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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 9/26/2025 has been entered.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claim(s) 1-3, 6-11, 14, 15, and 17-20 is/are rejected under 35 U.S.C. 103 as being unpatentable over Hung et al. (US 2018/0174970 A1; hereinafter Hung).
Regarding claim 1, Hung discloses a semiconductor structure (Fig. 1 of Hung; “FIG. 1 illustrates a top view of a semiconductor device” (¶ 0008 of Hung, emphasis added)), comprising:
a metal gate structure1 (a combination of (1) “work function metal layer 40” within “gate structure[s] 22 24”2 (¶ 0018) shown in Fig. 7 which is a “cross-section [of the] semiconductor device . . . in FIG. 1” (¶ 0009) and (2) “a high-k dielectric layer 38” within “gate structure[s] 22, 24” (¶ 0018) also shown in Fig. 7) including a gate dielectric layer (“high-k dielectric layer 38”3 (¶ 0018)) and a gate electrode (“metal layer 40”4 (¶ 0018)), the metal gate structure including a first sidewall (left sidewall of central 38 in Fig. 7) and a second sidewall (right sidewall of rightmost 38 in Fig. 7) opposing the first sidewall in a cross-sectional view perpendicular to a lengthwise direction of the metal gate structure, the gate electrode including at least a first metal (the first metal being aluminum (“work function metal layer 40 . . . may include titanium aluminide (TiAl)”; ¶ 0020 of Hung));
a conductive layer5 (a combination of (1) “the low-resistance metal layer 42” within “gate structure[s] 22, 24” (¶ 0018) shown in Fig. 7 and (2) “barrier layer 58” which is formed of conductive metal (¶ 0024) over Hung’s gate structures 22, 24 shown in Fig. 7) formed above the gate electrode (as seen in Fig. 7, both components 42 and 58 of the conductive layer of Hung are formed over gate electrode 40 of Hung; as such, the conductive layer of Hung is considered to be ‘above’ the gate electrode), the conductive layer including an alloy layer (component 42; “low-resistance metal layer 42 may include . . . titanium aluminum (TiAl)”; ¶ 0020), the alloy layer including at least the first metal (aluminum, as discussed above) and a second metal (titanium) different from the first metal, the alloy layer extending from a position below a top surface of the metal gate structure (“a top surface” being the upper surface of 406 within Hung’s components 22, 24 which directly contacts component 58; see annotated copy of Fig. 7, below. Further, as seen in Fig. 7, the bottommost portion of component 42 is below the cited top surface of the metal gate structure) to a position above the top surface of the metal gate structure (as seen in Fig. 7, the topmost portion of component 42 is above the cited top surface of the metal gate structure); and
a contact feature (“metal layer 60” (¶ 0024) above Hung’s components 22, 24 shown in Fig. 7) disposed above the metal gate structure (see Fig. 7), wherein the contact feature is in direct contact with a top surface of the conductive layer (“a top surface” being the upper surface of 587 above Hung’s components 22, 42 which directly contacts the bottom of component 60; see annotated copy of Fig. 7, below. Further, as seen in Fig. 7, contact feature 60 of Hung is in direct contact with the top surface of the conductive layer),
wherein a topmost portion of the conductive layer (component 58 of Hung is considered to be the “topmost portion of the conductive layer”) is directly under the contact feature (as seen in Fig. 7 of Hung, component 58 is directly under contact feature 60), and wherein laterally the conductive layer is fully between the first and second sidewalls of the metal gate structure in the cross-sectional view (see Fig. 7).
With regards to the contact feature being in direct contact with a topmost surface of the conductive layer, Fig. 7 of Hung does not show this feature as the semiconductor structure has been planarized (¶ 0024 of Hung). However, Hung discloses that the device may not be planarized (¶ 0011) and without such a planarization process it would have been obvious to one having ordinary skill in the art before the Application's effective filing date to deposit enough material for the gate contact such that the topmost surface of the metal film 58 will be under a bottom surface of the gate contact 60 for the benefit of ensuring the entirety of the cavity is filled (as Hung discloses that metal film 58 and gate contact 60 are sequentially deposited with gate contact 60 over metal film 58 (¶ 0024); see mocked up rendering of the relevant portion of the semiconductor structure immediately prior to the planarization step which is presented purely as a visual aid and is not a perfectly accurate visual description of the structure).
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Regarding claim 2, Hung discloses the semiconductor structure of claim 1, as discussed above. Hung further discloses that the conductive layer further includes a metallic film (“barrier layer 58” (¶ 0024 of Hung) which, as discussed in the rejection of claim 1, is part of the conductive layer) of the second metal (as discussed in the rejection of claim 1, the second metal is titanium. Hung discloses that the metallic film may be titanium (“the barrier layer 58 is selected from the group consisting of Ti . . .”; ¶ 0024) disposed above the alloy layer (as seen in Fig. 7 of Hung, metallic film 58 is disposed above alloy layer 42).
Regarding claim 8, Hung discloses the semiconductor structure of claim 1, as discussed above. Hung further discloses that the conductive layer is self-aligned with the gate electrode (Hung discloses that portion 42 of the conductive layer is designed to align itself automatically with gate electrode 40 (“work function metal layer 40, and a low resistance metal layer 42 are sequentially formed in the recesses”; ¶ 0018 of Hung). As such, the conductive layer is self-aligned with the gate electrode).
Regarding claim 9, Hung discloses the semiconductor structure of claim 1, as discussed above. Hung further discloses that the conductive layer includes a top portion (portion of 58 above the metal gate structure as shown in Fig. 7 of Hung) above the top surface of the metal gate structure (as discussed in the rejection of claim 1, above, the top surface of the metal gate structure is the upper surface of 40 within Hung’s components 22, 24 which directly contacts component 58 in Fig. 7, which is entirely beneath the cited top portion of the conductive layer) and a bottom portion (portion of 58 below the aforementioned top surface of the metal gate structure in Fig. 7) below the top surface of the metal gate structure (per definition).
