Methods for forming topographically selective silicon oxide film by cyclical plasma-enhanced deposition process

Abstract

To provide: methods for forming a topographically selective silicon oxide film by a cyclical plasma-enhanced deposition process; and methods of forming a silicon oxide film selectively either over horizontal surfaces of a non-planar substrate or over vertical surfaces of a non-planar substrate.SOLUTION: The methods include: forming a topographically selective silicon oxide film on a substrate by a cyclical plasma-enhanced deposition process; forming a silicon oxide film by a plasma enhanced atomic layer deposition (PEALD) process or a cyclical plasma-enhanced chemical vapor deposition (cyclical PECVD) process; and forming a silicon oxide film selectively either over horizontal surfaces of a non-planar substrate or over vertical surfaces of a non-planar substrate.SELECTED DRAWING: Figure 2

Description

[Technical field]

[0001] The present disclosure generally relates to methods for forming shape-selective silicon oxide films by cyclic plasma-enhanced deposition processes, and to specific methods for forming silicon oxide films either selectively on horizontal surfaces of non-planar substrates or selectively on vertical surfaces of non-planar substrates. The present disclosure also generally relates to shape-selective cyclic plasma-enhanced deposition processes, such as plasma-enhanced atomic layer deposition (PEALD) processes and cyclic plasma-enhanced chemical vapor deposition (PECVD) processes. [Background technology]

[0002] In the field of semiconductor device technology, silicon oxide films may be used during the fabrication of semiconductor integrated circuits. For example, silicon oxide films may be used as insulating materials during the fabrication of semiconductor device structures, such as transistors, memory cells, logic devices, memory arrays, etc.

[0003] A typical silicon oxide film deposition process may involve, for example, heating a substrate to a temperature above about 400° C. and then exposing the substrate to tetraethyl orthosilicate (TEOS) vapor to deposit a layer of silicon dioxide on the surface of the substrate. Such a typical silicon oxide film deposition method may deposit a silicon oxide film that is relatively conformal across the surface of the substrate, i.e., the silicon oxide film has a relatively uniform thickness across the shape of the substrate.

[0004] However, for next generation technology nodes, it may be beneficial to provide the ability to form silicon oxide with shape selectivity, for example, to form a silicon oxide film on a non-planar substrate surface with selectivity to a first planar surface of the non-planar substrate relative to a second planar surface of the non-planar substrate.

[0005] Thus, a method is desirable for forming shape-selective silicon oxide films, and in particular for either selectively forming silicon oxide films on horizontal surfaces of a non-planar substrate or selectively forming silicon oxide films on vertical surfaces of a non-planar substrate. Summary of the Invention [Means for solving the problem]

[0006] In accordance with at least one embodiment of the present disclosure, a method for forming a shape-selective silicon oxide film by a cyclic plasma-enhanced deposition process is provided, the method including providing a non-planar substrate having one or more horizontal surfaces and one or more vertical surfaces into a reaction chamber, contacting the non-planar substrate with a gas-phase reactant including a silicon component, a carbon component, and a hydrogen component, contacting the non-planar substrate with reactive species generated from a plasma generated from a gas including an oxygen precursor and a noble gas, and forming a silicon oxide film either selectively on the horizontal surfaces of the non-planar substrate or selectively on the vertical surfaces of the non-planar substrate.

[0007] Embodiments of the present disclosure also include a method of forming a shape-selective silicon oxide film by a cyclic plasma-enhanced deposition process, the method including providing a non-planar substrate having one or more horizontal surfaces and one or more vertical surfaces into a reaction chamber, contacting the non-planar substrate with a first reactive species generated from a first gas including at least a gas-phase reactant including a silicon component, a carbon component, and a hydrogen component, contacting the non-planar substrate with a second reactive species generated from a second gas including at least an oxygen precursor and a noble gas, and forming a silicon oxide film either selectively on the horizontal surfaces of the non-planar substrate or selectively on the vertical surfaces of the non-planar substrate.

[0008] Embodiments of the present disclosure also include a method of forming a shape-selective silicon oxide film on a non-planar substrate by a plasma-enhanced atomic layer deposition process, the method including contacting the non-planar substrate with a gas-phase reactant including a silicon component, a carbon component, and a hydrogen component, contacting the non-planar substrate with a plurality of ions including at least oxygen ions, where the plurality of ions impact the substrate in a direction substantially perpendicular to a horizontal surface of the substrate, and selectively depositing a silicon oxide film on the horizontal surfaces of the non-planar substrate relative to the vertical surfaces of the non-planar substrate.

[0009] For purposes of summarizing the invention and the advantages achieved over the prior art, certain specific objects and advantages of the invention have been described herein above. Of course, it should be understood that not all such objects or advantages may be achieved by any particular embodiment of the invention. Thus, for example, one skilled in the art will recognize that the invention may be embodied or carried out in a manner that achieves or optimizes one advantage or group of advantages as taught or suggested herein, without necessarily achieving other objects or advantages as may be taught or suggested herein.

[0010] All of these embodiments are intended to be within the scope of the invention disclosed herein. These and other embodiments will become readily apparent to those skilled in the art from the following detailed description of certain embodiments, taken in conjunction with the accompanying drawings, and the invention is not limited to any particular embodiment disclosed.

[0011] While the specification particularly points out and distinctly claims what are regarded as embodiments of the present disclosure and concludes with claims, the advantages of the embodiments of the present disclosure may become more readily apparent from the following description of certain examples of the embodiments of the present disclosure when read in conjunction with the accompanying drawings. [Brief description of the drawings]

[0012] [Figure 1]FIG. 1 is a schematic diagram of an exemplary apparatus that can be utilized to carry out the cyclic plasma-enhanced deposition method of the present disclosure. [Diagram 2] FIG. 2 is a process flow diagram including an exemplary process for forming a shape-selective silicon oxide film by a PEALD process according to an embodiment of the present disclosure. [Diagram 3] FIG. 3 is an exemplary unit deposition cycle of a PEALD process for forming a shape-selective silicon oxide film according to an embodiment of the present disclosure. [Figure 4] FIG. 4 is a process flow diagram including an exemplary process for forming a shape-selective silicon oxide film by a cyclic PECVD process according to an embodiment of the present disclosure. [Diagram 5] FIG. 5 is an exemplary unit deposition cycle of a cyclical PECVD process for forming a feature-selective silicon oxide film according to an embodiment of the present disclosure. [Figure 6] FIG. 6 is another exemplary unit deposition cycle of a cyclical PECVD process for forming a shape-selective silicon oxide film according to an embodiment of the present disclosure. [Figure 7] FIG. 7 is another exemplary unit deposition cycle of a cyclical PECVD process for forming a shape-selective silicon oxide film according to an embodiment of the present disclosure. [Figure 8] 8A and 8B are an exemplary non-planar substrate before and after shape-selective silicon oxide formation according to an embodiment of the present disclosure, where a silicon oxide film is selectively formed on horizontal surfaces of the non-planar substrate relative to vertical surfaces of the non-planar substrate. [Figure 9] 9A and 9B are scanning tunneling electron microscope (STEM) images of an exemplary non-planar substrate after shape-selective formation of a silicon oxide film according to an embodiment of the present disclosure, where the silicon oxide film is selective for deposition on horizontal surfaces versus vertical surfaces. [Figure 10] FIG. 10 shows the variation of both horizontal and vertical silicon oxide film thickness with increasing number of unit deposition cycles of an exemplary shape-selective PEALD process according to an embodiment of the present disclosure. [Figure 11]FIG. 11 is a process flow diagram including an exemplary process for forming a shape-selective silicon oxide film by a PEALD process according to an embodiment of the present disclosure. [Figure 12] FIG. 12 provides data illustrating the etch thickness of an exemplary silicon oxide film versus plasma contact time. [Figure 13] FIG. 13 is an exemplary unit deposition cycle of a PEALD process for forming a shape-selective silicon oxide film according to an embodiment of the present disclosure. [Figure 14] FIG. 14 is a process flow diagram illustrating an exemplary process for forming a feature-selective silicon oxide film by a combination of cyclic plasma-enhanced deposition and selective etching according to an embodiment of the present disclosure. [Figure 15] 15A and 15B are an exemplary non-planar substrate after shape-selective deposition of a silicon oxide film by shape control of a silicon oxide composition according to an embodiment of the present disclosure, and subsequent selective removal of the silicon oxide film located on a horizontal surface relative to the silicon oxide film located on a vertical surface by contacting the silicon oxide film with an etchant. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0013] It will be appreciated that elements in the figures are illustrated for simplicity and clarity and have not necessarily been drawn to scale, for example, the dimensions of some of the elements in the figures may be exaggerated relative to other elements to help improve understanding of the illustrated embodiments of the present disclosure.

[0014] Although certain specific embodiments and examples are disclosed below, it will be understood by those skilled in the art that the invention extends beyond the specifically disclosed embodiments and / or uses of the invention, as well as obvious modifications and equivalents thereof, and therefore it is not intended that the scope of the disclosed invention should be limited by the specific disclosed embodiments described below.

[0015] As used herein, the term "shape-selective" can refer to forming a film of material on a non-planar substrate having selectivity of a non-planar first plane relative to a non-planar second plane, i.e., forming a thicker material on the first plane compared to the thickness of the material on the second plane.

[0016] Additionally, the "selectivity" of a shape-selective process can be expressed as the ratio of material formed on a first planar surface of a non-planar substrate to the combined amount of material formed on the first planar surface and the second planar surface. For example, for a horizontal surface-selective process, if the shape-selective process forms 10 nanometers of material on the horizontal surface of the non-planar substrate and 1 nanometer of material on the vertical surface of the non-planar substrate, the shape-selective process is considered to have a selectivity of 90%. As another example, for a vertical surface-selective process, if the shape-selective process forms 10 nanometers of material on the vertical surface of the non-planar substrate and 1 nanometer of material on the horizontal surface of the non-planar substrate, the shape-selective process is considered to have a selectivity of 90%.

[0017] 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 may be formed.

[0018] As used herein, the term "gas" means vapor or vaporized solid and / or liquid and can be comprised of a single gas or a mixture of gases.

