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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 8/19/2026 has been entered.
Status of the Application
Acknowledgement is made of the amendment received on 8/19/2026. Claims 1-2, 4-11, and 13-19 are pending in this application. Claims 1, 14, and 16-19 are amended.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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 1-2, 11, 14, and 17-18 are rejected under 35 U.S.C. 103 as being unpatentable over Mevellec et al. (WO 2020/161256; hereinafter ‘Mevellec’) in view of Liu (US 2020/0091164), and RELIGIEUX et al. (US 2018/0363158; hereinafter ‘RELIGIEUX’).
Regarding claim 1, Mevellec teaches a process for fabricating a semiconductor device (p.13, lines 30-32), said process comprising the steps (the electrochemical process, p.9, line 25-p.10, line 4) of
a) bringing a first surface of a metal layer into contact with an electrolyte (by bringing the first (conductive) surface of a metallic seed layer with an electrolyte, p.5, lines 4-5; p.7, lines 2-4; p.10, lines 5-6), wherein the electrolyte comprises copper (II) ions, dopant metal ions to electrodeposit a copper-dopant metal alloy (the electrolyte for electrodeposition of a Cu alloy comprises Cu II ions and metal ions selected from Mn II ions or Zn II ions, p.5, lines 4-8, 10);
b) polarizing (polarizing the first surface in ramp mode, galvano-static mode, and galvano-pulsed mode, p.9, line 30; p.11, lines 14-15) said first surface for a time sufficient to cover it with the copper-dopant metal alloy (for a period of time sufficient to carry out conformal and complete filling with the alloy of Cu-Mn or Cu-Zn, p.9, lines 30-33), and
c) annealing the alloy to cause it to separate (annealing the alloy deposit of Cu-Mn or Cu-Zn forming two layers, p.12, lines 20-23) and form a first layer of copper and a second layer comprising the dopant metal and/or an oxide thereof (form the first layer comprising essentially Cu, and the second layer comprising essentially Mn or Zn),
wherein the dopant metal is selected from the group consisting of manganese and zinc (the second metal is selected from Mn or Zn, p.5, lines 5-6).
Mevellec does not teach that the semiconductor device is a 3D-NAND flash memory.
Liu teaches a process (FIG. 3E, [0012]) for fabricating a 3D-NAND flash memory (3D memory device is a NAND flash memory device, [0031]), including formation of conductive interconnect structures and bit lines using electroplating/electrodeposition techniques [0059-0060].
As taught by Liu, one of ordinary skill in the art would utilize and modify the above teaching into Mevellec to obtain and achieve the process for fabricating the 3D-NAND flash memory as claimed, because electroplating facilitates conductive filling of openings in the vertically stacked interconnect structures of a 3D NAND memory device [0031, 0060].
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ the teaching as taught by Liu in combination with Mevellec due to the above reason.
Mevellec in view of Liu does not teach that the electrolyte comprises a tetra-alkylammonium salt and an aliphatic polyamine having from 2 to 4 amino groups to electrodeposit a copper-dopant metal alloy, wherein the electrolyte has a pH between 6.0 and 10.0.
RELIGIEUX teaches a process for electrodeposition (electrodeposition using copper (II), [0115])
wherein the electrolyte comprises a tetra-alkylammonium salt and an aliphatic polyamine having from 2 to 4 amino groups (an electrodeposition solution corresponding to the claimed electrolyte comprises a tetra-ethyl-ammonium hydroxide and ethylenediamine having two amino groups, [0121, 0125]),
wherein the electrolyte has a pH between 6.0 and 10.0 (the electrolyte has a pH of 9.2, [0125]).
As taught by RELIGIEUX, one of ordinary skill in the art would utilize and modify the above teaching into Mevellec in view of Liu to obtain and achieve the process comprising the electrolyte comprising a tetra-alkylammonium salt and an aliphatic polyamine having from 2 to 4 amino groups to electrodeposit a copper-dopant metal alloy, wherein the electrolyte has a pH between 6.0 and 10.0 as claimed, because ethylenediamine improves copper filling performance [0135, 0138] and tetraethylammonium hydroxide adjusts the electrolyte pH [0158-0159], thereby providing efficient copper electrodeposition and filling [0017].
