or more alkylimino ligands.

[0012] In some embodiments, the transition metal precursor comprises tris(diethylamido)(tert-butylimido)niobium.

[0013] In some embodiments, the oxidant comprises an oxygen reactant selected from H 2 O, H 2 O 2 、O 2 、O 3 、oxygen ions, and oxygen radicals.

[0014] In some embodiments, the oxidant includes ozone.

[0015] In some embodiments, at least one of the first reactant and the second reactant includes a chalcogen element.

[0016] In some embodiments, at least one of the first reactant and the second reactant includes ozone.

[0017] In some embodiments, the first reactant pulse has a first duration, wherein the oxidant pulse has an oxidant pulse duration, and wherein the oxidant pulse duration is longer than the first duration.

[0018] In some embodiments, the oxidant includes O 3 , the first reactant includes O 3 , and the second reactant includes H 2 O or O 3 .

[0019] Also described herein is a system including a reaction chamber and a controller, the system being constructed and arranged to perform the methods as described herein.

[0020] In some embodiments, the system includes an alkaline earth metal carbonate reaction chamber and a transition metal reaction chamber, the alkaline earth metal reaction chamber being constructed and arranged to form an alkaline earth metal carbonate, and the transition metal reaction chamber being constructed and arranged to form a transition metal oxide.

[0021] Further described herein is a film including an alkaline earth metal, a transition metal, and oxygen formed by the methods described herein.

[0022] The present invention content is provided to introduce some concepts in a simplified form. These concepts are further described in detail in the following detailed description of the exemplary embodiments disclosed herein. The present invention content is not intended to identify the key features or essential features of the claimed subject matter, nor is it intended to be used to limit the scope of the claimed subject matter. BRIEF DESCRIPTION OF THE DRAWINGS

[0023] Figure 1 An embodiment of a method 100 for forming a layer is shown.

[0024] Figure 2 An embodiment of a method for forming an alkaline earth metal carbonate is illustrated.

[0025] Figure 3 An embodiment of a method 300 for forming a layer including an alkaline earth metal, a transition metal, and oxygen is shown.

[0026] Figure 4 An embodiment of a method for forming a transition metal oxide is shown.

[0027] Figure 5 An embodiment of system 500 as described herein is shown.

[0028] Figure 6 An embodiment of a pulse as described herein is shown.

[0029] Figure 7 An embodiment of system 700 as described herein is shown.

[0030] It should be understood that the elements in the figures 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 assist in improving understanding of the illustrated embodiments of the present disclosure. Detailed Description

[0031] Although certain embodiments and examples are disclosed below, those skilled in the art will understand that the invention extends beyond the specifically disclosed embodiments and / or uses of the invention and their obvious modifications and equivalents. Thus, it is intended that the scope of the disclosed invention not be limited by the specifically disclosed embodiments described below.

[0032] As used herein, the term "substrate" can refer to any one or more underlying materials, including any one or more underlying materials that can be modified or on which devices, circuits, or films can be formed. A "substrate" can be continuous or discontinuous; rigid or flexible; solid or porous; and combinations thereof. The substrate can be in any form, such as powder, plate, or workpiece. Plate-like substrates can include wafers of various shapes and sizes. The substrate can be made of semiconductor materials, including, for example, silicon, silicon germanium, silicon oxide, gallium arsenide, gallium nitride, and silicon carbide.

[0033] For example, substrates in powder form can be used in pharmaceutical manufacturing. Porous substrates can contain polymers. Examples of workpieces can include medical devices (such as stents and syringes), jewelry, tooling equipment, components for battery manufacturing (such as anodes, cathodes, or separators), or components of photovoltaic cells, etc.

[0034] A continuous substrate can extend beyond the boundaries of the processing chamber where the deposition process occurs. In some processes, the continuous substrate can be moved through the processing chamber so that the process continues until the end of the substrate is reached. The continuous substrate can be provided from a continuous substrate feeding system to allow the manufacture and output of the continuous substrate in any suitable form.

[0035] Non-limiting examples of continuous substrates can include sheets, non-woven membranes, rolls, foils, meshes, flexible materials, bundles of continuous filaments or fibers (such as ceramic fibers or polymer fibers). The continuous substrate can also include a carrier or sheet on which a discontinuous substrate is mounted.

