DETAILED ACTION
This application, 18/222,086, attorney docket AD9667-US, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA . This application is assigned to Applied Materials, Inc., and claims priority from provisional application 63393089, filed 07/28/2022. Claims 1-12 were previously withdrawn by the applicant.
Response to Arguments
Applicant has amended claim 13 to clarify the extent of the etch, and correctly argues that the amendment overcomes the §112b rejection, which is withdrawn.
Applicant has amended claim 14 to clarify the composition gases of the etch plasm, and correctly argues that the amendment overcomes the §112b rejection, which is withdrawn.
Applicant has amended claims 15 and 16 to remove the limitation “independently” to clarify the extent of the etch, and correctly argues that the amendment overcomes the §112b rejection , which is withdrawn.
Applicant has amended the limitation “core layer” in claim 19 (erroneously cited by examiner as claim 20) to “pillar core layer, “and correctly argues that the amendment distinguishes the limitations and overcomes the §112d, which is withdrawn.
Applicant argues on page 10 of his response that the combination of Seo and Bea was improper because it relies on impermissible hindsight and because the statement that carbon-based selectivity to nitride or high-k oxides is conclusory to support the obviousness conclusion. Examiner disagrees.
In response to applicant's argument that the examiner's conclusion of obviousness is based upon improper hindsight reasoning, it must be recognized that any judgment on obviousness is in a sense necessarily a reconstruction based upon hindsight reasoning. But so long as it takes into account only knowledge which was within the level of ordinary skill at the time the claimed invention was made, and does not include knowledge gleaned only from the applicant's disclosure, such a reconstruction is proper. See In re McLaughlin, 443 F.2d 1392, 170 USPQ 209 (CCPA 1971). Here, the understanding in the art of selectivity of carbon to nitride and oxide is easily verified, see for example, Aquilino et al. U.S. 2013/0069160 paragraph [0022].
In response to applicant's argument that the examiner's statement was conclusory, the Federal Circuit has stated that "rejections on obviousness cannot be sustained with mere conclusory statements; instead, there must be some articulated reasoning with some rational underpinning to support the legal conclusion of obviousness." In re Kahn, 441 F.3d 977, 988, 78 USPQ2d 1329, 1336 (Fed. Cir. 2006); Here the examiner’s conclusion of obviousness was based on the articulated fact that carbon is known to be highly selective, so the statement is not conclusory.
Applicant argues that “claims must be construed in view of the specification and the particular problem solved by the invention. (See In re Omeprazole Patent Litigation, 536 F.3d 1361, 1380 (Fed. Cir. 2008) (There would have been no reason to modify the initial formulation because the prior art did not identify the problem, and even though the modification could have been made, the skilled artisan would have likely chosen a different modification upon recognition of the problem). Seo does not recognize that the etching of oxide mold stacks requires very thick layers, which makes high aspect ratio reactive ion etching harder.” Examiner disagrees. The Federal Circuit stated, “obviousness may be established by combining or modifying the teachings of the prior art to produce the claimed invention where there is some teaching, suggestion, or motivation to do so found either in the references themselves or in the knowledge generally available to one of ordinary skill in the art. See In re Fine, 837 F.2d 1071, 5 USPQ2d 1596 (Fed. Cir. 1988), In re Jones, 958 F.2d 347, 21 USPQ2d 1941 (Fed. Cir. 1992), and KSR International Co. v. Teleflex, Inc., 550 U.S. 398, 82 USPQ2d 1385 (2007). In this case, using a higher selectivity process is known in the art to widen process windows. (Again, see Aquilino [0022]).
Applicant argues that the art of record does not teach “performing a high aspect ratio etch to remove a portion of the first support layer and a portion of the second support layer between two adjacent pillars forming a high aspect ratio opening extending from the top surface of the hardmask layer to a top surface of the etch stop layer at the same time and in the same chamber as isotopically etching the mold stack to remove the first core carbon layer and the second core carbon layer,” However, this limitation is not recited in the amended claim. Instead, the claim recites, “and simultaneously performing a high aspect ratio etch of the mold stack to remove a portion of the first support layer and a portion of the second support layer between two adjacent pillars forming a high aspect ratio opening extending from the top surface of the hardmask layer to a top surface of the etch stop layer; and isotropically etching the mold stack to remove the first core carbon layer and the second core carbon layer.” In the claim, the punctuation of a semicolon indicates that the steps are separate, so examiner cannot conclude the steps are performed simultaneously.
If the claim was re-written to correct the §112 rejections and recite the limitation that the support layer is partially removed and the sacrificial core layer is removed in a single etch step, the claim would be distinguished from the art of record, and examiner will process assuming that the argued limitations would be used as filed claims.
An amended rejection is present below.
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.
Claims 13-20 are rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention.
