Method, system and apparatus for treating substrate surface

Abstract

A method of depositing one or more layers on a substrate is disclosed. The method may include providing a substrate, etching a natural oxide from a surface of the substrate in response to exposure to an etchant, contacting the etched surface of the substrate with an oxidant, oxidizing a first layer of the substrate in response to contact with the oxidant, and depositing a second layer on the first layer.

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 more particularly to substrate surface processing for defect reduction. Background Art

[0002] The scaling down 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, manufacturing increasingly complex structures for future technology nodes while striving to maintain or improve yields is a huge challenge. Nucleation delays in thin film deposition not only reduce yields, but also introduce defects in device layers that can cause device failures, thereby exacerbating this challenge. Therefore, there is a continuing need to mitigate nucleation delays.

[0003] One reason for nucleation delay may be the removal of native oxide from the surface of Si and SiGe substrates. Due to exposure of the substrate to oxygen during integrated circuit manufacturing, such as exposure to ambient air during transfer of the substrate between manufacturing systems, or residual oxidants in the manufacturing system, native oxide materials may be formed on the substrate surface. Native oxides generally lack uniformity and are full of defects. Therefore, before film deposition, the native oxide layer will be removed (e.g., by etching with hydrogen fluoride (HF)). However, after removing the native oxide, the surface of the substrate may be hydrogen terminated. In this way, hydrogen termination (e.g., Si-H) may be inert, resulting in delayed nucleation of subsequent deposited films, and may further produce island-type film growth rather than smooth 2D-type film growth. Where the islands merge, as the film becomes thicker, the boundaries formed by the merged grains may have weaker physical properties, such as the merged boundaries may be easier to etch, or may be more likely to become current leakage paths.

[0004] Traditional methods to address this nucleation delay and island growth use wet bench methods (such as ozone water or RCA-1 cleaning), which increases throughput delays because the wet bench module is not integrated with the reaction chamber where film deposition will subsequently occur.

[0005] Such systems and methods for mitigating nucleation delay are generally considered suitable for their intended purpose. However, there remains a need in the art for improved methods of reducing nucleation delay. The present disclosure provides a solution to this need. Summary of the invention

[0006] 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.

[0007] In one aspect, a method of depositing one or more layers on a substrate is disclosed. The method may include providing a substrate, etching a native oxide from a surface of the substrate in response to exposure to an etchant, contacting the etched surface of the substrate with an oxidant, oxidizing a first layer of the substrate in response to contact with the oxidant, and depositing a second layer on the first layer.

[0008] In some examples, the etchant may be a gas phase chemical. Alternatively, the etchant may be a liquid phase chemical. The etchant may include hydrogen chloride (HCl), hydrogen fluoride (HF), ammonium hydroxide (NH4OH) or hydrogen (H2) or a combination thereof. The substrate may include silicon (Si), germanium (Ge) or silicon germanium (SiGe).

[0009] In some examples, the oxidant may include an oxidant weaker than ozone (O3). The oxidant may include H2O2 and / or may contact the substrate in a gas phase. Oxidizing the first layer of the substrate may also include oxidizing the substrate to a depth of less than 10 angstroms relative to the top surface of the substrate.

[0010] In some examples, oxidizing the first layer of the substrate may further include oxidizing the substrate to a depth of less than 5 angstroms relative to a top surface of the substrate. Oxidizing the first layer of the substrate may further include hydroxylating a portion of molecules at the etched surface of the substrate.

[0011] In some examples, contacting the substrate surface with the oxidant may also include changing the temperature of the substrate when in contact with the oxidant based on the desired thickness of the first oxide layer. Controlling the temperature of the substrate may also include heating a pedestal (e.g., pedestal 6 or 106) coupled to substrate 30 or adjusting the temperature of the oxidant in contact with substrate 30.

