DETAILED ACTION
The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Applicant's response to the Office Non-Final Action filed on 3/23/2026 is acknowledged.
Applicant amended claims 1, 7, 8, 14, and 19; and cancelled claims 6 and 12.
Applicant added claims 21 and 22.
Claim Objections
At the following locations, indicated by the notation [claim(s), line(s)], please make the following changes to provide better clarity, proper grammar, or proper antecedent basis:
[14, 8] insert "material" after "the first metal nitride".
[14, 12] insert "material" after "the second metal nitride".
[19, 2] insert "of" after "the second layer".
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale, or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1-5, 14-16, 19, 21, and 22 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Wang et al. (US 2019/0378907) (hereafter Wang).
Regarding claim 1, Wang discloses a device comprising:
a gate stack (111, 112, 113, 121, 122, 131, 132, 142, and 140 in Fig. 9B) over an active region of a substrate 100 (Fig. 9B, paragraph 0054), wherein the gate stack (111, 112, 113, 121, 122, 131, 132, 142, and 140 in Fig. 9B) comprises:
a gate dielectric layer (112 and 113 in Fig. 9B, paragraph 0060);
a first work function layer (121, 122, and 132 in Fig. 9B) over the gate dielectric layer (112 and 113 in Fig. 9B), the first work function layer (121, 122, and 132 in Fig. 9B) comprising a plurality of first layers (121 and 132 in Fig. 9B) and a plurality of second layers 122 (Fig. 9B, paragraph 0056) arranged in an alternating manner over the gate dielectric layer (112 and 113 in Fig. 9B), each of the plurality of first layers (121 and 132 in Fig. 9B) comprising a first material (see paragraph 0056, wherein “TiN”; and see paragraph 0015, wherein “TiN”), each of the plurality of second layers 122 (Fig. 9B) comprising a second material (see paragraph 0056, wherein “TaN”) different from the first material (see paragraph 0056, wherein “TiN”; and see paragraph 0015, wherein “TiN”), wherein a first one (bottom 121 in Fig. 9B) of the plurality of first layers (121 and 132 in Fig. 9B) of the first workfunction layer (121, 122, and 132 in Fig. 9B) interfaces the gate dielectric layer (112 and 113 in Fig. 9B): and
a second workfunction layer 131 (Fig. 9B, paragraph 0063) interfacing a second one 132 (Fig. 9B) of the plurality of first layers (121 and 132 in Fig. 9B) of the first workfunction layer (121, 122, and 132 in Fig. 9B), the second workfunction layer 131 (Fig. 9B, paragraph 0063; and see paragraph 0015, wherein “TiAl”) comprising a third material different from the first material (see paragraph 0056, wherein “TiN”; and see paragraph 0015, wherein “TiN”) and the second material (see paragraph 0056, wherein “TaN”).
Regarding claim 2, Wang further discloses the device of claim 1, wherein the first material (see paragraph 0056, wherein “TiN”; and see paragraph 0015, wherein “TiN”) is a first metal nitride material.
Regarding claim 3, Wang further discloses the device of claim 2, wherein the first metal nitride material (see paragraph 0056, wherein “TiN”; and see paragraph 0015, wherein “TiN”) comprises TaN or TiN.
Regarding claim 4, Wang further discloses the device of claim 2, wherein the second material (see paragraph 0056, wherein “TaN”) is a second metal nitride material.
Regarding claim 5, Wang further discloses the device of claim 4, wherein the second metal nitride material (see paragraph 0056, wherein “TaN”) comprises TaN or TiN.
