DETAILED ACTION
Notice of Pre-AIA or AIA Status
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Election/Restrictions
Applicant’s election without traverse of claims 1-12 in the reply filed on 06/05/2026 is acknowledged.
Claims 13-21 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected Group II invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on 06/05/2026.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1-2 and 10 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by US 2021/0202310 to Hsieh et al. (hereinafter Hsieh) (the reference US 2011/0017499 by Yang et al. (hereinafter Yang) is presented as evidence).
With respect to claim 1, Hsieh discloses a method of forming electrical interconnects (Hsieh, Figs. 7-12, ¶0008, ¶0033-¶0043), the method comprising:
forming a barrier layer (e.g., 140/142, TaN and Ru layers are interpreted as a barrier layer; note that Ta, TaN, Ru, and TaRuN materials are used as a barrier layer for Cu, Al, Wu interconnect structures, as evidenced by Yang, ¶0032) (Hsieh, Fig. 8, ¶0034-¶0035, ¶0037) within a substrate feature (e.g., the opening 130 within a dielectric layer 110 on a substrate 50);
forming a liner layer (e.g., 144 including cobalt (Co)) (Hsieh, Fig. 9, ¶0036-¶0037) on the barrier layer (e.g., 140/142); and
treating (e.g., hydrogen plasma process to form combined layer 148) (Hsieh, Fig. 10, ¶0038-¶0039) the liner layer (144) and the barrier layer (140/142) to form a treated composite (148),
wherein the barrier layer (140/142) is not densified before deposition of the liner layer (e.g., the liner layer 144 is formed over the ruthenium layer 142 without modifying the barrier layer 140/142).
Regarding claim 2, Hsieh discloses the method of claim 1. Further, Hsieh discloses the method, wherein treating the liner layer (e.g., 144) (Hsieh, Fig. 10, ¶0038-¶0039) and the barrier layer (e.g., 140/142) comprises exposing the liner layer (144) to a second plasma (e.g., hydrogen plasma) formed from a second plasma gas comprising hydrogen gas.
Regarding claim 10, Hsieh discloses the method of claim 1. Further, Hsieh discloses the method, further comprising depositing a metal fill (150) (Hsieh, Fig. 11, ¶0040-¶0042) on the treated composite (148) within the substrate feature.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-4, 6-10, and 12 are rejected under 35 U.S.C. 103 as being unpatentable over US 2015/0255333 to Lu et al. (hereinafter Lu) in view of Zhang et al. (US Patent No. 6,436,819, hereinafter Zhang).
With respect to claim 1, Lu discloses a method of forming electrical interconnects (Lu, Figs. 2A-2F, ¶0018-¶0054), the method comprising:
forming a barrier layer (e.g., 210, a lower layer of metallic tantalum (Ta) layer) (Lu, Figs. 2A-2B, ¶0020-¶0022) within a substrate feature (e.g., aperture 206 within a dielectric layer 204 on a substrate 202);
optionally treating the barrier layer with a first plasma (e.g., a pre-treatment plasma process to remove contaminants from the barrier layer 210) (Lu, Figs. 2A-2B, ¶0025-¶0028);
forming a liner layer (e.g., forming an upper layer of tantalum nitride (TaN) over the lower Ta layer, and further forming a liner layer 220 including a cobalt material) (Lu, Figs. 2B-2C, ¶0022-¶0023, ¶0031-¶0041) on the barrier layer (e.g., the lower Ta layer); and
treating (e.g., a pre-treatment plasma process to remove contaminants from the barrier layer and a post-treatment plasma process to remove contaminants from the cobalt layer 220) (Lu, Figs. 2B-2C, ¶0025-¶0028, ¶0042-¶0046) the liner layer and the barrier layer,
wherein the barrier layer (e.g., e.g., the treatment plasma process to remove contaminants does not densify the barrier layer 210) is not densified before deposition of the liner layer.
Further, Lu does not specifically disclose treating the liner layer and the barrier layer to form a treated composite.
However, Zhang teaches a method of forming a nitride/metal stack (Zhang, Figs. 5a-5e, Col. 3, lines 34-41; Col. 7, lines 61-67; Col. 8-10) by forming a nitride layer (e.g., 508) (Zhang, Fig. 5c, Col. 8, lines 1-37) upon a metal layer (506), and followed by treating the nitride layer and a portion of the metal layer in nitrogen/hydrogen containing plasma (e.g., 550) (Zhang, Fig. 5d, Col. 8, lines 37-67; Col. 9, lines 1-47) to change film composition of the barrier layer and the upper portion of the liner layer to form treated barrier/liner composite (509/507) (Zhang, Fig. 5e, Col. 8, lines 62-67; Col. 9, lines 1-47) including densified nitrated metal such that barrier/liner stack has improved properties such as enhanced adhesion, stronger barrier to interlayer diffusion and resistance to chemical attacks during subsequent processes.
