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 .
Claim Rejections - 35 USC § 103
The following is a quotation of 35 U.S.C. 103 which forms the basis for all obviousness rejections set forth in this Office action:
A patent for a claimed invention may not be obtained, notwithstanding that the claimed invention is not identically disclosed as set forth in section 102, if the differences between the claimed invention and the prior art are such that the claimed invention as a whole would have been obvious before the effective filing date of the claimed invention to a person having ordinary skill in the art to which the claimed invention pertains. Patentability shall not be negated by the manner in which the invention was made.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claim(s) 1-29 is/are rejected under 35 U.S.C. 103 as being unpatentable over Matsushima (US 2017/0017151; IDS, 08/10/2023) in view of Spurlin (US 2015/0376792; IDS, 08/10/2023).
Matsushima is directed to a reflective mask cleaning apparatus and method of cleaning a reflective mask. Matsushima discloses and illustrates a dry cleaning apparatus 102. (Para, 0144; Fig.3). Matsushima discloses the dry cleaning apparatus 102 is a dual-frequency plasma processing apparatus. (Para, 0145; Fig.3). Matsushima discloses the dry cleaning apparatus 102 is provided with a cleaning chamber 161, a gate valve 177, a gas supply section 168, an evacuation section 169, and a control section 140. (Para, 0146; Fig.3). Matsushima discloses the cleaning chamber 161 is formed from a conductive material such as aluminum and it can maintain a reduced-pressure atmosphere. (Para, 0147; Fig.3). Matsushima discloses a processing gas introduction port 162 for introducing a processing gas G is provided in the central portion of the ceiling of the cleaning chamber 161 and the processing gas G is supplied from the supply section 168 through the processing gas introduction port 162 into the cleaning chamber 161. (Para, 0147). Matsushima discloses when the processing gas G is supplied into the cleaning chamber 161, the flow rate, pressure and the like of the processing gas G are adjusted by an adjustment device incorporated in the gas supply section 168. (Para, 0148). Matsushima discloses the processing gas G can be a reducing gas such as ammonia gas, hydrogen gas, a mixed gas of ammonia gas and hydrogen gas, or a mixed gas of hydrogen gas and nitrogen gas. (Para, 0150). Matsushima explains the reducing gas only needs to be a gas containing ammonia or hydrogen and so it may be a gas containing only ammonia gas, a gas containing only hydrogen gas, or a mixed gas of nitrogen gas and at least one of ammonia and hydrogen gas. (Para, 0150). These disclosures teach and/or suggest the limitations of claim 23, ‘An apparatus for reducing ruthenium (RU) oxides on an extreme ultraviolet (EUV) photomask, comprising: an EUV photomask processing chamber with a photomask support body attached to a photomask support, the photomask support body supporting an EUV photomask when present; a reducing agent gas supply fluidly connected to the EUV photomask processing chamber…a first valve that controls a reducing agent gas that enters into the EUV photomask processing chamber; a second valve that controls effluent gases that exit the EUV photomask processing chamber; and a controller that regulates the first valve and the second valve to adjust a pressure inside of the EUV photomask processing chamber…’ These disclosures and illustrations also teach and/or suggest the limitations of claim 24, ‘An apparatus for reducing ruthenium (RU) oxides on an extreme ultraviolet (EUV) photomask, comprising: an EUV photomask processing chamber with a photomask support body attached to a photomask support, the photomask support body supporting an EUV photomask when present; a reducing agent gas supply fluidly connected to the EUV photomask processing chamber; a carrier gas supply fluidly connected to the EUV photomask processing chamber…’ Moreover, these disclosures teach and/or suggest the limitations of claim 27, ‘An apparatus for reducing ruthenium (RU) oxides on an extreme ultraviolet (EUV) photomask, comprising: an EUV photomask processing chamber with a photomask support body attached to a photomask support, the photomask support body supporting an EUV photomask when present; a reducing agent gas supply fluidly connected to the EUV photomask processing chamber; a carrier gas supply fluidly connected to the EUV photomask processing chamber…’