Hung does not explicitly disclose the thicknesses of these portions to determine if the fall within the claimed range.
However, there was a benefit to forming the entirety of component 58 of Hung to have a substantially uniform thickness in that component 58 (which, as discussed above, functions as a barrier) would be of sufficient thickness to effectively act as a barrier to all of the components to which it is adjacent while minimizing the amount of material used (i.e., no thin spots which would result in degraded protection and no overly thick spots which would waste material).
It would have been obvious to one having ordinary skill in the art before the Application's effective filing date would have formed component 58 of Hung to have a uniform thickness for this benefit. As such, and as demonstrated in the annotated copy of Fig. 7, below, the ratio of a thickness of the top portion to a thickness of the bottom portion would be substantially 1:1; since 1:1 falls within the claimed range of about 1:8 to about 1.5:1, the range is anticipated (MPEP § 2131.03)).
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Alternatively regarding claim 18, Hung discloses a semiconductor structure (Fig. 1 of Hung; “FIG. 1 illustrates a top view of a semiconductor device” (¶ 0008 of Hung, emphasis added)), comprising:
a metal gate structure9 (a combination of (1) “work function metal layer 40” within “gate structure[s] 22, 24”10 (¶ 0018) shown in Fig. 7 which is a “cross-section [of the] semiconductor device . . . in FIG. 1” (¶ 0009) and (2) “a high-k dielectric layer 38” within “gate structure[s] 22, 24” (¶ 0018) also shown in Fig. 7) including a gate dielectric layer (“high-k dielectric layer 38”11 (¶ 0018)) and a gate electrode (“metal layer 40”12 (¶ 0018)), the metal gate structure including a first sidewall (left sidewall of central 38 in Fig. 7) and a second sidewall (right sidewall of rightmost 38 in Fig. 7) opposing the first sidewall in a cross-sectional view perpendicular to a lengthwise direction of the metal gate structure, the gate electrode including at least a first metal (the first metal being aluminum (“work function metal layer 40 . . . may include titanium aluminide (TiAl)”; ¶ 0020 of Hung));
a conductive layer (“the low-resistance metal layer 42” within “gate structure[s] 22, 24” (¶ 0018) shown in Fig. 7) formed above the gate electrode (as seen in Fig. 7, conductive layer 42 of Hung is formed over gate electrode 40 of Hung; as such, the conductive layer of Hung is considered to be ‘above’ the gate electrode), the conductive layer including an alloy layer (a combination of copper and aluminum; “low-resistance metal layer 42 may include copper (Cu), aluminum (Al) . . . or any combination thereof”13; ¶ 0020), the alloy layer including at least the first metal (aluminum, as discussed above) and a second metal (copper, as discussed above) different from the first metal, the alloy layer extending from a position below a top surface of the metal gate structure (“a top surface” being the upper surface of 4014 within Hung’s components 22, 24 which directly contacts component 58; see annotated copy of Fig. 7, below. Further, as seen in Fig. 7, the bottommost portion of component 42 is below the cited top surface of the metal gate structure) to a position above the top surface of the metal gate structure (as seen in Fig. 7, the topmost portion of component 42 is above the cited top surface of the metal gate structure); and
a contact feature (component 52 in Fig. 7 of Hung which comprises “metal layer 60” and “barrier layer 58” (¶ 0024) above Hung’s components 22, 24 shown in Fig. 7) disposed above the metal gate structure (see Fig. 7), wherein the contact feature is in direct contact with a top surface of the conductive layer (“a top surface” being the upper surface of 4215 which directly contacts the bottom of component 58; see annotated copy of Fig. 7, below. As just noted and as seen in Fig. 7, contact feature 52 of Hung is in direct contact with the top surface of the conductive layer),
wherein a topmost portion of the conductive layer (the upper half of the conductive layer 42 in Fig. 7 of Hung, see annotated copy below) is directly under the contact feature (as seen in Fig. 7 of Hung, the topmost portion is directly under contact feature 52), and wherein laterally the conductive layer is fully between the first and second sidewalls of the metal gate structure in the cross-sectional view (see Fig. 7).
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With regards to the contact feature being in direct contact with a topmost surface of the conductive layer, Fig. 7 of Hung does not show this feature as the semiconductor structure has been planarized (¶ 0024 of Hung). However, Hung discloses that the device may not be planarized (¶ 0011) and without such a planarization process it would have been obvious to one having ordinary skill in the art before the Application's effective filing date to deposit enough material for the gate contact such that the topmost surface of the metal film 58 will be under a bottom surface of the gate contact 60 for the benefit of ensuring the entirety of the cavity is filled (as Hung discloses that metal film 58 and gate contact 60 are sequentially deposited with gate contact 60 over metal film 58 (¶ 0024); see mocked up rendering of the relevant portion of the semiconductor structure immediately prior to the planarization step which is presented purely as a visual aid and is not a perfectly accurate visual description of the structure).
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Regarding claim 3, Hung discloses the semiconductor structure of claim 1, as discussed in the first alternative rejection of claim 1 above. Hung further discloses that the first metal is aluminum (see discussion of the first metal in the first alternative rejection of claim 1, above) and that the second metal is copper (see discussion of the second metal in the first alternative rejection of claim 1, above).
