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 .
Election/Restrictions
Claims 11-19 withdrawn from further consideration pursuant to 37 CFR 1.142(b), as being drawn to a nonelected invention, there being no allowable generic or linking claim. Applicant timely traversed the restriction (election) requirement in the reply filed on June 25, 2026.
Applicant's election with traverse of Group 1 in the reply filed on June 25, 2026 is acknowledged. The traversal is on the ground(s) that a search for Groups I or II would yield references applicable to Groups I and II, as such the is no serious search burden. This is not found persuasive because the search for the apparatus encompasses art areas outside the search need for the method.
The requirement is still deemed proper and is therefore made FINAL.
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 1-4, 6, 8, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Na et al. (US 2024/0047269 A2) in view of KR 10-2016-0116171 (hereafter KR ‘171).
Na et al. method for forming a metal silicide layer on a substrate (¶0081), the method comprising:
positioning a substrate within a processing chamber (substrate provided to semiconductor process tool ¶0071; Figs 8, 9A, and 9B), the substrate comprising a feature formed within a dielectric layer formed over an underlayer of the substrate (trenches/vias formed in dielectric material ¶¶0072-0074, Fig. 3A and 3B);
delivering RF power to the processing chamber to generate a plasma over the substrate (¶0140), wherein generating the plasma comprises:
delivering a processing gas during a first time period (process gases, carrier gases, inert gases, and recipe phases ¶¶0134, 0142);
delivering a reactive gas into a flow of the processing gas during a second time period to form a pretreatment gas (blending a Mo precursor-containing gas, hydrogen-containing gas, and carrier gas in a mixing vessel ¶0134);
delivering a deposition gas during a third time period, the deposition gas comprising a precursor gas and the pretreatment gas (Mo precursor and reducing agent for Mo deposition ¶¶0078–0082, 0093–0095); and
delivering a post-treatment gas during a fourth time period (recipe phases involving modulation of reactant, carrier, purge, and plasma gases ¶0142);
halting the delivering of the RF power and delivering the precursor gas into a flow of the post-treatment gas (RF power control generally ¶¶0140, 0151, 0159); and
purging the processing chamber during a sixth time period (carrier and purge gases and recipe phases involving purge-gas flow ¶0142).
However, Na et al. does not clearly disclose adding the reactive gas during a distinct second period to form a pretreatment gas. Na et al. discloses that gas flows may be modulated or stopped during recipe phases, but the supplied portions do not clearly disclose stopping the Mo precursor specifically during a post-treatment period. Na et al. does not clearly disclose stopping RF power at the claimed point in the sequence.
To the extent Na et al. does not expressly disclose terminating RF power while continuing precursor delivery during a subsequent plasma-off period, that difference would have been an obvious process-sequencing modification in view of KR ’171.
KR ’171 teaches that precursor delivery, reactive-gas delivery, plasma power, and purge gas may be independently controlled during separate, timed process periods. The artisan would therefore have recognized that the precursor exposure and plasma exposure need not be simultaneous and would have selected a plasma-off precursor exposure as a routine process variation to control precursor adsorption, surface reaction, or film growth. The claimed fifth-period operation is therefore not new, but an alternative timing arrangement using the same precursor, reactive gas, chamber, and process-control components already taught by Na et al. and KR ’171.
It would have been obvious to a person of ordinary skill in the art to modify the method of Na et al. by applying the time-divided process sequencing of KR ’171. Na et al. teaches processing a substrate having a dielectric feature over an underlying metal-silicide or semiconductor surface in an RF-plasma-capable processing chamber, using a molybdenum-containing precursor, a reducing gas, carrier gas, and purge gas. KR ’171 teaches independently controlling precursor-gas delivery, reactive or plasma-source-gas delivery, plasma power, and purge-gas delivery during separate, predetermined time periods.
The skilled artisan would have been motivated to combine these teachings to provide independent control of surface pretreatment, Mo-precursor deposition, post-deposition treatment, precursor exposure, and chamber purging. In the resulting process, the reactive gas would be introduced before the Mo precursor to condition the exposed surface, the Mo precursor would then be introduced for plasma-assisted deposition, precursor flow would be stopped for post-treatment, RF power would be terminated while precursor exposure continued in the post-treatment gas, and the chamber would thereafter be purged. This modification would have been a predictable use of known gas-flow and plasma-power controls for their intended purposes, with a reasonable expectation of controlling surface reaction, reducing residual precursor and byproducts, and improving deposition repeatability and selectivity. Accordingly, claim 1 would have been obvious over Na et al. in view of KR ’171.
Regarding claim 2, Na et al. in view of KR ’171 teaches the method of claim 1, wherein the precursor gas comprises a molybdenum (Mo) containing precursor gas (Na et al. ¶0134).