Matsushima discloses a dielectric window 164 made of a dielectric material (such as quartz) is provided in the ceiling portion of the cleaning chamber 161 radially outside the processing gas introduction port 162 and a coil 165 made of a conductor is provided on the surface of the dielectric window 164, one end of the coil 165 is grounded and the other end of the coil 165 is connected to a high-frequency power supply 180 through a matching device 166. (Para, 0151). Matsushima discloses a space 163 for dry cleaning the to-be-cleaned object W is provided inside the cleaning chamber 161. (Para, 0152). Matsushima also discloses an electrode section 182 is provided below the space 163, a high-frequency power supply 181 is connected to the electrode section 182 through a matching device 183 and the cleaning chamber 161 is grounded. (Para, 0153). Matsushima discloses the dry cleaning apparatus 102 is a dual-frequency plasma processing apparatus having an inductively-coupled electrode at the top and a capacitively-coupled electrode at the bottom so that the electrode section 182 and the cleaning chamber 161 constitute a capacitively-coupled electrode while the coil 165 constitutes an inductively-coupled electrode. (Para, 0154). Matsushima discloses the high-frequency power supply 181 can be configured to have a frequency of approximately 100 kHz to 100 MHz, and to apply a high-frequency power of approximately 0.15-1 kW to the electrode section 182. (Para, 0155). Moreover, Matsushima discloses the high-frequency power supply 180 can be configured to have a frequency of approximately 100 kHz to 100 MHz, and to apply a high-frequency power of approximately 1-5 kW to the coil 165. (Para, 0156). Matsushima discloses the matching device 166, 183 includes a tuning circuit. The matching device 166, 183 can control the plasma P by controlling the reflection wave using the tuning circuit. (Para, 0157). Matsushima discloses in this dry cleaning apparatus 102, the electrode section 182, the cleaning chamber 161, the high-frequency power supply 181, the high-frequency power supply 180, the coil 165, the gas supply section 168 and the like constitute a third supply section for supplying a plasma product produced from a reducing gas to the surface of the to-be-cleaned object W. (Para, 0157). These disclosures teach and/or suggest the limitations of claim 24, ‘An apparatus for reducing ruthenium (RU) oxides on an extreme ultraviolet (EUV) photomask, comprising: …and subsequently allow the reducing agent gas, the carrier gas, and the plasma to flow into the EUV photomask processing chamber to interact with the EUV photomask when present to reduce RU oxides on a RU capping layer on the EUV photomask.’ Moreover, these disclosures teach and/or suggest the limitiaotn of claim 27, ‘An apparatus for reducing ruthenium (RU) oxides on an extreme ultraviolet (EUV) photomask, comprising: …and subsequently allow the reducing agent gas and the carrier gas to flow onto a top surface of the EUV photomask to reduce RU oxides on a RU capping layer on the EUV photomask.’
Matsushima then discloses a method of operation of the dry cleaning apparatus 102. (Para, 0173). Matsushima discloses the gate 173 of the gate valve 177 is opened by the gate opening mechanism and then by a transport device, not shown, the to-be-cleaned object W is carried from the carry-in/out port 179 into the cleaning chamber 161 and is mounted on the electrode section 182 and held by the holding mechanism incorporated in the electrode section 182. (Para, 0174-0175). Matsushima discloses the gate 173 of the gate valve 177 is closed by the gate opening mechanism and then the cleaning chamber 161 is evacuated by the evacuation section 169. (Para, 0177-0178). This disclosure teaches and/or suggests the limitation of claim 10. Matsushima discloses next the processing gas G is supplied from the supply section 168 through the processing gas introduction port 162 into the space 163 and this processing gas G can be a reducing gas such as ammonia gas, hydrogen gas, a mixed gas of ammonia gas and nitrogen gas, or a mixed gas of hydrogen gas and nitrogen gas. (Para, 0179-0181). This disclosure teaches and/or suggest the limitation of claim 1, ‘A method for reducing ruthenium oxides on an extreme ultraviolet (EUV) photomask, comprising: …flowing a reducing agent gas into an EUV photomask processing chamber…’ and the limitation of claims 6-7. This disclosure also teaches and/or suggests the limitation of claim 9, ‘A method for reducing ruthenium oxides on an extreme ultraviolet (EUV) photomask, comprising: …flowing gases…into an EUV photomask processing chamber…’ and the limitation of claim 12. Moreover, this disclosure teaches and/or suggests the limitation of claim 17, ‘ A method for reducing ruthenium oxides on an extreme ultraviolet (EUV) photomask, comprising: flowing a reducing agent gas and a carrier gas into…an EUV photomask processing chamber…’ and the limitation of claim 21.