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Lu by forming a barrier/liner stack treated with nitrogen/hydrogen containing plasma as taught by Zhang to have treating the liner layer and the barrier layer to form a treated composite, in order to provide a barrier/liner stack having improved properties such as enhanced adhesion, reduced interfacial stress, decreased resistivity, and stronger barrier to interlayer diffusion and resistance to chemical attacks during subsequent processes (Zhang, Col. 1, lines 61-67; Col. 2, lines 1-4; Col. 3, lines 34-57; Col. 8, lines 62-67; Col. 9, lines 1-48; Col. 10, lines 6-14).
Regarding claim 2, Lu in view of Zhang discloses the method of claim 1. Further, Lu discloses the method, wherein treating the liner layer (e.g., the upper layer of tantalum nitride (TaN) over the lower Ta layer, and the liner layer 220 including a cobalt material) (Lu, Figs. 2B-2C, ¶0022-¶0023, ¶0031-¶0041) and the barrier layer (e.g., the lower layer of tantalum) comprises exposing the liner layer to a second plasma (Lu, Figs. 2B-2C, ¶0042-¶0046) formed from a second plasma gas comprising hydrogen gas (Lu, ¶0045-¶0046).
Regarding claim 3, Lu in view of Zhang discloses the method of claim 2. Further, Lu discloses the method, wherein the second plasma gas further comprises a noble gas (e.g., argon) (Lu, ¶0045).
Regarding claim 4, Lu in view of Zhang discloses the method of claim 3. Further, Lu discloses the method, wherein the noble gas consists essentially of argon (Lu, ¶0045).
Regarding claim 6, Lu in view of Zhang discloses the method of claim 2. Further, Lu does not specifically disclose the method, wherein the liner layer is exposed to the second plasma at a pressure in a range of 0.1 mTorr to 1 Torr.
However, Zhang teaches forming the barrier/liner stack (Zhang, Figs. 5a-5e, Col. 3, lines 34-41; Col. 7, lines 61-67; Col. 8-10) by using a hydrogen/nitrogen N2/H2 plasma (Zhang, Figs. 5a-5e, Col. 10, lines 15-26), wherein the stack is exposed the N2/H2 plasma at a pressure in a range of 1 mTorr to 25 Torr, and the pressure condition depends on processing chamber.
The claimed range overlaps the rage of Zhang. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists (M.P.E.P. §2144.05).
Further, the prior art well recognizes that a processing chamber and plasma containing specific components are critical in forming the composite for the barrier/liner stack (e.g., Zhang, Figs. 5a-5e, Col. 10, lines 20-26). Thus, processing chamber and plasma containing specific components are art-recognized result-affecting variables/parameters. According to well established patent law precedent (M.P.E.P. § 2144.05), therefore, it would have been obvious to optimize (for example by routine experimentation) processing chamber and plasma containing specific components to achieve a pressure in a specific range of 0.1 mTorr to 1 Torr, to provide improved method of forming barrier/liner stack having improved properties such as enhanced adhesion, reduced interfacial stress, decreased resistivity, and stronger barrier to interlayer diffusion and resistance to chemical attacks during subsequent processes (Zhang, Col. 1, lines 61-67; Col. 2, lines 1-4; Col. 3, lines 34-57; Col. 8, lines 62-67; Col. 9, lines 1-48; Col. 10, lines 6-14).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Lu/Zhang by selecting specific processing chamber and optimizing plasma components as taught by Zhang to have the method, wherein the liner layer is exposed to the second plasma at a pressure in a range of 0.1 mTorr to 1 Torr, in order to provide a barrier/liner stack having improved properties such as enhanced adhesion, reduced interfacial stress, decreased resistivity, and stronger barrier to interlayer diffusion and resistance to chemical attacks during subsequent processes (Zhang, Col. 1, lines 61-67; Col. 2, lines 1-4; Col. 3, lines 34-57; Col. 8, lines 62-67; Col. 9, lines 1-48; Col. 10, lines 6-14).
Regarding claim 7, Lu in view of Zhang discloses the method of claim 1. Further, Lu does not specifically disclose the method, wherein the method lowers the resistivity of the treated composite as compared to the barrier layer and the liner layer without treatments.
However, Zhang teaches forming the barrier/liner stack (Zhang, Figs. 5a-5e, Col. 3, lines 34-41; Col. 7, lines 61-67; Col. 8-10) by using a hydrogen/nitrogen N2/H2 plasma (Zhang, Figs. 5a-5e, Col. 10, lines 15-26), wherein the presence of hydrogen in the plasma reduces content of chlorine in the liner layer (508) so as to reduce sheet resistance (Zhang, Figs. 5a-5e, Col. 10, lines 9-14).
