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 .
Status of the Claims
This is a final office action in response to the applicant’s arguments and remarks filed on 10/02/2025. Claims 1-4, 6-26, and 28-35 are pending in the current office action. Claims 1, 9, 24 have been amended by the applicant. Claims 5 and 27-31 were cancelled. Claims 32-35 remain withdrawn (examiner notes that claims 32-35 were mistakenly labeled as claims 28-31 in the set of claims filed on 10-02/2025).
Status of the Rejection
The drawing and Claim objections have been overcome by the applicant's amendments.
All 35 U.S.C. § 112(b) rejections from the previous office action are withdrawn in view of the Applicant’s amendment.
The rejection of claims 5 and 27-31 are obviated by the Applicant’s cancellation.
All 35 U.S.C. § 103 rejections from the previous office action are withdrawn in view of the applicant’s amendment.
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 1-4, 6-10, and 14-26 are rejected under 35 U.S.C. 103 as being unpatentable over Blomberg et al. (US-20180182597-A1).
Regarding Claim 1, Blomberg teaches a method (Paragraph [0002] etching processes taught), comprising:
providing a substrate to a processing chamber, the substrate having a semiconductor portion and another portion (Paragraph [0143] Providing a substrate with a material to be etched and may comprise material other than the etching target. Paragraph [0144] material to be etched can be Si or Ge which are semiconductors);
modifying the semiconductor portion of the substrate selective to the other portion of the substrate by flowing a first process gas comprising a first halogen species onto the substrate and providing a first activation energy to cause the first halogen species to preferentially adsorb on the semiconductor portion relative to the other portion to form a first halogenated semiconductor (Paragraph [0060] first reactant adsorbs to the material to be etched. Paragraphs [0061-0065] multiple example first reactants are taught that comprise a halogen. Paragraph [0143] etch process is selective to material to be etched relative to other materials on the substrate. Paragraph [0068] methods are thermal etching processes, where thermal energy can provide any activation energy required. Paragraph [0141] cycles are conducted with a temperature provided, thereby providing the claimed "first activation energy" Paragraph [0006] the first reactant formed a reactant species on the substrate surface); and
removing the first halogenated semiconductor by flowing a second process gas comprising a second halogen species onto the substrate and providing a second activation energy, without providing a plasma, to cause the second halogen species to react with the first halogenated semiconductor and cause the first halogenated semiconductor to desorb from the substrate (Paragraph [0006] the reactant species formed by the first reactant reacts with the second reactant to form a volatile species that is then removed from the substrate. Paragraph [0005] second reactant is a halide ligand, therefore contains a halogen. Paragraph [0068] methods are thermal etching processes, where thermal energy can provide any activation energy required and no plasma is used. Paragraph [0141] cycles are conducted with a temperature provided, thereby providing the claimed "second activation energy"),
wherein the semiconductor portion comprises one or more of silicon, germanium, silicon-germanium, or a doped silicon (Paragraph [0144] material to be etched can be Si or Ge).
Blomberg fails to explicitly teach that the other portion of the substrate is a dielectric portion.
However, Blomberg does teach that the substrate can comprise dielectric materials (Paragraphs [0143-0144] multiple examples of dielectric materials, such as silicon oxide). Blomberg also provides example embodiments where silicon oxide is not etched (Paragraphs [0161-0162] Figure 6 no etching silicon oxide films or native oxide was observed in the example embodiments).
It would have been obvious to one of ordinary skill in the art to have modified the method of Blomberg such that the during the selective etching of a semiconductor material, the material on the substrate that is not etched is silicon oxide.
This modification would have been obvious because Blomberg teaches a selective etching process, teaches semiconductor materials as suitable etching target materials, teaches that the substrate could comprise silicon oxide, and teaches embodiments that do not etch silicon oxide. One of ordinary skill in the art could have reasonably selected a substrate that comprised silicon oxide, where the silicon oxide was not the target material of the selective etching process. Alternatively, this modification could be considered to have been the simple substitution of one unspecified substrate material not-to-be-etched with another. The simple substitution of one known element for another is likely to be obvious when predictable results are achieved. See MPEP §2143(B). Furthermore, the selection of a known material, which is based upon its suitability for the intended use, is within the ambit of one of ordinary skill in the art. See MPEP § 2144.07.
