METHODS, APPARATUS, AND SYSTEM FOR PROTECTING COBALT FORMATIONS FROM OXIDATION DURING SEMICONDUCTOR DEVICE FORMATION
20200168504 ยท 2020-05-28
Assignee
Inventors
Cpc classification
H01L21/76897
ELECTRICITY
H01L27/0886
ELECTRICITY
H01L21/823431
ELECTRICITY
H01L21/76849
ELECTRICITY
H01L21/76834
ELECTRICITY
H01L29/41791
ELECTRICITY
H01L29/785
ELECTRICITY
H01L21/823821
ELECTRICITY
H01L29/66795
ELECTRICITY
International classification
H01L21/768
ELECTRICITY
H01L29/66
ELECTRICITY
H01L29/417
ELECTRICITY
Abstract
Methods comprising forming a cobalt formation on an active feature of a semiconductor device, wherein the semiconductor device comprises an inactive feature above the cobalt formation; forming a cap on the cobalt formation; removing at least a portion of the inactive feature, wherein the cobalt formation is substantially not removed; forming a dielectric material above the cap; and forming a first contact to the cobalt formation. Systems configured to implement the methods. Semiconductor devices produced by the methods.
Claims
1-7. (canceled)
8. A semiconductor device, comprising: a plurality of active features; a cobalt formation disposed on at least two of the active features; a cap on the cobalt formation; a dielectric material on the cap on the cobalt formation on at least one active feature; and a first contact on the cap on the cobalt formation on at least one other active feature.
9. The semiconductor device of claim 8, wherein the cap comprises a material selected from tungsten, ruthenium, titanium, silicon, or silicide.
10. The semiconductor device of claim 9, wherein the cap comprises a material selected from tungsten or ruthenium.
11. The semiconductor device of claim 10, wherein the cap comprises tungsten.
12. The semiconductor device of claim 8, wherein the dielectric material is selected from silicon oxide or silicon carbon oxide (SiOC).
13. The semiconductor device of claim 8, wherein the first contact comprises tungsten, copper, aluminum, or cobalt.
14. The semiconductor device of claim 8, further comprising a plurality of gates, a plurality of sources, and a plurality of drains, wherein each source is adjacent to one of the plurality of gates and each drain is adjacent to one of the plurality of gates; each one of the active feature is one of the plurality of sources or one of the plurality of drains; and a second contact to one of the plurality of gates.
15-20. (canceled)
21. A semiconductor device, comprising: a plurality of fins, each fin having a long axis in a first direction; a cobalt formation disposed on at least two of the fins, wherein the cobalt formation has a long axis in a second direction perpendicular to the first direction; a cap on the cobalt formation; a dielectric material on the cap on the cobalt formation on at least one fin; and a first contact on the cap on the cobalt formation on at least one other fin.
22. The semiconductor device of claim 21, wherein the cap comprises a material selected from tungsten, ruthenium, titanium, silicon, or silicide.
23. The semiconductor device of claim 22, wherein the cap comprises a material selected from tungsten or ruthenium.
24. The semiconductor device of claim 23, wherein the cap comprises tungsten.
25. The semiconductor device of claim 21, wherein the dielectric material is selected from silicon oxide or silicon carbon oxide (SiOC).
26. The semiconductor device of claim 21, wherein the first contact comprises tungsten, copper, aluminum, or cobalt.
27. The semiconductor device of claim 21, further comprising a plurality of gates, a plurality of sources, and a plurality of drains, wherein each source is adjacent to one of the plurality of gates and each drain is adjacent to one of the plurality of gates; each fin provides at least one source or at least one drain; and a second contact to one of the plurality of gates.
