DETAILED ACTION
Claims 1-25 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 .
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
Election/Restrictions
Applicant’s election without traverse of Group I (claims 1-21) in the reply filed on September 2, 2026 is acknowledged.
Claims 22-25 are withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim. Election was made without traverse in the reply filed on September 2, 2026.
Claim Objections
Claim 7 is objected to because of the following informalities: Claim 7 should be amended to recite “fluorine-containing component” rather than ““fluorine containing component” in order to be consistent with claim 1. Appropriate correction is required.
Claim 14 is objected to because of the following informalities: Claim 14 should be amended to recite “wherein a flow rate of the inert gas” for antecedent purposes. Claim 12 does not reference flow rate. Appropriate correction is required.
Claim 16 is objected to because of the following informalities: Claim 16 should be amended to recite “The method according to claim 1” rather than ““A method according to claim 1” in order to be consistent with claim 1. Appropriate correction is required.
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 1-2, 4-9, 12-13 and 20 are rejected under 35 U.S.C. 103 as being unpatentable over LEVERICH (U.S. Patent Application Publication 2005/0029226).
With regards to claim 1, Leverich discloses a method of plasma etching a silicon containing semiconductor substrate to form a feature, the method comprising the steps of. providing a substrate (1) with a mask (2) formed thereon on a substrate support in a chamber, the mask (1) having an opening; and performing a plasma etch step to anisotropically etch the substrate through the opening to produce a feature wherein the plasma etch step comprises generating a plasma from an etchant gas mixture comprising at least one fluorine-containing component and chlorine gas. (Paragraphs [0013], [0018]-[0019], [0034]-[0038] Figure 1),
Leverich does not explicitly disclose wherein the substrate is formed from silicon carbide.
However Leverich discloses wherein the etch process taught by an embodiments of the present invention is applicable not only to single crystalline silicon or polysilicon but is also applicable to other composition which contain large silicon content for example silicon carbide (Paragraph [0038]) rendering obvious wherein the substrate is formed from silicon carbide.
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 Leverich to include the silicon carbide of the general disclosure of Leverich because the reference of Leverich teaches that the etch process is applicable to silicon materials including silicon carbide (Paragraph [0038]) 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 plasma etching using the silicon carbide material as rendered obvious by Leverich. MPEP 2143D
With regards to claim 2, the modified teachings of Leverich renders obvious wherein the at least one fluorine-containing component comprises SF6 (Paragraph [0036], claim 8).
With regards to claim 4, the modified teachings of Leverich renders obvious wherein the etchant gas mixture further comprises SiCl4. (Paragraphs [0021], [0036], claim 4)
With regards to claims 5-6, the modified teachings of Leverich renders obvious wherein the etchant gas mixture further comprises an oxygen-containing component; wherein the oxygen-containing component is O2 gas. (Paragraph [0037], claim 18).
With regards to claim 7, the modified teachings of Leverich renders obvious wherein the flow rate of the at least one fluorine containing component (halogen bearing gas) is 1-1000 sccm and the flow rate of the chlorine gas 0-30 times the flow rate of the fluorine gas (Paragraph [0038]) which renders obvious wherein a flow rate of each of the at least one fluorine containing component and chlorine gas is at most 100 sccm. 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 8, the modified teachings of Leverich renders obvious a fluorine containing gas wherein the fluorine containing gas comprises sulfur hexafluoride (Paragraph [0036], Claim 8) wherein the flow rate of the at least one fluorine containing component (halogen bearing gas) is 1-1000 sccm (Paragraph [0038]) which renders obvious wherein a flow rate of SF6 is from 30 sccm to 60 sccm. 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 9, the modified teachings of Leverich renders obvious wherein the flow rate the flow rate of the chlorine gas 0-30 times the flow rate of the halogen bearing gas wherein the flow rate of the halogen bearing gas is from 1 to 1000 sccm (Paragraph [0038]) renders obvious wherein a flow rate of SiCl4 is from 5 sccm to 95 sccm. 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 12-13, the modified teachings of Leverich renders obvious wherein the etchant gas mixture further comprises an inert gas component and wherein the inert gas component is argon. (Paragraph [0037])
With regards to claim 20, the modified teachings of Leverich renders obvious wherein a pressure within the chamber is from 0.005 Torr to about 5 Torr (Paragraph [0039]) which overlaps Applicant’s claimed amount of 2 mTorr (0.267 Pa) to 20 mTorr (2.67 Pa). 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)
Claims 3, 10-11, 14-19, and 21 are rejected under 35 U.S.C. 103 as being unpatentable over LEVERICH (U.S. Patent Application Publication 2005/0029226), as applied to claims 1-2, 4-9, 12-13 and 20, in view of OKUNE et al (JP2017-112293 as evidenced by the machine translation).
