METHOD, APPARATUS AND SYSTEM FOR A HIGH DENSITY MIDDLE OF LINE FLOW
20170263715 · 2017-09-14
Inventors
- Guillaume Bouche (Albany, NY, US)
- Tuhin Guha Neogi (Fishkill, NY, US)
- Sudharshanan Raghunathan (Santa Clara, CA, US)
- Andy Chi-Hung Wei (Queensbury, NY, US)
- Jason Eugene Stephens (Hopewell Junction, NY, US)
- Vikrant Kumar Chauhan (Clifton Park, NY, US)
- David Michael Permana (Ballston Spa, NY, US)
Cpc classification
H01L21/76897
ELECTRICITY
H01L29/4966
ELECTRICITY
H01L21/76895
ELECTRICITY
H01L29/41791
ELECTRICITY
H01L21/76816
ELECTRICITY
H01L21/31055
ELECTRICITY
H01L21/02126
ELECTRICITY
H01L23/485
ELECTRICITY
H01L29/6653
ELECTRICITY
H01L29/6656
ELECTRICITY
H01L21/0273
ELECTRICITY
International classification
H01L29/40
ELECTRICITY
H01L21/027
ELECTRICITY
H01L29/49
ELECTRICITY
H01L29/66
ELECTRICITY
H01L21/02
ELECTRICITY
H01L21/768
ELECTRICITY
Abstract
At least one method, apparatus and system disclosed herein for forming a finFET device. A gate structure comprising a gate spacer on a semiconductor wafer is formed. A self-aligned contact (SAC) cap is formed over the gate structure. A TS structure is formed. At least one M0 metal structure void is formed. At least one CB structure void adjacent the M0 metal structure void is formed. An etch process is performed the M0 and CB structures voids to the gate structure. At least one CA structure void adjacent the CB structure void is formed. The M0, CB, and CA structure voids are metallized.
Claims
1. A method for forming a finFET device, comprising: forming a gate structure comprising a gate spacer on a semiconductor wafer; forming a self-aligned contact (SAC) cap over said gate structure; forming a TS structure; forming at least one M0 metal structure void; forming at least one CB structure void adjacent said M0 metal structure void; etching below said M0 and CB structures voids to the gate structure; forming at least one CA structure void adjacent said CB structure void; and metallizing said M0, CB, and CA structure voids.
2. The method of claim 1, wherein forming said SAC cap over said gate structure comprises forming a T-shaped SAC cap over said gate structure, comprising: removing a top portion of the gate spacer; and replacing the top portion by deposing a nitride material;
3. The method of claim 1, wherein removing said top portion of the gate spacer comprises performing an SiOC isotropic etch process.
4. The method of claim 1, wherein forming said TS structure comprises: depositing a lithography stack in the location for said TS structure; performing an etch process for removing an SiO2 oxide portion and exposing a sidewall of said gate structure; removing said lithography stack; depositing an SiOC material on said location for said TS structure; performing a CMP process over said SiOC material performing an etch process for removing SiO.sub.2 material selective to said SiOC material; performing an etch process on said location for said TS structure for forming a TS structure void; removing sidewall and bottom material from said TS structure void; and performing a metallization process to form said TS structure.
5. The method of claim 4, wherein performing said metallization process to form said TS structure comprises: depositing a first metal liner in said TS structure void; depositing a Ti-nitride material in said TS structure void; and depositing a tungsten material in said TS structure void
6. The method of claim 1, wherein forming said at least one M0 metal structure void comprises: depositing a dielectric layer; depositing a titanium-nitride (TiN) layer over said dielectric layer depositing a memorization layer over said TiN layer; depositing a first lithography stack above said memorization layer; patterning a first M0 metal structure; performing an etch process to transfer said first M0 structure into said memorization layer; removing said first lithography stack depositing a second lithography stack above said memorization layer; patterning a second M0 structure; performing an etch process to transfer said second M0 metal structure into said memorization layer; and removing said second lithography stack; performing at least one of an etch or punch process on said first and second M0 metal structures through the TiN layer to form a first M0 metal structure void and a second M0 metal structure void.
7. The method of claim 6, wherein performing said punch process comprises removing all materials within the patterned areas of said first and second M0 metal structures down to the dielectric layer.
