Integrated assemblies, and methods of forming integrated assemblies
12581651 ยท 2026-03-17
Assignee
Inventors
- Gordon A. Haller (Boise, ID, US)
- William R. Kueber (Boise, ID, US)
- Zachary D. Beaman (Boise, ID, US)
- Christopher G. Shea (Boise, ID, US)
- Taehyun Kim (Boise, ID, US)
Cpc classification
H10B43/27
ELECTRICITY
H10W20/083
ELECTRICITY
H10B41/27
ELECTRICITY
H10W20/20
ELECTRICITY
International classification
H10B43/27
ELECTRICITY
H10B41/27
ELECTRICITY
Abstract
Some embodiments include a method in which a first stack is formed to include a metal-containing first layer, a second layer over the first layer, and a metal-containing third layer over the second layer. A first opening is formed to extend through the second and third layers. A sacrificial material is formed within the first opening. A second stack is formed over the first stack. A second opening is formed through the second stack, and is extended through the sacrificial material. First semiconductor material is formed within the second opening. A third opening is formed through the second stack and to the second layer. The second layer is removed to form a conduit. Conductively-doped second semiconductor material is formed within the conduit. Dopant is out-diffused from the conductively-doped second semiconductor material into the first semiconductor material. Some embodiments include integrated assemblies.
Claims
1. An integrated structure, comprising: a source structure comprising conductively-doped semiconductor material vertically sandwiched between an upper metal-containing material and a lower metal-containing material, the upper metal-containing material and the lower metal-containing material each independently consisting of one or more materials selected from the group consisting of one or more elemental metals, metal nitride, metal carbide and metal silicide; vertically-stacked conductive levels over the source structure; upper conductive levels of the vertically-stacked conductive levels being memory cell levels, and a lower conductive level of the vertically-stacked conductive levels being a select device level; channel material extending vertically along the memory cell levels and the select device level; a region of the channel material under the select device level being a lower region of the channel material; memory cell materials between the channel material and the vertically-stacked conductive levels, the memory cell materials comprising a tunneling material a charge-blocking material and a charge-storage material; the one or more memory cell materials being along portions of said lower region of the channel material; a first liner region comprising liner materials between the memory cell materials and the upper metal-containing material of the source structure, the liner materials comprising silicon oxide and metal nitride, the liner materials being absent from along the vertically-stacked conductive levels; a second liner region comprising the liner materials between the memory cell materials and the lower metal-containing material of the source structure; and a gap vertically disposed between the first and second liner regions, the gap extending laterally to vertically separate an upper region of the memory cell materials from a lower region of the memory cell materials.
2. The integrated structure of claim 1 wherein the upper and lower metal-containing materials are different compositions relative to one another.
3. The integrated structure of claim 1 wherein the upper and lower metal-containing materials are a same composition as one another.
4. The integrated structure of claim 3 wherein the upper and lower metal-containing materials comprise WSi, where the chemical formula indicates primary constituents rather than a specific stoichiometry.
5. The integrated structure of claim 1 wherein the first and second liner regions comprise titanium nitride.
6. The integrated structure of claim 1 wherein the first and second liner regions comprise a laminate configuration which includes titanium nitride over silicon dioxide.
7. The integrated structure of claim 1 wherein the conductively-doped semiconductor material comprises conductive-doped silicon.
8. The integrated structure of claim 1 wherein the conductive levels comprise metal.
9. The integrated structure of claim 8 wherein the conductive levels are spaced from one another by intervening levels comprising silicon dioxide.
10. An integrated assembly, comprising: a first stack comprising a metal-containing first layer, a second layer over the first layer, and a metal-containing third layer over the second layer, the second layer comprising conductively-doped first semiconductor material, the first and third layers comprising WSi, where the chemical formula indicates primary constituents rather than a specific stoichiometry; a first opening extending through the second and third layers of the first stack; a first liner material and a second liner material within the first opening, the first liner material comprising silicon oxide, the second liner material comprising metal nitride, the first and second liner materials having an upper region lining an upper portion of the first opening and a second region lining a lower portion of the first opening, the upper region being vertically spaced from the lower region by a first gap; a second stack over the first stack; the second stack having alternating first and second levels, the second levels comprising a conductive material; a second opening extending through the second stack directly over and adjoining the first opening, the first liner material and the second liner material being absent from the second opening; a channel material pillar extending though the second opening and into the first opening, a lower region of the channel material pillar being more heavily doped than an upper region of the channel material pillar, the lower region being in direct physical contact with the second layer of the first stack; memory material extending through the first opening and into the second opening, the memory material comprising a tunneling material, a charge-storage material and a charge blocking material; a second gap within the first opening, the second gap being vertically disposed between an upper portion of the memory material and a lower operation of the memory material, the second layer of the first stack extending laterally through the first gap and the second gap; a third opening through the second stack, through the third layer, and to the second layer; and an insulative material entirely filling the third opening.
