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 § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 3, 7, 11, 16 and 23-25 are rejected under 35 U.S.C. §112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor regards as the invention.
Unclear temperature range—claim 11
Claim 9 recites “exposing the substrate to the gas-phase L-type ligand while the substrate is exposed to a temperature ranging between 25°C and 400°C.” Claim 11, which depends from claim 9, recites “exposing the substrate to carbon monoxide (CO) while the substrate is exposed to a temperature less than 75°C.”
It is unclear whether claim 11 requires a temperature ranging from 25°C to less than 75°C, thereby retaining the lower temperature limit of claim 9, or replaces the temperature range of claim 9 with a range encompassing any temperature less than 75°C, including temperatures below 25°C. Because these interpretations result in different temperature ranges, the metes and bounds of claim 11 are unclear.
For purposes of examination, claim 11 is interpreted as requiring a temperature ranging from 25°C to less than 75°C.
Unclear relationship between the metal surface and the ruthenium surface—claims 7 and 11
Claim 1 recites “a metal surface” exposed on a surface of the substrate. Claims 7 and 11 subsequently recite “a ruthenium surface” exposed on the surface of the substrate.
It is unclear whether “a ruthenium surface” is the previously recited “a metal surface,” wherein the metal surface is further limited to a surface of a ruthenium layer, or whether “a ruthenium surface” identifies a different or additional surface. Therefore, the number and identity of the surfaces upon which the claimed method is performed are unclear.
For purposes of examination, “a ruthenium surface” in claims 7 and 11 is interpreted as referring to the “metal surface” recited in claim 1.
Unclear role of the second purge solution—claims 3 and 16
Claim 3 recites “rinsing the substrate with a second purge solution to remove the second etch solution from the surface of the substrate and etch the metal layer.” Claim 16 similarly recites “rinsing the substrate with a second purge solution to remove the second etch solution from the surface of the substrate and etch the ruthenium layer.”
It is unclear whether the second purge solution itself both removes the second etch solution and etches the metal or ruthenium layer, or whether the second purge solution merely removes the second etch solution and associated reaction products, thereby completing an etch cycle in which the preceding surface-modification and dissolution steps etch the layer. Because the claims do not clearly identify whether the purge solution itself performs the etching, the relationship between the rinsing and etching functions is unclear.
For purposes of examination, claims 3 and 16 are interpreted as requiring the second purge solution to remove the second etch solution and associated reaction products, thereby completing the wet atomic layer etching cycle, rather than requiring the second purge solution itself to chemically etch the metal or ruthenium layer.
Unclear identity of the ligand-derived passivation layer—claims 11, 23, and 24
Claim 1 recites forming “a passivation layer” by exposing the substrate to a gas-phase L-type ligand. Claim 11 subsequently recites forming “a carbonyl passivation layer” by exposing the substrate to carbon monoxide.
Claim 16 similarly recites forming “a passivation layer” by exposing the substrate to a gas-phase L-type ligand. Claims 23 and 24 subsequently recite forming “a carbonyl passivation layer” by exposing the substrate to carbon monoxide.
It is unclear whether the carbonyl passivation layer is the previously recited passivation layer, further limited by the dependent claim to a carbonyl passivation layer formed using carbon monoxide, or whether the dependent claims require formation of a new or additional carbonyl passivation layer. Therefore, the number and identity of the claimed passivation layers are unclear.
For purposes of examination, the carbonyl passivation layer recited in claim 11 is interpreted as the passivation layer recited in claim 1, and the carbonyl passivation layer recited in claims 23 and 24 is interpreted as the passivation layer recited in claim 16.
Unclear referent for “the passivation layer”—claims 16-25
Claim 16 recites both:
“a passivation layer” formed by exposing the substrate to a gas-phase L-type ligand; and
“a ruthenium chloride or oxychloride passivation layer” formed by exposing the ruthenium surface to a first etch solution.
Claim 16 thereafter recites “wherein the passivation layer formed on the ruthenium surface increases an etch rate of the ruthenium layer,” and claim 25 recites “wherein the passivation layer formed on the ruthenium surface prevents formation of ruthenium dioxide (RuO2) and/or other ruthenium species having oxidation states higher than 3+.”
Because both previously recited layers are passivation layers formed on the ruthenium surface, it is unclear whether “the passivation layer” in claims 16 and 25 refers to the gas-phase-L-type-ligand-derived passivation layer or the ruthenium chloride or oxychloride passivation layer formed during the wet atomic layer etching cycles. These interpretations attribute the recited increased etch rate and oxidation-prevention functions to different layers formed at different stages of the method. Therefore, the referent of “the passivation layer” and the metes and bounds of claims 16 and 25 are unclear.
For purposes of examination, “the passivation layer” in the final wherein clause of claim 16 and in claim 25 is interpreted as referring to the passivation layer formed by exposing the substrate to the gas-phase L-type ligand.