Matsushima discloses next, a high-frequency power having a frequency of approximately 100 kHz to 100 MHz is applied to the coil 165 by the high-frequency power supply 180 and then a high-frequency power having a frequency of approximately 100 kHz to 100 MHz is applied to the electrode section 182 by the high-frequency power supply 181. (Para, 0182). Matsushima discloses preferably, the high-frequency powers applied by the high-frequency power supply 180 and the high-frequency power supply 181 are equal in frequency, such as the frequency of the high-frequency power applied by the high-frequency power supply 180 and the high-frequency power supply 181 can be set to 13.56 MHz. (Para, 0182). This disclosure teaches and/or suggest the limitation of claims 13 and 22. Matsushima discloses the high-frequency power supply 180 can be configured to apply a high-frequency power of approximately 3 kW and the high-frequency power supply 181 can be configured to apply a high-frequency power of approximately 1 kW. (Para, 0183).
Matsushima explains the electrode section 182 and the cleaning chamber 161 constitute a capacitively-coupled electrode; therefore, electric discharge occurs between the electrode section 182 and the cleaning chamber 161. (Para, 0184). Matsushima discloses the coil 165 constitutes an inductively-coupled electrode; therefore, a high-frequency power is introduced from the coil 165 through the dielectric window 164 into the cleaning chamber 161 and a plasma P is generated in the space 163 by the electric discharge occurring between the electrode section 182 and the cleaning chamber 161 and the high-frequency power introduced into the cleaning chamber 161. (Para, 0184). Matsushima discloses the generated plasma P excites and activates the processing gas G and produces a plasma product 305 such as neutral active species, ions, and electrons. (Para, 0184). Matsushima discloses the produced plasma product 305 falls down in the space 163 to the surface of the to-be-cleaned object W and performs dry cleaning, with the plasma P being controlled by controlling the reflection wave using the tuning circuit incorporated in the matching device 166, 183. (Para, 0185). These disclosures teach and/or suggest the limitation of claim 9, ‘A method for reducing ruthenium oxide on an extreme ultraviolet (EUV) photomask, comprising: …wherein a plasma is formed above the EUV photomask to generate a self-bias on the EUV photomask and wherein the gases in the EUV photomask processing chamber react with a ruthenium (Ru) oxide layer on a Ru capping layer to reduce the Ru oxide layer to Ru metal.’ These disclosures also teach and/or suggest the limitation of claim 17, ‘ A method for reducing ruthenium oxides on an extreme ultraviolet (EUV) photomask, comprising: …generating a plasma above the EUV photomask… using an RF power source; and flowing the reducing agent gas and the carrier gas into the plasma and onto a top surface of the EUV photomask, wherein the reducing agent gas reacts with a ruthenium (Ru) oxide layer on a Ru capping layer to reduce the Ru oxide layer to Ru metal.’
Still, the disclosures and illustrations of Matsushima as discussed above fail to teach and/or suggest the limitations of claim 1, ‘A method for reducing ruthenium oxides on an extreme ultraviolet (EUV) photomask, comprising: heating the EUV photomask with a ruthenium (Ru) capping layer with a top surface which has a Ru oxide layer to a temperature of approximately 100 degrees Celsius to approximately a thermal budget of the EUV photomask …and pressurizing the EUV photomask processing chamber to a process pressure to increase a reducing reaction between the reducing agent gas and the Ru oxide layer on the Ru capping layer. However, the disclosures of Matsushima in view of the disclosures of Spurlin provide such teachings.
Spurlin is also directed to plasma apparatuses for semiconductor processing and methods of using the apparatuses. Spurlin illustrates an exemplary flow diagram illustrating a method of treating a substrate with a metal seed layer or semi-noble metal layer for plating metal on the substrate. (Para, 0049; Fig.2B). Spurlin discloses the process can begin with step 205b where a metal seed layer or semi-noble metal layer is deposited on the substrate and the metal seed layer can be a copper seed layer and the semi-noble metal layer can be a cobalt layer or ruthenium layer. (Para, 0049). Spurlin discloses the process 200b can continue with step 210b where the substrate is transferred to a chamber or apparatus having a substantially reduced pressure or vacuum environment. (Para, 0050). Spurlin discloses, a reduced pressure or vacuum environment can have a pressure between about 0.1 Torr and about 5 Torr and the chamber or apparatus can include a reducing gas species, such as hydrogen (H2), ammonia (NH3), carbon monoxide (CO), diborane (B2H6), sulfite compounds, carbon and/or hydrocarbons, phosphites, and/or hydrazine (N2H4). (Para, 0050). Spurlin explains that during the transfer in step 210b, the substrate may be exposed to ambient conditions that can cause the surface of the metal seed layer or semi-noble metal layer to oxidize. Thus, at least a portion of the metal may be converted to an oxidized metal. (Para, 0050). Spurlin then discloses, while the substrate is in the reduced or vacuum environment, a remote plasma may be formed of the reducing gas species and the remote plasma may include radicals of the reducing gas species, such as, for example, H*, NH2*, or N2H3*. (Para, 0051). Spurlin discloses the