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 .
Response to Amendment
Amendment filed on 12/01/2025 is acknowledged. Claims 1, 6, 10-11, 13, 17-18 have been amended. Claim 8 has been canceled. Claim 21 is added.
Response to Arguments
Applicant’s arguments with respect to claims 1-7, 9 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-7, 9, 21 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 1 recites “having a dopant concentration less than about 5 x 1013 atoms/cm2” in line 4 of claim 1. Typically, the unit for dopant concentration to be atoms/cm3 in the art. It is unclear how the dopant concentration is measured in the claim (and also the specification) in order to have the unit “atom/cm2”. For the purpose of examination, it is interpreted this is a typographical error and that the actual unit is “atoms/cm3”.
Claims 2-7, 9 and 21 are dependent on claim 1, thus, inherit the indefiniteness issue of claim 1.
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 1-3, 7, 9 are rejected under 35 U.S.C. 103 as being unpatentable over Tsai et al. (US 10304835 B1) in view of Chen et al. (US 2019/0318967 A1).
Regarding claim 1, Tsai teaches a semiconductor device (device in Figs. 25-27 of Tsai), comprising:
a fin structure (58 in Fig. 1) on a substrate (50);
an interfacial layer (100) on the fin structure, wherein a top portion (as shown in Fig. 24, the dopant is mainly at the interface of the interfacial layer 100 and the gate dielectric layer 102) of the interfacial layer comprises a metal dopant (as stated in column 2 lines 15-16, the dipole-inducing element is one of the metals such as La, Al…);
a high-k dielectric layer (102) on the top portion of the interfacial layer and comprising a high-k dielectric material (102 is a high-k dielectric material, as stated in column 8 lines 30-35 of Tsai); and
an intermixing layer (when the high-k dielectric layer 102 and capping 116 undergo thermal annealing process as described in column 11 lines 2-12, atoms of these layers inter-diffuse into each other at the interface to form an intermixing layer. This is a natural occurring phenomenon at high temperature) on the high-k dielectric layer, wherein the intermixing layer is a mixture of the high-k dielectric layer and a diffusion barrier layer (capping layer 116) comprising nitrogen (116 is similar to 112, which is TiN, as described in column 10 lines 13-17 and 65-67).
But Tsai does not teach that the metal dopant having a dopant concentration less than about 5 x 1013 atoms/cm2 (please see interpretation in 112b rejection above).
Chen teaches that typical dipole dopant concentration is in the range of 1x1012 atoms/cm3 to about 1x1022 atoms/cm3 (see [0050] of Chen).
Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have formed the dopant having dopant concentration of 1x1012 atoms/cm3 to about 1x1022 atoms/cm3 since this is a known range of dipole dopant concentration.
As incorporated, since the claimed ranges of “less than about 5 x 1013 atoms/cm2” overlaps or lie inside ranges disclosed by the prior art of 1x1012 atoms/cm3 to about 1x1022 atoms/cm3, a prima facie case of obviousness exists. Therefore, it would have been obvious at the effective filing date of the claimed invention to a person having ordinary skill in the art to have made the dopant concentration less than about 5 x 1013 atoms/cm3. See 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); and In re Geisler, 116 F.3d 1465, 1469-71, 43 USPQ2d 1362, 1365-66 (Fed. Cir. 1997).
Regarding claim 2, Tsai in view of Chen teaches all limitations of the semiconductor device of claim 1, and also teaches wherein a bottom portion of the high-k dielectric layer adjacent to the top portion of the interfacial layer comprises the metal dopant (as shown in Fig. 20 of Tsai), and wherein the metal dopant forms a dopant dipole at an interface of the interfacial layer and the high-k dielectric layer (as described in column 10 lines 1-4 of Tsai).
Regarding claim 3, Tsai in view of Chen teaches all limitations of the semiconductor device of claim 2, and also teaches wherein a ratio of a thickness of the bottom portion of the high-k dielectric layer to a thickness of the high-k dielectric layer ranges from about 0.03 to about 0.4 (as written, there is no specific requirements on how the bottom portion of the high-k dielectric layer is defined. For example, a bottom third portion of the high-k dielectric layer can be defined as the bottom portion of claim 2).
Regarding claim 7, Tsai in view of Chen teaches all limitations of the semiconductor device of claim 1, and further comprising a gate electrode (118 in Fig. 25 of Tsai) on the intermixing layer.
Regarding claim 9, Tsai in view of Chen teaches all limitations of the semiconductor device of claim 1, and also teaches wherein the intermixing layer comprises the high-k dielectric material, nitrogen, and at least one of titanium, tantalum, and aluminum (from the claim 1 above, this intermixing layer includes TiN and high-k dielectric material).