Regarding claim 14, Wang discloses a device comprising:
a first active region 100 (Fig. 9B, paragraph 0054, wherein “semiconductor substrate”) of a semiconductor material;
a first transistor (see “P-type transistors” in paragraph 0059) on the first active region 100 (Fig. 9B), the first transistor being p-type, the first transistor (see “P-type transistors” in paragraph 0059) comprising a first gate stack (region from 111 to 140 in Fig. 9B), the first gate stack comprising:
a gate dielectric layer 112 (Fig. 9B, paragraph 0060);
a first layer (bottom 121 in Fig. 9B, paragraph 0056) of a first metal nitride material (see paragraph 0056, wherein “TiN”) over the gate dielectric layer 112 (Fig. 9B);
wherein the first layer (bottom 121 in Fig. 9B) of the first metal nitride material has a first thickness (horizontal length of bottom 121 in Fig. 9B) measured between opposing sidewalls of the first layer (bottom 121 in Fig. 9B) of the first metal nitride;
a first layer (bottom 122 in Fig. 9B, paragraph 0056) of a second metal nitride material (see paragraph 0056, wherein “TaN”) over the first layer (bottom 121 in Fig. 9B) of the first metal nitride material (see paragraph 0056, wherein “TiN”), the first metal nitride material (see paragraph 0056, wherein “TiN”) being a different material than the second metal nitride material (see paragraph 0056, wherein “TaN”), wherein the first layer (bottom 122 in Fig. 9B) of the second metal nitride material has a second thickness (horizontal length of bottom 122 in Fig. 9B) measured between opposing sidewalls of the first layer (bottom 122 in Fig. 9B) of the second metal nitride, and wherein the first thickness (horizontal length of bottom 121 in Fig. 9B) is different than the second thickness horizontal length of bottom 122 in Fig. 9B);
a second layer (top 121 in Fig. 9B, paragraph 0056) of the first metal nitride material (see paragraph 0056, wherein “TiN”) over the first layer (bottom 122 in Fig. 9B) of a second metal nitride material (see paragraph 0056, wherein “TaN”);
a second layer (top 122 in Fig. 9B, paragraph 0056) of the second metal nitride material (see paragraph 0056, wherein “TaN”) over the second layer (top 121 in Fig. 9B) of the first metal nitride material (see paragraph 0056, wherein “TiN”); and
a conductive fill layer 140 (Fig. 9B, paragraph 0095) over the second layer (top 122 in Fig. 9B) of the second metal nitride material (see paragraph 0056, wherein “TaN”).
Regarding claim 15, Wang further discloses the device of claim 14, wherein the first metal nitride material (see paragraph 0056, wherein “TiN”) comprises TaN or TiN.
Regarding claim 16, Wang further discloses the device of claim 15, wherein the second metal nitride material (see paragraph 0056, wherein “TaN”) comprises TaN or TiN.
Regarding claim 19, Wang further discloses the device of claim 14, wherein the first layer (bottom 121 in Fig. 9B) of the first metal nitride material, the first layer (bottom 122 in Fig. 9B) of the second metal nitride material, the second layer (top 121 in Fig. 9B) the first metal nitride material, and the second layer (top 122 in Fig. 9B) of the second metal nitride material are collectively comprised by a p-type work function metal layer (see paragraph 0015, wherein “P-type work function layer”), and wherein the device further comprises an n-type work function metal layer 131 (Fig. 9B, paragraph 0063) between the second layer (top 122 in Fig. 9B) of the second metal nitride material (see paragraph 0056, wherein “TaN”) and the conductive fill layer 140 (Fig. 9B).
Regarding claim 21, Wang further discloses the device of claim 19, wherein
a second active region 100 (Fig. 9A, paragraph 0054, wherein “semiconductor substrate”) of a semiconductor material;
a second transistor (see “N-type transistors” in paragraph 0059) on the second active region 100 (Fig. 9A), the second transistor being n-type, the first transistor (see “N-type transistors” in paragraph 0059) comprising a second gate stack (region from 111 to 140 in Fig. 9A), the second gate stack comprising:
a second gate dielectric layer (112 and 113 in Fig. 9A, paragraph 0060);
a second n-type work function metal (region from bottom 121 to 142 in Fig. 9A) interfacing the second dielectric layer (112 and 113 in Fig. 9A); and
a second conductive fill layer 140 (Fig. 9A, paragraph 0064) over the second n-type work function metal layer (region from bottom 121 to 142 in Fig. 9A).