[0019] As used herein, the term "reactive species" may refer to one or more species produced by plasma excitation of a gas, and may include, but is not limited to, ions, radicals, and excited species.

[0020] As used herein, the term "silicon oxide film" may refer to a film of a material that includes at least one silicon component and an oxygen component. The term "silicon oxide film" may include other components in addition to at least the silicon and oxygen components, including, but not limited to, a carbon component, a nitrogen component, and a hydrogen component. For example, silicon oxide films include silicon dioxide (SiO2), silicon suboxide (SiO x ) (where x may be less than 2), silicon oxycarbide, or doped silicon oxide.

[0021] The terms "film" and "thin film" as used herein can refer to any continuous or non-continuous structures and materials deposited by the methods disclosed herein. "Films" and "thin films" can include, for example, 2D materials, nanolaminates, nanorods, nanotubes, or nanoparticles, or planar partial or complete molecular layers, or partial or complete atomic layers, or clusters of atoms and / or molecules. "Films" and "thin films" can include materials or layers that have pinholes, but are still at least partially continuous.

[0022] As used herein, the term "cyclic plasma enhanced deposition process" refers to a vapor deposition process that includes one or more repeating unit deposition cycles, specifically multiple successive repetitions of a unit deposition cycle, where the unit deposition cycle includes the use of one or more reactive species generated from a plasma.

[0023] As used herein, "plasma enhanced atomic layer deposition" (PEALD) can refer to a vapor deposition process in which a deposition cycle, preferably multiple consecutive deposition cycles, are performed in a reaction chamber. Typically, during each unit deposition cycle, a precursor is chemisorbed to the deposition surface (e.g., a substrate surface or a previously deposited underlying surface, e.g., a material deposited using a previous PEALD cycle) to form a monolayer or submonolayer that does not readily react with another precursor (i.e., a self-limiting reaction). Reactive species generated by the plasma generated from one or more precursors can then be introduced into or generated in the reaction chamber for use in converting the chemisorbed precursors to the desired material on the deposition surface. Additionally, a purge step can be utilized during each unit deposition cycle to remove excess precursors and reactive species from the reaction chamber after conversion of the chemisorbed precursors, and / or to remove excess reactants, reactive species and / or reaction by-products from the reaction chamber.

[0024] As used herein, "cyclic plasma-enhanced chemical vapor deposition" (cyclic PECVD) can refer to a gas-phase deposition process in which a deposition cycle, preferably multiple consecutive deposition cycles, is performed in a reaction chamber. Typically, during each unit deposition cycle, one or more reactive species can be generated by a plasma through the sequential application of either RF power or two or more pulses of RF power. In contrast to PEALD processes, cyclic PECVD processes typically do not employ chemisorption of a gas-phase reactant and subsequent conversion of the chemisorbed molecular layer to a desired material. Cyclic plasma-enhanced chemical vapor deposition may also be referred to as pulsed plasma-enhanced chemical vapor deposition.

[0025] As used herein, the term "horizontal surface" can refer to a plane of a substrate that extends essentially horizontally, where essentially horizontal can include a plane of a substrate that is within about 30 degrees, or within about 15 degrees, or even within 5 degrees of the horizontal.

[0026] As used herein, the term "vertical surface" can refer to a plane of a substrate that extends essentially vertically, where essentially vertical can include a plane of a substrate that is within about 30 degrees, or within about 15 degrees, or even within 5 degrees of the vertical.

[0027] It should be noted that many example materials are provided throughout the embodiments of this disclosure, and the chemical formulas provided for each of the example materials should not be construed as limiting, nor should the non-limiting example materials provided be limited by certain example stoichiometries.

[0028] It will be understood that the terms "on" or "over" can be used herein to describe relative positional relationships. Another element or layer may be directly on the layer referred to, or another layer (intermediate layer) or element may be interposed therebetween, or a layer may be disposed on the layer referred to but not completely cover the surface of the layer referred to. Thus, unless the term "directly" is used separately, the terms "on" or "over" will be interpreted as relative concepts. Similarly, the terms "under", "underlying", or "below" will be interpreted as relative concepts.

[0029] An embodiment of the present disclosure can include a method for forming a shape-selective silicon oxide film by a cyclic plasma-enhanced deposition process. Specifically, the shape-selective deposition method disclosed herein can selectively form a silicon oxide film on a first planar surface of a non-planar substrate relative to a second planar surface of the non-planar substrate. For example, a silicon oxide film can be selectively formed on a horizontal surface of the substrate relative to a vertical surface of the substrate ("horizontal surface selective process"). Alternatively, a silicon oxide film can be selectively formed on a vertical surface of the substrate relative to a horizontal surface of the substrate ("vertical surface selective process").

[0030] Embodiments of the present disclosure can provide a shape-selective formation process for forming silicon oxide films on horizontal surfaces relative to vertical surfaces by a direct shape-selective deposition process. Additionally, embodiments of the present disclosure can provide a shape-selective formation process for forming silicon oxide films on vertical surfaces relative to horizontal surfaces by deposition of silicon oxide films with shape control of silicon oxide film properties, where the deposited silicon oxide film can be contacted with an etchant that can selectively remove silicon oxide films disposed on the horizontal surfaces of a non-planar substrate.

[0031] Next generation semiconductor device processes may desire non-conformal, shape-selective deposition of silicon oxide films. For example, silicon oxide films selectively formed on horizontal surfaces of a substrate, such as horizontal surfaces of a trench structure, can be utilized as sacrificial etch masks due to the etch resistance of the selective silicon oxide films to, for example, plasma etching.

[0032] Non-conformal shape-selective film deposition has been demonstrated by a number of methods. For example, a combination of conformal silicon oxide deposition and wet chemical etching has been investigated, where the deposition of the silicon oxide film is adjusted to obtain a low quality film on the vertical surfaces of the substrate, for example on the sidewalls of a trench structure. In such an embodiment, the vertical silicon oxide film can be selectively removed by an etchant due to the significantly higher etching rate of the silicon oxide film on the vertical surfaces of the non-planar substrate compared to the silicon oxide film on the horizontal surfaces of the non-planar substrate.

[0033] Additionally, non-conformal shape-selective film deposition is possible with the use of either growth inhibitors or growth promoters. However, the use of growth inhibitors / promoters reduces the throughput of processed substrates as a result of the additional chemical wet etching steps required to obtain the desired selectivity. Furthermore, processing costs can increase due to the cost of the inhibitor / promoters chemistry and the expense of the optimization period required to reach activation / inhibition of the targeted planar surface.

[0034] The shape-selective formation process of the present disclosure may be carried out in a reaction chamber associated with a PEALD or PECVD apparatus configured with appropriate hardware for pulsing RF power and continuously supplying two or more precursors to the reaction chamber. In some embodiments of the present disclosure, the reaction chamber utilized for the formation of the shape-selective silicon oxide film may provide an anisotropic plasma, i.e., a plasma in which at least ionized species are accelerated in a substantially uniform direction, as opposed to an isotropic plasma in which excited species move in random directions. In some embodiments, the reaction chamber utilized for the formation of the shape-selective silicon oxide film may generate a plasma, for example, a capacitively coupled plasma (CCP) excited by applying RF power to one of two electrodes. Furthermore, in some embodiments, an inductively coupled plasma (ICP), an electron cyclotron resonance (ECR) plasma, a microwave surface plasma, a helicon wave plasma, or the like may be used as the plasma, and a bias voltage may be applied between the electrodes as needed to increase the DC bias between the plasma and the electrodes.

[0035] As a non-limiting example, applying a voltage between two electrodes where a non-planar substrate is placed parallel to the two electrodes allows for the formation of shape-selective silicon oxide films by tailoring the bombardment of the plasma-excited gas. A plasma is a partially ionized gas with a high free electron content (approximately 50%), and when a plasma is excited by applying an AC voltage between the parallel electrodes, the ions are induced by a self-DC bias (V DC) The accelerated ions irradiate the non-planar substrate placed on the lower electrode in a direction substantially perpendicular to the horizontal plane of the substrate, i.e., perpendicular to the horizontal plane of the lower electrode (direction of ion incidence). The impact of the plasma can be expressed by the plasma density or the kinetic energy of the ions. The plasma density can be adjusted mainly by adjusting the pressure and RF power in the reaction chamber (lower pressure and higher RF power result in higher plasma density). The plasma density can also be adjusted by applying a DC bias voltage or an AC voltage at a low frequency (e.g., less than 1 MHz) that the ions are set to follow.

[0036] The cyclic plasma enhanced deposition process of the present disclosure can form shape-selective silicon oxide films by one or more repetitions of a unit deposition cycle, which can include the generation of reactive species from a plasma. As a non-limiting example, the deposition cycle can be performed using a suitable apparatus, such as the apparatus 100 illustrated in FIG. 1. For example, FIG. 1 is a schematic diagram of an exemplary PEALD apparatus 100 usable in some embodiments of the present invention, desirably integrated with a control device programmed to perform the sequence described below. In this figure, a pair of conductive flat electrodes 104, 102 are provided in parallel and facing each other in the interior 111 (reaction region) of a reaction chamber 103, and a plasma is excited between the electrodes by applying RF power (e.g., 13.56 MHz or 27 MHz) 120 to one side and electrically grounding the other side 112. A temperature regulator is provided on the lower stage 102 (lower electrode), and the temperature of a substrate 101 placed thereon is kept constant at a predetermined temperature. The upper electrode 104 also functions as a showerhead plate, and reactant gases (and noble gases) and precursor gases are introduced into the reaction chamber 103 through gas lines 121 and 122, respectively, and through the showerhead plate 104.

[0037] Further, in the reaction chamber 103, a circular duct 113 having an exhaust line 107 is provided, through which the gas in the inside 111 of the reaction chamber 103 is exhausted. Further, a dilution gas is introduced into the reaction chamber 103 through a gas line 123. Further, in the transfer chamber 105 disposed below the reaction chamber 103, a seal gas line 124 is provided for introducing a seal gas into the inside 111 of the reaction chamber 103 via the inside 116 (transfer zone) of the transfer chamber 105, and a separation plate 114 is provided for separating the reaction zone from the transfer zone (the gate valve through which the wafer is transferred into and out of the transfer chamber 105 is omitted from this figure). The transfer chamber also includes an exhaust line 106. In some embodiments, the deposition and surface treatment of the multi-element film are performed in the same reaction space, so that all steps can be performed consecutively without exposing the substrate to air or other oxygen-containing atmosphere. In some embodiments, a remote plasma device can be used to excite the gas.

