Conductive line construction, memory circuitry, and method of forming a conductive line construction
11075274 · 2021-07-27
Assignee
Inventors
Cpc classification
H01L21/28052
ELECTRICITY
H01L29/4941
ELECTRICITY
H01L29/42372
ELECTRICITY
International classification
H01L29/49
ELECTRICITY
H01L21/28
ELECTRICITY
Abstract
A method of forming a conductive line construction comprises forming a structure comprising polysilicon-comprising material. Elemental titanium is directly against the polysilicon of the polysilicon-comprising material. Silicon nitride is directly against the elemental titanium. Elemental tungsten is directly against the silicon nitride. The structure is annealed to form a conductive line construction comprising the polysilicon-comprising material, titanium silicide directly against the polysilicon-comprising material, elemental tungsten, TiSi.sub.xN.sub.y between the elemental tungsten and the titanium silicide, and one of (a) or (b), with (a) being the TiSi.sub.xN.sub.y is directly against the titanium silicide, and (b) being titanium nitride is between the TiSi.sub.xN.sub.y and the titanium silicide, with the TiSi.sub.xN.sub.y being directly against the titanium nitride and the titanium nitride being directly against the titanium silicide. Structure independent of method is disclosed.
Claims
1. A method of forming a conductive line construction, comprising: forming a structure comprising polysilicon-comprising material, elemental titanium directly against the polysilicon of the polysilicon-comprising material, silicon nitride directly against the elemental titanium, and elemental tungsten directly against the silicon nitride; and annealing the structure to form a conductive line construction comprising: the polysilicon-comprising material; titanium silicide directly against the polysilicon-comprising material; elemental tungsten; TiSi.sub.xN.sub.y between the elemental tungsten and the titanium silicide; and one of (a) or (b), where, (a): the TiSi.sub.xN.sub.y is directly against the titanium silicide; (b): titanium nitride is between the TiSi.sub.xN.sub.y and the titanium silicide, the TiSi.sub.xN.sub.y being directly against the titanium nitride, the titanium nitride being directly against the titanium silicide.
2. The method of claim 1 comprising forming the silicon nitride to be amorphous.
3. The method of claim 1 comprising forming all of the silicon nitride at a temperature of no greater than 350° C.
4. The method of claim 1 comprising: forming the polysilicon-comprising material, the elemental titanium, the silicon nitride, and the elemental tungsten over a substrate; and forming each of the elemental titanium, the silicon nitride, and the elemental tungsten over the substrate in sub-atmospheric conditions; the substrate being kept at sub-atmospheric conditions at all times between forming all of the elemental titanium and forming all of the elemental tungsten.
5. The method of claim 4 comprising forming the silicon nitride by physical vapor deposition at a temperature of no greater than 350° C.
6. The method of claim 1 wherein the annealing comprises a temperature of at least 800° C.
7. The method of claim 1 comprising forming the elemental titanium to a thickness of 15 Angstroms to 30 Angstroms.
8. The method of claim 1 comprising forming the silicon nitride to a thickness of 25 Angstroms to 40 Angstroms and forming the TiSi.sub.xN.sub.y to a thickness of 20 Angstroms to 70 Angstroms.
9. The method of claim 1 wherein the annealing forms the TiSi.sub.xN.sub.y directly against the elemental tungsten.
10. The method of claim 1 wherein the annealing leaves the silicon nitride at a thickness of no more than 10 Angstroms between the TiSi.sub.xN.sub.y and the elemental tungsten, the TiSi.sub.xN.sub.y being directly against the silicon nitride of thickness of no more than 10 Angstroms, the elemental tungsten being directly against the silicon nitride of thickness of no more than 10 Angstroms.
11. The method of claim 1 being (a).
12. The method of claim 11 only being the (a) of the (a) and the (b).
13. The method of claim 1 being (b).
14. The method of claim 13 only being the (b) of the (a) and the (b).
15. A method comprising: forming a structure comprising polysilicon-comprising material, titanium-comprising material over the polysilicon-comprising material, material consisting essentially of silicon nitride over the titanium-comprising material, and tungsten-comprising material over the material consisting essentially of silicon nitride; and annealing the structure to cause at least a part of the silicon nitride to be converted into conductive material comprising titanium, silicon and nitrogen.
