Method and apparatus for forming a boron nitride layer

Abstract

Methods and apparatus for forming boron nitride layers using inductively coupled plasma (ICP) are disclosed that address challenges in semiconductor processing, particularly for high aspect ratio structures. The method includes introducing a substrate having a three-dimensional structure into a reaction chamber and performing a plurality of deposition cycles. Each cycle includes providing a gas phase boron precursor and reactive species generated by the ICP. The reactant gas can include nitrogen and hydrogen selected from ammonia, a nitrogen / hydrogen mixture, or hydrazine. The boron precursor can be boron triiodide, boron tribromide, or similar compounds. The process aims to achieve high conformality and film quality by reducing ion bombardment, utilizing high RF power to generate radicals. The method is suitable for semiconductor manufacturing, enhancing uniformity and integrity of boron nitride layers in complex structures.

Description

Technical Field

[0001] This disclosure relates to semiconductor processing technology, and more particularly to the use of inductively coupled plasma to form boron nitride layers for use in high aspect ratio structures. Background Technology

[0002] In semiconductor processing, the formation of certain layers is crucial for various applications, particularly in high aspect ratio structures. Traditional methods often rely on techniques that can lead to problems such as inhomogeneous film deposition and ion bombardment, adversely affecting the quality and conformability of these layers. These challenges are especially pronounced in complex three-dimensional structures, where achieving uniform coverage and maintaining film integrity are critical.

[0003] Due to limitations in plasma generation and precursor delivery, existing techniques struggle to provide the necessary conformality and film quality. Ion bombardment associated with conventional methods can lead to undesirable film properties, such as increased roughness and inhomogeneous crystal structures. Furthermore, the use of certain precursors may be insufficient to address the need for high conformality in high aspect ratio structures. These drawbacks highlight the need for improved methods that can deliver high-quality layers with enhanced uniformity and reduced ion bombardment, thereby meeting the stringent requirements of modern semiconductor applications. Summary of the Invention

[0004] This synopsis is provided to introduce some concepts in a simplified form. These concepts are further described in detail in the following detailed description of exemplary embodiments of this disclosure. This synopsis is not intended to identify key or essential features of the claimed subject matter, nor is it intended to limit the scope of the claimed subject matter.

[0005] In one embodiment, this disclosure includes a method for forming a layer comprising boron and nitrogen on a substrate surface. The method includes introducing the substrate into a reaction chamber, wherein the substrate presents a three-dimensional structure that may include lateral and / or horizontal gaps, and performing multiple deposition cycles. Each deposition cycle includes the steps of: providing a gaseous boron precursor into the chamber and supplying a reactive material generated by an inductively coupled plasma, the plasma being generated by the reactant gas.

[0006] In some embodiments, the reactant gas comprises nitrogen and hydrogen, and may be selected from ammonia, a nitrogen / hydrogen mixture, or hydrazine. In some embodiments, the plasma is formed in a remote plasma unit. In some embodiments, the boron precursor may be a molecule selected from boron triiodide, boron tribromide, boron trichloride, diboron tetrachloride, boron monofluoride, boron trifluoride, or diboron tetrafluoride, with some embodiments specifically employing boron tribromide. The method may also include a purging step after providing the boron precursor and an additional purging after supplying the reactive material. Furthermore, a carrier gas may be used to deliver the boron reactant into the chamber. In some embodiments, the carrier gas comprises argon. In other embodiments, the reactant gas may optionally be used as a carrier and be continuously supplied. In some embodiments, the deposited layer comprises amorphous boron nitride, and the plasma RF power is in the range of 4000 W to 8000 W.

[0007] In another aspect of this disclosure, a semiconductor processing apparatus is provided, comprising a reaction chamber having a substrate support, a heater for heating a substrate, a remote plasma module having a radio frequency power source for generating plasma, a reactant gas source connected to the plasma module, a boron precursor source connected to the reaction chamber via a precursor valve, and a controller. The controller is programmed to perform multiple deposition cycles, each cycle involving introducing a gaseous boron precursor into the reaction chamber and providing a reactive substance generated by the plasma from the reactant gas.

[0008] These and other embodiments will become apparent to those skilled in the art from the following detailed description of certain embodiments with reference to the accompanying drawings; the invention is not limited to any particular embodiment disclosed. Attached Figure Description

[0009] Exemplary embodiments of this disclosure can be more fully understood when considered in conjunction with the following illustrative drawings, and by referring to the detailed description and claims.

[0010] Figure 1 This is a flowchart illustrating a method for forming a boron nitride layer according to an embodiment of the present disclosure.

[0011] Figure 2 This is a schematic diagram illustrating a device according to an embodiment of the present disclosure.

[0012] Figure 3 This is a system diagram illustrating the components involved in forming a boron nitride layer according to an embodiment of the present disclosure.

[0013] It should be understood that the elements in the accompanying drawings are shown for simplicity and clarity and are not necessarily drawn to scale. For example, the dimensions of some elements may be exaggerated relative to other elements to aid in understanding the embodiments shown in this disclosure. Detailed Implementation

[0014] Although certain embodiments and examples are disclosed below, those skilled in the art will understand that the invention extends beyond the specific embodiments and / or uses disclosed herein, as well as their obvious modifications and equivalents. Therefore, the scope of the invention disclosed herein should not be limited to the specific embodiments described below.

[0015] In this disclosure, "gas" can include materials that are gaseous at normal temperature and pressure (NTP), evaporated solids and / or evaporated liquids, and may consist of a single gas or a mixture of gases, depending on the circumstances. Gases other than process gases, i.e., gases introduced without passing through gas distribution components, other gas distribution devices, etc., can be used, for example, to seal the reaction space, and may include sealing gases, such as rare gases.