[0036] The diagrams presented herein are not meant to be actual views of any specific material, structure, or device, but are merely idealized representations for describing embodiments of the present disclosure.

[0037] The specific embodiments shown and described are illustrative of the invention and its best mode and are not intended to limit the scope of these aspects and embodiments in any way. In fact, for the sake of brevity, conventional manufacturing, connection, preparation, and other functional aspects of the system may not be described in detail. Additionally, the connecting lines shown in the figures are intended to represent exemplary functional relationships and / or physical couplings between various elements. Many alternative or additional functional relationships or physical connections may exist in the actual system and / or may not exist in some embodiments.

[0038] It should be understood that the configurations and / or methods described herein are exemplary in nature and these specific embodiments or examples should not be considered limiting as many variations are possible. The specific routines or methods described herein may represent one or more of any number of processing strategies. Accordingly, the various acts shown may be performed in the order shown, in other orders, or in some cases, omitted.

[0039] The subject matter of the present disclosure includes all novel and non-obvious combinations and sub-combinations of various processes, systems, and configurations, as well as other features, functions, acts, and / or properties disclosed herein, and any and all equivalents thereof.

[0040] In the present disclosure, "gas" may include materials that are gases at normal temperature and pressure (NTP), evaporated solids, and / or evaporated liquids, and may consist of a single gas or a gas mixture as the case may be. Gases other than the process gas, i.e., gases that are not introduced through a gas distribution assembly, other gas distribution devices, etc., may be used, for example, to seal a reaction space and may include sealing gases such as noble gases. In some cases, the term "precursor" may refer to a compound that participates in a chemical reaction to produce another compound, particularly a compound that constitutes a film matrix or a film backbone; the term "reactant" may be used interchangeably with the term precursor. The term "inert gas" may refer to a gas that does not participate in a chemical reaction and / or does not become part of the film matrix to a perceptible extent. Exemplary inert gases include helium, argon, and any combination thereof. In some cases, the inert gas may include nitrogen and / or hydrogen.

[0041] 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 atomic and / or molecular clusters, or layers composed of isolated atoms and / or molecules. A film or layer can include a material or layer having pinholes, which can be continuous or not continuous.

[0042] The term "cyclic deposition process" or "cyclic deposition process" can refer to the sequential introduction of 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 an ALD component and a cyclic CVD component. In a preferred embodiment, the cyclic deposition process disclosed herein refers to an atomic layer deposition process.

[0043] The term "atomic layer deposition" can refer to a vapor deposition process in which deposition cycles (usually multiple consecutive deposition cycles) are carried out in a processing chamber. The term atomic layer deposition as used herein also means including processes designated 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 when carried out with alternating pulses of precursor / reactant gas and purge gas (such as an inert carrier gas).

[0044] Generally, for an ALD process, during each cycle, a precursor is introduced into the reaction chamber and chemisorbed onto the deposition surface (such as a substrate surface that can include previously deposited material from a previous ALD cycle or other materials), and a material is formed that does not readily react with additional precursor (i.e., a self-limiting reaction), such as approximately a monolayer or sub-monolayer material, or several monolayers of material, or multiple monolayers of material. Thereafter, in some cases, a reactant (such as another precursor or reaction gas) can subsequently be introduced into the processing chamber for converting the chemisorbed precursor into the desired material on the deposition surface. The reactant is capable of further reacting with the precursor. During one or more cycles, for example, during each step of each cycle, a purge step can be utilized to remove any excess precursor and / or any excess reactant and / or reaction by-products from the reaction chamber. Note that as used herein, an ALD process does not necessarily consist of a series of self-limiting surface reactions.

[0045] Throughout this disclosure, the following abbreviations are used: Cp represents cyclopentadienyl, and iPr represents isopropyl.

