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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 09/02/2025 has been entered.
Priority
Examiner notes that in the office action mailed on 01/13/2025 this application was improperly listed as having a claim to foreign priority. Please note that this application has not claimed foreign priority – as indicated by the Office Action Summary attached to this action.
Status of the Claims
This is a non-final office action in response to the applicant’s arguments and remarks filed on 09/02/2025. Claims 1-13, 19-22, and 24-26 are pending in the current office action. Claims 1 and 19 have been amended by the applicant. Claims 24-26 are new claims. Claims 14-18 and 23 are cancelled.
Status of the Rejection
All 35 U.S.C. § 103 rejections from the previous office action are substantially maintained and modified only in response to the amendments to the claims.
New grounds of rejection under 35 U.S.C. § 103 are necessitated by the amendments.
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 1-11, 13, and 19-22 are rejected under 35 U.S.C. 103 as being unpatentable over Wyse et al. (US-20140060574-A1) in view of Yu et al. (US-20190237341-A1).
Regarding Claim 1, Wyse teaches a method of cleaning a process chamber (Paragraph [0005]), the method comprising:
(a) providing a process chamber having a layer of tin oxide on at least some parts of the process chamber (Paragraph [0005] methods for cleaning process chambers used in depositing metal oxide films. [abstract] methods for the removal of tin oxide. Paragraph [0027] cleaning on a process chamber when an undesired amount of contaminants exist on the process chamber);
(b) exposing the tin oxide layer in the process chamber to a process gas comprising a hydrogen (H2) (Paragraph [0029] gas mixture used in cleaning can include H2) to convert at least a portion of the tin oxide layer to a volatile compound (Paragraph [0033] cleaning gas mixture reacts with the contaminants to form a gas-phase reaction product).
Wyse fails to teach exposing the tin oxide layer in the process chamber to a process gas that comprises both a hydrocarbon and hydrogen wherein the exposure of the tin oxide layer to the process gas comprising a hydrocarbon and hydrogen (H2) further results in a formation of a non-volatile carbon-containing polymer and wherein a molar ratio of hydrogen (H2) and the hydrocarbon is between 1:15 and 1:25.
Yu teaches a method to remove tin oxide material from a substrate within a process chamber (Paragraph [0014]). Yu teaches exposing tin oxide to a process gas comprising a hydrocarbon and hydrogen (Paragraph [0043] exposing tin oxide to a hydrogen-containing reactant such that it converts tin oxide to a volatile tin hydride. Hydrogen-containing reactants include H2 and hydrocarbons, and mixtures of these can be used. Paragraph [0049] the process gas may consist essentially of H2, inert gas, and a hydrocarbon). Yu teaches that the process gas forms a carbon-containing polymer on the surface during the etch (Paragraph [0062] the process gas forms a carbon-containing polymer on the surface during the etch). Yu teaches embodiments where the process gas contains a molar ratio of hydrogen to hydrocarbon of 1:0 to 1:18.4 (Paragraphs [0050-0054] embodiments are taught where the flow rate of H2 can be 25 to 700 sccm and the flow rate of CH4 can be 0 to 500 sccm. This teaches a range of a flow rate ratio of H2:CH4 from 1:0 to 1:20. CH4 has a molecular weight of 16.0425 and a density under standard conditions of 0.657 g/L. H2 has a molecular weight of 2.01588 and a density under standard conditions of 0.08988g/L. Converting the flow rate ratio to a molar ratio, results in a molar ratio range of 1:0 to 1:18.4).
It would have been obvious to one of ordinary skill in the art to have modified the method of Wyse such that the process gas used to react with the tin oxide comprised both hydrogen and a hydrocarbon and that this process gas would then form a carbon-containing polymer during the etch process.
It would have been obvious to one of ordinary skill in the art to have selected and incorporated flow rates for H2 and the hydrocarbon with the ranges taught such that the resulting molar ratio within the disclosed range of 1:0 to 1:18.4, including at amounts that overlap with the claimed range of 1:15 to 1:25. It has been held that obviousness exists where the claimed ranges overlap or lie inside ranges disclosed by the prior art. See MPEP 2144.05 (I).
This modification would have been obvious as it would have been the combination of prior art elements according to known methods to yield predictable results. Using the process gas and forming a carbon-containing polymer as taught by Yu within the method taught by Wyse would have had the predictable result of removing the tin oxide while forming a carbon-containing polymer. See MPEP 2143(I)(A).