The prior art well recognizes that the presence of hydrogen in plasma is critical in forming the barrier/liner stack having reduced resistivity of the treated composite (e.g., Zhang, Figs. 5a-5e, Col. 10, lines 9-14). Thus, the content of hydrogen in plasma is art-recognized result-affecting variables/parameter. According to well established patent law precedent (M.P.E.P. § 2144.05), therefore, it would have been obvious to optimize (for example by routine experimentation) the content of hydrogen in plasma to achieve reduced resistivity of the treated composite, to provide improved method of forming barrier/liner stack having improved properties such as enhanced adhesion, reduced interfacial stress, decreased resistivity, and stronger barrier to interlayer diffusion and resistance to chemical attacks during subsequent processes (Zhang, Col. 1, lines 61-67; Col. 2, lines 1-4; Col. 3, lines 34-57; Col. 8, lines 62-67; Col. 9, lines 1-48; Col. 10, lines 6-14).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Lu/Zhang by optimizing the content of hydrogen in plasma as taught by Zhang to have the method, wherein the method lowers the resistivity of the treated composite as compared to the barrier layer and the liner layer without treatments, in order to provide a barrier/liner stack having improved properties such as enhanced adhesion, reduced interfacial stress, decreased resistivity, and stronger barrier to interlayer diffusion and resistance to chemical attacks during subsequent processes (Zhang, Col. 1, lines 61-67; Col. 2, lines 1-4; Col. 3, lines 34-57; Col. 8, lines 62-67; Col. 9, lines 1-48; Col. 10, lines 6-14).
Regarding claim 8, Lu in view of Zhang discloses the method of claim 1. Further, Lu does not specifically disclose the method, wherein treating the liner layer and the barrier layer increases a grain size of the liner layer.
However, Zhang teaches forming the barrier/liner stack (Zhang, Figs. 5a-5e, Col. 3, lines 34-41; Col. 7, lines 61-67; Col. 8-10) by using a plasma over-treatment (Zhang, Figs. 5a-5e, Col. 9, lines 37-56) to enhance grain growth to provide treated composite layer (509/507) having better barrier charteristics due to reduced sheet resistance and increased film density (Zhang, Figs. 5a-5e, Col. 9, lines 52-56).
The prior art well recognizes that plasma over-treatment is critical in forming the barrier/liner stack having enhanced grain growth of the treated composite (e.g., Zhang, Figs. 5a-5e, Col. 9, lines 37-56). Thus, plasma over-treatment is art-recognized result-affecting variables/parameter. According to well established patent law precedent (M.P.E.P. § 2144.05), therefore, it would have been obvious to optimize (for example by routine experimentation) plasma over-treatment to achieve enhanced grain growth of the treated composite, to provide improved method of forming barrier/liner stack having improved properties such as enhanced adhesion, reduced interfacial stress, decreased resistivity, and stronger barrier to interlayer diffusion and resistance to chemical attacks during subsequent processes (Zhang, Col. 1, lines 61-67; Col. 2, lines 1-4; Col. 3, lines 34-57; Col. 8, lines 62-67; Col. 9, lines 1-48; Col. 10, lines 6-14).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Lu/Zhang by optimizing plasma over-treatment as taught by Zhang to have the method, wherein treating the liner layer and the barrier layer increases a grain size of the liner layer, in order to provide a barrier/liner stack having improved properties such as enhanced adhesion, reduced interfacial stress, decreased resistivity, and stronger barrier to interlayer diffusion and resistance to chemical attacks during subsequent processes (Zhang, Col. 1, lines 61-67; Col. 2, lines 1-4; Col. 3, lines 34-57; Col. 8, lines 62-67; Col. 9, lines 1-48; Col. 10, lines 6-14).
Regarding claim 9, Lu in view of Zhang discloses the method of claim 1. Further, Lu does not specifically disclose the method, wherein treating the liner layer and the barrier layer provides the treated composite with a thickness up to 3 A less than a cumulative thickness of the liner layer and the barrier layer before treatment.
However, Zhang teaches forming the barrier/liner stack (Zhang, Figs. 5a-5e, Col. 3, lines 34-41; Col. 7, lines 61-67; Col. 8-10) by using a plasma over-treatment (Zhang, Figs. 5a-5e, Col. 9, lines 37-56), wherein treating the liner layer (508) and the barrier layer (506) provides the treated composite (509/507) with a thickness at least to 40 Å less (e.g., 60 Å liner layer 508 is densified to result 20 Å thick layer after plasma treatment depending on specific conditions) (Zhang, Figs. 5a-5e, Col. 8, lines 54-67) than a cumulative thickness of the liner layer (508) and the barrier layer (506) before treatment.