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ the teaching as taught by RELIGIEUX in combination with Mevellec in view of Liu due to the above reason.
Regarding claim 2, Mevellec in view Liu and RELIGIEUX teaches the process as claimed in claim 1, Mevellec in view of RELIGIEUX does not teach the process wherein the first layer of copper forms a copper bit line of the 3D-NAND flash memory.
Liu teaches the process wherein the first layer of copper forms a copper bit line of the 3D-NAND flash memory (330 is the bit line of the 3D-NAND flash memory and includes Cu, [0059-0060]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ and modify the teachings of Liu to obtain and achieve the process wherein the first layer of copper forms a copper bit line of the 3D-NAND flash memory as claimed, because copper is a well-known material and widely used as a bit line in the art. Further, it has been held to be within the general skill of a worker in the art to select a known material on the basis of its suitability for the intended used a matter of obvious design choice. In re Leshin, 277 F.2d 197, 125 USPQ 416 (CCPA 1960).
Regarding claim 11, Mevellec in view of Liu and RELIGIEUX teaches the process as claimed in claim 1, wherein the metal layer is a trench-filling copper deposit, and the step of electrodepositing the copper-dopant metal alloy is performed for a time sufficient to cover the trench-filling copper deposit, in order to form an alloy deposit (Mevellec: the electrodeposition step is stopped when the alloy deposit covers the flat surface of the substrate, which indicates that the cavities have been completely filled with the alloy, p.12, lines 6-9).
Although, Mevellec in view of Liu and RELIGIEUX does not explicitly teach the process wherein the first copper layer formed as a result of the annealing step being subsequently polished in a third chemical-mechanical polishing step.
Mevellec, however, provides that the cavities are obtained by implementation of a damascene process, which involves filling metal into trenches or vias, forming an overburden metal layer, and planarizing the surface by CMP (p.10, lines 18-19).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ and modify the teachings of Mevellec to obtain and achieve the process, wherein the second surface of the metal layer in contact with the conducting area being made of a contact metal selected from tungsten, molybdenum, cobalt and ruthenium as claimed, because CMP is part of the damascene process, as planarization of the overfilled metal layers is a necessary step to complete the interconnect formation.
Regarding claim 14, Mevellec in view of Liu and RELIGIEUX teaches the process as claimed in claim 1, wherein the electrolyte comprises a concentration of copper (II) ions between 1 mM and 12 mM, wherein the copper (II) ions are substantially in the form of complexes (Mevellec: the concentration of Cu (II) ions is from 15.74 mM to 78.68 mM, p.2, line 31).
Regarding claim 17, Mevellec in view of Liu and RELIGIEUX teaches the process as claimed in claim 1, Mevellec in view of Liu does not teach the process wherein the aliphatic polyamines having 2 to 4 amino groups in a molar concentration such that the ratio between the molar concentration of complexing agent and the molar concentration of copper (II) ions ranges from 1:1 and 3:1.
RELIGIEUX teaches the process wherein the aliphatic polyamines having 2 to 4 amino groups in a molar concentration such that the ratio between the molar concentration of complexing agent and the molar concentration of copper (II) ions ranges from 1:1 and 3:1 (the complexing agent is selected from ethylenediamine and the ratio of the molar concentration of the complexing agent to the molar concentration of copper II ions ranges from 0.15 to 6, [0033, 0045-0046]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ and modify the teachings of RELIGIEUX to obtain and achieve the process wherein the aliphatic polyamines having 2 to 4 amino groups in a molar concentration such that the ratio between the molar concentration of complexing agent and the molar concentration of copper (II) ions ranges from 1:1 and 3:1 as claimed, because it has been held that where the criticality of the claimed range is not shown and the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. MPEP §2144.05.