[0046] Reference Figure 1, embodiments of method 100 for forming a layer are described herein. The layer may comprise an alkaline earth metal. In some embodiments, the layer may further comprise oxygen. For example, the layer may include an alkaline earth metal oxide. In some embodiments, the layer consists essentially of an alkaline earth metal oxide. According to Figure 1 the method of the embodiment includes step 111 of providing a substrate to a reaction chamber. The method further includes performing a plurality of alkaline earth metal oxide deposition cycles 115. The alkaline earth metal oxide deposition cycles from the plurality of alkaline earth metal oxide deposition cycles 115 include one or more alkaline earth metal carbonate deposition cycles 112 to form an alkaline earth metal carbonate. The alkaline earth metal carbonate can be formed, for example, by using a metal-organic or organometallic alkaline earth metal precursor and at least partially combusting the ligand of the precursor using an oxygen reactant such as ozone. The alkaline earth metal oxide deposition cycles from the plurality of alkaline earth metal oxide deposition cycles 115 further include an oxidant pulse 113, which includes exposing the substrate to an oxidant to convert the alkaline earth metal carbonate film into an alkaline earth metal oxide. After performing an appropriate number of alkaline earth metal oxide deposition cycles 115, according to Figure 1 the method of the embodiment ends 114. Thus, a layer comprising an alkaline earth metal can be formed. The layer can have a thickness, for example, of at least 0.3 nm to at most 1 mm, or at least 1 nm to at most 100 μm, or at least 10 nm to at most 10 μm, or at least 100 nm to at most 1 μm.

[0047] The resulting alkaline earth metal oxide can have excellent quality and can be included in the gate dielectric of a transistor or in the dielectric of a capacitor such as a metal-insulator-metal capacitor. In some embodiments, the resulting alkaline earth metal oxide can have a high dielectric constant and thus can be used as a high-k material.

[0048] As described in the context of Figure 1 forming an alkaline earth metal carbonate can include performing a cyclic deposition process that includes one or more alkaline earth metal carbonate deposition cycles 112. Suitably, now referring to Figure 2 , the alkaline earth metal carbonate deposition cycle 112 can include an alkaline earth metal precursor pulse 201 and a first reactant pulse 202. The alkaline earth metal precursor pulse 201 includes exposing the substrate to an alkaline earth metal precursor. The alkaline earth metal precursor includes an alkaline earth metal. The first reactant pulse 202 includes exposing the substrate to a first reactant. Optionally, subsequent pulses can be separated by purging.

[0049] In some embodiments, forming the alkaline earth metal carbonate can include performing at least 1 to at most 100 subsequent alkaline earth metal carbonate deposition cycles 112, or at least 2 to at most 50 subsequent alkaline earth metal carbonate deposition cycles 112, or at least 5 to at most 20 subsequent alkaline earth metal carbonate deposition cycles 112, or about 10 alkaline earth metal carbonate deposition cycles 112.

[0050] Now referring Figure 3 , embodiments of a method 300 for forming a layer comprising an alkaline earth metal, a transition metal, and oxygen are further described herein. The layer can be formed on a substrate. According to Figure 3 an embodiment of the method 300 includes the step of providing a substrate to a reaction chamber. The method further includes performing a plurality of deposition cycles 315. The deposition cycles from the plurality of deposition cycles 315 include forming an alkaline earth metal carbonate 312. In some embodiments, forming the alkaline earth metal carbonate 312 can be accomplished by performing one or more alkaline earth metal carbonate sub-cycles. The deposition cycles from the plurality of deposition cycles 315 further include an oxidant pulse 313. In some embodiments, the oxidant pulse 313 directly follows the formation of the alkaline earth metal carbonate 312. The oxidant pulse 313 can suitably convert the alkaline earth metal carbonate into an alkaline earth metal oxide. The deposition cycles from the plurality of deposition cycles 315 further include forming a transition metal oxide 314. Forming the transition metal oxide 314 can be accomplished by performing one or more transition metal oxide deposition cycles 314. Thus, in some embodiments, a laminated layer structure including alternating layers of an alkaline earth metal oxide layer and a transition metal oxide layer can be formed. Alternatively, the resulting layer can have a uniform composition. For example, a uniform composition can be obtained by annealing the laminated layer structure and thereby allowing diffusion to homogenize the composition of the resulting layer. Additionally or alternatively, a uniform composition can be obtained by continuously performing a relatively small number of alkaline earth metal carbonate deposition cycles and continuously performing transition metal oxide deposition cycles. In fact, a substantially uniform layer structure can be obtained by forming a stack of alternating very thin layers.

[0051] The resulting binary oxide comprising an alkaline earth metal and a transition metal can have excellent quality and can be included in the gate dielectric of a transistor or in the dielectric of a capacitor such as a metal-insulator-metal capacitor. In some embodiments, the resulting binary oxide can have a high dielectric constant and can thus be used as a high-k material.

