Methods, systems, and apparatus for forming metal oxide layers

Abstract

Methods, systems, and apparatus for forming one or more metal oxide layers on a substrate are disclosed. An example method includes a) providing a substrate in a reaction chamber, b) flowing a first precursor comprising zinc or gallium or a combination thereof and an oxygen species into the reaction chamber to deposit a first oxide layer on a top surface of the substrate, c) flowing a second precursor into the chamber to deposit a second oxide layer on the first oxide layer, and d) depositing a second oxide layer on the second oxide layer. Wherein the second precursor comprises aluminum having at least one R ligand and at least one L ligand, where the R ligand is an alkyl ligand, and where the R ligand and the L ligand are different, and repeating steps b) or c) or a combination thereof until a desired thickness of the first oxide layer or the second oxide layer or a combination thereof is achieved.

Description

Technical Field

[0001] The present disclosure relates generally to the field of semiconductor processing methods and systems, and to the field of electronic devices, and in particular, to methods and systems suitable for forming layers comprising metal oxides. Background Art

[0002] The reduction in size of semiconductor devices, such as complementary metal oxide semiconductor (CMOS) devices, has led to significant increases in the speed and density of integrated circuits. However, conventional device scaling techniques face significant challenges at future technology nodes.

[0003] For example, one challenge is to find suitable conductive materials for use as gate electrodes, especially as threshold voltage shifting materials in large-scale CMOS devices. Therefore, there is a need for improved materials for gate electrodes. In particular, such materials can include a dipole mobile layer and can be used for threshold voltage tuning. Summary of the invention

[0004] This summary is provided to introduce some concepts in a simplified form. These concepts are further described in detail in the detailed description of the example embodiments disclosed below. This summary is not intended to necessarily 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.

[0005] In one aspect, a method of depositing one or more metal oxide layers on a substrate is disclosed. The method comprises a) providing a substrate in a reaction chamber, b) flowing a first precursor comprising zinc or gallium or a combination thereof and an oxygen species into the chamber to deposit a first oxide layer on a top surface of the substrate, c) flowing a second precursor into the chamber to deposit a second oxide layer on the first oxide layer, wherein the second precursor comprises aluminum having at least one R ligand and at least one L ligand, wherein the R ligand is an alkyl ligand, and wherein the R ligand and the L ligand are different, and repeating steps b) or c) or a combination thereof until a desired thickness of the first oxide layer or the second oxide layer or a combination thereof is achieved.

[0006] In some examples, the first precursor may include one or more of alkyl zinc, zinc halide, β-diketonate zinc, alkoxy zinc, and alkyl amide zinc. In some examples, the first precursor may be selected from diethyl zinc (DEZ), dimethyl zinc (DMZ), and zinc acetylacetonate (Zn(acac)2). In some examples, the first precursor may include one or more of β-diketonate gallium, alkoxy gallium, alkyl gallium, alkyl amide gallium, gallium halide, and gallium alkane. In some examples, the first precursor may be selected from gallium (III) acetylacetonate, dimethyl gallium isopropoxide, gallium chloride, trimethyl gallium (TMGa), tris (dimethylamino) gallium (TDMAGa), and triethyl gallium (TEGa).

[0007] In some examples, the second precursor formula can be AlRxLy, where x+y=3, or where the second precursor formula is Al2RxLy, where x+y=6. In various examples, the R ligand can include a branched or unbranched alkyl group containing 1 to 6 carbon atoms. In various examples, at least one L ligand can be an alkoxide, a dialkylamido group, or an amidine group. In some examples, the alkoxide L ligand can be selected from methoxide, ethoxide, 1-propoxide, isopropoxide, 1-butoxide, 2-butoxide, isobutoxide, tert-butoxide, 1-pentoxide, 2-pentoxide, 3-pentoxide, isopentoxide, tert-pentoxide, and neopentoxide.

[0008] In some examples, the dialkyl amido ligand can be selected from dimethylamino, ethylmethylamido and diethylamido. In some examples, the amidine L ligand can be selected from N, N'-diisopropylacetamido, N, N'-di-tert-butylacetamido, N, N'-diisopropylformamido and N, N'-di-tert-butylformamido. In some examples, the L ligand can include a hydrocarbon group containing 1 to 10 carbon atoms and a nitrogen (N) atom or an oxygen (O) atom or a combination thereof bonded to an aluminum (Al) atom, wherein the L ligand is bonded to the Al atom through two different atoms. In some examples, the hydrocarbon group can be branched, unbranched, cyclic or aromatic, or a combination thereof. In some examples, the thickness of the first oxide layer is approximately between 0.5 and 20 angstroms thick.

[0009] In some examples, the first oxide layer may be a zinc oxide layer. In some examples, the zinc oxide layer may include zinc oxide, aluminum-doped zinc oxide, or indium gallium zinc oxide, or a combination thereof. In some examples, the first oxide layer may be a gallium oxide layer. In some examples, the gallium oxide layer may include gallium oxide (GaO), indium gallium oxide (IGO), gallium zinc oxide (GaZnO), or indium gallium zinc oxide (IGZO), or a combination thereof.