Regarding claim 18, Mevellec teaches a process for fabricating a semiconductor device (p.13, lines 30-32), said process comprising the steps (the electrochemical process, p.9, line 25-p.10, line 4) of
a) bringing a first surface of a metal layer into contact with an electrolyte (by bringing the first (conductive) surface of a metallic seed layer with an electrolyte, p.5, lines 4-5; p.7, lines 2-4; p.10, lines 5-6), wherein the electrolyte comprises copper (II) ions, dopant metal ions to electrodeposit a copper-dopant metal alloy (the electrolyte for electrodeposition of a Cu alloy comprises Cu II ions and metal ions selected from Mn II ions or Zn II ions, p.5, lines 4-8, 10);
b) polarizing (polarizing the first surface in ramp mode, galvano-static mode, and galvano-pulsed mode, p.9, line 30; p.11, lines 14-15) said first surface for a time sufficient to cover it with the copper-dopant metal alloy (for a period of time sufficient to carry out conformal and complete filling with the alloy of Cu-Mn or Cu-Zn, p.9, lines 30-33), and
c) annealing the alloy to cause it to separate (annealing the alloy deposit of Cu-Mn or Cu-Zn forming two layers, p.12, lines 20-23) and form a first layer of copper and a second layer comprising the dopant metal and/or an oxide thereof (form the first layer comprising essentially Cu, and the second layer comprising essentially Mn or Zn),
wherein the dopant metal is selected from the group consisting of manganese and zinc (the second metal is selected from Mn or Zn, p.5, lines 5-6);
wherein the electrolyte comprises a concentration of copper (II) ions between 1 mM and 120 mM, wherein the copper (II) ions are substantially in the form of complexes (copper II ions in a concentration corresponding to approximately 16 mM to 79 mM, based on a Cu 2+ concentration of 1 g/L to 5 g/L, p.2, line 31).
Mevellec does not teach that the semiconductor device is a 3D-NAND flash memory.
Liu teaches a process (FIG. 3E, [0012]) for fabricating a 3D-NAND flash memory (3D memory device is a NAND flash memory device, [0031]), including formation of conductive interconnect structures and bit lines using electroplating/electrodeposition techniques [0059-0060].
As taught by Liu, one of ordinary skill in the art would utilize and modify the above teaching into Mevellec to obtain and achieve the process for fabricating the 3D-NAND flash memory as claimed, because electroplating facilitates conductive filling of openings in the vertically stacked interconnect structures of a 3D NAND memory device [0031, 0060].
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ the teaching as taught by Liu in combination with Mevellec due to the above reason.
Mevellec in view of Liu does not teach that the electrolyte comprises a tetra-alkylammonium salt and an aliphatic polyamine having from 2 to 4 amino groups to electrodeposit a copper-dopant metal alloy, wherein the electrolyte has a pH between 6.0 and 10.0.
RELIGIEUX teaches a process for electrodeposition (electrodeposition using copper (II), [0115])
wherein the electrolyte comprises a tetra-alkylammonium salt and an aliphatic polyamine having from 2 to 4 amino groups (an electrodeposition solution corresponding to the claimed electrolyte comprises a tetra-ethyl-ammonium hydroxide and ethylenediamine having two amino groups, [0121, 0125]),
wherein the electrolyte has a pH between 6.0 and 10.0 (the electrolyte has a pH of 9.2, [0125]).
As taught by RELIGIEUX, one of ordinary skill in the art would utilize and modify the above teaching into Mevellec in view of Liu to obtain and achieve the process comprising the electrolyte comprising a tetra-alkylammonium salt and an aliphatic polyamine having from 2 to 4 amino groups to electrodeposit a copper-dopant metal alloy, wherein the electrolyte has a pH between 6.0 and 10.0 as claimed, because ethylenediamine improves copper filling performance [0135, 0138] and tetraethylammonium hydroxide adjusts the electrolyte pH [0158-0159], thereby providing efficient copper electrodeposition and filling [0017].
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ the teaching as taught by RELIGIEUX in combination with Mevellec in view of Liu due to the above reason.