[0016] The term "precursor" can refer to a compound that participates in a chemical reaction to produce another compound. The term "reactant" is used interchangeably with the term "precursor." The term "inert gas" can refer to a gas that does not participate in a chemical reaction and / or does not become part of the layer to a perceptible extent. Exemplary inert gases include helium and argon and any combination thereof. In some cases, molecular nitrogen and / or hydrogen can be inert gases.

[0017] As used herein, the term "purge" can refer to the process of supplying an inert or substantially inert gas to a reaction chamber between two pulses of reacting gases. For example, a purge gas can be supplied between pulses of two precursors to avoid or at least reduce gas-phase interactions between the two precursors. It should be understood that purging can be carried out temporally, spatially, or both. For example, in the case of temporal purging, purging steps can be used, for instance, in a temporal sequence of supplying a first precursor to the reactor chamber, supplying a purge gas to the reactor chamber, and supplying a second precursor to the reactor chamber, wherein the substrate on which the deposition layer is deposited does not move. In the case of spatial purging, the purging step can be carried out by moving the substrate from a first position (e.g., continuously) supplying the first precursor to a second position (e.g., continuously) supplying the second precursor via a purge gas curtain.

[0018] As used herein, the term "substrate" can refer to any one or more underlying materials, including any one or more underlying materials that can be modified or on which devices, circuits, or films can be formed. A "substrate" can be continuous or discontinuous; rigid or flexible; solid or porous; and combinations thereof. A substrate can be in any form, such as powder, plate, or workpiece. Plate-type substrates can include wafers of various shapes and sizes. Substrates can be made of semiconductor materials, including, for example, silicon, silicon germanium, silicon oxide, gallium arsenide, gallium nitride, and silicon carbide.

[0019] As an example, the powdered substrate may have applications for pharmaceutical manufacturing. The porous substrate may contain polymers. Examples of workpieces may include medical devices (e.g., stents and syringes), jewelry, tooling devices, components for battery manufacturing (e.g., anodes, cathodes, or separators), or components for photovoltaic cells, etc.

[0020] The continuous substrate can extend beyond the boundary of the processing chamber where the deposition process takes place. In some processes, the continuous substrate can move through the processing chamber, allowing the process to continue until the end of the substrate is reached. The continuous substrate can be supplied from a continuous substrate supply system to allow the continuous substrate to be manufactured and output in any suitable form.

[0021] Non-limiting examples of continuous substrates may include sheets, nonwoven films, rolls, foils, fiber webs, flexible materials, bundles of continuous filaments or fibers (e.g., ceramic fibers or polymer fibers). Continuous substrates may also include carriers or sheets on which non-continuous substrates are mounted.

[0022] In some embodiments of this disclosure, the substrate may include a patterned substrate comprising high aspect ratio features, such as, for example, trench structures, vertical gap features, horizontal gap features, and / or fin structures. For example, the substrate may include one or more substantially vertical gap features and / or one or more substantially horizontal gap features. The term "gap feature" can refer to an opening or cavity disposed between relatively inclined sidewalls or two protrusions extending vertically from the substrate surface, or between relatively inclined sidewalls of a recess extending vertically into the substrate surface. Such a gap feature may be referred to as a "vertical gap feature." 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, where "greater than" as used in this example refers to a greater distance than the height of the gap feature.

[0023] As used herein, the terms “film” and / or “layer” can refer to any continuous or discontinuous structure and material, such as materials deposited by the methods disclosed herein. For example, films and / or layers can include two-dimensional materials, three-dimensional materials, nanoparticles, or even partial or complete molecular layers or partial or complete atomic layers or atomic and / or molecular clusters. Films or layers can include materials or layers with pinholes, which can be at least partially continuous.

[0024] As used herein, "structure" can be or includes a substrate as described herein. A structure may include one or more layers covering the substrate, such as one or more layers formed according to the methods of this disclosure.

[0025] The term "cyclic deposition process" or "cyclic deposition process" can refer to the sequential introduction of precursors (and / or reactants) into a reaction chamber to deposit a layer on a substrate, and includes processing techniques such as atomic layer deposition (ALD), cyclic chemical vapor deposition (cyclic CVD), and hybrid cyclic deposition processes that include both ALD and cyclic CVD components. This method may include purging steps between the introduction of precursors.

[0026] The term "atomic layer deposition" can refer to a vapor phase deposition process in which deposition cycles, typically multiple consecutive, are performed in a processing chamber. As used herein, the term atomic layer deposition is also intended to include processes specified by related terms (such as chemical vapor deposition) when performed with alternating pulses of precursor / reactive gases and (multiple) purging gases (e.g., inert carrier gases).

[0027] Typically, for an ALD process, during each cycle, a precursor is introduced into the reaction chamber and chemisorbed onto the deposition surface (e.g., a substrate surface that may include previously deposited material from a previous ALD cycle or other materials), forming a monolayer or submonolayer material that does not readily react with further precursors (i.e., a self-limiting reaction). Subsequently, in some cases, a reactant (e.g., another precursor or reactive gas) may be introduced into the processing chamber to convert the chemisorbed precursor into the desired material on the deposition surface. The reactant is capable of further reacting with the precursor. During one or more cycles, such as during each step of each cycle, a purging step may be used to remove any excess precursor from the processing chamber and / or any excess reactant and / or reaction byproducts from the reaction chamber.

