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
Applicant’s election without traverse of Group I, claim s1-18 in the reply filed on 02/13/2026 is acknowledged.
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.
The factual inquiries 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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim(s) 1-18 is/are rejected under 35 U.S.C. 103 as being unpatentable over Nishimura et al. (US 2017/0222139) in view of Murakami (US 20210098267), and Zhai et al. (US 20180345330).
As to claims 1, 16, Nishimura et al. discloses a plasma processing method comprising; providing a substrate including a first region made of a first material (metal layer – L4 of Fig. 4; 0074); and a second region formed of a second material different from the first material (mask- MSK of Fig. 4, 0075);
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supplying a modifying gas for modifying the surface of the first region (see 0079 – the first process gas radicals that causes a reduction, oxidation, chlorination, or fluorination reaction); supplying a second processing gas that reacts with the substance to be etched (see 0080 – the second processing gas can be HF, CL2, HCl, H2O, F2, ClF3, COF2, cyclopentadiene, or Amidinato (see 0080); the second processing gas reacts with the radicals formed from the first gas to remove the deposits formed by radicals (see 0081). Nishimura et al. states the first processing gas is supplied with plasma and the second gas is supplied when the plasma source is stopped so the etching occurs without plasma (see 0081).
As to claim 17, the support structure contains an electrode (see 0150).Nishumra et al. further teaches where the modification occurs with plasma (RF applied) and a second period where no plasma is supplied (during etching step) (0081). Nishimura et al. further teaches these steps can be alternated (see 0152).
Nishimura et al. fails to teach forming a modified layer by modifying the surface of the first region with plasma generated from a gas mixture including the modifying gas and the carbon-containing precursor as required by claims 1 and 16, or supplying a gas including at least one halogen or oxygen and carbon-containing precursor as required by claim 17.
Nishimura et al. discloses instances where the second processing gas can comprise a carbon containing material (see 0080, COF2, cyclopentadiene and Amidinato). Nishimura et al. teaches instances where the second processing gas can be a carbon-containing material but does not explicitly state the second material is carbon-containing as required by the claims.
Murakami teaches that carbon-containing gases may be supplied during metal etching processes to react with the surface of the metal, where carbon atoms absorb onto the surface and modify the surface chemistry of the metal layer (see 0051). Murakami further explains that such carbon-containing gases can prevent excessive oxidation and allow for more uniform etching of the metal surface (see 0051).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the process of Nishimura et al. to include a carbon-containing material as the second processing gas as taught by Murakami. One would have been motivated to do so since both teach processes for etching layers where Murakami teaches the use of a carbon-containing material after a reduction step to react with the layer to allow uniform etching of the surface especially since Nishumra et al. does teach the gas can be a carbon containing materials.
Zhai et al. discloses a plasma cleaning and etching process using a gas mixture including both halogen-containing gasses and carbon-containing gases. Zhai et al. teaches introduction a mixture comprising a halogen- containing gas and carbon-containing gas into a chamber (see 0054). Zhai et al. further teaches the gas is exposed to an RF source to energize the gas mixture (see 0056), and that bias power may be applied to enhance etching reactions at the substrate surface. Zhai et al. further teaches a bias can be applied to establish an electrical potential difference between plasma and the substate to enhance etching (see 0057). The plasma is performed using RF power of 0.3 – 14 MHz (see 0056), the bias is applied at 300kHz (see 0057).
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to modify the process of Nishimura et al. to include providing the carbon -containing gas during the plasma step as taught by Zhai et al. in order to control plasma chemistry and reactive species generation. Plasma processing systems commonly utilize gas mixtures to tailor plasma chemistry, and introducing additional gases into the plasma is a routine technique for adjusting the concentration of reactive radicals and controlling surface reactions occurring at the substrate.
As to claim 2, the first region includes a metal-containing film, and the second includes a mask (see Nishimura et al. , Fig. 4 above).
As to claim 3, the carbon-containing material does not contain a metal (see 0080, COF2, cyclopentadiene and Amidinato of Nishimura et al.; 0054 of Zhai et al.).
As to claim 4, Murakami teaches the carbon containing gas can be an alcohol gas (see 0052).
As to claim 5, Zhai teaches supplying the gas mixture including carbon-containing and halogen-containing gas to the processing chamber where the mixture is energized (See 0054-56). Supplying a gas mixture during plasma processing would involve continuous gas flow.
As to claim 6, Zhai teaches repeating the modifying and removal step until the desired cleaned endpoint is achieved (see 0069).