Regarding claim 3, Na et al. in view of KR ’171 teaches the method of claim 2, wherein the Mo containing precursor gas comprises molybdenum pentachloride (MoCls) (Na et al. ¶¶0015-0017, 0043).
Regarding claim 4, Na et al. in view of KR ‘171 teaches the method of claim 1, wherein
Na et al. discloses the reactive gas is delivered at a first reactive gas flow rate during the second time period and the third time period (hydrogen-containing or reducing gas and recipe-phase gas-flow control ¶¶0134, 0142)
Na et al. does not clearly identify the same first flow rate during both period.
Na et al. discloses a second reactive gas flow rate during the fourth time period (discloses modulation of reactant, carrier, and purge-gas flows during recipe phases ¶0142), at a third reactive gas flow rate during the fifth time period, and a fourth reactive gas flow rate during the sixth time period (Na et al. teaches recipe-based modulation of precursor, reactant, carrier, and purge-gas flow during different process phases.)
KR ’171 further teaches supplying process gases at preset flow rates for respective preset time periods while independently controlling plasma power and purge-gas delivery.
It would have been obvious to use the independent flow control of KR ’171 in Na et al.’s Mo deposition process and to assign different reactive-gas flow rates to the pretreatment, deposition, post-treatment, plasma-off exposure, and purge periods. Such adjustment would have been a routine process optimization for controlling plasma chemistry, surface conditioning, deposition rate, and removal of residual gases.
Regarding claim 6, Na et al. in view of KR ‘171 teaches the method of claim 4, wherein the processing gas is provided at a processing gas flow rate but does not explicitly details about a first, second, third, fourth, fifth, and sixth time periods.
Na et al. teaches supplying process, carrier, inert, and purge gases during recipe phases and controlling the flows of those gases using a system controller. (¶¶0134 and 0142).
KR ’171 teaches time-divided delivery of precursor, plasma-source, and purge gases during predetermined process periods.
It would have been obvious to maintain the processing or carrier gas of Na et al. during each phase of the time-divided process of KR ’171 to provide carrier-gas continuity, stabilize the processing environment, facilitate delivery of the precursor and reactive gas, and assist with removal of residual gases during the purge phase. Therefore, claim 6 would have been obvious over Na et al. in view of KR ’171.
Regarding claim 8, . Na et al. in view of KR ‘171 teaches the method of claim 6, but does not detail a ratio between the second reactive gas flow rate and the processing gas flow rate is between 0:1 and 5:1.
Na et al. teaches a plasma-assisted Mo deposition process in which a substrate having a dielectric feature is exposed to a Mo-containing precursor, a reducing or reactive gas, carrier gas, and purge gas. Na et al. further teaches controlling and modulating delivery of the precursor, reactant, carrier, and purge gases during different recipe phases (¶¶0134, 0140, and 0142).
KR ’171 teaches a time-divided plasma process in which precursor gas, plasma-source or reactive gas, plasma power, and purge gas are independently supplied during respective predetermined periods and at controlled flow rates.
It would have been obvious to apply this time-divided gas-flow control to Na et al.’s Mo deposition process, including reducing or stopping reactive-gas flow during the fourth, post-treatment period while maintaining the processing or carrier gas. Such a process would provide a second reactive-gas flow rate that may be zero or a nonzero value selected up to the processing-gas flow rate ratio of 5:1. For example, where the reactive gas is stopped during the fourth period, the ratio is 0/Rprocessing gas = 0, which falls within the claimed range of 0:1 to 5:1. Alternatively, a reduced reactive-gas flow relative to the processing gas would yield a ratio within the claimed range. The selection would have been a predictable process-control modification for controlling post-treatment chemistry, limiting unwanted reactions, stabilizing the chamber, and facilitating transition to the subsequent precursor and purge operations. Accordingly, claim 8 would have been obvious over Na et al. in view of KR ’171.
Regarding claim 20, Na et al. discloses a method for forming a metal silicide layer on a substrate, the method comprising:
positioning a substrate within a processing chamber (substrate to a semiconductor processing tool ¶¶0071, Figs. 8, 9A and 9B), the substrate comprising a feature formed within a dielectric layer formed over an underlayer on the substrate (trenches/vias formed in dielectric material ¶¶0072-0074, Fig. 3A and 3B);
delivering an RF power to the processing chamber to generate a plasma over the substrate (¶0140), wherein generating the plasma comprises:
delivering a processing gas during a first time period (process gases, carrier gases, inert gases, and recipe phases ¶¶0134, 0142);
delivering hydrogen (H2) into a flow of the processing gas (hydrogen-containing gas and mixing/conditioning of process gases in a mixing vessel ¶0134) during a second time period to form a pretreatment gas;
delivering a deposition gas during a third time period, the deposition gas comprising a molybdenum (Mo) containing precursor gas and the pretreatment gas (Mo precursor and reducing-agent delivery ¶¶0078–0082, 0093–0095); and
delivering a post-treatment gas during a fourth time period, wherein delivering the post-treatment gas comprises halting the delivering of the Mo containing precursor gas during the fourth time period to form the post-treatment gas (modulating or stopping reactant/precursor and carrier/purge gas flows in recipe phases ¶0142); and
halting the delivering of the RF power and delivering the Mo containing precursor gas into a flow of the post-treatment gas during a fifth time period (RF-power control and controller-based process sequencing ¶¶0140, 0151–0159); and
purging the processing chamber during a sixth time period (carrier and purge gases and purge-gas recipe instructions ¶¶0134, 0142).