[0038] In some embodiments of the present disclosure, cyclic plasma-enhanced deposition processes can be utilized to form shape-selective silicon oxide films, such processes can include plasma-enhanced atomic layer deposition (PEALD) or cyclic plasma-enhanced chemical vapor deposition (cyclic PECVD). Briefly, a non-planar substrate or workpiece is placed in a reaction chamber, heated to a deposition temperature, and subjected to one or more repetitions of alternating surface reactions, i.e., unit deposition cycles. In some embodiments, each unit deposition cycle (i.e., PEALD cycles or cyclic PECVD cycles) includes at least two distinct phases.

[0039] In a first phase, a gas-phase reactant or a plasma generated from the gas-phase reactant can be provided into the reaction chamber and contacted with the non-planar substrate surface. This reactant or plasma-generated reactant can also be referred to herein as a "silicon precursor," "silicon-containing precursor," "silicon reactant," or "silicon reactant," and can include, for example, a gas-phase reactant or a plasma generated from a gas-phase reactant that includes a silicon component, a carbon component, and a hydrogen component.

[0040] In some embodiments of the present disclosure, the silicon reactant consists essentially of a silicon component, a carbon component, and a hydrogen component. In some embodiments, the silicon reactant can include an alkylsilane, such as dimethylsilane, trimethylsilane, tetramethylsilane, diethylsilane, triethylsilane, tetraethylsilane, t-butylsilane (and derivatives thereof), or a silicon reactant containing two silicon atoms, such as hexamethyldisilane. In some embodiments, the silicon reactant can include an arylsilane, such as phenylsilane, diphenylsilane, triphenylsilane, tetraphenylsilane, dibenzylsilane, tribenzylsilane, or tetrabenzylsilane. In some embodiments, the silicon reactant can include an aralkylsilane, such as trimethyl-(3-methylphenyl)silane, or dimethyl(4-methylphenyl)silane.

[0041] In some embodiments of the present disclosure, the silicon reactant can further include at least one of a nitrogen component or an oxygen component. For example, the silicon reactant can include at least one of an alkylalkoxysilane or an alkylaminosilane. In some embodiments, the silicon reactant can include an alkylalkoxysilane, such as methyltrimethoxysilane, ethoxy(trimethyl)silane, diethyl-methyl-ethoxysilane, ethyl(dimethyl)-ethoxysilane, tert-butyl-triethoxysilane, or butyl(trimethoxy)silane. In some embodiments, the silicon reactant can include an alkylaminosilane, such as tris(dimethylamino)ethylsilane.

[0042] In some embodiments, the silicon reactant has the following formula (I):

[0043] [ka]

[0044] (wherein R1, R2, R3, and R4 can include silicon, carbon, and hydrogen, and at least one of R1, R2, R3, and R4 is not hydrogen or silicon, and R1, R2, R3, and R4 do not include oxygen, nitrogen, or halogen).

[0045] In some embodiments, the silicon reactant has the following formula (II-IV):

[0046] [ka]

[0047] (wherein R1, R2, R3, and R4 can include silicon, carbon, and hydrogen, and at least R3 can be neither hydrogen nor silicon, and R1, R2, R3, and R4 do not include oxygen, nitrogen, or halogen).

[0048] In some embodiments, the silicon reactant has the following formula (V-VII):

[0049] [ka]

[0050] (wherein R1, R2, R3, and R4 can include silicon, carbon, and hydrogen, and at least R3 can be neither hydrogen nor silicon, and R1, R2, R3, and R4 do not include oxygen, nitrogen, or halogen).

[0051] In a second phase, a second reactant including a reactive species is provided to convert the silicon reactant into a silicon oxide film, in some embodiments of the present disclosure, the second reactant can include a reactive species generated from a plasma generated from a gas including an oxygen precursor and a noble gas.

[0052] In some embodiments, the oxygen precursor can include at least one of molecular oxygen (O2), carbon dioxide (CO2), or nitrous oxide (NO). In some embodiments, the noble gas can include at least one of argon, nitrogen, or helium. In some embodiments, the flow ratio of the noble gas to the oxygen precursor can be greater than 1, or greater than 2, or even greater than 3.

[0053] A plasma generated from a gas consisting of only an oxygen precursor is generally isotropic and mainly contains oxygen radicals that are not affected by the electric field and traverse in a substantially random direction. An embodiment of the present disclosure generates a plasma from a gas including an oxygen precursor and a noble gas, so that the generated plasma may be rich in ions that may be affected by the electric field, in particular, ions are anisotropically accelerated downward toward the non-planar substrate in a substantially vertical direction and irradiate or impinge on the non-planar substrate in a direction substantially perpendicular to the horizontal plane of the substrate, i.e., perpendicular to the horizontal plane of the lower electrode of the deposition apparatus. For example, the ion incidence direction may be substantially perpendicular to the lower electrode 102 of the apparatus 100 of FIG. 1. In such an embodiment of the present disclosure, the ion impact rate, i.e., the rate at which ions impact the non-planar substrate, is greater on the horizontal surface of the non-planar substrate compared to the vertical surface of the non-planar substrate, resulting in shape-selective deposition of silicon oxide films on the horizontal surface of the substrate compared to the vertical surface of the substrate. Furthermore, differences in ion bombardment rates affecting horizontal and vertical surfaces can provide shape control of the composition of the silicon oxide film, i.e., the composition of the silicon oxide film on horizontal surfaces can be different than the composition of the silicon oxide film on vertical surfaces, which can enable vertical surface selective silicon oxide films by selective etching of silicon oxide films disposed on horizontal surfaces of a non-planar substrate.

[0054] Horizontal surface selective silicon oxide formation process In some embodiments of the present disclosure, a method of forming a shape-selective silicon oxide film by a cyclic plasma-enhanced deposition process can include selectively forming a silicon oxide film on a horizontal surface of a non-planar substrate relative to a vertical surface of the non-planar substrate, i.e., a greater thickness of silicon oxide material can be formed on the horizontal surface of the non-planar substrate compared to the thickness of silicon oxide material that can be formed on the vertical surface of the non-planar substrate.

[0055] In some embodiments of the present disclosure, the horizontal surface selective silicon oxide formation process can be achieved by directly depositing a silicon oxide film on a horizontal surface selectively relative to a vertical surface. In some embodiments, the horizontal surface selective silicon oxide deposition process of the present disclosure can include a cyclic plasma enhanced deposition process, such as a plasma enhanced atomic layer deposition (PEALD) process or a cyclic plasma enhanced chemical vapor deposition (cyclic PECVD) process.

[0056] Accordingly, embodiments of the present disclosure can include a method for forming a shape-selective silicon oxide film by a cyclic plasma-enhanced deposition process, the method including providing a non-planar substrate having one or more horizontal surfaces and one or more vertical surfaces into a reaction chamber, contacting the non-planar substrate with a gas-phase reactant including a silicon component, a carbon component, and a hydrogen component, contacting the non-planar substrate with reactive species generated from a plasma generated from a gas including an oxygen precursor and a noble gas, and forming a silicon oxide film either selectively on the horizontal surfaces of the non-planar substrate or selectively on the vertical surfaces of the non-planar substrate.

[0057] Embodiments of the present disclosure also include a method of forming a shape-selective silicon oxide film on a non-planar substrate by a plasma-enhanced atomic layer deposition process, the method including contacting the non-planar substrate with a gas-phase reactant including a silicon component, a carbon component, and a hydrogen component, contacting the non-planar substrate with a plurality of ions including at least oxygen ions, where the plurality of ions impact the substrate in a direction substantially perpendicular to a horizontal surface of the non-planar substrate, and selectively depositing a silicon oxide film on the horizontal surfaces of the non-planar substrate relative to the vertical surfaces of the non-planar substrate.

[0058] A non-limiting example embodiment of a cyclic plasma enhanced deposition process that can be utilized to form laterally selective silicon oxide films is Plasma Enhanced Atomic Layer Deposition (PEALD). Briefly, a substrate or workpiece is placed in a reaction chamber and subjected to alternating surface reactions. In some embodiments, a silicon oxide film can be formed by repeating self-limiting PEALD cycles.

[0059] An exemplary PEALD process for forming a laterally selective silicon oxide film is illustrated with reference to Figure 2. The exemplary PEALD process 200 can include two phases: a first phase includes contacting a substrate with a gas-phase reactant including a silicon component, a carbon component, and a hydrogen component, and a second phase includes contacting the substrate with reactive species generated from a plasma.

[0060] More specifically, and with reference to FIG. 2, the exemplary process 200 may begin with process block 210, which includes providing a substrate into a reaction chamber and heating the substrate to a suitable deposition temperature.

[0061] In some embodiments, the substrate can include one or more materials and material surfaces, including, but not limited to, semiconductor materials, dielectric materials, and metal materials. For example, the substrate can include, but is not limited to, semiconductor materials, such as silicon (Si), germanium (Ge), germanium tin (GeSn), silicon germanium (SiGe), silicon germanium tin (SiGeSn), silicon carbide (SiC), or III-V semiconductor materials.

[0062] In some embodiments of the present disclosure, the substrate may include a patterned non-planar substrate including high aspect ratio features, such as trench structures, vertical gap features, and / or fin structures. The term "gap feature" may refer to an opening or cavity disposed between opposing sloping sidewalls or two protrusions extending vertically from the surface of the substrate, or between opposing sloping sidewalls of a depression extending vertically into the surface of the substrate, and such gap features may be referred to as "vertical gap features" including both horizontal and vertical surfaces. In some embodiments, the vertical gap feature may have an aspect ratio (height:width) greater than 2:1, or greater than 5:1, or greater than 10:1, or greater than 25:1, or greater than 50:1, or even greater than 100:1, with "greater" as used in this example referring to a greater distance in the height of the gap feature.