[0028] As used herein, the term “plasma-enhanced atomic layer deposition” (PEALD) may refer to an ALD process in which one or more precursors, reactants and / or other gases are exposed to plasma to form an excitation material.

[0029] As used herein, “boron nitride” can be a material represented by a chemical formula comprising boron and nitrogen. In some embodiments, boron nitride may not include elements other than boron and nitrides in significant proportions. In some embodiments, boron nitride comprises BN. In some embodiments, boron nitride may consist substantially of BN. In some embodiments, boron nitride may consist of boron nitride. A layer composed of boron nitride may include acceptable amounts of impurities, such as hydrogen, carbon, iodine, bromine, etc., which may originate from one or more precursors used to deposit the boron nitride.

[0030] As used herein, the term "comprising" means including certain features, but does not exclude the presence of other features, provided they do not render the claim unfeasible. In some embodiments, the term "comprising" includes "consisting of".

[0031] As used herein, the term "composed of" indicates that no other features exist in the apparatus / method / product besides the features following the wording. When the term "composed of" is used to refer to a compound, substance, or composition of substances, it indicates that the compound, substance, or composition of substances contains only the listed components. Similarly, when the term "essentially composed of" is used to refer to a compound, substance, or composition of substances, it indicates that the compound, substance, or composition of substances contains the listed components, but may also contain trace elements and / or impurities that do not materially affect the properties of the compound, substrate, or composition of substances. Nevertheless, in some embodiments, in addition to the listed components, the chemical compound, substrate, or composition of substances may also contain other components as trace elements or impurities.

[0032] In this specification, it will be understood that the terms "on" or "above" may be used to describe relative positional relationships. Another element, film, or layer may be directly on the mentioned layer, or another layer (intermediate layer) or element may be inserted between them, or a layer may be disposed on the mentioned layer but not completely cover the surface of the mentioned layer. Therefore, unless the term "directly" is used alone, the terms "on" or "above" will be interpreted as relative concepts. Similarly, it will be understood that the terms "below," "under," or "beneath" will be interpreted as relative concepts.

[0033] The term "basic" applied to film-forming compositions, methods, systems, or structures generally refers to a proportion of a value, property, characteristic, etc., or conversely, to its absence, i.e., at least about 70%, at least about 80%, at least about 90%, at least about 95%, at least about 97%, at least about 98%, at least about 99%, at least about 99.5%, at least about 99.9% or more, or any proportion between about 70% and about 100%. In some embodiments, the term "basic" means a proportion of about 90%, about 95%, about 97%, about 98%, about 99%, about 99.5%, or about 99.9%.

[0034] The term "basic" when applied to compositions, methods, or systems generally means that the addition of components does not substantially alter the properties and / or function of the composition, method, or system.

[0035] Furthermore, in this disclosure, any two numbers of a variable may constitute a feasible range of the variable, and any indicated range may include or exclude endpoints. Additionally, any value of the indicated variable (whether or not it is indicated by “about”) may refer to an exact value or an approximate value and include equivalents, and may refer to an average, median, representative value, multi-value, etc. Furthermore, in this disclosure, the terms “comprising,” “consisting of,” and “having” may independently mean “generally or broadly comprising,” “including,” “substantially composed of,” or “composed of” in some embodiments. The meaning of any definition in this disclosure does not necessarily exclude the common and customary meaning in some embodiments.

[0036] Now turn to the attached image. Figure 1 A method 100 according to an exemplary embodiment of the present disclosure is illustrated. Method 100 can be used to form boron nitride on the surface of a substrate. In the illustrated example, method 100 includes the steps of: providing a substrate 102 in a reaction chamber, providing a boron precursor 104 to the reaction chamber, and providing a reactant 106 to the reaction chamber.

[0037] During step 102, a substrate is provided in the reaction chamber. The reaction chamber used during step 102 may be or include the reaction chamber of a chemical vapor deposition reactor system configured to perform a deposition process. The deposition process may be a chemical vapor deposition process and / or a circulating deposition process. The reaction chamber may be a standalone reaction chamber or part of a cluster tool. The reaction chamber may be a batch processing tool. In some embodiments, a flow reactor may be used. In some embodiments, a spray head type reactor may be used. In some embodiments, a spatially partitioned reactor may be used. In some embodiments, a single-wafer reactor capable of high-volume manufacturing may be used. In other embodiments, a batch reactor comprising multiple substrates may be used. For embodiments in which a batch reactor is used, the number of substrates may range from 10 to 200, or 50 to 150, or even 100 to 130. The reactor may be configured as a thermal reactor—without a plasma excitation device. Alternatively, the reactor may include a direct and / or remote plasma device.

[0038] In some embodiments, the exposed surfaces of the substrate may be pretreated to provide reactive sites, if desired. In some embodiments, a separate pretreatment step is not required. In some embodiments, the substrate is pretreated, for example, by exposing the substrate surface to a pretreatment plasma to provide the desired surface termination.

[0039] In some embodiments of this disclosure, the substrate disposed within the reaction chamber can be heated to a desired deposition temperature for subsequent deposition. For example, the substrate can be heated to temperatures less than about 600°C, less than about 500°C, less than about 450°C, less than about 400°C, less than about 350°C, less than about 300°C, less than about 250°C, or even less than about 200°C. In some embodiments of this disclosure, the substrate temperature during step 102 can be greater than room temperature, between about 300°C and about 600°C, or between about 350°C and about 550°C, or between about 200°C and about 400°C. Lower temperatures may be preferred for plasma-assisted processes, while higher temperatures may be desirable for thermal deposition processes. Temperatures during steps 104 and / or 106 can also be within these ranges.