Claims 4-10 are rejected under 35 U.S.C. 103 as being unpatentable over Mevellec (WO 2020/161256) in view of Liu (US 2020/0091164) and RELIGIEUX (US 2018/0363158) as applied to claim 1 above, and further in view of Kim et al. (US 2012/0012465; hereinafter ‘Kim’).
Regarding claim 4, Mevellec in view Liu and RELIGIEUX teaches the process as claimed in claim 1,
wherein the metal layer comprises a second surface (Mevellec: the metallic seed layer comprises a second surface, p.10, lines 5-7)
which is in contact with an insulating area (the second surface in contact with an insulating area comprising silicon dioxide), said
insulating area being made of a dielectric material (the insulating area is made of a dielectric material).
Mevellec in view of RELIGIEUX does not teach the process, wherein the second surface of the metal layer in contact with the conducting area being made of a contact metal selected from the group consisting of tungsten, molybdenum, cobalt and ruthenium, and the contact metal being intended to connect a copper bit line and a polysilicon channel of the 3D-NAND flash memory.
Liu teaches the process, wherein the contact metal (328, [0059]) being intended to connect (shown in FIG. 3) a copper bit line (33, which include Cu, [0060]) and a polysilicon channel of the 3D-NAND flash memory (202 is part of 200 including polysilicon, and 200 in FIG. 2 corresponds to 326 in FIG. 3E, FIG. 2, [0034]).
Although, Liu does not explicitly teach the process, wherein the second surface of the metal layer in contact with the conducting area being made of a contact metal selected from the group consisting of tungsten, molybdenum, cobalt and ruthenium.
Liu, however, recognizes that the contact metal for interconnect lines and via contacts includes conductive materials such as tungsten and cobalt [0029].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ and modify the teachings of Liu to obtain and achieve the process, wherein the second surface of the metal layer in contact with the conducting area being made of a contact metal selected from the group consisting of tungsten, molybdenum, cobalt and ruthenium, and the contact metal being intended to connect a copper bit line and a polysilicon channel of the 3D-NAND flash memory as claimed, because tungsten and cobalt are well-known materials that are widely used as the contact metal and copper and polysilicon are well-known materials that are widely used as the bit line and the channel in the 3D-NAND flash memory. Further, it has been held to be within the general skill of a worker in the art to select a known material on the basis of its suitability for the intended used a matter of obvious design choice. In re Leshin, 277 F.2d 197, 125 USPQ 416 (CCPA 1960).
Mevellec in view of Liu and RELIGIEUX does not teach the process, wherein the metal layer comprises a second surface which is in contact with a mixed surface comprising both an insulating area and a conducting area, said insulating area being made of a dielectric material and said conducting area being made of a contact metal.
Kim teaches a process (FIG. 1, [0015]), wherein the metal layer (222 functions as a single seed layer, FIGS. 2 and 3A, [0020-0021]) comprises a second surface (the outer surface of 222)
which is in contact with a mixed surface (the outer surface of 222 is in contact with 210 and 208, [0021]) comprising both an insulating area (210 comprising an insulating area by 212, [0016]) and a conducting area (208 comprising a conductive area by 220), said
insulating area being made of a dielectric material (212 includes a dielectric material) and said
conducting area being made of a contact metal (220 includes a conductive material).
As taught by Kim, one of ordinary skill in the art would utilize and modify the above teaching into Mevellec in view of Liu and RELIGIEUX to obtain and achieve the process, wherein the metal layer comprises a second surface which is in contact with a mixed surface comprising both an insulating area and a conducting area, said insulating area being made of a dielectric material and said conducting area being made of a contact metal as claimed, because the seed layer contacts both a dielectric and a metal area, creating a potential difference at their interface, which acts as an electrical entry point where electrodeposition initiates to ensure electrical continuity and void-free bottom-up fill [0020, 0028].
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ the teaching as taught by Kim in combination with Mevellec in view of Liu and RELIGIEUX due to the above reason.