[0063] In some embodiments, the substrate on which deposition is desired is loaded into the reaction chamber. In some embodiments, the reaction chamber may form part of a cluster tool in which various different processes in the formation of semiconductor device structures are performed. In some embodiments, a flow type reactor may be utilized. In some embodiments, a showerhead type reactor may be utilized. In some embodiments, a space-divided reactor may be utilized. In some embodiments, a high volume manufacturing capable single wafer PEALD reactor may be utilized. In other embodiments, a batch reactor containing multiple substrates may be utilized. For embodiments in which a batch PEALD reactor is used, the number of substrates may range from 10 to 200, or from 50 to 150, or even from 100 to 130.

[0064] In some embodiments, the exposed surface of the substrate can be pretreated, if desired, to provide reactive sites for reaction with the first phase of the PEALD process. In some embodiments, a separate pretreatment step is not required. In some embodiments, the substrate is pretreated to obtain a desired surface termination, for example, by exposing the substrate surface to a pretreatment plasma.

[0065] In some embodiments of the present disclosure, a substrate disposed within the reaction chamber may be heated to a desired deposition temperature for the subsequent cyclical deposition stage 205 of the exemplary PEALD process 200 (FIG. 2). For example, the substrate may be heated to a substrate deposition temperature of less than about 600° C., or less than about 550° C., or less than about 500° C., or less than about 450° C., or less than about 400° C., or less than about 350° C., or less than about 300° C., or even less than about 250° C. In some embodiments of the present disclosure, the substrate deposition temperature during the exemplary plasma enhanced atomic layer deposition process 200 may be between about 150° C. and about 600° C.

[0066] In addition to controlling the temperature of the substrate, the pressure in the reaction chamber can also be adjusted to enable deposition of a desired silicon oxide film. In some embodiments, by adjusting the pressure in the reaction chamber, the occupancy density and the nature of the reactive species generated in the plasma can also be controlled. Thus, in some embodiments, the pressure in the reaction chamber during the exemplary PEALD process 200 can be adjusted to a pressure greater than 150 Pascals, or greater than 300 Pascals, or greater than 450 Pascals, or greater than 600 Pascals, or even greater than 800 Pascals. For example, in some embodiments, the pressure in the reaction chamber during the exemplary PEALD process 200 can be adjusted between 150 Pascals and 800 Pascals.

[0067] Once the temperature of the substrate is set to the desired deposition temperature, the pressure in the reaction chamber may be adjusted as necessary, and the exemplary process 200 may continue with a cyclic deposition stage 205, which may include supplying one or more deposition gases to the reaction chamber, where the deposition gases may include gas-phase reactants, purge gases, carrier gases, and gases utilized to generate reactive species from the plasma.

[0068] Briefly, in the first phase of the cyclical deposition stage 205, the gas phase reactants include a silicon component, a carbon component, and a hydrogen component, and a "silicon precursor" may be "pulsed" into the reaction chamber, where the term "pulse" can be understood to include supplying a reactant into the reaction chamber for a predetermined period of time. The term "pulse" does not limit the length or duration of the pulse, but the pulse can be of any length of time. In some embodiments, in addition to the silicon precursor, a gas mixture can be continuously supplied to the reaction chamber during the cyclical deposition stage 205 of the exemplary PEALD process 100. In some embodiments, the gas mixture can include both a gas mixture for the generation of the reactants utilized during the second stage of the PEALD process 200 and can also be utilized as a purge gas to remove excess reactants, reactants, and reaction by-products from the reaction chamber.

[0069] More specifically, the cyclical deposition stage 205 of the exemplary PEALD process 200 can continue with process block 220, which includes contacting the substrate with a gas-phase reactant, i.e., a silicon precursor, that includes silicon, carbon, and hydrogen components.

[0070] In some embodiments, a silicon precursor may be initially delivered to the substrate. After an initial surface termination, if necessary or desired, a silicon precursor pulse may be delivered to the substrate. According to some embodiments, the silicon precursor may be delivered to the reaction chamber with a carrier gas flow. In some embodiments, the silicon precursor may include a volatile silicon species that reacts with the surface of the substrate. The silicon precursor pulse may self-saturate the substrate surface so that excess components of the silicon precursor pulse do not further react with the molecular layer formed by the process.

[0071] The silicon precursor pulses are preferably delivered as gas phase reactants. A silicon precursor gas may be considered "volatile" for purposes of this disclosure if the species exhibits sufficient vapor pressure under process conditions to transport the species to the substrate surface in sufficient concentration to saturate the exposed surface.

[0072] In some embodiments of the present disclosure, the gas phase reactant consists essentially of a silicon component, a carbon component, and a hydrogen component, hi some embodiments, the gas phase reactant may include an alkylsilane, an arylsilane, an aralkylsilane, an alkylalkoxysilane, or an alkylaminosilane, as previously described herein.

[0073] In some embodiments of the present disclosure, the silicon precursor may be pulsed into the reaction chamber for about 0.05 seconds to about 5.0 seconds, or about 0.1 seconds to about 3 seconds, or even about 0.2 seconds to about 1.0 seconds. In some embodiments, the silicon precursor may be pulsed into the reaction chamber for less than 0.1 seconds, or even less than 0.05 seconds. Furthermore, during contact of the substrate with the silicon precursor, the flow rate of the silicon precursor may be less than 1000 sccm, or less than 500 sccm, or less than 100 sccm, or less than 50 sccm, or even less than 5 sccm. Furthermore, during contact of the substrate with the silicon precursor, the flow rate of the silicon precursor may range from about 5 to 50 sccm, or from about 50 to 100 sccm, or from about 100 to about 1000 sccm.

[0074] After a sufficient time for the molecular layer to adsorb onto the substrate surface, the excess silicon precursor may be removed from the reaction chamber. In some embodiments, the excess silicon precursor may be purged by stopping the flow of the gas phase silicon precursor while continuing to flow the carrier gas, purge gas, or gas mixture for a sufficient time to diffuse or purge excess reactants and reactant by-products, if any, from the reaction chamber. In some embodiments, the excess silicon precursor may be purged using one or more inert gases, such as nitrogen, helium, or argon, which may be flowed throughout the entire cyclic deposition phase 205 of the exemplary PEALD process 200.

[0075] In some embodiments, the silicon precursor may be purged from the reaction chamber for about 0.1 seconds to about 60 seconds, or about 0.3 seconds to about 30 seconds, or even about 0.3 seconds to about 10 seconds. The delivery and removal of the silicon precursor can be considered the first or "silicon phase" of the exemplary PEALD process 200.

[0076] Once purging of the reaction chamber of excess silicon precursor and any reaction by-products is complete, the cyclical deposition stage 205 of the exemplary PEALD process 200 can continue with a second phase by process block 230, which includes contacting the substrate with reactive species generated from a plasma generated from a gas including an oxygen precursor and a noble gas.

[0077] In some embodiments, the oxygen precursor can include at least one of molecular oxygen (O2), carbon dioxide (CO2), or nitrous oxide (NO). In some embodiments, the noble gas can include at least one of argon, nitrogen, or helium. In some embodiments, the flow ratio of the noble gas to the oxygen precursor into the reaction chamber can be greater than 1, or greater than 2, or even greater than 3. As noted above, the plasma ("oxygen-based plasma") can be enriched with ions, including at least oxygen ions, and can be generated using a parallel plate electrode configuration that can anisotropically accelerate a plurality of ions substantially vertically downward toward the substrate.

[0078] In some embodiments, the oxygen-based plasma can be generated by applying RF power of about 50 W to about 1000 W, or about 100 W to about 500 W, or about 100 W to about 300 W. In some embodiments, the plasma may be generated in situ, while in other embodiments, the plasma may be generated remotely. In some embodiments, a showerhead reactor is utilized, and the plasma is generated between a lower electrode (i.e., a susceptor on which the substrate is disposed) and an upper electrode (i.e., a showerhead plate).

[0079] In some embodiments, reactive species generated from the plasma can contact the substrate for between about 0.1 seconds and about 12 seconds, or between 0.5 seconds and about 5.0 seconds, or even between 0.5 seconds and about 2.0 seconds. In some embodiments, reactive species generated from the plasma may contact the substrate for less than 1 second, or less than 0.5 seconds, or even less than 0.1 seconds.

[0080] After a period of time sufficient to completely saturate and react with the oxygen-based plasma pulse the previously adsorbed molecular layer, all excess reactants and reaction by-products can be removed from the reaction chamber. Similar to the removal of the gas phase reactants, i.e., silicon precursor, this step can include stopping the generation of reactive species and continuing to flow the inert gas. The inert gas flow can flow for a period of time sufficient to allow the excess reactants and volatile reaction by-products to diffuse and be purged from the reaction chamber. For example, the purge process can be utilized for about 0.1 seconds to about 10 seconds, or about 0.1 seconds to about 4.0 seconds, or even about 0.1 seconds to about 0.5 seconds. Together, the supply and removal of the oxygen-based plasma represent a second, reactive species phase in the exemplary silicon nitride PEALD process 200 of FIG. 2.

[0081] The method in which the substrate is contacted with alternating sequential gas phase silicon precursors and reactive species generated from a gas including an oxygen precursor and a noble gas may constitute a unit deposition cycle. In some embodiments of the present disclosure, the exemplary PEALD process 200 may include repeating the unit deposition cycle one or more times. For example, the cyclical deposition stage 205 of the exemplary PEALD process 200 may continue with a decision gate 240 that determines whether the PEALD process 200 continues or ends. The decision gate 240 of the process block is determined based on the thickness of the deposited silicon oxide film, for example, if the thickness of the silicon oxide film is insufficient for the desired device structure, the PEALD process 200 may return to process block 220 and the process of contacting the substrate with a silicon precursor (process block 220) and contacting the substrate with reactive species (process block 230) may be repeated one or more times. Once the silicon oxide film is deposited to a desired thickness, the exemplary PEALD process 200 may end by process block 250, and the silicon oxide film may undergo additional processes to form a semiconductor device structure.

[0082] Although a PEALD cycle is generally referred to herein as beginning with a silicon phase, it is contemplated that in other embodiments, the cycle may begin with a reactive species phase. One skilled in the art will recognize that the first precursor phase generally reacts with the terminations left by the last phase of the previous cycle. Thus, when the reactive species is the first phase of a PEALD cycle, no reactants are pre-adsorbed on the substrate surface or present in the reaction chamber, but in subsequent cycles, the reactive species phase effectively follows the silicon phase. In some embodiments, one or more distinct PEALD cycles are provided in the deposition process.