[0040] In addition to controlling the substrate temperature, the pressure in the reaction chamber can also be adjusted to enable the deposition of the desired boron nitride. In some embodiments, the pressure can be controlled between about 0.5 Torr and about 50 Torr (e.g., for heat treatment) or between about 1 Torr and about 10 Torr (e.g., for plasma enhancement processes). The pressure during steps 104 and / or 106 can also be within these ranges.

[0041] Once the substrate temperature has been set to the desired deposition temperature and the pressure in the reaction chamber has been adjusted as needed, method 100 can proceed to steps 104 and 106. When method 100 includes a CVD process, steps 104 and 106 can overlap. When method 100 includes a cyclic process, steps 104 and 106 can be performed sequentially, with an intermediate purge step between steps 104 and 106. During step 104, a boron precursor is supplied to the reaction chamber. In the case of cyclic deposition, the boron precursor can be pulsed into the reaction chamber. The term "pulse" can be understood to include supplying the precursor to the reaction chamber for a predetermined amount of time. Unless otherwise stated, the term "pulse" does not limit the length or duration of the pulse, and the pulse can be of any length. In some embodiments, in addition to the boron precursor, a gas may be continuously supplied to the reaction chamber during the cyclic deposition process. In some embodiments, the gas may include a gas used to generate reactive substances used during a phase of the PEALD process, and may also be used as a purge gas to remove excess reactants, reactive substances, and reaction byproducts from the reaction chamber.

[0042] Following the initial surface treatment, a boron precursor pulse can be supplied to the substrate, if needed or desired. According to some embodiments, the boron precursor can be supplied to the reaction chamber along with a carrier gas flow. In some embodiments, the boron precursor may comprise a volatile boron substance that reacts with the substrate surface. The boron precursor pulse can self-saturate the substrate surface, preventing excess components of the boron precursor pulse from further reacting with the molecular layer formed by this process.

[0043] The boron precursor pulse is preferably supplied as a gaseous reactant. For the purposes of this disclosure, the boron precursor gas may be considered "volatile" if the substance exhibits sufficient vapor pressure under processing conditions to deliver the substance to the substrate surface at a sufficient concentration to saturate the exposed surface.

[0044] In some embodiments, the gaseous boron precursor includes boron halide, borane, cycloborane, or organoborane.

[0045] In some embodiments of this disclosure, the gaseous boron precursor comprises boron and at least one halogen selected from iodine and bromine. In some cases, the boron precursor does not include fluorine and / or chlorine. According to some embodiments of this disclosure, the boron precursor consists of boron and one or more of iodine and bromine. In some embodiments, the boron precursor comprises molecules selected from boron triiodide, boron tribromide, boron trichloride, diboron tetrachloride, boron monofluoride, boron trifluoride, and diboron tetrafluoride. For example, the boron precursor may be or include boron triiodide (BI3) and / or boron tribromide (BBr3).

[0046] In some embodiments, the gaseous boron precursor comprises boron and hydrogen. In some embodiments, the boron precursor comprises borane, diborane, tetraborane, pentaborane, decaborane, and borane-ammonia complex.

[0047] In some specific embodiments, as disclosed herein, the boron precursor may be specified as being represented by the following general formula (I):

[0048] (I)

[0049] Among them, R 1 R 2 R 3 R 4 R 5 R 6 Each is independently selected from hydrogen, halogen, alkyl, alkenyl, and alkoxy.

[0050] The term "halogenated" or "halogen" as a group or part of a group is generally used for fluorine (F), chlorine (Cl), bromine (Br), and iodine (I).

[0051] The term "alkyl" as a group or part of a group refers to the formula C n H 2n+1The alkyl group is a hydrocarbon group, where n is a number greater than or equal to 1. The alkyl group can be straight-chain or branched and can be substituted as shown herein. Typically, the alkyl groups disclosed herein contain 1 to 20 carbon atoms, preferably 1 to 10 carbon atoms, more preferably 1 to 8 carbon atoms, more preferably 1 to 6 carbon atoms, and more preferably 1 to 4 carbon atoms. When a subscript is used herein following a carbon atom, the subscript indicates the number of carbon atoms that the named group may contain. For example, the term "C1-20 alkyl," as a group or part of a group, refers to the formula C1-20 alkyl. n H 2n+1 The alkyl group, where n is a number from 1 to 20. Therefore, for example, "C1-8 alkyl" includes all straight-chain or branched alkyl groups having 1 to 8 carbon atoms, and thus includes methyl, ethyl, n-propyl, isopropyl, butyl and their isomers (e.g., n-butyl, isobutyl, and tert-butyl); pentyl and its isomers, hexyl and its isomers, etc. "Substituted alkyl" refers to an alkyl group that is substituted at any available junction with one or more substituents (e.g., 1 to 3 substituents, such as 1, 2, or 3 substituents).

[0052] When the suffix "alkylene" is used in conjunction with alkyl, it is called "alkylenetriene," which is intended to indicate that an alkyl group, as defined herein, has two single bonds as points of attachment to other groups. As used herein, the term "alkylenetriene" itself, or as part of another substituent, is also called "alkyldiyl," referring to a divalent alkyl group, i.e., having two single bonds for attachment to two other groups. Alkylenetrienes can be straight-chain or branched and can be substituted as shown herein. Non-limiting examples of alkylene groups include methylene (-CH2-), ethylene (-CH2-CH2-), methylmethylene (-CH(CH3)-), 1-methyl-ethylene (-CH(CH3)-CH2-), n-propylene (-CH2-CH2-CH2-), 2-methylpropylene (-CH2-CH(CH3)-CH2-), 3-methylpropylene (-CH2-CH2-CH(CH3)-), n-butylene (-CH2-CH2-CH2-CH2-), 2-methylbutylene (-CH2-CH(CH3)-CH2-CH2-), 4-methylbutylene (-CH2-CH2-CH2-CH(CH3)-), pentylene and its chain isomers, and hexylene and its chain isomers.