With regards to claim 3, the modified teachings of Leverich renders obvious the limitations of claim 2 including wherein the at least one fluorine containing component comprises SF6 (Paragraph [0036], claim 8).
The modified teachings of Leverich are silent as to wherein the at least one fluorine containing component comprise SiF4.
Okune discloses a method of plasma etching a silicon carbide semiconductor substrate comprising using at least one fluorine containing component comprising both SF6 and SiF4 (Paragraphs [0028]-[0032]).
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 further modify the modified teachings of Leverich to include the at least one fluorine containing component comprising both SF6 and SiF4 as rendered obvious by Okune because the reference of Okune teaches that this combination results in a SiC substrate etched at a desired depth and groove shape (Paragraph [0029], [0031]) 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 plasma etching using both SF6 and SiF4 as rendered obvious by Okune. MPEP 2143D
With regards to claims 10-11, the modified teachings of Leverich renders obvious the limitations of claim 5 as previously discussed.
However the modified teachings of Leverich are silent as to wherein a flow rate of the oxygen- containing component is from 5 sccm to 95 sccm, 50 sccm to 80 sccm.
Okune discloses a method of plasma etching a silicon carbide semiconductor substrate comprising using at least one fluorine containing component comprising both SF6 , SiF4 and oxygen (Paragraphs [0028]-[0032]) wherein the oxygen is in a volume ration sufficient to adjust the etching of the groove and shape the bottom groove such as more easily rounding (Paragraphs [0032]). Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955) MPEP 2144.05 (II)(A) Okune discloses wherein the flow rate of oxygen is amounts such as 23sccm (Paragraph [0052]) which renders obvious wherein a flow rate of the oxygen- containing component is from 5 sccm to 95 sccm. 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) 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 optimize the concentration of oxygen to amounts including Applicant’s claimed amount of from about 50 sccm to 80 sccm in order adjust the etching of the groove and shape the bottom groove for easily rounding as taught by the modified teachings of Leverich in view of Okune (Paragraph [0032], MPEP 2144.05(II)(A)).
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 further modify the modified teachings of Leverich to include the flow rate of oxygen as rendered obvious by Okune because the reference of Okune teaches the flow rate of oxygen can adjust the etching of the groove and shape the bottom groove such as more easily rounding (Paragraphs [0032]). 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 plasma etching using oxygen flow rate as rendered obvious by Okune. MPEP 2143D
With regards to claims 14-15, the modified teachings of Leverich renders obvious the limitations of claim 12 as previously discussed.
However the modified teachings of Leverich are silent as to wherein the flow rate of the inert gas component is at most 500 sccm and at least 300 sccm.
Okune discloses a method of plasma etching a silicon carbide semiconductor substrate comprising using at least one fluorine containing component comprising both SF6 , SiF4, oxygen and an inert gas (Paragraphs [0028]-[0032]) wherein the inert gas of argon may be present in amounts including 500 sccm (Paragraph [0052]) which renders obvious wherein the flow rate of the inert gas component is at most 500 sccm and at least 300 sccm. 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)
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 further modify the modified teachings of Leverich to include the flow rate of the inert as rendered obvious by Okune 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 plasma etching using inert gas flow rate as rendered obvious by Okune. MPEP 2143D
With regards to claim 16, the modified teachings of Leverich renders obvious the limitations of claim 1 as previously discussed.