28. A semiconductor device, comprising: a plurality of fins, each fin having a long axis in a first direction; a plurality of sources and drains, wherein one source and one drain are each disposed on one fin of the plurality of fins; a plurality of gates, each having a long axis in a second direction perpendicular to the first direction and each disposed over at least two of the fins, wherein one source is adjacent to one of the plurality of gates and one drain is adjacent to one of the plurality of gates; a plurality of cobalt formations, each cobalt formation disposed over one source or one drain of at least two of the fins, wherein the cobalt formation has a long axis in the second direction; a cap on each cobalt formation, wherein the cap comprises a material selected from tungsten, ruthenium, titanium, silicon, or silicide; a dielectric material on the cap on each cobalt formation on at least one fin, wherein the dielectric material is selected from silicon oxide or silicon carbon oxide (SiOC); and a first contact on the cap on the cobalt formation on at least one other fin, wherein the first contact comprises tungsten, copper, aluminum, or cobalt; and a second contact to one of the plurality of gates, wherein the first contact comprises tungsten, copper, aluminum, or cobalt.
29. The semiconductor device of claim 28, wherein the cap comprises a material selected from tungsten or ruthenium.
30. The semiconductor device of claim 29, wherein the cap comprises tungsten.
31. The semiconductor device of claim 28, further comprising a shallow trench isolation (STI) between the fins.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0013] The disclosure may be understood by reference to the following description taken in conjunction with the accompanying drawings, in which like reference numerals identify like elements, and in which:
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[0026] While the subject matter disclosed herein is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawings and are herein described in detail. It should be understood, however, that the description herein of specific embodiments is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the intention is to cover all modifications, equivalents, and alternatives falling within the spirit and scope of the disclosure as defined by the appended claims.
DETAILED DESCRIPTION
[0027] Various illustrative embodiments of the disclosure are described below. In the interest of clarity, not all features of an actual implementation are described in this specification. It will, of course be appreciated that, in the development of any such actual embodiment, numerous implementation-specific decisions must be made to achieve the developers' specific goals, such as compliance with system-related and business-related constraints, which will vary from one implementation to another. Moreover, it will be appreciated that such a development effort might be complex and time-consuming, but would be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.
[0028] The present subject matter will now be described with reference to the attached figures. Various structures, systems and devices are schematically depicted in the drawings for purposes of explanation only and to not obscure the present disclosure with details that are well known to those skilled in the art. Nevertheless, the attached drawings are included to describe and explain illustrative examples of the present disclosure. The words and phrases used herein should be understood and interpreted to have a meaning consistent with the understanding of those words and phrases by those skilled in the relevant art. No special definition of a term or phrase, i.e., a definition that is different from the ordinary and customary meaning as understood by those skilled in the art, is intended to be implied by consistent usage of the term or phrase herein. To the extent that a term or phrase is intended to have a special meaning, i.e., a meaning other than that understood by skilled artisans, such a special definition will be expressly set forth in the specification in a definitional manner that directly and unequivocally provides the special definition for the term or phrase.
[0029] Embodiments herein are directed to semiconductor devices comprising cobalt formations that are protected from oxidation, and methods and systems for forming such devices.
[0030] Turning to
[0031] The semiconductor structure 100 comprises a plurality of fins 104a, 104b, 104c, 104d, 104e and 104f are formed. The fins 104a-f may be formed by etching a semiconductor substrate (not shown in
[0032] Each fin 104a-f generally has a long horizontal dimension and a short horizontal dimension perpendicular to the long horizontal dimension. The section from which the view of
[0033]
[0034]
[0035] Between gates 106a-f are disposed a plurality of cobalt formations 108a, 108b, 108c, and 108d. Each of the cobalt formations 108a-d comprises cobalt. Though not to be bound by theory, cobalt may provide effective electrical communication between an active feature, e.g., an epitaxial source/drain (not shown in
[0036] At the stage of fabrication depicted in
[0037] Subsequent stylized cross-sectional depictions of the semiconductor device 100 according to embodiments herein will be taken along the depicted X-cut through and perpendicular to the long axes of gates 106a-f and cobalt formations 108a-d, and through and parallel to the long axes of fins 104b and 104e. One or more of the subsequent cross-sectional views may depict the semiconductor device 100 before the processing stage shown in
[0038]
[0039] The fins 104b, 104e (along with the other fins 104a, 104c, 104d, and 104f shown in
[0040] Each gate 106a-106f is disposed on the fins 104b, 104e as described above. Self-aligned caps 212a-212f are disposed on the tops of the gates 106a-106f In one embodiment, each of the self-aligned caps 212a-212f comprises silicon nitride (SiN). Disposed on the sides of the gates 106a-106f and self-aligned caps 212a-212f are sets of left spacers 213a-213f and right spacers 214a-214f. The terms left and right are used here for convenience only in describing the embodiments depicted in
[0041] In addition, each left spacer 213a-f and each right spacer 214a-f may be referred to herein as an inactive feature.