16. A conductive line construction comprising: polysilicon-comprising material; a metal silicide directly against the polysilicon of the polysilicon-comprising material; elemental tungsten; TiSi.sub.xN.sub.y between the elemental tungsten and the metal silicide; and titanium nitride being between the TiSi.sub.xN.sub.y and the metal silicide, the TiSi.sub.xN.sub.y being directly against the titanium nitride, the titanium nitride being directly against the metal silicide.
17. A method comprising: forming a structure comprising polysilicon-comprising material, titanium-comprising material over the polysilicon-comprising material, silicon nitride-comprising material over the titanium-comprising material, and tungsten-comprising material over the silicon nitride-comprising material, the silicon nitride-comprising material being in the structure as amorphous silicon nitride-comprising material; and annealing the structure to cause at least a part of the silicon nitride to be converted into conductive material comprising titanium, silicon and nitrogen.
18. A method comprising: forming a structure comprising polysilicon-comprising material, titanium-comprising material over the polysilicon-comprising material, silicon nitride-comprising material over the titanium-comprising material, and tungsten-comprising material over the silicon nitride-comprising material; the polysilicon-comprising material consists essentially of polysilicon, the titanium-comprising material consists essentially of elemental titanium, the silicon nitride-comprising material consists essentially of silicon nitride, and the tungsten-comprising material consists essentially of elemental tungsten; and annealing the structure to cause at least a part of the silicon nitride to be converted into conductive material comprising titanium, silicon and nitrogen.
19. A conductive line construction comprising: polysilicon-comprising material; a metal silicide directly against the polysilicon of the polysilicon-comprising material; elemental tungsten; TiSi.sub.xN.sub.y between the elemental tungsten and the metal silicide; titanium nitride between the TiSi.sub.xN.sub.y and the metal silicide, the TiSi.sub.xN.sub.y being directly against the titanium nitride, the titanium nitride being directly against the metal silicide; and silicon nitride between the TiSi.sub.xN.sub.y and the elemental tungsten, the silicon nitride being no thicker than 10 Angstroms, the elemental tungsten being directly against the silicon nitride, and the silicon nitride being directly against the TiSi.sub.xN.sub.y.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
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DETAILED DESCRIPTION OF EXAMPLE EMBODIMENTS
(12) Embodiments of the invention encompass methods of forming a conductive line construction as well as a conductive line construction independent of method of manufacture. Embodiments of the invention also encompass memory circuitry. First example embodiments are described with reference to
(13) Referring to
(14) Example structure 12 is shown as a vertical stack of several materials that have been collectively patterned relative to substrate 11, for example to form a longitudinally-elongated horizontal line running into and out of the plane of page upon which
(15) In one embodiment, each of elemental titanium 16, silicon nitride 18, and elemental tungsten 20 is formed over substrate 11/14 in sub-atmospheric conditions (e.g., below 100 mTorr), with the substrate being kept at sub-atmospheric conditions at all times between forming all of elemental titanium 16 and forming all of elemental tungsten 20. Such may occur, for example, by physical vapor deposition of one or more of materials 14, 16, 18, and 20 in one or more chambers where the substrate is kept under vacuum and not exposed to atmospheric conditions in movement from one chamber to another. By such physical vapor deposition, silicon nitride 18 may be formed as amorphous silicon nitride. In some examples, materials 14, 16, 18 and 20 may be used as a gate electrode of a transistor, and that may be formed on gate dielectric material (not shown) that is above substrate 11.
(16) Referring to
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(18) An alternate example embodiment conductive line construction 10b resulting from the annealing is shown and described with reference to
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(20) Alternate example methods of forming a conductive line construction are next described with reference to
(21) Referring to
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(23) An alternate example conductive line construction 10f is shown in
(24) An alternate example conductive line construction 10g is shown in
(25) Embodiments of the invention encompass structures and/or devices independent of method of manufacture. Nevertheless, such structures and/or devices may have any of the attributes as described herein in method embodiments. Likewise, the above-described method embodiments may incorporate and form any of the attributes described with respect to structures and/or devices embodiments.