[0010] In some examples, a second oxide layer of a first thickness may be deposited using a second precursor, and a second oxide layer of a second thickness may be deposited using a third precursor. In some examples, the second precursor is different from the third precursor. In some examples, the second oxide layer may be aluminum oxide. In some examples, the first thickness of the second oxide layer is in a range of about 1 angstrom to about 20 angstroms, and the second thickness of the second oxide layer is in a range of about 0.5 angstroms to about 20 angstroms. In some examples, the third precursor includes trimethylaluminum (TMA), and wherein the second oxygen species includes at least one of water (H2O) or ozone (O3).

[0011] To summarize the present disclosure and the advantages achieved relative to the prior art, certain objects and advantages of the present disclosure have been described above. Of course, it should be understood that not all of these objects or advantages may be achieved according to any particular embodiment or example of the present disclosure. Thus, for example, those skilled in the art will recognize that the examples disclosed herein may be implemented in a manner that achieves or optimizes one advantage or a group of advantages taught or suggested herein, without necessarily achieving other objects or advantages taught or suggested herein. All of these examples are within the scope of the present disclosure. These and other embodiments will become apparent to those skilled in the art by the following detailed description of certain examples with reference to the accompanying drawings, and the present disclosure is not limited to any particular example discussed. BRIEF DESCRIPTION OF THE DRAWINGS

[0012] Although the specification concludes with claims that particularly point out and distinctly claim what are considered to be embodiments or examples of the present disclosure, advantages of examples of the present disclosure may be more readily ascertained from the description of certain examples of the present disclosure when read in conjunction with the accompanying drawings. Elements having the same element number are identical in all drawings.

[0013] Figure 1 A schematic diagram of a reactor system according to an example of the present technology is shown.

[0014] Figure 2 A schematic diagram of a reactor system having multiple reaction chambers according to an example of the present technology is shown.

[0015] Figure 3 A device structure according to an example of the present technology is shown.

[0016] Figure 4 A deposition method according to an example of the present technology is shown.

[0017] Figure 5 A deposition method according to an example of the present technology is shown.

[0018] Figure 6 A device structure according to an example of the present technology is shown.

[0019] Figure 7 A device structure according to an example of the present technology is shown. DETAILED DESCRIPTION

[0020] The detailed description of various examples herein refers to the accompanying drawings, which illustrate exemplary examples by way of illustration. Although these exemplary examples are described in sufficient detail to enable those skilled in the art to practice the present disclosure, it should be understood that other examples may be implemented without departing from the spirit and scope of the present disclosure, and logical, chemical and / or mechanical changes may be made. Therefore, the detailed description here is only for the purpose of illustration, not for limitation. For example, the steps described in any method or process description may be performed in any combination and / or order, and are not limited to the presented combination and / or order. In addition, one or more steps from one of the disclosed methods or processes may be combined with one or more steps from another in the disclosed method or process in any suitable combination and / or order. In addition, any function or step may be outsourced to one or more third parties or performed by a third party. In addition, any reference to the singular includes plural examples, and any reference to more than one component may include a singular example.

[0021] Although certain embodiments and examples are disclosed below, those skilled in the art will appreciate that the disclosure extends beyond the specifically disclosed examples and / or uses of the disclosure and obvious modifications and equivalents thereof. Therefore, it is intended that the scope of the disclosure should not be limited by the specific examples described herein.

[0022] The illustrations presented herein are not meant to be actual views of any particular material, apparatus, structure, or device, but are merely representations of examples used to describe the present disclosure.

[0023] As used herein, the term "substrate" may refer to any underlying material or materials that may be used or upon which a device, circuit, or film / layer may be formed.

[0024] As used herein, the term "atomic layer deposition" (ALD) may refer to a vapor deposition process in which a deposition cycle, preferably a plurality of consecutive deposition cycles, is performed in a processing chamber. Typically, during each cycle, a precursor is chemically adsorbed to a deposition surface (e.g., a substrate surface or a previously deposited underlying surface, such as material from a previous ALD cycle) to form a monolayer or sub-monolayer that is not easily reacted with additional precursors (i.e., a self-limiting reaction). Thereafter, if desired, a reactant (e.g., another precursor or a reactive gas) may be subsequently introduced into the processing chamber for converting the chemically adsorbed precursor into the desired material on the deposition surface. Typically, the reactant is capable of further reacting with the precursor. In addition, a purge step may also be utilized during each cycle to remove excess precursor from the processing chamber and / or excess reactant and / or reaction byproducts from the processing chamber after the chemically adsorbed precursor is converted. In addition, as used herein, the term "atomic layer deposition" is also meant to include processes designated by related terms, such as "chemical vapor atomic layer deposition", "atomic layer epitaxy" (ALE), molecular beam epitaxy (MBE), gas source MBE or organometallic MBE, and chemical beam epitaxy when performed with alternating pulses of a precursor composition, a reactive gas, and a purge gas (e.g., an inert carrier gas).

[0025] As used herein, the term "chemical vapor deposition" (CVD) may refer to any process in which a substrate is exposed to one or more volatile precursors that react and / or decompose on the substrate surface to produce the desired deposit.