[0083] Another overview of a non-limiting exemplary unit deposition cycle of a horizontally selective PEALD process of the present disclosure is illustrated with reference to Figure 3. As illustrated in Figure 3, the horizontal axis represents time parameters but not necessarily the actual time length of the individual processes, and the vertical axis represents the on or off states of gas flow and RF power, with the higher level on the vertical axis for each parameter representing the on state but not necessarily the actual amount of the associated parameter, and the lowest level on each line of the vertical axis representing the off state, i.e., zero gas flow or no RF power being applied.

[0084] Briefly, in a first period 310 (i.e., precursor pulse period) of a unit deposition cycle, a silicon precursor may be pulsed into the reaction chamber along with a flow of a noble gas and an oxygen precursor. In this first period 310, the silicon precursor may chemisorb onto the non-planar surface of the substrate to form up to a monolayer. In a second period 320 (i.e., purge period), the flow of the silicon precursor is stopped and the flow of the noble gas and oxygen precursor continues to purge excess silicon precursor and any reaction by-products from the reaction chamber. In a third period 330 (i.e., RF pulse period), the flow of the oxygen precursor and noble gas continues into the reaction chamber and a pulse of RF power is supplied to the gas to excite a plasma and generate reactive species that react with the chemisorbed silicon precursor to thereby form a silicon oxide film. In a fourth period 340 (i.e., purge period), the RF power is off and the flow of the noble gas and oxygen precursor continues to purge excess reactive species and any reaction by-products from the reaction chamber.

[0085] Another non-limiting example embodiment of a cyclic plasma enhanced deposition process that can be utilized to form laterally selective silicon oxide films is cyclic plasma enhanced chemical vapor deposition (cyclic PECVD). Briefly, a non-planar substrate or workpiece can be placed in a reaction chamber and subjected to one or more cyclic PECVD deposition cycles.

[0086] An exemplary cyclical PECVD process for forming a laterally selective silicon oxide film is illustrated with reference to Figure 4. The exemplary cyclical PECVD process 400 can include two phases. The first phase includes contacting the substrate with a first reactant generated from a gas phase reactant including a silicon component, a carbon component, and a hydrogen component, and the second phase includes contacting the substrate with a second reactant generated from a gas including an oxygen precursor and a noble gas.

[0087] More specifically, and with reference to FIG. 4, an exemplary process 400 may begin with process block 410, which includes providing a substrate into a reaction chamber and heating the substrate to a suitable deposition temperature.

[0088] In some embodiments of the present disclosure, the substrate may include materials and shapes previously disclosed herein, particularly including non-planar substrates with one or more horizontal surfaces and one or more vertical surfaces. Additionally, the reaction chamber may include any of the reaction chambers (and related devices) previously described herein, particularly including plasma-enhanced chemical vapor deposition (PECVD) reaction chambers and related devices with parallel plate electrode configurations for generating anisotropic plasma.

[0089] In some embodiments of the present disclosure, a substrate disposed within the reaction chamber may be heated to a desired deposition temperature for the subsequent cyclical deposition stage 405 of the exemplary cyclical PECVD process 400 (FIG. 4). For example, the substrate may be heated to a substrate temperature of less than about 600° C., or less than about 550° C., or less than about 500° C., or less than about 450° C., or less than about 400° C., or less than about 350° C., or less than about 300° C., or even less than about 250° C. In some embodiments of the present disclosure, the substrate temperature during the exemplary cyclical PECVD process 300 may be between about 150° C. and about 600° C.

[0090] In addition to controlling the temperature of the substrate, the pressure in the reaction chamber can also be adjusted to enable deposition of a desired silicon oxide film. In some embodiments, by adjusting the pressure in the reaction chamber, the occupancy density and the nature of the reactive species generated in the plasma can also be controlled. Thus, in some embodiments, the pressure in the reaction chamber during the exemplary cyclical PECVD process 400 can be adjusted to a pressure of greater than 150 Pascals, or greater than 300 Pascals, or greater than 450 Pascals, or greater than 600 Pascals, or even greater than 800 Pascals. For example, in some embodiments, the pressure in the reaction chamber during the exemplary cyclical PECVD process 400 can be adjusted between 150 Pascals and 800 Pascals.

[0091] Once the temperature of the substrate is set to the desired deposition temperature and the pressure in the reaction chamber is adjusted as desired, the exemplary process 400 can continue with a cyclical deposition stage 405, which can include contacting the substrate with a first reactive species generated from the plasma and contacting the substrate with a second reactive species generated from the plasma.

[0092] More specifically, the cyclic deposition stage 405 of the exemplary cyclic PECVD process 400 can continue with process block 420 which includes contacting the substrate with a first reactant generated from a gas-phase reactant, i.e., a silicon precursor, that includes a silicon component, a carbon component, and a hydrogen component.

[0093] In some embodiments, the first reactant may include a plurality of reactants generated from a gas phase reactant including at least a silicon component, a carbon component, and a hydrogen component. For example, the gas phase reactant may include any of the silicon precursors previously disclosed herein, including, but not limited to, an alkylsilane, an arylsilane, an aralkylsilane, an alkylalkoxysilane, or an alkylaminosilane.

[0094] In some embodiments of the present disclosure, the first reactant can contact the non-planar substrate for about 0.05 seconds to about 5.0 seconds, or about 0.1 seconds to about 3 seconds, or even about 0.2 seconds to about 1.0 seconds. Further, during contact of the substrate with the first reactant, the flow rate of the gas phase reactant can be less than 1000 sccm, or less than 500 sccm, or less than 100 sccm, or less than 50 sccm, or even less than 5 sccm.

[0095] The cyclic deposition stage 405 of the exemplary cyclic PECVD process 400 can continue with process block 430, which includes contacting the substrate with a second reactant generated from a gas comprising an oxygen precursor and a noble gas. In some embodiments, the oxygen precursor can include at least one of molecular oxygen (O), carbon dioxide (CO), or nitrous oxide (NO), and the noble gas can include at least one of argon, nitrogen, or helium.

[0096] In some embodiments, the second reactive species can be generated from the plasma and can contact the substrate for between about 0.1 seconds and about 12 seconds, or between 0.5 seconds and about 5.0 seconds, or even between 0.5 seconds and about 2.0 seconds. In some embodiments, the second reactive species generated from the plasma can contact the substrate for less than 1 second, less than 0.5 seconds, or even less than 0.1 seconds.

[0097] The manner in which the substrate is contacted with the first reactive species and the second reactive species may constitute a unit deposition cycle. In some embodiments of the present disclosure, the exemplary cyclical PECVD process 400 may include repeating the unit deposition cycle one or more times. For example, the cyclical deposition stage 405 of the exemplary cyclical PECVD process 400 may continue with a decision gate 440 that determines whether the cyclical PECVD process 400 continues or ends. The decision gate 440 of the process block is determined based on the thickness of the deposited silicon oxide film, for example, if the thickness of the silicon oxide film is insufficient for the desired device structure, the cyclical PECVD process 400 may return to process block 420 and the process of contacting the substrate with the first reactive species (process block 420) and contacting the substrate with the second reactive species (process block 430) may be repeated one or more times. Once the silicon oxide film is deposited to a desired thickness, the exemplary cyclical PECVD process 400 may end by process block 450, and the silicon oxide film may undergo additional processes to form a semiconductor device structure.

[0098] Although the exemplary cyclical PECVD process 400 of FIG. 4 is illustrated as first contacting the substrate with a first reactive species and then contacting the substrate with a second reactive species, it should be understood that any alternating sequence of contacting the substrate with reactive species can be utilized in the cyclical PECVD process of the present disclosure. For example, in some embodiments, both the first reactive species and the second reactive species may contact the substrate simultaneously within a unit deposition cycle. As another example, in some embodiments, the second reactive species may contact the substrate and then subsequently contact the substrate with the first reactive species within a unit deposition cycle. In some embodiments, the substrate may be repeatedly contacted with the first reactive species and then subsequently contact the substrate with the second reactive species one or more times within a unit deposition cycle. Alternatively, the substrate may be repeatedly contacted with the second reactive species and then subsequently contact the substrate with the first reactive species one or more times within a unit deposition cycle. In some embodiments, a purge cycle may be after contacting the substrate with reactive species as previously described herein.

[0099] Another overview of a non-limiting exemplary unit deposition cycle of the laterally selective cyclical PECVD process of the present disclosure is illustrated with reference to Figure 5. As illustrated in Figure 5, and as described with reference to Figure 3, the horizontal axis represents the time parameter and the vertical axis represents the on or off state.

[0100] Briefly, in a first period 510 of a unit deposition cycle (i.e., the deposition period), a noble gas and oxygen precursor can be flowed into the reaction chamber along with a pulse of silicon precursor while RF power is continuously supplied. In the second 520, third 530, and fourth 540 periods (i.e., the purge periods), the flow of silicon precursor can be turned off while the flow of noble gas and oxygen precursor is maintained along with the continuous supply of RF power.

[0101] Thus, in some embodiments, a unit deposition cycle includes simultaneously contacting the substrate with the first and second reactants and purging excess first and second reactants and any reaction by-products. In such embodiments, the first and second reactants may contact the non-planar substrate for less than 1 second, or less than 0.5 seconds, or less than 0.1 seconds. In some embodiments, the brief contact of the non-planar substrate with the first and second reactants may result in shape-selective deposition of a silicon oxide film on the top horizontal surfaces of the non-planar substrate, e.g., more material is deposited on the top horizontal surfaces of the trench structure compared to the lower horizontal surfaces, i.e., the bottom surface of the trench structure, and the vertical surfaces, i.e., the sidewalls of the trench.

[0102] Another exemplary unit deposition cycle of an exemplary laterally selective cyclical PECVD process of the present disclosure is illustrated with reference to Figure 6. As illustrated in Figure 6, and as described with reference to Figure 3, the horizontal axis represents the time parameter and the vertical axis represents the on or off state.