Regarding claim 6, Hung discloses the semiconductor structure of claim 1, as discussed in the first alternative rejection of claim 1 above. Further, in the semiconductor structure of Hung, a contact resistance at an interface between the contact feature and the conductive layer (interface between contact feature 52 and conductive layer 42 of Hung, as seen in Fig. 7) will be lower than a contact resistance an interface between the contact feature and the metal gate structure (interface between the contact feature 52 and gate electrode 40 of Hung) as the materials16 of the contact feature, the conductive layer, and the metal gate structure are disclosed as suitable materials for achieving the relative contact resistances (Hung discloses that the composition of component 58 (i.e., the part of the conductive feature at the interface) may be titanium or tantalum (¶ 0024 of Hung) which Applicant states are suitable materials for the conductive feature (¶ 0039 of the Application as originally filed); Hung discloses that the composition of the conductive layer is a combination of aluminum and copper (see discussion in the first alternative rejection of claim 1, above) which Applicant states is a suitable material for the conductive layer (¶ 0046 of the Application as originally filed); and Hung discloses that the composition of component 40 (i.e., the part of the metal gate structure at the interface) may be a work function metal layer of titanium nitride or tantalum nitride (¶ 0020 of Hung) which Applicant states are suitable materials for the metal gate structure (¶ 0024 of the Application as originally filed). As the materials disclosed by Hung are the same composition as those disclosed by Applicant, they will inherently have the same properties. “Where the claimed and prior art products are identical or substantially identical in . . . composition . . . a prima facie case of either anticipation or obviousness has been established. In re Best, 562 F.2d 1252, 1255, 195 USPQ 430, 433 (CCPA 1977). ‘When the PTO shows a sound basis for believing that the products of the applicant and the prior art are the same, the applicant has the burden of showing that they are not.’ In re Spada, 911 F.2d 705, 709, 15 USPQ2d 1655, 1658 (Fed. Cir. 1990).” (MPEP 2112.01(I)).
Further alternatively regarding claim 117, Hung discloses a semiconductor structure (Fig. 1 of Hung; “FIG. 1 illustrates a top view of a semiconductor device” (¶ 0008 of Hung, emphasis added)), comprising:
a metal gate structure18 (a combination of (1) “work function metal layer 40” within “gate structure[s] 22, 24”19 (¶ 0018) shown in Fig. 7 which is a “cross-section [of the] semiconductor device . . . in FIG. 1” (¶ 0009) and (2) “a high-k dielectric layer 38” within “gate structure[s] 22, 24” (¶ 0018) also shown in Fig. 7) including a gate dielectric layer (“high-k dielectric layer 38”20 (¶ 0018)) and a gate electrode (“metal layer 40”21 (¶ 0018)), the metal gate structure including a first sidewall (left sidewall of central 38 in Fig. 7) and a second sidewall (right sidewall of rightmost 38 in Fig. 7) opposing the first sidewall in a cross-sectional view perpendicular to a lengthwise direction of the metal gate structure, the gate electrode including at least a first metal (the first metal being aluminum (“work function metal layer 40 . . . may include . . . tantalum aluminide (TaAl)”; ¶ 0020 of Hung));
a conductive layer22 (a combination of (1) “the low-resistance metal layer 42” within “gate structure[s] 22, 24” (¶ 0018) shown in Fig. 7; (2) “barrier layer 58” (¶ 0024) over Hung’s gate structures 22, 24 shown in Fig. 7; and (3) the “optional barrier layer (not shown)” (¶ 0020)) formed above the gate electrode (as seen in Fig. 7, both components 42 and 58 of the conductive layer of Hung are formed over gate electrode 40 of Hung, further ¶ 0020 of Hung discloses that the barrier layer is between component 42 and gate electrode 40 and, therefore, would also be above the gate electrode 40; as such, the conductive layer of Hung is considered to be ‘above’ the gate electrode), the conductive layer including an alloy layer (combination of (1) component 42; “low-resistance metal layer 42 may include . . . titanium aluminum (TiAl)”; ¶ 0020 and (2) the barrier layer, using tantalum for the material of the barrier layer (¶ 0020 of Hung))23, the alloy layer including at least the first metal (aluminum, as discussed above) and a second metal (titanium, as discussed above) different from the first metal, the alloy layer extending from a position below a top surface of the metal gate structure (“a top surface” being the upper surface of 4024 within Hung’s components 22, 24 which is directly beneath component 58; see annotated copy of Fig. 7, below. Further, as seen in Fig. 7, the bottommost portion of component 42 is below the cited top surface of the metal gate structure) to a position above the top surface of the metal gate structure (as seen in Fig. 7, the topmost portion of component 42 is above the cited top surface of the metal gate structure); and
a contact feature (“metal layer 60” (¶ 0024) above Hung’s components 22, 24 shown in Fig. 7) disposed above the metal gate structure (see Fig. 7), wherein the contact feature is in direct contact with a top surface of the conductive layer (“a top surface” being the upper surface of 5825 above Hung’s components 22, 24 which directly contacts the bottom of component 60; see annotated copy of Fig. 7, below. Further, as seen in Fig. 7, contact feature 60 of Hung is in direct contact with the top surface of the conductive layer),
wherein a topmost portion of the conductive layer (component 58 of Hung is considered to be the “topmost portion of the conductive layer”) is directly under the contact feature (as seen in Fig. 7 of Hung, component 58 is directly under contact feature 60), and wherein laterally the conductive layer is fully between the first and second sidewalls of the metal gate structure in the cross-sectional view (see Fig. 7).
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With regards to the contact feature being in direct contact with a topmost surface of the conductive layer, Fig. 7 of Hung does not show this feature as the semiconductor structure has been planarized (¶ 0024 of Hung). However, Hung discloses that the device may not be planarized (¶ 0011) and without such a planarization process it would have been obvious to one having ordinary skill in the art before the Application's effective filing date to deposit enough material for the gate contact such that the topmost surface of the metal film 58 will be under a bottom surface of the gate contact 60 for the benefit of ensuring the entirety of the cavity is filled (as Hung discloses that metal film 58 and gate contact 60 are sequentially deposited with gate contact 60 over metal film 58 (¶ 0024); see mocked up rendering of the relevant portion of the semiconductor structure immediately prior to the planarization step which is presented purely as a visual aid and is not a perfectly accurate visual description of the structure).
