DETAILED ACTION
Claims 1-19 and 21 are pending before the Office for review.
In the response filed October 24, 2025:
Claim 20 was canceled.
Claim 21 was newly added.
No new matter is present.
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 .
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1-6, 14-19 and 21 are rejected under 35 U.S.C. 103 as being unpatentable over ROBERTS et al (U.S. Patent 10,361,092) in view of KANARIK et al (U.S. Patent Application Publication 2021/0005472) and DOLE et al (U.S. Patent Application Publication 2020/0126804).
With regards to claim 1, Roberts discloses an etching method including proving a substrate comprising a silicon containing film (412) and a mask (416), the mask being provided on the silicon containing film (412) and performing a cyclic process with a plurality of cycles of a first etch phase with an etch gas comprising metal containing component and a second etch phase with an etch gas without a metal containing component wherein the metal component comprises tungsten and a etch gas comprises a free fluorine providing gas (Col 3 lines 39-57 Col. 4 lines 56-67, Col 5 lines 1-60 Col. 6 lines 60-Col. 7 lines 11 Col 7 lines 34-41).
Roberts does not explicitly disclose the silicon-containing film including a recess, the mask being provided on the silicon-containing film and including an opening that exposes the recess; (b) forming a carbon-containing film on a side wall of the silicon-containing film, the side wall defining the recess; and (c) by using a plasma generated from a processing gas, forming a protective film containing tungsten on the carbon-containing film and etching the silicon-containing film in the recess, the processing gas including a fluorine-containing gas and a tungsten-containing gas.
Dole discloses (a) preparing a substrate, the substrate comprising a silicon-containing film (103) and a mask (106), the silicon-containing film including a recess (102), the mask being provided on the silicon-containing film and including an opening that exposes the recess (Figure 3); (b) forming a passivation layer (107) wherein the passivation layer may be a mixed layer that formed from a tungsten containing material and carbon containing material where in the layer may be s single mixed ,layer or may be two passivating layers which may over lap one another (Paragraphs [0016]-[0033] ) which renders obvious ; (b) forming a carbon-containing film on a side wall of the silicon-containing film, the side wall defining the recess; and (c) by using a plasma generated from a processing gas, forming a protective film containing tungsten on the carbon-containing film and etching the silicon-containing film in the recess, the processing gas including a fluorine-containing gas and a tungsten-containing gas.
Kanarik discloses an etching method comprising etching a silicon containing layer with a mask using a plasma generated from a processing gas wherein the silicon containing layer is etched while the sidewalls are passivated wherein the gases used in the etching process may also be used in depositing on the features, the processing gas including a fluorine containing gas and a tungsten containing gas and the tungsten containing gas could form deposits while etching (Paragraphs[0030]-[0032], [0049]-[0053]).
As such Roberts as modified by Dole and Kanarik renders obvious an etching method including:(a) preparing a substrate, the substrate comprising a silicon-containing film and a mask, the silicon-containing film including a recess, the mask being provided on the silicon-containing film and including an opening that exposes the recess (Roberts Col 3 lines 39-57, Dole Paragraphs [0016]-[0029]); (b) forming a carbon-containing film on a side wall of the silicon-containing film, the side wall defining the recess (Dole Paragraphs [0016]-[0033] discloses forming a passivation layer comprising two layers of different material wherein one layer is a carbon layer and the second layer is a tungsten containing layer Roberts Col. 5 lines 4-36, Col. 6 lines 60-Col. 7 line 11 discloses independent etching step without metal precursor with fluorocarbon component); and (c) by using a plasma generated from a processing gas, forming a protective film containing tungsten on the carbon-containing film and etching the silicon-containing film in the recess, the processing gas including a fluorine-containing gas and a tungsten-containing gas (Roberts Col. 4 lines 56-67, Col 5 lines 1-60 Col. 6 lines 60-Col. 7 lines 11 Col 7 lines 34-41 discloses etching step using metal containing component Kanarik Paragraphs[0030]-[0032], [0049]-[0053] discloses performing cryogenic etching with metal (tungsten) containing precursor and fluorine precursor will etch silicon containing layer and deposit metal layer on sidewalls Dole Paragraphs [0016]-[0033] discloses forming a passivation layer comprising two layers of different material wherein one layer is a carbon layer and the second layer is a tungsten containing layer).