[0053] The term "alkenyl" as a group or part of a group refers to an unsaturated hydrocarbon group, which may be straight-chain or branched and contains one or more carbon-carbon double bonds. Typically, the alkenyl groups disclosed herein contain 3 to 20 carbon atoms, preferably 3 to 10 carbon atoms, and more preferably 3 to 8 carbon atoms. When a subscript is used herein following a carbon atom, the subscript indicates the number of carbon atoms that the named group may contain. Examples of C3-20 alkenyl groups are vinyl, 2-propenyl, 2-butenyl, 3-butenyl, 2-pentenyl and its isomers, 2-hexenyl and its isomers, 2,4-pentadienyl, etc.

[0054] The term "alkoxy" or "alkyloxy", as a group or part of a group, refers to a group having the formula -OR b The group, wherein R b It is an alkyl group as defined above. Non-limiting examples of suitable alkoxy groups include methoxy, ethoxy, propoxy, isopropoxy, butoxy, isobutoxy, sec-butoxy, tert-butoxy, pentoxy, and hexoxy.

[0055] In the presence of alkylene groups, the linkages to the molecular structure forming part of them can be through common carbon atoms or different carbon atoms. To illustrate this, using the asterisk nomenclature of this disclosure, the C3 alkylene group can be, for example, *-CH2CH2CH2-*, *-CH(-CH2CH3)-*, or *-CH2CH(-CH3)-*.

[0056] In some embodiments, as specified in the methods disclosed herein, for one or more boron precursors represented by general formula (I), the alkyl group is a C1-8 alkyl group, more particularly a C1-4 alkyl group. More specifically, the alkyl group is a C1, C2, C3, C4, C5, C6, C7 and / or C8 alkyl group.

[0057] In some embodiments, as specified in the methods disclosed herein, for one or more boron precursors represented by general formula (I), the alkenyl group is a C2-8 alkenyl group, more particularly a C2-4 alkenyl group. More specifically, the alkenyl group is a C2, C3, C4, C5, C6, C7, and / or C8 alkenyl group.

[0058] In some embodiments, as specified in the methods disclosed herein, for one or more boron precursors represented by general formula (I), the alkoxy group is a C1-8 alkoxy group, more particularly a C1-4 alkoxy group. More specifically, the alkoxy group is a C1, C2, C3, C4, C5, C6, C7, and / or C8 alkoxy group.

[0059] In some embodiments, this disclosure specifies that R 1 R 2 R 3 R 4 R 5 R 6Each is independently selected from hydrogen, halogen, C1-8 alkyl, C2-8 alkenyl and C1-8 alkoxy.

[0060] In some embodiments, this disclosure specifies that R 1 R 2 R 3 R 4 R 5 R 6 Each is independently selected from hydrogen, halogen, C1-4 alkyl, C2-4 alkenyl, and C1-4 alkoxy.

[0061] In certain embodiments, as specified in the methods disclosed herein, one or more boron precursors may include cycloborazane or substituted cycloborazane.

[0062] In some embodiments, the boron precursor comprises an organoborane, including alkylboranes or alkylaminoboranes. The boron precursor may comprise molecules selected from: trimethylborane, triethylborane, 3-tri-(dimethylamino)borane, dimethylamineborane, and triethylamineborane.

[0063] In some embodiments of this disclosure, the boron precursor can be pulsed into the reaction chamber for a duration of 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. Furthermore, during the contact between the substrate and the boron precursor, the flow rate of the boron precursor can be less than 20 slm, or less than 10 slm, or less than 7 slm, or less than 5 slm, or even less than 3 slm. Additionally, during the contact between the substrate and the boron precursor, the flow rate of the boron precursor can range from about 0.05 to 10 slm, about 0.1 to 7 slm, or about 0.1 to about 5 slm. In some embodiments, argon is used as the carrier gas when the boron precursor is supplied to the reaction chamber. When using argon as the carrier gas, it has been noted that a wider range of pressures can be provided during the plasma pulse. In some embodiments, a reactant gas is used as the carrier gas when the boron precursor is supplied to the reaction chamber.

[0064] In some embodiments, excess boron precursor can be purged by stopping the flow of the gaseous boron precursor while continuing to flow the carrier gas, purge gas, or gas mixture for a sufficient time to diffuse from the reaction chamber or to purge excess reactants and reactant byproducts (if any). In some embodiments, excess boron precursor can be purged by means of one or more inert gases (e.g., nitrogen, helium, or argon) that can flow throughout the cyclic deposition steps 104 and 106.

[0065] In some embodiments, the boron precursor may be purged from the reaction chamber for a period of 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. The provision and removal of the boron precursor may be considered as the first or “boron stage” of exemplary method 100.

[0066] After the excess boron precursor and any reaction byproducts in the reaction chamber have been purged, the cyclic deposition stage 108 of the exemplary PEALD process 100 can continue to a second stage via process block 106, which includes contacting the substrate with a reactive material generated by a plasma containing a gas.

