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 .
Drawings
The replacement for drawing Figure 2 was received on 09/24/2026. These drawings are accepted.
Status of the Claims
This is a final office action in response to the applicant’s arguments and remarks filed on 09/24/2026. Claims 1-20 are pending in the current office action. Claims 1, 6, 11, 13, 18 have been amended by the applicant.
Status of the Rejection
The drawing objections have been overcome by the applicant's amendments.
All 35 U.S.C. § 112(b) and 112(d) rejections from the previous office action are withdrawn in view of the Applicant’s amendment.
All 35 U.S.C. § 102 and 103 rejections from the previous office action are withdrawn in view of the Applicant’s amendment.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, 7-8, and 11-12 are rejected under 35 U.S.C. 103 as being unpatentable over Lee et al. (US-20230116213-A1) in view of Wang et al. (US-20230290647-A1).
Regarding Claim 1 Lee teaches a semiconductor processing method (Paragraphs [0015-0018] methods related to semiconductor device fabrication) comprising:
providing a boron-and-halogen-containing precursor and an oxygen-containing precursor to a processing region of a semiconductor processing chamber (Paragraph [0047] the absorber layer can be etched with a gas that includes BCl3 and O2. Paragraph [0058] the etching process can be a RIE etching process), wherein a substrate is housed in the processing region, wherein a layer of metal-containing hardmask material is disposed on the substrate, and wherein a layer of silicon-containing material is disposed on the layer of metal-containing hardmask material (Paragraphs [0041-0046] the absorber layer (element 140) can comprise a transition metal as the main alloy element within it. Paragraph [0048] Figure 3E a hard mask layer (element 160) is disposed over the absorber layer and can be silicon oxide. Paragraph [0061] Figure 3I the absorber layer is used as a mask in later processes step to etch the second capping layer (element 130));
forming plasma effluents of the boron-and-halogen-containing precursor and the oxygen-containing precursor (Paragraph [0047] the absorber layer can be etched with a gas that includes BCl3 and O2. Paragraph [0058] the etching process can be a RIE etching process); and
contacting the substrate with the plasma effluents of the boron-and-halogen-containing precursor and the oxygen-containing precursor, wherein the contacting etches a feature in the layer of metal-containing hardmask material (Paragraph [0047] the absorber layer can be etched with a gas that includes BCl3 and O2. Paragraph [0058] the etching process can be a RIE etching process), and wherein the contacting forms a layer of passivation material on sidewalls of the feature in the layer of metal-containing hardmask material (Lee is silent on the formation of a passivation material on sidewalls. However, given that the method based on the disclosure in Lee, as outlined above, is substantially similar to that in instant claims, it is the examiner's position that the formation of a passivation material on the sidewalls would have inherently occurred as part of the method as instantly claimed. Since PTO cannot conduct experiments the proof of burden is shifted to the applicants to establish a nonobviousness difference. See MPEP 2112. When the structure recited in the reference is substantially identical to that of the claims, claimed properties or functions are presumed to be inherent. The Courts have held that it is well settled that where there is a reason to believe that a functional characteristic would be inherent in the prior art, the burden of proof then shifts to the applicant to provide objective evidence to the contrary. See MPEP 2112.01(I)).
Lee fails to teach wherein the semiconductor processing chamber operating temperature is greater than or about 200°C. However, Lee teaches that the etch rate and the etch selectivity of the etching process are dependent on the temperature of the substrate (Paragraph [0058]).
Wang teaches methods that include etching a metal-containing material (Paragraph [0001]). Wang teaches that the metal containing material can include tungsten (Paragraph [0043]). Wang teaches that the etching process utilizes a fluorine-containing precursor and a secondary gas that are formed into a plasma (Paragraph [0052]). Wang teaches that the fluorine-containing precursor can be a chlorine precursor, such as boron trichloride (Paragraph [0055]). Wang teaches that the secondary gas can be an oxygen-containing precursor (Paragraph [0057]). Wang teaches that the operating temperature of the process can be greater than or about 200°C (Paragraph [0058]).
It would have been obvious to one of ordinary skill in the art to have modified the method of Lee by selecting an operating temperature of 200°C or greater, as taught by Wang.