[0012] In some examples, the first layer may include a first oxide layer, and wherein the second layer is a second oxide layer. The first oxide layer may include silicon oxide or silicon germanium oxide. The second oxide layer may include a metal oxide, including at least one of magnesium oxide (MgO), aluminum oxide (Al2O3), zirconium oxide (ZrO2), hafnium oxide (HfO2), hafnium silicon oxide (HfSiO), tantalum oxide (Ta2O5), tantalum silicon oxide (TaSiO), barium strontium titanate (BST), and strontium bismuth tantalate (SBT). The second oxide layer may include an oxide including at least one of scandium (Sc), yttrium (Y), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb) and lutetium (Lu), and silicon nitride (SiN).

[0013] In some examples, the second layer may be between about 0.5 and 30 angstroms thick. Contacting the etched surface of the substrate with the oxidant may also include supporting the substrate in a first reaction chamber and flowing the oxidant into the first reaction chamber. Depositing the second layer may also include depositing a second oxide layer in the first reaction chamber.

[0014] In some examples, depositing the second layer can also include depositing a second oxide layer in the second reaction chamber.

[0015] In various examples, etching native oxide from the substrate surface may further include etching native oxide in the first reaction chamber.

[0016] In other examples, etching native oxide from the substrate surface can further include etching native oxide in the second reaction chamber.

[0017] In some examples, etching native oxide from the substrate surface may further include etching native oxide in a first reaction chamber, and wherein depositing the second layer may further include depositing the second oxide layer in the first reaction chamber.

[0018] In order 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 all of these objects or advantages may not be achieved according to any specific embodiment or example of the present disclosure. Thus, for example, those skilled in the art will recognize that the examples disclosed herein can 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.

[0019] 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 through the following detailed description of certain examples with reference to the accompanying drawings, the present disclosure not being limited to any particular examples discussed. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] 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.

[0021] Figure 1A A schematic diagram of a reactor system according to an example of the present technology is shown.

[0022] Figure 1B A schematic diagram of a reactor system according to an example of the present technology is shown.

[0023] Figure 2A schematic diagram of a reactor system having multiple reaction chambers according to an example of the present technology is shown.

[0024] Figure 3 A device structure according to an example of the present technology is shown.

[0025] Figure 4 A processing method according to an example of the present technology is shown.

[0026] Figure 5 A processing method according to an example of the present technology is shown. DETAILED DESCRIPTION

[0027] 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 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.

[0028] 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.

[0029] 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.

[0030] 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.

[0031] 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, the term "atomic layer deposition" as used herein 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).

[0032] 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.

[0033] 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.

[0034] 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.

[0035] Figure 1AA 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 a variety of applications, including depositing and / or etching materials on a substrate surface. As used herein, the term "surface" can refer to any portion of an exposed semiconductor surface. For example, the surface can be the entire exterior of a semiconductor substrate and / or layer, or a portion thereof, or the top surface of a semiconductor substrate and / or a layer thereon, or a portion thereof.

[0036] In various embodiments, reactor system 50 may include reaction chamber 4, susceptor 6 to hold substrate 30 during processing, fluid distribution system 8 (e.g., showerhead) to distribute one or more reactants to the surface of substrate 30, one or more reactant sources 10, 12, and / or 13, and / or carrier and / or purge gas source 14, which are fluidly coupled to reaction chamber 4 through corresponding lines 16, 18, 19, and 20 and corresponding valves or controllers 22, 24, 25, and 26. Reactant gas or other material from reactant sources 10, 12, and / or 13 may be applied to substrate 30 in reaction chamber 4. Purge gas from purge gas source 14 may flow to and through reaction chamber 4 to remove any excess reactant or other undesirable material from reaction chamber 4. System 50 may also include vacuum source 28 fluidly coupled to reaction chamber 4, which may be configured to exhaust reactants, purge gas, or other material out of reaction chamber 4.