KR ’171 teaches time-dividing a plasma-assisted deposition process into separate periods in which precursor gas, plasma-source or reactive gas, plasma power, and purge gas are independently supplied or controlled. (¶¶0027–0028, 0037 and Figures 1–2). KR ’171 also teaches independently timing precursor-gas delivery and plasma-power application. A skilled artisan would have recognized that the Mo precursor could be delivered during a plasma-off interval after the plasma-assisted deposition and post-treatment stages. Such a plasma-off precursor exposure would have been a predictable alternative for increasing precursor adsorption or allowing a surface-mediated reaction without continued plasma exposure. The change would merely alter the timing of known process inputs while retaining the same gases, chamber, and controller.
It would have been obvious to modify Na et al.’s Mo deposition process according to the time-divided gas and plasma control of KR ’171. The resulting process would include supplying a carrier or processing gas, adding hydrogen during a pretreatment period, supplying the Mo precursor with the hydrogen-containing gas during deposition, stopping precursor delivery during a post-treatment period, terminating RF power while continuing precursor delivery in the post-treatment-gas flow, and subsequently purging the chamber.
A skilled artisan would have been motivated to use this sequence to independently control surface pretreatment, precursor adsorption, plasma-assisted Mo deposition, post-treatment chemistry, plasma exposure, and removal of residual precursor and reaction products. The modification would have involved using known gas-flow and plasma-power controls in a conventional time-divided recipe, with a reasonable expectation of success. Accordingly, claim 20 would have been obvious over Na et al. in view of KR ’171.
Claims 5, 7, 9, and 10 are rejected under 35 U.S.C. 103 as being unpatentable over Na et al. in view of KR ‘171 as applied to claim 1, 4, and 6 above, further in view of Tsunatori et al. (US 2024/0274433 A1).
Regarding claim 5, Na et al. in view of KR ‘171 the method of claim 4, wherein the precursor gas is delivered at a first precursor gas flow rate during the third time period (Na et al. Mo precursor for deposition flow control and recipe instructions ¶¶0078–0082, 0093–0095, 0134, 0142).
Na et al. in view of KR ‘171 does not explicitly teach the ratio between the first reactive gas flow rate and the first precursor gas flow rate is between 1:50 and 100000:1.
Na et al. discloses a plasma-assisted process for depositing molybdenum in a feature formed in a dielectric layer, using a molybdenum-containing precursor, a reducing gas such as hydrogen, and carrier or purge gases. Na et al. further discloses controlling process-gas and reactant-gas delivery through recipe phases.
KR ’171 teaches time-divided semiconductor processing in which precursor gas, plasma-source gas, plasma power, and purge gas are supplied at selected flow rates during respective process periods. Accordingly, KR ’171 would have suggested implementing Na et al.’s Mo deposition process using independently controlled precursor and reactive-gas flow rates during the deposition period.
Tsunatori et al. further demonstrates that, in cyclic plasma deposition, the relative flow rates of a precursor gas and a reactive gas are routinely selected and adjusted to control deposition behavior, coverage, and growth-per-cycle. Tsunatori et al. discloses, for example, a precursor flow of 100–1,000 sccm and a nitrogen-containing reactive-gas flow of 100–1,000 sccm, which yields reactive-gas-to-precursor ratios within the range recited in claim 5.
It would therefore have been obvious to select a reactive-gas-to-precursor flow-rate ratio within the claimed range when applying the time-divided process of KR ’171 to the Mo deposition process of Na et al. Such selection would have involved routine optimization of a result-effective variable, with a reasonable expectation of controlling precursor concentration, plasma chemistry, deposition rate, and film properties.
Regarding claim 7, Na et al. in view of KR ‘171 discloses the method of claim 6, but does not teach details about the ratio between the first reactive gas flow rate and the processing gas flow rate is between 1:200 and 5:1.
Na et al. teaches a plasma-assisted process for processing a substrate having a feature formed in a dielectric layer over an underlayer. Na et al. further teaches delivering a molybdenum-containing precursor, a reactive or reducing gas, and a carrier or processing gas in recipe-controlled process phases (¶¶0071–0082, 0134, 0140, and 0142).