The prior art well recognizes that densification of the barrier/liner stack depends on specific conditions of plasma treatment that is critical in forming the dense composite (e.g., Zhang, Figs. 5a-5e, Col. 8, lines 54-67). Thus, specific conditions of plasma treatment is art-recognized result-affecting variables/parameter. According to well established patent law precedent (M.P.E.P. § 2144.05), therefore, it would have been obvious to optimize (for example by routine experimentation) specific conditions of plasma treatment to achieve the treated composite with a thickness up to 3 A less than a cumulative thickness of the liner layer and the barrier layer before treatment, to provide improved method of forming barrier/liner stack having improved properties such as enhanced adhesion, reduced interfacial stress, decreased resistivity, and stronger barrier to interlayer diffusion and resistance to chemical attacks during subsequent processes (Zhang, Col. 1, lines 61-67; Col. 2, lines 1-4; Col. 3, lines 34-57; Col. 8, lines 62-67; Col. 9, lines 1-48; Col. 10, lines 6-14).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Lu/Zhang by optimizing specific conditions of plasma treatment of the barrier/liner stack as taught by Zhang to have the method, wherein treating the liner layer and the barrier layer provides the treated composite with a thickness up to 3 A less than a cumulative thickness of the liner layer and the barrier layer before treatment, in order to provide a barrier/liner stack having improved properties such as enhanced adhesion, reduced interfacial stress, decreased resistivity, and stronger barrier to interlayer diffusion and resistance to chemical attacks during subsequent processes (Zhang, Col. 1, lines 61-67; Col. 2, lines 1-4; Col. 3, lines 34-57; Col. 8, lines 62-67; Col. 9, lines 1-48; Col. 10, lines 6-14).
Regarding claim 10, Lu in view of Zhang discloses the method of claim 1. Further, Lu discloses the method, further comprising depositing a metal fill (e.g., bulk metal 240) (Lu, Figs. 2D, 2F, ¶0049-¶0052) within the substrate feature (206), but does not specifically disclose depositing a metal fill on the treated composite.
However, Zhang teaches forming the treated composite (509/507) (Zhang, Figs. 5a-5e, Col. 8, lines 62-67; Col. 9, lines 1-47) for the barrier/liner stack in a metallization scheme (Zhang, Figs. 5a-5e, Col. 1, lines 66-67; Col. 2, lines 1-4; Col. 3, lines 34-41; Col. 13, lines 65-67; Col. 14, lines 1-8) for sub-0.18 mm application.
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Lu/Zhang by forming a metallization scheme including the barrier/liner stack as taught by Zhang to have the method, further comprising a metal fill on the treated composite, in order to provide a barrier/liner stack having improved properties such as enhanced adhesion, reduced interfacial stress, decreased resistivity, and stronger barrier to interlayer diffusion and resistance to chemical attacks during subsequent processes (Zhang, Col. 1, lines 61-67; Col. 2, lines 1-4; Col. 3, lines 34-57; Col. 8, lines 62-67; Col. 9, lines 1-48; Col. 10, lines 6-14).
Regarding claim 12, Lu in view of Zhang discloses the method of claim 10. Further, Lu discloses the method, the metal fill (240) (Lu, Figs. 2D, 2F, ¶0050-¶0052) is deposited by PVD, but does not specifically disclose that the metal fill is deposited in the same chamber as treating the liner layer and the barrier layer.
However, Zhang teaches forming the barrier/liner stack (Zhang, Figs. 5a-5e, Col. 8, lines 39-67; Col. 9, lines 1-56) including composite layer by using plasma with different combination of process parameters (e.g., plasma treatment time, power, pressure, flow rates and so on) to modify the entire thickness of the liner layer (508) and a top portion of the barrier layer (506), wherein the process parameters depend on processing chambers used.
Further, the prior art well recognizes that a processing chamber and plasma process parameters are critical in forming the composite for the barrier/liner stack (e.g., Zhang, Figs. 5a-5e, Col. 8, lines 39-67; Col. 9, lines 1-56). Thus, a specific processing chamber and plasma process parameters are art-recognized result-affecting variables/parameters. According to well established patent law precedent (M.P.E.P. § 2144.05), therefore, it would have been obvious to optimize (for example by routine experimentation) processing chamber and plasma process parameters to select chamber such that the metal fill is deposited in the same chamber as treating the liner layer and the barrier layer, to provide improved method of forming barrier/liner stack having improved properties such as enhanced adhesion, reduced interfacial stress, decreased resistivity, and stronger barrier to interlayer diffusion and resistance to chemical attacks during subsequent processes (Zhang, Col. 1, lines 61-67; Col. 2, lines 1-4; Col. 3, lines 34-57; Col. 8, lines 62-67; Col. 9, lines 1-48; Col. 10, lines 6-14).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Lu/Zhang by selecting specific processing chamber and optimizing plasma process parameters as taught by Zhang to have the method, wherein the metal fill is deposited in the same chamber as treating the liner layer and the barrier layer, in order to provide a barrier/liner stack having improved properties such as enhanced adhesion, reduced interfacial stress, decreased resistivity, and stronger barrier to interlayer diffusion and resistance to chemical attacks during subsequent processes (Zhang, Col. 1, lines 61-67; Col. 2, lines 1-4; Col. 3, lines 34-57; Col. 8, lines 62-67; Col. 9, lines 1-48; Col. 10, lines 6-14).