[0042] The self-aligned caps 212a-212f, the left spacers 213a-213f, and the right spacers 214a-214f may be formed using techniques known in the art.
[0043] Also disposed on and/or in the fins 104b, 104e are sources 220a, 220c and drains 220b, 220d. In one embodiment, the sources 220a, 220c and the drains 220b, 220d comprise epitaxial silicon, epitaxial silicon-germanium, doped epitaxial silicon, or doped epitaxial silicon-germanium. Each of the sources 220a, 220c and the drains 220b, 220d may be considered an active feature, as the term is used herein. In addition, each gate 106a-106f may additionally be considered an active feature.
[0044] Even though at least one spacer 213 or 214 lies between each source 220a, 220c or each drain 220b, 220d, on the one hand, and a gate 106a-f on the other, each of the sources and drains 220a-220d may be referred to as being adjacent to a gate, e.g. gate 106b or gate 106e.
[0045] Further, the semiconductor device 100 depicted in
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[0047] The stage of processing depicted in
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[0050] After performing the fourth stage of processing and as depicted in
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[0052] In one embodiment, each cap 640a-640d comprises a material selected from tungsten, ruthenium, titanium, silicon, or silicide. In a further embodiment, each cap 640a-640d comprises a material selected from tungsten or ruthenium. In a more particular embodiment, each cap 640a-640d comprises tungsten.
[0053] The caps 640a-640d may be formed by any selective formation process known to the person of ordinary skill in the art. In one embodiment, the caps 640a-640d may be formed by a process comprising wet cleaning the top surfaces of cobalt formations 108a-108d and subsequent selective deposition of e.g., tungsten.
[0054] In contrast to one prior art solution, the present method does not require the caps 640a-640d to comprise SiC to inhibit oxidation of cobalt formations 108a-108d.
[0055]
[0056] Removal of the portions of the inactive features may be performed by any known technique, such as RIE.
[0057] As depicted in
[0058]
[0059] In one embodiment, the dielectric material is selected from silicon oxide or silicon carbon oxide (SiOC). Though not to be bound by theory, each cap 640a-640d may protect each underlying cobalt formation 108a-108d from damage when forming dielectric structures 845a-845d from silicon oxide or SiOC.
[0060]
[0061]
[0062] In one embodiment, as depicted in
[0063] In contrast to a prior art solution, in which gate contacts are only formed in STI regions, the present method allows formation of a gate contact (e.g., second contact 110b) over a fin (e.g., fin 104b).
[0064] Although
[0065] In subsequent processing stages (not shown), the ESL 950 may be removed, the first contact 110a and the second contact 110b may be planarized, and additional layers of the semiconductor device 100 may be formed.
[0066]
[0067] The method 1100 additionally comprises removing (at 1130) at least a portion of the inactive feature, wherein the cobalt formation is substantially not removed. The method 1100 further comprises forming (at 1140) a dielectric material above the cap. In one embodiment, forming (at 1140) comprises forming the dielectric material from silicon oxide or silicon carbon oxide (SiOC).
[0068] The method 1100 still further comprises forming (at 1150) a first contact to the cobalt formation. In one embodiment, forming (at 1150) comprises forming the first contact from tungsten, ruthenium, molybdenum, copper, aluminum, or cobalt.
[0069] In one embodiment, the method 1100 further comprises forming (at 1160) a plurality of gates, a plurality of sources, and a plurality of drains in the semiconductor device, wherein each source is adjacent to one of the plurality of gates and each drain is adjacent to one of the plurality of gates, wherein the active feature is one of the plurality of sources or one of the plurality of drains. In this embodiment, the method 1100 may also further comprise forming (at 1170) a second contact to one of the plurality of gates.