Regarding claim 5, Mevellec in view of Liu, RELIGIEUX, and Kim teaches the process as claimed in claim 4, Mevellec in view of Liu and RELIGIEUX does not teach the process wherein during the step of annealing the alloy the dopant metal migrates to the mixed surface, and in that the second layer comprising the dopant metal and/or an oxide thereof covers at least the insulating area of the mixed surface.
Kim teaches the process wherein during the step of annealing the alloy (annealing 222, FIG. 2, [0027])
the dopant metal migrates to the mixed surface (Mn migrates to the outer surface of 222), and
in that the second layer comprising the dopant metal and/or an oxide thereof covers at least the insulating area of the mixed surface (the oxide layer comprising Mn covers 210).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ and modify the teachings of Kim to obtain and achieve the process wherein during the step of annealing the alloy the dopant metal migrates to the mixed surface, and in that the second layer comprising the dopant metal and/or an oxide thereof covers at least the insulating area of the mixed surface as claimed, because Mn having a strong affinity for oxygen reacts with available oxygen contained in the dielectric material to form a oxide layer at the interface [0027].
Regarding claim 6, Mevellec in view of Liu, RELIGIEUX, and Kim teaches the process as claimed in claim 5, Mevellec in view of Liu and RELIGIEUX does not teach the process wherein the second layer comprises an oxide of the dopant metal and functions as a copper diffusion barrier.
Kim teaches the process wherein the second layer comprises an oxide of the dopant metal and functions as a copper diffusion barrier (the oxide layer comprises Mn and function as a Cu diffusion barrier, [0027]).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ and modify the teachings of Kim to obtain and achieve the process wherein the second layer comprises an oxide of the dopant metal and functions as a copper diffusion barrier as claimed, because forming a barrier layer on the opposite surface of the seed layer allows a thinner and lower-resistance barrier/seed structure, thereby improving device performance and process scalability for sub-22 nm nodes [0029].
Regarding claim 7, Mevellec in view of Liu, RELIGIEUX, and Kim teaches the process as claimed in claim 4, wherein the metal layer is a metal seed layer selected from the group consisting of copper, a copper alloy, and tantalum (Mevellec: the metallic seed layer selected from the group consisting of copper, copper alloy, and tantalum, p.10, lines 7-9), said seed layer having been deposited in contact with the mixed surface of an insulating area and a conducting area, in a step prior to the first electrodeposition step (prior to electrodeposition, the metallic seed layer is already formed to provide a conductive surface for the subsequent electrodeposition process, p.7, lines 2-4).
Regarding claim 8, Mevellec in view of Liu, RELIGIEUX, and Kim teaches the process as claimed in claim 7, but Mevellec in view of Liu and RELIGIEUX does not teach the process wherein a portion of the firs surface of the metal seed layer is concave, defining a hollow delimited by the walls and bottom of a trench.
Kim teaches the process wherein a portion of the firs surface of the metal seed layer is concave (the inner surface of 222, FIG. 2, [0020]), defining a hollow delimited by the walls and bottom of a trench (shown in FIG. 2).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ and modify the teachings of Kim to obtain and achieve the process wherein a portion of the firs surface of the metal seed layer is concave, defining a hollow delimited by the walls and bottom of a trench as claimed, because a concave-shaped seed layer is advantageous for vertical interconnect growth , as it helps prevent void formation and ensures a continuous conductive path [0017].
Regarding claim 9, Mevellec in view of Liu, RELIGIEUX, and Kim teaches the process as claimed in claim 8, but does not explicitly teach the process wherein the trench hollow has an average width at the opening ranging from 15 nm to 700 nm and an average depth ranging from 30 nm to 500 nm.
Kim, however, provides that as the device nodes approach dimensions of approximately 22 nm, the interconnect trench exhibits a height-to-width aspect ratio of at least about 5:1. Accordingly, it would have been understood that the trench opening has a width of about 22 nm and a depth of approximately 110 nm [0003, 0017].