11. The integrated assembly of claim 10 comprising memory cells along the first levels, with the memory cells comprising regions of the second semiconductor material; wherein the integrated assembly includes a memory device which comprises the memory cells; and wherein the first layer, the third layer and the conductively-doped second semiconductor material together form at least a portion of a source structure of the memory device.
12. The integrated assembly of claim 11 further comprising a source-select device.
13. The integrated assembly of claim 10 wherein the metal nitride comprises titanium nitride.
14. The integrated assembly of claim 10 wherein the metal-containing first layer and the metal-containing third layer comprise different compositions relative to one another.
15. The integrated assembly of claim 10 wherein the metal-containing first layer and the metal-containing third layer comprise the same composition.
16. The integrated assembly of claim 10 wherein the third opening extends into the second layer.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
(1)
(2)
(3)
(4)
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(6)
DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS
(7) Some embodiments include new methods of forming memory devices having vertically-stacked memory cell levels over a conductive source structure. The memory devices include at least one select device level (e.g., at least one SGS device level) between the memory cells levels and the conductive source structure. Channel material extends vertically along the memory cell levels and the select device level. A sacrificial material is initially provided in a region of the conductive source structure. The sacrificial material is replaced with conductively-doped semiconductor material, and dopant is out-diffused from the conductively-doped semiconductor material into a lower region of the channel material. The dopant within the lower region of the channel material may be provided to a desired location and concentration to form the doped region(s) of the select device level(s). Example embodiments are described below with reference to
(8) Referring to
(9) The base 12 may comprise semiconductor material; and may, for example, comprise, consist essentially of, or consist of monocrystalline silicon (Si). The base 12 may be referred to as a semiconductor substrate. The term semiconductor substrate means any construction comprising semiconductive material, including, but not limited to, bulk semiconductive materials such as a semiconductive wafer (either alone or in assemblies comprising other materials), and semiconductive material layers (either alone or in assemblies comprising other materials). The term substrate refers to any supporting structure, including, but not limited to, the semiconductor substrates described above. In some applications, the base 12 may correspond to a semiconductor substrate containing one or more materials associated with integrated circuit fabrication. Such materials may include, for example, one or more of refractory metal materials, barrier materials, diffusion materials, insulator materials, etc.
(10) A gap is provided between the base 12 and the insulative material 14 to indicate that there may be other materials, devices, etc., between the base 12 and the insulative material 14.
(11) The insulative material 14 may comprise any suitable composition(s); such as, for example, one or more of silicon dioxide, silicon nitride, aluminum oxide, etc.
(12) A stack 16 is formed over the insulative material 14. The stack 16 comprises a first layer 18, a second layer 20, and a third layer 22. The first, second and third layers comprise first, second and third materials 24, 26 and 28, respectively.
(13) In some embodiments, the first and third materials 24 and 28 may be metal-containing materials, and the first and third layers 18 and 22 may be referred to as metal-containing layers. In such embodiments, the first and third materials may comprise any suitable metal-containing composition(s); such as, for example, one or more of various metals (e.g., titanium, tungsten, cobalt, nickel, platinum, ruthenium, etc.) and/or metal-containing compositions (e.g., metal silicide, metal nitride, metal carbide, etc.). The first and third materials 24 and 28 may comprise a same composition as one another, or may comprise different compositions relative to one another. In some embodiments, the first and third materials 24 and 28 may comprise, consist essentially of, or consist of WSi, where the chemical formula indicates primary constituents rather than a specific stoichiometry. The WSi may be alternatively referred to as WSi.sub.x, where x is a number greater than zero.
(14) The first and third layers 18 and 22 may have any suitable thicknesses; and may be the same thickness as one another or may be different thickness relative to one another. In some embodiments, the first layer 18 will be thicker than the third layer 22. In some embodiments, the first layer 18 may have a thickness within a range of from about 500 angstroms () to about 2000 . In some embodiments, the third layer 22 may have a thickness within a range of from about 400 to about 1500 .
(15) The second material 26 may be a sacrificial material, and specifically may be a material which can be selectively removed relative to the first and third materials 24 and 28. For purposes of interpreting this disclosure and the claims follow, a material is considered to be selectively removable relative to another material if the material may be etched faster than the other material.