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Regarding claim 7, Hung discloses the semiconductor structure of claim 1, as discussed in the second alternative rejection of claim 1 above. Hung further discloses that the gate electrode includes a third metal (tantalum; as discussed in the second alternative rejection of claim 1, above, the gate electrode 40 of Hung comprises TaAl (¶ 0020 of Hung)) different from either the first metal or the second metal, and the alloy layer includes a center portion (42, which is the center of the alloy layer) rich of the first metal (as discussed in the second alternative rejection of claim 1, above, component 42 comprises TiAl, which is 50% aluminum which is interpreted as being ‘rich’ of aluminum) and a side portion (the barrier layer, which, as discussed above, is formed between components 40 and 42 in Fig. 7 and, therefore, forms the side of the alloy layer) rich of the third metal (as discussed in the second alternative rejection of claim 1, above, the barrier layer of Hung consists of tantalum which is interpreted as being ‘rich’ of tantalum).
Regarding claim 10, Hung discloses a semiconductor structure (Fig. 1 of Hung; “FIG. 1 illustrates a top view of a semiconductor device” (¶ 0008 of Hung, emphasis added)), comprising:
a metal gate structure26 (a combination of (1) “work function metal layer 40” within “gate structure[s] 22, 24”27 (¶ 0018) shown in Fig. 7 which is a “cross-section [of the] semiconductor device . . . in FIG. 1” (¶ 0009); and (2) “a high-k dielectric layer 38” within “gate structure[s] 22, 24” (¶ 0018) also shown in Fig. 7) having a first (left sidewall of central 38 in Fig. 7) and a second sidewall (right sidewall of rightmost 38 in Fig. 7) opposing the first sidewall in a cross-sectional view perpendicular to a lengthwise direction of the metal gate structure;
an alloy layer (combination of (1) “the low-resistance metal layer 42” within “gate structure[s] 22, 24” (¶ 0018) shown in Fig. 7, using a combination of CoWP and TiAl for the composition28; “low-resistance metal layer 42 may include . . . titanium aluminum (TiAl), cobalt tungsten phosphide (CoWP) or any combination thereof”29; ¶ 0020 and (2) hardmask 44) deposited on the metal gate structure (as seen in Fig. 7, alloy layer 42 of Hung is formed over the metal gate structure of Hung), the alloy layer extending from a position below a topmost surface of the metal gate structure to a position above the topmost surface of the metal gate structure, the alloy layer including at least the first metallic element (titanium, as discussed above) and a second metallic element (tungsten, as discussed above);
a metal film of the second metallic element30 (“barrier layer 58” which may comprise tungsten nitride (¶ 0024) over Hung’s gate structure 22, 24 shown in Fig. 7, tungsten being the second metallic element) deposited on the alloy layer (as seen in Fig. 7 of Hung, metal film 58 is on alloy layer 42); and
a gate contact landing (“metal layer 60” (¶ 0024) above Hung’s components 22, 24 shown in Fig. 7) on the metal film (as seen in Fig. 7 of Hung, the gate contact landing 60 of Hung is on the metal film 58) wherein laterally the alloy layer is fully between the first and second sidewalls of the metal gate structure in the cross-sectional view (see Fig. 7).
With regards to a topmost surface of the metal film being under a bottom surface of the gate congtact, Fig. 7 of Hung does not show this feature as the semiconductor structure has been planarized (¶ 0024 of Hung). However, immediately prior to the planarization step, it would have been obvious to one having ordinary skill in the art before the Application's effective filing date to deposit enough material for the gate contact such that the topmost surface of the metal film 58 will be under a bottom surface of the gate contact 60 for the benefit of ensuring the entirety of the cavity is filled (as Hung discloses that metal film 58 and gate contact 60 are sequentially deposited with gate contact 60 over metal film 58 (¶ 0024); see mocked up rendering of the relevant portion of the semiconductor structure immediately prior to the planarization step which is presented purely as a visual aid and is not a perfectly accurate visual description of the structure). As this intermediate product of Hung is still a “semiconductor structure”, this obvious intermediate product of Hung satisfies all the limitations of claim 10.
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Regarding claim 11, Hung discloses the semiconductor structure of claim 10, as discussed above. Hung further discloses using compositions for the metal gate structure which include the first metallic element (titanium, as discussed in the rejection of claim 10, above) but are substantially free of the second metallic element (tungsten, as discussed in the rejection of claim 10, above) (as discussed in the rejection of claim 10, above, the components of the metal gate structure of Hung are 38 and 40; Hung discloses using lead zirconate titanate for component 38 (¶ 0019) and using titanium nitride for component 40 (¶ 0020), which both include the first metallic element while being substantially free of the second metallic element).
Regarding claim 14, Hung discloses the semiconductor structure of claim 10, as discussed above. Hung further discloses wherein the first metallic element is titanium (see discussion in the rejection of claim 10, above) and the second metallic element is tungsten (see discussion in the rejection of claim 10, above).