[0037] Controller 52 may be configured to perform various functions and / or steps as described herein. Controller 52 may include one or more microprocessors, memory elements, and / or switching elements to perform various functions. Although illustrated as a single unit, controller 52 may alternatively include multiple devices. For example, controller 52 may be used to control airflow (e.g., by monitoring flow and controlling valves 22, 24, 25, and / or 26), motors, heaters, cooling devices, and / or vacuum source 28 to perform various processes (e.g., Figure 4 Method 400 and / or Figure 5 In addition, when the system includes two or more reaction chambers, as described in more detail below, the two or more reaction chambers can be coupled to the same / shared controller.

[0038] In one example, substrate 30 may include Si or SiGe and may have a layer of native oxide on the top surface. In some examples, surface 31 may be prepared for subsequent surface treatment by removing the native oxide from top surface 31. Such cleaning may be performed before loading substrate 30 into reaction chamber 4. For example, an ex-situ process for removing native oxide may be performed using wet chemical cleaning, such as with a dilute hydrogen fluoride solution (HF and deionized water).

[0039] In another example, a cleaning process may be performed after the substrate 30 is loaded into the reaction chamber 4 in an in-situ process. In such an example, the reactor system 50 may be configured to perform a cleaning process to etch and / or otherwise remove native oxides. Thus, the reactant source 10 may include an etchant, such as a chemical 11, which includes solid, liquid, and / or gas phase chemicals to clean the surface 31 of the substrate 30 prior to deposition. For example, the chemical 11 may include a chemical that is capable of removing native oxides from the surface 31 by contacting the surface 31. As non-limiting examples, such chemical 11 may include, but is not limited to, hydrogen chloride (HCl), hydrogen fluoride (HF), ammonium hydroxide (NH4OH), hydrogen (H2), and hydrogen plasma.

[0040] In one example, after the native oxide is removed, the surface 31 may be hydrogen terminated. Such hydrogen termination may result in delayed nucleation and island formation during deposition of subsequent films on the surface 31. The surface treatment may be applied to replace the terminal hydrogen attached to the surface 31 with hydroxyl groups (i.e., to couple hydroxyl (OH) groups to molecules at the surface 31). The reactor system 50 may be configured to perform such a surface treatment. Alternatively, the surface treatment to hydroxylate the surface 31 of the substrate 30 may be performed in a different reaction chamber, such as Figure 1B Reaction chamber 104 is shown.

[0041] Reference now Figure 1B In various examples, the reactor system 150 may include a reaction chamber 104, a pedestal 106 that holds the substrate 30 during processing, a fluid distribution system 108 (e.g., a showerhead) that distributes one or more reactants to the surface of the substrate 30, one or more reactant sources 110, 112, and / or 113, and / or a carrier gas and / or purge gas source 114, which are fluidly coupled to the reaction chamber 104 through corresponding lines 116, 118, 119, and 120 and corresponding valves or controllers 122, 124, 125, and 126. Reactant gases (e.g., oxidants 115, precursors 117, and / or oxygen species 121) or other materials from the sources 110, 112, and / or 113 may be applied to the substrate 30 in the reaction chamber 104. Purge gas 123 from gas source 114 may flow to and through the reaction chamber 104 to remove any excess reactants or other undesirable substances from the reaction chamber 104. The system 150 may also include a vacuum source 128 fluidly coupled to the reaction chamber 104 , which may be configured to evacuate reactants, purge gases, or other materials from the reaction chamber 104 .

[0042] Controller 152 may be configured to perform various functions and / or steps as described herein. Controller 152 may include one or more microprocessors, memory elements, and / or switching elements to perform various functions. Although illustrated as a single unit, controller 152 may alternatively include multiple devices. For example, controller 152 may be used to control airflow (e.g., by monitoring flow and controlling valves 122, 124, 125, and / or 126), motors, heaters, cooling devices, and / or vacuum source 128 to perform various processes (e.g., Figure 4 Method 400 and / or Figure 5 In addition, when the system includes two or more reaction chambers, as described in more detail below, the two or more reaction chambers can be coupled to the same / shared controller.