8. The method of claim 1, wherein forming said at least one CB structure void comprises: depositing a dielectric layer; depositing an etch-stop layer over said dielectric layer; depositing a memorization layer over said etch-stop layer; depositing a first lithography stack above said memorization layer; patterning a first CB structure; performing a memorization process for said first CB structure into said memorization layer; removing said first lithography stack; depositing a second lithography stack above said memorization layer; patterning a second CB structure; performing a memorization process for said second CB structure into said memorization layer; removing said second lithography stack; and performing at least one of an etch or punch process on said first and second CB structures through the etch stop layer to form a first CB structure void and a second CB structure void.
9. The method of claim 8, wherein depositing said first and second lithography stacks each comprise depositing an organic planarization layer and depositing a photoresist layer above said organic planarization layer.
10. The method of claim 8, further comprising etching said CB and M0 structure voids down to said gate structure such that said CB and M0 structure voids are merged.
11. The method of claim 1, wherein forming said at least one CB structure comprises forming said at least one CB structure to self-align into said at least one M0 metal structure.
12. The method of claim 1, wherein forming at least one CA structure void comprises: depositing a light-absorbing organic mix layer; depositing a first lithography stack above said organic mix layer; patterning a first CA structure; removing said first lithography stack; depositing a second lithography stack above said organic mix layer; patterning a second CA structure; removing said second lithography stack; and performing a punch process on said first and second CA structures to form a first CA structure void and a second CA structure void.
13. The method of claim 12, further comprising: depositing a memorization layer over said organic mix layer; performing a memorization process for said first CA structure on said memorization layer; and performing a memorization process for said second CA structure on said memorization layer.
14. The method of claim 1, further comprising providing a functional cell having cross coupled devices.
15. A method for forming a finFET device, comprising: forming a gate structure comprising a gate spacer on a semiconductor wafer; removing a top portion of the gate spacer; replacing the top portion by deposing a nitride material; forming a borderless TS structure; forming at least one M0 metal structure void; forming at least one CB structure void adjacent said M0 metal structure void; etching below said M0 and CB structures voids to the gate structure such that said CB and M0 structure voids are merged; forming at least one CA structure void adjacent said CB structure void; and performing metal filling in said M0, CB, and CA structure voids for forming a functional cell having cross couple.
16. The method of claim 15, further comprising performing a chemical mechanical polishing (CMP) process upon said nitride material to form a T-shaped self-aligned contact (SAC) cap over said gate structure.
17. The method of claim 15, wherein: forming at least one CB structure void comprises performing CB double patterning process; forming at least one M0 structure void comprises performing M0 double patterning process; and forming at least one CA structure void comprises performing CA double patterning process.
18. A system, comprising: a semiconductor device processing system to manufacture a semiconductor device comprising at least one fin field effect transistor (finFET); and a processing controller operatively coupled to said semiconductor device processing system, said processing controller configured to control an operation of said semiconductor device processing system; wherein said semiconductor device processing system is adapted to: form a gate structure comprising a gate spacer on a semiconductor wafer; form a self-aligned contact (SAC) cap over said gate structure; form a TS structure; form at least one M0 metal structure void; form at least one CB structure void adjacent said M0 metal structure void; etch below said M0 and CB structures voids to the gate structure; form at least one CA structure void adjacent said CB structure void; and perform metal filling in said M0, CB, and CA structure voids.
19. The system of claim 18, further comprising a design unit configured to generate a first design comprising a definition for a functional cell having cross couple, wherein data from said design unit is used by said process controller to control an operation of said semiconductor device processing system.
20. The system of claim 18, wherein said semiconductor device processing system is further adapted to process semiconductor wafers to form functional cells characterized by a 10 nm architecture having 31.5 nm fin pitch in a 7.5 nm track design at 42 nm metal pitch for processing cross couple.
Description
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] 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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[0031] 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 invention 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 invention as defined by the appended claims.
DETAILED DESCRIPTION
[0032] Various illustrative embodiments of the invention 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 nevertheless be a routine undertaking for those of ordinary skill in the art having the benefit of this disclosure.
[0033] The present subject matter will now be described with reference to the attached figs. Various structures, systems and devices are schematically depicted in the drawings for purposes of explanation only and so as 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.