One of ordinary skill in the art would have been motivated to make this modification because Wang teaches that this is a suitable temperature range for an etching process of metal materials using similar etching precursors and Lee teaches wherein that the temperature is a result effective variable. Specifically, Lee teaches that the etch rate and etch selectivity depend on the temperature of the substrate. Since this particular parameter is recognized as result-effective variable, i.e. a variable which achieves a recognized result, the determination of the optimum or workable ranges of said variable can be characterized as routine experimentation. See In re Boesch, 617 F. 2d 272, 205 U.S.P.Q. 215 (C.C.P.A. 1980). Thus, it would be obvious to one skilled in the art at the time of the claimed invention to modify the operating temperature, to yield the expected result of an operating temperature of 200°C or greater. Alternatively, 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 modification would have provided the predictable result of providing a suitable temperature for conducting the etching process. See MPEP 2143(I)(A).
Regarding Claim 2, Lee teaches wherein the boron-and-halogen-containing precursor comprises boron trichloride (BCl3) (Paragraph [0047] BCl3 can be used in the dry etch).
Regarding Claim 3, Lee teaches wherein the oxygen-containing precursor comprises diatomic oxygen (O2) (Paragraph [0047] O2 can be used in the dry etch).
Regarding Claim 4, Lee teaches wherein the layer of metal-containing hardmask material comprises tungsten (Paragraphs [0041-0046] the absorber layer (element 140) can comprise a transition metal as the main alloy element within it).
Regarding Claim 7, Lee teaches wherein the layer of metal-containing hardmask material is characterized by a metal content of greater than or about 40 at.% (Paragraph [0045] the main alloy in the absorber comprises more than 50 atomic percent of the alloy).
Regarding Claim 8, Lee teaches wherein the layer of silicon-containing material comprises silicon oxide (Paragraph [0048] Figure 3E a hard mask layer (element 160) is disposed over the absorber layer and can be silicon oxide).
Regarding Claim 11, Wang further teaches that the operating temperature of the process can be greater than or about 300°C (Paragraph [0058]).
It would have been obvious to one of ordinary skill in the art to have modified the method of modified Lee, as outlined above, by selecting an operating temperature of 300°C or greater, as taught by Wang.
One of ordinary skill in the art would have been motivated to make this modification because Wang teaches that this is a suitable temperature range for an etching process of metal materials using similar etching precursors and Lee teaches wherein that the temperature is a result effective variable. Specifically, Lee teaches that the etch rate and etch selectivity depend on the temperature of the substrate. Since this particular parameter is recognized as result-effective variable, i.e. a variable which achieves a recognized result, the determination of the optimum or workable ranges of said variable can be characterized as routine experimentation. See In re Boesch, 617 F. 2d 272, 205 U.S.P.Q. 215 (C.C.P.A. 1980). Thus, it would be obvious to one skilled in the art at the time of the claimed invention to modify the operating temperature, to yield the expected result of an operating temperature of 200°C or greater. Alternatively, 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 modification would have provided the predictable result of providing a suitable temperature for conducting the etching process. See MPEP 2143(I)(A).
Regarding Claim 12, Lee teaches wherein the boron-and-halogen-containing precursor and the oxygen-containing precursor are silicon-free (Paragraph [0047] the absorber layer can be etched with a gas that includes BCl3 and O2, which do not contain silicon).
Claims 1 and 9 are rejected under 35 U.S.C. 103 as being unpatentable over Lee in view of Ni et al. (US-6465159-B1) and Wang.
Regarding Claim 1, (Note: Claim 1 was rejected above under an interpretation that the formation of a passivation material on sidewalls of the feature would be an inherent result of the etching method taught by Lee. An alternative rejection is formulated here for claim 1 where that claimed limitation is not interpreted as inherent) Lee teaches a semiconductor processing method (Paragraphs [0015-0018] methods related to semiconductor device fabrication) comprising:
providing a boron-and-halogen-containing precursor and an oxygen-containing precursor to a processing region of a semiconductor processing chamber (Paragraph [0047] the absorber layer can be etched with a gas that includes BCl3 and O2. Paragraph [0058] the etching process can be a RIE etching process), wherein a substrate is housed in the processing region, wherein a layer of metal-containing hardmask material is disposed on the substrate, and wherein a layer of silicon-containing material is disposed on the layer of metal-containing hardmask material (Paragraphs [0041-0046] the absorber layer (element 140) can comprise a transition metal as the main alloy element within it. Paragraph [0048] Figure 3E a hard mask layer (element 160) is disposed over the absorber layer and can be silicon oxide. Paragraph [0061] Figure 3I the absorber layer is used as a mask in later processes step to etch the second capping layer (element 130));
forming plasma effluents of the boron-and-halogen-containing precursor and the oxygen-containing precursor (Paragraph [0047] the absorber layer can be etched with a gas that includes BCl3 and O2. Paragraph [0058] the etching process can be a RIE etching process); and
contacting the substrate with the plasma effluents of the boron-and-halogen-containing precursor and the oxygen-containing precursor, wherein the contacting etches a feature in the layer of metal-containing hardmask material (Paragraph [0047] the absorber layer can be etched with a gas that includes BCl3 and O2. Paragraph [0058] the etching process can be a RIE etching process).