Wyse also fails to teach (c) removing the carbon-containing polymer by exposing the carbon- containing polymer to an oxygen-containing reactant or to H2, wherein exposure to H2 is performed in an absence of hydrocarbon. However, Wyse does teach a two-step method of cleaning a process chamber, where the first step creates a non-volatile reaction product and the second step removes the non-volatile reaction product (Paragraph [0034] “cycling two different chamber clean chemistries into the chamber sequentially” and “second chamber clean chemistry reacts with the first non-volatile products to form more volatile products that can be more easily removed from the chamber”).
Yu teaches a method to remove tin oxide material from a substrate within a process chamber (Paragraph [0014]). Yu teaches a method of removing carbon-containing materials by using an oxygen-containing reactant (Paragraph [0076] materials including carbon-containing compounds and polymers are etched using an oxygen-containing reagent). Yu further teaches a method where after a tin oxide layer is etched, a carbon-containing layer is removed using oxygen-based chemistry (Paragraph [0099], Figures 4A-4E an exemplary method where after a blanket tin oxide layer (element 407) is etched a carbon layer (element 405) is removed using oxygen-based chemistry).
It would have been obvious to one of ordinary skill in the art to have modified the method of Wyse such that the second cleaning step used to remove the non-volatile products created in the first step utilized the etching process that used an oxygen-containing reactant as taught by Yu.
This modification would have been obvious because it would have been the combination of prior art elements according to known methods to yield predictable results. Yu teaches a process to remove a carbon-containing material, and the combination would have had the predictable result of removing the carbon-containing polymer. See MPEP 2143(I)(A).
Regarding Claim 2, Yu further teaches wherein the carbon-containing polymer is removed in (c) by exposing the carbon-containing polymer to the oxygen-containing reactant (Paragraph [0076] materials including carbon-containing compounds and polymers are etched using an oxygen-containing reagent. See the rejection of claim 1).
Regarding Claim 3, Yu further teaches wherein the carbon-containing polymer is removed in (c) by exposing the carbon-containing polymer to the oxygen-containing reactant selected from the group consisting of 02 and 03. (Paragraph [0076] materials including carbon-containing compounds and polymers are etched using an oxygen-containing reagent. Where O2 and O3 are listed as suitable reagents. See the rejection of claim 1).
Regarding Claim 4, Yu further teaches wherein the oxygen-containing reactant is plasma-activated 02 (Paragraph [0076] materials including carbon-containing compounds and polymers are etched using an oxygen-containing reagent. Where O2 is listed as a suitable reagent and the reagents can be plasma-activated. See the rejection of claim 1).
Regarding Claim 5, Yu further teaches wherein the oxygen-containing reactant is O3 (Paragraph [0076] materials including carbon-containing compounds and polymers are etched using an oxygen-containing reagent. Where O3 is listed as a suitable reagent. See the rejection of claim 1).
Regarding Claim 6, Wyse teaches a method of cleaning process chambers that includes repeatedly using two different chemistries in the chamber one after the other (Paragraph [0034] “cycling two different chamber clean chemistries into the chamber sequentially”).
Regarding Claim 7, modified Wyse teaches all the limitations of claim 1 as outlined above.
Wyse fails to teach that the method further comprises purging the process chamber after (b).
Yu further teaches that the volatile reaction products of tin oxide can be removed from the process chamber by purging (Paragraph [0049], volatile materials created from the etch reaction of tin oxide with hydrogen can be easily removed from the process chamber by purging).
It would have been obvious to one of ordinary skill in the art to have modified the method of Wyse such that following step (b) a purge was conducted to remove the volatile materials created during (b), as taught by Yu.
This modification would have been obvious as it would have been the combination of prior art elements according to known methods to yield predictable results. Including the purge taught by Yu would have had the predictable result of removing the volatile reaction products formed during step (b). See MPEP 2143(I)(A).
Regarding Claims 8 and 9, Wyse further teaches that the process chamber comprises metal parts, as required by claim 8, and that the process chamber comprises aluminum parts, as required by claim 9 (Wyse Paragraph [0077] the interior wall of the process chamber can be made of aluminum, which is a metal).
Regarding Claims 10 and 11, Wyse further teaches that the process chamber is selected from the group consisting of an ALD chamber, a CVD chamber, and a PVD chamber, as required by claim 10, and that the process chamber is a PEALD chamber or a PECVD chamber, as required by claim 11 (Wyse Paragraph [0015] the processing chamber can be for Plasma Enhanced ALD (PEALD)).
