Embodiments of the disclosure relate to the field of microelectronic device design and fabrication. More particularly, the disclosure relates to methods for forming microelectronic devices (e.g., semiconductor devices, such as memory devices) having conductive structures comprising titanium nitride (TiN), to relate electronic apparatus, and to related systems.
Integrated circuit designs are continually being scaled down in size in efforts to increase the number of electronic devices that can occupy a given footprint, to reduce power consumption, and to increase operational speed. With each passing generation, electronic devices tend to get smaller and more densely packed, raising a number of challenges for integration, including challenges in the methods for fabricating small, densely-packed structures (e.g., conductive structures, such as access lines (e.g., word lines)) of the electronic devices. Meeting those design and fabrication challenges without sacrificing electronic device performance is a particularly difficult challenge. For example, electronic devices configured as memory devices often need to exhibit sufficient performance characteristics, such as low electrical resistivity (e.g., high electrical conductivity) and low so-called “row hammer” characteristic (e.g., a measure of a memory cell's tendency to leak charge, such as via junction leakage and/or gate-induced drain leakage (GIDL), and interact electrically with a neighbor, unintentionally, which can lead to possibly changing the charge and storage of the leaking cell as well as the impacted neighboring cells of the memory device).
As an example, conductive structures—such as conductive gates (e.g., gate electrodes) of access lines (e.g., word lines) of microelectronic device structures—may be frequently operated, during operation of the microelectronic device(s), to enable frequent accessing of a row of devices (e.g., memory devices). In conventional word line metal gate structures, formed in accordance with conventional fabrication methods, the frequent operation of word line metal gates tend to cause row hammer characteristics—e.g., the introduction of parasitic coupling with adjacent, non-accessed rows of devices. Such row hammer characteristics can cause adjacent rows to interact in an undesired way to cause memory cells to unintentionally flip from one state to another state, causing errors in memory storage and reading in a “victim” row. However, with these or other conductive structures of microelectronic devices, optimizing one performance parameter of an electronic device often detrimentally impacts another performance parameter of that device. For example, conductive materials (e.g., titanium nitride (TiN)) that generally exhibit low electrical resistivity may tend to negatively impact an exhibited row hammer characteristic, at least if the material is formed according to conventional methods.
Designing and fabricating electronic devices (e.g., memory devices) and materials and structures thereof (e.g., materials and structures comprising TiN) in a manner that enables the electronic device to exhibit sufficiently low conductivity with good row hammer performance continues to present challenges.
Structures (e.g., microelectronic device structures), apparatus (e.g., microelectronic devices), and systems (e.g., electronic systems), according to embodiments of the disclosure, include at least one structure formed of and including titanium nitride (TiN). The TiN structures may be configured as, e.g., a conductive structure of a microelectronic device (e.g., a memory device, such as a DRAM device). For example, and without limitation, the TiN structures may be configured as a conductive electrode, a conductive gate, a conductive access line (e.g., a conductive “word line”), or other conductive structure of the microelectronic device. The TiN structure is formed through a process (e.g., an atomic layer deposition (“ALD”) process, a chemical vapor deposition (“CVD”) process, an ALD-like CVD process, a furnace process) using a reducing gas (“RG”) introduced in conjunction with introduction of a titanium-including gas (e.g., TiCl4). A nitrogen-including gas (e.g., ammonia NH3) is not concurrently flowed with either the titanium-including gas (e.g., TiCl4) or the reducing gas RG. Also, the nitrogen-including gas (e.g., ammonia NH3) is not flowed in between flow of the titanium-including gas (e.g., TiCl4) and the reducing gas RG.
By these methods, the TiN material is formed in substantially continuous layers (e.g., films), exhibiting few or no void spaces (e.g., gaps, seams) between grains of TiN material. Therefore, the resulting TiN structures exhibit not only the low electrical resistivity (e.g., high conductivity) of TiN material, but also exhibit low row hammer characteristics, with minimal or no current leakage. Moreover, the methods of embodiments of the disclosure inhibit species (e.g., one or more halides, such as chlorine (Cl), from the reaction gases of the material-formation process) from diffusing and forming trap sites or other defects at interfaces with other materials (e.g., gate oxide material). Accordingly, the TiN material—and TiN structures—formed in accordance with embodiments of the disclosure may be conducive for forming word line metal gates of microelectronic device structures (e.g., memory devices, such as DRAM devices), namely word line metal gates.