Claims 3-4 are rejected under 35 U.S.C. 103 as being unpatentable over US 2021/0202310 to Hsieh in view of Lu (US 2015/0255333).
Regarding claims 3 and 4, Hsieh discloses the method of claim 2. Further, Hsieh does not specifically disclose that the second plasma gas further comprises a noble gas (as claimed in claim 3); wherein the noble gas consists essentially of argon (as claimed in claim 4).
However, Lu teaches the method, wherein second plasma treatment is performed on the cobalt layer (220) to remove contaminants, and the second plasma gas further comprises a noble gas (e.g., argon) (Lu, ¶0042-¶0045).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Hsieh by performing plasma treatment on the liner layer as taught by Lu to have the method, wherein the second plasma gas further comprises a noble gas (as claimed in claim 3); wherein the noble gas consists essentially of argon (as claimed in claim 4), in order to remove contaminants form the liner layer to facilitate subsequent deposition of metal fill (Lu, ¶0042-¶0045).
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over US 2015/0255333 to Lu in view of Zhang (US Patent No. 6,436,819) as applied to claim 2, and further in view of Colombeau et al. (US 2020/0261171, hereinafter Colombeau).
Regarding claim 5, Lu in view of Zhang discloses the method of claim 2. Further, Lu does not specifically disclose the method, wherein the second plasma is an inductively coupled RF plasma.
However, Colombeau teaches a method of densifying a liner layer (14) (Colombeau, Figs. 1, 4, ¶0004, ¶0006-¶0008, ¶0050, ¶0073-¶0075) by using a plasma treatment, wherein the processing system comprises a processing chamber (120) configured to implement an inductively coupled plasma (ICP) and to perform a plasma treatment to densify the liner layer (14). The plasma process comprises a power of RF power source in a rnage between 500 W and 5000W at a frequency range between 2 MHz and 160 MHz. The processing system of Colombeau is able to form complex devices at smaller dimensions while maintaining satisfactory performance of the devices of the integrated circuits (Colombeau, Figs. 1, 4, ¶0004).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Lu/Zhang by using processing system comprising a processing chamber to perform a plasma treatment as taught by Colombeau to have the method, wherein the second plasma is an inductively coupled RF plasma, in order to provide processing system able to form complex devices at smaller dimensions while maintaining satisfactory performance of the devices of the integrated circuits (Colombeau, ¶0004, ¶0006-¶0008, ¶0050, ¶0073).
Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over US 2021/0202310 to Hsieh in view of Colombeau (US 2020/0261171).
Regarding claim 5, Hsieh discloses the method of claim 2. Further, Hsieh does not specifically disclose the method, wherein the second plasma is an inductively coupled RF plasma.
However, Colombeau teaches a method of densifying a liner layer (14) (Colombeau, Figs. 1, 4, ¶0004, ¶0006-¶0008, ¶0050, ¶0073-¶0075) by using a plasma treatment, wherein the processing system comprises a processing chamber (120) configured to implement an inductively coupled plasma (ICP) and to perform a plasma treatment to densify the liner layer (14). The plasma process comprises a power of RF power source in a rnage between 500 W and 5000W at a frequency range between 2 MHz and 160 MHz. The processing system of Colombeau is able to form complex devices at smaller dimensions while maintaining satisfactory performance of the devices of the integrated circuits (Colombeau, Figs. 1, 4, ¶0004).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Hsieh by using processing system comprising a processing chamber to perform a plasma treatment as taught by Colombeau to have the method, wherein the second plasma is an inductively coupled RF plasma, in order to provide processing system able to form complex devices at smaller dimensions while maintaining satisfactory performance of the devices of the integrated circuits (Colombeau, ¶0004, ¶0006-¶0008, ¶0050, ¶0073).
Claims 6-9 and 12 are rejected under 35 U.S.C. 103 as being unpatentable over US 2021/0202310 to Hsieh in view of Zhang (US Patent No. 6,436,819).
Regarding claim 6, Hsieh discloses the method of claim 2. Further, Hsieh does not specifically disclose the method, wherein the liner layer is exposed to the second plasma at a pressure in a range of 0.1 mTorr to 1 Torr.