Regarding Claim 2, Blomberg further teaches wherein during the removing: the second halogen species reacts with the first halogenated semiconductor to convert the first halogenated semiconductor to a second halogenated semiconductor, and the desorption of the first halogenated semiconductor includes desorption of the second halogenated semiconductor (Paragraph [0006] the reactant species formed by the first reactant reacts with the second reactant to form a volatile species that is then removed from the substrate).
Regarding Claim 3, Blomberg further teaches wherein the second halogenated semiconductor is more volatile than the first halogenated semiconductor (Paragraph [0060] first reactant adsorbs to the material to be etched while the second reactant results in the formation of volatile by-products, therefore the product formed by the second reactant, equivalent to the claimed second halogenated semiconductor, is more volatile than the product formed when the first reactant adsorbs).
Regarding Claim 4, modified Blomberg fails to explicitly teach wherein: the first halogen species comprises chlorine, the first halogenated semiconductor comprises silicon tetrachloride (SiCI4), the second halogen species comprises fluorine, and the second halogenated semiconductor comprises silicon tetrafluoride (SiF4).
However, Blomberg teaches that the first reactant can be a chlorinating agent and the second reactant can be a fluorinating agent (Paragraph [0022]). Blomberg teaches that the semiconductor portion to be etched can be silicon (Paragraph [0144]).
Examiner takes the position that it would have been obvious in an embodiment where the material to be etched is silicon and the first reactant is a chlorinating agent and the second reactant is a fluorinating agent, that the resulting material (equivalent to the claimed first halogenated semiconductor) formed when the first reactant adsorbs to the silicon of the would be silicon tetrachloride, and that the resulting material (equivalent to the claimed second halogenated semiconductor) that formed when the second reactant reacted with the modified silicon would be silicon tetrafluoride.
This would have been obvious as there are a finite number of identified and predictable potential from the chlorination and fluorination of a silicon material. See MPEP 2143(I)(E).
Regarding Claim 6, modified Blomberg teaches wherein the dielectric portion comprises one or more of an oxide or a nitride (as outlined above in regards to the rejection of Claim 1, the dielectric portion comprises silicon oxide).
Regarding Claim 7, Blomberg further teaches wherein, at the first activation energy, the semiconductor portion is halogenated by the first halogen species without halogenating the dielectric portion (Paragraph [0060] first reactant adsorbs to the material to be etched. Paragraph [0143] etch process is selective to material to be etched relative to other materials on the substrate).
Regarding Claim 8, Blomberg further teaches wherein, at the second activation energy, the first halogenated semiconductor is removed by a reaction with the second halogen species without removing the dielectric portion (Paragraph [0143] etch process is selective to material to be etched relative to other materials on the substrate. Paragraph [0148] no substantial amount of material is removed from the non-desired material).
Regarding Claim 9, Blomberg further teaches providing the first activation energy is provided by heating the substrate to a first temperature (Paragraph [0068] the etching method is a thermal etching process, where heat is provided for the activation energies required in the process. Paragraph [0141] the etching process is performed at certain temperatures. Paragraph [0162] in an example the temperature provided is described as setting the substrate to a certain temperature).
Regarding Claim 10, Blomberg further teaches wherein the first temperature is greater than about 100 °C (Paragraph [0141] the method is conducted at certain temperatures “In some embodiments, the temperature is greater than about … 100°C”).
Regarding Claim 14, Blomberg further teaches wherein the second activation energy is provided, without using a plasma, by heating the substrate to a temperature. (Paragraph [0068] the etching method is a thermal etching process, where heat is provided for the activation energies required in the process and plasma is not used. Paragraph [0141] the etching process is performed at certain temperatures. Paragraph [0162] in an example the temperature provided is described as setting the substrate to a certain temperature).
Regarding Claim 15, Blomberg further teaches wherein the temperature is greater than or equal to about 100 °C (Paragraph [0141] the method is conducted at certain temperatures “In some embodiments, the temperature is greater than about … 100°C”).
Regarding Claim 16, Blomberg fails to teach wherein the modifying is performed while the substrate is maintained at a temperature less than or equal to about 150 °C.
