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 § 112
Applicants’ amendments to the claims have overcome the previously presented rejections under 35 U.S.C. 112(a) and thus the rejections have been withdrawn.
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.
Claim(s) 1 and 11-12 are rejected under 35 U.S.C. 103 as being unpatentable over Inoue (JP 2010018457 A – see translation included with IDS filed 11/18/2023) in view of Tao (US 20190177230 A1).
Regarding claim 1, Inoue (JP 2010018457 A) teaches an oxide sintered body comprising Zn, Ga, Sn, and O to be used as a sputtering target, wherein the target has a bulk resistance (volume resistivity) of less than 100 ohm-cm and preferably less than 5 ohm-cm, wherein the relative density of the target is preferably 95% or more and less than 100%, and wherein the target may contain gallium (Ga) in an amount of 0.2 to 0.6 in terms of a Ga/(Zn+Ga+Sn) ratio and tin (Sn) in an amount of 0.1 to 0.4 in terms of a Sn/(Zn+Ga+Sn) ratio as well as Zn in an amount of 0.3-0.7 in terms of a Zn/(Zn+Ga+Sn) ratio (para 0009-0010, 0020-0021, 0024, 0054).
Inoue fails to explicitly teach Ga in an amount of 0.15 or more and 0.25 or less in terms of a Ga/(Zn+Ga+Sn) ratio and Sn in an amount of 0.30 or more and 0.60 or less in terms of a Sn/(Zn+Sn) ratio. However, one would have expected the use of any value within the Inoue range to have yielded similar results. Absent any showing of criticality, it would be obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have used any values within 0.2 to 0.6 for the ratio of Ga/(Zn+Ga+Sn) and any values within 0.1 and 0.4 for the ratio of Sn/(Zn+Ga+Sn), including values resulting in ratios within the claimed ranges, with a reasonable expectation of success and with predictable results. Please see MPEP 2144.05 (I) for further details. For example, a target having a composition of Zn/(Zn+Ga+Sn) = 0.5, Ga/(Zn+Ga+Sn) = 0.2 (0.15 or more and 0.25 or less), and Sn/(Zn+Ga+Sn) = 0.3 would result in a ratio of Sn/(Zn+Sn) equal to 0.375 (0.30 or more and 0.60 or less) because (Zn+Ga+Sn) is equal to 1 and therefore Zn=0.5 and Sn=0.3 (Sn/(Zn+Sn) = 0.3/(0.5+0.3) = 0.375).
Inoue also teaches the bulk resistance (volume resistivity) is preferably less than 100 ohm-cm (para 0019) but fails to explicitly teach a volume resistivity of 50 ohm-cm or less. However, one would have expected the use of any value within the Inoue range to have yielded similar results. Absent any showing of criticality, it would be obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have formed a target having less than 100 ohm-cm volume resistivity, including values within the claimed range, with a reasonable expectation of success and with predictable results. Please see MPEP 2144.05 (I) for further details.
Inoue also teaches the relative density is 95% to 100% (para 0020) but fails to explicitly teach a relative density of 97% or higher. However, one would have expected the use of any value within the Inoue range to have yielded similar results. Absent any showing of criticality, it would be obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have formed a target having a relative density of 95% to 100%, including values within the claimed range, with a reasonable expectation of success and with predictable results. Please see MPEP 2144.05 (I) for further details.
Inoue fails to explicitly teach the average crystal grain size in the target is 5 micrometers or less. However, Tao (US 20190177230 A1), in the analogous art of oxide sputtering targets, teaches a sputtering target including Zn, Ga, Sn, and O preferably has an average crystal grain size of 5 micrometers or less and relative density of preferably 97% or more in order to prevent cracking of the target, which can occur due to abnormal discharge, wherein the grain size can be controlled by hot pressing and controlling sintering temperature and duration (para 0004, 0020-0021, 0037-0041, 0076, 0087-0091, 0126, 0131-0134). Inoue teaches increasing density so that abnormal discharge does not occur, where sintering may be at normal pressure or by hot isostatic pressing (para 0020, 0042, 0050). Additionally, Tao teaches that the sintering method may include hot press sintering or pressureless sintering as alternative methods (para 0037-0041, 0127-0146). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to substitute the sintering method of Inoue with the sintering method of Tao including controlling sintering temperature and duration of Inoue to control the average crystal grain size of the target to be 5 micrometers or less while achieving a high relative density of above 97% to prevent cracking and abnormal discharge of the target. See MPEP 2143(I)(B).