[0026] As used herein, the terms "layer", "film" and / or "thin film" may refer to any continuous or discontinuous structure and material deposited by the methods disclosed herein. For example, a "layer", "film" and / or "thin film" may include a 2D material, nanorods, nanotubes or nanoparticles, or even a partial or complete molecular layer or a partial or complete atomic layer or clusters of atoms and / or molecules. A "layer", "film" and / or "thin film" may include a material or layer having pinholes, but still at least partially continuous.

[0027] In addition, in the present disclosure, any two numbers of a variable may constitute a feasible range for the variable, and any range indicated may include or exclude endpoints. In addition, any values ​​of the variables indicated (regardless of whether they are expressed as "about") may refer to exact values ​​or approximate values, and include equivalents, and may refer to average values, median values, representative values, majority values, etc. In addition, in the present disclosure, the terms "including", "consisting of" and "having" may independently refer to "generally or broadly including", "comprising", "essentially consisting of" or "consisting of" in some examples. In the present disclosure, the meaning of any definition does not necessarily exclude the common and customary meanings in some examples.

[0028] Figure 1 A schematic diagram of a reactor system 50 according to an example of the present technology is shown. Reactor systems for ALD, CVD, etc. can be used for various applications, including on a substrate surface (e.g., surface 702 and / or 704, see Figure 7 ) is deposited and etched on the substrate 30. In various embodiments, the reactor system 50 may include a reaction chamber 4, a pedestal 6 to hold the substrate 30 during processing, a fluid distribution system 8 (e.g., a showerhead) to distribute one or more reactants to the surface of the substrate 30, one or more reactant sources 10, 12, 13 and / or a carrier gas and / or purge gas source 14, which are fluidly coupled to the reaction chamber 4 through corresponding pipelines 16, 18, 19 and 20 and corresponding valves or controllers 22, 24, 25 and 26. Reactant gases or other materials from the reactant sources 10, 12 and 13 can be applied to the substrate 30 in the reaction chamber 4. Purge gas from the purge gas source 14 can flow to and through the reaction chamber 4 to remove any excess reactants or other unwanted substances from the reaction chamber 4. The system 50 can also include a vacuum source 28 fluidly coupled to the reaction chamber 4, which can be configured to exhaust reactants, purge gases or other materials from the reaction chamber 4.

[0029] In various examples, the reactor system 50 may include multiple reaction chambers. Figure 2 In the reactor system 200 shown, a plurality of reaction chambers 204 (each reaction chamber can be Figure 1 The transfer chamber 280 may be disposed around and / or coupled to the transfer chamber 280, which includes a transfer tool 285 for transferring substrates between the reaction chambers 204. The substrate may be transferred between the load lock chamber 212 and the reaction chamber 204 (e.g., via the transfer chamber 280). For example, the substrate 30 may be disposed in different chambers for different steps in the deposition process.

[0030] Figure 4 Depicted is a method 400 of depositing layers on a substrate to form a device structure, such as Figure 3 The device structure 300 is shown. The device structure 300 may be a gate electrode structure suitable for use in NMOS, PMOS and / or CMOS devices, for example, as a p-dipole shifter in a gate, source or drain electrode of a metal oxide semiconductor. However, unless otherwise stated, the methods described herein are not limited to these applications.

[0031] Combined with reference Figure 1 , 3 and 4, the method 400 may include in a reaction chamber (e.g. Figure 1 Provide a substrate 330 in a reaction chamber 4 in step 402. The substrate 330 may be disposed on a base (eg Figure 1In one example, the method may further include forming a first oxide layer 340 including zinc or gallium (step 408).

[0032] In one example, the first oxide layer 340 may include a zinc oxide (ZnO) layer, and may include binary ZnO and ternary and quaternary zinc oxide films such as aluminum-doped zinc oxide (ZnAlOx) and indium gallium zinc oxide (IGZO). In another example, the first oxide layer 340 may be a gallium oxide (GaO) layer. The gallium oxide (GaO) layer may include binary GaO and gallium-containing ternary and quaternary films such as indium gallium oxide (IGO), gallium zinc oxide (GaZnO), and / or indium gallium zinc oxide (IGZO). Other zinc or gallium-containing oxides may be used, and the claimed subject matter is not limited thereto.

[0033] In various examples, forming the first oxide layer 340 may include providing a first precursor to the reaction chamber 4 (step 404). The first precursor may include a zinc precursor or a gallium precursor or a combination thereof. The first precursor may be provided to the reaction chamber 4 to the substrate 330 through a showerhead 8 from one or more reactant sources 10, 12, and / or 13, or provided by a cross-flow fluid distribution system. The first precursor may be pulsed into the reaction chamber 4 for any suitable duration (e.g., a pulse time between 0.05 and 100 seconds). During the provision of the first precursor, the pressure within the reaction chamber 4 may be any suitable pressure, such as between 1 and 50 Torr.

[0034] In various examples, the first oxide layer 340 may include zinc oxide. In such examples, the first precursor may be any suitable zinc-containing compound, including but not limited to alkyl zinc, zinc halide, β-diketonate zinc, alkoxy zinc, and / or alkyl amide zinc. For example, the zinc precursor may include diethyl zinc (DEZ), dimethyl zinc (DMZ), and acetylacetonate zinc (Zn(acac)2).