Regarding claim 22, Wang further discloses the device of claim 14, wherein the second layer (top 121 in Fig. 9B) of the first metal nitride material has the first thickness (horizontal length of top 121 in Fig. 9B), and wherein the second layer (top 122 in Fig. 9B) of the second metal nitride material has the second thickness (horizontal length of top 122 in Fig. 9B) that is different from the first thickness (horizontal length of top 121 in Fig. 9B).
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102 of this title, 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.
Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Wang as applied to claim 1 above, and further in view of Zhao et al. (US 2015/0243564) (hereafter Zhao).
Regarding claim 7, Wang discloses the device of claim 1, however Wang does not disclose the first work function layer is a p-type work function layer, and wherein the second work function layer is an n-type work function layer.
Zhao discloses the first work function layer 204A (Fig. 2K, paragraph 0093) is a p-type work function layer, and wherein the second work function layer 205A (Fig. 2K, paragraph 0098) is an n-type work function layer.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Wang to form the first work function layer is a p-type work function layer, and wherein the second work function layer is an n-type work function layer, as taught by Zhao, in order to satisfy work function requirements associated with the device.
Claims 17 and 18 are rejected under 35 U.S.C. 103 as being unpatentable over Wang as applied to claim 16 above.
Regarding claim 17, Wang further discloses the device of claim 16, wherein the first layer (bottom 121 in Fig. 9B) of the first metal nitride material (see paragraph 0056, wherein “TiN”), the first layer (bottom 122 in Fig. 9B) of the second metal nitride material (see paragraph 0056, wherein “TaN”), the second layer (top 121 in Fig. 9B) the first metal nitride material, and the second layer (top 122 in Fig. 9B) of the second metal nitride material are collectively comprised by a p-type work function metal layer.
Wang does not explicitly disclose a ratio of a fraction of Ta to a fraction of Ti in the p-type work function metal layer is 0.5 to 0.95.
Regarding the limitation, “a ratio of a fraction of Ta to a fraction of Ti in the p-type work function layer is from 0.5 to 0.95”, Wang discloses the pair of layers (121 and 122 in Fig. 9B) comprising a first layer 121 (Fig. 9B, paragraph 0056) comprising a first metal nitride material (see paragraph 0056, wherein “TiN”) and a second layer 122 (Fig. 9B, paragraph 0056) comprising a second metal nitride material (see paragraph 0056, wherein “TaN”). Ratio of Ta in a portion of second layer 122 (Wang, Fig. 9B, paragraph 0056, wherein “TaN”) to Ti in portion of the first layer 121 (Wang, Fig. 9B, paragraph 0056, wherein “TiN”) having twice the size of the portion of second layer 122 (Wang, Fig. 9B) is 0.5. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Wang to form a ratio of a fraction of Ta to a fraction of Ti in the p-type work function layer is from 0.5 to 0.95, since such a modification would have involved discovering the optimum or working ranges involves only routine skill in the art. In re Aller, 220 F.2d 454,456, 105 USPQ 233,235 (CCPA 1955). In addition, in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). Note that the specification contains no disclosure of either the critical nature of the claimed ranges or any unexpected results arising therefrom. Where patentability is said to be based upon particular chosen dimensions or upon another variable recited in a claim, the applicant must show that the chosen dimensions are critical. In re Woodruff, 919 f.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990).
Regarding claim 18, Wang discloses the device of claim 17, however Wang does not explicitly disclose the fraction of Ta in the p-type work function metal layer is 7 at% to 40 at%, and the fraction of Ti in the p-type work function metal layer is 7 at% to 40 at%.