Regarding Claim 13, modified Wyse teaches all the limitations of claim 1 as outlined above.
Wyse is silent about the processing temperature of the oxygen-containing based etching process that is used to remove carbon-containing material and therefore fails to teach that (c) comprises heating the process chamber during removal of the carbon-containing polymer, as required by the instant claim.
However, Yu teaches that the temperature during processing can vary depending on the specific recipe being used, the chuck can be operated at elevated temperatures, and that the etching processes can be conducted at temperatures of 100°C or less (Paragraph [0122]).
It would have been obvious to one of ordinary skill in the art to have used an elevated temperature for step (c) thereby including heating the process chamber during removal of the carbon-containing polymer.
This modification would have been obvious as it would have been the combination of prior art elements according to known methods to yield predictable results. Applying heating to the process chamber during step (c) would have had the predictable result of allowing step (c) to be conducted at an elevated temperature. See MPEP 2143(I)(A).
Regarding Claim 19, Yu teaches a method for etching a tin oxide layer on a semiconductor substrate (Paragraph [0028] methods of semiconductor device manufacturing are taught, where some embodiments include etching tin oxide), the method comprising:
(a) providing a semiconductor substrate having an exposed layer of tin oxide (Paragraph [0099], Figure 4C, where the semiconductor substrate comprises elements 401, 403, 405, 407, 409, and 411 and element 407 is a layer of tin oxide that has some exposed areas);
(b) contacting the exposed tin oxide layer in a process chamber to a process gas comprising a hydrocarbon and hydrogen (H2) to convert at least a portion of the tin oxide layer to a volatile compound (Paragraph [0043] exposing tin oxide to a hydrogen-containing reactant such that it converts tin oxide to a volatile tin hydride. Hydrogen-containing reactants include H2 and hydrocarbons, and mixtures of these can be used. Paragraph [0049] the process gas may consist essentially of H2, inert gas, and a hydrocarbon. Paragraph [0099], Figures 4A-4E an exemplary method where a blanket tin oxide layer (element 407) is etched),
wherein the contacting of the tin oxide layer to the process gas comprising a hydrocarbon and hydrogen (H2) further results in a formation of a non-volatile carbon-containing polymer (Paragraph [0062] the process gas forms a carbon-containing polymer on the surface during the etch); and
Yu teaches a method of removing carbon-containing materials by using an oxygen-containing reactant (Paragraph [0076] materials including carbon-containing compounds and polymers are etched using an oxygen-containing reagent). Yu further teaches where after a tin oxide layer is etched a carbon-containing layer is removed using oxygen-based chemistry (Paragraph [0099], Figures 4A-4E an exemplary method where after a blanket tin oxide layer (element 407) is etched a carbon layer (element 405) is removed using oxygen-based chemistry).
Yu fails to explicitly teach wherein a molar ratio of hydrogen (H2) to the hydrocarbon is between 1:15 to 1:25.
However, Yu teaches embodiments where the process gas contains a molar ratio of hydrogen to hydrocarbon of 1:0 to 1:18.4 (Paragraphs [0050-0054] embodiments are taught where the flow rate of H2 can be 25 to 700 sccm and the flow rate of CH4 can be 0 to 500 sccm. This teaches a range of a flow rate ratio of H2:CH4 from 1:0 to 1:20. CH4 has a molecular weight of 16.0425 and a density under standard conditions of 0.657 g/L. H2 has a molecular weight of 2.01588 and a density under standard conditions of 0.08988g/L. Converting the flow rate ratio to a molar ratio (20*0.657*(1/16.0425)*(1/0.08988)*2.01588 =18.4), results in a molar ratio range of 1:0 to 1:18.4.)
Yu fails to teach removing the carbon-containing polymer formed during the etching of the tin oxide layer by exposing the carbon-containing polymer to an oxygen-containing reactant.
Wyse teaches a method of cleaning process chambers that includes using two different chemistries in the chamber one after the other (Paragraph [0034] “cycling two different chamber clean chemistries into the chamber sequentially”). Wyse teaches that this method is useful in using the second chemistry remove non-volatile products that were created from the first chemistry (Paragraph [0034] “second chamber clean chemistry reacts with the first non-volatile products to form more volatile products that can be more easily removed from the chamber”).
It would have been obvious to one of ordinary skill in the art to have modified the method of Yu such that after the formation of a carbon-containing polymer during the etching of the tin oxide, that carbon-containing polymer was then removed, as taught by Wyse, using the oxygen-based chemistry.