(16) In some embodiments, the second material 26 may comprise, consist essentially of, or consist of one or more metal nitrides (e.g., titanium nitride, tantalum nitride, tungsten nitride, etc.). For instance the second material 26 may comprise TiN, where the chemical formula indicates primary constituents rather than a specific stoichiometry.
(17) In some embodiments, the stack 16 may be referred to as a first stack to distinguish it from another stack formed at a later process stage. In some embodiments, the sacrificial material 26 may be referred to as a first sacrificial material to distinguish it from another sacrificial material formed at a later process stage.
(18) Referring to
(19) A liner 32 is formed to extend across an upper surface of the stack 16, and within the openings 30. The liner 32 comprises a laminate configuration which has a second liner material 36 over a first liner material 34. The liner materials 34 and 36 may be alternatively referred to as protective materials.
(20) The first liner material 34 may comprise any suitable composition(s); and in some embodiments may comprise, consist essentially of, or consist of silicon dioxide.
(21) The second liner material 36 may comprise any suitable composition(s); and in some embodiments may comprise, consist essentially of, or consist of one or more metal nitrides (e.g., one or more of tungsten nitride, titanium nitride, tantalum nitride, etc.). For instance, in some embodiments the second liner material 36 may comprise TiN, where the chemical formula indicates primary constituents rather than a specific stoichiometry.
(22) In some embodiments, the liner materials 34 and 36 may be referred to as first and second liners, respectively.
(23) The liner materials 34 and 36 may have any suitable thicknesses. In some embodiments, the liner material 34 may comprise silicon dioxide and may have a thickness within a range of from about 10 to about 500 , and the liner material 36 may comprise titanium nitride and may have a thickness within a range of from about 10 to about 150 .
(24) A sacrificial material 38 is formed to extend across the stack 16 and within the lined openings 30. The sacrificial material 38 is directly against the upper liner material 36 in the shown embodiment.
(25) In some embodiments, the sacrificial materials 26 and 38 may be referred to as first and second sacrificial materials, respectively.
(26) The material 38 may comprise any suitable composition(s) which is/are selectively removable relative to the liner material 36. In some embodiments, the liner material 36 comprises titanium nitride, and the sacrificial material 38 comprises, consists essentially of, or consists of tungsten. In such embodiments, the material 38 may be referred to as a tungsten-containing material.
(27) Referring to
(28) The remaining material 38 at the process stage of
(29) Referring to
(30) The base 12 (
(31) Referring to
(32) Referring to
(33) Referring to
(34) The semiconductor material 54 may comprise any suitable composition(s); and in some embodiments may comprise, consist essentially of, or consist of one or more of silicon, germanium, III/V semiconductor material (e.g., gallium phosphide), semiconductor oxide, etc.; with the term III/V semiconductor material referring to semiconductor materials comprising elements selected from groups III and V of the periodic table (with groups III and V being old nomenclature, and now being referred to as groups 13 and 15). In some embodiments, the semiconductor material 54 may comprise, consist essentially of, or consist of appropriately-doped silicon.
(35) In the illustrated embodiment, the channel material pillars 56 are annular rings (as shown in a top-down view of
(36) The channel material pillars 56 are spaced from the materials 48 and 50 of the stack 42 by intervening regions 60. The regions 60 comprise one or more cell materials (memory cell materials), with such cell materials being formed within the openings 52 prior to the channel material 54. The cell materials of the regions 60 may comprise tunneling material, charge-storage material, charge-blocking material and dielectric-barrier material. The tunneling material (also referred to as gate dielectric material) may comprise any suitable composition(s); and in some embodiments may comprise one or more of silicon dioxide, aluminum oxide, hafnium oxide, zirconium oxide, etc. The charge-storage material may comprise any suitable composition(s); and in some embodiments may comprise floating gate material (e.g., polysilicon) or charge-trapping material (e.g., one or more of silicon nitride, silicon oxynitride, conductive nanodots, etc.). The charge-blocking material may comprise any suitable composition(s); and in some embodiments may comprise one or more of silicon dioxide, aluminum oxide, hafnium oxide, zirconium oxide, etc. The dielectric-barrier material may comprise any suitable composition(s); and in some embodiments may comprise one or more of aluminum oxide, hafnium oxide, zirconium oxide, etc.
