DETAILED ACTION
This is the Office action based on the 18534061 application filed December 8, 2023, and in response to applicant’s argument/remark filed on February 2, 2026. Claims 1-20 are currently pending and have been considered below.
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 .
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 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.
Specification
The specification discloses a deposition of a gap-fill material into a plurality of openings by using a deposition agent, wherein in order to avoid pinch-off or void problem, an etching agent is added to remove material at the top of the opening ([0038-0041]). The specification further discloses that a higher RF power would increase the amount of such deposition relative to the etching, and teaches to switch between a periods of high power T1 and low power T2 ([0042-0043]) at a frequency 50 Hz -1 MHz, wherein T2 may be 5-95% of T2 ([0051-0052]). The specification further discloses that a high RF power may be 800-2000 W and the low RF power may be 100-500 W. It is noted that these are very broad ranges. The specification further discloses that the gap-fill material may be precursor for carbon, and the etching agent may be gases that etches carbon, such as carbon dioxide, hydrogen, ammonia, nitrous oxide, oxygen, etc. ([0044]), and teaches to perform experiments such as shown in Fig. 3 and 4 to determine the process condition to be used. It is noted that the flow rate shown in Fig. 3 and 4 refer to the combined flow rate of the deposition agent and the etching agent, without disclosing the flow rate of each gas individually. The specification does not disclose any range for a flow rate. The specification further discloses that the width of each opening may be 10-350 nm ([0032]), and the spacing between adjacent openings may be 10-350 nm ([0033]) or 90-450 nm ([0037]), and that the depth of each opening may be 1-35 um ([0034]). Again, it is noted that these are very broad ranges. Other than a general instruction that “(t)he methodology can involve an application of a time-dependent duty cycle during the deposition process. The time dependent duty cycle can include parameters that can be optimized based on the geometry of the patterned device. The parameters can include frequency of the duty cycle, multiple radio-frequency (RF) power values associated with a plasma deposition process, co-flow rates of an etchants and precursors for the plasma deposition process, types of etchants, types of precursors, and/or application times for the multiple RF power values. Application of the time-dependent duty cycle can promote sidewall growth for each trench or hole with deposition rates that depend on a CD associated with each trench or hole. The time dependent duty cycle can also discourage overgrowth pinch-off by etching overgrowth during a portion of the duty cycle without interrupting sidewall growth” ([0039]), the specification fails to disclose a best mode of practicing the invention, and does not disclose any specific example or embodiment that would enable the invention. According to MPEP 2164.06(a) section I, “Broad claim language is used at the peril of losing any claim that cannot be enabled across its full scope”. MPEP 2164.08 discloses the Federal Circuit has repeatedly held that “the specification must teach those skilled in the art how to make and use the full scope of the claimed invention without ‘undue experimentation’.” In re Wright, 999 F.2d 1557, 1561, 27 USPQ2d 1510, 1513 (Fed. Cir. 1993). Thus, for the purpose of examining it will be assumed that any process that meet the requirements shown above would read on the invention.
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.
The factual inquiries set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claims 1, 3-4, 6-18 and 20 rejected under 35 U.S.C. 103 as being obvious over Lin et al. (U.S. PGPub. No. 20240321581), hereinafter “Lin”, in view of Long et al. (U.S. PGPub. No. 20200335305), hereinafter “Long”.--Claim 1, 8, 16: Lin teaches a method of deposition a layer in a trench (Fig. 5A-C, [0028]) during manufacturing a NSFET comprising a fin (abstract, [0018-0020]), comprising(i) loading a substrate having a plurality of trenches, that is formed in a stack comprising alternate layers of silicon oxide and silicon nitride, into a process chamber (Fig. 3A and 17A, [0024, 0070]);(ii) etching a layer in the trench by supplying an etchant gas comprising HBr, Cl2, or combination thereof; and optionally O2, CO2, or combinations thereof ([0071]), while forming a passivation layer in the trench by supplying a passivation gas comprising CH4 and Ar, or SiCl4 , HBr and O2 into the chamber ([0073-0074]), then supplying a pulsed RF power source and a substrate bias power to generate a plasma ([0072]), wherein the SiCl4 , HBr and O2 may react and form SiBrO ([0074]). Therefore, it would have been obvious to one of ordinary skill in the art at the effective filing date of the invention, in routine experimentations, to use a gas comprising etching gas HBr and Cl2 together with passivation gas SiCl4 , HBr and O2 during the etching the layer in step (ii) above Lin is silent about the details of the pulsed RF power source. Long, also directed to etching a substrate during fabricating a semiconductor device by using a pulsed RF power source ([0001-0004]), teaches that the RF power source is advantageously pulsed in a multilevel fashion to improve etch rate, etch selectivity while prevent charging damage ([0007]), the multilevel pulsing comprises multiple power levels (Fig. 4C, 5A-B; [0056-0060]). Therefore, it would have been obvious to one of ordinary skill in the art at the effective filing date of the invention, to use the multi-level pulsing technique taught by Long, such as the pulse in Fig. 5B, to pulse the RF power source in the invention of Lin because Lin is silent about the details of the pulsed RF power source, and Long teaches that such multi-level pulsing would improve etch rate, etch selectivity while prevent charging damage. It is noted that during the first pulse in Fig. 5B, the gas flow includes the passivation gas SiCl4 , HBr and O2 , while applying a first RF power, and during the second pulse in Fig. 5B the gas flow includes the passivation gas SiCl4 , HBr and O2 , together with the etching gas HBr and Cl2 while applying a second RF power different from the first RF power. This reads on the claimed limitation “providing a precursor to a semiconductor processing chamber, wherein the precursor comprises a gapfill material for filling features in a semiconductor structure” and “providing an etchant to the semiconductor processing chamber together with the precursor in the processing chamber”. Although Lin is silent about a CD of the trenches, due to routine manufacturing fluctuation and variability, it would have been obvious to one of ordinary skill in the art at the effective filing date of the invention to form at least two trenches that do not have exactly the same CD in the invention of Lin. It is noted that the trenches would finish the etching process at the same time, and it would have been obvious that the passivation layer has an uniform thickness at the top of the trench. --Claim 3: Lin further teaches that the pulsed RF power may have a duty cycle of 20-100%. Although Lin and Long is silent about the duration of each power level, Fig. 4C shows that the first level is about 40% of the duty cycle, and the subsequent levels are about 30%, 20% and 10%, respectively. Therefore, the duration of each power level is a result-effective variable, and it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the invention to optimize the durations of the first power level, such as to greater than 50% of the duty cycle, because it’s been well established that "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955)”. MPEP 2144.05(II)(A).