However, Zhang teaches forming the barrier/liner stack (Zhang, Figs. 5a-5e, Col. 3, lines 34-41; Col. 7, lines 61-67; Col. 8-10) by using a hydrogen/nitrogen N2/H2 plasma (Zhang, Figs. 5a-5e, Col. 10, lines 15-26), wherein the stack is exposed the N2/H2 plasma at a pressure in a range of 1 mTorr to 25 Torr, and the pressure condition depends on processing chamber.
The claimed range overlaps the rage of Zhang. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists (M.P.E.P. §2144.05).
Further, the prior art well recognizes that a processing chamber and plasma containing specific components are critical in forming the composite for the barrier/liner stack (e.g., Zhang, Figs. 5a-5e, Col. 10, lines 20-26). Thus, processing chamber and plasma containing specific components are art-recognized result-affecting variables/parameters. According to well established patent law precedent (M.P.E.P. § 2144.05), therefore, it would have been obvious to optimize (for example by routine experimentation) processing chamber and plasma containing specific components to achieve a pressure in a specific range of 0.1 mTorr to 1 Torr, to provide improved method of forming barrier/liner stack having improved properties such as enhanced adhesion, reduced interfacial stress, decreased resistivity, and stronger barrier to interlayer diffusion and resistance to chemical attacks during subsequent processes (Zhang, Col. 1, lines 61-67; Col. 2, lines 1-4; Col. 3, lines 34-57; Col. 8, lines 62-67; Col. 9, lines 1-48; Col. 10, lines 6-14).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Hsieh by selecting specific processing chamber and optimizing plasma components as taught by Zhang to have the method, wherein the liner layer is exposed to the second plasma at a pressure in a range of 0.1 mTorr to 1 Torr, in order to provide a barrier/liner stack having improved properties such as enhanced adhesion, reduced interfacial stress, decreased resistivity, and stronger barrier to interlayer diffusion and resistance to chemical attacks during subsequent processes (Zhang, Col. 1, lines 61-67; Col. 2, lines 1-4; Col. 3, lines 34-57; Col. 8, lines 62-67; Col. 9, lines 1-48; Col. 10, lines 6-14).
Regarding claim 7, Hsieh discloses the method of claim 1. Further, Hsieh does not specifically disclose the method, wherein the method lowers the resistivity of the treated composite as compared to the barrier layer and the liner layer without treatments.
However, Zhang teaches forming the barrier/liner stack (Zhang, Figs. 5a-5e, Col. 3, lines 34-41; Col. 7, lines 61-67; Col. 8-10) by using a hydrogen/nitrogen N2/H2 plasma (Zhang, Figs. 5a-5e, Col. 10, lines 15-26), wherein the presence of hydrogen in the plasma reduces content of chlorine in the liner layer (508) so as to reduce sheet resistance (Zhang, Figs. 5a-5e, Col. 10, lines 9-14).
The prior art well recognizes that the presence of hydrogen in plasma is critical in forming the barrier/liner stack having reduced resistivity of the treated composite (e.g., Zhang, Figs. 5a-5e, Col. 10, lines 9-14). Thus, the content of hydrogen in plasma is art-recognized result-affecting variables/parameter. According to well established patent law precedent (M.P.E.P. § 2144.05), therefore, it would have been obvious to optimize (for example by routine experimentation) the content of hydrogen in plasma to achieve reduced resistivity of the treated composite, to provide improved method of forming barrier/liner stack having improved properties such as enhanced adhesion, reduced interfacial stress, decreased resistivity, and stronger barrier to interlayer diffusion and resistance to chemical attacks during subsequent processes (Zhang, Col. 1, lines 61-67; Col. 2, lines 1-4; Col. 3, lines 34-57; Col. 8, lines 62-67; Col. 9, lines 1-48; Col. 10, lines 6-14).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Hsieh by optimizing the content of hydrogen in plasma as taught by Zhang to have the method, wherein the method lowers the resistivity of the treated composite as compared to the barrier layer and the liner layer without treatments, in order to provide a barrier/liner stack having improved properties such as enhanced adhesion, reduced interfacial stress, decreased resistivity, and stronger barrier to interlayer diffusion and resistance to chemical attacks during subsequent processes (Zhang, Col. 1, lines 61-67; Col. 2, lines 1-4; Col. 3, lines 34-57; Col. 8, lines 62-67; Col. 9, lines 1-48; Col. 10, lines 6-14).
Regarding claim 8, Hsieh discloses the method of claim 1. Further, Hsieh does not specifically disclose the method, wherein treating the liner layer and the barrier layer increases a grain size of the liner layer.
However, Zhang teaches forming the barrier/liner stack (Zhang, Figs. 5a-5e, Col. 3, lines 34-41; Col. 7, lines 61-67; Col. 8-10) by using a plasma over-treatment (Zhang, Figs. 5a-5e, Col. 9, lines 37-56) to enhance grain growth to provide treated composite layer (509/507) having better barrier charteristics due to reduced sheet resistance and increased film density (Zhang, Figs. 5a-5e, Col. 9, lines 52-56).