Lee fails to teach that the contacting forms a layer of passivation material on sidewalls of the feature in the layer of metal-containing hardmask material.
Ni teaches methods related to semiconductor processing and etching (Column 1 lines 5-7). Ni teaches a method of etching that utilizes an oxidizing gas, that comprises oxygen, and a passivation gas, where the passivation gas can be a boron containing gas, that react to form a passivation film on sidewalls during etching (Column 2 lines 26-46). Ni teaches that the boron containing gas can be BCl3 (Column 4 lines 14-17). Ni teaches that the passivation film formed can be B2O2 (Column 4 lines 18-28).
It would have been obvious to one of ordinary skill in the art to have modified the method of Lee by including within the etching process the formation of a passivation film made of byproducts of the etching gases on the sidewalls of the feature being etched, as taught by Ni.
This modification would have been obvious to one of ordinary skill in the art because it can be considered the combination of prior art elements according to known methods to yield predictable results. Lee teaches an etching process and Ni teaches that a similar etching process, utilizing similar etching gases, that a passivation film layer is formed on the sidewalls of the etched feature. This combination would have had the predictable result of forming a passivation layer on sidewalls during the etching process. See MPEP 2143(I)(A).
Lee fails to teach wherein the semiconductor processing chamber operating temperature is greater than or about 200°C. However, Lee teaches that the etch rate and the etch selectivity of the etching process are dependent on the temperature of the substrate (Paragraph [0058]).
Wang teaches methods that include etching a metal-containing material (Paragraph [0001]). Wang teaches that the metal containing material can include tungsten (Paragraph [0043]). Wang teaches that the etching process utilizes a fluorine-containing precursor and a secondary gas that are formed into a plasma (Paragraph [0052]). Wang teaches that the fluorine-containing precursor can be a chlorine precursor, such as boron trichloride (Paragraph [0055]). Wang teaches that the secondary gas can be an oxygen-containing precursor (Paragraph [0057]). Wang teaches that the operating temperature of the process can be greater than or about 200°C (Paragraph [0058]).
It would have been obvious to one of ordinary skill in the art to have modified the method of Lee by selecting an operating temperature of 200°C or greater, as taught by Wang.
One of ordinary skill in the art would have been motivated to make this modification because Wang teaches that this is a suitable temperature range for an etching process of metal materials using similar etching precursors and Lee teaches wherein that the temperature is a result effective variable. Specifically, Lee teaches that the etch rate and etch selectivity depend on the temperature of the substrate. Since this particular parameter is recognized as result-effective variable, i.e. a variable which achieves a recognized result, the determination of the optimum or workable ranges of said variable can be characterized as routine experimentation. See In re Boesch, 617 F. 2d 272, 205 U.S.P.Q. 215 (C.C.P.A. 1980). Thus, it would be obvious to one skilled in the art at the time of the claimed invention to modify the operating temperature, to yield the expected result of an operating temperature of 200°C or greater. Alternatively, 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 modification would have provided the predictable result of providing a suitable temperature for conducting the etching process. See MPEP 2143(I)(A).
Regarding Claim 9, Lee teaches all the limitations of claim 1 as outlined above.
Lee fails to teach that the layer of passivation material comprises a boron-and-oxygen-containing material.
Ni teaches methods related to semiconductor processing and etching (Column 1 lines 5-7). Ni teaches a method of etching that utilizes an oxidizing gas, that comprises oxygen, and a passivation gas, where the passivation gas can be a boron containing gas, that react to form a passivation film on sidewalls during etching (Column 2 lines 26-46). Ni teaches that the boron containing gas can be BCl3 (Column 4 lines 14-17). Ni teaches that the passivation film formed can be B2O2 (Column 4 lines 18-28).