As used herein, the term “memory device” means and includes a microelectronic device exhibiting memory functionality, but not necessarily limited to memory functionality. In other words, and by way of example only, the term “memory device” means and includes not only conventional memory (e.g., conventional volatile memory, such as conventional dynamic random access memory (DRAM); conventional non-volatile memory, such as conventional NAND memory), but also includes an application specific integrated circuit (ASIC) (e.g., a system on a chip (SoC)), a microelectronic device combining logic and memory, and a graphics processing unit (GPU) incorporating memory.
As used herein, the term “reducing gas” means and includes a gas formulated as a reducing agent, i.e., gas including an element or compound formulated to lose (or “donate”) an electron to an electron recipient in a redox chemical reaction.
As used herein, the terms “introduce” and “introducing,” when used with respect to a gas or gases, mean and include an initial exposure of a structure or material—on which another structure or material is being formed—to such gas(es). A gas (or gases) may be “introduced” by causing the gas(es) to flow into an environment (e.g., a chamber) containing the structure or material on which the other structure or material is to be formed. Thus, the structure or material—on which another structure or material is being formed—is first exposed to the gas(es) by “introducing” the gas(es).
As used herein, the terms “flow” and “flowing,” when used with respect to a gas or gases, mean an include an initial or continued exposure of a structure or material—on which another structure material is or has been formed—to such gas(es). A gas (or gases) may be “flowed” by causing the gas(es) to pass over (e.g., “flow across”) the structure or material—on which the another structure or material is or has been formed—or by causing the gas(es) to otherwise come into sufficient contact with the structure or material—on which the another structure or material is or has been formed—so as to deposit at least one species from the gas(es) onto the other structure or material. Thus, the structure or material—on which another structure or material is being formed or has been formed—is exposed to the gas(es) by “flowing” the gas(es) over or onto the structure or material.
As used herein, the term “species” means and includes an element or elements (e.g., molecule(s), chemical group(s)) composing or derived from a material or composition. As nonlimiting examples, in a composition comprising SiH4, each of silicon (Si) and hydrogen (H) may be referred to herein as a “species” of the SiH4; and in a composition comprising TiCl4, each of Ti and chlorine (Cl) may be referred to herein as a “species” of the TiCl4, regardless of whether such species are, at the time of reference, presently within the originating material or composition or, instead, within or on another material or composition.
As used herein, the term “trace species” means and includes an element or elements, such as atoms or molecules, derived from one material or composition to be present on or within a volume of another material(s) in a trace amount, e.g., an atomic fraction (atoms of the treatment species relative to atoms of other species within the other material(s)) of from about 1×10−8 to about 1×10−1, e.g., from about (0.001 to about 0.01). The trace amount may be determined based on a total volume of material(s) of an identified characteristic (e.g., material(s)) of a structure or region (e.g., a discrete region) of the structure, though the treatment species may be, e.g., concentrated at or near a surface of the material(s), concentrated at or near an interface between portions of the material(s), and/or dispersed throughout the volume (e.g., of the structure or the region of the structure).
As used herein, the term “trap site” means and refers to at least one of an under-coordinated, frustrated, or dangling bond or point defect of an atom or structure of the material comprising the trap site. For example, and without limitation, a “trap site” includes an unsatisfied valence on an atom. Due to the unsatisfied coordination or valency, the trap site may be highly reactive, and, in case of covalent bonding, the unpaired electrons of the dangling bond may react with electrons in other atoms in order to fill the valence shell of the atom. The atom with a trap site may be a free radical in an immobilized material, e.g., a solid.