[0035] In various examples, the first oxide layer 340 may include gallium oxide. In such examples, the first precursor may be any suitable gallium-containing compound, including but not limited to gallium beta-diketonate, gallium alkoxides, gallium alkyls, gallium alkylamides, gallium halides, and gallium alkyls. For example, the gallium precursor may include gallium (III) acetylacetonate, dimethyl gallium isopropoxide, gallium chloride, trimethyl gallium (TMGa), tris (dimethylamino) gallium (TDMAGa), and / or triethyl gallium (TEGa).

[0036] In various examples, forming the first oxide layer 340 may further include providing a first oxygen substance to the reaction chamber (step 406). The first oxygen substance may be provided to the substrate through a showerhead, or provided through a cross-flow fluid distribution system. The first oxygen substance may be pulsed into the reaction chamber for any suitable duration (e.g., a pulse time between 0.05 and 100 seconds). In various examples, the first oxygen substance may be continuously provided to the reaction chamber 4. During the provision of the first oxygen substance, the pressure in the reaction chamber may be any suitable pressure, such as between 1 and 50 Torr. In various embodiments, the first oxygen substance may include any suitable compound including oxygen and / or an oxidizing compound, such as water (H2O), ozone (O3), hydrogen peroxide (H2O2), deuterium oxide (D2O), nitrous oxide (N2O), nitrogen dioxide (NO2) and / or an alcohol (e.g., tert-butyl alcohol), etc. or a combination thereof.

[0037] The temperature during the step of forming the first oxide layer may be between about 125°C and 300°C, or about 200°C, or between about 250°C and 450°C, or about 350°C, or between about 350°C and 500°C, or about 450°C ("about" herein means ±50°C).

[0038] The steps of providing a first precursor (step 404) and providing a first oxygen species (step 406) can be performed in any suitable order. In various examples, the first precursor can be provided to the reaction chamber 4 before the first oxygen species. In other examples, the first oxygen species can be provided to the reaction chamber 4 before the first precursor. In various examples, the step of providing a first precursor (step 404) and / or the step of providing a first oxygen species (step 406) can be repeated any suitable number of times before subsequent steps occur. For example, providing a first precursor (step 404) can be repeated multiple times before or after providing the first oxygen species (step 406) to the reaction chamber, and / or providing the first oxygen species (step 406) can be repeated multiple times before or after providing the first precursor (step 404).

[0039] In various examples, the steps of providing the first precursor (step 404) and providing the first oxygen species (step 406) can be separated by a purge gas. Thus, after providing the first precursor (step 404) to the reaction chamber 4, a purge gas (step 418) can be provided to the reaction chamber 4 to remove excess precursor, byproducts, or other unwanted materials. In an example where the first oxygen species is provided to the reaction chamber 4 before the first precursor, the purge gas can be provided to the reaction chamber 4 (step 418) after providing the first oxygen species (step 406). In various examples, a purge gas (step 418) can be provided after each step (e.g., after providing the first precursor and providing the first oxygen species, regardless of the order) and / or after depositing the first oxide layer 340 or after the first oxide deposition cycle 410 (i.e., a post-deposition purge step). The purge gas can include any suitable gas, such as an inert or non-reactive gas, such as helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe) and / or nitrogen (N2).

[0040] Steps 404 and 406, as well as any other steps involved in forming the first oxide layer 340, including the purge step 418 (collectively referred to as “first oxide deposition cycle 410”), may be repeated any suitable number of times to achieve a desired thickness of the first oxide layer 340 on the substrate 330. For example, the first oxide deposition cycle 410 may be repeated until the thickness of the first oxide layer 340 comprising zinc or gallium, or a combination thereof, is between about 0.5 and 20 angstroms thick, or about 18 angstroms thick, or between about 1 and 16 angstroms, or about 14 angstroms thick, or between about 1 and 12 angstroms thick, or about 10 angstroms thick, or between about 1 and 8 angstroms, or about 6 angstroms thick, or between about 1 and 5 angstroms thick, or about 3 angstroms thick (“about” herein means ±2 angstroms), or any other suitable thickness.

[0041] In various examples, method 400 may further include forming a second oxide layer 353 on an outer surface of first oxide layer 340 (step 416). Second oxide layer 353 may be a capping layer and / or a protective layer and may be configured to shield or seal first oxide layer 340 from a surrounding fluid (e.g., oxygen in the surrounding air) to minimize exposure of first oxide layer 340 to the surrounding fluid.

[0042] In one example, forming the second oxide layer 353 may include providing a second precursor to the reaction chamber 4 after forming the first oxide layer 340 (step 412). The second precursor may be provided to the substrate 330 from one or more reactant sources 10, 12 and / or 13 through a showerhead 8, or provided by a cross-flow fluid distribution system. The second precursor may be pulsed into the reaction chamber for any suitable duration (e.g., a pulse time between 0.05 and 100 seconds). The pulse may be repeated any suitable number of times to obtain the desired thickness of the second oxide layer 353. During the provision of the second precursor, the pressure in the reaction chamber may be any suitable pressure, such as between 1 and 50 Torr.