However, Blomberg teaches that the method is conducted at certain temperatures that can range from about 20°C to about 1200°C (Paragraph [0068] the etching method is a thermal etching process, where heat is provided for the activation energies required in the process. Paragraph [0141] the etching process is performed at certain temperatures. Paragraph [0162] in an example the temperature provided is described as setting the substrate to a certain temperature).
It would have been obvious to one of ordinary skill in the art to have selected and incorporated a temperature at a level within the disclosed range of about 20°C to about 1200°C, including at amounts that overlap with the claimed range of less than or equal to about 150 °C. 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).
Regarding Claim 17, Blomberg further teaches wherein the removing is performed while the substrate is maintained at a temperature greater than or equal to about 100 °C (Paragraph [0068] the etching method is a thermal etching process, where heat is provided for the activation energies required in the process. Paragraph [0141] the etching process is performed at certain temperatures including “In some embodiments, the temperature is greater than about … 100°C”. Paragraph [0162] in an example the temperature provided is described as setting the substrate to a certain temperature).
Regarding Claim 18, Blomberg further teaches wherein the first and second halogen species each comprise a different halogen species selected from the group consisting of fluorine, chlorine, bromine, and iodine (Paragraph [0022] the first reactant can be a chlorinating agent and the second reactant can be a fluorinating agent).
Regarding Claim 19, Blomberg further teaches wherein: the first halogen species comprises chlorine, and the second halogen species comprises fluorine (Paragraph [0022] the first reactant can be a chlorinating agent and the second reactant can be a fluorinating agent).
Regarding Claim 20, Blomberg further teaches wherein: the first halogen species comprises fluorine, and the second halogen species comprises chlorine (Paragraph [0022] the first reactant can be a fluorinating agent and the second reactant can be a chlorinating agent).
Regarding Claim 21, Blomberg further teaches wherein: the first process gas comprises chlorine (Cl2), and the second process gas comprises hydrogen fluoride (HF) (Paragraphs [0101-0102] Halide reactants can be SeO2Cl2, SO2Cl2, SeOCl2, or NCl2F which all comprise Cl2. Paragraph [0097] halide reactant can be NX, where N is hydrogen and X is fluorine).
Regarding Claim 22, Blomberg further teaches wherein the semiconductor portion comprises silicon (Paragraph [0144] material to be etched can be Si).
Regarding Claim 23, modified Blomberg teaches wherein the dielectric portion comprises a silicon oxide or a silicon nitride (as outlined above in regards to the rejection of Claim 1, the dielectric portion comprises silicon oxide).
Regarding Claim 24, Blomberg further teaches wherein the modifying of the semiconductor portion and/or the removing of the first halogenated semiconductor occurs isotropically (Paragraph [0068] the thermal ALE method can be an isotropic etching process).
Regarding Claim 25, Blomberg further teaches wherein the semiconductor portion does not comprise a silicon oxide (Paragraph [0144] material to be etched can be Ge, which would not comprise silicon oxide).
Regarding Claim 26, Blomberg further teaches that the method further comprises flowing, before or during the removing, a catalyst onto the substrate, wherein the catalyst is configured to assist with the reaction between the second halogen species and the first halogenated semiconductor (Paragraph [0078] additional reactant can be provided to improve or tune selective etching, can be provided with the second halide. This additional reactant can be considered the claimed catalyst).
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Blomberg as applied to claims 1 and 2 above, and further in view of Nishino et al. (US-5030319-A, IDS Document) and Woo et al. (US-20180114700-A1).
Regarding Claim 4, (Note: claim 4 was rejected above with one interpretation of obviousness and is being rejected here with an alternative interpretation in view of the prior art cited in this section) modified Blomberg teaches all the limitations of claims 1 and 2 as outlined above.
Blomberg further teaches that the first reactant can be a chlorinating agent and the second reactant can be a fluorinating agent (Paragraph [0022]). Blomberg also teaches that the semiconductor portion to be etched can be silicon (Paragraph [0144]).
Modified Blomberg fails to teach that the first halogenated semiconductor comprises silicon tetrachloride (SiCI4) and the second halogenated semiconductor comprises silicon tetrafluoride (SiF4).
Nishino teaches a method of etching (Column 1 lines 7-11). Nishino teaches when silicon atoms are etched with a chlorine gas, silicon tetrachloride can be produced (Column 1 lines 50-56).