[0034] Embodiments herein provide for a 10 nm architecture that is capable of providing 31.5 nm fin pitch in a 7.5 nm track design at 42 nm metal (Mx, wherein x=0, 1, 2, 3, . . . ) pitch for processing cross couple. Embodiments herein provide for a self-aligned to gate borderless TS, as well as a self-aligned to gate local interconnect structure (i.e., CA structure). In embodiments herein, another local interconnect structure (i.e., CB structure) may be self-aligned, to the M0 line above. The design provided by embodiments herein provides for obviating the need for V0 (via) because the M0 of embodiments herein is designed to land directly on CB. Further, M0 may be unidirectional, wherein the M1 of previous designs is replaced by the M0. Further, the M2 of previous designs may be replaced by M1. Embodiments herein provide for a six mask middle of line (MOL) process, wherein the first level metal is not needed to finish a standard cell. That is, the first level metal may be used as the routing level.
[0035] Although not limited to specific embodiments disclosed in the present disclosure, exemplary embodiments herein provide for processing a semiconductor wafer for forming a device comprising a plurality of fins having 31.5 nm in a horizontal configuration in a 10 nm architecture. Further, the device may comprise vertical gates with contacted poly pitch (CPP) of 63 nm using LELE processing. The vertical M0 metal structure may be of 42 nm LELE with LELE CB vias and tabs on active structures.
[0036] The device of embodiments herein may also comprise horizontal CA structures formed using LELE processing, wherein the CA structures may be in the form of bars and/or vias. The M1 metal lines of the structures may be horizontally formed using 42 nm self-aligning double pattering (SADP) processing utilizing two blocks or cut masks. The M2 metal lines of the device may be may be vertically formed using 42 nm SADP processing utilizing one cut mask. The M3 metal lines of the device may be may be horizontally formed using 42 nm SADP processing utilizing one cut mask. In one embodiment, 42 nm measurement is selected as a limit to allow for printing SADP at various sizes required to form SRAM M2 word lines. Further, the 42 nm measurement may be utilized for potential sizing usage in logic routing levels.
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[0038] Moreover, a plurality of fins 510 are formed on the layer 502 and comprise respective end portions 510E and a central portion 510C, which is covered by a gate electrode structure 520. Furthermore, a gate insulation material may be formed at least on sidewalls of the fins 510 (not shown in
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[0044] In one embodiment, the replaced metal gates are recessed by means of an etch. Also a partial SiOC isotropic etch process may be performed to remove the top portion of the gate spacer 521, leaving exposed an outer nitride sidewall from the liner 710 (
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[0047] An etch oxide process may then be performed (
[0048] A wet etch SiO.sub.2 diluted HF process may then be performed (
[0049] Subsequently, the POC liner etch, also referred to as contact etch stop layer (CESL) punch-process, is performed to remove the sidewalls of the trench 1510, resulting in a larger trench 1610 (
[0050] Subsequently, the trench 1610 is metallized (
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[0052] The lithography stack 1840 is then etched, wherein the M0 patterns 1850a, 1850b are “memorized” into the oxide layer 1830 (
[0053] The lithography stack 2040 is then etched, wherein the M0 patterns 1850c and 1850d are also memorized into the oxide layer 1830 (
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[0055] The lithography stack 2340 is then etched, wherein the CB patterns 2350a, 2350b are “memorized” into the memorization layer 2320 (
[0056] The lithography stack 2540 is then etched, wherein the CB patterns 2350c and 2350d are also memorized into the oxide layer 2340 (
[0057] The oxide layer 2320, the etch stop layer 2315 are both etched away during the CB patterning. The dielectric etch is pursued that presents selectivity to Ti-Nitride. As a result, the Ti-Nitride layer 1820 is at a point exposed within the CB openings into the organic layer 2310, acts as a block to the etch while the CB via gets further etched into dielectric layer 1810 through the pre-existing M0 openings into Ti-Nitride. The organic layer 2310 gets in turn fully etched away (
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[0059] A Ti-Nitride stripping process may be performed to remove the Ti-Nitride layer 1830 (
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[0061] The second part of the CA double patterning is then performed. Another lithography stack 3540 is deposited on the patterned organic mix layer 3210 (
[0062] The lithography stack 3540 is then etched, wherein the CA pattern 3350b is formed into and through the organic mix layer 3210 (
[0063] An etch process for removing the sacrificial organic mix layer 3210 (e.g., DUO™) is performed (
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[0066] The CB to PC formation is shown, wherein CB is offset from the metal gate 3020. The CA to TS formation is shown, wherein the CA formation is offset coupled to the TS formation 1710. Further, the CB formations are offset coupled to the gate metals 3020. The offset connections described above may provide for density, ability to pattern with a double-patterning scheme, and reduction in occurrence of short circuits or better yield. The processes described above provide for efficient cross-coupling of devices.