KR ’171 teaches time-divided semiconductor processing in which precursor gas, plasma-source or reactive gas, plasma power, and purge gas are delivered during respective predetermined process periods and at controlled flow rates. KR ’171 would have suggested implementing the process of Na et al. using independently controlled gas-flow rates during the claimed pretreatment and deposition periods.
Tsunatori et al. further teaches selecting and varying the relative flow rates of a precursor-related gas, a reactive nitrogen-containing gas, and an inert Ar gas during different plasma-enhanced deposition operations. In particular, Tsunatori et al. discloses nitrogen-containing-gas flow rates of 10–1,000 sccm and Ar flow rates of 50–2,000 sccm. These disclosed flow rates include combinations having reactive-gas-to-processing-gas ratios within the range of 1:200 to 5:1 recited in claim 7. For example, a reactive-gas flow rate of 10 sccm and an Ar flow rate of 2,000 sccm provides a ratio of 1:200, while a reactive-gas flow rate of 1,000 sccm and an Ar flow rate of 200 sccm provides a ratio of 5:1.
It would have been obvious to select a reactive-gas-to-processing-gas flow-rate ratio within the claimed range when applying the time-divided process control of KR ’171 to the plasma-assisted Mo deposition process of Na et al. The relative flow rate of reactive gas to carrier or processing gas would have been recognized as a result-effective variable affecting plasma chemistry, reactive-species concentration, precursor transport, deposition rate, surface pretreatment, and selectivity. Selecting a ratio within the disclosed and overlapping range would have involved routine optimization of known process parameters, with a reasonable expectation of success. Accordingly, claim 7 would have been obvious over Na et al. in view of KR ’171 and Tsunatori et al..
Regarding claim 9, Na et al. in view of KR ‘171 discloses the method of claim 6, but does not teach details wherein a ratio between the third reactive gas flow rate and the processing gas flow rate is between 1:200 and 5:1.
Na et al. teaches controlling delivery of reactive, carrier, inert, and precursor gases during recipe phases of a plasma-assisted Mo deposition process. KR ’171 teaches dividing a plasma process into successive time periods and independently controlling precursor-gas delivery, reactive/plasma-source-gas delivery, and plasma power during those periods. It would have been obvious to use a separately controlled reactive-gas flow during the fifth period, in which RF power is stopped and precursor gas is supplied in the flow of the post-treatment gas.
Tsunatori et al. further teaches selecting and varying reactive-gas and carrier-gas flow rates during different plasma-enhanced deposition operations. D6 discloses reactive-gas flow rates of approximately 10–1,000 sccm and Ar flow rates of approximately 50–2,000 sccm. These disclosed values include ratios within the claimed 1:200 to 5:1 range. For example: 10 sccm / 2000 sccm = 1:200 and 1000 sccm / 200 sccm = 5:1.
It would have been obvious to select a third reactive-gas flow rate relative to the processing-gas flow rate within the claimed range during the fifth period. The ratio would have been a result-effective variable affecting precursor transport, surface conditioning, reactive-species concentration, plasma chemistry, and deposition behavior. The selection would have involved routine optimization of known process parameters with a reasonable expectation of success. Accordingly, claim 9 would have been obvious over Na et al. in view of KR ’171 and Tsunatori et al.
Regarding claim 10, Na et al. in view of KR ‘171 discloses the method of claim 6, but does not teach details wherein a ratio between the fourth reactive gas flow rate and the processing gas flow rate is between 1:200 and 5:1.
Na et al. teaches supplying carrier and purge gases during recipe phases and controlling process-gas and reactant-gas flow using a process controller. KR ’171 teaches a separately controlled purge period in which purge gas is delivered to the processing chamber for a selected time and flow condition. It would have been obvious to apply this purge-phase control to the sixth period of the Na et al. process.
Tsunatori et al. further teaches changing gas-flow conditions during purge and other post-deposition operations and discloses reactive-gas and Ar flow rates that provide ratios between 1:200 and 5:1. For example, 10 sccm of reactive gas and 2000 sccm of Ar yields 1:200, while 1000 sccm of reactive gas and 200 sccm of Ar yields 5:1.
A person of ordinary skill in the art would have selected a fourth reactive-gas flow rate relative to the processing-gas flow rate within the claimed range to improve purge efficiency, remove residual precursor and reaction byproducts, stabilize the chamber, and condition the substrate surface before the next deposition cycle. The claimed ratio would have been a result-effective process variable, and its selection would have involved routine optimization with a reasonable expectation of success. Accordingly, claim 10 would have been obvious over Na et al. in view of KR’ 171 and Tsunatori et al.
Conclusion
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/SUE A PURVIS/ Supervisory Patent Examiner, Art Unit 2893
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