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 .
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.
Claim(s) 11-13, 21, 23-24, and 26-29, 36-37 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yang (Pub. No.: US 2020/0135655) in view of another Yang (Patent No.: US 10651279) (hereinafter `279).
Re claim 11, Yang, FIGS. 1A-1G teaches a method, comprising:
forming a transistor on a substrate (“semiconductor substrate”, ¶ [0012]);
forming a source/drain contact (104, [0013]) on a source/drain region of the transistor;
forming a first dielectric layer (102) over the source/drain contact;
etching the first dielectric layer to form a first opening (101, FIG. 1A) exposing the source/drain contact;
growing a first graphene layer (114, FIG. 1D, [0038]) over the first dielectric layer and in the opening at a temperature in a range from about 300 ºC to 400 ºC (temperature within a range of about 200-1200 ºC);
forming a first metal line (120, FIG. 1F) in the first opening of the first dielectric layer such that the first graphene layer (114) is disposed between the first metal line (120) and a sidewall of the first dielectric layer (102) and between the first metal line (120) and the source/drain contact (104).
Re claim 21, Yang, FIGS. 1A-1G teaches a method of forming a semiconductor device, comprising:
forming a transistor on a substrate (“semiconductor substrate”);
forming a source/drain contact (104) on a source/drain region of the transistor;
forming a first dielectric layer (102) over the source/drain contact;
etching the first dielectric layer (101, FIG. 1A) to form a first opening exposing the source/drain contact;
growing a first graphene layer (114, FIG. 1D) over the first dielectric layer and in the first opening, wherein growing the first graphene layer comprises:
generating carbon atoms by dissociating a carbon-containing gas (“a carbon dissolution process 116 is applied, as shown in FIG. 1D. The carbon dissolution process 112 causes carbon atoms from the carbon layer 110 to migrate to the dielectric layer 102”, [0021]); and
adsorbing the carbon atoms on a surface of the first dielectric layer (“the carbon layer 110 to migrate to the dielectric layer 102”);
forming a first metal line (120, FIG. 1F) in the first opening of the first dielectric layer, such that the first graphene layer (114) is disposed between the first metal line (120) and a sidewall of the first dielectric layer (102) and between the first metal line (120) and the source/drain contact (104).
In re claims 11 and 21, Yang fails to teach depositing a second dielectric layer over the first metal line; etching the second dielectric layer to form a second opening exposing the first metal line, wherein the second opening is formed as a stepped sidewall structure having an upper sidewall, a lower sidewall laterally set back from the upper sidewall, and a horizontal surface connecting the lower sidewall to the upper sidewall; growing a second graphene layer to line the lower sidewall, the upper sidewall, and the horizontal surface of the second opening; and filling the second opening with a second metal line.
`279 teaches depositing a second dielectric layer (608, FIG. 6, refers to FIGS. 2-5 for method) over the first metal line (403);
etching the second dielectric layer (608) to form a second opening exposing the first metal line (403), wherein the second opening is formed as a stepped sidewall structure having an upper sidewall, a lower sidewall laterally set back from the upper sidewall, and a horizontal surface connecting the lower sidewall to the upper sidewall;
growing a second graphene layer (606, col. 14, lines 55-87) to line the lower sidewall, the upper sidewall, and the horizontal surface of the second opening; and
filling the second opening with a second metal line (602, col. 15, lines 1-5).
It would have been obvious for a person of ordinary skill in the art before the effective filing date of the claim invention to include the above said teaching for the purpose of reducing voids formed within dual damascene metal layers as taught by `279, col. 15, lines 5-18.
Re claim 12, Yang, FIGS. 1A-1G teaches the method of claim 11, wherein growing the first graphene layer comprises: introducing carbon atoms to the first dielectric layer at a temperature in a range from about 300 ºC to 400 ºC (temperature within a range of about 200-1200 ºC).
Re claim 13, Yang, FIGS. 1A-1G teaches the method of claim 11, wherein growing the first graphene layer is performed under a pressure in a range from about 1 Torr to about 20 Torr (“0.25 torr-30 atm”, [0038]).
Re claim 23, Yang, FIGS. 1A-1G teaches the method of claim 21, wherein dissociating the carbon-containing gas is performed at a temperature in a range from about 2000 ºC to 3000 ºC (temperature within a range of about 200-1200 ºC).
Re claim 24, Yang, FIGS. 1A-1G teaches the method of claim 21, wherein growing the first graphene layer is performed under a pressure in a range from about 1 Torr to about 20 Torr (“0.25 torr-30 atm”).
Re claim 26, Yang, FIGS. 1A-1G teaches the method of claim 21, wherein the first graphene layer is grown through an epitaxial growth process to form a crystalline film (“The annealing process may be applied at a temperature within a range of about 200-1200 ºC, [0022]).
Re claim 27, Yang, FIGS. 1A-1G teaches the method of claim 21, wherein growing the first graphene layer comprises: heating the first dielectric layer to a temperature in a range from about 300 ºC to 400 ºC (temperature within a range of about 200-1200 ºC).