One of ordinary skill in the art would have been motivated to make this modification because it would have allowed for the removal of the non-volatile products created from the hydrogen and hydrocarbon process gas with the oxygen-containing gas, as taught by Wyse (Paragraph [0034] “second chamber clean chemistry reacts with the first non-volatile products to form more volatile products that can be more easily removed from the chamber”). Additionally, this modification would have been obvious because it would have been the combination of prior art elements according to known methods to yield predictable results. Yu teaches the use of oxygen-based chemistry to remove a carbon-containing material, and the combination would have had the predictable result of removing the carbon-containing polymer.
Regarding Claim 20, modified Yu teaches all the limitations of claim 19 as outlined above. Yu teaches that the method further comprises:
applying photoresist to the semiconductor substrate prior to (b) (Paragraph [0098] a blanket layer of photoresist may be deposited over the tin oxide);
exposing the photoresist to light (Paragraph [0098] the photoresist “may be patterned using photolithographic techniques.” Paragraph [0101] patterning photoresists include exposing the photoresist to light);
patterning the photoresist and transferring the pattern to the semiconductor substrate, wherein transferring the pattern to the semiconductor substrate is performed prior to (b), or wherein transferring the pattern to the semiconductor substrate comprises etching the tin oxide layer by exposing the semiconductor substrate to the process gas comprising the hydrocarbon and hydrogen in (b) (Paragraph [0098] where there may be intermediate layers between the photoresist and the tin oxide layer such that the pattern of the photoresist is first transferred to the intermediate layers. Or if the pattern is transferred from the photoresist directly to the tin oxide layer then the process used for step (b) as outlined above in regards to claim 19 is used);
and selectively removing the photoresist from the semiconductor substrate (Paragraph [0099] an oxygen-based chemistry is used to etch a carbon layer that simultaneously removes the photoresist).
Regarding Claims 21 and 22, modified Yu teaches all the limitations of claim 19 as outlined above. Yu teaches that the method further comprises prior to (a), depositing the layer of tin oxide using a tin-containing precursor consisting of tetrakis(dimethylamino) tin (Paragraph [0098] prior to the method outlined above in regards to claim 19, the tin oxide layer can be deposited. Paragraph [0081] methods for depositing a tin oxide layer are provided that include the use of the tin-containing precursor tetrakis(dimethylamino) tin), thereby meeting the limitations of both claims 21 and 22.
Claims 12 and 24 are rejected under 35 U.S.C. 103 as being unpatentable over Wyse in view of Yu as applied to claim 1 above, and further in view of Luere et al. (US-20150287612-A1).
Regarding Claims 12 and 24, modified Wyse teaches all the limitations of claim 1 as outlined above.
Modified Wyse fails to teach wherein (c) comprises exposing the carbon-containing polymer to a process gas consisting essentially of H2 or consisting essentially of a mixture of H2 and an inert gas in a plasma, as required by claim 12 and fails to teach wherein (c) comprises exposing the carbon-containing polymer to H2, wherein exposure to H2 is performed in the absence of hydrocarbon.
Luere teaches a method of etching (Paragraph [0020]). Luere teaches a method of etching a carbon-containing layer with a process gas that is hydrogen (Paragraph [0021] etching a carbon-containing layer using precursors exited by plasma where the precursors can be hydrogen, H2).
It would have been obvious to one of ordinary skill in the art to have altered the method of modified Wyse as outlined above in regards to claim 1 such that the removal of the carbon-containing polymer used the etching process taught by Luere. With this modification the limitations of claims 12 and 24 would be met as H2 would be exposed to the carbon-containing polymer in the absence of hydrocarbon and the process gas would consist essentially of H2 or consist essentially of a mixture of H2 and an inert gas in a plasma.
This modification would have been obvious as it would have been the simple substitution of one known element for another to obtain predictable results. The etching process taught by Luere is used to remove a carbon-containing material and in the combination would have had the predictable result of removing the carbon-containing polymer. See MPEP 2143(I)(B).
Claim 25 is rejected under 35 U.S.C. 103 as being unpatentable over Wyse in view of Yu as applied to claim 1 above, and further in view of Ni et al. (CN-101800174-A, machine translation).
Modified Wyse teaches all the limitations of claim 1 as outlined above.
Modified Wyse fails to teach wherein (c) comprises exposing the carbon-containing polymer to the oxygen-containing reactant and exposing the carbon-containing polymer to H2 in the absence of hydrocarbon.