[0043] In one example, the surface treatment of the oxidized surface 31 can include pulsing an oxidant 115 (e.g., H2O2 vapor) from a reactant source 110 to the reaction chamber 104 via a showerhead 108. The oxidant 115 can contact the surface 31 of the substrate 30 to oxidize the surface of the substrate 30 and replace hydrogen with OH groups on the surface molecules terminated with hydrogen. This can reduce nucleation delays in subsequent oxide formation. In addition, the consumption of substrate 30Si and / or SiGe can be minimized because H2O2 is a relatively weak oxidant. Therefore, the surface oxide thickness can be minimized. Using this method, the surface oxide thickness can be limited to less than or equal to about 4 angstroms.

[0044] After forming the first oxide layer on substrate 30 by treatment with oxidant 115 , the second oxide layer deposited on surface 31 may have reduced nucleation delay and island formation, resulting in smoother and faster closing and a more uniform surface film.

[0045] In one example, the first and second oxide layers can be deposited in the same chamber, or can be deposited in different chambers. The second oxide layer can be formed by any of a variety of methods known to those skilled in the art. For example, forming the second oxide layer can include providing a precursor 117 and / or an oxygen source 121 to the reaction chamber 104 through the showerhead 108 to the substrate 30, and purging the chamber 104 with a purge gas 123 at different time intervals.

[0046] In some examples, a reactor system (e.g., reactor system 50 or reactor system 150) can include multiple reaction chambers. Figure 2 In the reactor system 200 shown, a plurality of reaction chambers 204 (each reaction chamber may be a Figure 1A and 1BThe load lock chamber 212 and the reaction chamber 204 may be disposed around and / or coupled to a transfer chamber 280 including 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., through the transfer chamber 280). For example, for different steps of the semiconductor manufacturing process, the substrate 30 may be disposed in different chambers (e.g., etching, oxidation, passivation, and / or deposition steps may each be performed in the same or different chambers).

[0047] Figure 3 A structure 300 according to an example of the present disclosure is shown. The device structure 300 can be any of a variety of semiconductor structures. The structure 300 includes a substrate 30 (e.g., Si or SiGe), a first oxide layer 340 including an oxide (e.g., silicon oxide (SiOx) or silicon germanium oxide (SiGeOx)), and a second oxide layer 350 (e.g., a metal oxide or a lanthanide oxide). The first oxide layer 340 can be located on the top surface 31 of the substrate 30. In an example, the second layer 350 can be located on the first oxide layer 340. The structure 300 can be formed according to the examples described herein.

[0048] Figure 4 An example process 400 for forming structure 300 according to an example of the present disclosure is shown. Figure 1A , 1B , 3 and 4, the method 400 may include in a reaction chamber (e.g. Figure 1A A substrate 30 is provided in a reaction chamber 4 in the reactor. The substrate 30 may be disposed on a base (e.g. Figure 1A on a base 6) in the for processing.

[0049] In one example, process 400 may begin at operation 430 by providing substrate 30 within a chamber (eg, chamber 4 or chamber 104 ).

[0050] The process 400 may move to operation 432, where an etchant such as chemical 11 (e.g., HF, HCl, NH4OH, and / or H2) may flow into the chamber to contact the top surface 31 of the substrate 30. Chemical 11 may be a liquid or a gas, and may include any of a variety of etchants known to those skilled in the art. Chemical 11 may be configured to remove native oxide 433 formed on the surface 31 by etching. Etching the native oxide 433 from the surface 31 may leave a hydrogen-terminated surface 31. Such hydrogen termination tends to be less reactive or inert, and may result in nucleation delays in subsequent oxide layer formation.