Woo teaches a method of atomic layer etching (Paragraph [0002]). Woo teaches that in the etching process silicon atoms can combine with fluorine-containing etching gases to form silicon tetrafluoride (Paragraph [0026]).
It would have been obvious to one of ordinary skill in the art to have modified the method of modified Blomberg, such that in an embodiment of the method of modified Blomberg where silicon is being etched and the first reactant is a chlorinating agent and the second reactant is a fluorinating agent, then a result of the first reactant adsorbing to the silicon portion is the formation of silicon tetrachloride, as taught by Nishino, and a result of the second reactant etching the modified silicon surface is the formation of silicon tetrafluoride, as taught by Woo.
This modification would have been obvious as it can be considered the combination of prior art elements according to known methods to yield predictable results. The prior art, in Nishino and Woo, teach that silicon tetrachloride and silicon tetrafluoride are possible reaction products formed in the process of etching silicon atoms and this combination would have had the predictable result of forming those molecules in the process of etching silicon. See MPEP 2143(I)(A).
Claims 11-13 are rejected under 35 U.S.C. 103 as being unpatentable over Blomberg in view of Anthis (US-20180342403-A1).
Regarding Claims 11 and 12, modified Blomberg teaches all the limitations of claims 1 and 9. However Blomberg fails to teach wherein: the first activation energy is provided by heating the substrate and by a plasma, and the first temperature is less than or equal to about 250 °C, as required by Claim 11, or where the first temperature is less than or equal to about 150°C, as required by Claim 12.
However, Blomberg teaches that the method is conducted at certain temperatures that can range from about 20°C to about 1200°C and that the temperature is greater than about 100°C (Paragraph [0141]).
It would have been obvious to one of ordinary skill in the art to have selected and incorporated a temperature for conducting the method, including the step of providing a first activation energy, at a level within the disclosed range of greater than about 100°C to about 1200°C, including at amounts that overlap with the claimed range of greater than about 100°C and less than or equal to about 250 °C, as required by Claim 11, or greater than about 100°C and less than or equal to about 150°C, as required by Claim 12. 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).
Blomberg fails to teach that the first activation energy is also provided by a plasma.
Anthis teaches methods of atomic layer etching (Paragraph [0013]). Anthis teaches a selective etching process where one material first halogenated and then reacted with another species in order to etch the halogenated material (Paragraph [0010]). Anthis teaches that the halogenation process (which can be considered an equivalent step in the etching process as the claimed modification step where the first activation energy is provided) can be accomplished with the use of plasma (Paragraph [0033]).
It would have been obvious to one of ordinary skill in the art to have modified the method of modified Blomberg, such that the first activation energy was provided with the use of plasma as taught by Anthis. With this modification a temperature would still be provided during the method, as outlined above, and therefore the limitations of the instant claim would be met.
This modification would have been obvious as it could be considered a combination of prior art elements according to known methods to yield predictable results. The combination would have had the predictable result of providing the first activation energy with a plasma. See MPEP 2143(I)(A).
Regarding Claim 13, modified Blomberg teaches all the limitations of claim 1 as outlined above.
Blomberg fails to teach wherein: the first activation energy is provided by a plasma.
Anthis teaches methods of atomic layer etching (Paragraph [0013]). Anthis teaches a selective etching process where one material first halogenated and then reacted with another species in order to etch the halogenated material (Paragraph [0010]). Anthis teaches that the halogenation process (which can be considered an equivalent step in the etching process as the claimed modification step where the first activation energy is provided) can be accomplished with the use of plasma (Paragraph [0033]).
It would have been obvious to one of ordinary skill in the art to have modified the method of modified Blomberg, such that the first activation energy was provided with the use of plasma as taught by Anthis.
This modification would have been obvious as it could be considered a combination of prior art elements according to known methods to yield predictable results. The combination would have had the predictable result of providing the first activation energy with a plasma. See MPEP 2143(I)(A).
Claims 1-4, 6-10, and 14-26 are rejected under 35 U.S.C. 103 as being unpatentable over Blomberg in view of Kanarik (US-20150020971-A1). (Note: these claims were rejected above under an interpretation that the selection of a dielectric material, in particular silicon oxide, as the material not-to-be-etched would be obvious based on the related teachings of Blomberg. This set of rejections is provided under an alternative interpretation where the selection of a dielectric material, in particular silicon oxide, as the material not-to-be-etched in relation to the etching of a semiconductor material would not be obvious based on the teachings of Blomberg).