[0067] In the second stage, a second reactant comprising a reactive substance generated by plasma is provided to the substrate. In some embodiments, the plasma based on the reactant is generated by a gas containing the reactant. In some embodiments, the reactant may comprise nitrogen and hydrogen. In some embodiments, the reactant may comprise ammonia. In some embodiments, the reactant may comprise a nitrogen / hydrogen mixture. In some embodiments, the reactant may comprise hydrazine.

[0068] For example, nitrogen-based plasma can be generated by applying RF power of about 1000W to 10000W, or about 3000W to about 9000W, or about 4000W to about 8000W, or about 5000W to about 7000W. In some embodiments, the plasma can be generated remotely. In some embodiments, a remote plasma unit can be used to generate the plasma. In some embodiments, the plasma is inductively coupled (ICP) plasma. ICP allows the generation of high concentrations of free radicals, which can drive the chemical reactions necessary for layer deposition. ICP also minimizes ion bombardment, reducing damage to the substrate and improving the conformability and quality of the deposited film, while maintaining good growth per cycle. This makes ICP suitable for applications requiring precise control of film properties, such as forming boron nitride layers in high aspect ratio structures.

[0069] In some embodiments, the reactive material generated by the plasma can contact the substrate for a period of time between about 0.5 seconds and about 20 seconds, or about 1 second and about 15 seconds, or even about 3 seconds and about 10 seconds. In some embodiments, the reactive material generated by the plasma can contact the substrate for a period of time between about 2 seconds and 12 seconds.

[0070] After a sufficient period of time to fully saturate the previously absorbed molecular layer and react with the reactant-based plasma pulse, any excess reactants and reaction byproducts can be removed from the reaction chamber. Similar to the removal of the first reactant (i.e., the gaseous boron precursor), this step may involve stopping the production of reactive material and continuing the flow of an inert gas (e.g., a gas containing nitrogen, helium, and, in some embodiments, argon). The inert gas flow can be sufficient to allow excess reactive material and volatile reaction byproducts to diffuse out of and be purged from the reaction chamber. For example, the purging process may utilize a time period between about 0.1 seconds and about 10 seconds, or about 0.1 seconds and about 4.0 seconds, or even between about 0.1 seconds and about 0.5 seconds. The supply and removal of nitrogen-based plasma together represent Figure 1The second stage of the exemplary boron nitride PEALD process 100, namely the reactive material stage 106.

[0071] The method of alternately and sequentially contacting the substrate with a gaseous boron precursor and with a reactive substance generated from a gas containing a nitrogen precursor can constitute a unit deposition cycle. In some embodiments of this disclosure, the exemplary PEALD method 100 may include repeating a unit deposition cycle once or multiple times 108. For example, the cyclic deposition phase 108 of the exemplary PEALD process 100 may continue regardless of whether the desired thickness is not achieved, for example, if the thickness of the boron nitride film is insufficient for the desired device structure, then the PEALD process 100 may return to process block 104, and the processes of contacting the substrate with the boron precursor and contacting the substrate with the reactants (process block 106) may be repeated once or multiple times. For example, if the thickness of the boron nitride is less than the thickness required for a particular application, steps 104 and 106 may be repeated once or multiple times. In some embodiments, the method includes at least 1 cycle to at most 1000 cycles, or at least 2 cycles to at most 800 cycles, or at least 3 cycles to at most 700 cycles, or at least 4 cycles to at most 600 cycles, or at least 5 cycles to at most 500 cycles, or at least 10 cycles to at most 400 cycles, or at least 20 cycles to at most 300 cycles. In some embodiments, the method includes at most 1000 cycles, or at most 900 cycles, or at most 800 cycles, or at most 700 cycles, or at most 600 cycles, or at most 500 cycles, or at most 400 cycles, or at most 300 cycles, or at most 200 cycles, or at most 100 cycles, or at most 50 cycles, or at most 40 cycles, or at most 30 cycles, or at most 20 cycles, or a single cycle.

[0072] Once the boron nitride film has been deposited to the desired thickness, the exemplary PEALD process 100 can be terminated, and the boron nitride film can undergo further processes to form a semiconductor device structure.

[0073] Although the PEALD cycle is generally referred to herein as beginning with boron stage 104, it is conceivable that in other embodiments the cycle may begin with reactive material stage 106. Those skilled in the art will recognize that the first precursor phase typically reacts with the end phase left by the last phase in the previous cycle. Therefore, while no reactant may have previously been absorbed onto the substrate surface or present in the reaction chamber if the reactive material is the first stage in the PEALD cycle, the reactive material stage will effectively follow the boron stage in subsequent cycles. In some embodiments, one or more different PEALD cycles are provided during the deposition process.

[0074] In some embodiments, the growth rate of boron nitride film per deposition cycle can be greater than 0.01 nm / cycle, or greater than 0.02 nm / cycle, or greater than 0.03 nm / cycle. In some embodiments, at a deposition temperature greater than 250°C, the growth rate of boron nitride film per deposition cycle can be between about 0.01 and about 0.1 nm / cycle.

[0075] In some embodiments, boron nitride can be deposited to a thickness of about 1 nanometer to about 50 nanometers, or about 5 nanometers to about 30 nanometers, or about 5 nanometers to about 20 nanometers, or about 1 nanometer to 10 nanometers. These thicknesses can be achieved in feature sizes (widths) of less than about 100 nanometers, or less than about 50 nanometers, or less than about 30 nanometers, or less than about 20 nanometers, or even less than about 10 nanometers.