[0051] The process 400 may proceed to operation 434, where the oxidant 115 may flow into the chamber to contact the surface 31. Operation 434 may occur in the same or different chamber (e.g., chamber 4 or chamber 104) as operation 432. The first oxide layer 340 may be formed by oxidizing the surface 31 of the substrate 30. In an example, the oxidant 115 may include an oxidant that is weaker than O3 (e.g., H2O2). Compared to conventional methods, the process 400 disclosed herein includes depositing the first oxide layer 340 using a relatively weak oxidant (e.g., H2O2) to minimize the consumption of Si and / or SiGe, thereby minimizing the thickness of the first oxide layer 340. The use of a weak oxidant may facilitate control of the diffusion of the oxidant into the substrate 30, enabling the formation of a thin first oxide layer 340. In addition, by controlling the temperature of the oxidant 115, the thickness 416 of the first oxide layer 340 may be constrained. Therefore, the temperature of the oxidant and / or the substrate 30 may be changed before or while the oxidant 115 contacts the substrate 30 based on the desired thickness of the first oxide layer 340. In an example, the temperature of the oxidant 115 can be controlled by controlling the temperature of the substrate 30 and / or by controlling the temperature of the oxidant 115. The temperature of the substrate 30 can be controlled within the chamber 4 or 104 by controlling the temperature of the susceptor 6 or 106. In an example, contacting the surface 31 of the substrate 30 with the oxidant 115 can include changing the temperature of the substrate 30 when in contact with the oxidant 115 to control the thickness of the first oxide layer 340 in real time, such as by controlling the temperature of the susceptor (e.g., the susceptor 6 or 106) or adjusting the temperature of the oxidant 115 contacting the substrate.

[0052] In one example, using a weak oxidant such as H2O2 vapor as the oxidant 115 can produce a first oxide layer 340 having abundant OH groups at the surface (e.g., surface 353) by hydroxylating a portion of the molecules on the etched surface 31. Replacing the hydrogen-terminated surface left by etching the native oxide 433 from the surface 31 with OH groups can reduce nucleation delays in subsequent oxide layer formation.

[0053] In one example, the first oxide layer 340 can be formed to have a thickness 416 in the following range: about 0.1 to 20 angstroms or about 18 angstroms, or between about 0.5 to 16 angstroms or about 14 angstroms, or between about 1 to 12 angstroms or about 10 angstroms, or between about 1 to 8 angstroms or about 6 angstroms, or between about 1 to 6 angstroms or about 4 angstroms ("about" means ±2 angstroms in this document), or any other suitable thickness. In some examples, the thickness 416 of the first oxide layer 340 is less than or equal to 5 angstroms.

[0054] In some embodiments, contacting the substrate 30 with the oxidant 115 may include pulsing the oxidant 115 into the reaction chamber and then contacting the substrate 30 for a period of time between about 0.01 seconds and about 60 seconds, or between about 0.01 seconds and about 50 seconds, or between about 0.01 seconds and about 40 seconds, or between about 0.01 seconds and about 30 seconds, or between about 0.01 seconds and about 20 seconds, or between about 0.01 seconds and about 10 seconds, or between about 0.01 seconds and about 5.0 seconds ("about" means ±5 seconds herein), or any other suitable duration. The pulses may be alternating or continuous. In some embodiments, the oxidant 115 can be pulsed for about 1 cycle to about 100 cycles, or about 1 cycle to about 80 cycles, or about 1 cycle to about 60 cycles, or about 1 cycle to about 40 cycles, or about 1 cycle to about 30 cycles, or about 1 cycle to about 15 cycles ("about" herein means ±15 cycles) or any suitable number of cycles. In some embodiments, operation 434 can be pulsed for about 30 seconds for about 30 cycles.

[0055] The temperature during the step of forming the first oxide layer 340 can be between about 100°C and 500°C, or about 450°C, or between about 100°C and 400°C, or about 350°C, or between about 100°C and 300°C, or about 250°C, or between about 100°C and 200°C, or about 150°C (“about” herein means ±50°C) or any sufficient temperature.