[0043] In various examples, forming the second oxide layer 353 may include providing a second oxygen substance to the reaction chamber (step 420). The second oxygen substance may be provided to the substrate 330 through the showerhead 8, or provided through a cross-flow fluid distribution system. The second oxygen substance may be the same as or different from the first oxygen substance. The second oxygen substance may be pulsed into the reaction chamber for any suitable duration (e.g., a pulse time between 0.05 and 100 seconds). During the provision of the second oxygen substance, the pressure within the reaction chamber may be any suitable pressure, such as between 1 and 50 Torr.

[0044] In various examples, the second oxide layer 353 may cover an outer surface of the first oxide layer 340 (i.e., a surface opposite to the substrate 330) so that the outer surface of the first oxide layer 340 is not exposed to the surrounding fluid (e.g., oxygen in the surrounding air) (e.g., Figure 3 350 of the device structure 300 shown. In various examples, the second oxide layer 353 can encapsulate the entire first oxide layer 340 (e.g., the outer surface and side surfaces of the first oxide layer). In such an example, the first oxide layer can be surrounded by the second oxide layer 353 and the substrate 330. Therefore, the second oxide layer 353 can be configured to seal at least a portion of the first oxide layer from exposure to the surrounding fluid.

[0045] In one example, the second oxide layer 353 may include any suitable compound and / or material. In various examples, the second oxide layer 353 may include an oxide layer and / or a metal oxide layer. For example, the second oxide layer 353 may include aluminum oxide (i.e., an aluminum oxide layer may be disposed on a zinc oxide or gallium oxide layer as a capping and / or protective layer).

[0046] Conventionally, the use of an aluminum-containing precursor, trimethylaluminum (TMA), to deposit aluminum oxide on zinc oxide or gallium oxide may have a deleterious effect on the underlying zinc oxide or gallium oxide (e.g., etching of the zinc oxide or gallium oxide). Without being bound by any particular theory, it is believed that TMA transfers a methyl group to the Zn or Ga present in the first oxide layer, forming a volatile ZnMe2 or GaMe2 compound. To avoid damaging the first oxide layer 340, an aluminum-containing precursor may be selected as the second precursor (in step 412) to avoid etching of the first oxide layer (e.g., by volatilization of Zn or Ga).

[0047] In such an example, the second precursor selected to avoid or minimize damage to the first oxide layer may include an aluminum-containing precursor of the formula AlRxLy, wherein R is an alkyl ligand, L is a ligand selected from an alkoxide, a dialkylamido or an amidine group, and wherein x+y=3 and y>0. In one example, the group R may include any branched or unbranched alkyl group containing 1-6 carbon atoms. In one example, the substituents attached to the atom bonded to aluminum on the L ligand may independently include any hydrocarbon group containing 1-10 carbon atoms, including branched, unbranched, cyclic and aromatic variants. In one example, the L ligand includes a nitrogen (N) atom or an oxygen (O) atom or a combination thereof bonded to an aluminum (Al) atom, such that the L ligand is bonded to the Al atom through two different atoms (e.g., attached through a carbon atom and an N or O atom or a combination thereof).

[0048] In some examples, the second precursor including an aluminum precursor may be a dimer (ie, each molecule has two aluminum atoms). In such examples, the second precursor (including an aluminum precursor) may have a chemical formula of Al2RxLy, where x+y=6 and y>0.

[0049] In one example, the R ligand of the second precursor 412 having the chemical formula AlRxLy may include alkyl ligands including, but not limited to, methyl, ethyl, 1-propyl, isopropyl, 1-butyl, isobutyl, 2-butyl, and tert-butyl.

[0050] In one example, the L ligand of the second precursor 412 having the chemical formula AlRxLy may include an alkoxide ligand, including but not limited to methoxide, ethoxide, 1-propoxide, isopropoxide, 1-butoxide, 2-butoxide, isobutoxide, tert-butoxide, 1-pentoxide, 2-pentoxide, 3-pentoxide, isopentoxide, tert-pentoxide, and neopentoxide.

[0051] In one example, the L ligand of the second precursor 412 having the chemical formula AlRxLy may include a dialkylamido ligand, including but not limited to dimethylamino, ethylmethylamido, and diethylamido.

[0052] In one example, the L ligand of the second precursor 412 having the chemical formula AlRxLy may include an amidine ligand, including but not limited to N,N'-diisopropylacetamidoyl, N,N'-di-tert-butylacetamidoyl, N,N'-diisopropylformamidoyl, and N,N'-di-tert-butylformamidoyl.

[0053] In one example, the L ligand can include a hydrocarbon group containing 1 to 10 carbon atoms, which is coupled to an L ligand substituent that is bonded to an atom that is also bonded to an aluminum atom of an aluminum precursor. The hydrocarbon group can be branched, unbranched, cyclic or aromatic, or a combination thereof. The examples of R and L ligands mentioned are for illustrative purposes and should not be considered to limit the scope of possible ligands in each type.

[0054] In various examples, forming the second oxide layer may further include providing a second oxygen substance to the reaction chamber (step 420). The second oxygen substance may be the same as or different from the first oxygen substance. The second oxygen substance may be provided to the substrate 330 through a showerhead 8, or provided through a cross-flow fluid distribution system. In various examples, the second oxygen substance may be continuously provided to the reaction chamber. In various examples, the second oxygen substance may include any suitable compound including oxygen and / or an oxidizing compound, such as water (H2O), ozone (O3), hydrogen peroxide (H2O2), deuterium oxide (D2O), nitrous oxide (N2O), nitrogen dioxide (NO2) and / or an alcohol (e.g., tert-butyl alcohol), etc. or a combination thereof.

