DETAILED ACTION
Claims 1-21 and 26 are pending before the Office for review.
In the response filed May 19, 2026:
Claims 1, 4, 5, 7.12, 14 and 16 were amended.
Claims 22-25 were canceled.
Claim 26 is 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 Interpretation
The transitional phrase "consisting essentially of" limits the scope of a claim to the specified materials or steps "and those that do not materially affect the basic and novel characteristic(s)" of the claimed invention. In re Herz, 537 F.2d 549, 551-52, 190 USPQ 461, 463 (CCPA 1976) (emphasis in original) For the purposes of searching for and applying prior art under 35 U.S.C. 102 and 103, absent a clear indication in the specification or claims of what the basic and novel characteristics actually are, "consisting essentially of" will be construed as equivalent to "comprising." See, e.g., PPG, 156 F.3d at 1355, 48 USPQ2d at 1355 ("PPG could have defined the scope of the phrase ‘consisting essentially of’ for purposes of its patent by making clear in its specification what it regarded as constituting a material change in the basic and novel characteristics of the invention."). MPEP 2111.03(III) It is the Examiner’s position that Applicant has not demonstrated by clear indication in the specification or claims of what the basic and novel characteristics actually are, "consisting essentially of" will be construed as equivalent to "comprising." In addition, is the Examiner’s opinion that the additional component would not materially change the characteristics of the claimed invention.
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 1-2, 4-9, 12-13, 20 and 26 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 consisting essentially of at least one fluorine-containing component, chlorine gas, optionally SiCl4, optionally an oxygen containing component and optionally an inert gas component. (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 SiCl4 is present in the etchant gas mixture. (Paragraphs [0021], [0036], claim 4)
With regards to claims 5-6, the modified teachings of Leverich renders obvious wherein the oxygen-containing component is present in the etchant gas mixture; 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 inert gas component is present in the etchant gas mixture 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)
With regards to claim 26, the modified teachings of Leverich renders obvious an etchant gas comprising a chloring bearing etchant and a fluorine bearing gas wherein the combination of gases an provide for an increase in nearly perfect vertical etch of silicon; with reduced undercutting wherein the F/C ratio is adjust to prevent undercutting (Paragraphs [0032]-[0038]) wherein the flow rate of the halogen bearing gas, chloride gas and fluoride gas base don the advantage of anisotropic etch (Paragraphs [0039]-[0040]) rendering obvious altering a ratio of the at least one fluorine-containing component and the chlorine gas and/or the SiCl4 in a flow of the etchant gas mixture thereby changing a profile angle of the feature.
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, 20 and 26, 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
Response to Arguments
Applicant's arguments filed May 19, 2026 have been fully considered but they are not persuasive.
Applicant argues on pages 6-8 of Applicant’s response that the cited prior art fails to teach or render obvious Applicant’s claimed invention. Applicant argues that the cited prior art fails to teach or render obvious “… performing a plasma etch step to anisotropically etch the substrate through the opening to produce a feature, wherein the °°consisting essentially of at least one fluorine-containing component, a chlorine gas, optionally SiCl4, optionally an oxygen-containing component, and optionally an inert gas component.” In particular, Applicant argues that Leverich requires the inclusion of “dibromoethane” materially affects the characteristics of the etching because it affects the resulting angle of eth etch process recited in claim 1. Applicant’s claim 1, the flow rate of the recited components in the etchant gas mixture changes the profile angle of the feature. It is Applicant’s position that adding dibromoethane will change the effects of the recited etchant gas mixture. The dependent claims are allowable based on their dependency. This is found unpersuasive.
It is the Examiner’s position that cited prior art renders obvious Applicant’s claimed invention. In particular the Examiner argues that the inclusion of the dibromoethane will not materially affect the characteristics of etching of Applicant’s claimed invention. Applicant’s specification page 10 line 20 – page 11 line 2 indicates the sidewalls have a based that is approximately parallel to the surface of the substrate and the sidewalls have a taper between about 87 and 90° to the plane perpendicular to the direction of anisotropic etching. Leverich further discloses wherein the addition of the dibromoethane forms increase etch rates and nearly perfect vertical etch (substantially undercutting) (Paragraph [0035]) which would not affect Applicant’s 90° perpendicular plane.
The transitional phrase "consisting essentially of" limits the scope of a claim to the specified materials or steps "and those that do not materially affect the basic and novel characteristic(s)" of the claimed invention. In re Herz, 537 F.2d 549, 551-52, 190 USPQ 461, 463 (CCPA 1976) (emphasis in original) For the purposes of searching for and applying prior art under 35 U.S.C. 102 and 103, absent a clear indication in the specification or claims of what the basic and novel characteristics actually are, "consisting essentially of" will be construed as equivalent to "comprising." See, e.g., PPG, 156 F.3d at 1355, 48 USPQ2d at 1355 ("PPG could have defined the scope of the phrase ‘consisting essentially of’ for purposes of its patent by making clear in its specification what it regarded as constituting a material change in the basic and novel characteristics of the invention."). MPEP 2111.03(III) Applicant’s currently presented amend claim does not claim a method in which introduction of the dibromoethane would substantially change the characteristics of the claimed invention such that it would affect any novel characteristics including a tapered wall. As such the Examiner maintains that “consisting essentially” is interpreted as “comprising” for the purpose of examination. The Examiner maintains the rejection of record. As to the dependent claims they remain rejected as no separate arguments have been provided.
Conclusion
THIS ACTION IS MADE FINAL. Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
A shortened statutory period for reply to this final action is set to expire THREE MONTHS from the mailing date of this action. In the event a first reply is filed within TWO MONTHS of the mailing date of this final action and the advisory action is not mailed until after the end of the THREE-MONTH shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any nonprovisional extension fee (37 CFR 1.17(a)) pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than SIX MONTHS from the mailing date of this final action.
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