(37) Referring to
(38) The opening 62 has sidewall surfaces 63 which extend along the materials 48 and 50 of the stack 42. In the shown embodiment, the sidewall surfaces 63 are tapered. In other embodiments, the sidewall surfaces 63 may be substantially vertically straight; with the term substantially vertically straight meaning vertically straight to within reasonable tolerances of fabrication and measurement.
(39) Referring to
(40) The protective material 64 may comprise any suitable composition(s). In some embodiments, the protective material 64 may comprise, consist essentially of, or consist of silicon; and specifically may comprise silicon which is effectively undoped (e.g., comprising an intrinsic dopant concentration, and in some embodiments comprising a dopant concentration of less than or equal to about 10.sup.16 atoms/cm.sup.3).
(41) In the shown embodiment, the protective material 64 lines upper regions (portions) of the sidewall surfaces 63, and does not line lower regions of the sidewall surfaces 63. Specifically, the opening 62 is shown to extend through the third layer 22 and into the second layer 20, and the protective material 64 is along an upper portion of the third layer 22 and is not along a lower portion of the upper layer 22 or along the layer 20.
(42) Referring to
(43) Referring to
(44) Referring to
(45) The semiconductor material 68 may comprise any suitable composition(s); and in some embodiments may comprise, consist essentially of, or consist of one or more of silicon, germanium, III/V semiconductor material (e.g., gallium phosphide), semiconductor oxide, etc. In some embodiments, the semiconductor material 68 may comprise silicon which is heavily doped (e.g., doped to a concentration of at least about 10.sup.22 atoms/cm.sup.3) with n-type dopant (e.g., phosphorus).
(46) Referring to
(47) Dopant is out-diffused from the conductively-doped semiconductor material 68 into the semiconductor material (channel material) 54 to form heavily-doped regions 74 within lower portions of the channel material pillars 56. Stippling is utilized to indicate dopant within the heavily-doped regions 74.
(48) The out-diffusion from the doped material 68 into the semiconductor material 54 may be accomplished with any suitable processing, including, for example, suitable thermal processing (e.g., thermal processing at a temperature exceeding about 300 C. for a duration of at least about two minutes).
(49) Referring to
(50) The first levels 44 of
(51) Referring to
(52) The assembly 10 of
(53) The memory cells 80 (e.g., NAND memory cells) are vertically stacked one atop another. The memory cells 80 are along the first levels 44. Each of the memory cells comprises a region of the semiconductor material (channel material) 54, and comprises regions (control gate regions) of the conductive levels 44. The regions of the conductive levels which are not comprised by the memory cells 80 may be considered to be wordline regions (or routing regions) which couple the control gate regions with driver circuitry and/or with other suitable circuitry. The memory cells 80 also comprise the cell materials (e.g., the tunneling material, charge-storage material, dielectric-barrier material and charge-blocking material) within the regions 60.
(54) In some embodiments, the conductive levels 44 associated with the memory cells 80 may be referred to as wordline/control gate levels (or memory cell levels), in that they include wordlines and control gates associated with vertically-stacked memory cells of NAND strings. The NAND strings may comprise any suitable number of memory cell levels. For instance, the NAND strings may have 8 memory cell levels, 16 memory cell levels, 32 memory cell levels, 64 memory cell levels, 512 memory cell levels, 1024 memory cell levels, etc.
(55) The conductive materials 24, 68 and 28 together form a source structure 76 of the memory device 10. The source structure may be analogous to the source structures 216 described in the Background section. The source structure is shown to be coupled with control circuitry (e.g., CMOS). The control circuitry may be under the source structure 76 (e.g., may be associated with the base 12 of
(56) In some embodiments, the channel material pillars 56 may be considered to be representative of a large number of substantially identical channel material pillars extending across the memory device 10; with the term substantially identical meaning identical to within reasonable tolerances of fabrication and measurement. The top-down view of
(57) In some embodiments, the region of the channel material 54 beneath the SGS layer 44a of
(58) The assemblies and structures discussed above may be utilized within integrated circuits (with the term integrated circuit meaning an electronic circuit supported by a semiconductor substrate); 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.
(59) Unless specified otherwise, the various materials, substances, compositions, etc. described herein may be formed with any suitable methodologies, either now known or yet to be developed, including, for example, atomic layer deposition (ALD), chemical vapor deposition (CVD), physical vapor deposition (PVD), etc.
(60) The terms dielectric and insulative may be utilized to describe materials having insulative electrical properties. The terms are considered synonymous in this disclosure. The utilization of the term dielectric in some instances, and the term insulative (or electrically insulative) in other instances, may be to provide language variation within this disclosure to simplify antecedent basis within the claims that follow, and is not utilized to indicate any significant chemical or electrical differences.