[0067] The processes above may be used to provide a cross coupled device exemplified by the stylized depiction provided in
[0068] The CA/CB stitching provided by embodiments herein connects to TS, which in turn, connects to the gate. Since the same TS cannot be used for other CA/CB stitched pairs, offsetting may be employed. The CB connection is offset and CB connects to selected M0 and M1 structures. The M1 structure goes down to M0, and vice versa. The M1 structure here slides over the gate because it is not connected to the gate. The M1 structure goes down to M0, CB. The CB structure goes down to the gate.
[0069] Embodiments herein provide many advantages. For example, the gate T-shape cap described above on
[0070] Other advantages of embodiments herein include the fact that the TS is borderless, thus, gate to contact shorts are reduced, while area of contact is increased. Further the top of the TS structure would be flush with the top of the gate cap. Further, since CB is self-aligned into M0, the PC pickup using CB structures is possible. Also, since the top of CA and M0 are flush, they are ready for pick up simultaneously by M1/V0.
[0071] Further advantages include the fact that TS pass-through is possible, which reduces the usage of C-shape M1 structures. This may improve yields since C-shape structures can cause process errors due to corner rounding and difficulties in controlling etch biases.
[0072] Embodiments provide for the possibility of CA/CB stitch. This can be used for landing V0 or to short gate to Source/Drain. Further, gate tie constructs to power rail and ground rails are made easier through M0 or CA/CB stitch. Also, CA flyover with respect to multiple gates is possible since CA is not borderless and the gates have protection from thick nitride caps.
[0073] Other advantages of embodiments herein include the fact that the CB connector construct may be formed using either long bar CB structures or long bar M0 structures. Further, using embodiments herein, a one-CPP (contacted polysilicon pitch) cross couple design is possible. Further, a TS pass-through may be also implemented.
[0074] Turning now to
[0075] The semiconductor device processing system 4410 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 4410 may be controlled by the processing controller 4420. The processing controller 4420 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.
[0076] The semiconductor device processing system 4410 may produce integrated circuits on a medium, such as silicon wafers. More particularly, the semiconductor device processing system 4410 produce integrated circuits having finFET devices that comprise gate fins that have a rounded head and/or a neck as described above.
[0077] The production of integrated circuits by the device processing system 4410 may be based upon the circuit designs provided by the integrated circuits design unit 4440. The processing system 4410 may provide processed integrated circuits/devices 4415 on a transport mechanism 4450, 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 4410 may comprise a plurality of processing steps, e.g., the 1.sup.st process step, the 2.sup.nd process set, etc., as described above.
[0078] In some embodiments, the items labeled “4415” may represent individual wafers, and in other embodiments, the items 4415 may represent a group of semiconductor wafers, e.g., a “lot” of semiconductor wafers. The integrated circuit or device 4415 may be a transistor, a capacitor, a resistor, a memory cell, a processor, and/or the like. In one embodiment, the device 4415 is a transistor and the dielectric layer is a gate insulation layer for the transistor.
[0079] The integrated circuit design unit 4440 of the system 4400 is capable of providing a circuit design that may be manufactured by the semiconductor processing system 4410. The integrated circuit design unit 4440 may receive various types of data including performance data, device specification, etc. Using such data, the design unit 4440 may provide various process definitions based on the data that includes performance data, device specification, etc. Based upon such details of the devices, the integrated circuit design unit 4440 may determine specifications of the finFETs that are to be manufactured using the processes described above. Based upon these specifications, the integrated circuit design unit 4440 may provide data for manufacturing a semiconductor device package described herein.
[0080] The system 4400 may be capable of performing analysis and manufacturing of various products involving various technologies. For example, the system 4400 may 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.
[0081] The particular embodiments disclosed above are illustrative only, as the invention 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 invention. Accordingly, the protection sought herein is as set forth in the claims below.