[0076] In some embodiments of this disclosure, boron nitride can be deposited on a three-dimensional structure, such as a non-planar substrate containing high aspect ratio features. In some embodiments, in structures with an aspect ratio (height / width) greater than about 2, greater than about 5, greater than about 10, greater than about 25, greater than about 50, or even greater than about 100, the step coverage of the boron nitride film can be equal to or greater than about 50%, or greater than about 60%, or greater than about 70%, or greater than about 80%, or greater than about 90%, or greater than about 95%, or greater than about 98%, or greater than about 99%, or greater.

[0077] Figure 2 The structure / part of a device 200 according to another example of this disclosure is shown. The device or structure 200 includes a substrate 202 and a boron nitride layer (or boron nitride layer) 204 covering the boron nitride layer formed on the substrate 202.

[0078] Substrate 202 may be or include any substrate material described herein. Boron nitride layer 204 may be formed according to the methods described herein. When layer 204 is formed using a cyclic deposition process, the concentrations of boron, nitrogen, and / or other components (e.g., carbon, hydrogen, etc.) in boron nitride layer 204 may vary from the bottom to the top of boron nitride layer 204, for example, by controlling the amount of boron precursors and / or reactants and / or the corresponding pulse time or number of pulses during one or more deposition cycles. In some cases, boron nitride layer 204 may have a stoichiometric composition. Various properties of boron nitride layer 204 can be altered by changing the amount of boron, nitrogen, and / or other compounds in the layer or during the deposition cycle.

[0079] In some embodiments, boron nitride deposited according to the methods disclosed herein exhibits better etch resistance compared to equivalent boron nitride films deposited via conventional processes. For example, the wet etch rate ratio (WERR) of the boron nitride film deposited by the methods of this disclosure relative to the wet etch rate of thermally oxidized silicon in dilute hydrofluoric acid (1:100) can be less than 1.0, or less than 0.5, or less than 0.4, or less than 0.2, or less than 0.1, or between about 0.1 and about 1.0.

[0080] In some embodiments of this disclosure, the wet etching of boron nitride deposited according to the methods disclosed herein in dilute hydrofluoric acid (1:100) (at room temperature) can be less than 1.5 nm / min, or less than 1.0 nm / min, or even less than 0.8 nm / min.

[0081] In some embodiments of this disclosure, boron nitride deposited according to the methods disclosed herein can have a thickness of less than 1E-6A / cm at 10 nm. 2 Leakage values ​​of 2MV / cm, for example, less than 1E-8A / cm. 2 @2MV / cm.

[0082] In some embodiments of this disclosure, boron nitride is essentially composed of boron and nitrogen. In some embodiments, the boron nitride film may comprise carbon-doped boron nitride.

[0083] In some cases, the boron nitride layer 204 is amorphous. In other cases, the boron nitride layer 204 is not polycrystalline.

[0084] The dielectric constant of the boron nitride layer 204 can be less than 4, less than 3.7, or less than 3.5. The dielectric constant can be greater than 2, greater than 2.5, or greater than 2.7.

[0085] Figure 3 A system 300 according to another exemplary embodiment of the present disclosure is illustrated. The system 300 can be used to perform the methods described herein and / or form structural or device portions as described herein.

[0086] In the illustrated example, system 300 includes one or more reaction chambers 314, a boron precursor source 302 in fluid communication with reaction chamber 314 via a first valve 303, a reactant source 304 in fluid communication with reaction chamber 314 via a second valve 305, a third gas source (e.g., a carrier gas and / or purge gas source) 306 in fluid communication with reaction chamber 314 via a third valve 307; an exhaust source 316; and a controller 318. System 300 may include a remote plasma source 320 to excite gases from one or more sources 302-306.

[0087] The reaction chamber 314 may include any suitable reaction chamber, such as an ALD or CVD reaction chamber. The reaction chamber 314 may include a gas distribution system 322 (e.g., a spray nozzle) and a base 324 for holding the substrate.

[0088] Boron precursor source 302 may include a container and one or more boron precursors as described herein (alone or mixed with one or more carrier gases (e.g., inert gases)). Reactant source 304 may include a container and one or more reactants as described herein (e.g., nitrogen reactants)—alone or mixed with one or more carrier gases. A third gas source 306 may include one or more inert gases and / or carrier gases as described herein. Although three gas sources 302-306 are shown, system 300 may include any suitable number of gas sources. Gas sources 302-306 may be connected to reaction chamber 314 via lines 308-312, each of which may include a flow controller, valve, heater, etc.

[0089] The exhaust source 316 may include one or more vacuum pumps.

[0090] Controller 318 may include electronic circuitry and software to selectively operate valves, manifolds, heaters, pumps, and other components included in system 300. Such circuitry and components may be operable to introduce precursors, reactants, and purge gases from corresponding sources 302-306. Controller 318 may control the timing of gas pulse sequences, the temperature of the substrate and / or reaction chamber, the pressure within the reaction chamber, and various other operations to provide appropriate operation of system 300. Controller 318 may include control software to electrically or pneumatically control valves to control the inflow and outflow of precursors, reactants, and purge gases from reaction chamber 314. Controller 318 may include modules, such as software or hardware components like FPGAs or ASICs, to perform certain tasks. Modules may advantageously be configured to reside on addressable storage media of the control system and configured to perform one or more processes. For example, controller 318 may be operatively connected to first valve 303 and second valve 305 and configured and programmed to control: supplying boron precursor in reaction chamber and supplying nitrogen-containing reactants to reaction chamber, thereby depositing boron nitride on substrate.