It would have been obvious to one of ordinary skill in the art to have modified the method of Lee such that the passivation material that formed on the sidewalls of the feature during the etching process comprised B2O2, as taught by Ni.
This modification would have been obvious to one of ordinary skill in the art because it can be considered the combination of prior art elements according to known methods to yield predictable results. This combination would have had the predictable result of forming a passivation layer on sidewalls during the etching process that comprised B2O2. See MPEP 2143(I)(A).
Claims 5-6 are rejected under 35 U.S.C. 103 as being unpatentable over Lee in view of Wang, as applied to claim 1 above, and further in view of Yoon et al. (US-20160314981-A1).
Regarding Claims 5 and 6, Lee teaches all the limitations of claim 1 as outlined above.
Lee fails to teach that a halogen-containing precursor is provided to the processing region with the boron-and-halogen-containing precursor, as required by claim 5, or that the halogen-containing precursor comprises diatomic chlorine (Cl2), hydrogen bromide (HBr), or both, as required by claim 6.
Yoon teaches methods of forming patterns for semiconductors (Paragraph [0001]). Yoon teaches a method of etching where an etch gas, that can comprise BCl3, is supplied for a plasma etching process to etch a metal-containing layer (Paragraph [0052]). Yoon teaches that the etch gas can further comprise additional gases, for example a fluorine containing gas or an additional chlorine containing gas such as Cl2 (Paragraph [0052]).
It would have been obvious to one of ordinary skill in the art to have modified the method of Lee by including an additional gas with the boron-and-halogen-containing precursor, as taught by Yoon.
This modification would have been obvious as it could be considered the combination of prior art elements according to known methods to yield predictable results. This combination would have had the predictable result of supplying a gas suitable for use in a plasma etching process to etch and metal containing layer. See MPEP 2143(I)(A).
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over Lee in view of Wang, as applied to claim 1 above, and further in view of Raley et al. (US-20230260801-A1).
Regarding Claim 10, Lee teaches all the limitations of claim 1 as outlined above.
Lee fails to teach wherein the feature in the layer of metal-containing hardmask material is characterized by a critical dimension of less than or about 20 nm.
Raley teaches methods related to processing a substrate (Paragraph [0002]). Raley teaches a method where a hard mask that can comprise tungsten is etched to form a recess (Paragraphs [0025-000029] Figures 1A and 1B hard mask layer (element 140) can comprise tungsten and is etched to form recesses (element 155)). Raley teaches that the critical dimension of the recess can be 8-40nm (Paragraph [0029]).
It would have been obvious to one of ordinary skill in the art to have modified the method of Lee by selecting as a critical dimension for the feature etched in the metal-containing layer, a critical dimension within the range taught by Raley.
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. Lee teaches a method of etching a feature in a metal-containing layer, but does not teach the critical dimension of feature etched, while Raley teaches a critical dimension that can be etched into a metal-containing feature. This combination would have had the predictable result of setting a particular critical dimension for the feature etched. See MPEP 2143(I)(A).
It would have been obvious to one of ordinary skill in the art to have selected and incorporated a critical dimension of the feature at a level within the disclosed range of 8-40nm, including at amounts that overlap with the claimed range of less than or about 20nm. 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).
Claims 13-14 and 16-20 are rejected under 35 U.S.C. 103 as being unpatentable over Yoon in view of Wang and Lee.