Regarding the limitation, “the fraction of Ta in the p-type work function metal layer is 7 at% to 40 at%, and the fraction of Ti in the p-type work function metal layer is 7 at% to 40 at%”, Wang discloses the pair of layers (121 and 122 in Fig. 9B) comprising a first layer 121 (Fig. 9B, paragraph 0056) comprising a first metal nitride material (see paragraph 0056, wherein “TiN”) and a second layer 122 (Fig. 9B, paragraph 0056) comprising a second metal nitride material (see paragraph 0056, wherein “TaN”). A portion of first layer 121 (Wang, Fig. 9B, paragraph 0056, wherein “TiN”) has Ti:N = 1:1 and a portion of second layer 122 (Wang, Fig. 9B, paragraph 0056, wherein “TaN”) has Ta:N = 1:1 such that the fraction of Ta in the sum of the portion of first layer 121 (Wang, Fig. 9B) and the portion of first layer 121 (Wang, Fig. 9B) is 25 at% (Ta:TiN/TaN = 1:4). It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Wang to form the fraction of Ta in the p-type work function metal layer is 7 at% to 40 at%, and the fraction of Ti in the p-type work function metal layer is 7 at% to 40 at%, since such a modification would have involved discovering the optimum or working ranges involves only routine skill in the art. In re Aller, 220 F.2d 454,456, 105 USPQ 233,235 (CCPA 1955). In addition, in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). Note that the specification contains no disclosure of either the critical nature of the claimed ranges or any unexpected results arising therefrom. Where patentability is said to be based upon particular chosen dimensions or upon another variable recited in a claim, the applicant must show that the chosen dimensions are critical. In re Woodruff, 919 f.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990).
Claim 20 is rejected under 35 U.S.C. 103 as being unpatentable over Wang as applied to claim 19 above, and further in view of Chan et al. (US 2011/0241130) (hereafter Chan).
Regarding claim 20, Wang discloses the device of claim 19, however Wang does not disclose a glue layer between the work function metal and the conductive fill layer.
Chan discloses a glue layer 116 (Fig. 1, paragraph 0025) between the work function metal 112 (Fig. 1, paragraph 0015) and the conductive fill layer 118 (Fig. 1, paragraph 0025).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Wang to form a glue layer between the work function metal and the conductive fill layer, as taught by Chan, since a wetting layer/glue layer 116 (Chan, Fig. 1, paragraph 0025) is formed immediately below the cap layer/conductive fill layer 118 (Chan, Fig. 1, paragraph 0025) to enhance adhesion of the cap layer/conductive fill layer 118 (Chan, Fig. 1, paragraph 0025) to the underlying layer.
Claims 8-11 and 13 are rejected under 35 U.S.C. 103 as being unpatentable over Wang et al. (US 2019/0378907) (hereafter Wang), in view of Chan et al. (US 2011/0241130) (hereafter Chan).
Regarding claim 8, Wang discloses a device comprising:
a gate stack (111, 112, 113, 121, 122, 131, 132, 142, and 140 in Fig. 9B) of a p-type device (see paragraph 0032, wherein “P-type transistors”) over an active region of a substrate 100 (Fig. 9B, paragraph 0054), wherein the gate stack (111, 112, 113, 121, 122, 131, 132, 142, and 140 in Fig. 9B) comprises:
a gate dielectric layer 112 (Fig. 9B, paragraph 0060);
a p-type work function layer (121 and 122 in Fig. 9B) over the gate dielectric layer 112 (Fig. 9B), the p-type work function layer (121 and 122 in Fig. 9B) comprising a pair of layers (121 and 122 in Fig. 9B) repeated two of more times, the pair of layers (121 and 122 in Fig. 9B) comprising a first layer 121 (Fig. 9B, paragraph 0056) comprising a first metal nitride material (see paragraph 0056, wherein “TiN”) and a second layer 122 (Fig. 9B, paragraph 0056) comprising a second metal nitride material (see paragraph 0056, wherein “TaN”) different from the first metal nitride material (see paragraph 0056, wherein “TiN”); and
an n-type work function layer 131 (Fig. 9B, paragraph 0063) over the p-type work function layer (121 and 122 in Fig. 9B).