Regarding Claim 1, Blomberg teaches a method (Paragraph [0002] etching processes taught), comprising:
providing a substrate to a processing chamber, the substrate having a semiconductor portion and another portion (Paragraph [0143] Providing a substrate with a material to be etched and may comprise material other than the etching target. Paragraph [0144] material to be etched can be Si or Ge which are semiconductors);
modifying the semiconductor portion of the substrate selective to the other portion of the substrate by flowing a first process gas comprising a first halogen species onto the substrate and providing a first activation energy to cause the first halogen species to preferentially adsorb on the semiconductor portion relative to the other portion to form a first halogenated semiconductor (Paragraph [0060] first reactant adsorbs to the material to be etched. Paragraphs [0061-0065] multiple example first reactants are taught that comprise a halogen. Paragraph [0143] etch process is selective to material to be etched relative to other materials on the substrate. Paragraph [0068] methods are thermal etching processes, where thermal energy can provide any activation energy required. Paragraph [0141] cycles are conducted with a temperature provided, thereby providing the claimed "first activation energy" Paragraph [0006] the first reactant formed a reactant species on the substrate surface); and
removing the first halogenated semiconductor by flowing a second process gas comprising a second halogen species onto the substrate and providing a second activation energy, without providing a plasma, to cause the second halogen species to react with the first halogenated semiconductor and cause the first halogenated semiconductor to desorb from the substrate (Paragraph [0006] the reactant species formed by the first reactant reacts with the second reactant to form a volatile species that is then removed from the substrate. Paragraph [0005] second reactant is a halide ligand, therefore contains a halogen. Paragraph [0068] methods are thermal etching processes, where thermal energy can provide any activation energy required and no plasma is used. Paragraph [0141] cycles are conducted with a temperature provided, thereby providing the claimed "second activation energy"),
wherein the semiconductor portion comprises one or more of silicon, germanium, silicon-germanium, or a doped silicon (Paragraph [0144] material to be etched can be Si or Ge).
Blomberg fails to teach that the other portion of the substrate is a dielectric portion.
Blomberg does teach that the substrate can comprise dielectric materials (Paragraphs [0143-0144] multiple examples of dielectric materials, such as silicon oxide), however these materials are described as potential targets for selective etching, and Blomberg fails to specify the composition of the not-to-be-etched material. However, Blomberg also provides example embodiments where silicon oxide is not etched (Paragraphs [0161-0162] Figure 6 no etching silicon oxide films or native oxide was observed in the example embodiments).
Kanarik teaches methods of processing a substrate ([Abstract]). Kanarik teaches a method of processing a substrate by atomic layer etching (Paragraphs [0063-0065]). Kanarik teaches an embodiment where silicon is the target material etched (Paragraph [0068] silicon etching as an example). Kanarik teaches that the silicon is etched by a first adsorption step (Paragraph [0068] a reactant gas adsorbs into the silicon), followed by a step of providing energy to etch the adsorbed layer (Paragraph [0075] energy from ions etches the adsorbed silicon layer). Kanarik teaches that the gas used for the adsorption step can be selected to determine etching selectivity, providing the example of creating a selectivity of silicon being etched and silicon oxide not being etched (Paragraph [0084] selectivity is improved by the reactant gas chosen. An example of etching polysilicon while oxide is not etched).
It would have been obvious to one of ordinary skill in the art to have modified the method of Blomberg such that the during the selective etching of a semiconductor material, the material on the substrate that is not etched is silicon oxide, as taught by Kanarik.
This modification would have been obvious because Blomberg teaches a selective etching process, teaches that the substrate could comprise silicon oxide, and teaches embodiments that do not etch silicon oxide. One of ordinary skill in the art could have reasonably selected a substrate that comprised silicon oxide, where the silicon oxide was not the target material of the selective etching process. This selection would have been obvious in light of the teachings of Kanarik, which teaches a process of etching where silicon is etched selectively over silicon oxide. Alternatively, this modification could be considered a combination of prior art elements according to known methods to yield predictable results. The combination would have had the predictable result of providing a substrate that comprised silicon and silicon oxide, where silicon was the target material of a selective etching process and the silicon oxide was not etched by the method. See MPEP 2143(I)(A).