(26) In one embodiment, a conductive line construction (e.g., 10, 10a, 10b, 10c, 10d, 10e, 10f, 10g) comprises polysilicon-comprising material (e.g., 14), a metal silicide (e.g., 22 and/or 32) directly against the polysilicon of the polysilicon-comprising material, elemental tungsten (e.g., 20), and TiSi.sub.xN.sub.y (e.g., 24) between the elemental tungsten and the metal silicide. The conductive line construction comprises one of (a) or (b), where (a): the TiSi.sub.xN.sub.y is directly against the metal silicide (e.g.,
(27) An embodiment of the invention comprises memory circuitry, for example circuitry 50 shown in
(28) The above processing(s) or construction(s) may be considered as being relative to an array of components formed as or within a single stack or single deck of such components above or as part of an underlying base substrate (albeit, the single stack/deck may have multiple tiers). Control and/or other peripheral circuitry for operating or accessing such components within an array may also be formed anywhere as part of the finished construction, and in some embodiments may be under the array (e.g., CMOS under-array). Regardless, one or more additional such stack(s)/deck(s) may be provided or fabricated above acid/or below that shown in the figures or described above. Further, the array(s) of components may be the same or different relative one another in different stacks/decks. Intervening structure may be provided between immediately-vertically-adjacent stacks/decks (e.g., additional circuitry and/or dielectric layers). Also, different stacks/decks may be electrically coupled relative one another. The multiple stacks/decks may be fabricated separately and sequentially (e.g., one atop another), or two or more stacks/decks may be fabricated at essentially the same time.
(29) The assemblies and structures discussed above may be used in integrated circuits/circuitry and may be incorporated into electronic systems. Such electronic systems may be used in, for example, memory modules, device drivers, power modules, communication modems, processor modules, and application-specific modules, and may include multilayer, multichip modules. The electronic systems may be any of a broad range of systems, such as, for example, cameras, wireless devices, displays, chip sets, set top boxes, games, lighting, vehicles, clocks, televisions, cell phones, personal computers, automobiles, industrial control systems, aircraft, etc.
(30) In this document unless otherwise indicated, “elevational”, “higher”, “upper”, “lower”, “top”, “atop”, “bottom”, “above”, “below”, “under”, “beneath”, “up”, and “down” are generally with reference to the vertical direction. “Horizontal” refers to a general direction (i.e., within 10 degrees) along a primary substrate surface and may be relative to which the substrate is processed during fabrication, and vertical is a direction generally orthogonal thereto. Reference to “exactly horizontal” is the direction along the primary substrate surface (i.e., no degrees there-from) and may be relative to which the substrate is processed during fabrication. Further, “vertical” and “horizontal” as used herein are generally perpendicular directions relative one another and independent of orientation of the substrate in three-dimensional space. Additionally, “elevationally-extending” and “extend(ing) elevationally” refer to a direction that is angled away by at least 45° from exactly horizontal. Further, “extend(ing) elevationally”, “elevationally-extending”, “extend(ing) horizontally”, “horizontally-extending” and the like with respect to a field effect transistor are with reference to orientation of the transistor's channel length along which current flows in operation between the source/drain regions. For bipolar junction transistors, “extend(ing) elevationally” “elevationally-extending”, “extend(ing) horizontally”, “horizontally-extending” and the like, are with reference to orientation of the base length along which current flows in operation between the emitter and collector. In some embodiments, any component, feature, and/or region that extends elevationally extends vertically or within 10° of vertical.
(31) Further, “directly above”, “directly below”, and “directly under” require at least some lateral overlap (i.e., horizontally) of two stated regions/materials/components relative one another. Also, use of “above” not preceded by “directly” only requires that some portion of the stated region/material/component that is above the other be elevationally outward of the other (i.e., independent of whether there is any lateral overlap of the two stated regions/materials/components). Analogously, use of “below” and “under” not preceded by “directly” only requires that some portion of the stated region/material/component that is below/under the other be elevationally inward of the other (i.e., independent of whether there is any lateral overlap of the two stated region s/materials/components).