Alternatively regarding claim 1031, Hung discloses a semiconductor structure (Fig. 1 of Hung; “FIG. 1 illustrates a top view of a semiconductor device” (¶ 0008 of Hung, emphasis added)), comprising:
a metal gate structure32 (a combination of (1) “work function metal layer 40” within “gate structure[s] 22, 24”33 (¶ 0018) shown in Fig. 7 which is a “cross-section [of the] semiconductor device . . . in FIG. 1” (¶ 0009); (2) “a high-k dielectric layer 38” within “gate structure[s] 22, 24” (¶ 0018) also shown in Fig. 7; and (3) “gate dielectric layer 26” within “gate structure[s] 22, 24” (¶ 0018) also shown in Fig. 7) having a first sidewall (left sidewall of central 38 in Fig. 7) and a second sidewall (right sidewall of rightmost 38 in Fig. 7) opposing the first sidewall in a cross-sectional view perpendicular to a lengthwise direction of the metal gate structure;
an alloy layer (combination of (1) “the low-resistance metal layer 42” within “gate structure[s] 22, 24” (¶ 0018) shown in Fig. 7, using a combination of CoWP and TiAl for the composition34; “low-resistance metal layer 42 may include . . . titanium aluminum (TiAl), cobalt tungsten phosphide (CoWP) or any combination thereof”35; ¶ 0020 and (2) hardmask 44) deposited on the metal gate structure (as seen in Fig. 7, alloy layer 42 of Hung is formed over the metal gate structure of Hung), the alloy layer extending from a position below a topmost surface of the metal gate structure to a position above the topmost surface of the metal gate structure, the alloy layer including at least the first metallic element (titanium, as discussed above) and a second metallic element (tungsten, as discussed above);
a metal film of the second metallic element36 (“barrier layer 58” which may comprise tungsten nitride (¶ 0024) over Hung’s gate structure 22, 24 shown in Fig. 7, tungsten being the second metallic element) deposited on the alloy layer (as seen in Fig. 7 of Hung, metal film 58 is on alloy layer 42); and
a gate contact landing (“metal layer 60” (¶ 0024) above Hung’s components 22, 24 shown in Fig. 7) on the metal film (as seen in Fig. 7 of Hung, the gate contact landing 60 of Hung is on the metal film 58) wherein laterally the alloy layer is fully between the first and second sidewalls of the metal gate structure in the cross-sectional view (Component 42 is formed completely within component 40, which is part of the metal gate structure (see Fig. 7).
With regards to a topmost surface of the metal film being under a bottom surface of the gate congtact, Fig. 7 of Hung does not show this feature as the semiconductor structure has been planarized (¶ 0024 of Hung). However, immediately prior to the planarization step, it would have been obvious to one having ordinary skill in the art before the Application's effective filing date to deposit enough material for the gate contact such that the topmost surface of the metal film 58 will be under a bottom surface of the gate contact 60 for the benefit of ensuring the entirety of the cavity is filled (as Hung discloses that metal film 58 and gate contact 60 are sequentially deposited with gate contact 60 over metal film 58 (¶ 0024); see mocked up rendering of the relevant portion of the semiconductor structure immediately prior to the planarization step which is presented purely as a visual aid and is not a perfectly accurate visual description of the structure). As this intermediate product of Hung is still a “semiconductor structure”, this obvious intermediate product of Hung satisfies all the limitations of claim 10.
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Regarding claim 15, Hung discloses the semiconductor structure of claim 10, as discussed in the alternative rejection of claim 10, above. Hung further discloses wherein the metal gate structure includes a gate dielectric layer (“gate dielectric layer 26”; ¶ 0018), a capping layer (“high-k dielectric layer 38”37 (¶ 0018)) over the gate dielectric layer (as seen in Fig. 7 of Hung, capping layer 38 is over the gate dielectric layer 26); and a gate electrode (“metal layer 40”38 (¶ 0018)) over the capping layer,39 and wherein a boundary of the alloy layer is aligned with a boundary of the gate electrode (as seen in Fig. 7 of Hung, the side and bottom surfaces of the alloy layer 42 are directly contacting, and therefore aligned with, gate electrode 40).
Regarding claim 17, Hung discloses a semiconductor structure (Fig. 1 of Hung; “FIG. 1 illustrates a top view of a semiconductor device” (¶ 0008 of Hung, emphasis added)), comprising:
a metal gate structure40 (a combination of (1) “work function metal layer 40” within “gate structure[s] 22, 24”41 (¶ 0018) shown in Fig. 7 which is a “cross-section [of the] semiconductor device . . . in FIG. 1” (¶ 0009) and (2) the combination of “a high-k dielectric layer 38” within “gate structure[s] 22, 24” (¶ 0018) also shown in Fig. 7 and dielectric layers 30, 62, and 36) including a gate dielectric layer (“high-k dielectric layer 38” combined with dielectric layers 30, 62, and 3642 (¶ 0018)) and a gate electrode (“metal layer 40”43 (¶ 0018)), wherein in a cross-sectional view perpendicular to a lengthwise direction of the metal gate structure (Fig. 7 view), the gate dielectric layer includes a first inner sidewall (leftmost inner sidewall of central 38 in Fig. 7) facing the gate electrode layer and a second inner sidewall (rightmost inner sidewall of rightmost 38 in Fig. 7) facing the gate electrode, and wherein the gate electrode layer is laterally disposed between the first and second inner sidewalls of the gate dielectric layer (see Fig. 7);
a conductive layer44 (a combination of (1) “the low-resistance metal layer 42” within “gate structure[s] 22, 24” (¶ 0018) shown in Fig. 7 and (2) “barrier layer 58” (¶ 0024) over Hung’s gate structure 22, 24 shown in Fig. 7) formed on and in contact with the gate electrode (as seen in Fig. 7, both components 42 and 58 of the conductive layer of Hung are formed on and in contact with gate electrode 40 of Hung), wherein in the cross-sectional view the conductive layer as a whole is laterally fully between the first and second inner sidewalls of the gate dielectric layer (see Fig. 7); and
a gate contact (“metal layer 60” (¶ 0024) above Hung’s components 22, 24 shown in Fig. 7) disposed on the conductive layer, wherein a topmost surface of the conductive layer (see annotated copy of Fig. 7, below) is below a bottom surface of the gate contact (see Fig. 7) and above a topmost surface of the gate dielectric layer (see Fig. 7).
Regarding claim 18, Hung discloses the semiconductor structure of claim 17, as discussed above. Hung further discloses that the gate electrode layer 40 comprises titanium aluminide (“40 . . . may include titanium aluminide (TiAl)”; ¶ 0020) which includes a first metal (titanium) and a second metal (aluminum) different from the first metal, and the conductive layer comprises a combination of copper and TiAl (“low-resistance metal layer 42 may include copper (Cu) . . . titanium aluminum (TiAl) . . . or any combination thereof”45; ¶ 0020) which includes the first metal (titanium), the second metal (aluminum), and a third metal (copper) different from either the first metal or the second metal.