[0055] The temperature during the step of forming the second oxide layer may be between about 125°C and 300°C, or about 200°C, or between about 250°C and 450°C, or about 350°C, or between about 350°C and 500°C, or about 450°C ("about" herein means ±50°C).

[0056] The steps of providing a second precursor (step 412) and providing a second oxygen species (step 420) may be performed in any suitable order. In various examples, the second precursor may be provided to the reaction chamber before the second oxygen species. In other examples, the second oxygen species may be provided to the reaction chamber before the second precursor. In some examples, the step of providing a second precursor (step 412) and / or the step of providing a second oxygen species (step 420) may be repeated any suitable number of times before a subsequent step occurs. For example, providing a second precursor (step 412) may be repeated multiple times before or after providing the second oxygen species (step 420) to the reaction chamber, and / or providing the second oxygen species (step 420) may be repeated multiple times before or after providing the second precursor (step 412).

[0057] In various examples, the steps of providing the second precursor and providing the second oxygen species can be separated by a purge gas (step 418). Thus, after providing the second precursor to the reaction chamber (step 412), a purge gas can be provided to the reaction chamber (step 418) to remove excess precursor, byproducts, or other unwanted materials. In examples where the second oxygen species is provided to the reaction chamber before the second precursor, the purge gas can be provided to the reaction chamber (step 418) after providing the second oxygen species (step 420). In various examples, a purge gas (step 418) can be provided after each step (e.g., after providing the second precursor and providing the second oxygen species, regardless of the order) and / or after depositing the second oxide layer 353 or after the second oxide deposition cycle (i.e., a post-deposition purge step). The purge gas can include any suitable gas, such as an inert or non-reactive gas, such as helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe) and / or nitrogen (N2).

[0058] Steps 412 and 420, as well as any other steps involved in forming the second oxide layer 353, including the purge step (collectively referred to as “second oxide deposition cycle 422”), may be repeated any suitable number of times to achieve a desired thickness of the second oxide layer 353 on the substrate 330. For example, the second oxide deposition cycle 422 may be repeated until the second oxide layer has a thickness between about 1 and 30 angstroms thick, or between about 28 angstroms thick, or between about 2 and 26 angstroms thick, or between about 24 angstroms thick, or between about 2.5 and 22 angstroms thick, or between about 20 angstroms thick, or between about 2.5 and 18 angstroms thick, or about 16 angstroms thick, or between about 2.5 and 14 angstroms thick, or about 12 angstroms thick, or between about 2.5 and 10 angstroms thick, or about 8 angstroms thick, or between about 2.5 and 6 angstroms thick, or about 4 angstroms thick (“about” herein means ±2 angstroms), or any other suitable thickness.

[0059] In various embodiments, the substrate can remain in a single reaction chamber for one or more of the processing steps discussed herein, or the substrate can be moved between reaction chambers for different processing steps. For example, substrate 330 can remain in a single reaction chamber for a first oxide deposition cycle and a second oxide deposition cycle. As another example, the first oxide deposition cycle can be performed in a first chamber and the second oxide deposition cycle can be performed in a second (different) chamber, and the claimed subject matter is not limited in this regard.

[0060] In various examples, forming the second oxide layer 353 may include first providing a second precursor and subsequently providing a third precursor to one or more reaction chambers.

[0061] Figure 5 Depicts depositing layers on a substrate to form Figure 65. The method 500 of the device structure 600 is shown. In the structure 600, the second oxide layer 353 may include a first thickness 602 and a second thickness 604. The first thickness 602 may be formed by providing a second precursor (step 412) during the second oxide deposition cycle 422 (as described above with reference to FIG. 5). Figure 4 The second thickness 604 may be formed by performing a third oxide deposition cycle 502 by providing a third precursor to the reaction chamber.

[0062] Combined with reference Figure 1 , 5 , 6 and 7, the method 500 may begin by providing a substrate 330 in a reaction chamber 4 (step 402).

[0063] In various examples, the first oxide layer 340 can be formed by a first oxide deposition cycle 410 (step 408) including steps 404, 406, and 418, as described above with reference to Figure 4 As described in method 400.

[0064] In some examples, the second oxide layer 653 may include a first thickness 602 formed by a second oxide deposition cycle 422 including steps 412, 420, and 418, as described above with reference to Figure 4 The first thickness 602 of the second oxide layer 653 (step 416) can be formed on the outer surface 702 (see FIG. 4) of the first oxide layer 340. Figure 7 ). The first thickness 602 of the second oxide layer 653 may be a covering layer and / or a protective layer, and may be configured to cover, shield, and / or seal the first oxide layer 340 from the surrounding fluid to minimize exposure of the first oxide layer 340 to various substances in the surrounding air, thereby reducing the risk of damaging the outer surface 702.