[0052] Advantageously, forming (e.g., periodically forming) a carbonate and then oxidizing the carbonate to form an oxide allows the oxide to be formed at a high growth rate. For example, in the cyclic deposition process described herein, such as an atomic layer deposition process, and using Sr(iPr 3 Cp) 2As an alkaline earth metal precursor, it has been found impossible to use ozone as a reactant to grow SrO films with acceptable growth per cycle. The subject matter of the present disclosure is not bound by any particular theory or mode of operation, and it is believed that strontium oxide is not grown using Sr(iPr 3 Cp) 2 a good nucleation surface for continued growth. Embodiments of the present disclosure solve this problem by first growing strontium carbonate and then converting the strontium carbonate to strontium oxide, resulting in the growth of the oxide at a high growth rate.

[0053] Forming an alkaline earth metal carbonate may include performing a cyclic deposition process including one or more alkaline earth metal carbonate deposition cycles 112. The alkaline earth metal carbonate deposition cycle from one or more alkaline earth metal carbonate deposition cycles may include an alkaline earth metal precursor pulse 201 and a first reactant pulse 202, as described in the context of Figure 2 .

[0054] Forming a transition metal oxide may include performing a cyclic deposition process including one or more transition metal oxide deposition cycles 314, as illustrated by Figure 4 . In fact, the transition metal oxide deposition cycle from one or more transition metal oxide deposition cycles 314 may include performing a transition metal precursor pulse 401 and a second reactant pulse 402. The transition metal precursor pulse 401 may include exposing the substrate to a transition metal precursor. The transition metal precursor may include a transition metal. The second reactant pulse 402 may include exposing the substrate to a second reactant. Optionally, subsequent pulses may be separated by purging.

[0055] In some embodiments, the deposition cycles from multiple deposition cycles 315 may include an equal number of alkaline earth metal deposition cycles and transition metal deposition cycles. In some embodiments, for each transition metal deposition cycle, the deposition cycles from multiple deposition cycles 315 may include from 0.01 to 100 alkaline earth metal carbonate deposition cycles. In some embodiments, for each transition metal deposition cycle, the deposition cycles from multiple deposition cycles 315 may include from 0.02 to 50 alkaline earth metal carbonate deposition cycles. In some embodiments, for each transition metal deposition cycle, the deposition cycles from multiple deposition cycles 315 may include from 0.05 to 20 alkaline earth metal carbonate deposition cycles. In some embodiments, for each transition metal deposition cycle, the deposition cycles from multiple deposition cycles 315 may include from 0.1 to 10 alkaline earth metal carbonate deposition cycles. In some embodiments, for each transition metal deposition cycle, the deposition cycles from multiple deposition cycles 315 may include from 0.5 to 2 alkaline earth metal carbonate deposition cycles.

[0056] In some embodiments, the first reactant and the second reactant are independently selected from oxygen reactants such as H 2 O, H 2 O 2 、O 2 、O 3 。In some embodiments, the oxygen reactant may include one or more plasma-generated species such as oxygen ions or radicals. In some embodiments, the first reactant and the second reactant are the same. In some embodiments, the first reactant and the second reactant are different. In some embodiments, the first reactant and the second reactant include ozone.

[0057] In some embodiments, the alkaline earth metal precursor includes strontium and the transition metal precursor includes niobium. Thus, an oxide containing strontium and niobium, such as a binary oxide, can be formed. In some embodiments, the material formed includes Sr 2 Nb 3 O 10 ,which may desirably have a high dielectric constant and a low defect rate.

[0058] In some embodiments, the alkaline earth metal is selected from beryllium, magnesium, calcium, strontium, and barium. In some embodiments, the alkaline earth metal includes strontium.

[0059] In some embodiments, the alkaline earth metal precursor includes a compound having the general formula M(R n Cp) 2 where M is an alkaline earth metal, R is a C1 to C6 alkyl group, and n is an integer from at least 0 to at most 3. In some embodiments, M is strontium, R is isopropyl, and n is 3.

[0060] In some embodiments, R is selected from methyl, ethyl, propyl, butyl, and pentyl.

[0061] In some embodiments, n is 0, 1, 2, or 3.

[0062] In some embodiments, the alkaline earth metal precursor includes a compound having the following general formula:

[0063]

[0064] where M is an alkaline earth metal and R is a C1 to C6 alkyl group. In some embodiments, M is strontium and R is tert-butyl.