Regarding Claim 2, Blomberg further teaches wherein during the removing: the second halogen species reacts with the first halogenated semiconductor to convert the first halogenated semiconductor to a second halogenated semiconductor, and the desorption of the first halogenated semiconductor includes desorption of the second halogenated semiconductor (Paragraph [0006] the reactant species formed by the first reactant reacts with the second reactant to form a volatile species that is then removed from the substrate).
Regarding Claim 3, Blomberg further teaches wherein the second halogenated semiconductor is more volatile than the first halogenated semiconductor (Paragraph [0060] first reactant adsorbs to the material to be etched while the second reactant results in the formation of volatile by-products, therefore the product formed by the second reactant, equivalent to the claimed second halogenated semiconductor, is more volatile than the product formed when the first reactant adsorbs).
Regarding Claim 4, modified Blomberg fails to explicitly teach wherein: the first halogen species comprises chlorine, the first halogenated semiconductor comprises silicon tetrachloride (SiCI4), the second halogen species comprises fluorine, and the second halogenated semiconductor comprises silicon tetrafluoride (SiF4).
However, Blomberg teaches that the first reactant can be a chlorinating agent and the second reactant can be a fluorinating agent (Paragraph [0022]). Blomberg teaches that the semiconductor portion to be etched can be silicon (Paragraph [0144]).
Examiner takes the position that it would have been obvious in an embodiment where the material to be etched is silicon and the first reactant is a chlorinating agent and the second reactant is a fluorinating agent, that the resulting material (equivalent to the claimed first halogenated semiconductor) formed when the first reactant adsorbs to the silicon of the would be silicon tetrachloride, and that the resulting material (equivalent to the claimed second halogenated semiconductor) that formed when the second reactant reacted with the modified silicon would be silicon tetrafluoride.
This would have been obvious as there are a finite number of identified and predictable potential from the chlorination and fluorination of a silicon material. See MPEP 2143(I)(E).
Regarding Claim 6, modified Blomberg teaches wherein the dielectric portion comprises one or more of an oxide or a nitride (as outlined above in regards to the rejection of Claim 1, the dielectric portion comprises silicon oxide).
Regarding Claim 7, Blomberg further teaches wherein, at the first activation energy, the semiconductor portion is halogenated by the first halogen species without halogenating the dielectric portion (Paragraph [0060] first reactant adsorbs to the material to be etched. Paragraph [0143] etch process is selective to material to be etched relative to other materials on the substrate).
Regarding Claim 8, Blomberg further teaches wherein, at the second activation energy, the first halogenated semiconductor is removed by a reaction with the second halogen species without removing the dielectric portion (Paragraph [0143] etch process is selective to material to be etched relative to other materials on the substrate. Paragraph [0148] no substantial amount of material is removed from the non-desired material).
Regarding Claim 9, Blomberg further teaches providing the first activation energy is provided by heating the substrate to a first temperature (Paragraph [0068] the etching method is a thermal etching process, where heat is provided for the activation energies required in the process. Paragraph [0141] the etching process is performed at certain temperatures. Paragraph [0162] in an example the temperature provided is described as setting the substrate to a certain temperature).
Regarding Claim 10, Blomberg further teaches wherein the first temperature is greater than about 100 °C (Paragraph [0141] the method is conducted at certain temperatures “In some embodiments, the temperature is greater than about … 100°C”).
Regarding Claim 14, Blomberg further teaches wherein the second activation energy is provided, without using a plasma, by heating the substrate to a temperature. (Paragraph [0068] the etching method is a thermal etching process, where heat is provided for the activation energies required in the process and plasma is not used. Paragraph [0141] the etching process is performed at certain temperatures. Paragraph [0162] in an example the temperature provided is described as setting the substrate to a certain temperature).
Regarding Claim 15, Blomberg further teaches wherein the temperature is greater than or equal to about 100 °C (Paragraph [0141] the method is conducted at certain temperatures “In some embodiments, the temperature is greater than about … 100°C”).
Regarding Claim 16, Blomberg fails to teach wherein the modifying is performed while the substrate is maintained at a temperature less than or equal to about 150 °C.