[0103] Briefly, in the first period 610 of the unit deposition cycle (i.e., the deposition period), the noble gas can flow into the reaction chamber along with a pulse of the oxygen precursor. Additionally, in the first period 610, the silicon precursor can be introduced into the reaction chamber by two or more discontinuous pulses, and the RF power can be applied as discontinuous pulses. In the second period 620 of the unit deposition cycle (i.e., the purge period), the oxygen precursor flow, the silicon precursor flow, and the RF power can be off while the flow of the noble gas is maintained in the reaction chamber, thereby purging the reaction chamber. In the third period 630 of the unit deposition cycle (i.e., the treatment period), the flow of the noble gas is increased, i.e., increased for a selected time, and discontinuous pulses of RF power can be applied to the noble gas, thereby generating excited species of the noble gas. In some embodiments, the excited species of the noble gas, e.g., argon ions or helium ions, can be used to remove excess silicon oxide film deposits located on the edges of horizontal surfaces of the non-planar substrate. In a fourth period 640 (ie, the purge period), the flow of the noble gas can be reduced to previous flow levels while the oxygen precursor flow, silicon precursor flow, and RF power are turned off.

[0104] Thus, in some embodiments, a unit deposition cycle can include simultaneously contacting a substrate with a first reactant and a second reactant, purging excess first reactant and excess second reactant and any reaction by-products, contacting the substrate with a third reactant generated from a noble gas, i.e., plasma excitation of the noble gas, and purging excess third reactant and any reaction by-products from the reaction chamber. In such embodiments, silicon oxide films can be selectively deposited on horizontal surfaces of a non-planar substrate relative to vertical surfaces of the non-planar substrate.

[0105] Another exemplary unit deposition cycle of an exemplary laterally selective cyclical PECVD process of the present disclosure is illustrated with reference to Figure 7. As illustrated in Figure 7, and as described with reference to Figure 3, the horizontal axis represents the time parameter and the vertical axis represents the on or off state.

[0106] Briefly, in a first period 710 (i.e., deposition period) of a unit deposition cycle, a noble gas can be flowed into the reaction chamber along with two or more pulses of a silicon precursor. Additionally, during the first period 710, discontinuous pulses of RF power can be applied to the gas. In such an embodiment, a film comprising silicon, carbon, and hydrogen can be deposited by a sputtering effect on a horizontal surface of a substrate. In a second period 720 (i.e., purge period), the noble gas flow can be maintained and the silicon precursor flow and RF power can be turned off. In a third period 730 (i.e., oxidation period), the noble gas flow can be maintained while an oxygen precursor pulse is provided into the reaction chamber along with discontinuous pulses of RF power. In some embodiments, the third period 730 can generate an oxygen-based plasma that can oxidize a previously sputter-deposited film, thereby forming a silicon oxide film. In a fourth period 740 (i.e., purge period), the noble gas flow can be maintained while the oxygen precursor flow, silicon precursor flow, and RF power are turned off.

[0107] Thus, in some embodiments, a unit deposition cycle can include contacting the substrate with a first reactive species, contacting the substrate with a fourth reactive species generated from a gas that includes a noble gas, purging all reactive species and reaction by-products from the reaction chamber, contacting the substrate with a second reactive species, and purging all reactive species and reaction by-products from the reaction chamber. In such embodiments, a silicon oxide film can be selectively deposited on horizontal surfaces of a non-planar substrate relative to vertical surfaces of the non-planar substrate.

[0108] As a non-limiting example of an embodiment of the present disclosure, FIGS. 8A-B illustrate schematic cross-sectional views of an exemplary non-planar substrate before (FIG. 8A) and after (FIG. 8B) shape-selective silicon oxide formation, where a silicon oxide film is selectively formed on horizontal surfaces of the non-planar substrate relative to vertical surfaces of the non-planar substrate.

[0109] More specifically, Figure 8A illustrates a schematic cross-sectional view of a non-planar substrate 800. The non-planar substrate can include all of the materials and shapes described hereinabove, and in certain embodiments, the non-planar substrate 800 can include a silicon substrate. The non-planar substrate 800 can include a number of trench structures 802 ("vertical gap features") that can include one or more horizontal surfaces 804 and one or more vertical surfaces 806.

[0110] 8B illustrates a schematic cross-sectional view of the non-planar substrate 800 after forming shape-selective silicon oxide on the horizontal and vertical surfaces. As illustrated in FIG. 8B, a silicon oxide film 808 may be deposited on the non-planar substrate 800 utilizing either the PEALD process or the cyclical PECVD process described above. In this particular example, the silicon oxide is formed by a horizontal surface-selective process, and thus the silicon oxide film 808 may comprise a silicon oxide film 810 disposed on the horizontal surfaces of the non-planar substrate 800 having a greater thickness than a silicon oxide film 812 disposed on the vertical surfaces of the non-planar substrate 800.

[0111] As previously disclosed herein, the "selectivity" of a shape-selective process can be expressed as the percentage of material formed on a first planar surface of a non-planar substrate relative to the total amount of material formed on the first and second planar surfaces. In this example of a horizontally selective process, the selectivity can be calculated as a percentage ratio of the thickness of the silicon oxide film disposed on the horizontal surface compared to the sum of the thicknesses of the silicon oxide film disposed on both the horizontal and vertical surfaces. Thus, in some embodiments of the present disclosure, the shape selectivity may be greater than 50%, or greater than 60%, or greater than 70%, or greater than 80%, or greater than 90%, or even equal to 100%, for deposition on a horizontal surface of a non-planar substrate compared to deposition on a vertical surface of the non-planar substrate.

[0112] As another non-limiting example of an embodiment of the present disclosure, FIGS. 9A-B illustrate scanning tunneling electron microscope (STEM) images of an exemplary non-planar substrate after shape-selective formation of a silicon oxide film, where the silicon oxide film is selective for deposition on horizontal surfaces versus vertical surfaces.

[0113] More specifically, the nonplanar shape-selective silicon oxide films of FIGS. 9A-B were deposited by a PEALD process utilizing hexamethyldisilane as the silicon precursor, molecular oxygen (O) as the oxygen precursor, and argon as the noble gas at a deposition temperature of about 250° C.

[0114] Figure 9A illustrates a non-planar silicon substrate 900, a silicon oxide film 902 disposed on a horizontal surface of the non-planar substrate, and a silicon oxide film 904 disposed on a vertical surface of the non-planar substrate. In this non-limiting example, a unit deposition cycle of the PEALD process was repeated 500 times to obtain the silicon oxide film thickness illustrated in Figure 9A. Inspection of Figure 9A illustrates that the silicon oxide film 902 disposed on the horizontal surface has a thickness of about 7 nanometers, and the silicon oxide film 904 disposed on the vertical surface has a thickness of about 3 nanometers, resulting in a horizontal surface selective process with a selectivity of 70%.

[0115] Figure 9B illustrates another non-planar silicon substrate 906, a silicon oxide film 908 disposed on a horizontal surface of the non-planar substrate, and a silicon oxide film 910 disposed on a vertical surface of the non-planar substrate. In this non-limiting example, a unit deposition cycle of the PEALD process was repeated 1000 times to obtain the silicon oxide film thickness illustrated in Figure 9B. Inspection of Figure 9B illustrates that the silicon oxide film 908 disposed on the horizontal surface has a thickness of about 11 nanometers, and the silicon oxide film 910 disposed on the vertical surface has a thickness of about 3.5 nanometers, resulting in a horizontal surface selective process with a selectivity of 75%.

[0116] As another non-limiting example of an embodiment of the present invention, FIG. 10 illustrates the change in both horizontal and vertical silicon oxide film thickness with increasing number of unit deposition cycles of an exemplary shape-selective PEALD. More specifically, the shape-selective PEALD process of this example is a horizontal surface selective process, i.e., a thicker silicon oxide film is deposited on the horizontal surface compared to the thickness of the silicon oxide film deposited on the vertical surface. In this exemplary PEALD process, the silicon precursor is hexamethyldisilane, the oxygen precursor is molecular oxygen (O2), and the noble gas is argon, and the deposition temperature is about 250° C. Another inspection of FIG. 10 illustrates that the silicon oxide film disposed on the horizontal surface is significantly thicker than the silicon oxide film disposed on the vertical surface. For example, the silicon oxide film deposited after 500 deposition cycles has a thickness of about 7 nanometers in the horizontal direction and about 3 nanometers in the vertical direction, resulting in a selectivity of 70%. As another example, a silicon oxide film deposited after 1000 deposition cycles has a thickness of about 11 nanometers in the horizontal direction and 3.5 nanometers in the vertical direction, resulting in a selectivity of 75%.

[0117] Vertical surface selective silicon oxide formation process In some embodiments of the present disclosure, a method of forming a shape-selective silicon oxide film by a cyclic plasma-enhanced deposition process can include selectively forming a silicon oxide film on a vertical surface of a non-planar substrate relative to a horizontal surface of the non-planar substrate, i.e., a greater thickness of silicon oxide material can be formed on the vertical surface of the non-planar substrate compared to the thickness of silicon oxide material that can be formed on the horizontal surface of the non-planar substrate.

[0118] In some embodiments of the present disclosure, a vertically selective silicon oxide formation process can be achieved utilizing the feature-selective deposition methods previously disclosed, along with selective etching of silicon oxide films disposed on horizontal surfaces.

[0119] In some embodiments, the vertical surface selective process can be achieved by forming a feature selective silicon oxide film by cyclic plasma enhanced deposition, such as plasma enhanced atomic layer deposition (PEALD) or cyclic plasma enhanced chemical vapor deposition (cyclic PECVD). In some embodiments, the cyclic plasma enhanced deposition can include cyclic etching of a silicon oxide film disposed on a horizontal surface of a non-planar substrate. In some embodiments, the silicon oxide film can be contacted with an etchant after deposition.

[0120] In some embodiments, selectively forming a silicon oxide film on the vertical surfaces of the non-planar substrate includes depositing a silicon oxide film having a higher carbon content on the vertical surfaces of the non-planar substrate compared to the carbon content of the silicon oxide film on the horizontal surfaces of the non-planar substrate, i.e., morphological and compositional control of the silicon oxide film deposition. In addition to utilizing an anisotropic oxygen-based plasma generated from a gas that includes an oxygen precursor and a noble gas, a silicon precursor that includes a silicon component, a carbon component, and a hydrogen component can be utilized to enable morphological and compositional control of the silicon oxide film deposition.