Claim 13 recites, “forming a mold stack on an etch stop layer on a substrate, the mold stack comprising a first core carbon layer on an etch stop layer on a substrate,” “an etch stop layer” lacks proper antecedent.
Claim 13 recited, “and simultaneously performing a high aspect ratio etch of the mold stack to remove a portion of the first support layer and a portion of the second support layer between two adjacent pillars forming a high aspect ratio opening extending from the top surface of the hardmask layer to a top surface of the etch stop layer; and isotropically etching the mold stack to remove the first core carbon layer and the second core carbon layer. It is not clear what processes are being performed simultaneously. The language and syntax of the claim makes it impossible to determine what is being done simultaneously. Furthermore, the first support layer must be removed before the first core carbon layer, or the lower layers, in addition, it is not clear if one etch is both HAR and Isotropic , or if there are two chemistries at work.
Claims 14-20 depend from claim 13 and include the same defect.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
Claims 13, 16, 17 19 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Seo (U.S. 8,912,629) in view of Bae (U.S. 2009/0102017) and Kang (U.S. 2020/0219888) and Shreeram et al. (U.S. 2020/0243536) and Radosavljevic et al. (U.S. 2020/0373381).
As for claim 13,
Seo teaches in figures 1A-1K method of forming a semiconductor device, the method comprising:
forming a mold stack (100) on an etch stop layer (110) on a substrate (101/105), the mold stack comprising
a first core carbon layer (115) on an etch stop layer on a substrate,
a first support layer (120) on a top surface of the first core carbon layer,
a second core carbon layer (125) on the first support layer,
a second support layer (130) on the second core carbon layer,
a hardmask layer (135) on the second support layer, and a hardmask opening layer (145) on the hardmask layer;
etching a plurality of openings (140, holes shown in figure 1B) in the mold stack and in the etch stop layer (110), the plurality of openings extending from a top surface of the hardmask opening layer to a top surface of the substrate and having at least one sidewall and a bottom that is the top surface of the substrate (sidewall and exposed substrate shown in figure 1B);
conformally depositing an electrode layer (150, fig. 1C) in the plurality of openings on the at least one sidewall and on the bottom;
depositing a pillar core layer (160) on the electrode layer to at least partially fill the plurality of openings and form a plurality of pillars;
and simultaneously performing a high aspect ratio etch of the mold stack to remove a portion of the first support layer and a portion of the second support layer between two adjacent pillars forming a high aspect ratio opening extending from the top surface of the hardmask layer to a top surface of the etch stop layer; and
isotropically etching the mold stack to remove the first core carbon layer and the second core carbon layer.
performing a high aspect ratio etch Shown in figure 1g to remove a portion of the first support layer and a portion of the second support layer; (when?)
and exposing the mold stack to isotropic etching (shown in figure 1K)to remove the first core carbon layer and the second core carbon layer.
Seo does not teach that the first and second core layers are carbon.
However, Bae teaches that a carbon layer can be used as the sacrificial layer. Bae [0054,0056].
It would have been obvious to one skilled in the art at the effective filing date of this application to substitute the carbon mold layer for the dielectric of Bae because carbon-based materials can be removed by LAL etchant, and is highly selective to nitrides or high-k oxides Bae [0056]. One skilled in the art would have combined these elements with a reasonable expectation of success.
Seo does not teach simultaneously performing both a high aspect ratio etch of the mold stack to remove a portion of the first support layer and a portion of the second support layer between two adjacent pillars forming a high aspect ratio opening extending from the top surface of the hardmask layer to a top surface of the etch stop layer together with isotropically etching the mold stack to remove the first core carbon layer and the second core carbon layer.
However, Shreeram teaches in figure 3, simultaneously removing a portion of the support layers 212 and 206, the sacrificial layers 208 and 203 ([0029]).
It would have been obvious to one skilled in the art at the effective filing date of this application to substitute the removal step of Shreeram in to Seo to reduce the number of process steps required. One skilled in the art would have combined these elements with a reasonable expectation of success.
Seo does not teach that the high aspect etch remove portions of both the first and second support layers or that he isotropic etch removes both the first and second core carbon layers,
However, Kang teaches a high aspect etch to remove portions of both the first and second support layers and that he isotropic etch removes both the first and second core carbon layers.
It would have been obvious to one skilled in the art at the effective filing date of this application to use a single etch to remove the sacrificial layers and mold layer in one step to reduce manufacturing complexity. One skilled in the art would have combined these elements with a reasonable expectation of success.
Seo and does not teach that the first core carbon layer and the second core carbon layer comprising a plasma enhanced chemical vapor deposition (CVD) deposited carbon material.
However, Radosavljevic teaches in figure 1, forming a carbon layer (224) using PECVD [0033].