Regarding Claim 13, Yoon teaches a semiconductor processing method (Paragraph [0002] methods of forming patterns for semiconductors) comprising:
i) providing a boron-and-halogen-containing precursor to a processing region of a semiconductor processing chamber (Paragraph [0052] Figure 1B an etch gas, that can be BCl3, which is boron-and-halogen-containing, is used in a plasma etch process to etch the metal-containing layer. Paragraph [0091] process gas is supplied to the plasma limitation area), wherein a substrate is housed in the processing region, wherein a layer of metal-containing hardmask material is disposed on the substrate, and wherein a layer of silicon-containing material is disposed on the layer of metal-containing hardmask material (Paragraphs [0049-0050] Figure 1A substrate is provided that comprises a metal layer (element 12) with a mask layer (element 13) over the metal layer, where the mask layer can be silicon oxide or silicon nitride. Paragraphs [0087-0091] process can be conducted within apparatus shown in Figure 6A, where the substrate (element 90) is provided to the region including plasma limitation area (element 1111) for the operations, where the precursors are supplied to the plasma limitation area for the operations);
ii) forming plasma effluents of the boron-and-halogen-containing precursor (Paragraph [0052] Figure 1B an etch gas, that can be BCl3, which is boron-and-halogen-containing, is used in a plasma etch process to etch the metal-containing layer. Paragraph [0096] plasma is generated and used to treat the substrate);
iii) contacting the substrate with the plasma effluents of the boron-and-halogen-containing precursor, wherein the contacting etches a feature in the layer of metal-containing hardmask material (Paragraph [0052] Figure 1B an etch gas, that can be BCl3, which is boron-and-halogen-containing, is used in a plasma etch process to etch the metal-containing layer. Paragraph [0096] plasma is generated and used to treat the substrate);
iv) providing an oxygen-containing precursor to the processing region of the semiconductor processing chamber (Paragraph [0056] Figure 1C oxygen (O2) is used in a plasma process to form a passivation layer (element 15a) over exposed portions of the metal-containing layer. Paragraphs [0087-0091] process can be conducted within apparatus shown in Figure 6A, where the substrate (element 90) is provided to the region including plasma limitation area (element 1111) for the operations, where the precursors are supplied to the plasma limitation area for the operations); and
v) contacting the substrate with the oxygen-containing precursor, wherein the contacting oxidizes a portion of sidewalls of the feature in the layer of metal-containing hardmask material (Paragraph [0056] Figure 1C oxygen (O2) is used in a plasma process to form a passivation layer (element 15a) over exposed portions of the metal-containing layer).
Yoon fails to teach wherein the semiconductor processing chamber operating temperature is greater than or about 200°C.
Lee teaches a semiconductor processing method (Paragraphs [0015-0018] methods related to semiconductor device fabrication) comprising: providing a boron-and-halogen-containing precursor and an oxygen-containing precursor to a processing region of a semiconductor processing chamber (Paragraph [0047] the absorber layer can be etched with a gas that includes BCl3 and O2. Paragraph [0058] the etching process can be a RIE etching process), wherein a substrate is housed in the processing region, wherein a layer of metal-containing hardmask material is disposed on the substrate, and wherein a layer of silicon-containing material is disposed on the layer of metal-containing hardmask material (Paragraphs [0041-0046] the absorber layer (element 140) can comprise a transition metal as the main alloy element within it. Paragraph [0048] Figure 3E a hard mask layer (element 160) is disposed over the absorber layer and can be silicon oxide. Paragraph [0061] Figure 3I the absorber layer is used as a mask in later processes step to etch the second capping layer (element 130)); forming plasma effluents of the boron-and-halogen-containing precursor and the oxygen-containing precursor (Paragraph [0047] the absorber layer can be etched with a gas that includes BCl3 and O2. Paragraph [0058] the etching process can be a RIE etching process); and contacting the substrate with the plasma effluents of the boron-and-halogen-containing precursor and the oxygen-containing precursor, wherein the contacting etches a feature in the layer of metal-containing hardmask material (Paragraph [0047] the absorber layer can be etched with a gas that includes BCl3 and O2. Paragraph [0058] the etching process can be a RIE etching process). Lee further teaches that the etch rate and the etch selectivity of the etching process are dependent on the temperature of the substrate (Paragraph [0058]).
Wang teaches methods that include etching a metal-containing material (Paragraph [0001]). Wang teaches that the metal containing material can include tungsten (Paragraph [0043]). Wang teaches that the etching process utilizes a fluorine-containing precursor and a secondary gas that are formed into a plasma (Paragraph [0052]). Wang teaches that the fluorine-containing precursor can be a chlorine precursor, such as boron trichloride (Paragraph [0055]). Wang teaches that the secondary gas can be an oxygen-containing precursor (Paragraph [0057]). Wang teaches that the operating temperature of the process can be greater than or about 200°C (Paragraph [0058]).
It would have been obvious to one of ordinary skill in the art to have modified the method of Yoon by selecting an operating temperature of 200°C or greater, as taught by Wang.