[0065] In some embodiments, the transition metal precursor includes an element selected from the following: scandium, titanium, vanadium, chromium, manganese, iron, cobalt, nickel, copper, zinc, yttrium, zirconium, niobium, molybdenum, ruthenium, rhodium, palladium, silver, cadmium, lutetium, hafnium, tantalum, tungsten, rhenium, osmium, iridium, platinum, gold, and mercury. In some embodiments, the transition metal precursor includes niobium.

[0066] In some embodiments, the transition metal precursor comprises one or more alkylamido ligands.

[0067] In some embodiments, the transition metal precursor comprises one or more alkylimido ligands.

[0068] In some embodiments, the transition metal precursor includes a heteroleptic precursor. The heteroleptic precursor may comprise one or more alkylamido ligands and one or more alkylimido ligands.

[0069] In some embodiments, the transition metal precursor includes tris(diethylamido)(tert-butylimido)niobium.

[0070] In some embodiments, the transition metal precursor corresponds to the following general formula:

[0071]

[0072] wherein M is a transition metal, R 1 and R 2 are independently selected from C1 to C6 alkyl groups. In some embodiments, M is niobium. In some embodiments, R 1 is ethyl. In some embodiments, R 2 is butyl. In some embodiments, R 2 is tert-butyl.

[0073] In some embodiments, R 1 is methyl. In some embodiments, R 1 is ethyl. In some embodiments, R 1 is propyl. In some embodiments, R 1 is butyl. In some embodiments, R 1 is pentyl. In some embodiments, R 1 is hexyl.

[0074] In some embodiments, R 2 is methyl. In some embodiments, R 2 is ethyl. In some embodiments, R 2 is propyl. In some embodiments, R 2 is butyl. In some embodiments, R 2 is pentyl. In some embodiments, R 2 is hexyl.

[0075] In some embodiments, the oxidant includes an oxygen reactant. In some embodiments, the oxygen reactant is selected from H 2 O, H 2 O 2 O 2 and O 3. In some embodiments, the oxygen reactant includes one or more plasma species, such as oxygen ions and oxygen radicals.

[0076] In some embodiments, the oxidizing agent includes ozone.

[0077] In some embodiments, the first reactant and the second reactant are independently selected. In some embodiments, the first reactant and the second reactant are the same. In some embodiments, the first reactant and the second reactant are different.

[0078] In some embodiments, at least one of the first reactant and the second reactant includes a chalcogen element.

[0079] In some embodiments, at least one of the first reactant and the second reactant includes ozone.

[0080] In some embodiments, the first reactant includes O 3 , and the second reactant includes H 2 O.

[0081] In some embodiments, the oxidizing agent includes O 3 , the first reactant includes O 3 , and the second reactant includes H 2 O.

[0082] In some embodiments, the oxidizing agent includes O 3 , the first reactant includes O 3 , and the second reactant includes H 2 O or O 3 .

[0083] In some embodiments, the oxidizing agent pulse duration is longer than the first reactant pulse. Thus, in some embodiments, the first reactant pulse has a first duration, the oxidizing agent pulse has an oxidizing agent pulse duration, and the oxidizing agent pulse duration is longer than the first duration. In some embodiments, both the oxidizing agent and the first reactant include ozone.

[0084] In some embodiments, at least one of the first reactant pulse, the second reactant pulse, and the oxidizing agent pulse may include a plurality of micro-pulses 601 and micro-purges 602 as shown in Figure 6 , for example, 2, 4, 6, 8, 10 or more micro-pulses 601 and micro-purges 602. In such embodiments, the pulse 600 may include short reactant or oxidizing agent pulses in rapid succession and be purged with a purge gas. For example, the micro-pulse may be performed for 0.2 seconds, the micro-purge may be performed for 0.5 seconds, and this pulse-purge cycle may be repeated 10 times.

[0085] In some embodiments, the methods described herein are carried out at a temperature of at least 100 °C to at most 400 °C, or at least 150 °C to at most 350 °C, or at least 200 °C to at most 300 °C, or about 250 °C.