Wang does not disclose a glue layer over the n-type work function layer; and
a fill metal over the glue layer, wherein the glue layer extends continuously from the n-type work function layer to the fill metal.
Chan discloses a glue layer 116 (Fig. 1, paragraph 0025) over the n-type work function layer 112 (Fig. 1, paragraph 0021, wherein “n-type metal work function layer”); and
a fill metal 118 (Fig. 1, paragraph 0025) over the glue layer 116 (Fig. 1), wherein the glue layer 116 (Fig. 1) extends continuously from the n-type work function layer 112 (Fig. 1) to the fill metal 118 (Fig. 1).
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Wang to form a glue layer over the n-type work function layer; and a fill metal over the glue layer, wherein the glue layer extends continuously from the n-type work function layer to the fill metal, as taught by Chan, since a wetting layer/glue layer 116 (Chan, Fig. 1, paragraph 0025) is formed immediately below the cap layer/conductive fill layer 118 (Chan, Fig. 1, paragraph 0025) to enhance adhesion of the cap layer/conductive fill layer 118 (Chan, Fig. 1, paragraph 0025) to the underlying layer.
Regarding claim 9, Wang further discloses the device of claim 8, wherein the first metal nitride material (see paragraph 0056, wherein “TiN”) comprises TaN or TiN.
Regarding claim 10, Wang further discloses the device of claim 9, wherein the second metal nitride material (see paragraph 0056, wherein “TaN”) comprises TaN or TiN.
Regarding claim 11, Wang in view of Chan discloses the device of claim 10, however Wang does not explicitly disclose a ratio of a fraction of Ta to a fraction of Ti in the p-type work function layer is from 0.5 to 0.95.
Regarding the limitation, “a ratio of a fraction of Ta to a fraction of Ti in the p-type work function layer is from 0.5 to 0.95”, Wang discloses the pair of layers (121 and 122 in Fig. 9B) comprising a first layer 121 (Fig. 9B, paragraph 0056) comprising a first metal nitride material (see paragraph 0056, wherein “TiN”) and a second layer 122 (Fig. 9B, paragraph 0056) comprising a second metal nitride material (see paragraph 0056, wherein “TaN”). Ratio of Ta in a portion of second layer 122 (Wang, Fig. 9B, paragraph 0056, wherein “TaN”) to Ti in portion of the first layer 121 (Wang, Fig. 9B, paragraph 0056, wherein “TiN”) having twice the size of the portion of second layer 122 (Wang, Fig. 9B) is 0.5. It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to modify the invention of Wang to form a ratio of a fraction of Ta to a fraction of Ti in the p-type work function layer is from 0.5 to 0.95, since such a modification would have involved discovering the optimum or working ranges involves only routine skill in the art. In re Aller, 220 F.2d 454,456, 105 USPQ 233,235 (CCPA 1955). In addition, in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990). Note that the specification contains no disclosure of either the critical nature of the claimed ranges or any unexpected results arising therefrom. Where patentability is said to be based upon particular chosen dimensions or upon another variable recited in a claim, the applicant must show that the chosen dimensions are critical. In re Woodruff, 919 f.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990).
Regarding claim 13, Wang further discloses the device of claim 8, wherein a first thickness (vertical length of bottom 121 in Fig. 9B) of the first layer 121 (Fig. 9B) is different from a second thickness (vertical length of top 121 in Fig. 9B) of the second layer 122 (Fig. 9B).
Response to Arguments
1. Applicant's arguments filed 3/23/2026 have been fully considered.
2. Applicant's arguments with respect to claims 1-5, 7-11, and 13-22 have been considered but are moot in view of the new ground(s) of rejection.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any extension fee pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the date of this final action.
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/L.B.K/Examiner, Art Unit 2813
/STEVEN B GAUTHIER/Supervisory Patent Examiner, Art Unit 2813
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