radicals of the reducing gas species react with the metal oxide surface to generate a pure metallic surface. (Para, 0052). Spurlin discloses the substrate is exposed to the remote plasma to reduce oxides of the metal seed layer or the semi-noble metal layer and the remote plasma may include ions and other charged species of the reducing gas species. (Para, 0053). Spurlin discloses the ions or charged species may react with the metal oxide to reduce the metal oxide and in some implementations, the ions or charged species in the remote plasma can include, for example, H+, NH2+, NH3+, and H−. (Para, 0053). Spurlin explains the ions or charged species may be advantageous for reducing oxide on metal seed layers and semi-noble metal layers depending on a thickness and nature of the oxide layers, which can form on copper, cobalt, ruthenium, palladium, rhodium, iridium, osmium, nickel, gold, silver, aluminum, tungsten, and alloys thereof. (Para, 0053). The disclosures of Matsushima as discussed above in view of these disclosures of Spurlin teach and/or suggest the limitation of claim 1, ‘A method for reducing ruthenium oxides on an extreme ultraviolet (EUV) photomask, comprising: …pressurizing the EUV photomask processing chamber to a process pressure to increase a reducing reaction between the reducing agent gas and the Ru oxide layer on the Ru capping layer.’ The disclosures of Matsushima in view of these disclosures of Spurlin teach and/or suggest the limitation of claims 2-4. Moreover, the disclosures of Matsushima as discussed above in view of these disclosures of Spurlin teach and/or suggest the limitation of claim 9, ‘ A method for reducing ruthenium oxides on an extreme ultraviolet (EUV) photomask, comprising: …generating a plasma in the remote plasma generator…and flowing gases from the remote plasma generator into an EUV photomask processing chamber, wherein a remote plasma is formed above the EUV photomask…’ and the limitation of claims 11 and 14.
Spurlin discloses the reducing gas species can include at least one of H2, NH3, CO, carbon and/or hydrocarbons, B2H6, sulfite compounds, phosphites, and N2H4. (Para, 0058). Spurlin discloses the reducing gas species can be combined with mixing gas species, such as relatively inert gas species such as nitrogen (N2), helium (He), neon (Ne), krypton (Kr), xenon (Xe), radon (Rn), and argon (Ar). (Para, 0058). Spurlin discloses the flow rate of the reducing gas species can vary depending on the size of the substrate for processing. (Para, 0058). Spurlin discloses the flow rate of the reducing gas species can be between about 10 standard cubic centimeter per minute (sccm) and about 100,000 sccm for processing a single 450 mm substrate. (Para, 0058). Spurlin discloses the flow rate of the reducing gas species can be between about 500 sccm and about 30,000 sccm for processing a single 300 mm substrate species. (Para, 0058). The disclosures Matsushima in view of these disclosures of Spurlin teach and/or suggest the limitation of claim 5.
Spurlin discloses processing conditions such as temperature and pressure in the reducing chamber can also be controlled to permit conversion of the metal oxide to metal in the form of a film integrated with the metal seed layer or semi-noble metal layer. (Para, 0059). Spurlin discloses in some embodiments, the temperature of the reducing chamber can be relatively high to permit the dissociation of reducing gas species into radicals. (Para, 0059). Spurlin discloses, the reducing chamber can be anywhere between about 10C and about 500C, such as between about 50C and about 250C. (Para, 0059). Spurlin explains, higher temperatures may be used to speed up metal oxide reduction reactions and shorten the duration of exposure to the reducing gas atmosphere (e.g., plasma treatment). (Para, 0059). Spurlin discloses in some embodiments, the reducing chamber can have a relatively low pressure to substantially remove any oxygen from the reducing gas atmosphere, as minimizing the presence of oxygen in the atmosphere can reduce the effects of reoxidation such as by pumping down to a vacuum environment or a reduced pressure of between about 0.1 Torr and about 5 Torr. (Para, 0059). Spurlin discloses the increased temperature and/or the reduced temperature can also increase reflow of metal atoms in the metal seed layer or semi-noble metal layer to create a more uniform and continuous layer. (Para, 0059). Spurlin further discloses, while the reducing chamber can have a relatively high temperature to permit the dissociation of reducing gas species into radicals, the temperature of the substrate itself may be separately controlled to avoid or reduce damage to the metal seed layer. (Para, 0060). Spurlin explains that depending on the type of metal in the metal seed layer, the metal can begin to agglomerate above a threshold temperature. (Para, 0060). Spurlin discloses the temperature at which agglomeration begins to occur in copper is greater than about 100° C; however, different agglomeration temperatures may be appropriate for different metals. (Para, 0060). The disclosures of Matsushima in view of these disclosures of Spurlin teach and/or suggest the limitation of claim 1, ‘ A method for reducing ruthenium oxides on an extreme ultraviolet (EUV) photomask, comprising: heating the EUV photomask with a ruthenium (Ru) capping layer with a top surface which has a Ru oxide layer to a temperature of approximately 100 degrees Celsius to approximately a thermal budget of the EUV photomask…’ and the limitation of claims 8, 15-16 and 18-19.