Re claim 28, Yang, FIGS. 1A-1G teaches the method of claim 21, wherein the first dielectric layer comprises silicon oxide, silicon nitride (102, [0012]), or combinations thereof.
Re claim 29, Yang, FIGS. 1A-1G teaches the method of claim 21, further comprising: performing a chemical mechanical polishing (CMP) process to remove excessive portions of the filling metal and the graphene layer until a top surface of the dielectric layer is exposed (FIG. 1G, [0028]); and after the combining of Yang and `279 would teach after forming the first metal line and before depositing the second dielectric layer.
Re claim 36, in the combination, `279, FIG. 6 teaches the method of claim 11, wherein the second graphene layer (606) comprises a portion disposed between the first metal line (403) and the second metal line (602).
Re claim 37, in the combination, `279, FIG. 6 teaches the method of claim 21, wherein the second graphene layer (606) comprises a portion disposed between the first metal line (403) and the second metal line (602).
Claim(s) 14, 25 and 35 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yang/`279.
In re claims 14, 25 and 35, Yang differs from the claim invention by not disclosing wherein a time-to-breakdown of the first graphene layer in time dependent dielectric breakdown (TDDB) measurement is greater than about 50 seconds (claim 14).
wherein growing the first graphene layer over the first dielectric layer further comprises growing the first graphene layer on the source/drain contact, and the first graphene layer has a thinner thickness on the first dielectric layer than on the source/drain contact (claim 25);
wherein the first graphene layer comprises a first portion disposed between a sidewall of the first metal line and a sidewall of the first dielectric layer defining the first opening, and a second portion disposed between a bottom surface of the first metal line and the source/drain contact, wherein a thickness of the second portion is greater than a thickness of the first portion (claim 35).
However, Applicant has not disclosed that the ranges are for particular unobvious purpose, produce an unexpected result, or are otherwise critical. Therefore, It would have been obvious to one having ordinary skill in the art at the time the invention was made to include the above said teaching, since it has been held that where 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. In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955) (Claimed process which was performed at a temperature between 40°C and 80°C and an acid concentration between 25% and 70% was held to be prima facie obvious over a reference process which differed from the claims only in that the reference process was performed at a temperature of 100°C and an acid concentration of 10%.); see also Peterson, 315 F.3d at 1330, 65 USPQ2d at 1382 ("The normal desire of scientists or artisans to improve upon what is already generally known provides the motivation to determine where in a disclosed set of percentage ranges is the optimum combination of percentages."); In re Hoeschele, 406 F.2d 1403, 160 USPQ 809 (CCPA 1969) (Claimed elastomeric polyurethanes which fell within the broad scope of the references were held to be unpatentable thereover because, among other reasons, there was no evidence of the criticality of the claimed ranges of molecular weight or molar proportions.). For more recent cases applying this principle, see Merck & Co. Inc. v. Biocraft Laboratories Inc., 874 F.2d 804, 10 USPQ2d 1843 (Fed. Cir.), cert. denied, 493 U.S. 975 (1989); In re Kulling, 897 F.2d 1147, 14 USPQ2d 1056 (Fed. Cir. 1990); and In re Geisler, 116 F.3d 1465, 43 USPQ2d 1362 (Fed. Cir. 1997).
Claim(s) 22 and 30 is/are rejected under 35 U.S.C. 103 as being unpatentable over Yang/`279 in view of VARADARAJAN (Pub. No.: US 2022/0399230).
Yang/`279 teaches all the limitation of claim 11/21.
Yang/`279 fails to teach the limitation of claim 22/30.
VARADARAJAN teaches reacting an ammonia precursor with the carbon-containing gas to maintain a carbon-saturated environment (FIG. 4, [0098]) (claim 22).
wherein the carbon-containing gas comprises methane, ethane, propane, ethene, propene, acetylene, or combinations thereof (“hydrocarbon precursors that are alkanes (e.g., methane) “, [0039]) (claim 30).
It would have been obvious for a person of ordinary skill in the art before the effective filing date of the claim invention to include the above said teaching for the purpose of enhancing the growing in graphene in the semiconductor industry as taught by VARADARAJAN, [0002].
Moreover, after the combining of Yang and VARADARAJAN would teach reacting an ammonia precursor with the carbon-containing gas to maintain a carbon-saturated environment near the surface of the first dielectric layer.
Allowable Subject Matter
Claims 31 and 33-34 are allowed.
The following is an examiner’s statement of reasons for allowance:
In the claim 31 that is written, the prior arts fail to show or fairly suggest: “such that a second portion of the first graphene layer formed between the first metal line and the contact has a thicker thickness than a first portion of the first graphene layer formed between the sidewall of the first metal line and the first dielectric layer; depositing a second dielectric layer over the first metal line” in context with the other limitation as stated in claim 31.
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 TONY TRAN whose telephone number is (571)270-1749. The examiner can normally be reached Monday-Friday, 8AM-5PM, EST.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Britt Hanley can be reached at 571-270-3042. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/TONY TRAN/Primary Examiner, Art Unit 2893
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