(32) Any of the materials, regions, and structures described herein may be homogenous or non-homogenous, and regardless may be continuous or discontinuous over any material which such overlie. Where one or more example composition(s) is/are provided for any material, that material may comprise, consist essentially of, or consist of such one or more composition(s). Further, unless otherwise stated, each material may be formed using any suitable existing or future-developed technique, with atomic layer deposition, chemical vapor deposition, physical vapor deposition, epitaxial growth, diffusion doping, and ion implanting being examples.
(33) Additionally, “thickness” by itself (no preceding directional adjective) is defined as the mean straight-line distance through a given material or region perpendicularly from a closest surface of an immediately-adjacent material of different composition or of an immediately-adjacent region. Additionally, the various materials or regions described herein may be of substantially constant thickness or of variable thicknesses. If of variable thickness, thickness refers to average thickness unless otherwise indicated, and such material or region will have some minimum thickness and some maximum thickness due to the thickness being variable. As used herein, “different composition” only requires those portions of two stated materials or regions that may be directly against one another to be chemically and/or physically different, for example if such materials or regions are not homogenous. If the two stated materials or regions are not directly against one another, “different composition” only requires that those portions of the two stated materials or regions that are closest to one another be chemically and/or physically different if such materials or regions are not homogenous. In this document, a material, region, or structure is “directly against” another when there is at least some physical touching contact of the stated materials, regions, or structures relative one another. In contrast, “over”, “on”, “adjacent”, “along”, and “against” not preceded by “directly” encompass “directly against” as well as construction where intervening material(s), region(s), or structure(s) result(s) in no physical touching contact of the stated materials, regions, or structures relative one another.
(34) Herein, regions-materials-components are “electrically coupled” relative one another if in normal operation electric current is capable of continuously flowing from one to the other and does so predominately by movement of subatomic positive and/or negative charges when such are sufficiently generated. Another electronic component may be between and electrically coupled to the regions-materials-components. In contrast, when regions-materials-components are referred to as being “directly electrically coupled”, no intervening electronic component (e.g., no diode, transistor, resistor, transducer, switch, fuse, etc.) is between the directly electrically coupled regions-materials-components.
(35) The composition of any of the conductive/conductor/conducting materials herein may be metal material and/or conductively-doped semiconductive/semiconductor/semiconducting material. “Metal material” is any one or combination of an elemental metal, any mixture or alloy of two or more elemental metals, and any one or more conductive metal compound(s).
(36) Herein, “selective” as to etch, etching, removing, removal, depositing, forming, and/or formation is such an act of one stated material relative to another stated material(s) so acted upon at a rate of at least 2:1 by volume. Further, selectively depositing, selectively growing, or selectively forming is depositing, growing, or forming one material relative to another stated material or materials at a rate of at least 2:1 by volume for at least the first 75 Angstroms of depositing, growing, or forming.
(37) Unless otherwise indicated, use of “or” herein encompasses either and both.
CONCLUSION
(38) In some embodiments, a method of forming a conductive line construction comprises forming a structure comprising polysilicon-comprising material. Elemental titanium is directly against the polysilicon of the polysilicon-comprising material. Silicon nitride is directly against the elemental titanium. Elemental tungsten is directly against the silicon nitride. The structure is annealed to form a conductive line construction comprising the polysilicon-comprising material, titanium silicide directly against the polysilicon-comprising material, elemental tungsten, TiSi.sub.xN.sub.y between the elemental tungsten and the titanium silicide, and one of (a) or (b), with (a) being the TiSi.sub.xN.sub.y is directly against the titanium silicide, and (b) being titanium nitride is between the TiSi.sub.xN.sub.y and the titanium silicide, with the TiSi.sub.xN.sub.y being directly against the titanium nitride and the titanium nitride being directly against the titanium silicide.