As to claim 7, Nishimura et al. fails to explicitly teach the substrate is heated as required by the claim. Nishimura et al. states the etching (removing) step is dependent upon the temperature of the placing table (see 0010, 0080). The temperature/heating is therefore a result effective variable. Nishimura et al. further states a heater for heating the substrate is provided in the electrostatic chuck holding the wafer. It would have been obvious to one having ordinary skill in the art before the effective filing date to heat the substrate through routine experimentation in order to control the etching/ removal of the layer especially since Nishimura et al. teaches a heater within the system that can be used to heat the substrate.
As to claims 8-10, Nishimura et al. modified by Murakami and Zhai as discussed above, teaches the modifying gas can be a chlorine or fluorine-containing gas (see 0079 of Nishimura et al.; 0054 of Zhai et al.). The gas can be NF3, Cl2, SF6, (see 0054 of Zhai et al.; 0079 of Nishimura et al.).
As to claim 11, Nishimura et al. teaches stopping the supply of radio frequency power so that plasma is not generated (see 0081).
As to claim 12, Nishimura et al. teaches the deposit can be formed on the mask (See 0165).
As to claim 13, Zhai et al. teaches a bias power is applied to establish electrical potential difference between the plasma and the substrate to enhance etching (see 0057) where the bias is supplied to an electrode in the substrate support (see 0041).
As to claim 14, Nishimura et al. modified by Murakami and Zhai et al. does not state the first bias power time is shorter than the radio frequency supplied as required by claim 14. The amount of time providing RF controls the reactive species formed and the amount of time of the bias controls how well the plasma is sustained, therefore, these are result effective variables. It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to use the claimed relative time differences through routine experimentation in order to optimize surface modification.
As to claim 15, Nishimura et al. modified by Murakami and Zhai et al. fail to teach a first bias power and a second bias power larger than the first bias as required by the claim. Zhai et al. teaches applying bias power during plasma processing (see 0056) in order to sustain the plasma (see 0056). Zhai et al. further teaches pulsing of the bias. It would have been obvious to one having ordinary skill in the art to modify the process of Nishimura et al. modified by Murakami and Zhai et al. to include varying the bias through routine experimentation in order to sustain the plasma within the system to perform the modification step.
As to claim 18, Nishimura et al. teaches the frequency can be modulated to attract ions to the wafer (see 0064-0065). The power supply can supply the same or different frequencies (see 0088). The frequency is adequate to excite the processing gas and form the radicals (see 0088). Zhai et al. teaches a bias can be applied to establish an electrical potential difference between plasma and the substate to enhance etching (see 0057). The plasma is performed using RF power of 0.3 – 14 MHz (see 0056), the bias is applied at 300kHz (see 0057).
It would have been obvious to one having ordinary skill in the art before the effective filing date to modify the radio frequency as claimed through routine experimentation in order to optimize the formation of the desired radicals on the surface of the region, especially since Nishimura et al. teaches modulation of the frequency and to successfully etch the surface as an alternative method for etching.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Anthis et al. (US 2018/0342403) discloses a process for selectively dry etching a metal film (see abstract), The process comprises exposing the substrate to a halogenating material (see 0031-0032) which can occur thermally or with a plasma (see 0033); after halogenation , the substrate is exposed to a ligand transfer agent to remove the halogenating material (see 0036). Anthis et al. states atomic layer etching can occur in a time-domain or special process. In the time domain process the gasses are separated by a time delay/pause to allow the gasses to treat to the substrate surface (the gases are provided sequentially – see 0039). Spatial ALE is when two different gasses are provided in two different regions of the processing chamber, exposure to the gases can occur simultaneously to different parts of the substrate (see 0040).
Zaitsu (US 9735024) teaches a process for etching a layer on a substrate comprising providing a substrate; exposing the substrate to a pulse of etchant gas (fluorocarbon gas containing a function group with polarity) to chemisorb the etchant gas on the surface; and providing a pulse of a reactive species of a noble gas to etch the layer (see claim 1).
Papalia et al. (US 2020/0321220) teaches a process for etching a metal based film having a mask thereon (See abstract, Fig. 1, 0029-0032). The process comprises providing a background plasma (noble gas; see 0044); introducing a modifying gas to form a modifying plasma where the modifying gas includes a halogen gas (see 0047) and forming a modified portion on the metal film (See 0048); a bias power is applied to the substate which helps with etching the modified portion (see 0050). Papalia et al. further teaches during the bias step additional gas chemistries can be provided which interact with the chemistry of the surface modification reaction (see 0050); the bis is removed and the modified portion is etched (see 0051, Figs. 5-8).
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/CACHET I. PROCTOR/
Examiner
Art Unit 1712
/CACHET I PROCTOR/ Primary Examiner, Art Unit 1712