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ and modify the teachings of Kim to obtain and achieve the process wherein the trench hollow has an average width at the opening ranging from 15 nm to 700 nm and an average depth ranging from 30 nm to 500 nm as claimed, because it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or working range involves only routine skill in the art. In re Alter, 105 USPQ 233.
Regarding claim 10, Mevellec in view of Liu, RELIGIEUX, and Kim teaches the process as claimed in claim 8, wherein the first step of electrodepositing the copper-dopant metal alloy is performed for a time sufficient to fill the hollow with said alloy (Mevellec: the electrodeposition step is stopped when the alloy deposit covers the flat surface of the substrate, which indicates that the cavities have been completely filled with the alloy, p.9, lines 30-33).
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Mevellec (WO 2020/161256) in view of Liu (US 2020/0091164) and RELIGIEUX (US 2018/0363158) as applied to claim 1 above, and further in view of Joi et al. (Journal of The Electrochemical Society, 160 (12) D3145-D3148, 2013; hereinafter ‘Joi’).
Regarding claim 13, Mevellec in view of Liu and RELIGIEUX teaches the process as claimed in claim 1, but does not teach the process wherein the electrolyte comprising copper (II) ions and dopant metal ions has a pH between 6.5 and 7.5.
Joi teaches a process (Experimental) wherein the electrolyte comprising copper (II) ions and dopant metal ions has a pH between 6.5 and 7.5 (the electrolyte of Cu-Mn electrodeposition has a 6.5 pH).
As taught by Joi, one of ordinary skill in the art would utilize and modify the above teaching into Mevellec in view of Liu and RELIGIEUX to obtain and achieve the process wherein the electrolyte comprising copper (II) ions and dopant metal ions has a pH between 6.5 and 7.5 as claimed, because it has been held that where the criticality of the claimed range is not shown and the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. MPEP §2144.05.
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ the teaching as taught by Joi in combination with Mevellec in view of Liu and RELIGIEUX due to the above reason.
Claims 15-16 are rejected under 35 U.S.C. 103 as being unpatentable over Mevellec (WO 2020/161256) in view of Liu (US 2020/0091164) and RELIGIEUX (US 2018/0363158) as applied to claim 1 above, and further in view of Senna et al. (Journal of Applied Electrochemistry 33: 1155–1161, 2003; hereinafter ‘Senna’).
Regarding claim 15, Mevellec in view of Liu and RELIGIEUX teaches the process as claimed in claim 1, but does not teach the process wherein the electrolyte comprising copper (II) ions and dopant metal ions is substantially free of chloride ions.
Senna teaches a process (2.2. Alloy electrodeposition experiments) wherein the electrolyte comprising copper (II) ions and dopant metal ions is substantially free of chloride ions (the electrolyte of Cu-Zn alloy is free of chloride ions, 2.2. Alloy electrodeposition experiments).
As taught by Senna, one of ordinary skill in the art would utilize and modify the above teaching into Mevellec in view of Liu and RELIGIEUX to obtain and achieve the process wherein the electrolyte comprising copper (II) ions and dopant metal ions is substantially free of chloride ions as claimed, because pyrophosphate serves as a complexing and buffering agent that replaces the functions of chloride ions by stabilizing Cu and Zn ions and enabling their uniform co-deposition (3.2.1. Chemical composition of the coatings).
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ the teaching as taught by Senna in combination with Mevellec in view of Liu and RELIGIEUX due to the above reason.
Regarding claim 16, Mevellec in view of Liu and RELIGIEUX teaches the process as claimed in claim 1, but does not teach the process wherein the electrolyte further comprises a sulfur salt of copper (II) ions.
Senna teaches a process (2.2. Alloy electrodeposition experiments) wherein the electrolyte further comprises a sulfur salt of copper (II) ions (the electrolyte of Cu-Zn alloy is further comprising CuSO4, Table 1).