[0056] In one example, process 400 may proceed to operation 436, where a second oxide layer 350 may be formed on first oxide layer 340. In various examples, forming second oxide layer 350 may include providing a precursor 117 and / or oxygen species 121 to a reaction chamber (e.g., reaction chamber 4 or reaction chamber 104). Precursor 117 may be provided to substrate 30 via a showerhead (e.g., showerhead 8 or showerhead 108), or provided via a cross-flow fluid distribution system. In one example, precursor 117 may be a metal-containing precursor for forming a metal oxide, including but not limited to magnesium oxide (MgO), aluminum oxide (Al2O3), zirconium oxide (ZrO2), hafnium oxide (HfO2), hafnium silicon oxide (HfSiO), tantalum oxide (Ta2O5), tantalum silicon oxide (TaSiO), barium strontium titanate (BST), and strontium bismuth tantalate (SBT). In other examples, the precursor 117 may include lanthanide oxides, oxides of physically stable "rare earth" elements, such as scandium (Sc), yttrium (Y), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (er), thulium (Tm), ytterbium (Yb), and lutetium (Lu), and silicon nitride (SiN). The precursor 117 may be pulsed into the reaction chamber for any suitable duration (e.g., a pulse time between 0.05 and 60 seconds). During the provision of the first precursor, the pressure in the reaction chamber may be any suitable pressure, such as between 1 and 10 Torr.

[0057] In various examples, forming the second oxide layer 350 may further include providing an oxygen substance 121 to the reaction chamber. The oxygen substance 121 may be provided to the substrate 30 by a showerhead (e.g., showerhead 8 or showerhead 108), or provided by a cross-flow fluid distribution system. The oxygen substance 121 may be pulsed into the reaction chamber for any suitable duration (e.g., a pulse time between 0.05 and 60 seconds). In various examples, the oxygen substance may be continuously provided to the reaction chamber. The pressure in the reaction chamber during the provision of the oxygen substance may be any suitable pressure, such as between 1 and 10 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 alcohols (e.g., tert-butyl alcohol), etc. or a combination thereof.

[0058] The temperature during the step of forming the second oxide layer 350 can be between about 100°C and 500°C, or about 450°C, or between about 100°C and 400°C, or about 350°C, or between about 100°C and 300°C, or about 250°C, or between about 100°C and 200°C, or about 150°C (“about” herein means ±50°C) or any sufficient temperature.

[0059] The steps of providing the precursor 117 and providing the oxygen species 121 may be performed in any suitable order. In various examples, the steps of providing the precursor 117 and / or the oxygen species 121 may be separated by a purge gas 123 to remove excess precursor, byproducts, or other unwanted materials. In various examples, a purge gas may be provided after each step (e.g., after providing the precursor 117 and providing the oxygen species 121, regardless of order) and / or after depositing the first oxide layer 340 or after depositing the second oxide layer 350 (i.e., a post-deposition purge step).

[0060] The second oxide layer 350 can be deposited to any thickness, for example, between about 0.5 and 30 angstroms thick, or about 27 angstroms thick, or between about 1 and 24 angstroms thick, or about 21 angstroms thick, or between about 1 and 18 angstroms thick, or about 15 angstroms thick, or between about 1 and 12 angstroms thick, or about 9 angstroms thick, or between about 1 and 6 angstroms thick, or about 3 angstroms thick (“about” herein means ±3 angstroms), or any other suitable thickness.

[0061] refer to Figure 1A , 1B , 3 and 4, Figure 5 A method 500 of depositing layers on a substrate to form the device structure 300 is depicted.

[0062] In an example, method 500 may begin at operation 502, where a substrate is supported in a reaction chamber, such as reaction chamber 4 or reaction chamber 104. The substrate may include any suitable material, such as, but not limited to, silicon (Si), germanium (Ge), or silicon germanium (SiGe).