One of ordinary skill in the art would have been motivated to make this modification because Wang teaches that this is a suitable temperature range for an etching process of metal materials using similar etching precursors and Lee teaches wherein that the temperature is a result effective variable. Specifically, Lee teaches that the etch rate and etch selectivity depend on the temperature of the substrate. Since this particular parameter is recognized as result-effective variable, i.e. a variable which achieves a recognized result, the determination of the optimum or workable ranges of said variable can be characterized as routine experimentation. See In re Boesch, 617 F. 2d 272, 205 U.S.P.Q. 215 (C.C.P.A. 1980). Thus, it would be obvious to one skilled in the art at the time of the claimed invention to modify the operating temperature, to yield the expected result of an operating temperature of 200°C or greater. Alternatively, 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 modification would have provided the predictable result of providing a suitable temperature for conducting the etching process. See MPEP 2143(I)(A).
Regarding Claim 14, Yoon teaches that the method further comprises: providing one or more halogen-containing precursors to the processing region of the semiconductor processing chamber with the boron-and-halogen-containing precursor (Paragraph [0052] the etch gas can a mixed gas of the chlorine-containing gas and a fluorine-containing gas).
Regarding Claim 16, Yoon teaches wherein operations i) through v) are repeated for a second cycle (Paragraphs [0057-0059] the etch process step and passivation step are repeated as showing in Figures 1D and 1F. Paragraph [0062] process can be a cyclic process).
Regarding Claim 17, Yoon teaches wherein repeating operation iii) in the second cycle forms a layer of passivation material on the sidewalls of the feature in the layer of metal-containing hardmask material (Paragraph [0059] Figure 1F a second passivation layer (element 15b) is formed on sidewalls of metal layer (element 12)).
Regarding Claim 18, Yoon teaches a semiconductor processing method (Paragraph [0002] methods of forming patterns for semiconductors) comprising:
providing a boron-and-halogen-containing precursor to a processing region of a semiconductor processing chamber (Paragraph [0052] Figure 1B an etch gas, that can be BCl3, which is boron-and-halogen-containing, is used in a plasma etch process to etch the metal-containing layer. Paragraph [0091] process gas is supplied to the plasma limitation area), wherein a substrate is housed in the processing region, wherein a layer of metal-containing hardmask material is disposed on the substrate, and wherein a patterned layer of silicon-containing material is disposed on the layer of metal-containing hardmask material (Paragraphs [0049-0050] Figure 1A substrate is provided that comprises a metal layer (element 12) with a mask layer (element 13) over the metal layer, where the mask layer can be silicon oxide or silicon nitride. The mask layer is patterned to have an opening (element 17). Paragraphs [0087-0091] process can be conducted within apparatus shown in Figure 6A, where the substrate (element 90) is provided to the region including plasma limitation area (element 1111) for the operations, where the precursors are supplied to the plasma limitation area for the operations);
forming plasma effluents of the boron-and-halogen-containing precursor (Paragraph [0052] Figure 1B an etch gas, that can be BCl3, which is boron-and-halogen-containing, is used in a plasma etch process to etch the metal-containing layer. Paragraph [0096] plasma is generated and used to treat the substrate);
contacting the substrate with the plasma effluents of the boron-and-halogen-containing precursor, wherein the contacting etches a first portion of a feature in the layer of metal-containing hardmask material (Paragraph [0052] Figure 1B an etch gas, that can be BCl3, which is boron-and-halogen-containing, is used in a plasma etch process to etch the metal-containing layer. Paragraph [0096] plasma is generated and used to treat the substrate),
providing an oxygen-containing precursor to the processing region of the semiconductor processing chamber (Paragraph [0056] Figure 1C oxygen (O2) is used in a plasma process to form a passivation layer (element 15a), that can comprise oxidizing a tungsten layer, over exposed portions of the metal-containing layer. Paragraphs [0087-0091] process can be conducted within apparatus shown in Figure 6A, where the substrate (element 90) is provided to the region including plasma limitation area (element 1111) for the operations, where the precursors are supplied to the plasma limitation area for the operations);