Regarding claim 19, Hung discloses the semiconductor structure of claim 17, as discussed above. Hung further discloses the conductive extending vertically from a position below a top surface of the metal gate structure (“a top surface” being the upper surface of 4046 within Hung’s components 22, 24 which directly contacts component 58; see annotated copy of Fig. 7, below. Further, as seen in Fig. 7, the bottommost portion of component 42 is below the cited top surface of the metal gate structure) to a position above the top surface of the metal gate structure (as seen in Fig. 7, the topmost portion of component 42 is above the cited top surface of the metal gate structure).
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Regarding claim 20, Hung discloses the semiconductor structure of claim 19, as discussed above. Further, in the semiconductor structure of Hung, there will exist a portion of the conductive layer below the top surface of the metal gate structure which has a thickness less than 8nm (the Examiner notes claim 20 is written broadly in the sense that “a portion” does not require any specific boundaries or minimum quantities and, further, “a portion of the conductive layer below the top surface of the metal gate structure” does not automatically include all portions of the conductive layer which are below the top surface of the metal gate structure. Rather, the part of the conductive layer which is below the top surface of the metal gate structure may comprise a multitude of “portions” which, as discussed, do not require any specific boundaries or minimum quantities. As such, a single atom within the conductive layer may be considered “a portion of the conductive layer” under its broadest reasonable interpretation. Therefore, as some of the conductive layer of Hung exists below the top surface of the gate structure (as discussed in the rejection of claim 19, above) there will be an atom within the conductive layer below the top surface of the gate structure (there will, of course, be several atoms but “a portion” only needs to include one) and as atoms have thicknesses in the sub-nanometer scale, there will be a portion (that atom) of the conductive layer below the top surface of the metal gate structure that has a thickness of less than 8nm. If Applicant were to amend claim 20 to instead recite that “the total amount of the conductive layer below the top surface of the metal gate structure has a thickness less than 8nm” then this line of reasoning would no longer be applicable.).
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Allowable Subject Matter
Claim 4 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter: the prior art of record does not disclose a semiconductor structure which satisfies all of the limitations of Applicant’s claim 1 and further includes a metal oxide within the conductive layer wherein a concentration of the metal oxide in the conductive layer increases in a direction towards the gate electrode. Hung, the closest prior art of record, discloses a semiconductor structure which satisfies claim 1 (see any of the rejections of claim 1, above) but the conductive layer does not include a metal oxide, let alone a metal oxide in such a way that the concentration of the metal oxide increases in a direction toward the gate electrode. Further, it would not have been obvious to one having ordinary skill in the art before the Application's effective filing date to include such a metal oxide in the conductive layer of Hung as it would increase the complexity of the fabrication process and require the inclusion of additional materials.
Response to Arguments
Applicant’s arguments with respect to the prior mapping of Hung have been fully considered and are persuasive. Therefore, the rejections have been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of new mappings of Hung, shown in the rejections above.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to CHRISTOPHER A CULBERT whose telephone number is (571)272-4893. The examiner can normally be reached M-F 9-5.
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/CHRISTOPHER A CULBERT/Examiner, Art Unit 2815
1 The Examiner notes that ‘structure’, as the term is used by Applicant, does not require that it consists of only a single component but, instead, may consist of multiple distinct components. Further, the Examiner notes that “metal gate structure” does not require the structure to consist only of metals, as claim 1 requires the “metal gate structure” to also comprise a dielectric layer.
2 Figs. 1 and 7 of Hung show gate structures 20, 22, and 24 which have distinct configurations. This Office action will use gate structure 20 for reference.
3 Dielectric layer 38 of Hung is considered a “gate dielectric layer” as it is a dielectric layer in the gate structure between the gate electrode and underlying substrate 12 of Hung.
4 Although the text of Hung does not use the term ‘electrode’, metal layer 40 of Hung is a conductor within the gate structure used to establish electrical contact with the underlying substrate 12 of Hung and is, therefore, considered a “gate electrode”.
5 The Examiner notes that a “layer” is interpreted as allowing for the inclusion of a plurality of sub-layers.
6 The Examiner notes that this surface is a surface of an object that faces upwards and would be seen if looking down from directly above and, therefore, may be considered a “top surface”, even though it is not a “topmost surface”. Were Applicant to amend the claim to require this surface to be a “topmost surface”, this rejection would be overcome.
7 The Examiner notes that this surface is a surface of an object that faces upwards and would be seen if looking down from directly above and, therefore, may be considered a “top surface”, even though it is not a “topmost surface”. Were Applicant to amend the claim to require this surface to be a “topmost surface”, this rejection would be overcome.
8 This specific rejection of claim 1 will hereinafter be referenced as the “first alternative rejection of claim 1”.
9 The Examiner notes that ‘structure’, as the term is used by Applicant, does not require that it consists of only a single component but, instead, may consist of multiple distinct components. Further, the Examiner notes that “metal gate structure” does not require the structure to consist only of metals, as claim 1 requires the “metal gate structure” to also comprise a dielectric layer.
10 Figs. 1 and 7 of Hung show gate structures 20, 22, and 24 which have distinct configurations. This Office action will use gate structure 20 for reference.
11 Dielectric layer 38 of Hung is considered a “gate dielectric layer” as it is a dielectric layer in the gate structure between the gate electrode and underlying substrate 12 of Hung.
12 Although the text of Hung does not use the term ‘electrode’, metal layer 40 of Hung is a conductor within the gate structure used to establish electrical contact with the underlying substrate 12 of Hung and is, therefore, considered a “gate electrode”.