As used herein, the term “opening” means a volume extending through at least one structure or at least one material, leaving a gap in that at least one structure or at least one material, or a volume extending between structures or materials, leaving a gap between the structures or materials. Unless otherwise described, an “opening” is not necessarily empty of material. That is, an “opening” is not necessarily void space. An “opening” formed in or between structures or materials may comprise structure(s) or material(s) other than that in or between which the opening or slit is formed. And, structure(s) or material(s) “exposed” within an opening or slit is (are) not necessarily in contact with an atmosphere or non-solid environment. Structure(s) or material(s) “exposed” within an opening may be adjacent or in contact with other structure(s) or material(s) that is (are) disposed within the opening.
As used herein, the term “substrate” means and includes a base material, base structure, or other construction upon which components, such as those within memory cells, are formed. The substrate may be a semiconductor substrate, a base semiconductor material on a supporting structure, a metal electrode, or a semiconductor substrate having one or more materials, structures, or regions formed thereon. The substrate may be a conventional silicon substrate or other bulk substrate including a semiconductive material. As used herein, the term “bulk substrate” means and includes not only silicon wafers, but also silicon-on-insulator (“SOI”) substrates, such as silicon-on-sapphire (“SOS”) substrates or silicon-on-glass (“SOG”) substrates, epitaxial layers of silicon on a base semiconductor foundation, or other semiconductor or optoelectronic materials, such as silicon-germanium (Si1-xGex, where x is, for example, a mole fraction between 0.2 and 0.8), germanium (Ge), gallium arsenide (GaAs), gallium nitride (GaN), or indium phosphide (InP), among others. Furthermore, when reference is made to a “substrate” in the following description, previous process stages may have been utilized to form materials, structures, or junctions in the base semiconductor structure or foundation.
As used herein, the term “sacrificial,” when referring to a material or structure, means and includes a material or structure that is formed during a fabrication process but which is removed prior to completion of the fabrication process.
As used herein, the terms “horizontal” or “lateral” mean and include a direction that is parallel to a primary surface of the substrate on which the referenced material or structure is located. The width and length of a respective material or structure may be defined as dimensions in a horizontal plane. With reference to the figures, the “horizontal” direction may be perpendicular to an indicated “Z” axis and may be parallel to an indicated “X” axis and/or parallel to an indicated “Y” axis.
As used herein, the terms “vertical” or “longitudinal” mean and include a direction that is perpendicular to a primary surface of the substrate on which a referenced material or structure is located. The height of a respective material or structure may be defined as a dimension in a vertical plane. With reference to the figures, the “vertical” direction may be parallel to an indicated “Z” axis, may be perpendicular to an indicated “X” axis, and may be perpendicular to an indicated “Y” axis.
As used herein, the terms “thickness” and “thinness” mean and include a dimension in a straight-line direction that is normal to the closest surface of an immediately adjacent material or structure that is of a different composition or that is otherwise distinguishable from the material or structure whose thickness or thinness is discussed.
As used herein, the term “between” is a spatially relative term used to describe the relative disposition of one material, structure, or sub-structure relative to at least two other materials, structures, or sub-structures. The term “between” may encompass both a disposition of one material, structure, or sub-structure directly adjacent the other materials, structures, or sub-structures and a disposition of one material, structure, or sub-structure indirectly adjacent to the other materials, structures, or sub-structures.
As used herein, the term “proximate” is a spatially relative term used to describe disposition of one material, structure, or sub-structure near to another material, structure, or sub-structure. The term “proximate” includes dispositions of indirectly adjacent to, directly adjacent to, and internal to.
As used herein, the term “neighboring,” when referring to a material or structure, means and refers to a next, most proximate material or structure of an identified composition or characteristic. Materials or structures of other compositions or characteristics than the identified composition or characteristic may be disposed between one material or structure and its “neighboring” material or structure of the identified composition or characteristic. For example, a structure of material X “neighboring” a structure of material Y is the first material X structure, e.g., of multiple material X structures, that is next most proximate to the particular structure of material Y. The “neighboring” material or structure may be directly or indirectly proximate the structure or material of the identified composition or characteristic.