Claims 4-5 and 8 are rejected under 35 U.S.C. 103 as being unpatentable over Tsai in view of Chen, and further in view of Wang (US 2020/0357700 A1).
Regarding claim 4, Tsai in view of Chen teaches all limitations of the semiconductor device of claim 2, but does not explicitly teach wherein a concentration of the metal dopant in the bottom portion of the high-k dielectric layer ranges from about 2 atomic percent to about 55 atomic percent.
Wang teaches a semiconductor device (200 in Fig. 2D of Wang) with a dipole layer underneath the high-k dielectric layer (see stacks 240-242 in Fig. 2D of Wang). Wang also teaches that the atomic percentage of the components in the dipole material layer can be varied to tailor the shift in threshold voltage (see [0019] of Wang). Thus, Wang teaches that the atomic percentage of the elements is a result effective variable.
Therefore it would have been obvious at the effective filing date of the claimed invention to a person having ordinary skill in the art to modified the concentration of the metal dopant in the bottom portion of the high-k dielectric layer to range from about 2 atomic percent to about 55 atomic percent in order to have the appropriate threshold voltage for the device, since it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art (In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980)).
Regarding claim 5, Tsai in view of Chen teaches all limitations of the semiconductor device of claim 2, but does not teach explicitly wherein a ratio of a thickness of the top portion of the interfacial layer to a thickness of the interfacial layer ranges from about 0.03 to about 0.6.
Wang teaches a semiconductor device (200 in Fig. 2D of Wang) with a dipole layer (212C/212D) underneath the high-k dielectric layer (see stacks 244-246 in Fig. 2D of Wang). Wang also teaches that the thickness of the dipole layer can be varied to tailor the shift in threshold voltage (see [0020] of Wang). Thus, Wang teaches that the thickness of the dipole layer is a result effective variable.
Therefore it would have been obvious at the effective filing date of the claimed invention to a person having ordinary skill in the art to modified the thickness of the top portion of the interfacial layer to a thickness of the interfacial layer ranges from about 0.03 to about 0.6 in order to have the appropriate threshold voltage for the device, since it has been held that discovering an optimum value of a result effective variable involves only routine skill in the art (In re Boesch, 617 F.2d 272, 205 USPQ 215 (CCPA 1980)).
Allowable Subject Matter
Claims 6 and 21 would be allowable if rewritten to overcome the rejection(s) under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), 2nd paragraph, set forth in this Office action and to include all of the limitations of the base claim and any intervening claims.
Claims 10-20 are allowed.
The following is a statement of reasons for the indication of allowable subject matter:
Regarding claim 6, the prior art of record does not disclose or fairly suggest a semiconductor device comprising: “the diffusion barrier layer on the intermixing layer, wherein the diffusion barrier layer comprises the metal dopant; and a gate electrode on the diffusion barrier layer” along with other limitations of claim 1.
Regarding claim 10, the prior art of record does not disclose or fairly suggest a semiconductor device comprising: “the first diffusion barrier layer on the first intermixing layer, wherein the first diffusion barrier layer has a first thickness; and the second diffusion barrier layer on the second intermixing layer, wherein the second diffusion barrier layer has a second thickness different from the first thickness” along with other limitations of the claim 10.
Regarding claim 17, the prior art of record does not disclose or fairly suggest a semiconductor device, comprising: “a first interfacial layer on a first fin structure, wherein the first interfacial layer comprises a first undoped portion and a first top portion doped with a dopant, and wherein the first interfacial layer has a first thickness and the first top portion has a second thickness” and “a second interfacial layer on a second fin structure, wherein the second interfacial layer comprises a second undoped portion and a second top portion doped with the dopant, and wherein the second interfacial layer has the first thickness and the second top portion has a third thickness different from the second thickness” along with other limitations of the claim.
Regarding claim 21, the prior art of record does not disclose or fairly suggest a semiconductor device satisfying the limitation “wherein: the interfacial layer further comprises an undoped bottom portion; the top portion has a first thickness; and the undoped bottom portion has a second thickness greater than the first thickness” along with other limitations of claim 1.
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 nonprovisional extension fee (37 CFR 1.17(a)) 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 mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to TUAN A HOANG whose telephone number is (571)270-0406. The examiner can normally be reached Monday-Friday 8-9am, 10am-6pm EST.
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/Tuan A Hoang/ Primary Examiner, Art Unit 2898
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