(39) In some embodiments, a method of forming a conductive line construction comprises forming a structure comprising polysilicon-comprising material. Elemental metal is directly against the polysilicon of the polysilicon-comprising material. Elemental titanium is directly against the elemental metal. Silicon nitride is directly against the elemental titanium. Elemental tungsten is directly against the silicon nitride. The structure is annealed to form a conductive line construction comprising the polysilicon-comprising material, metal silicide directly against the polysilicon-comprising material, with the metal silicide comprising elemental metal that reacts with the polysilicon of the polysilicon-comprising material to form said metal silicide, elemental tungsten, TiSi.sub.xN.sub.y between the elemental tungsten and the metal silicide, and one of (a) or (b), with (a) being the TiSi.sub.xN.sub.y is directly against the metal silicide, and (b) being titanium nitride is between the TiSi.sub.xN.sub.y and the metal silicide, with the TiSi.sub.xN.sub.y being directly against the titanium nitride and the titanium nitride being directly against the metal silicide.
(40) In some embodiments, a method comprises forming a structure comprising polysilicon-comprising material, titanium-comprising material over the polysilicon-comprising material, silicon nitride-comprising material over the titanium-comprising material, and tungsten-comprising material over the silicon nitride-comprising material; and. The structure is annealed to cause at least a part of the silicon nitride to be converted into conductive material comprising titanium, silicon and nitrogen. In one embodiment, the polysilicon-comprising material consists essentially of (or consists of) polysilicon, the titanium-comprising material consists essentially of (or consists of) elemental titanium, the silicon nitride-comprising material consists essentially of (or consists of) silicon nitride, and the tungsten-comprising material consists essentially of (or consists of) elemental tungsten.
(41) In some embodiments, a conductive line construction comprises polysilicon-comprising material, a metal silicide directly against the polysilicon of the polysilicon-comprising material, elemental tungsten, TiSi.sub.xN.sub.y between the elemental tungsten and the metal silicide, and one of (a) or (b), with (a) being the TiSi.sub.xN.sub.y is directly against the metal silicide, and (b) being titanium nitride is between the TiSi.sub.xN.sub.y and the metal silicide, with the TiSi.sub.xN.sub.y being directly against the titanium nitride and the titanium nitride being directly against the metal silicide.
(42) In some embodiments, memory circuitry comprises an array of memory cells individually comprising a transistor having a pair of source/drain regions and a gate comprising a wordline. A storage element is electrically coupled to one of the source/drain regions and a digitline is electrically coupled to the other of the source/drain regions. At least one of the wordline and the digitline comprises polysilicon-comprising material, a metal silicide directly against the polysilicon of the polysilicon-comprising material, elemental tungsten, TiSi.sub.xN.sub.y between the elemental tungsten and the metal silicide, and one of (a) or (b), with (a) being the TiSi.sub.xN.sub.y is directly against the metal silicide, and (b) being titanium nitride is between the TiSi.sub.xN.sub.y and the metal silicide, with the TiSi.sub.xN.sub.y being directly against the titanium nitride and the titanium nitride being directly against the metal silicide.
(43) In some embodiments, a semiconductor device comprises a memory array comprising at least one digit-line, at least one word-line, and at least one memory cell electrically coupled to the at least one digit-line and the at least one word-line. At least one peripheral transistor comprises a gate electrode and a pair of source/drain regions. The at least one digit-line comprises the gate electrode of the at least one peripheral transistor. The gate of the at least one peripheral transistor comprises polysilicon-comprising material, metal silicide-comprising material over the polysilicon-comprising material, composite material including titanium, silicon and nitrogen-comprising material, and tungsten-comprising material over the composite material. In one embodiment, the polysilicon-comprising material consists essentially of (or consists of) polysilicon; the metal silicide-comprising material consists essentially of (or consists of) metal silicide; the titanium, silicon and nitrogen-comprising material consists essentially of (or consists of) titanium, silicon and nitrogen; and the tungsten-comprising material consists essentially of (or consists of) elemental tungsten.
(44) In compliance with the statute, the subject matter disclosed herein has been described in language more or less specific as to structural and methodical features. It is to be understood, however, that the claims are not limited to the specific features shown and described, since the means herein disclosed comprise example embodiments. The claims are thus to be afforded full scope as literally worded, and to be appropriately interpreted in accordance with the doctrine of equivalents.