As used herein, the term “consistent”—when referring to a parameter, property, or condition of one structure, material, or feature in comparison to the parameter, property, or condition of another such structure, material, or feature—means and includes the parameter, property, or condition of the two such structures, materials, or features being equal, substantially equal, or about equal, at least in terms of respective portions of such structures, materials, or features. For example, two structures having “consistent” thicknesses as one another may each define a same, substantially same, or about the same thickness at X lateral distance from a feature, despite the two structures being at different elevations along the feature.
As used herein, the terms “about” and “approximately,” when either is used in reference to a numerical value for a particular parameter, are inclusive of the numerical value and a degree of variance from the numerical value that one of ordinary skill in the art would understand is within acceptable tolerances for the particular parameter. For example, “about” or “approximately,” in reference to a numerical value, may include additional numerical values within a range of from 90.0 percent to 110.0 percent of the numerical value, such as within a range of from 95.0 percent to 105.0 percent of the numerical value, within a range of from 97.5 percent to 102.5 percent of the numerical value, within a range of from 99.0 percent to 101.0 percent of the numerical value, within a range of from 99.5 percent to 100.5 percent of the numerical value, or within a range of from 99.9 percent to 100.1 percent of the numerical value.
As used herein, the term “substantially,” when referring to a parameter, property, or condition, means and includes the parameter, property, or condition being equal to or within a degree of variance from a given value such that one of ordinary skill in the art would understand such given value to be acceptably met, such as within acceptable manufacturing tolerances. By way of example, depending on the particular parameter, property, or condition that is substantially met, the parameter, property, or condition may be “substantially” a given value when the value is at least 90.0% met, at least 95.0% met, at least 99.0% met, or even at least 99.9% met.
As used herein, reference to an element as being “on” or “over” another element means and includes the element being directly on top of, adjacent to (e.g., laterally adjacent to, vertically adjacent to), underneath, or in direct contact with the other element. It also includes the element being indirectly on top of, adjacent to (e.g., laterally adjacent to, vertically adjacent to), underneath, or near the other element, with other elements present therebetween. In contrast, when an element is referred to as being “directly on” or “directly adjacent to” another element, there are no intervening elements present.
As used herein, other spatially relative terms, such as “below,” “lower,” “bottom,” “above,” “upper,” “top,” and the like, may be used for ease of description to describe one element's or feature's relationship to another element(s) or feature(s) as illustrated in the figures. Unless otherwise specified, the spatially relative terms are intended to encompass different orientations of the materials in addition to the orientation as depicted in the figures. For example, if materials in the figures are inverted, elements described as “below” or “under” or “on bottom of” other elements or features would then be oriented “above” or “on top of” the other elements or features. Thus, the term “below” may encompass both an orientation of above and below, depending on the context in which the term is used, which will be evident to one of ordinary skill in the art. The materials may be otherwise oriented (rotated ninety degrees, inverted, etc.) and the spatially relative descriptors used herein interpreted accordingly.
As used herein, the terms “comprising,” “including,” “having,” and grammatical equivalents thereof are inclusive or open-ended terms that do not exclude additional, unrecited elements or method steps, but these terms also include more restrictive terms “consisting of” and “consisting essentially of” and grammatical equivalents thereof. Therefore, a structure described as “comprising,” “including,” and/or “having” a material may be a structure that, in some embodiments, includes additional material(s) as well and/or a structure that, in some embodiments, does not include any other material(s). Likewise, a composition (e.g., gas) described as “comprising,” “including,” and/or “having” a species may be a composition that, in some embodiments, includes additional species as well and/or a composition that, in some embodiments, does not include any other species.
As used herein, the term “in conjunction with,” when used with respect to two or more processing stages, acts, or compositions thereof, means and refers to the processing stages, acts, or compositions being carried out, performed, or utilized in close time proximity with one another or concurrently. For example, a first composition gas introduced “in conjunction with” a second composition gas means and includes the first composition gas being introduced immediately before, during, or immediately after the second composition gas, e.g., without an intervening purge. Furthermore, as used herein, the term “in conjunction with” is an inclusive or open-ended term that does not exclude additional, unrecited processing stages, acts, or compositions thereof. Such term also includes a more restrictive term of “in conjunction with only,” which indicates an exclusion of additional, unrecited processing stages, acts, or compositions thereof.