As taught by Senna, one of ordinary skill in the art would utilize and modify the above teaching into Mevellec in view of Liu and RELIGIEUX to obtain and achieve the process wherein the electrolyte further comprises a sulfur salt of copper (II) ions as claimed, because CuSO4 is a known material and widely used as a source of copper ions in electroplating electrolyte. Further, it has been held to be within the general skill of a worker in the art to select a known material on the basis of its suitability for the intended used a matter of obvious design choice. In re Leshin, 277 F.2d 197, 125 USPQ 416 (CCPA 1960).
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ the teaching as taught by Senna in combination with Mevellec in view of Liu and RELIGIEUX due to the above reason.
Claim 19 is rejected under 35 U.S.C. 103 as being unpatentable over Mevellec (WO 2020/161256) in view of Liu (US 2020/0091164), RELIGIEUX (US 2018/0363158), and Kim et al. (US 2018/0286874; hereinafter ‘Kim874’).
Regarding claim 19, Mevellec teaches a process for fabricating a semiconductor device (p.13, lines 30-32), said process comprising the steps (the electrochemical process, p.9, line 25-p.10, line 4) of
a) bringing a first surface of a metal layer into contact with an electrolyte (by bringing the first (conductive) surface of a metallic seed layer with an electrolyte, p.5, lines 4-5; p.7, lines 2-4; p.10, lines 5-6), wherein the electrolyte comprises copper (II) ions, dopant metal ions to electrodeposit a copper-dopant metal alloy (the electrolyte for electrodeposition of a Cu alloy comprises Cu II ions and metal ions selected from Mn II ions or Zn II ions, p.5, lines 4-8, 10);
b) polarizing (polarizing the first surface in ramp mode, galvano-static mode, and galvano-pulsed mode, p.9, line 30; p.11, lines 14-15) said first surface for a time sufficient to cover it with the copper-dopant metal alloy (for a period of time sufficient to carry out conformal and complete filling with the alloy of Cu-Mn or Cu-Zn, p.9, lines 30-33), and
c) annealing the alloy to cause it to separate (annealing the alloy deposit of Cu-Mn or Cu-Zn forming two layers, p.12, lines 20-23) and form a first layer of copper and a second layer comprising the dopant metal and/or an oxide thereof (form the first layer comprising essentially Cu, and the second layer comprising essentially Mn or Zn),
wherein the dopant metal is selected from the group consisting of manganese and zinc (the second metal is selected from Mn or Zn, p.5, lines 5-6);
wherein the metal layer comprises a second surface which is in contact with a mixed surface comprising both an insulating area (the first conductive surface of the metallic seed layer having a second surface in contact with a dielectric material comprising silicon oxide, p.10, lines 5-7) and a conducting area (the metallic seed layer covering an insulating material and forming conductive metal interconnects and vias connecting different levels of integration, p.7, lines 2-4, p.13, lines 30-32),
said insulating area being made of a dielectric material (the dielectric material comprising silicon dioxide, p.10, lines 5-7) and
said conducting area being made of a contact metal selected from the group consisting of tungsten, molybdenum, cobalt and ruthenium (the metal comprising tungsten, cobalt, and ruthenium, p.10 lines 10-13),
said contact metal being intended to connect a copper bit line and the semiconductor device (conductive metal interconnects and vias connecting different levels of integration in semiconductor devices, p.13, lines 30-32).
Mevellec does not teach that the semiconductor device is a 3D-NAND flash memory.
Liu teaches a process (FIG. 3E, [0012]) for fabricating a 3D-NAND flash memory (3D memory device is a NAND flash memory device, [0031]), including formation of conductive interconnect structures and bit lines using electroplating/electrodeposition techniques [0059-0060].
As taught by Liu, one of ordinary skill in the art would utilize and modify the above teaching into Mevellec to obtain and achieve the process for fabricating the 3D-NAND flash memory as claimed, because electroplating facilitates conductive filling of openings in the vertically stacked interconnect structures of a 3D NAND memory device [0031, 0060].
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ the teaching as taught by Liu in combination with Mevellec due to the above reason.