contacting the substrate with the oxygen-containing precursor, wherein the contacting oxidizes sidewalls of the feature in the layer of metal-containing hardmask material (Paragraph [0056] Figure 1C oxygen (O2) is used in a plasma process to form a passivation layer (element 15a), that can comprise oxidizing a tungsten layer, over exposed portions of the metal-containing layer);
providing the boron-and-halogen-containing precursor to the processing region of the semiconductor processing chamber (Paragraph [0057] Figure 1D an etch gas, that can be BCl3, which is boron-and-halogen-containing, is used in a plasma etch process to etch the metal-containing layer and forms a polymer layer (element 16) on sidewalls of the feature. Paragraphs [0087-0091] process can be conducted within apparatus shown in Figure 6A, where the substrate (element 90) is provided to the region including plasma limitation area (element 1111) for the operations, where the precursors are supplied to the plasma limitation area for the operations);
forming plasma effluents of the boron-and-halogen-containing precursor (Paragraph [0057] Figure 1D an etch gas, that can be BCl3, which is boron-and-halogen-containing, is used in a plasma etch process to etch the metal-containing layer and forms a polymer layer (element 16) on sidewalls of the feature. Paragraph [0096] plasma is generated and used to treat the substrate); and
contacting the substrate with the plasma effluents of the boron-and-halogen-containing precursor, wherein the contacting etches a second portion of the feature in the layer of metal-containing hardmask material, and wherein the contacting forms a layer of passivation material on sidewalls of the feature in the layer of metal-containing hardmask material (Paragraph [0057] Figure 1D an etch gas, that can be BCl3, which is boron-and-halogen-containing, is used in a plasma etch process to etch the metal-containing layer and forms a polymer layer (element 16) on sidewalls of the feature. Paragraph [0096] plasma is generated and used to treat the substrate).
Yoon fails to teach wherein the semiconductor processing chamber operating temperature is greater than or about 200°C.
Lee teaches a semiconductor processing method (Paragraphs [0015-0018] methods related to semiconductor device fabrication) comprising: providing a boron-and-halogen-containing precursor and an oxygen-containing precursor to a processing region of a semiconductor processing chamber (Paragraph [0047] the absorber layer can be etched with a gas that includes BCl3 and O2. Paragraph [0058] the etching process can be a RIE etching process), wherein a substrate is housed in the processing region, wherein a layer of metal-containing hardmask material is disposed on the substrate, and wherein a layer of silicon-containing material is disposed on the layer of metal-containing hardmask material (Paragraphs [0041-0046] the absorber layer (element 140) can comprise a transition metal as the main alloy element within it. Paragraph [0048] Figure 3E a hard mask layer (element 160) is disposed over the absorber layer and can be silicon oxide. Paragraph [0061] Figure 3I the absorber layer is used as a mask in later processes step to etch the second capping layer (element 130)); forming plasma effluents of the boron-and-halogen-containing precursor and the oxygen-containing precursor (Paragraph [0047] the absorber layer can be etched with a gas that includes BCl3 and O2. Paragraph [0058] the etching process can be a RIE etching process); and contacting the substrate with the plasma effluents of the boron-and-halogen-containing precursor and the oxygen-containing precursor, wherein the contacting etches a feature in the layer of metal-containing hardmask material (Paragraph [0047] the absorber layer can be etched with a gas that includes BCl3 and O2. Paragraph [0058] the etching process can be a RIE etching process). Lee further teaches that the etch rate and the etch selectivity of the etching process are dependent on the temperature of the substrate (Paragraph [0058]).
Wang teaches methods that include etching a metal-containing material (Paragraph [0001]). Wang teaches that the metal containing material can include tungsten (Paragraph [0043]). Wang teaches that the etching process utilizes a fluorine-containing precursor and a secondary gas that are formed into a plasma (Paragraph [0052]). Wang teaches that the fluorine-containing precursor can be a chlorine precursor, such as boron trichloride (Paragraph [0055]). Wang teaches that the secondary gas can be an oxygen-containing precursor (Paragraph [0057]). Wang teaches that the operating temperature of the process can be greater than or about 200°C (Paragraph [0058]).
It would have been obvious to one of ordinary skill in the art to have modified the method of Yoon by selecting an operating temperature of 200°C or greater, as taught by Wang.