As used herein, the term “may” with respect to a material, structure, feature, or method act indicates that such is contemplated for use in implementation of an embodiment of the disclosure and such term is used in preference to the more restrictive term “is” so as to avoid any implication that other, compatible materials, structures, features, and methods usable in combination therewith should or must be excluded.
As used herein, “and/or” includes any and all combinations of one or more of the associated listed items.
As used herein, the singular forms “a,” “an,” and “the” are intended to include the plural forms as well, unless the context clearly indicates otherwise.
As used herein, the terms “configured” and “configuration” mean and refer to a size, shape, material composition, orientation, and arrangement of a referenced material, structure, assembly, or apparatus so as to facilitate a referenced operation or property of the referenced material, structure, assembly, or apparatus in a predetermined way.
The illustrations presented herein are not meant to be actual views of any particular material, structure, sub-structure, region, sub-region, device, system, or stage of fabrication, but are merely idealized representations that are employed to describe embodiments of the disclosure.
Embodiments are described herein with reference to cross-sectional illustrations that are schematic illustrations. Accordingly, variations from the shapes of the illustrations as a result, for example, of manufacturing techniques and/or tolerances, are to be expected. Thus, embodiments described herein are not to be construed as limited to the particular shapes or structures as illustrated but may include deviations in shapes that result, for example, from manufacturing techniques. For example, a structure illustrated or described as box-shaped may have rough and/or nonlinear features. Moreover, sharp angles that are illustrated may be rounded. Thus, the materials, features, and structures illustrated in the figures are schematic in nature and their shapes are not intended to illustrate the precise shape of a material, feature, or structure and do not limit the scope of the present claims.
The following description provides specific details, such as material types and processing conditions, in order to provide a thorough description of embodiments of the disclosed apparatus (e.g., devices, systems) and methods. However, a person of ordinary skill in the art will understand that the embodiments of the apparatus and methods may be practiced without employing these specific details. Indeed, the embodiments of the apparatus and methods may be practiced in conjunction with conventional semiconductor fabrication techniques employed in the industry.
The fabrication processes described herein do not form a complete process flow for processing apparatus (e.g., devices, systems) or the structures thereof. The remainder of the process flow is known to those of ordinary skill in the art. Accordingly, only the methods and structures necessary to understand embodiments of the present apparatus (e.g., devices, systems) and methods are described herein.
Unless the context indicates otherwise, the materials described herein may be formed by any suitable technique including, but not limited to, spin coating, blanket coating, chemical vapor deposition (“CVD”), atomic layer deposition (“ALD”), plasma enhanced ALD, physical vapor deposition (“PVD”) (e.g., sputtering), or epitaxial growth. Depending on the specific material to be formed, the technique for depositing or growing the material may be selected by a person of ordinary skill in the art.
Unless the context indicates otherwise, the removal of materials described herein may be accomplished by any suitable technique including, but not limited to, etching (e.g., dry etching, wet etching, vapor etching), ion milling, abrasive planarization, or other known methods.
In referring to the drawings, like numerals refer to like components throughout. The drawings are not necessarily drawn to scale.
Methods of forming microelectronic device structures, of a microelectronic devices (e.g., a memory device, such as a DRAM device)—that include titanium nitride (TiN) material and structures—include forming the TiN material and structures according to a material-formation method in which a titanium-including gas (e.g., TiCl4) is introduced in conjunction with a reducing gas RG (e.g., a silicon-based gas) after and/or before a nitrogen-based gas (e.g., NH3) is introduced. Unexpectedly, such a method forms TiN in substantially continuous layers (e.g, monolayers, films), enabling a TiN structure to be formed—with successively formed TiN layers—with minimal or no void spaces that may otherwise enable current leakage (e.g., row hammer characteristics). Moreover, the TiN may be formed in a manner that species from the introduced gases do not diffuse out of the material being formed to cause trap sites that may detrimentally impact neighboring structures. Still further, the TiN material and structures, formed according to embodiments of the disclosure, may include trace species from the reducing gas, which trace species may inhibit grain growth and swelling of the TiN material during subsequent thermal processing acts.