(61) The terms electrically connected and electrically coupled may both be utilized in this disclosure. The terms are considered synonymous. The utilization of one term in some instances and the other in other instances may be to provide language variation within this disclosure to simplify antecedent basis within the claims that follow.
(62) The particular orientation of the various embodiments in the drawings is for illustrative purposes only, and the embodiments may be rotated relative to the shown orientations in some applications. The descriptions provided herein, and the claims that follow, pertain to any structures that have the described relationships between various features, regardless of whether the structures are in the particular orientation of the drawings, or are rotated relative to such orientation.
(63) The cross-sectional views of the accompanying illustrations only show features within the planes of the cross-sections, and do not show materials behind the planes of the cross-sections, unless indicated otherwise, in order to simplify the drawings.
(64) When a structure is referred to above as being on, adjacent or against another structure, it can be directly on the other structure or intervening structures may also be present. In contrast, when a structure is referred to as being directly on, directly adjacent or directly against another structure, there are no intervening structures present. The terms directly under, directly over, etc., do not indicate direct physical contact (unless expressly stated otherwise), but instead indicate upright alignment.
(65) Structures (e.g., layers, materials, etc.) may be referred to as extending vertically to indicate that the structures generally extend upwardly from an underlying base (e.g., substrate). The vertically-extending structures may extend substantially orthogonally relative to an upper surface of the base, or not.
(66) Some embodiments include a method of forming an integrated assembly. A first stack is formed to include a metal-containing first layer, a second layer over the first layer, and a metal-containing third layer over the second layer. The second layer includes a first sacrificial material. A first opening is formed to extend through the second and third layers of the first stack. A second sacrificial material is formed within the first opening. A second stack is formed over the first stack. The second stack has alternating first and second levels. A second opening is formed to pass through the second stack and to the second sacrificial material. The second opening is extended through the second sacrificial material. First semiconductor material is formed within the extended second opening. A third opening is formed to pass through the second stack, through the third layer, and to the first sacrificial material of the second layer. The first sacrificial material of the second layer is removed to form a conduit. Conductively-doped second semiconductor material is formed within the conduit. Dopant is out-diffused from the conductively-doped second semiconductor material into the first semiconductor material. The out-diffused dopant extends upwardly to at least one of the first levels. Conductive material is formed within the first levels.
(67) Some embodiments include a method of forming an integrated assembly. A first stack is formed to comprise a first layer, a second layer over the first layer, and a third layer over the second layer. The first and third layers comprise WSi, where the chemical formula indicates primary constituents rather than a specific stoichiometry. The second layer comprises TiN, where the chemical formula indicates primary constituents rather than a specific stoichiometry. A first opening is formed to extend through second and third layers of the first stack. A liner is formed within the first opening to line the first opening. The liner comprises a laminate configuration containing a second material over a first material. The first material comprises silicon dioxide. The second material comprises titanium nitride. A tungsten-containing plug is formed within the lined first opening. A second stack is formed over the first stack. The second stack has alternating first and second levels. A second opening is formed to pass through the second stack and to the tungsten-containing plug. The tungsten-containing plug is removed to extend the second opening. First semiconductor material is formed within the extended second opening. A third opening is formed to pass through the second stack, through the third layer, and to the second layer. Upper portions of the sidewall surfaces of the third opening are lined with protective material. After forming the protective material, the second layer is removed to form a conduit. Conductively-doped second semiconductor material is formed within the conduit. Dopant is out-diffused from the conductively-doped second semiconductor material into the first semiconductor material. The out-diffused dopant extends upwardly to at least one of the first levels. Conductive material is formed within the first levels. Insulative material is formed within the third opening.
(68) Some embodiments include an integrated structure comprising a source structure which includes conductively-doped semiconductor material vertically sandwiched between an upper metal-containing material and a lower metal-containing material. Vertically-stacked conductive levels are over the source structure. Upper conductive levels of the vertically-stacked conductive levels are memory cell levels, and a lower conductive level of the vertically-stacked conductive levels is a select device level. Channel material extends vertically along the memory cell levels and the select device level. A region of the channel material under the select device level is a lower region of the channel material. One or more memory cell materials are between the channel material and the vertically-stacked conductive levels. The one or more memory cell materials are along portions of said lower region of the channel material. A first liner region is between the memory cell materials and the upper metal-containing material of the source structure. A second liner region is between the memory cell materials and the lower metal-containing material of the source structure. A gap is between the first and second liner regions.
(69) 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.