However the modified teachings of Leverich are silent as to wherein the plasma etch step is performed using a plasma source that supplies a power of from 800 W to 2500 W to the plasma.
Okune discloses a method of plasma etching a silicon carbide semiconductor substrate comprising using at least one fluorine containing component comprising both SF6 , SiF4, oxygen and an inert gas (Paragraphs [0028]-[0032]) wherein the plasma etch step is performed using a plasma source that supplies a power of from 300W -4000W (Paragraph [0034]) which renders obvious 800 W to 2500 W to the plasma. 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)
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 further modify the modified teachings of Leverich to include the plasma power as rendered obvious by Okune 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 plasma etching using the power as rendered obvious by Okune. MPEP 2143D
With regards to claim 17, the modified teachings of Leverich renders obvious the limitations of claim 1 as previously discussed.
However the modified teachings of Leverich are silent as to wherein an electrical power of from 700 W to 1400 W is applied to the substrate support during the plasma etch step.
Okune discloses a method of plasma etching a silicon carbide semiconductor substrate comprising using at least one fluorine containing component comprising both SF6 , SiF4, oxygen and an inert gas (Paragraphs [0028]-[0032]) wherein the plasma etch step is performed using a power applied to the SiC substrate in an amount of produce a power density that allows desired shaped bottom of the groove while ensuring a high etching rate (Paragraph [0035]). Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955) MPEP 2144.05 (II)(A) Therefore 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 optimize the electrical power applied to the substrate support during the plasma etch step to amounts including Applicant’s claimed amount of from 700W to 1400 W in order to produce a power density that allows desired shaped bottom of the groove while ensuring a high etching rate as taught by the modified teachings of Leverich in view of Okune (Paragraph [0035], MPEP 2144.05(II)(A)).
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 further modify the modified teachings of Leverich to include the electrical power as rendered obvious by Okune because the reference of Okune teaches that such power produces a power density that allows desired shaped bottom of the groove while ensuring a high etching (Paragraph [0035]) 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 plasma etching using the electrical power as rendered obvious by Okune. MPEP 2143D
With regards to claims 18-19 and 21, the modified teachings of Leverich renders obvious the limitations of claim 1 as previously discussed.
However the modified teachings of Leverich are silent as to wherein the substrate support is maintained at a temperature of between 10°C and 30 °C; wherein the temperature is about 20 °C and wherein the chamber is cooled to a temperature of 55 °C.
Okune discloses a method of plasma etching a silicon carbide semiconductor substrate comprising using at least one fluorine containing component comprising both SF6 , SiF4, oxygen and an inert gas (Paragraphs [0028]-[0032]) wherein the plasma etch step is performed wherein the etching is performed a temperature of 150°C or less wherein the etching is at a temperature is set at to an amount which allows for the bottom groove etching and rounding (Paragraph [0036]) which renders obvious wherein the chamber is cooled to a temperature of 55 °C. In addition, 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 optimize the temperature to amounts including Applicant’s claimed amount of between 10°C and 30°C or 20°C in order to easily etch the bottom of the groove as taught by the modified teachings of Leverich in view of Okune (Paragraph [0036], MPEP 2144.05(II)(A)). Generally, differences in concentration or temperature will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such concentration or temperature is critical. "[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955) MPEP 2144.05(II)(A)
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 further modify the modified teachings of Leverich to include the temperature as rendered obvious by Okune 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 plasma etching using the temperature as rendered obvious by Okune. MPEP 2143D
Conclusion
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/STEPHANIE P DUCLAIR/Primary Examiner, Art Unit 1713