--Claim 4: It is noted that CH4 contain carbon.--Claims 6, 7: Lin teaches that the passivation layer is formed on the upper surface of the trench and on the sidewall of the trench during the etching ([0073]). Although Lin is silent about the RF power etches the top of the trench, since oxygen ions in the etching gas is capable of etching the hydrocarbon-containing passivation layer, it would have been obvious to one of ordinary skill in the art at the effective filing date of the invention, in routine experimentations, to etch at least a portion of the passivation layer on the upper surface of the trench.--Claims 9, 10, 11, 12, 13, 14, 15: Lin further discloses that a width of the trench is about 150 nm ([0082]). Therefore, it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the invention, in routine experimentations, to form the trench having a width less than 150 mm, or form a feature greater than 350 nm, or have a CD twice larger than another feature on the substrate in the invention of Lin.--Claims 17, 18: Fig. 17B shows no void at the top half of the trench while having voids 132P at the bottom of the trench.--Claim 20: Lin further discloses that the RF power may be 100-2500W. Although Lin and Long is silent about the power at power level, since the power level is a result-effective variable, and it would have been obvious to one of ordinary skill in the art prior to the effective filing date of the invention to optimize the first power level and other power levels because it’s been well established that "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955)”. MPEP 2144.05(II)(A).
Claim 2 rejected under 35 U.S.C. 103 as being obvious over Lin in view of Long as applied to claim 1 above, and further in view of Zhang et al. (U.S. PGPub. No. 20240194607), hereinafter “Zhang”.--Claim 2: Lin modified by Long teaches the invention as above. Lin is silent about the number of layers in the stack.Zhang, also directed to manufacturing a transistor comprising a fin made up of alternate layers of silicon oxide and silicon nitride, teaches that the number of the layers may be 128 (abstract, [0024]). Therefore, it would have been obvious to one of ordinary skill in the art at the effective filing date of the invention, to use a stack comprising 128 layers in the invention of Lin because Lin is silent about the details of the number of layers, and Zhang teaches that such number of layers would be effective.
Claims 5 and 19 rejected under 35 U.S.C. 103 as being obvious over Lin in view of Long as applied to claim 1 above, and further in view of Kanarik et al. (U.S. PGPub. No. 20130119019), hereinafter “Kanarik”.--Claim 5: Lin modified by Long teaches the invention as above. Lin fails to teach that a flow rate of a co-flow is greater during a second period than during the first period.Kanarik, also directed to plasma etching while pulsing a RF power source, teaches that an inert gas flow should be pulsed along with the RF power source pulse, wherein they have the same or a different duty cycle ([0027]) to improve etch uniformity, directionality and selectivity ([0044]). Therefore, it would have been obvious to one of ordinary skill in the art at the effective filing date of the invention, to also pulse the Ar gas flow in tandem with the RF power pulse in the invention of Lin because Kanarik teaches that this would improve etch uniformity, directionality and selectivity.--Claim 19: It is noted that the duty cycle comprises a square wave.
Response to Arguments
Applicant's arguments filed February 2, 2026 have been fully considered as follows:--Regarding Applicant’s argument that, although a best mode or a specific example for using the invention is not provides, the specification discloses a clear roadmap for optimizing a process of filling a features in a semiconductor structure, this argument does not properly address the issue that the operating ranges taught by the invention are very broad. According to MPEP 2164.06(a) section I, “Broad claim language is used at the peril of losing any claim that cannot be enabled across its full scope”. MPEP 2164.08 discloses the Federal Circuit has repeatedly held that “the specification must teach those skilled in the art how to make and use the full scope of the claimed invention without ‘undue experimentation’.” In re Wright, 999 F.2d 1557, 1561, 27 USPQ2d 1510, 1513 (Fed. Cir. 1993). For example, the specification discloses that the gap-fill material may be precursor for carbon, and the etching agent may be gases that etches carbon, such as carbon dioxide, hydrogen, ammonia, nitrous oxide, oxygen, etc. ([0044]), and teaches to perform experiments such as shown in Fig. 3 and 4 to determine the process condition to be used. However, the specification does not disclose any range for any flow rate, and the flow rates shown in Fig. 3 and 4 refer to the combined flow rate of the deposition agent and the etching agent without disclosing the flow rate of each gas individually. For the purpose of examining it will be assumed that any process that meet the operating ranges would read on the invention.--Regarding Applicant’s argument that the cited prior arts do not teach the claimed feature “providing an etchant to the semiconductor processing chamber together with the precursor in the processing chamber”, Lin clearly discloses this feature, as explained above.
Conclusion
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 mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to THOMAS PHAM whose telephone number is (571) 270-7670 and fax number is (571) 270-8670. The examiner can normally be reached on MTWThF9to6 PST.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Joshua Allen can be reached on (571) 270-3176. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/THOMAS T PHAM/Primary Examiner, Art Unit 1713
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