[0063] In one example, method 500 may move to operation 504, where the native oxide (e.g., native oxide 433) on surface 31 of substrate 30 may be etched in response to exposure to an etchant. The etchant may be applied as a liquid or a gas. The etchant may include any suitable etchant, such as, but not limited to, hydrogen chloride (HCl), hydrogen fluoride (HF), ammonium hydroxide (NH4OH), or hydrogen (H2), or a combination thereof. Method 500 may proceed to operation 540, where a purge gas may be provided to the reaction chamber to remove excess precursors, byproducts, or other unwanted materials. A purge gas may be provided between etchant pulses and / or when an etchant pulse is completed.

[0064] In one example, method 500 may continue to operation 506, where a first oxide layer 340 may be formed by contacting surface 31 with an oxidant 115. Oxidant 115 may diffuse from surface 31 into substrate 30 and oxidize a top layer of substrate 30 to form an oxide layer (e.g., silicon oxide (SiOx) or silicon germanium oxide (SiGeOx)). Oxidizing the top of substrate 30 forms first oxide layer 340. Oxidant 115 may be an oxidant that is weaker than ozone (O3). For example, oxidant 115 may be hydrogen peroxide (H2O2).

[0065] In one example, the oxidant 115 can contact the substrate 30 in the vapor phase to oxidize the substrate 30 to a depth less than about 10 angstroms relative to the top surface 31, or less than about 5 angstroms relative to the top surface 31 ("about" herein means ±5 angstroms) or any sufficient depth.

[0066] In one example, oxidizing the top surface 31 of the substrate 30 also includes hydroxylating a portion of the molecules at the etched surface 31 of the substrate 30. Such hydroxylated surface 31 portions are less likely to cause nucleation delays in the formation of a subsequent oxide layer by reducing island formation and / or faster film closure. This can improve the roughness of subsequent film deposition.

[0067] At operation 508, in one example, contacting the surface 31 of the substrate 30 with the oxidant 115 may further include changing the temperature of the substrate 30 and / or the oxidant 115 before, during, and / or after the oxidant 115 contacts the substrate 30. Adjusting the temperature of the substrate 30 may affect the thickness of the first oxide layer 340. Therefore, the temperature may be adjusted based on the desired thickness of the first oxide layer 340. The temperature modification may be performed by changing the temperature of a susceptor (e.g., susceptor 6 or susceptor 106) or by changing the temperature of the oxidant 115 in other ways known to those skilled in the art.

[0068] The method 500 may proceed to operation 540 where a purge gas may be provided to the reaction chamber to remove excess precursors, byproducts, or other unwanted materials. The purge gas may be provided before, between, and / or after the pulses of the oxidant 115 and / or when the oxidant pulses are completed or the formation of the first oxide layer 340 is completed.

[0069] In one example, method 500 may continue to operation 510 where second oxide layer 350 may be formed on first oxide layer 340. Forming second oxide layer 350 may include providing precursor 117 to a reaction chamber (e.g., reaction chamber 4 or reaction chamber 104) at operation 512 and / or providing oxygen species 121 at operation 514.

[0070] Operations 512 and 514 may be performed in any suitable order. Method 500 may proceed to operation 540, where a purge gas may be provided to the reaction chamber to remove excess precursor, byproducts, or other unwanted materials. The purge gas may be provided before, between, and / or after pulses of precursor 117 and / or oxygen species 121 and / or upon completion of formation of second oxide layer 350.

[0071] In various examples, purge gas 123 may be provided (operation 540) after each step (e.g., after providing precursor 117 and providing oxygen species 121, regardless of order) and / or after depositing first oxide layer 340 or after depositing second oxide layer 350 (i.e., a post-deposition purge step).

[0072] 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.