Spurlin also discloses methods for treating a substrate using atmospheric plasma. (Para, 0070). Spurlin discloses treating the substrate can include removing contaminants from the surface of the substrate including removing hydrogen and/or carbon atoms from a low-k dielectric layer, removing oxide from a metal seed layer or semi-noble metal layer prior to plating metal, cleaning a copper or tungsten surface prior to deposition of a hard mask layer. (Para, 0070). Spurlin discloses instead of exposing the substrate to plasma in a reduced pressure environment or vacuum environment, the substrate is exposed to plasma under atmospheric pressure. (Para, 0070). Spurlin discloses the atmospheric pressure can be greater than about 10 Torr, greater than about 50 Torr, or between about 50 Torr and about 760 Torr. (Para, 0070). Spurlin describes each step of the process in greater detail. (Para, 0071-0085; 0090-0095). The disclosures of Matsushima in view of these disclosures of Spurlin teach and/or suggest the limitation of claim 17, ‘ A method for reducing ruthenium oxides on an extreme ultraviolet (EUV) photomask, comprising: flowing a reducing agent gas and a carrier gas into an atmospheric-pressure (AP) plasma generator…generating a plasma above the EUV photomask with the AP plasma generator…’ and the limitation of claim 20.
The disclosures of Matsushima as discussed above in view of the disclosures of Spurlin as discussed above teach and/or suggest the limitations of claim 23, ‘ An apparatus for reducing ruthenium (RU) oxides on an extreme ultraviolet (EUV) photomask, comprising: a heater electrode in the photomask support body that is configured to heat the EUV photomask when present to a range of approximately 100 degrees to approximately 150 degrees…wherein the pressure is adjustable from zero psi to 2500 psi and is adjusted, by the controller, to control a reduction rate to reduce RU oxides on a RU capping layer on the EUV photomask.’ The disclosures of Matsushima as discussed above in view of the disclosures of Spurlin as discussed above also teach and/or suggest the limitations of claim 24, ‘An apparatus for reducing ruthenium (RU) oxides on an extreme ultraviolet (EUV) photomask, comprising: …and a remote plasma generator fluidly connected to the EUV photomask processing chamber, wherein the remote plasma generator is configured to allow a reducing agent gas from the reducing agent gas supply and a carrier gas from the carrier gas supply flow through the remote plasma generator when plasma is generated in the remote plasma generator…’ and the limitation of claims 25-26. Moreover, the disclosures of Matsushima as discussed above in view of the disclosures of Spurlin as discussed above also teach and/or suggest the limitations of claim 27, ‘ An apparatus for reducing ruthenium (RU) oxides on an extreme ultraviolet (EUV) photomask, comprising: …and an atmospheric-pressure (AP) plasma generator in the EUV photomask processing chamber, wherein the AP plasma generator is configured to allow a reducing agent gas from the reducing agent gas supply and a carrier gas from the carrier gas supply to flow through the AP plasma generator when dielectric barrier discharge plasma is generated by the AP plasma generator directly above the EUV photomask…’ and the limitiaotn of claims 28-29.
It would have been obvious to one of ordinary skill in the art at the time of filing of the present application by Applicant to modify the disclosure of Matsushima in view of the disclosures of Spurlin because both are directed to dry cleaning apparatus and methods of dry cleaning metal layers to remove oxides and Spurlin also discloses methods and apparatus which will improve the efficiency of the treatment and/or cleaning process of Matsushima which provides one of ordinary skill in the art at reasonable expectation of forming contaminant free metallic surfaces and/or substrates on which a desired smecindoutor device can be fabricated.
Conclusion
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/CALEEN O SULLIVAN/Primary Examiner, Art Unit 2899