[0086] In some embodiments, a layer comprising an alkaline earth metal and a transition metal formed using the methods described herein has an alkaline earth metal content of at least 5 atomic % to at most 95 atomic % and a transition metal content of at least 5 atomic % to at most 95 atomic %. In some embodiments, a layer comprising an alkaline earth metal and a transition metal formed using the methods described herein has an alkaline earth metal content of at least 10 atomic % to at most 90 atomic % and a transition metal content of at least 10 atomic % to at most 90 atomic %. In some embodiments, a layer comprising an alkaline earth metal and a transition metal formed using the methods described herein has an alkaline earth metal content of at least 20 atomic % to at most 80 atomic % and a transition metal content of at least 20 atomic % to at most 80 atomic %. In some embodiments, a layer comprising an alkaline earth metal and a transition metal formed using the methods described herein has an alkaline earth metal content of at least 30 atomic % to at most 70 atomic % and a transition metal content of at least 30 atomic % to at most 70 atomic %. In some embodiments, a layer comprising an alkaline earth metal and a transition metal formed using the methods described herein has an alkaline earth metal content of at least 40 atomic % to at most 60 atomic % and a transition metal content of at least 40 atomic % to at most 60 atomic %. These compositions can be determined using X-ray photoelectron spectroscopy (XPS) and are expressed on a total metal basis, e.g., relative to the sum of the alkaline earth metal content and the transition metal content, without considering oxygen atoms.

[0087] The present disclosure further describes a system including a reaction chamber and a controller. The system is configured and arranged to perform the methods described herein.

[0088] Reference Figure 5 , system 500 may include two reaction chambers 510, 520, specifically an alkaline earth metal reaction chamber 510 and a transition metal reaction chamber 520. The alkaline earth metal reaction chamber 510 may be configured and arranged to perform a plurality of alkaline earth metal deposition cycles. The transition metal reaction chamber 520 may be configured and arranged to perform a plurality of transition metal deposition cycles. System 500 further includes a substrate transfer robot 530, which is configured and arranged to move substrates from, to, and between the alkaline earth metal reaction chamber 510 and the transition metal reaction chamber 520. System 500 may further include a controller 540, which is configured and arranged to cause system 500 to perform the methods described herein. For example, in accordance with Figure 3In the method 300 of an embodiment, the substrate can be cycled between an alkaline earth metal reaction chamber 510 for forming an alkaline earth metal carbonate and a transition metal reaction chamber 520 for forming a transition metal oxide. The oxidant pulse 313 can be performed in the alkaline earth metal reaction chamber 520 after forming the alkaline earth metal carbonate, or in the transition metal reaction chamber 530 before forming the transition metal oxide 314. Cycling the substrate in this way can be particularly advantageous when the alkaline earth metal carbonate and the transition metal are formed at different temperatures, which may help, for example, to obtain a ternary film with a desired stoichiometry, such as Sr 2 Nb 3 O 10 with a high dielectric constant. Of course, in some embodiments, all steps of the method 300 according to Figure 3 the embodiment can also be performed using only one reaction chamber.

[0089] In some embodiments, the alkaline earth metal reaction chamber 510 and the transition metal reaction chamber 520 can be cyclic deposition, such as atomic layer deposition (ALD) reaction chambers. In such an embodiment, a certain number of cycles, such as 10 to 20 cycles, can be performed in each of the reaction chambers 510, 520 before moving the substrate to the next one. Thus, a nano-stack containing alternating layers of an alkaline earth metal oxide and a transition metal oxide can be formed. Such a nano-stack itself can have a large dielectric constant. Alternatively, such a nano-stack can be annealed to form a uniform or substantially uniform dielectric.

[0090] The reactants used in the two reaction chambers 510, 520 can be the same or different. In some embodiments, the first reactant includes O 3 , and the second reactant includes H 2 O, which can be done, for example, to form a nano-stack as described herein, such as alternating layers of strontium oxide and niobium oxide. In such an embodiment, the transition metal reaction chamber 520 can be maintained at a higher temperature than the alkaline earth metal reaction chamber.

[0091] By performing the constituent deposition processes of the stack in different reaction chambers, these processes can be performed under optimal reaction conditions, which can advantageously increase the growth rate, improve the conformality, and reduce the carbon content.

[0092] In an exemplary embodiment, the alkaline earth metal reaction chamber 510 can be used to form and oxidize a strontium carbonate layer to form strontium oxide flakes using atomic layer deposition. The alkaline earth metal reaction chamber 510 can be maintained at a temperature of 300 °C or higher and can be used to perform 10 to 15 consecutive cycles before oxidation. Strontium bis(2,2,6,6-tetramethyl-3,5-heptanedionate) or (iPr 3 Cp) 2Sr can be used as a precursor. Water can be used as a reactant.