For example,
With a precursor structure (e.g., a structure upon which a TiN material is to be formed) within the chamber, the method 100 may, optionally, include first exposing the precursor structure to a nitrogen-including gas (e.g., NH3) (stage 102), which deposits nitrogen on an exposed surface of the structure. In embodiments in which the nitrogen-including gas (e.g., NH3) is a first composition introduced to the precursor structure within a chamber (e.g., at stage 102), a purge (stage 104) is performed to substantially rid the chamber(s) of the nitrogen-including gas (e.g., NH3).
In some embodiments, rather than beginning with introduction of the nitrogen-including gas (e.g., the NH3) (stage 102) and the purge (stage 104)—or as a next stage subsequent to those stages—a titanium-including gas (e.g., TiCl4) is first—or next—introduced in conjunction with introduction of a reducing gas RG (stage 106). The titanium-including gas of stage 106 (and of other stages utilizing a titanium-including gas) may be or include a titanium halide gas (e.g., TiCl4), wherein the titanium (Ti) is accompanied by (e.g., bonded to) a halogen (e.g., chlorine (Cl)). The reducing gas RG of stage 106 (and of other stages utilizing a reducing gas RG) may be or include a silicon-based gas (e.g., a silane gas, such as SiH4, disilane (Si2H6), trisilylamine (N(SiH3)3), trisilane (Si3H3)3, an organo-silane (e.g., t-amyl silylene)). In some embodiments, the reducing gas RG of stage 106 (and of other stages utilizing a reducing gas RG) may further comprise hydrogen gas (H2). With respect to the aforementioned t-amyl silylene, it may have the following chemical structure:
The introduction and flow of the titanium-including gas (e.g., TiCl4) in conjunction with the reducing gas RG may not be in conjunction with introduction or flow of a nitrogen-including gas (e.g., NH3). That is, the chamber may be free or substantially free of any nitrogen-including gas (e.g., NH3) from the first introduction of one of the titanium-including gas (e.g., TiCl4) or the reducing gas RG until the last stoppage of flow of the titanium-including gas (e.g., TiCl4) and the reducing gas RG.
Exposing the precursor structure—whether already including or not yet including nitrogen atoms on a surface thereof—deposits titanium (Ti) atoms on the exposed surface(s). The concurrent or subsequent presence of the reducing gas RG (e.g., silicon-based gas) may inhibit deposition of one or more halogen-including species, such as chlorine-including species, from the titanium-including gas. Alternatively or additionally, the concurrent or subsequent presence of the reducing gas RG may promote removal (e.g., desorption) of halogen-including species from the surface(s) on which the titanium is being formed. For example, the concurrent or subsequent presence of the reducing gas RG may inhibit halogen-including compounds (e.g., HCl) from forming in the TiN material being formed and/or may promote desorption of halogen-including compounds (e.g., HCl) from the TiN material being formed.
In some embodiments, the TiN material formed may be substantially free of halogen species. For example, the TiN material may comprise less than about 0.05 at. % halogen species (e.g., about 0.04 at. % halogen species (such as about 0.04 at. % Cl), or less), as measured by, e.g., secondary-ion mass spectrometry (SIMS). The substantial absence of the halogen species may inhibit formation of voids or seams between grains of the TiN material in the resulting structure, enabling each layer (e.g., monolayer, film) of the TiN material to be formed substantially continuously. Unexpectedly, the substantially continuous layers are enabled despite the exposure of structures to the reducing gas (e.g., silicon-based gas), which may result in trace species from the reducing gas being formed in the TiN material. For example, trace amounts (e.g., less than about 1 at. %) of silicon (Si) may be included the TiN material. Even so, the TiN material may be formed substantially continuously, avoiding voids and seams that may otherwise lead to current leakage. Thus, the formed TiN material and structures may exhibit good (e.g., low) row hammer characteristics while also exhibiting low electrical resistivity as TiN material. Moreover, the substantial absence of halogen species (e.g., less than about 0.05 at. % halogen species, e.g., less than about 0.05 at. % chlorine (Cl), as measured by, e.g., SIMS) in the TiN material and structures formed may avoid such halogen species from subsequently diffusing into neighboring materials or structures to cause trap sites or other defects therein. This may further improve the performance properties of the TiN material and structures formed.
