DETAILED ACTION
Claims 1-20 are pending before the Office for review.
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
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.
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.
Claims 1-12 and 14-18 are rejected under 35 U.S.C. 103 as being unpatentable over LI et al (U.S. Patent Application Publication 2019/0326123).
With regards to claims 1-10, Li discloses a method comprising flowing a precursor comprising on or more an halogen containing species wherein the halogen contain species comprises one or more fluorine (F2) or xenon difluoride, into a semiconductor processing chamber containing a substrate; exposing the substrate to the precursor and etching the substrate, the substrate having a plurality of alternating layer of silicon and silicon oxide thereon, wherein the silicon layers are selectively etched relative to the silicon oxide layers (Paragraphs [0042]-[0045]).
Li does not explicitly discloses forming an activated species of the precursor.
However Li discloses wherein during etching a plasma may be generated (Paragraphs [0027], [0036]) or plasma free operation wherein the precursors are in a state where they posses energetically favorable etch reaction pathway wherein the process conditions are performed at a higher temperature to provide higher etch rates (Paragraphs [0041]-[0048]) which renders obvious forming an activated species of the precursor; exposing the substrate to the activated species; and etching the substrate.
It would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the invention to modify the embodiment of Li to include the activation as rendered obvious by Li because the reference of Li teaches activating the precursors provide precursors in a state wherein higher etch rates are provided (Paragraph [0048]) and one of ordinary skill in the art prior to the effective filing date of the invention would have had a reasonable expectation of predictably achieving the desired etching using the activated species as rendered obvious by the teachings of Li MPEP 2143D
The Examiner would like to note that while Li does disclose an interhalogen, sulfur-containing species, pseudohalogen, amine, phosphine, glycol or acid, such precursors are not required by the currently presented claim. The currently presented claims recites “… flowing a precursor comprising one or more of an interhalogen, a halogen-containing species, a pseudohalogen species, a mixture of one or more of the interhalogen, the halogen-containing species, or the pseudohalogen species and one or more of an amine, a phosphine, a glycol, or an acid, or a mixture of one or more of the interhalogen, the halogen-containing species, or the pseudohalogen species and a sulfur-containing species” and therefore the Examiner’s position that a rejection under the disclosure of a halogen containing species address the claims as currently presented.
With regards to claim 11, the modified teachings of Li renders obvious wherein forming the activated species comprises one or more of a thermal process or generating a plasma of the precursor (Paragraphs [0036], [0048])
With regards to claim 12, the modified teachings of Li renders obvious wherein the plasma is generated by one or more of a remote plasma source or a capacitively coupled plasma (CCP) source. (Paragraphs [0030], [0035]-[0037]).
With regards to claim 14, the modified teachings of Li renders obvious wherein the silicon layers are etched relative to the silicon oxide layers at a selectivity ratio of greater than or equal to 50:1. (Paragraph [0058]).
With regards to claim 15, the modified teachings of Li renders obvious wherein the substrate comprises a trench having a depth of a few microns (Paragraph [0046]) which renders obvious greater than or equal to 1 µm. In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976). MPEP 2144.05(I)
With regards to claim 16, the modified teachings of Li renders obvious wherein the semiconductor processing chamber is maintained at a pressure in a range of from 5 millitorr to 100 Torr (Paragraph [0049]) and a temperature of less than or equal to 500 °C. (Paragraph [0048]). In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976). MPEP 2144.05(I)
With regards to claims 17-18, the modified teachings of Li renders obvious purging the semiconductor processing chamber with a purge gas, wherein the purge gas includes one or more of argon (Ar), helium (He), krypton (Kr), neon (Ne), xenon (Xe), hydrogen (H2), oxygen (O2), or nitrogen (N2). (Paragraph [0045]).
Claim 19 is rejected under 35 U.S.C. 103 as being unpatentable over LI et al (U.S. Patent Application Publication 2019/0326123) in view of KAL et al (U.S. Patent Application Publication 2017/0271165).
With regards to claim 19, Li discloses a method comprising flowing a precursor comprising on or more an halogen containing species wherein the halogen contain species comprises one or more fluorine (F2) or xenon difluoride, into a semiconductor processing chamber containing a substrate; exposing the substrate to the precursor and etching the substrate, the substrate having a plurality of alternating layer of silicon and silicon containing layer thereon, wherein the silicon layers are selectively etched relative to the silicon containing dielectric layers (Paragraphs [0042]-[0045]).
Li does not explicitly discloses exposing the substrate to the activated species; and etching the substrate, the substrate having a plurality of alternating layers of silicon and silicon germanium thereon, wherein the silicon layers are selectively etched relative to the silicon germanium layers.
However Li discloses wherein during etching a plasma may be generated (Paragraphs [0027], [0036]) or plasma free operation wherein the precursors are in a state where they possess energetically favorable etch reaction pathway wherein the process conditions are performed at a higher temperature to provide higher etch rates (Paragraphs [0041]-[0048]). Kal discloses a method of selectively etching silicon to a layer of silicon germanium wherein the radical species of a fluorine containing gas can be used to etch silicon at a higher etch rate than silicon germanium (Paragraphs [0026]-[0031]). As such Li as modified by Ka renders obvious exposing the substrate to the activated species; and etching the substrate, the substrate having a plurality of alternating layers of silicon and silicon germanium thereon, wherein the silicon layers are selectively etched relative to the silicon germanium layers.
It would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the invention to modify the embodiment of Li to include the activation as rendered obvious by Li because the reference of Li teaches activating the precursors provide precursors in a state wherein higher etch rates are provided (Paragraph [0048]) and one of ordinary skill in the art prior to the effective filing date of the invention would have had a reasonable expectation of predictably achieving the desired etching using the activated species as rendered obvious by the teachings of Li MPEP 2143D
It would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the invention to modify the teachings of Li to include the silicon germanium as rendered obvious by Kal because one of ordinary skill in the art prior to the effective filing date of the invention would have had a reasonable expectation of predictably achieving the desired etching using the silicon germanium layer as rendered obvious by the teachings of Kal MPEP 2143D
Allowable Subject Matter
Claim13 is objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Claim 19 is allowed.
The following is a statement of reasons for the indication of allowable subject matter:
With regards to claim 13, Li has been cited as the closest prior art. However the cited prior art fails to teach or render obvious Applicant’s claimed limitation of forming an activated species heating the substrate to a temperature of less than or equal to 500 °C using an optical radiation source, wherein the activated species is generated by UV radiation. A further search of the prior art has failed to produce analogous art which teaches or renders obvious Applicant’s claimed invention.
With regards to claim 19, Li has been cited as the closest prior art, however the cited prior art fails to teach or render obvious “… forming an activated species of the precursor; exposing the substrate to the activated species; and etching the substrate, the substrate having a plurality of alternating layers of silicon and silicon germanium thereon, and alternating silicon oxide layers and silicon nitride layers in contact with the alternating silicon layers and silicon germanium layers, wherein the silicon layers are selectively etched relative to the silicon oxide layers and the silicon nitride layers.” . A further search of the prior art has failed to produce analogous art which teaches or renders obvious Applicant’s claimed invention.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to STEPHANIE P. DUCLAIR whose telephone number is (571)270-5502. The examiner can normally be reached 9-6:30 M-F.
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/STEPHANIE P DUCLAIR/Primary Examiner, Art Unit 1713
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