Ni teaches a method of etching a carbon-containing layer (Paragraph [0002]). Ni teaches that etching the carbon-containing layer uses an etching gas that include an oxygen-containing gas and a hydrogen-containing gas that can be H2 (Paragraphs [0014-0016]).
It would have been obvious to one of ordinary skill in the art to have modified the method of modified Wyse by using the etching process and etching gas taught by Ni. With this modification the instant limitations would be met.
This modification would have been obvious as it would have been the simple substitution of one known element for another to obtain predictable results. The etching process taught by Ni is used to remove a carbon-containing material and in the combination would have had the predictable result of removing the carbon-containing polymer. See MPEP 2143(I)(B).
Claim 26 is rejected under 35 U.S.C. 103 as being unpatentable over Wyse in view of Yu as applied to claim 1 above, and further in view of Hsu et al. (US-20150371864-A1).
Modified Wyse teaches all the limitations of claim 1 as outlined above.
Modified Wyse fails to teach wherein the temperature in (a), (b), and (c) is substantially constant. However, Yu teaches that step (b) can be conducted at a temperature of less than 100°C (Paragraph [0049] conversion of tin oxide to a volatile tin hydride can be conducted at temperatures lower than 100°C).
It would have been obvious to one of ordinary skill in the art to have modified the method of modified Wyse by conducting step (b) at a temperature lower than 100°C as taught by Yu.
This modification would have been obvious as it would have been the combination of prior art elements according to known methods to yield predictable results. This combination would have provided the predictable result of providing a suitable temperature for the process step of converting tin oxide to tin hydride. See MPEP 2143(I)(A).
As outlined above, modified Wyse is silent on the temperature during (a) providing a process chamber having a layer of tin oxide on at least some parts of the process chamber. However, in the moment immediately prior to (b) when the tin oxide layer is exposed to the process gas, a temperature of the process chamber would need to be a temperature suitable for the method step (b) to take place. Therefore, one can consider (a) providing the process chamber, to occur in that moment immediately prior to the start of (b), such that a temperature in (a) would be substantially constant with a temperature in (b).
Modified Wyse, as outlined above, fails to teach that a temperature during (c) is substantially constant compared to a temperature in (a) and (b). Yu, which is relied upon for the teaching of the removing the carbon-containing polymer with an oxygen-containing reactant, is silent on a temperature during this method step.
Hsu teaches a method of etching carbon films using a plasma etching process that uses oxygen-containing gases (Paragraph [0004]). Hsu teaches that during the etching process of removing the carbon-containing material the temperature can be between about -20 and 140°C (Paragraph [0025]).
It would have been obvious to one of ordinary skill in the art to have modified the method of modified Wyse by using as a temperature for (c) a temperature within the range taught by Hsu.
This modification would have been obvious as it would have been the combination of prior art elements according to known methods to yield predictable results. This combination would have provided the predictable result of providing a suitable temperature for the process step of removing a carbon-containing material using an oxygen-containing reactant. See MPEP 2143(I)(A).
Where modified Wyse, as outlined above, teaches a temperature for (a) and (b) to be less than 100°C and Hsu teaches a temperature for (c) to be between about -20 and 140°C, it would have been obvious to one of ordinary skill in the art to have selected a temperature for (a), (b), and (c) to be substantially constant.
This selection would have been obvious because using the same temperature for (a), (b), and (c) would reduce the amount of energy required by the process for heating or cooling that may be required if different temperatures were selected. Additionally, the ranges taught by the cited references are similar, with many overlapping values for a temperature that would be suitable for each method step. Selection from the taught ranges, that would result in values that overlap with the claimed limitation can be considered obvious.
Response to Arguments
Applicant’s arguments, see Remarks Pg. 1-2, filed 09/02/2025, with respect to the 35 U.S.C. § 103 rejection have been fully considered and are not persuasive.
Applicant argues that the prior art fails to teach a molar ratio of hydrogen (H2) to the hydrocarbon that is between 1:15 and 1:25.
Examiner respectfully disagrees. As outlined in the rejection of claims 1 and 19 above, the prior art does teach embodiments where the molar ratio of hydrogen to hydrocarbon overlaps with the claimed range.
Applicant argues that the prior art fails to teach using H2 in the absence of a hydrocarbon to remove a carbon-containing material.
Examiner respectfully disagrees. As outlined in the rejection of claims 12 and 14, the prior art does teach this claimed limitation.
Conclusion
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/A.K.L./Examiner, Art Unit 1713
/JOSHUA L ALLEN/Supervisory Patent Examiner, Art Unit 1713