[0121] As a non-limiting example of the morphological composition control of silicon oxide film deposition, a unit deposition cycle of the cyclic plasma enhanced deposition process can include chemisorbing a silicon precursor onto a non-planar surface, forming up to a monolayer of the silicon precursor, and then contacting the non-planar substrate with an anisotropic plasma containing a plurality of ions accelerated downward toward the substrate in a substantially vertical direction. Because the ion incidence direction is substantially perpendicular to the horizontal surface of the non-planar substrate, more ions irradiate or impinge on the horizontal surface of the non-planar substrate relative to the vertical surface. Thus, the reaction of the ions with the adsorbed silicon species is greater on the horizontal surface than on the vertical surface, thereby preventing complete transformation of the film deposited on the vertical surface, and as a result, significant carbon content is retained in the silicon oxide film disposed on the vertical surface.

[0122] Thus, in some embodiments, the shape-selective deposition process can deposit a silicon oxide film on a vertical surface of a non-planar substrate that includes a higher carbon content than a silicon oxide film on a horizontal surface of the non-planar substrate. For example, the silicon oxide film disposed on the vertical surface can include silicon oxycarbide, or carbon-doped silicon oxide. The etch rate of the deposited silicon oxide film can vary depending on the concentration of carbon in the deposited silicon oxide film. For example, in some embodiments, a silicon oxide film on a vertical surface of a non-planar substrate can have a lower etch rate than a silicon oxide film on a horizontal surface of the non-planar substrate.

[0123] The difference in etch rate of the deposited silicon oxide film due to the shape composition control can be used to selectively remove silicon oxide films disposed on horizontal surfaces relative to silicon oxide films disposed on vertical surfaces. In some embodiments, silicon oxide films disposed on horizontal surfaces can be selectively removed during the cyclic plasma enhanced deposition process by adding another process step that can include contacting the non-planar substrate with another reactive species generated from a plasma generated from a gas including hydrogen gas and a noble gas. In some embodiments, silicon oxide films disposed on horizontal surfaces can be selectively removed by contacting the substrate with an etchant after deposition to selectively remove silicon oxide films on horizontal surfaces of the non-planar substrate relative to silicon oxide films on vertical surfaces of the non-planar substrate. In some embodiments, the selective removal of silicon oxide on horizontal surfaces during the cyclic deposition cycle can be combined with contacting the substrate with an etchant after deposition.

[0124] An exemplary cyclic plasma enhanced deposition process can include a PEALD process that includes one or more cyclic etching steps to selectively remove silicon oxide films disposed on horizontal surfaces of a non-planar substrate, thereby providing a vertical surface selective process.

[0125] 11 illustrates an exemplary PEALD process 1100 that includes a cyclic etching step that selectively removes a silicon oxide film on horizontal surfaces of a non-planar substrate. The exemplary PEALD process 1100 can begin with process block 1110, which includes providing a non-planar substrate into a reaction chamber and heating the substrate to a suitable deposition temperature. Process block 1100 can be identical to process block 210 (FIG. 2), and thus the details of this process will not be repeated for the sake of brevity.

[0126] The exemplary PEALD process 1100 may continue with a cyclic deposition etch stage 1105. In some embodiments, the cyclic deposition etch 1105 may begin with process block 1120, which includes contacting the substrate with a gas-phase reactant including a silicon component, a carbon component, and a hydrogen component. Process block 1120 may be identical to process block 220 (FIG. 2), and thus the details of this process will not be repeated for brevity. The cyclic deposition etch stage 1105 may continue with process block 1130, which includes contacting the substrate with reactive species generated from a plasma generated from a gas including an oxygen precursor and a noble gas. Process block 1130 may be identical to process block 230 (FIG. 2), and thus the details of this process will not be repeated for brevity. Process blocks 1120 and 1130 may be collectively referred to as a "cyclic deposition step" in the exemplary PEALD process 1100.

[0127] The cyclical deposition etch stage 1105 may continue with process block 1140, which includes contacting the substrate with another reactive species generated from a plasma generated from a gas including hydrogen gas and a noble gas. Process block 1140 may be referred to as a "cyclical etch step" in the exemplary PEALD process 1100. In some embodiments, the another reactive species selectively removes silicon oxide films on horizontal surfaces of the non-planar substrate relative to silicon oxide films on vertical surfaces of the non-planar substrate.

[0128] In some embodiments of the present disclosure, the gas used to generate the plasma for the cyclical etching step (process block 1140) can include hydrogen gas and a noble gas. In some embodiments, the noble gas can include at least one of argon, nitrogen, or helium. In some embodiments, the flow ratio of noble gas to hydrogen gas into the reaction chamber can be greater than 2, or greater than 3, or even greater than 4.

[0129] In some embodiments, another reactive species utilized to selectively etch silicon oxide films can be generated by application of RF power to a gas that includes hydrogen gas and a noble gas. For example, the RF power applied to the gas can be less than 500W, or less than 300W, or less than 100W, or between 500W and 50W.

[0130] In some embodiments, the additional reactive species can be generated from an anisotropic plasma by using a parallel plate electrode configuration, where the anisotropic plasma can include a plurality of ions that are accelerated downward toward the substrate in a substantially vertical direction. The anisotropic nature of the plasma can result in a higher ion collision rate on the horizontal surfaces of the non-planar substrate compared to the vertical surfaces of the non-planar substrate, resulting in preferential etching of the silicon oxide film on the horizontal surfaces of the substrate compared to the vertical surfaces of the substrate.

[0131] In some embodiments of the present disclosure, the other reactive species can contact the non-planar substrate for less than 5 seconds, or less than 3 seconds, or even less than 1 second. In some embodiments, the other reactive species can contact the non-planar substrate for between 0.05 seconds and 1 second.

[0132] After the cyclic etching step (process block 1140), the reaction chamber may be purged to remove any excess reactive species and any by-products. In some embodiments, the reaction chamber may be purged for about 0.1 seconds to about 10 seconds, or about 0.3 seconds to about 5 seconds, or even about 0.3 seconds to about 1 second.

[0133] As a non-limiting example, Figure 12 illustrates ellipsometry data showing etched thickness (nanometers) of silicon oxide film versus plasma exposure time (seconds). For example, the noble gas may include argon, the reaction chamber pressure may be about 350 Pascals, the substrate temperature may be about 450°C, and the RF power may be about 100 W. The examination of Figure 12 illustrates a case where about 0.4 nanometers of silicon oxide film is etched with a plasma exposure time of 30 seconds (etch rate of 0.8 nanometers / minute), and a case where about 0.7 nanometers of silicon oxide is etched with a plasma exposure time of 60 seconds (etch rate of 0.7 nanometers / minute).

[0134] The cyclic deposition etch stage 1105 of the exemplary PEALD process 1100 ( FIG. 11 ) may continue with a decision gate 1150 that determines whether the PEALD process 1100 continues or ends. The process block decision gate 1150 is determined based on the thickness of the silicon oxide film formed on the non-planar substrate; for example, if the thickness of the silicon oxide film is insufficient for the desired device structure, the PEALD process 1100 may return to process block 1120, contact the non-planar substrate with a silicon precursor (process block 1120), contact the non-planar substrate with reactive species (process block 1130), contact the substrate with reactive species generated from hydrogen gas (process block 1140), and the unit cycle may be repeated one or more times.

[0135] It should be understood that the sequence of contacting the substrate with a silicon precursor (process block 1120), a reactive species (process block 1130), and another reactive species (process block 1140) may be performed in any possible order. Additionally, one or more process blocks may be repeated one or more times before performing a subsequent process block. Once the silicon oxide film has been formed to a desired thickness, the exemplary PEALD process 1100 may end by process block 1160, and the silicon oxide film may undergo additional processes to form a semiconductor device structure.

[0136] Another schematic of a non-limiting exemplary unit deposition cycle of the vertically selective cyclic PEALD process of the present disclosure is illustrated with reference to Figure 13. As illustrated in Figure 13, and as described with reference to Figure 3, the horizontal axis represents the time parameter and the vertical axis represents the on or off state.

[0137] Briefly, in a first period 1310 (i.e., silicon precursor pulse period), a noble gas and oxygen precursor can be flowed into the reaction chamber with a pulse of silicon precursor, and the silicon precursor can be chemisorbed onto the surface of the non-planar substrate. In a second period 1320 (i.e., purge period), the flow of the noble gas and oxygen precursor can be maintained to purge the reaction chamber while the remaining parameters are off. In a third period 1330 (i.e., RF power period), the flow of the noble gas and oxygen precursor can be maintained, and a pulse of RF power can be applied to the gas to form a plasma containing at least oxygen ions that can react with the chemisorbed silicon to form a silicon oxide film. In a fourth period 1340 (i.e., purge period), all parameters can be off, and the reaction chamber can be purged by evacuating all reactants and by-products to a vacuum pump. In a fifth period 1350 (i.e., the etching period), a pulse of hydrogen gas and a pulse of a noble gas can be supplied to the reaction chamber and an RF power pulse can be applied to the gas to form an anisotropic plasma that selectively etches the silicon oxide film on horizontal surfaces. In a sixth period 1360 (i.e., the purge period), all parameters can be off and the reaction chamber can be purged by exhausting all reactants and by-products to a vacuum pump. In some embodiments, a noble gas flow can be maintained during periods 1340 and 1360 to assist in purging the reaction chamber.

[0138] Another non-limiting example of a vertical surface selective silicon oxide formation process includes shaped deposition of a silicon oxide film, followed by contacting the silicon oxide film with an etchant to selectively remove the silicon oxide film on horizontal surfaces relative to the silicon oxide film on vertical surfaces.

[0139] In more detail, Figure 14 illustrates an exemplary vertically selective process 1400 that can begin with process block 1410, which includes providing a substrate into a reaction chamber and heating the substrate to a suitable deposition temperature. Process block 1410 can be identical to process block 210 (Figure 2) or process block 410 (Figure 4), and therefore the details of this process will not be repeated for brevity. The exemplary vertically selective process 1400 can continue with a cyclic plasma enhanced deposition process that can include a cyclic deposition stage 205 (of the exemplary PEALD process of Figure 2), a cyclic deposition stage 405 (of the exemplary cyclic PECVD process of Figure 4), or a cyclic deposition etch stage 1105 (of the exemplary PEALD process 1100 of Figure 11), all of which have been previously described in detail and therefore will not be repeated for brevity.