[0093] In an exemplary embodiment, the transition metal reaction chamber 520 can be used to form a transition metal oxide thin film using atomic layer deposition. The transition metal reaction chamber 520 can be maintained at a temperature of at least 200 °C to at most 275 °C. Tris(diethylamido)(tert-butylimido)niobium can be used as a precursor, and ozone or water can be used as a reactant.

[0094] In an exemplary embodiment, ozone is used as an oxidant. Advantageously, it has been found that the carbon concentration in the strontium niobium oxide film is reduced when ozone is used as an oxidant in the method according to Figure 3 the embodiment.

[0095] Reference Figure 7 is made to system 700, which is constructed and arranged to perform embodiments of the methods described herein.

[0096] In the illustrated example, system 700 includes one or more reaction chambers 702, a precursor gas source 704, a reactant gas source 706, a purge gas source 708, an exhaust source 710, and a controller 712. Of course, in some embodiments, there may be other gas sources. For example, system 700 can include all of an alkaline earth metal precursor source, a transition metal precursor source, a first reactant source, a second reactant source, and an oxidant source. The reaction chamber 702 can include any suitable reaction chamber, such as an ALD or CVD reaction chamber. For simplicity, system 700 is described only with reference to a general precursor gas source 704 and a general reactant gas source 706.

[0097] The precursor gas source 704 can include a container and one or more precursors as described herein—either alone or mixed with one or more carrier gases (such as inert gases). The reactant gas source 706 can include a container and one or more reactants as described herein—either alone or mixed with one or more carrier gases. The purge gas source 708 can include one or more purge gases as described herein. Although three gas sources 704-708 are shown, system 700 can include any suitable number of gas sources. The gas sources 704-708 can be coupled to the reaction chamber 702 via lines 714-718, which can each include a flow controller, a valve, a heater, etc. The exhaust source 710 can include one or more vacuum pumps.

[0098] The controller 712 includes electronic circuitry and software to selectively operate valves, manifolds, heaters, pumps, and other components included in system 700. Such circuitry and components are used to introduce precursors, reactants, and purge gases from corresponding sources 704 - 708. The controller 712 can control the timing of gas pulse sequences, the temperature of the substrate and / or reaction chamber, the pressure within the reaction chamber, and various other operations to provide proper operation of system 700. The controller 712 can include control software to control valves, either electrically or pneumatically, to control the flow of precursors, reactants, and purge gases into and out of reaction chamber 702. The controller 712 can include modules that perform certain tasks, such as software or hardware components, such as an FPGA or ASIC. The modules can be advantageously configured to reside on an addressable storage medium of the control system and configured to execute one or more processes.

[0099] Other configurations of system 700 are possible, including different numbers and types of precursor and reactant sources and purge gas sources. Additionally, it should be understood that there are many arrangements of valves, conduits, precursor sources, and purge gas sources that can be used to achieve the goal of selectively supplying gases to reaction chamber 702. Further, as a schematic representation of the system, many components have been omitted for simplicity of illustration, and these components can include, for example, various valves, manifolds, purifiers, heaters, containers, vents, and / or bypasses.

[0100] During operation of the reactor system 700, a substrate, such as a semiconductor wafer (not shown), is transferred from, for example, a substrate handling system to reaction chamber 702. Once the substrate is transferred to reaction chamber 702, one or more gases from gas sources 704 - 708, such as precursors, reactants, carrier gases, and / or purge gases, are introduced into reaction chamber 702.

[0101] A composition is also described that is configured to form a layer comprising a transition metal and an alkaline earth metal on a substrate, the composition comprising one or more of the alkaline earth metal precursors and transition metal precursors described herein.

[0102] A container is also described that includes at least one of the alkaline earth metal precursors and transition metal precursors described herein, wherein the container is configured to provide a vapor of a chemical precursor to a semiconductor processing equipment chamber included in the system described herein.

[0103] A film deposition product containing an alkaline earth metal and a transition metal, the product comprising: the alkaline earth metal precursor and transition metal precursor as described above; a first container containing the alkaline earth metal precursor; and a second container containing the transition metal precursor, wherein the first and second containers are configured to be coupled to a semiconductor device, such as the system described herein, via a reactant delivery system.