Introducing the titanium-including gas (e.g., TiCl4) in conjunction with the reducing gas RG (stage 106) may include, in some embodiments, introducing the titanium-including gas first and continuing flow of the titanium-including gas while concurrently introducing the reducing gas RG, and/or may include, in some embodiments, introducing the titanium-including gas first followed by flow of the titanium-including gas. For example, stage 106 of
According to the stage 106′ of
According to the stage 106″ of
According to the stage 106′″ of
In these or other embodiments, the illustrated lines between start points and stop points (e.g., between flow start point 118 and flow stop point 120, between flow start point 122 and flow stop point 124) may be continuous without breaks in the flow of the respective gas, or may be segmented into more than one start-and-stop period of gas flow, with or without an intervening purge. Nonetheless, the introduction and/or flow of the titanium-including gas (e.g., TiCl4) is in conjunction with the introduction and/or flow of the reducing gas RG, and these introductions and flows are not in conjunction with introduction or flow of a nitrogen-including gas (e.g., NH3). In some embodiments, a purge may be performed in between a stage that includes flow of nitrogen-including gas (e.g., NH3) and a stage that includes flow of either or both of the titanium-including gas (e.g., TiCl4) and/or the reducing gas RG, to ensure that the chamber(s) is(are) substantially free of gas-form nitrogen during the exposure of a structure to the titanium-including gas and the reducing gas RG.
After the exposure of the structure to the titanium-including gas (e.g., TiCl4) in conjunction with the reducing gas RG (stage 106 of
The resulting TiN material may be substantially continuously formed on an underlying structure (e.g., a gate oxide material), such as with substantially continuous monolayers of titanium interleaved with substantially continuous monolayers of nitrogen, with only trace amounts of species (e.g., silicon (Si)) from the reducing gas RG. As discussed further below, the TiN material may form grains with few voids, seams, or other empty interstitial space between grains of the TiN, due to formation of the material by methods in accordance with embodiments of the disclosure. As discussed above, the substantial continuity of the material formed may be enabled by the reducing gas RG effectively preventing deposition of, or promoting desorption of, halogen-including species (e.g., HCl) in or on the deposited titanium and nitrogen material, unexpectedly even as trace amounts of species (e.g., silicon Si) from the reducing gas RG may also form in the TiN material. The absence of halogen-including species in the deposited TiN material also inhibits such halogen-including species from subsequently diffusing out of the TiN material and causing trap sites or other defects in neighboring materials or structures.
In some embodiments, after forming the TiN material (e.g., by stage 106 through stage 112 (and/or stage 114) in repetition, either with or without being preceded by stage 102 and stage 104), a cap may be formed on an exposed (e.g., upper) surface of the TiN material, as indicated at stage 116 of
In some embodiments, the formation of the cap (stage 116 of
In other embodiments, the formation of the cap (stage 116 of
Accordingly, disclosed is a method of forming a microelectronic device. The method comprises forming a titanium nitride (TiN) material over a precursor structure. Forming the TiN material comprises repeating cycles that comprise flowing a titanium-including gas adjacent the precursor structure; flowing a reducing gas over the precursor structure; flowing a nitrogen-including gas over the precursor structure; and, before and after flowing the nitrogen-including gas, purging gas.