[0140] The cyclic plasma enhanced deposition method used to deposit the silicon oxide film described according to the embodiments of the present disclosure can further include morphological composition control of the silicon oxide film as described hereinabove. Thus, in some embodiments, the carbon content of the silicon oxide film disposed on a vertical surface may be greater than the carbon content of the silicon oxide film disposed on a horizontal surface. Such a difference in carbon content results in a difference in the etch rate of the silicon oxide film disposed on the vertical and horizontal surfaces, i.e., the etch rate of the silicon oxide film is lower on the vertical surface, and the difference in etch rate can be utilized to selectively remove the silicon oxide film disposed on the horizontal surface of the non-planar substrate.

[0141] Thus, the exemplary vertically selective silicon oxide formation process 1400 may continue with process block 1420, which includes contacting the silicon oxide film with an etchant to selectively remove silicon oxide films disposed on horizontal surfaces of the non-planar substrate relative to silicon oxide films disposed on vertical surfaces of the non-planar substrate. In some embodiments, the selective etching of the silicon oxide film may completely remove silicon oxide films disposed on horizontal surfaces of the non-planar substrate while maintaining the thickness of the silicon oxide films disposed on vertical surfaces of the non-planar substrate.

[0142] In some embodiments of the present disclosure, the etchant can include a wet chemical etchant or a plasma-based etchant. In some embodiments, the wet chemical etchant can include hydrofluoric acid (HF), such as dilute hydrofluoric acid (1:100). In some embodiments, the plasma-based etchant can include anisotropic plasma etching using fluorine-based chemistries (e.g., CF4, SF6), chlorine-based chemistries (e.g., Cl2, BCl3), or hydrogen gas-based plasma etchants as previously described herein.

[0143] In some embodiments of the present disclosure, the ratio of the etch rate of a silicon oxide film deposited on a vertical surface to the etch rate of a silicon oxide film disposed on a horizontal surface can be greater than 2, or greater than 3, or greater than 5, or even greater than 10. As a non-limiting example, a silicon oxide film deposited according to an embodiment of the present disclosure can have an etch rate of more than 200% on a horizontal surface of a non-planar substrate compared to a silicon oxide film on a vertical surface of the non-planar substrate, i.e., a wet etch rate ratio (WERR) between horizontal silicon oxide and vertical silicon oxide of greater than 2.

[0144] As non-limiting examples of embodiments of the present disclosure, FIGS. 15A-B illustrate an exemplary non-planar substrate after shape-selective deposition of a silicon oxide film by shape control of a silicon oxide composition (FIG. 15A), and an exemplary non-planar substrate after subsequent selective removal of the silicon oxide film located on horizontal surfaces relative to the silicon oxide film located on vertical surfaces by contacting the silicon oxide film with an etchant (FIG. 15B).

[0145] 15A illustrates a non-planar substrate 1500 with a silicon oxide film 1510 deposited according to an embodiment of the present disclosure disposed on the non-planar surface of the substrate 1500. The silicon oxide film includes a thicker silicon oxide film disposed on the horizontal surfaces 1520 and a thinner silicon oxide film disposed on the vertical surfaces 1530. Furthermore, the silicon oxide film disposed on the vertical surfaces 1530 may have a higher carbon concentration compared to the silicon oxide film disposed on the horizontal surfaces 1520, and thus the vertical silicon oxide film 1530 may have a lower etch rate than the horizontal silicon oxide film 1520.

[0146] 15B illustrates the silicon oxide film after contact with an etchant, such as a wet chemical etchant or an anisotropic plasma etchant. As shown in FIG. 15B, the silicon oxide film 1530 disposed on the vertical surfaces maintains a substantial thickness while the silicon oxide film disposed on the horizontal surfaces of the non-planar substrate 1500 has been selectively removed, resulting in vertical surface selective silicon oxide formation.

[0147] As previously disclosed herein, the "selectivity" of a shape-selective process can be expressed as the percentage of material formed on a first planar surface of a non-planar substrate relative to the total amount of material formed on the first and second planar surfaces. In this example of a vertical surface-selective process, the selectivity can be calculated as a percentage ratio of the thickness of the silicon oxide film disposed on the vertical surface compared to the sum of the thicknesses of the silicon oxide films disposed on both the horizontal and vertical surfaces. Thus, in some embodiments of the present disclosure, the shape selectivity may be greater than 50%, or greater than 60%, or greater than 70%, or greater than 80%, or greater than 90%, or even equal to 100%, for the formation of a silicon oxide film disposed on a vertical surface of a non-planar substrate compared to the formation of a silicon oxide film disposed on a horizontal surface of the non-planar substrate.

[0148] The exemplary embodiments of the present disclosure described above are merely examples of embodiments of the present invention, as defined by the appended claims and their legal equivalents, and therefore do not limit the scope of the present invention. Any equivalent embodiments are intended to be within the scope of the present invention. Indeed, various modifications of the present disclosure in addition to those shown and described herein may become apparent to those skilled in the art from the description, including alternative useful combinations of the described elements. Such modifications and embodiments are also intended to fall within the scope of the appended claims. [Explanation of symbols]

[0149] 100 PEALD Equipment 101 Base material 102 Lower Stage 103 Reaction Chamber 104 Upper electrode 105 Transport chamber 106, 107 Exhaust line 111 Inside the reaction chamber 112 The other side of the reaction chamber 113 Circular Duct 114 Separation Plate 120 RF Power 121, 122, 123 Gas lines 124 Seal gas line 200 PEALD Process 205 Cyclic deposition stages 300 Cyclic PECVD Process 310, 510, 610, 710 First period of unit deposition cycle 320, 520, 620, 720 Second period of unit deposition cycle 330, 530, 630, 730 Third period of unit deposition cycle 340, 540, 640, 740 Fourth period of unit deposition cycle 400 Cyclic PECVD Process 405 Cyclic deposition stages 800 Non-planar substrate 802 Trench Structure 804 Horizontal plane 806 Vertical plane 808 Silicon oxide film 810 Silicon oxide film placed on a horizontal surface 812 Silicon oxide film placed on a vertical surface 900 Non-planar silicon substrate 902 Silicon oxide film placed on a horizontal surface 904 Silicon oxide film placed on a vertical surface 906 Non-planar silicon substrate 908 Silicon oxide film placed on a horizontal surface 910 Silicon oxide film placed on a vertical surface 1100 PEALD Process 1105 Cyclic Deposition Etching 1310 First Period 1320 Second Period 1330 Third Period 1340 Fourth Period 1350 Fifth Period 1360 Sixth Period 1400 Vertically Selective Process 1500 Non-planar substrate 1510 Silicon oxide film 1520 Horizontal plane 1530 Vertical plane

Claims

1. A method for forming a shape-selective silicon oxide film by a cyclic plasma enhanced deposition process, the method comprising: providing a non-planar substrate having one or more horizontal surfaces and one or more vertical surfaces into a reaction chamber; contacting the non-planar substrate with a first reactant generated from a first gas including at least a gas-phase reactant including a silicon component, a carbon component, and a hydrogen component while applying discrete pulses of RF power, the first gas being supplied in two or more pulses; contacting the non-planar substrate with a second reactive species generated from a second gas comprising at least an oxygen precursor and an inert gas, the second gas comprising no fluorine component; and selectively forming a silicon oxide film on the horizontal surfaces of the non-planar substrate.

2. The method of claim 1, wherein the gas phase reactant comprises at least one of an alkylsilane, an arylsilane, or an aralkylsilane.

3. The method of claim 1, wherein the gas phase reactant further comprises at least one of a nitrogen component or an oxygen component.

4. The method of claim 3, wherein the gas phase reactant comprises at least one of an alkylalkoxysilane or an alkylaminosilane.

5. The method of claim 1, wherein the cyclic plasma enhanced deposition process includes a cyclic plasma enhanced chemical vapor deposition process.

6. The cyclic plasma enhanced chemical vapor deposition process includes one or more repetitions of a unit deposition cycle, the unit deposition cycle comprising: contacting the nonplanar substrate with the first reactive species and the second reactive species simultaneously; and purging the excess first reactant and the excess second reactant and any reaction by-products.

7. The method of claim 6, wherein the first reactive species and the second reactive species contact the non-planar substrate for less than 1 second.

8. The method of claim 6, wherein the silicon oxide film is shape-selectively formed on an upper horizontal surface of the non-planar substrate.

9. The cyclic plasma enhanced chemical vapor deposition process includes one or more repetitions of a unit deposition cycle, the unit deposition cycle comprising: contacting the nonplanar substrate with the first reactive species and the second reactive species simultaneously; purging the excess first reactant and the excess second reactant and any reaction by-products; contacting the non-planar substrate with a third reactive species generated from an inert gas; and purging away excess third reactant and any reaction by-products.

10. The method of claim 9, wherein the silicon oxide film is selectively deposited on the horizontal surfaces of the non-planar substrate relative to the vertical surfaces of the non-planar substrate.

11. The method of claim 10, wherein shape selectivity is greater than 50% when depositing on the horizontal surface of the non-planar substrate compared to depositing on the vertical surface of the non-planar substrate.

12. The cyclic plasma enhanced chemical vapor deposition process includes one or more repetitions of a unit deposition cycle, the unit deposition cycle comprising: contacting the nonplanar substrate with the first reactive species; contacting the non-planar substrate with a fourth reactive species generated from a gas comprising an inert gas; purging all reactive species and reaction by-products; contacting the nonplanar substrate with the second reactive species; and purging all reactants and reaction by-products.

13. The method of claim 12, wherein the silicon oxide film is selectively deposited on the horizontal surfaces of the non-planar substrate relative to the vertical surfaces of the non-planar substrate.

14. The method of claim 13, wherein shape selectivity is greater than 50% when depositing on the horizontal surface of the non-planar substrate compared to depositing on the vertical surface of the non-planar substrate.

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