[0065] When the desired thickness of the first thickness 602 is reached, the third oxide deposition cycle 502 can start at step 504 and provide a third precursor to the reaction chamber 4 (step 504). The third precursor can be provided to the substrate 330 from one or more reactant sources 10, 12 and / or 13 through the showerhead 8, or provided by a cross-flow fluid distribution system. The third precursor can be different from the second precursor and can be pulsed into the reaction chamber for any suitable duration (e.g., a pulse time between 0.05 and 50 seconds). The pulse can be repeated any suitable number of times to achieve the desired thickness of the second thickness 604 of the second oxide layer 653. During the provision of the third precursor, the pressure in the reaction chamber 4 can be any suitable pressure, such as between 1 and 50 Torr.

[0066] In various examples, the second thickness 604 can be formed on the first thickness 602 of the second oxide layer 653, forming an upper portion of the second oxide layer 653. In one example, the second thickness 604 of the second oxide layer 653 can include any suitable compound and / or material, and can include the same or similar material as the first thickness 602. In various examples, the second thickness 604 can include an oxide layer and / or a metal oxide layer. For example, the second thickness 604 can include aluminum oxide.

[0067] In one example, the third precursor may be trimethylaluminum (TMA). The formation of the first thickness 602 may reduce the destructive effect of TMA on the underlying first oxide layer 340 containing zinc or gallium. Without being bound by any particular theory, it is believed that the first thickness 602 may form a capping or protective layer and may prevent TMA from contacting the first oxide layer 340 and volatilizing Zn or Ga.

[0068] In various examples, forming the second thickness 604 of the second oxide layer 653 can further include providing a third oxygen species to the reaction chamber (step 506). The third oxygen species can be the same or different from the first and / or second oxygen species. The third oxygen species can be pulsed into the reaction chamber for any suitable duration (e.g., a pulse time between 0.05 and 50 seconds). During the provision of the third oxygen species, the pressure within the reaction chamber can be any suitable pressure, such as between 1 and 10 Torr.

[0069] The third oxygen substance can be provided to the substrate 330 through the showerhead 8, or provided through a cross-flow fluid distribution system. In various examples, the third oxygen substance can be continuously provided to the reaction chamber. In various embodiments, the third oxygen substance may include any suitable compound including oxygen and / or an oxidizing compound, such as water (H2O), ozone (O3), hydrogen peroxide (H2O2), deuterium oxide (D2O), nitrous oxide (N2O), nitrogen dioxide (NO2) and / or alcohols (e.g., tert-butyl alcohol), etc. or a combination thereof. In some examples using a second precursor and a third precursor, the third oxygen substance may include water (H2O) and / or ozone (O3).

[0070] The steps of providing a third precursor (step 504) and providing a third oxygen species (step 506) can be performed in any suitable order. In various examples, the third precursor can be provided to the reaction chamber before the third oxygen species. In other examples, the third oxygen species can be provided to the reaction chamber before the third precursor. In some examples, the step of providing a third precursor (step 504) and / or the step of providing a third oxygen species (step 506) can be repeated any suitable number of times before a subsequent step occurs. For example, providing a third precursor (step 504) can be repeated multiple times before or after providing the third oxygen species (step 506) to the reaction chamber, and / or providing the third oxygen species (step 506) can be repeated multiple times before or after providing the third precursor (step 504).

[0071] In various examples, the steps of providing a third precursor and providing a third oxygen species may be separated by a purge gas (step 418). Thus, after providing the third precursor to the reaction chamber (step 504), a purge gas may be provided to the reaction chamber (step 418) to remove excess precursor, byproducts, or other unwanted materials. In an example where the third oxygen species is provided to the reaction chamber before the third precursor, the purge gas may be provided to the reaction chamber (step 418) after providing the third oxygen species (step 506). In various examples, a purge gas (step 418) may be provided after each step (e.g., after providing the third precursor and providing the third oxygen species, regardless of the order) and / or after depositing the second thickness 604 of the second oxide layer 353 or after the third oxide deposition cycle 502 (i.e., a post-deposition purge step). The purge gas may include any suitable gas, such as an inert or non-reactive gas, such as helium (He), neon (Ne), argon (Ar), krypton (Kr), xenon (Xe), and / or nitrogen (N2).

[0072] Steps 504 and 506, as well as any other steps involved in forming the second thickness 604 of the second oxide layer 353 (including the purge step) (collectively referred to as the “third oxide deposition cycle 502”), can be repeated any suitable number of times to achieve the desired thickness of the second thickness 604 of the second oxide layer 653. For example, the third oxide deposition cycle 502 can be repeated until the second thickness 604 of the second oxide layer 653 is between about 0.5 and 20 angstroms thick, or about 18 angstroms thick, or between about 1 and 16 angstroms thick, or about 14 angstroms thick, or between about 1 and 12 angstroms thick, or about 10 angstroms thick, or between about 1 and 8 angstroms thick, or about 6 angstroms thick, or between about 1 and 5 angstroms thick, or about 3 angstroms thick (“about” herein means ±2 angstroms), or any other suitable thickness.