The prior art well recognizes that plasma over-treatment is critical in forming the barrier/liner stack having enhanced grain growth of the treated composite (e.g., Zhang, Figs. 5a-5e, Col. 9, lines 37-56). Thus, plasma over-treatment is art-recognized result-affecting variables/parameter. According to well established patent law precedent (M.P.E.P. § 2144.05), therefore, it would have been obvious to optimize (for example by routine experimentation) plasma over-treatment to achieve enhanced grain growth of the treated composite, to provide improved method of forming barrier/liner stack having improved properties such as enhanced adhesion, reduced interfacial stress, decreased resistivity, and stronger barrier to interlayer diffusion and resistance to chemical attacks during subsequent processes (Zhang, Col. 1, lines 61-67; Col. 2, lines 1-4; Col. 3, lines 34-57; Col. 8, lines 62-67; Col. 9, lines 1-48; Col. 10, lines 6-14).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Hsieh by optimizing plasma over-treatment as taught by Zhang to have the method, wherein treating the liner layer and the barrier layer increases a grain size of the liner layer, in order to provide a barrier/liner stack having improved properties such as enhanced adhesion, reduced interfacial stress, decreased resistivity, and stronger barrier to interlayer diffusion and resistance to chemical attacks during subsequent processes (Zhang, Col. 1, lines 61-67; Col. 2, lines 1-4; Col. 3, lines 34-57; Col. 8, lines 62-67; Col. 9, lines 1-48; Col. 10, lines 6-14).
Regarding claim 9, Hsieh discloses the method of claim 1. Further, Hsieh does not specifically disclose the method, wherein treating the liner layer and the barrier layer provides the treated composite with a thickness up to 3 A less than a cumulative thickness of the liner layer and the barrier layer before treatment.
However, Zhang teaches forming the barrier/liner stack (Zhang, Figs. 5a-5e, Col. 3, lines 34-41; Col. 7, lines 61-67; Col. 8-10) by using a plasma over-treatment (Zhang, Figs. 5a-5e, Col. 9, lines 37-56), wherein treating the liner layer (508) and the barrier layer (506) provides the treated composite (509/507) with a thickness at least to 40 Å less (e.g., 60 Å liner layer 508 is densified to result 20 Å thick layer after plasma treatment depending on specific conditions) (Zhang, Figs. 5a-5e, Col. 8, lines 54-67) than a cumulative thickness of the liner layer (508) and the barrier layer (506) before treatment.
The prior art well recognizes that densification of the barrier/liner stack depends on specific conditions of plasma treatment that is critical in forming the dense composite (e.g., Zhang, Figs. 5a-5e, Col. 8, lines 54-67). Thus, specific conditions of plasma treatment is art-recognized result-affecting variables/parameter. According to well established patent law precedent (M.P.E.P. § 2144.05), therefore, it would have been obvious to optimize (for example by routine experimentation) specific conditions of plasma treatment to achieve the treated composite with a thickness up to 3 A less than a cumulative thickness of the liner layer and the barrier layer before treatment, to provide improved method of forming barrier/liner stack having improved properties such as enhanced adhesion, reduced interfacial stress, decreased resistivity, and stronger barrier to interlayer diffusion and resistance to chemical attacks during subsequent processes (Zhang, Col. 1, lines 61-67; Col. 2, lines 1-4; Col. 3, lines 34-57; Col. 8, lines 62-67; Col. 9, lines 1-48; Col. 10, lines 6-14).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Hsieh by optimizing specific conditions of plasma treatment of the barrier/liner stack as taught by Zhang to have the method, wherein treating the liner layer and the barrier layer provides the treated composite with a thickness up to 3 A less than a cumulative thickness of the liner layer and the barrier layer before treatment, in order to provide a barrier/liner stack having improved properties such as enhanced adhesion, reduced interfacial stress, decreased resistivity, and stronger barrier to interlayer diffusion and resistance to chemical attacks during subsequent processes (Zhang, Col. 1, lines 61-67; Col. 2, lines 1-4; Col. 3, lines 34-57; Col. 8, lines 62-67; Col. 9, lines 1-48; Col. 10, lines 6-14).
Regarding claim 12, Hsieh discloses the method of claim 10. Further, Hsieh discloses the method, the metal fill (240) (Lu, Figs. 2D, 2F, ¶0050-¶0052) is deposited by PVD, but does not specifically disclose that the metal fill is deposited in the same chamber as treating the liner layer and the barrier layer.
However, Zhang teaches forming the barrier/liner stack (Zhang, Figs. 5a-5e, Col. 8, lines 39-67; Col. 9, lines 1-56) including composite layer by using plasma with different combination of process parameters (e.g., plasma treatment time, power, pressure, flow rates and so on) to modify the entire thickness of the liner layer (508) and a top portion of the barrier layer (506), wherein the process parameters depend on processing chambers used.