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 method of Roberts to include the carbon coating and protective layer deposition as rendered obvious by Dole because the reference of Dole teaches that the tungsten based polymer film promotes a uniform etch rate hen etching the recess and preventing notching during etching (Paragraph [0009]) 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 sidewall passivation as rendered obvious by Dole. 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 method of Roberts to include the etching and protective layer deposition as rendered obvious by Kanarik because the reference of Kanarik teaches that such deposition and etching allows for increasing etch rates at the bottom while protecting the mask and upper surfaces (Paragraph [0029]) 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 etching and sidewall passivation as rendered obvious by Kanarik. MPEP 2143D
With regards to claim 2, the modified teachings of Roberts renders obvious wherein in (b), the carbon-containing film is formed from a side wall of the mask that defines the opening to at least a portion of the side wall of the silicon-containing film (Dole Paragraph [0017]-[0033] discloses forming passivation layer 107 on the sidewalls of the opening where in the thickness and location of the passivation layer can be adjusted)
With regards to claims 3-4, the modified teachings of Roberts renders obvious wherein in (b), the carbon-containing film is not formed on a bottom surface of the silicon-containing film that defines the recess and wherein in (b), the carbon-containing film is also formed on a bottom surface of the silicon-containing film that defines the recess (Dole Paragraph [0017]-[0033] discloses wherein the passivation layer 107 is a fluorocarbon and tungsten containing layer where in each layer may comprise both or a single material wherein the concentration of the carbon and the tungsten containing material may be formed at different amounts towards the top and bottom of the recess).
With regards to claim 5, the modified teachings of Roberts renders obvious wherein in (b), the protective film (310) is preferentially formed on the carbon-containing film (304) on the side wall of the silicon-containing film (303) (Dole Paragraphs [0016]-[0033] discloses forming a passivation layer comprising two layers of different material wherein one layer is a carbon layer and the second layer is a tungsten containing layer).
With regards to claim 6, the modified teachings of Roberts renders obvious wherein a cycle including (b) and (c) is repeated a plurality of times (Roberts Col. 6 lines 63- Col. 7 line 11).
With regards to claim 14, the modified teachings of Roberts renders obvious wherein in (c), the fluorine-containing gas includes at least one of a hydrogen fluoride gas and a hydrofluorocarbon gas.(Kanarik Paragraph [0030]).
With regards to claim 15, the modified teachings of Roberts renders obvious wherein in (c), the processing gas further includes a phosphorus-containing gas. (Kanarik Paragraph [0030] discloses phosphorus pentafluoride).
With regards to claim 16, the modified teachings of Roberts renders obvious wherein in (c), the processing gas further contains a carbon-containing gas. (Roberts Col. 5 lines 4-36, Col. 6 lines 60-67).
With regards to claim 17, the modified teachings of Roberts renders obvious wherein in (c), a temperature of a substrate support that supports the substrate is 00C or lower (Roberts Col. 4 lines 56-65, Col. 6 lines 62-63, Kanarik Paragraph [0014], [0047]).
With regards to claim 18, the modified teachings of Roberts renders obvious wherein the silicon-containing film is a silicon oxide film, a silicon nitride film, a polycrystalline silicon film, or a film stack containing two or more of the silicon oxide film, the silicon nitride film, and the polycrystalline silicon film (Roberts Col. 3 lines 56-57, Col. 5 lines37-55).
With regards to claim 19, the modified teachings of Roberts renders obvious wherein the mask is a carbon-containing film (Roberts Col. 3 lines 46-48, Col. 5 lines 53-54).
With regards to claim 21, the modified teachings of Roberts renders obvious wherein the carbon containing film is formed by generating a plasma from a CH-based gas (Roberts Col. 5 lines 4-36, Col. 6 lines 60-67 Dole Paragraph [0031]).
Allowable Subject Matter
Claims 7-13 are 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.
The following is a statement of reasons for the indication of allowable subject matter: The Examiner previously rejected the subject matter of claim 7 under Roberts in view of Colinjivadi and Kanarik. However Applicant’s amendment and arguments filed October 24, 2025 have overcome the rejection of record. In particular, the cited prior art fails to teach or render obvious an etching method including:(a) preparing a substrate, the substrate comprising a silicon-containing film and a mask, the silicon-containing film including a recess, the mask being provided on the silicon-containing film and including an opening that exposes the recess; (b) forming a carbon-containing film on a side wall of the silicon-containing film, the side wall defining the recess; and (c) by using a plasma generated from a processing gas, forming a protective film containing tungsten on the carbon-containing film and etching the silicon-containing film in the recess, the processing gas including a fluorine-containing gas and a tungsten-containing gas, wherein (b) is executed in a first chamber, and (c) is executed in a second chamber different from the first chamber. A search of the cited prior art has failed to produce analogous art which teaches or renders obvious Applicant’s claimed invention.
Conclusion
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/STEPHANIE P DUCLAIR/Primary Examiner, Art Unit 1713