One of ordinary skill in the art would have been motivated to make this modification because Wang teaches that this is a suitable temperature range for an etching process of metal materials using similar etching precursors and Lee teaches wherein that the temperature is a result effective variable. Specifically, Lee teaches that the etch rate and etch selectivity depend on the temperature of the substrate. Since this particular parameter is recognized as result-effective variable, i.e. a variable which achieves a recognized result, the determination of the optimum or workable ranges of said variable can be characterized as routine experimentation. See In re Boesch, 617 F. 2d 272, 205 U.S.P.Q. 215 (C.C.P.A. 1980). Thus, it would be obvious to one skilled in the art at the time of the claimed invention to modify the operating temperature, to yield the expected result of an operating temperature of 200°C or greater. Alternatively, 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 modification would have provided the predictable result of providing a suitable temperature for conducting the etching process. See MPEP 2143(I)(A).
Regarding Claim 19, Yoon teaches wherein the boron-and-halogen-containing precursor comprises boron trichloride (BCl3) (Paragraphs [0052] and [0057] BCl3 can be used in the etch gas).
Regarding Claim 20, Yoon teaches that the method further comprises: forming plasma effluents of the oxygen-containing precursor (Paragraph [0056] Figure 1C oxygen (O2) is used in a plasma process to form a passivation layer (element 15a), that can comprise oxidizing a tungsten layer, over exposed portions of the metal-containing layer. Paragraph [0096] plasma is generated and used to treat the substrate).
Claim 15 is rejected under 35 U.S.C. 103 as being unpatentable over Yoon in view of Lee and Wang, as applied to claims 13 and 14 above, and further in view of Liu et al. (US-20220382772-A1) and Leung et al. (WO-2022231815-A1).
Regarding Claim 15, Yoon teaches all the limitations of claims 13 and 14 as outlined above.
Yoon further teaches that one or more halogen-containing precursors can be supplied with the boron-and-halogen precursor, and that CF4 and CHF3 can be used as the additional halogen-containing precursors (Paragraph [0052]).
Yoon fails to teach wherein a flow rate ratio of the one or more halogen-containing precursors relative to the boron-and-halogen-containing precursor is greater than or about 50:1.
Leung teaches method relating to semiconductor processes (Paragraph [0002]). Leung teaches a method of etching photomask layers that comprise a plasma etching process where the etching gas comprises a first fluorine-containing precursor and a second halogen-containing precursor (Paragraphs [0006-0008]). Leung teaches that the first fluorine-containing precursor can be CF4 or CHF3 and that the second-halogen-containing precursor can be BCl3 (Paragraph [0046]). Leung teaches that the flow rate ratio between the first fluorine-containing precursor and the second halogen-containing precursor can be greater than 10:1 (Paragraph [0048]).
Liu teaches a method of plasma etching where the etching gases used include BCl3 and fluorine-containing gas ([Abstract]). Liu teaches that by adjusting the flow rate ratio of the gases used during etching the desired etching rate and desired shaped created by the etching process can be achieved (Paragraph [0044]).
It would have been obvious to one of ordinary skill in the art to have modified the method of Yoon by adjusting the flow rate ratios of the etching gases such that a selection was made of a flow rate ratio of CF4 and/or CHF3, which can be considered the one or more halogen-containing precursors, relative to BCl3, which can be considered the boron-and-halogen-containing precursor, to be within the flow rate ratio range taught by Leung.
One of ordinary skill in the art would have been motivated to make this modification because the Liu teaches that the flow rate ratios are result-effective variable. Specifically, Liu teaches that the etching rate and the etching shape created depend on flow rate ratio of the etching gases used in the process. Since this particular parameter is recognized as result-effective variable, i.e. a variable which achieves a recognized result, the determination of the optimum or workable ranges of said variable can be characterized as routine experimentation. See In re Boesch, 617 F. 2d 272, 205 U.S.P.Q. 215 (C.C.P.A. 1980). Additionally, 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. Yoon teaches the use of a multiple gases within the etching gas provided, while Leung teaches a suitable flow rate ratio of multiple gases in a similar etching process. This combination would have had the predictable result of providing a flow rate ratio suitable for completing the etching process as desired. See MPEP 2143(I)(A)
It would have been obvious to one of ordinary skill in the art to have selected and incorporated a flow rate ratio at a level within the disclosed range of greater than 10:1, including at amounts that overlap with the claimed range of greater than or about 50:1. 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).
Response to Arguments
Applicant’s arguments with respect to the amended claims 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 /DUY VU N DEO/Primary Examiner, Art Unit 1713