13 Although Hung does not explicitly spell out a combination of copper and aluminum, a person of ordinary skill in the art, reading Hung, would at once envisage the claimed combination. (MPEP 2131.02(III) citing Kennametal, Inc. v. Ingersoll Cutting Tool Co., 780 F.3d 1376, 1381, 114 USPQ2d 1250, 1254 (Fed. Cir. 2015). “Kennametal addresses whether the disclosure of a limited number of combination possibilities discloses one of the possible combinations.” (MPEP 2131.02(III)) In Kennametal, the prior art disclosed five binding agents and three coating techniques, resulting in 3x5 = 15 possible combinations, one of which read upon the claim limitation. Similar to the facts of Kennametal, Hung discloses only 15 possible combinations for the alloy layer 42 (four individual options and “any combination thereof” yields fifteen total possible combinations which are, specifically, the four individual compositions of Cu, Al, TiAl, or CoWP (¶ 0020 of Hung); the six compositions consisting of exactly two materials of the four possible materials; the four compositions consisting of exactly three of the materials; and the one composition which consists of all four materials). As such, the disclosure of Hung anticipates a combination of copper and aluminum.
14 The Examiner notes that this surface is a surface of an object that faces upwards and would be seen if looking down from directly above and, therefore, may be considered a “top surface”, even though it is not a “topmost surface”. Were Applicant to amend the claim to require this surface to be a “topmost surface”, this rejection would be overcome.
15 The Examiner notes that this surface is a surface of an object that faces upwards and would be seen if looking down from directly above and, therefore, may be considered a “top surface”, even though it is not a “topmost surface”. Were Applicant to amend the claim to require this surface to be a “topmost surface”, this rejection would be overcome.
16 The Examiner notes that Applicant’s usage of contact resistance is material dependent and relatively high for work function metals (¶ 0039 of Applicant’s Specification as originally filed).
17 This specific rejection of claim 1 will hereinafter be referenced as the “second alternative rejection of claim 1”.
18 The Examiner notes that ‘structure’, as the term is used by Applicant, does not require that it consists of only a single component but, instead, may consist of multiple distinct components. Further, the Examiner notes that “metal gate structure” does not require the structure to consist only of metals, as claim 1 requires the “metal gate structure” to also comprise a dielectric layer.
19 Figs. 1 and 7 of Hung show gate structures 20, 22, and 24 which have distinct configurations. This Office action will use gate structure 20 for reference.
20 Dielectric layer 38 of Hung is considered a “gate dielectric layer” as it is a dielectric layer in the gate structure between the gate electrode and underlying substrate 12 of Hung.
21 Although the text of Hung does not use the term ‘electrode’, metal layer 40 of Hung is a conductor within the gate structure used to establish electrical contact with the underlying substrate 12 of Hung and is, therefore, considered a “gate electrode”.
22 The Examiner notes that a “layer” is interpreted as allowing for the inclusion of a plurality of sub-layers.
23 The Examiner notes that a “layer” is interpreted as allowing for the inclusion of a plurality of sub-layers. Further, an “alloy” layer is interpreted as allowing for the inclusion of additional sub-components which are not alloys, similar to, as discussed above, Applicant’s “metal gate structure” which allows for the inclusion of additional sub-components which are not metals as Applicant’s metal gate structure is required to also include a dielectric layer.
24 The Examiner notes that this surface is a surface of an object that faces upwards and would be seen if looking down from directly above and, therefore, may be considered a “top surface”, even though it is not a “topmost surface”. Were Applicant to amend the claim to require this surface to be a “topmost surface”, this rejection would be overcome.
25 The Examiner notes that this surface is a surface of an object that faces upwards and would be seen if looking down from directly above and, therefore, may be considered a “top surface”, even though it is not a “topmost surface”. Were Applicant to amend the claim to require this surface to be a “topmost surface”, this rejection would be overcome.
26 The Examiner notes that ‘structure’, as the term is used by Applicant, does not require that it consists of only a single component but, instead, may consist of multiple distinct components. Further, the Examiner notes that “metal gate structure” does not require the structure to consist only of metals, as, for example, claim 1 requires the “metal gate structure” to also comprise a dielectric layer.
27 Figs. 1 and 7 of Hung show gate structures 20, 22, and 24 which have distinct configurations. This Office action will use gate structure 20 for reference.
28 The Examiner notes that a “layer” is interpreted as allowing for the inclusion of a plurality of sub-layers. Further, an “alloy” layer is interpreted as allowing for the inclusion of additional sub-components which are not alloys, similar to, as discussed above, Applicant’s “metal gate structure” which allows for the inclusion of additional sub-components which are not metals as Applicant’s metal gate structure is required to also include a dielectric layer.
29 Although Hung does not explicitly spell out a combination of CoWP and TiAl, a person of ordinary skill in the art, reading Hung, would at once envisage the combination. (MPEP 2131.02(III) citing Kennametal, Inc. v. Ingersoll Cutting Tool Co., 780 F.3d 1376, 1381, 114 USPQ2d 1250, 1254 (Fed. Cir. 2015). “Kennametal addresses whether the disclosure of a limited number of combination possibilities discloses one of the possible combinations.” (MPEP 2131.02(III)) In Kennametal, the prior art disclosed five binding agents and three coating techniques, resulting in 3x5 = 15 possible combinations, one of which read upon the claim limitation. Similar to the facts of Kennametal, Hung discloses only 15 possible combinations for the alloy layer 42 (four individual options and “any combination thereof” yields fifteen total possible combinations which are, specifically, the four individual compositions of Cu, Al, TiAl, or CoWP (¶ 0020 of Hung); the six compositions consisting of exactly two materials of the four possible materials; the four compositions consisting of exactly three of the materials; and the one composition which consists of all four materials). As such, the disclosure of Hung anticipates a combination of CoWP and TiAl.