The methods discussed above may be used to form a TiN material and structure of a microelectronic device (e.g., a memory device, such as a DRAM device), such as an access line gate (e.g., a word line gate). For example,
With reference to
With reference to
In some embodiments, all of the TiN material 210 may be formed by embodiments of the disclosure (e.g., the method 100 of
By forming the TiN material 210, in whole or at least in first part, by embodiments of the disclosure (e.g., the method 100 of
With reference to
In some embodiments, the cap-formation stage (e.g., stage 116 of
In other embodiments, the cap structure may be formed according to the stage 116″ of
Accordingly, the cap structure (e.g., the monolayer cap structure 214 of
After forming the cap structure (e.g., the monolayer cap structure 214 of
With reference to
With reference to
In some embodiments, the fins 302 illustrated in
An uppermost portion of the fins 302 (and the liner 304, if present) may be significantly curved, tapering toward a dull point, or gradually curving along the uppermost portion of a surface of the fins 302. A TiN material (e.g., the TiN material 210 of
In some embodiments, subsequent to forming the TiN material by the material-formation process described above, a thermal processing stage may be performed. In the thermal processing stage, the material of the TiN structure 314 may be subjected to a temperature exceeding about 300° C. (e.g., temperature(s) between about 300° C. to about 500° C., such as if the reducing gas RG comprises silane gas; or temperatures greater than about 500° C., such as if the reducing gas RG comprises disilane gas). The exposure to the increased heat may lead to some grain growth, e.g., merging of grains 308 (
In comparison, a TiN material formed according to a conventional deposition process may result in a structure with relatively larger grains of TiN material and a greater quantity of voids in interstitial spaces between the larger grains. The larger grains may be the result of significant grain growth and/or swelling during thermal processing stages, which significant grain growth and/or swelling may be avoided or lessened according to embodiments of the disclosure. For example, the grains 308 (
In addition to the method 100 (
Moreover, while a TiN material formed according to conventional methods may include voids that allow for current leakage and higher row hammer characteristics, the TiN material and the TiN structure 314 of the microelectronic device structure 316 of
In some embodiments, the microelectronic device structure 316 of
Accordingly, disclosed is a microelectronic device. The microelectronic device comprises a conductive structure recessed within a base structure. The conductive structure comprises titanium nitride and less than about five atomic percent silicon throughout at least a portion of the titanium nitride. A dielectric liner is between the conductive structure and the base structure.
In some embodiments, the structures (e.g., conductive structures) formed of the TiN material, according to embodiments of the disclosure, may be substantially free of other conductive materials, such as being substantially free of one or more of tungsten (W), ruthenium (Ru), copper (Cu), tantalum (Ta), cobalt (Co), or molybdenum (Mo). Even so, the TiN materials and structures, formed according to the method 100 of
Electronic devices (e.g., semiconductor devices, memory devices (e.g., DRAM devices)) formed by methods of embodiments herein and/or including structures (e.g., microelectronic device structure 224 (
The electronic system 400 may further include one or more input devices 406 for inputting information into the electronic system 400 by a user, e.g., a pointing device (e.g., a mouse), a keyboard, a touchpad, a button, a control panel, or combinations thereof. The electronic system 400 may further include one or more output devices 408 for outputting information (e.g., visual output, audio output) to a user, e.g., a monitor, a display, a printer, an audio output jack, a speaker, etc. In some embodiments, the input device 406 and the output device 408 may comprise a device configured for both input and output (e.g., a touch screen device) that can be used both to input information into the electronic system 400 and to output visual information to a user. The one or more input devices 406 and output devices 408 may communicate electrically with at least one of the memory device 402 and the processor device 404.
Accordingly, disclosed is an electronic system. The electronic system comprises an input device, an output device, a processor device, and a memory device. The processor device is operably coupled to the input device and to the output device. The memory device is operably coupled to the processor device. The memory device comprises at least one microelectronic device structure. The at least one microelectronic device structure comprises at least one access line gate structure. The at least one access line gate structure comprises titanium nitride and a silicon species dispersed throughout the titanium nitride. The silicon species constitutes less than about five atomic percent of the titanium nitride.
While the disclosed devices, structures, and methods are susceptible to various modifications and alternative forms in implementation thereof, specific embodiments have been shown by way of example in the drawings and have been described in detail herein. However, the disclosure is not intended to be limited to the particular forms disclosed. Rather, the disclosure encompasses all modifications, combinations, equivalents, variations, and alternatives falling within the scope of the disclosure as defined by the following appended claims and their legal equivalents.