[0073] In various examples, for one or more processing steps discussed herein, the substrate 330 can be maintained in a single reaction chamber (e.g., chamber 4), or can be moved between reaction chambers for different processing steps. For example, for the first oxide deposition cycle 410, the second oxide deposition cycle 422, and the third oxide deposition cycle 502, the substrate 330 can be maintained in a single reaction chamber. In another example, no more than two of the first oxide deposition cycle 410, the second oxide deposition cycle 422, and the third oxide deposition cycle 502 can be performed in the same reaction chamber. In another example, the first oxide deposition cycle 410, the second oxide deposition cycle 422, and the third oxide deposition cycle 502 can each be performed on the substrate 330 in a different reaction chamber. Similarly, one or more processing steps of the first oxide deposition cycle 410, the second oxide deposition cycle 422, and / or the third oxide deposition cycle 502 can be performed in different chambers. The claimed subject matter is not limited thereto. In various examples, the first oxide deposition cycle 410, the second oxide deposition cycle 422, and the third oxide deposition cycle 502 can be separated by a purge gas (step 418).

[0074] Although exemplary examples of the present disclosure are described herein, it should be understood that the present disclosure is not limited thereto. Various modifications, changes and enhancements may be made to the systems and methods described herein without departing from the spirit and scope of the present disclosure.

[0075] The subject matter of the present disclosure includes all novel and nonobvious combinations and subcombinations of the various systems, components and configurations, and other features, functions, acts, and / or properties disclosed herein, as well as any and all equivalents thereof.

Claims

1. A method for depositing one or more metal oxide layers on a substrate, comprising: a) providing a substrate in a reaction chamber; b) flowing a first precursor comprising zinc or gallium or a combination thereof and an oxygen species into the chamber to deposit a first oxide layer on the top surface of the substrate; c) flowing a second precursor into the chamber to deposit a second oxide layer on the first oxide layer, wherein the second precursor comprises aluminum having at least one R ligand and at least one L ligand, wherein the R ligand is an alkyl ligand, and wherein the R ligand and the L ligand are different; and Step b) or c) or a combination thereof is repeated until a desired thickness of the first oxide layer or the second oxide layer or a combination thereof is achieved.

2. The method according to claim 1, wherein: The first precursor may include one or more of an alkyl zinc, a zinc halide, a β-diketonate zinc, an alkoxy zinc, and an alkyl amide zinc.

3. The method according to claim 1, wherein: The first precursor is selected from diethylzinc (DEZ), dimethylzinc (DMZ) and zinc acetylacetonate (Zn(acac)2).

4. The method according to claim 1, wherein: The first precursor may include one or more of gallium beta diketonate, gallium alkoxide, gallium alkyl, gallium alkyl amide, gallium halide, and gallium alkane.

5. The method according to claim 1, wherein: The first precursor is selected from gallium (III) acetylacetonate, dimethylgallium isopropoxide, gallium chloride, trimethylgallium (TMGa), tris(dimethylamino)gallium (TDMAGa) and triethylgallium (TEGa).

6. The method according to claim 1, wherein: The second precursor chemical formula is AlRxLy, wherein x+y=3, or wherein the second precursor chemical formula is Al2RxLy, wherein x+y=6.

7. The method according to claim 6, wherein: At least one R ligand comprises a branched or unbranched alkyl group containing from 1 to 6 carbon atoms.

8. The method according to claim 6, wherein: At least one L ligand is an alkoxide, a dialkylamido or an amidine group.

9. The method according to claim 8, wherein: The alkoxide L ligand is selected from the group consisting of methoxide, ethoxide, 1-propoxide, isopropoxide, 1-butoxide, 2-butoxide, isobutoxide, tert-butoxide, 1-pentoxide, 2-pentoxide, 3-pentoxide, isopentoxide, tert-pentoxide and neopentoxide.

10. The method according to claim 8, wherein: The dialkylamido L ligand is selected from the group consisting of dimethylamino, ethylmethylamido and diethylamido.

11. The method according to claim 8, wherein: The amidino L ligand is selected from N,N'-diisopropylacetamidino, N,N'-di-tert-butylacetamidino, N,N'-diisopropylformamidino and N,N'-di-tert-butylformamidino.

12. The method according to claim 8, wherein: At least one of the one or more L ligands comprises a hydrocarbon group comprising 1 to 10 carbon atoms and one nitrogen (N) atom or oxygen (O) atom or a combination thereof bonded to an aluminum (Al) atom, wherein the L ligand is bonded to the Al atom through two different atoms.

13. The method according to claim 12, wherein: The hydrocarbyl group is branched, unbranched, cyclic or aromatic, or a combination thereof.

14. The method according to claim 1, wherein: The first oxide layer has a thickness between 0.5 and 20 angstroms thick.

15. The method according to claim 1, wherein: The first oxide layer is a zinc oxide layer.

16. The method according to claim 15, wherein: The zinc oxide layer includes zinc oxide, aluminum-doped zinc oxide, indium gallium zinc oxide, or a combination thereof.

17. The method according to claim 1, wherein: The first oxide layer is a gallium oxide layer.

18. The method according to claim 17, wherein: The gallium oxide layer includes gallium oxide (GaO), indium gallium oxide (IGO), gallium zinc oxide (GaZnO) or indium gallium zinc oxide (IGZO) or a combination thereof.

19. The method according to claim 1, wherein: A second oxide layer of a first thickness is deposited using the second precursor, and a second oxide layer of a second thickness is deposited using a third precursor, wherein the second precursor is different from the third precursor.

20. The method according to claim 19, wherein: The second oxide layer is aluminum oxide.

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