Regarding claim 11, the combination of Inoue and Tao teaches the sputtering target is formed by weighing and mixing a zinc oxide (ZnO) powder, tin oxide powder, and gallium oxide (Ga2O3) powder followed by hot press sintering, where the powders introduce Zn, Sn, and Ga into the mixed powder, respectively (Inoue para 0015, 0030, 0041-0042, 0054; Tao para 0127-0138).
Alternatively, or in addition, Tao teaches that the gallium powder may be Ga2O3 and the zinc powder may be ZnO (para 0151). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to substitute the zinc oxide and gallium oxide powders of Inoue with the ZnO and Ga2O3 powders of Tao because this is a substitution of known elements yielding predictable results. See MPEP 2143(I)(B).
Regarding claim 12, the combination of Inoue and Tao teaches the powder mixture is calcined at a temperature of 500 to 1200 °C before hot pressing (Inoue para 0030, 0038, 0042) but fails to explicitly teach a calcining temperature of 1000 to 1300 °C. However, one would have expected the use of any value within the Inoue range to have yielded similar results. Absent any showing of criticality, it would be obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to have used any temperature from 500 to 1200 °C, including values within the claimed range, with a reasonable expectation of success and with predictable results. Please see MPEP 2144.05 (I) for further details.
Claim(s) 13 is rejected under 35 U.S.C. 103 as being unpatentable over Inoue (JP 2010018457 A – see translation included with IDS filed 11/18/2023) in view of Tao (US 20190177230 A1), as applied to claim 11 above, and further in view of Abe (US 20070215456 A1).
Regarding claim 13, the combination of Inoue and Tao teaches tin oxide powder (Inoue para 0030, 0054) but fails to explicitly teach SnO powder. However, Abe (US 20070215456 A1), in the analogous art of sputtering targets, teaches forming a sputtering target containing gallium oxide, zinc oxide, and tin oxide, where the powders may include Ga2O3 powder, ZnO powder, and SnO powder (para 0019, 0151). Therefore, it would have been obvious to a person having ordinary skill in the art before the effective filing date of the claimed invention to substitute the tin oxide powder of Inoue with the SnO powder of Abe because this is a substitution of known elements yielding predictable results. See MPEP 2143(I)(B).
Response to Arguments
Applicant's arguments filed 4/30/2026 have been fully considered but they are not persuasive.
Applicant argues that Inoue’s objective is to provide a target having low bulk resistivity, high density, and stable sputtering characteristics and a film that is selectively etchable, while the instant application is directed to simultaneously achieving low carrier concentration and high mobility in a film produced via use of a sputtering target and therefore the criteria for evaluating the present application are fundamentally different from those in Inoue. Additionally, applicant argues that Inoue does not recognize the problem that the film composition varies depending on target composition and therefore it would not have been reasonably foreseeable that simply selecting values from Inoue’s disclosure would lead to the film properties of the instant application. These arguments are not persuasive because the claimed invention does not require a particular carrier concentration or mobility or the forming of a particular film at all. It should be noted the claims are directed to a sputtering target and a method of making the sputtering target, not a film to be deposited by the target or a method of depositing a film, and therefore even if the claims were amended to state that the target is configured to form a film having a particular carrier concentration and mobility, the claims would only require that the target is capable of forming the disclosed film. It should also be noted that all target composition ranges disclosed by Inoue would be obvious absent any showing of criticality.