Claim 17-25 are rejected as being dependent on an indefinite claim.
The following is a quotation of 35 U.S.C. 112(d):
(d) REFERENCE IN DEPENDENT FORMS.—Subject to subsection (e), a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
The following is a quotation of pre-AIA 35 U.S.C. 112, fourth paragraph:
Subject to the following paragraph [i.e., the fifth paragraph of pre-AIA 35 U.S.C. 112], a claim in dependent form shall contain a reference to a claim previously set forth and then specify a further limitation of the subject matter claimed. A claim in dependent form shall be construed to incorporate by reference all the limitations of the claim to which it refers.
Claim 11 is rejected under 35 U.S.C. §112(d) as being of improper dependent form for failing to clearly further limit the subject matter of the claim upon which it depends.
Claim 11 depends from claim 9. Claim 9 recites “exposing the substrate to the gas-phase L-type ligand while the substrate is exposed to a temperature ranging between 25°C and 400°C.” Claim 11 recites “exposing the substrate to carbon monoxide (CO) while the substrate is exposed to a temperature less than 75°C.” The temperature range recited in claim 11 facially encompasses temperatures below the 25°C lower limit required by claim 9 and therefore does not clearly retain and further limit the temperature range of claim 9.
Applicant may cancel claim 11, amend claim 11 to place the claim in proper dependent form, rewrite claim 11 in independent form, or present a sufficient showing that claim 11 complies with the statutory requirements.
Allowable Subject Matter
Claims 1, 2, 4-6, 8-10, and 12-15 are allowed.
Claims 3 and 7 would be allowable if rewritten or amended to overcome the rejection under 35 U.S.C. §112(b) set forth in this Office action.
Claim 11 would be allowable if rewritten or amended to overcome the rejections under 35 U.S.C. §§112(b) and 112(d) set forth in this Office action.
Claim 16 would be allowable if rewritten or amended to overcome the rejection under 35 U.S.C. §112(b) set forth in this Office action.
Claims 17-22 are objected to as being dependent upon rejected base claim 16, but would be allowable if rewritten in independent form including all of the limitations of claim 16 and any intervening claims, with the indefiniteness identified with respect to claim 16 corrected.
Claims 23-25 would be allowable if claim 16 and claims 23-25 were amended to overcome the rejections under 35 U.S.C. §112(b) set forth in this Office action.
The following is an examiner’s statement of reasons for allowance and indication of allowable subject matter:
Regarding claim 1, Dordi et al. (US 2014/0154406 A1) teaches “receiving a substrate having the metal layer formed thereon, wherein a metal surface is exposed on a surface of the substrate” (a ruthenium layer having an exposed ruthenium surface; paragraphs [0042]-[0045], Figs. 1A-1C). Dordi further teaches “annealing the substrate in a reducing atmosphere to at least partially reduce the metal surface” (ruthenium oxide on the exposed ruthenium surface is reduced to metallic ruthenium using a dry reduction pretreatment comprising a forming-gas anneal at approximately 250°C to 300°C; paragraphs [0045]-[0047]).
Dordi does not teach “exposing the substrate to a gas-phase L-type ligand to form a passivation layer on the metal surface” or subsequently “etching the metal layer using a wet etch process, wherein the passivation layer formed on the metal surface increases an etch rate of the metal layer during the wet etch process, compared to an etch rate achieved without the passivation layer.”
Abel et al. (US 2023/0118554 A1) teaches wet etching a ruthenium metal layer by performing a cyclic wet atomic layer etching process in which a ruthenium surface is chemically modified to form a self-limiting ruthenium halide, oxyhalide, or salt passivation layer that is subsequently selectively removed (paragraphs [0057], [0059], and [0061]-[0062]).
Abel does not teach annealing the substrate in a reducing atmosphere to at least partially reduce the metal surface and thereafter “exposing the substrate to a gas-phase L-type ligand to form a passivation layer on the metal surface,” wherein the ligand-derived passivation layer increases the etch rate during the subsequent wet etch process compared to an etch rate achieved without the passivation layer.
Accordingly, the prior art of record, whether alone or in combination, fails to teach or suggest:
“annealing the substrate in a reducing atmosphere to at least partially reduce the metal surface; exposing the substrate to a gas-phase L-type ligand to form a passivation layer on the metal surface; and etching the metal layer using a wet etch process, wherein the passivation layer formed on the metal surface increases an etch rate of the metal layer during the wet etch process, compared to an etch rate achieved without the passivation layer,”
in the context of the remaining limitations of claim 1.
Claims 2, 4-6, and 8-10 are allowed at least based on their dependency from claim 1. Claims 3, 7, and 11 contain allowable subject matter at least based on their dependency from claim 1, subject to the rejections under 35 U.S.C. §112 set forth above.