Further, the prior art well recognizes that a processing chamber and plasma process parameters are critical in forming the composite for the barrier/liner stack (e.g., Zhang, Figs. 5a-5e, Col. 8, lines 39-67; Col. 9, lines 1-56). Thus, a specific processing chamber and plasma process parameters are art-recognized result-affecting variables/parameters. According to well established patent law precedent (M.P.E.P. § 2144.05), therefore, it would have been obvious to optimize (for example by routine experimentation) processing chamber and plasma process parameters to select chamber such that the metal fill is deposited in the same chamber as treating the liner layer and the barrier layer, to provide improved method of forming barrier/liner stack having improved properties such as enhanced adhesion, reduced interfacial stress, decreased resistivity, and stronger barrier to interlayer diffusion and resistance to chemical attacks during subsequent processes (Zhang, Col. 1, lines 61-67; Col. 2, lines 1-4; Col. 3, lines 34-57; Col. 8, lines 62-67; Col. 9, lines 1-48; Col. 10, lines 6-14).
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Hsieh by selecting specific processing chamber and optimizing plasma process parameters as taught by Zhang to have the method, wherein the metal fill is deposited in the same chamber as treating the liner layer and the barrier layer, in order to provide a barrier/liner stack having improved properties such as enhanced adhesion, reduced interfacial stress, decreased resistivity, and stronger barrier to interlayer diffusion and resistance to chemical attacks during subsequent processes (Zhang, Col. 1, lines 61-67; Col. 2, lines 1-4; Col. 3, lines 34-57; Col. 8, lines 62-67; Col. 9, lines 1-48; Col. 10, lines 6-14).
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over US 2015/0255333 to Lu in view of Zhang (US Patent No. 6,436,819) as applied to claim 10, and further in view of Jiang et al. (US 2021/0111067, hereinafter Jiang).
Regarding claim 11, Lu in view of Zhang discloses the method of claim 10. Further, Lu does not specifically disclose the method, wherein the metal fill is free of substantial voids.
However, Jiang teaches a method of forming an interconnect structure (Jiang, Fig. 8, ¶0007, ¶0088-¶0109) comprising a metal fill (e.g., a gap filling layer 708) (Jiang, Fig. 8, ¶0095, ¶0098, ¶0104-¶0109) and performing a plasma treatment process to densify a portion of the metal fill (e.g., a gap filling layer 708) so as drive out the defects such as voids, air, and impurities from the metal fill (e.g., a gap filling layer 708), and further performing post-annealing process to provide the metal fill (708) in the opening (850) substantially void free with high gap filling capability, and having an enhanced film structure with high purity, large grain structure, less grain boundaries with smooth surface roughness, which provides a relatively robust film structure having higher film density and low film resistivity.
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Lu/Zhang by performing a plasma treatment process and post-annealing process on the metla fill as taught by Jiang to have the method, wherein the metal fill is free of substantial voids, in order to provide interconnect structure with high gap filling capability, high purity, large grain structure, less grain boundaries with smooth surface roughness, which provides a relatively robust film structure having higher film density and low film resistivity (Jiang, ¶0007, ¶0098, ¶0104, ¶0109).
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over US 2021/0202310 to Hsieh in view of Jiang (US 2021/0111067).
Regarding claim 11, Hsieh discloses the method of claim 10. Further, Hsieh does not specifically disclose the method, wherein the metal fill is free of substantial voids.
However, Jiang teaches a method of forming an interconnect structure (Jiang, Fig. 8, ¶0007, ¶0088-¶0109) comprising a metal fill (e.g., a gap filling layer 708) (Jiang, Fig. 8, ¶0095, ¶0098, ¶0104-¶0109) and performing a plasma treatment process to densify a portion of the metal fill (e.g., a gap filling layer 708) so as drive out the defects such as voids, air, and impurities from the metal fill (e.g., a gap filling layer 708), and further performing post-annealing process to provide the metal fill (708) in the opening (850) substantially void free with high gap filling capability, and having an enhanced film structure with high purity, large grain structure, less grain boundaries with smooth surface roughness, which provides a relatively robust film structure having higher film density and low film resistivity.
It would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify the method of Hsieh by performing a plasma treatment process and post-annealing process on the metla fill as taught by Jiang to have the method, wherein the metal fill is free of substantial voids, in order to provide interconnect structure with high gap filling capability, high purity, large grain structure, less grain boundaries with smooth surface roughness, which provides a relatively robust film structure having higher film density and low film resistivity (Jiang, ¶0007, ¶0098, ¶0104, ¶0109).
Conclusion
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/NATALIA A GONDARENKO/Primary Examiner, Art Unit 2891
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