[0091] Other configurations of system 300 are possible, including different numbers and types of precursor and reactant sources, as well as purge gas sources. Furthermore, it should be understood that numerous arrangements of valves, conduits, precursor sources, and purge gas sources exist to achieve the objective of selectively supplying gases to reaction chamber 314. Additionally, for the sake of simplicity, many components have been omitted in the schematic diagram of the apparatus, and these components may include, for example, various valves, manifolds, purifiers, heaters, containers, vents, and / or bypasses.

[0092] During operation of the deposition system 300, a substrate, such as a semiconductor wafer (not shown), is transferred from, for example, a substrate processing system to a reaction chamber 314. Once the substrate is transferred to the reaction chamber 314, one or more gases (e.g., precursors, reactants, carrier gases, and / or purge gases) from gas sources 302-306 are introduced into the reaction chamber 314 to deposit boron nitride.

[0093] The illustrations presented herein are not intended to be actual views of any particular material, structure, or device, but are merely idealized representations used to describe embodiments of this disclosure.

[0094] The specific embodiments shown and described are illustrative of the invention and its best mode, and are not intended to limit the scope of aspects and embodiments in any way. In fact, for the sake of brevity, conventional manufacturing, connection, fabrication, and other functional aspects of the system may not be described in detail. Furthermore, the connecting lines shown in the figures are intended to represent exemplary functional relationships and / or physical connections between various elements. Many alternative or additional functional relationships or physical connections may exist in the actual system, and / or may not exist in some embodiments.

[0095] It should be understood that the configurations and / or methods described herein are exemplary in nature, and these specific embodiments or examples herein should not be considered limiting, as many variations are possible. The particular routines or methods described herein may represent one or more of any number of processing strategies. Therefore, the various actions shown may be performed in the order shown, in a different order, or in some cases omitted.

[0096] The subject matter of this disclosure includes all novel and non-obvious combinations and sub-combinations of various processes, systems and configurations, as well as other features, functions, actions and / or properties disclosed herein, and any and all equivalents thereof.

Claims

1. A method for forming a layer comprising boron and nitrogen on the surface of a substrate, the method comprising: A substrate is provided into the reaction chamber, wherein the substrate comprises a 3D structure; and Multiple deposition cycles are performed, and the deposition cycles include: A gaseous boron precursor is provided in the reaction chamber; Reactive substances generated by plasma are supplied to the reaction chamber; the plasma is produced by the reactant gas. The plasma is an inductively coupled plasma.

2. The method according to claim 1, wherein, The reactant gases include nitrogen and hydrogen.

3. The method according to claim 2, wherein, The reactant gases are selected from ammonia (NH3), nitrogen / hydrogen mixtures (N2 / H2), and hydrazine (H2H4).

4. The method according to any one of the preceding claims, wherein, The 3D structure of the substrate includes at least one of a lateral gap and a horizontal gap.

5. The method according to any one of the preceding claims, wherein, The plasma is formed in a remote plasma unit.

6. The method according to any one of the preceding claims, wherein, The boron precursor is selected from boron halides, boranes, cycloboranes, and organoboranes.

7. The method according to claim 6, wherein, The boron halide includes molecules selected from the following: boron triiodide, boron tribromide, boron trichloride, diboron tetrachloride, boron monofluoride, boron trifluoride, and diboron tetrafluoride.

8. The method according to claim 6, wherein, The borane includes molecules selected from the following: borane, diborane, tetraborane, pentaborane, decaborane, and borane-ammonia complexes.

9. The method according to claim 6, wherein, The cycloborazane includes molecules represented by the following general formula (I): (I) Among them, R 1 R 2 R 3 R 4 R 5 R 6 Each is independently selected from hydrogen, halogen, alkyl, alkenyl, and alkoxy.

10. The method according to claim 6, wherein, The organoboranes include molecules selected from the following: trimethylborane, triethylborane, 3-tri-(dimethylamino)borane, dimethylamineborane, and triethylamineborane.

11. The method according to any one of the preceding claims, wherein, The method further includes a purging step following the step of providing the boron precursor into the reaction chamber.

12. The method according to any one of the preceding claims, wherein, The method further includes a purging step following the step of providing the reactive material into the reaction chamber.

13. The method according to any one of the preceding claims, wherein, The method further includes using a carrier gas to supply the boron precursor into the reaction chamber.

14. The method according to claim 13, wherein, The carrier gas includes argon.

15. The method according to any one of claims 1 to 12, wherein, The reactant gas acts as a carrier gas.

16. The method according to any one of claims 13 to 15, wherein, The carrier gas and / or reactant gas are continuously supplied to the reaction chamber.

17. The method according to any one of the preceding claims, wherein, The layer containing boron and nitrogen comprises amorphous boron nitride.

18. The method according to any one of the preceding claims, wherein, The plasma RF power is in the range of 1000W to 10000W.

19. A semiconductor processing apparatus, comprising: The reaction chamber includes a substrate support for supporting the substrate; A heater, which is constructed and arranged to heat the substrate in the reaction chamber; A remote plasma module, comprising a radio frequency power supply configured and arranged to generate plasma; The reactant gas source is in fluid communication with the plasma module; A boron precursor source, which is fluidly connected to the reaction chamber via one or more precursor valves; and A controller, operably connected to a plasma module and one or more precursor valves, and provided with a non-transitory computer-readable medium, is programmed to cause the semiconductor processing apparatus to perform multiple deposition cycles, the deposition cycles including: providing a gaseous boron precursor in a reaction chamber; And the reactive substances generated by plasma are supplied to the reaction chamber, the plasma being generated by the reactant gas.

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