Applicant argues that the numerical ranges in the present application were not selected to optimize target properties, rather they were defined to realize the desired film properties while taking into account variation between target composition and film composition and the claimed numerical ranges cannot be dismissed as mere arbitrary selection from Inoue. This argument is not persuasive because the claimed ranges do not coincide with the entire range disclosed in the specification and thus there is no evidence that the claimed ranges are critical and produce unexpected results when compared to values outside of the claimed range. Additionally, this argument is not persuasive because the claims are directed toward a sputtering target and not the film formed and thus the criticality demonstrated must be tied to the target and not the film formed.
Applicant argues Inoue does not suggest setting the lower limit of Sn/(Zn+Sn) at 0.30 for the purpose of reducing carrier concentration in the film and the present application identifies the compositional shift whereby the Sn ratio in the film becomes higher than that of the target and thus is not merely a matter of overlapping composition ranges. This argument is not persuasive because the claims are directed toward the sputtering target and the composition range disclosed by Inoue overlaps with the claimed composition range. It should be noted that the compositional shift of the target and film would depend on the method used for sputtering, and a desired film composition could be achieved using a target outside of the claimed range with a co-sputtering method. It should also be noted that the claimed range is not critical even as a “compensation-designed range” because there is no evidence that the claimed ranges produce a film with unexpected results when compared to values outside of the claimed ranges, especially because the specification discloses that a broader target composition range is suitable to achieve the desired results.
Applicant argues that Tao concerns IGZO while the present application and Inoue relate to GZTO and therefore Tao does not disclose that an average crystal grain size of 5 micrometers or less can be achieved in a system that does not contain In, especially because Tao teaches reducing average crystal grain size through a pinning effect of In-containing phases, and it would not have been obvious to apply Tao’s teaching to Inoue. This argument is not persuasive because Tao describes other methods of reducing grain size beyond the pinning effect and that the average crystal grain size can be reduced well below 5 micrometers (para 0088); therefore, one skilled in the art would have found it obvious to reduce the grain size (e.g., to less than 5 micrometers) to prevent cracking of the oxide sputtering target, especially considering that GZTO and IGZTO are similar target materials and would be expected to have similar problems with cracking.
Applicant argues that Tao does not calcine the powder before sintering and employs hot pressing at different temperature than Inoue and therefore their combination amounts to impermissible hindsight. This argument is not persuasive because Inoue describes calcination as an optional process to make it easier to increase the density and therefore it would have been obvious to use the sintering/hot pressing methods of Tao in place of the pressing/sintering methods of Inoue while still applying calcination as described by Inoue to make increasing the density to the desired value easier. Additionally, this argument is not persuasive because the combination of Inoue and Tao does not necessitate using the same exact operating conditions for sintering/pressing and one skilled in the art would find it obvious to optimize the conditions to achieve a desired grain size as described by Tao (see para 0132).
Applicant argues the desired relative density and crystal grain cannot be obtained without the specific hot pressing conditions of the instant application and the crystal grain size cannot be attained by simple substitution and it cannot be assumed that Tao’s general discussion of preventing cracking and abnormal discharge would necessarily apply to the composition system of the present application, which does not contain indium. This argument is not persuasive because the IGZTO of Tao and GZTO of Inoue are similar oxide sputtering targets and one skilled in the art would expect similar problems of cracking and abnormal discharge to occur in each target as well as oxide targets in general. Additionally, this argument is not persuasive because the substitution of Tao for Inoue includes controlling the sintering time and temperature to achieve a desired density and grain size and therefore the alleged hot pressing conditions would be determined by optimization to achieve the density and grain size. It should also be noted that the instant application does not provide sufficient evidence of critical ranges of hot pressing conditions, rather the specification describes preferable conditions and that a too high or too low temperature results in a lower density of compositional variation (see para 0025 of the instant application).
It should also be noted that the current claims allow for indium to be included in the target and therefore a target including indium, gallium, zinc, and tin, similarly to Tao, may be sufficient to meet the current claim limitations.
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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/PATRICK S OTT/Examiner, Art Unit 1794
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