[0073] 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 layers on a substrate, comprising: a) providing a substrate; b) etching native oxide from the surface of the substrate in response to exposure to the etchant; c) contacting the etched surface of the substrate with an oxidant; d) oxidizing the first layer of the substrate in response to contact with the oxidant; as well as e) Depositing a second layer on the first layer.

2. The method according to claim 1, wherein: The etchant is a gas phase chemical.

3. The method according to claim 1, wherein: The etchant is a liquid phase chemical.

4. The method according to claim 1, wherein: The etchant may include hydrogen chloride (HCl), hydrogen fluoride (HF), ammonium hydroxide (NH 4 OH) or hydrogen (H 2 ) or a combination thereof.

5. The method according to claim 1, wherein: The substrate includes silicon (Si), germanium (Ge) or silicon germanium (SiGe).

6. The method according to claim 1, wherein: The oxidant is a weaker oxidant than ozone (O3).

7. The method according to claim 1, wherein: The oxidant is H2O2.

8. The method according to claim 7, wherein: The oxidant contacts the substrate in a gas phase.

9. The method according to claim 8, wherein: Oxidizing the first layer of the substrate further includes oxidizing the substrate to a depth less than 10 angstroms relative to a top surface of the substrate.

10. The method according to claim 8, wherein: Oxidizing the first layer of the substrate further includes oxidizing the substrate to a depth less than 5 angstroms relative to a top surface of the substrate.

11. The method according to claim 1, wherein: Oxidizing the first layer of the substrate also includes hydroxylating a portion of the molecules at the etched surface of the substrate.

12. The method according to claim 1, wherein: Contacting the substrate surface with the oxidant further includes changing a temperature of the substrate while in contact with the oxidant based on a desired thickness of the first oxide layer.

13. The method according to claim 12, wherein: Changing the substrate temperature may also include heating a susceptor coupled to the substrate or adjusting the temperature of an oxidant contacting the substrate.

14. The method according to claim 1, wherein: The first layer is a first oxide layer, and wherein the second layer is a second oxide layer.

15. The method according to claim 14, wherein: The first oxide layer is silicon oxide or silicon germanium oxide.

16. The method according to claim 14, wherein: The second oxide layer is a metal oxide including at least one of the following: magnesium oxide (MgO), aluminum oxide (Al2O3), zirconium oxide (ZrO2), hafnium oxide (HfO2), hafnium silicon oxide (HfSiO), tantalum oxide (Ta2O5), tantalum silicon oxide (TaSiO), barium strontium titanate (BST) and strontium bismuth tantalate (SBT).

17. The method according to claim 14, wherein: The second oxide layer is an oxide including at least one of the following: scandium (Sc), yttrium (Y), lanthanum (La), cerium (Ce), praseodymium (Pr), neodymium (Nd), samarium (Sm), europium (Eu), gadolinium (Gd), terbium (Tb), dysprosium (Dy), holmium (Ho), erbium (Er), thulium (Tm), ytterbium (Yb) and lutetium (Lu).

18. The method according to claim 1, wherein: The second layer has a thickness between approximately 0.5 angstroms and 30 angstroms thick.

19. The method according to claim 1, wherein: Contacting the etched surface of the substrate with an oxidant further comprises: supporting a substrate in a first reaction chamber; and An oxidant is flowed into the first reaction chamber.

20. The method according to claim 1, wherein: Depositing the second layer also includes depositing a second oxide layer in the first reaction chamber.

21. The method according to claim 19, wherein: Depositing the second layer also includes depositing a second oxide layer in the second reaction chamber.

22. The method according to claim 19, wherein: Etching native oxide from the surface of the substrate further includes etching native oxide in the first reaction chamber.

23. The method according to claim 19, wherein: Etching the native oxide from the substrate surface further includes etching the native oxide in the second reaction chamber.

24. The method according to claim 19, wherein: Etching native oxide from the substrate surface further comprises etching native oxide in a first reaction chamber, and wherein depositing the second layer further comprises depositing a second oxide layer in the first reaction chamber.

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