30The examiner notes that “of” is being interpreted in the same manner as ‘comprising’, that is, as allowing for the additional inclusion of non-metallic elements. Further, a “metal film” is interpreted as allowing for the inclusion of additional elements which are not metals, similar to, as discussed above, Applicant’s “metal gate structure” which allows for the inclusion of features which are not metals as Applicant’s metal gate structure is required to also include a dielectric layer.
31This specific rejection of claim 10 will hereinafter be referenced as the “alternative rejection of claim 10”.
32 The Examiner notes that ‘structure’, as the term is used by Applicant, does not require that it consists of only a single component but, instead, may consist of multiple distinct components. Further, the Examiner notes that “metal gate structure” does not require the structure to consist only of metals, as, for example, claim 1 requires the “metal gate structure” to also comprise a dielectric layer.
33 Figs. 1 and 7 of Hung show gate structures 20, 22, and 24 which have distinct configurations. This Office action will use gate structure 20 for reference.
34 The Examiner notes that a “layer” is interpreted as allowing for the inclusion of a plurality of sub-layers. Further, an “alloy” layer is interpreted as allowing for the inclusion of additional sub-components which are not alloys, similar to, as discussed above, Applicant’s “metal gate structure” which allows for the inclusion of additional sub-components which are not metals as Applicant’s metal gate structure is required to also include a dielectric layer.
35 Although Hung does not explicitly spell out a combination of CoWP and TiAl, a person of ordinary skill in the art, reading Hung, would at once envisage the combination. (MPEP 2131.02(III) citing Kennametal, Inc. v. Ingersoll Cutting Tool Co., 780 F.3d 1376, 1381, 114 USPQ2d 1250, 1254 (Fed. Cir. 2015). “Kennametal addresses whether the disclosure of a limited number of combination possibilities discloses one of the possible combinations.” (MPEP 2131.02(III)) In Kennametal, the prior art disclosed five binding agents and three coating techniques, resulting in 3x5 = 15 possible combinations, one of which read upon the claim limitation. Similar to the facts of Kennametal, Hung discloses only 15 possible combinations for the alloy layer 42 (four individual options and “any combination thereof” yields fifteen total possible combinations which are, specifically, the four individual compositions of Cu, Al, TiAl, or CoWP (¶ 0020 of Hung); the six compositions consisting of exactly two materials of the four possible materials; the four compositions consisting of exactly three of the materials; and the one composition which consists of all four materials). As such, the disclosure of Hung anticipates a combination of CoWP and TiAl.
36The examiner notes that “of” is being interpreted in the same manner as ‘comprising’, that is, as allowing for the additional inclusion of non-metallic elements. Further, a “metal film” is interpreted as allowing for the inclusion of additional elements which are not metals, similar to, as discussed above, Applicant’s “metal gate structure” which allows for the inclusion of features which are not metals as Applicant’s metal gate structure is required to also include a dielectric layer.
37 Dielectric layer 38 of Hung is considered a “capping layer” as it forms a cap on the gate dielectric layer of Hung.
38 Although the text of Hung does not use the term ‘electrode’, metal layer 40 of Hung is a conductor within the gate structure used to establish electrical contact with the underlying substrate 12 of Hung and is, therefore, considered a “gate electrode”.
39As shown in Fig. 7 of Hung, the gate electrode 40 sits within the U-shaped capping layer 38 which is considered to satisfy the limitation “over the capping layer” as used by the Applicant as Applicant’s gate electrode 124 in Fig. 4A also sits within the U-shaped capping layer 140 (¶ of Applicant’s Specification as originally filed).
40 The Examiner notes that ‘structure’, as the term is used by Applicant, does not require that it consists of only a single component but, instead, may consist of multiple distinct components. Further, the Examiner notes that “metal gate structure” does not require the structure to consist only of metals, as claim 17 requires the “metal gate structure” to also comprise a dielectric layer.
41 Figs. 1 and 7 of Hung show gate structures 20, 22, and 24 which have distinct configurations. This Office action will use gate structure 20 for reference.
42 Dielectric layer 38 of Hung is considered a “gate dielectric layer” as it is a dielectric layer in the gate structure between the gate electrode and underlying substrate 12 of Hung.
43 Although the text of Hung does not use the term ‘electrode’, metal layer 40 of Hung is a conductor within the gate structure used to establish electrical contact with the underlying substrate 12 of Hung and is, therefore, considered a “gate electrode”.
44 The Examiner notes that a “layer” is interpreted as allowing for the inclusion of a plurality of sub-layers.
45 Although Hung does not explicitly spell out a combination of copper and TiAl, a person of ordinary skill in the art, reading Hung, would at once envisage the claimed combination. (MPEP 2131.02(III) citing Kennametal, Inc. v. Ingersoll Cutting Tool Co., 780 F.3d 1376, 1381, 114 USPQ2d 1250, 1254 (Fed. Cir. 2015). “Kennametal addresses whether the disclosure of a limited number of combination possibilities discloses one of the possible combinations.” (MPEP 2131.02(III)) In Kennametal, the prior art disclosed five binding agents and three coating techniques, resulting in 3x5 = 15 possible combinations, one of which read upon the claim limitation. Similar to the facts of Kennametal, Hung discloses only 15 possible combinations for the alloy layer 42 (four individual options and “any combination thereof” yields fifteen total possible combinations which are, specifically, the four individual compositions of Cu, Al, TiAl, or CoWP (¶ 0020 of Hung); the six compositions consisting of exactly two materials of the four possible materials; the four compositions consisting of exactly three of the materials; and the one composition which consists of all four materials). As such, the disclosure of Hung anticipates a combination of copper and TiAl.
46 The Examiner notes that this surface is a surface of an object that faces upwards and would be seen if looking down from directly above and, therefore, may be considered a “top surface”, even though it is not a “topmost surface”. Were Applicant to amend the claim to require this surface to be a “topmost surface”, this rejection would be overcome.