However, Blomberg teaches that the method is conducted at certain temperatures that can range from about 20°C to about 1200°C (Paragraph [0068] the etching method is a thermal etching process, where heat is provided for the activation energies required in the process. Paragraph [0141] the etching process is performed at certain temperatures. Paragraph [0162] in an example the temperature provided is described as setting the substrate to a certain temperature).
It would have been obvious to one of ordinary skill in the art to have selected and incorporated a temperature at a level within the disclosed range of about 20°C to about 1200°C, including at amounts that overlap with the claimed range of less than or equal to about 150 °C. 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).
Regarding Claim 17, Blomberg further teaches wherein the removing is performed while the substrate is maintained at a temperature greater than or equal to about 100 °C (Paragraph [0068] the etching method is a thermal etching process, where heat is provided for the activation energies required in the process. Paragraph [0141] the etching process is performed at certain temperatures including “In some embodiments, the temperature is greater than about … 100°C”. Paragraph [0162] in an example the temperature provided is described as setting the substrate to a certain temperature).
Regarding Claim 18, Blomberg further teaches wherein the first and second halogen species each comprise a different halogen species selected from the group consisting of fluorine, chlorine, bromine, and iodine (Paragraph [0022] the first reactant can be a chlorinating agent and the second reactant can be a fluorinating agent).
Regarding Claim 19, Blomberg further teaches wherein: the first halogen species comprises chlorine, and the second halogen species comprises fluorine (Paragraph [0022] the first reactant can be a chlorinating agent and the second reactant can be a fluorinating agent).
Regarding Claim 20, Blomberg further teaches wherein: the first halogen species comprises fluorine, and the second halogen species comprises chlorine (Paragraph [0022] the first reactant can be a fluorinating agent and the second reactant can be a chlorinating agent).
Regarding Claim 21, Blomberg further teaches wherein: the first process gas comprises chlorine (Cl2), and the second process gas comprises hydrogen fluoride (HF) (Paragraphs [0101-0102] Halide reactants can be SeO2Cl2, SO2Cl2, SeOCl2, or NCl2F which all comprise Cl2. Paragraph [0097] halide reactant can be NX, where N is hydrogen and X is fluorine).
Regarding Claim 22, Blomberg further teaches wherein the semiconductor portion comprises silicon (Paragraph [0144] material to be etched can be Si).
Regarding Claim 23, modified Blomberg teaches wherein the dielectric portion comprises a silicon oxide or a silicon nitride (as outlined above in regards to the rejection of Claim 1, the dielectric portion comprises silicon oxide).
Regarding Claim 24, Blomberg further teaches wherein the modifying of the semiconductor portion and/or the removing of the first halogenated semiconductor occurs isotropically (Paragraph [0068] the thermal ALE method can be an isotropic etching process).
Regarding Claim 25, Blomberg further teaches wherein the semiconductor portion does not comprise a silicon oxide (Paragraph [0144] material to be etched can be Ge, which would not comprise silicon oxide).
Regarding Claim 26, Blomberg further teaches that the method further comprises flowing, before or during the removing, a catalyst onto the substrate, wherein the catalyst is configured to assist with the reaction between the second halogen species and the first halogenated semiconductor (Paragraph [0078] additional reactant can be provided to improve or tune selective etching, can be provided with the second halide. This additional reactant can be considered the claimed catalyst).
Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Blomberg as applied to claims 1 and 2 above, and further in view of Nishino and Woo.
Regarding Claim 4, (Note: claim 4 was rejected above with one interpretation of obviousness and is being rejected here with an alternative interpretation in view of the prior art cited in this section) modified Blomberg teaches all the limitations of claims 1 and 2 as outlined above.
Blomberg further teaches that the first reactant can be a chlorinating agent and the second reactant can be a fluorinating agent (Paragraph [0022]). Blomberg also teaches that the semiconductor portion to be etched can be silicon (Paragraph [0144]).
Modified Blomberg fails to teach that the first halogenated semiconductor comprises silicon tetrachloride (SiCI4) and the second halogenated semiconductor comprises silicon tetrafluoride (SiF4).
Nishino teaches a method of etching (Column 1 lines 7-11). Nishino teaches when silicon atoms are etched with a chlorine gas, silicon tetrachloride can be produced (Column 1 lines 50-56).