[0070] Turning now to
[0071] The semiconductor device processing system 1212 may comprise various processing stations, such as etch process stations, photolithography process stations, CMP process stations, etc. One or more of the processing steps performed by the processing system 1212 may be controlled by the processing controller 1220. The processing controller 1220 may be a workstation computer, a desktop computer, a laptop computer, a tablet computer, or any other type of computing device comprising one or more software products that are capable of controlling processes, receiving process feedback, receiving test results data, performing learning cycle adjustments, performing process adjustments, etc.
[0072] The semiconductor device processing system 1212 may produce integrated circuits on a medium, such as silicon wafers 1215. The processing system 1212 may provide processed silicon wafers 1215 on a transport mechanism 1250, such as a conveyor system. In some embodiments, the conveyor system may be sophisticated clean room transport systems that are capable of transporting semiconductor wafers. In one embodiment, the semiconductor device processing system 1212 may perform one or more processing steps, e.g., one or more of those described above and depicted in
[0073] In some embodiments, the items labeled 1215 may represent individual wafers, and in other embodiments, the items 1215 may represent a group of semiconductor wafers, e.g., a lot of semiconductor wafers. Each wafer 1215 may comprise a transistor, a capacitor, a resistor, a memory cell, a processor, and/or the like. In one embodiment, the wafer 1215 includes a plurality of transistors.
[0074] The system 1200 may be capable of performing analysis and manufacturing of various products involving various technologies. For example, the system 1200 may use design and production data for manufacturing devices of CMOS technology, Flash technology, BiCMOS technology, power devices, memory devices (e.g., DRAM devices), NAND memory devices, and/or various other semiconductor technologies.
[0075] The semiconductor device processing system 1212 may be adapted to perform one or more of the following:
[0076] form a cobalt formation on an active feature of a semiconductor device, wherein the semiconductor device comprises an inactive feature above the cobalt formation;
[0077] form a cap on the cobalt formation;
[0078] remove at least a portion of the inactive feature, wherein the cobalt formation is substantially not removed;
[0079] form a dielectric material above the cap; and
[0080] form a first contact to the cobalt formation.
[0081] In one embodiment, the semiconductor device processing system is adapted to form the cap from a material selected from tungsten, ruthenium, titanium, silicon, or silicide. In a further embodiment, the semiconductor device processing system is adapted to form the cap from tungsten or ruthenium. In a particular embodiment, the semiconductor device processing system is adapted to form the cap from tungsten.
[0082] In one embodiment, the semiconductor device processing system is adapted to form the dielectric material from silicon oxide or silicon carbon oxide (SiOC).
[0083] In one embodiment, the semiconductor device processing system is further adapted to perform one or more of the following:
[0084] form a plurality of gates, a plurality of sources, and a plurality of drains in the semiconductor device, wherein each source is adjacent to one of the plurality of gates and each drain is adjacent to one of the plurality of gates; wherein the active feature is one of the plurality of sources or one of the plurality of drains, and
[0085] form a second contact to one of the plurality of gates.
[0086] The methods described above may be governed by instructions that are stored in a non-transitory computer readable storage medium and that are executed by, e.g., a processor in a computing device. Each of the operations described herein may correspond to instructions stored in a non-transitory computer memory or computer readable storage medium. In various embodiments, the non-transitory computer readable storage medium includes a magnetic or optical disk storage device, solid-state storage devices such as flash memory, or other non-volatile memory device or devices. The computer readable instructions stored on the non-transitory computer readable storage medium may be in source code, assembly language code, object code, or other instruction format that is interpreted and/or executable by one or more processors.
[0087] The particular embodiments disclosed above are illustrative only, as the disclosure may be modified and practiced in different but equivalent manners apparent to those skilled in the art having the benefit of the teachings herein. For example, the process steps set forth above may be performed in a different order. Furthermore, no limitations are intended to the details of construction or design herein shown, other than as described in the claims below. It is, therefore, evident that the particular embodiments disclosed above may be altered or modified and all such variations are considered within the scope and spirit of the disclosure. Accordingly, the protection sought herein is as set forth in the claims below.