It would have been obvious to one skilled in the art at the effective filing date of this application to use PECVD to deposit a carbon material layer because There had been a finite number of identified, predictable potential solutions to deposit a carbon containing layer. One of ordinary skill in the art would have pursued the known potential solutions with a reasonable expectation of success, and selected PECVD to meet the design needs of the device . One skilled in the art would have combined these elements with a reasonable expectation of success.
As for claim 16,
Seo in view of Bae and Kang and Shreeram and Radosavljevic makes obvious the method of claim 13, and in the combination, Seo teaches that the first support layer comprises one or more of silicon carbonitride (SiCN), silicon nitride (SiN), and silicon oxide (SiO2),and second support layer independently comprises one or more of silicon carbonitride (SiCN), silicon nitride (SiN), and silicon oxide (SiO2). (SiN, Seo [co12 ln48]).
As for claim 17,
Seo in view of Bae and Kang and Shreeram and Radosavljevic makes obvious the method of claim 13, and in the combination, Seo teaches that the hardmask layer (135) comprises one or more of silicon oxide (SiOx), silicon carbide (SiC), carbon doped hydrogenated silicon oxide (SiOCH), boron (B), and boron nitride (BN). (Siox, Seo [co13 ln7]).
As for claim 19,
Seo in view of Bae and Kang and Shreeram and Radosavljevic makes obvious the method of claim 13, and in the combination, Seo teaches that the electrode layer comprises one or more of titanium (Ti), titanium nitride (TiN), tantalum (Ta), and tantalum nitride (TaN). " The lower electrode layer 150 may be formed of polysilicon, metal, or metal nitride. In some embodiments, the lower electrode layer 150 may be a titanium nitride (TiN) layer formed using a chemical vapor deposition process.” Seo [co13 ln35].
As for claim 20,
Seo in view of Bae and Kang and Shreeram and Radosavljevic makes obvious the method of claim 13, and Seo teaches that the pillar core layer comprises one or more of polysilicon, oxides, carbon doped oxides, silicon dioxide (SiO2), silicon nitride (SiN), silicon oxide/silicon nitride, carbides, oxycarbides, nitrides, oxynitrides, oxycarbonitrides, polymers, phosphosilicate glass, spin on dielectric (SOD) glass, organosilicate glass (SiOCH), and silicon carbo nitride (SiCN). (may be oxide or nitride Seo [co12 ln41].)
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Seo in view of Bae and Kang and Shreeram and Radosavljevic and in further view of Liu et al. (U.S. 2002/0173162).
As for claim 14,
Seo in view of Bae and Kang and Shreeram and Radosavljevic makes obvious the method of claim 13, but does not teach isotropic etching comprises exposure to radicals selected from one or more of oxygen (02), nitrogen (N2), hydrogen (H2), ammonia (NH3),
However, Liu teaches using oxygen in a capacitively coupled plasma etch chamber. Liu [0019]
It would have been obvious to one skilled in the art at the effective filing date of this application use an oxygen gas plasma to etch a dielectric because is have high selectivity for HAR etches through a resist. One skilled in the art would have combined these elements with a reasonable expectation of success.
Claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over Seo in view of Bae and Kang and Shreeram and Radosavljevic and in further view of Baraskar et al. (U.S. 2020/0388626).
As for claim 15,
Seo in view of Bae and Kang and Shreeram and Radosavljevic makes obvious the method of claim 13, but does not teach that the first core carbon layer and the second core carbon layer comprise a diamond-like carbon material.
However, Baraskar teaches using diamond like carbon as a sacrificial material.
It would have been obvious to one skilled in the art at the effective filing date of this application to use diamond-like carbon as a mold/sacrificial material because the material can be bulk removed with an ash. Baraskar [0361]. One skilled in the art would have combined these elements with a reasonable expectation of success.
Claim 18 is rejected under 35 U.S.C. 103 as being unpatentable over Seo in view of Bae and Kang and Shreeram and Radosavljevic and Baraskar and in further view of Naoki et al. (U.S. 2023/0151159).
As for claim 18,
Seo in view of Bae and Kang and Shreeram and Radosavljevic and Baraskar makes obvious the method of claim 17, but does not teach that the hardmask layer comprises boron (B) or boron nitride (BN).
However, Naoki teaches using a boron containing hardmask. Naoki, [0055].
It would have been obvious to one skilled in the art at the effective filing date of this application to substitute the boron containing hardmask into Seo because the boron improves etch resistance and adhesion. Naoki [0057]. One skilled in the art would have combined these elements with a reasonable expectation of success.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Wu (U.S.2023/0006032) teaches the simultaneous removal of support and sacrificial layers in figures 14 and 15.
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 JOHN A BODNAR whose telephone number is (571)272-4660. The examiner can normally be reached M-Th and every other Friday 7:30-5:30 Central time.
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/JOHN A BODNAR/ Primary Examiner, Art Unit 2893