Mevellec in view of Liu does not teach that the electrolyte comprises a tetra-alkylammonium salt and an aliphatic polyamine having from 2 to 4 amino groups to electrodeposit a copper-dopant metal alloy, wherein the electrolyte has a pH between 6.0 and 10.0.
RELIGIEUX teaches a process for electrodeposition (electrodeposition using copper (II), [0115])
wherein the electrolyte comprises a tetra-alkylammonium salt and an aliphatic polyamine having from 2 to 4 amino groups (an electrodeposition solution corresponding to the claimed electrolyte comprises a tetra-ethyl-ammonium hydroxide and ethylenediamine having two amino groups, [0121, 0125]),
wherein the electrolyte has a pH between 6.0 and 10.0 (the electrolyte has a pH of 9.2, [0125]).
As taught by RELIGIEUX, one of ordinary skill in the art would utilize and modify the above teaching into Mevellec in view of Liu to obtain and achieve the process comprising the electrolyte comprising a tetra-alkylammonium salt and an aliphatic polyamine having from 2 to 4 amino groups to electrodeposit a copper-dopant metal alloy, wherein the electrolyte has a pH between 6.0 and 10.0 as claimed, because ethylenediamine improves copper filling performance [0135, 0138] and tetraethylammonium hydroxide adjusts the electrolyte pH [0158-0159], thereby providing efficient copper electrodeposition and filling [0017].
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ the teaching as taught by RELIGIEUX in combination with Mevellec in view of Liu due to the above reason.
Mevellec in view of Liu and RELIGIEUX does not teach the process wherein the contact metal is intended to connect a polysilicon channel.
Kim874 teaches a process for fabricating a 3D-NAND flash memory (100, FIGS. 1 and 5, [0032]), wherein a contact metal is intended to connect a polysilicon channel (a bit line 116 electrically coupled to the conductive channel 110 comprising polysilicon, [0032, 0038]).
As taught by Kim874, one of ordinary skill in the art would utilize and modify the above teaching into Mevellec in view of Liu and RELIGIEUX to obtain and achieve the process for fabricating the 3D-NAND flash memory wherein the contact metal is intended to connect the polysilicon channel as claimed, because 3D-NAND flash memory architectures conventionally utilize conductive interconnect and contact structures electrically connecting bit lines and polysilicon channel structures to facilitate electrical signal transmission and operation of vertically stacked memory strings [0003-0004].
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to employ the teaching as taught by Kim874 in combination with Mevellec in view of Liu and RELIGIEUX due to the above reason.
Response to Arguments
Applicant's arguments with respect to claims have been considered but are moot in view of the new ground of rejection. Arguments regarding the newly added limitations are addressed in the rejection above.
Applicant submits, on page 6 of the Remarks, that:
“Applicant respectfully submits that the Examiner fails to recognize the importance and necessity of maintaining the pH within the range of 1.8 to 4 in Mevellec as well as the disadvantages arising when the pH falls outside this range. Mevellec clearly sets forth the importance and necessity of maintaining the pH within this range as well as the disadvantages that arise when the pH falls outside this range. Therefore, this is an important technical feature of Mevellec that cannot be arbitrarily adjusted”.
The Examiner respectfully disagrees.
Mevellec identifies the pH range of 1.8 to 4.0 and describes particular advantages associated with operation within that range. In particular, Mevellec explains that “it is not necessary to operate at a pH of more than 4 in order to limit corrosion of the cobalt or copper in the deposit” (p.5, lines 35-36). The claimed electrolyte composition and pH are addressed by RELIGIEUX for the reasons set forth in the rejection above. Accordingly, Applicant’s argument is not persuasive.
Applicant’s substantially similar arguments with respect to claims 18 and 19 are not persuasive for the same reasons discussed above.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant’s disclosure in that ZAHRAOUI et al. (US 2009/0294293) and Gonzalez et al. (US 2007/0272560) as processes for electrodeposition of copper using electrolytes comprising additives.
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/JIYOUNG OH/Examiner, Art Unit 2818
/DUY T NGUYEN/Primary Examiner, Art Unit 2818 10/7/26