Regarding claim 12, Dordi teaches “receiving a substrate having the ruthenium layer formed thereon, wherein a ruthenium surface is exposed on a surface of the substrate” and “annealing the substrate in a reducing atmosphere to at least partially reduce the ruthenium surface” (ruthenium oxide on an exposed ruthenium surface is reduced to metallic ruthenium using a forming-gas anneal at approximately 250°C to 300°C; paragraphs [0042]-[0047], Figs. 1A-1C).
Dordi does not teach “exposing the substrate to a carbon monoxide (CO) gas to form a carbonyl passivation layer on the ruthenium surface” or subsequently “etching the ruthenium layer using a wet etch process, wherein the carbonyl passivation layer formed on the ruthenium surface increases an etch rate of the ruthenium layer during the wet etch process, compared to an etch rate achieved without the carbonyl passivation layer.”
Abel teaches wet etching a ruthenium layer by cyclically forming and selectively removing a self-limiting ruthenium halide, oxyhalide, or salt passivation layer from the ruthenium surface (paragraphs [0057], [0059], and [0061]-[0062]).
Abel does not teach annealing the substrate in a reducing atmosphere to at least partially reduce the ruthenium surface and thereafter “exposing the substrate to a carbon monoxide (CO) gas to form a carbonyl passivation layer on the ruthenium surface,” wherein the carbonyl passivation layer increases the etch rate during the subsequent wet etch process compared to an etch rate achieved without the carbonyl passivation layer.
Accordingly, the prior art of record, whether alone or in combination, fails to teach or suggest:
“annealing the substrate in a reducing atmosphere to at least partially reduce the ruthenium surface; exposing the substrate to a carbon monoxide (CO) gas to form a carbonyl passivation layer on the ruthenium surface; and etching the ruthenium layer using a wet etch process, wherein the carbonyl passivation layer formed on the ruthenium surface increases an etch rate of the ruthenium layer during the wet etch process, compared to an etch rate achieved without the carbonyl passivation layer,”
in the context of the remaining limitations of claim 12.
Claims 13-15 are allowed at least based on their dependency from claim 12.
Regarding claim 16, Abel teaches “etching the ruthenium layer by performing multiple cycles of the wet ALE process,” wherein each cycle includes exposing the ruthenium surface to a first etch solution comprising a chlorinating agent dissolved in a non-aqueous solvent to form a self-limiting and insoluble ruthenium chloride passivation layer; rinsing the substrate with a first purge solution; exposing the modified ruthenium surface layer to a second etch solution to selectively dissolve the modified layer and expose the underlying ruthenium surface; rinsing the substrate with a second purge solution; and repeating the cycle to etch the ruthenium layer (paragraphs [0057]-[0062] and [0101]-[0105], Figs. 9-10).
Abel does not teach, before performing the wet atomic layer etching cycles, “annealing the substrate in a reducing atmosphere to at least partially reduce the ruthenium surface” and thereafter “exposing the substrate to a gas-phase L-type ligand to form a passivation layer on the ruthenium surface,” wherein the ligand-derived passivation layer increases the etch rate during the wet atomic layer etching process compared to an etch rate achieved without the passivation layer.
Dordi teaches “receiving a substrate having the ruthenium layer formed thereon, wherein a ruthenium surface is exposed on a surface of the substrate” and “annealing the substrate in a reducing atmosphere to at least partially reduce the ruthenium surface” (ruthenium oxide on an exposed ruthenium surface is reduced to metallic ruthenium using a forming-gas anneal at approximately 250°C to 300°C; paragraphs [0042]-[0047], Figs. 1A-1C).
Dordi does not teach “exposing the substrate to a gas-phase L-type ligand to form a passivation layer on the ruthenium surface,” performing the recited multiple cycles of the wet atomic layer etching process, or that the ligand-derived passivation layer increases the etch rate during the wet atomic layer etching process compared to an etch rate achieved without the passivation layer.
Accordingly, the prior art of record, whether alone or in combination, fails to teach or suggest:
“annealing the substrate in a reducing atmosphere to at least partially reduce the ruthenium surface; exposing the substrate to a gas-phase L-type ligand to form a passivation layer on the ruthenium surface; and etching the ruthenium layer by performing multiple cycles of the wet ALE process,”
wherein:
“the passivation layer formed on the ruthenium surface increases an etch rate of the ruthenium layer during said etching, compared to an etch rate achieved without the passivation layer,”
in the context of the remaining limitations of claim 16.
Claims 17-25 contain allowable subject matter at least based on their dependency from claim 16, subject to the objections and rejections under 35 U.S.C. §112 set forth above.
Conclusion
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/JONATHAN L CARTER/Examiner, Art Unit 1713
/ERIN F BERGNER/Primary Examiner, Art Unit 1713
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