Woo teaches a method of atomic layer etching (Paragraph [0002]). Woo teaches that in the etching process silicon atoms can combine with fluorine-containing etching gases to form silicon tetrafluoride (Paragraph [0026]).
It would have been obvious to one of ordinary skill in the art to have modified the method of modified Blomberg, such that in an embodiment of the method of modified Blomberg where silicon is being etched and the first reactant is a chlorinating agent and the second reactant is a fluorinating agent, then a result of the first reactant adsorbing to the silicon portion is the formation of silicon tetrachloride, as taught by Nishino, and a result of the second reactant etching the modified silicon surface is the formation of silicon tetrafluoride, as taught by Woo.
This modification would have been obvious as it can be considered the combination of prior art elements according to known methods to yield predictable results. The prior art, in Nishino and Woo, teach that silicon tetrachloride and silicon tetrafluoride are possible reaction products formed in the process of etching silicon atoms and this combination would have had the predictable result of forming those molecules in the process of etching silicon. See MPEP 2143(I)(A).
Claims 11-13 are rejected under 35 U.S.C. 103 as being unpatentable over Blomberg in view of Kanarik, as applied to claims 1 and 9 above, and in further view of Anthis.
Regarding Claims 11 and 12, modified Blomberg teaches all the limitations of claims 1 and 9. However Blomberg fails to teach wherein: the first activation energy is provided by heating the substrate and by a plasma, and the first temperature is less than or equal to about 250 °C, as required by Claim 11, or where the first temperature is less than or equal to about 150°C, as required by Claim 12.
However, Blomberg teaches that the method is conducted at certain temperatures that can range from about 20°C to about 1200°C and that the temperature is greater than about 100°C (Paragraph [0141]).
It would have been obvious to one of ordinary skill in the art to have selected and incorporated a temperature for conducting the method, including the step of providing a first activation energy, at a level within the disclosed range of greater than about 100°C to about 1200°C, including at amounts that overlap with the claimed range of greater than about 100°C and less than or equal to about 250 °C, as required by Claim 11, or greater than about 100°C and less than or equal to about 150°C, as required by Claim 12. 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).
Blomberg fails to teach that the first activation energy is also provided by a plasma.
Anthis teaches methods of atomic layer etching (Paragraph [0013]). Anthis teaches a selective etching process where one material first halogenated and then reacted with another species in order to etch the halogenated material (Paragraph [0010]). Anthis teaches that the halogenation process (which can be considered an equivalent step in the etching process as the claimed modification step where the first activation energy is provided) can be accomplished with the use of plasma (Paragraph [0033]).
It would have been obvious to one of ordinary skill in the art to have modified the method of modified Blomberg, such that the first activation energy was provided with the use of plasma as taught by Anthis. With this modification a temperature would still be provided during the method, as outlined above, and therefore the limitations of the instant claim would be met.
This modification would have been obvious as it could be considered a combination of prior art elements according to known methods to yield predictable results. The combination would have had the predictable result of providing the first activation energy with a plasma. See MPEP 2143(I)(A).
Regarding Claim 13, modified Blomberg teaches all the limitations of claim 1 as outlined above.
Blomberg fails to teach wherein: the first activation energy is provided by a plasma.
Anthis teaches methods of atomic layer etching (Paragraph [0013]). Anthis teaches a selective etching process where one material first halogenated and then reacted with another species in order to etch the halogenated material (Paragraph [0010]). Anthis teaches that the halogenation process (which can be considered an equivalent step in the etching process as the claimed modification step where the first activation energy is provided) can be accomplished with the use of plasma (Paragraph [0033]).
It would have been obvious to one of ordinary skill in the art to have modified the method of modified Blomberg, such that the first activation energy was provided with the use of plasma as taught by Anthis.
This modification would have been obvious as it could be considered a combination of prior art elements according to known methods to yield predictable results. The combination would have had the predictable result of providing the first activation energy with a plasma. See MPEP 2143(I)(A).
Response to Arguments
Applicant’s arguments, see Remarks Pg. 2-3, filed 10/02/2025, with respect to the 35 U.S.C. § 103 rejection have been fully considered and are not persuasive.
Applicant’s arguments with respect to claim 1 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). 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.
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/A.K.L./Examiner, Art Unit 1713
/JOSHUA L ALLEN/Supervisory Patent Examiner, Art Unit 1713