Claims

1. A method for forming a layer comprising an alkaline earth metal and oxygen, the method comprising: - providing a substrate to a reaction chamber; - performing a plurality of alkaline earth metal oxide deposition cycles, the alkaline earth metal oxide deposition cycle from the plurality of alkaline earth metal oxide deposition cycles comprising: - one or more alkaline earth metal carbonate precipitation cycles to form alkaline earth metal carbonate, and - an oxidant pulse comprising exposing the substrate to an oxidant to convert the alkaline earth carbonate film into an alkaline earth oxide; Wherein, the alkaline earth metal carbonate deposition cycle from one or more alkaline earth metal carbonate deposition cycles comprises: - an alkaline earth metal precursor pulse comprising exposing the substrate to an alkaline earth metal precursor, the alkaline earth metal precursor comprising an alkaline earth metal, and - a first reactant pulse comprising exposing the substrate to a first reactant.

2. A method of forming a layer on a substrate, the layer comprising an alkaline earth metal, a transition metal and oxygen, the method comprising: - providing a substrate to a reaction chamber; - performing a plurality of alkaline earth metal oxide deposition cycles, the alkaline earth metal oxide deposition cycle from the plurality of alkaline earth metal oxide deposition cycles comprising: - one or more alkaline earth metal carbonate precipitation cycles to form alkaline earth metal carbonate, - an oxidant pulse, which comprises exposing the substrate to an oxidant to convert the alkaline earth metal carbonate film into an alkaline earth metal oxide, and - one or more transition metal oxide deposition cycles to form a transition metal oxide; Wherein, the alkaline earth metal carbonate deposition cycle from one or more alkaline earth metal carbonate deposition cycles comprises: - an alkaline earth metal precursor pulse comprising exposing the substrate to an alkaline earth metal precursor, the alkaline earth metal precursor comprising an alkaline earth metal, and - a first reactant pulse comprising exposing the substrate to a first reactant; Wherein, the transition metal oxide deposition cycle from the one or more transition metal oxide deposition cycles comprises: - a transition metal precursor pulse comprising exposing the substrate to a transition metal precursor comprising a transition metal; and - a second reactant pulse comprising exposing the substrate to a second reactant.

3. The method according to claim 1 or 2, wherein: The alkaline earth metal includes strontium.

4. The method according to claim 1 or 2, wherein: The alkaline earth metal precursor comprises a n Cp)2, wherein M is an alkaline earth metal, R is a C1 to C6 alkyl group, and n is an integer of at least 0 and at most 3.

5. The method according to any one of claims 2 to 4, wherein: The transition metal precursor comprises niobium.

6. The method according to any one of claims 2 to 5, wherein: The transition metal precursor comprises one or more alkylamide ligands.

7. The method according to any one of claims 2 to 6, wherein: The transition metal precursor comprises one or more alkylimino ligands.

8. The method according to any one of claims 2 to 7, wherein: The transition metal precursor includes a heteroleptic precursor, and the heteroleptic precursor includes one or more alkyl amide ligands and one or more alkyl imino ligands.

9. The method according to claim 4, wherein: The transition metal precursor includes tris(diethylamido)(tert-butylimide)niobium.

10. The method according to any one of claims 1 to 9, wherein: The oxidant includes an oxygen reactant selected from H2O, H2O2, O2, O3, oxygen ions and oxygen free radicals.

11. The method according to any one of claims 1 to 9, wherein: The oxidant comprises ozone.

12. The method according to any one of claims 1 to 11, wherein: At least one of the first reactant and the second reactant includes a chalcogen.

13. The method according to any one of claims 1 to 12, wherein: At least one of the first reactant and the second reactant comprises ozone.

14. The method according to any one of claims 1 to 13, wherein: The first reactant pulse has a first duration, wherein the oxidant pulse has an oxidant pulse duration, and wherein the oxidant pulse duration is longer than the first duration.

15. The method according to any one of claims 1 to 14, wherein: The oxidant includes O3, the first reactant includes O3, and the second reactant includes H2O or O3.

16. A system comprising a reaction chamber and a controller, the system being constructed and arranged to perform the method according to any one of claims 1 to 15.

17. The system of claim 16, comprising an alkaline earth carbonate reaction chamber constructed and arranged to form an alkaline earth carbonate and a transition metal reaction chamber constructed and arranged to form a transition metal oxide.

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