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 .
Continued Examination Under 37 CFR 1.114
A request for continued examination under 37 CFR 1.114, including the fee set forth in 37 CFR 1.17(e), was filed in this application after final rejection. Since this application is eligible for continued examination under 37 CFR 1.114, and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114. Applicant's submission filed on 02/23/2026 has been entered.
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claim(s) 1-5 and 18-19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Sasaki et al (2017/0288061) in view of Watanabe et al (US 2016/0032485), Kalejs et al (US 4,430,305) and Outwater (US 2008/0245292).
Sasaki et al teaches a Fe-doped high-resistivity β-Ga.sub.2O.sub.3 single crystal is grown by, e.g., the EFG (Edge-defined Film-fed Growth) method and is then sliced and polished to a desired thickness to form a high-resistivity substrate 11 ([0054]-[0055], [0079], [0107]).
Sasaki et al does not teach a longitudinal direction is 50 mm or more and a width is at least 10 mm at any position.
Watanabe et al teaches manufacturing Ga2O3 single crystal doped with Si using a EFG crystal manufacturing apparatus and SiO2 is used as a dopant material ([0002]-[0005], [0027]-[0055]), which clearly suggests a Si dopant. Watanabe et al also teaches forming doped plate shaped Ga2O3 having a length of not less than 65 mm and a width of 52 mm ([0054]-[0070]), which clearly suggests a quadrangle external shape and a longitudinal direction of 50 mm or larger, and a width of the single crystal is at least 10 mm at any position.
It would have been obvious to one of ordinary skill in the art at the time of filing to modify Sasaki et al by forming a β-Ga.sub.2O.sub.3 single crystal having a longitudinal direction of 50 mm or larger, and a width of the single crystal is at least 10 mm at any position, as taught by Watanabe et al, to grow a crystal having a desired size suitable for device manufacturing, wherein the claimed size is within the conventionally known ranges of sizes obtainable from an EFG process.
The combination of Sasaki et al and Watanabe et al does not teach a linear recess of 5 mm or shorter.
In a method of EFG, Kalejs et al teaches the shape of the crystal is governed by the edge configuration of the upper end of the die, the outside dimensions of the die have to be appropriately designed (col 1, ln 1-67) and the die body is tapered in at least one dimension at an upper end so that the area of its cross-section at the upper end is substantially less than the area of its cross-section immediately below the upper end (col 8, ln 1-65; Fig 1, 2 and 4). Kalejs et al also teaches growing ribbons with widths as great as 7.5 cm (col 5, ln 1-67), which clearly suggests the width of a crystal in a width direction during crystal growth is at least 10 mm at any position. Overlapping ranges are prima facie obvious (MPEP 2144.05).
In an apparatus for EFG growth, Outwater teaches eliminating voids and improving crystal quality in sheet shaped ceramic products using a sloped die tip at an angle of 5 to 40° from vertical (Fig 1; Abstract; [0014]-[0033], [0068]-[0070]).
It would have been obvious to one of ordinary skill in the art at the time of filing to modify the combination of Sasaki et al and Watanabe et al by using a sloped tipped die, as taught by Kalejs et al, and optimizing the tapered angle to improve crystal quality, as taught by Outwater. ( Outwater abstract).
In regards to the “side surface has a linear recess that extends in the longitudinal direction from one end in the longitudinal direction; among cross sections taken perpendicularly to the longitudinal direction of a portion surrounded by the side surface, a cross section at a position that is distant from the other end located on a side without the recess in the longitudinal direction by 50 mm in the longitudinal direction has an external shape such that a distance Xmax that is a maximum value of distance of the recess from an ideal external shape is 5 mm or shorter in portions excluding a portion formed by an intersection line of the cross section and a facet,” the combination of Sasaki et al, Watanabe et al, Kalejs et al and Outwater teaches a similar method of doping Ga2O3 with Fe using EFG having a sloped die, as applicant; therefore, the linear recess having a shape of 5 mm or shorter would be expected from a crystal having improved quality. Similar methods would be expected to produce similar results.
In regards to the impurity concentration of the single crystal ingot increases toward as outer periphery, the combination of Sasaki et al, Watanabe et al, Kalejs et al and Outwater teaches a similar method of doping Ga2O3 with Fe using EFG having a sloped die, as applicant; therefore, the impurity concentration of the single crystal ingot would be expected to increases toward as outer periphery because applicant teaches concentration of the dopant oxide in melts 20 located between the crystal growth interface 220 and the top surface 120 of the crystal growth die 12 increases as the position goes away from the slit 121 (See paragraph [0135] of the published application).
Referring to claim 2, the combination of Sasaki et al, Watanabe et al, Kalejs et al and Outwater teaches a width of greater than 50 mm ([0070]). Furthermore, changes in size and shape are prima facie obvious (MPEP 2144.04), and larger crystals would have been obvious to one of ordinary skill in the art at the time of filing.
Referring to claim 3 and 5, as discussed above, the combination of Sasaki et al, Watanabe et al, Kalejs et al and Outwater teaches a similar method of doping Ga2O3 with Fe and SiO2 using EFG having a sloped die; therefore, the claimed product limitation would be expected.
Referring to claim 4 and 18-19, the combination of Sasaki et al, Watanabe et al, Kalejs et al and Outwater teaches Ga2O3 doped with Fe and Si (Sasaki ([0054]-[0055], [0079], [0107]; Watanabe [0002]-[0005], [0055]).
Response to Arguments
Applicant’s arguments with respect to claim(s) 1-5 and 18-19 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.
Applicant's arguments filed 02/23/2026 have been fully considered but they are not persuasive.
Applicant’s argument that the prior art does not teach the impurity concentration increases toward an outer periphery of the single crystal ingot is noted but not found persuasive. As discussed above, the prior art does not explicitly teach this feature, however this feature would be expected for a Fe-doped Ga2O3 produced using a EFG method because applicant teaches concentration of the dopant oxide in melts 20 located between the crystal growth interface 220 and the top surface 120 of the crystal growth die 12 increases as the position goes away from the slit 121 (See paragraph [0135] of the published application). A similar method (EFG) would be expected to produce similar results/effects; therefore, the Fe dopant would be expected to increase away from the slit in an EFG process, thereby producing a crystal with increased Fe concentration toward an outer periphery.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Kawasaki et al (US 2021/0017668) teaches a EFG 57 mm x 112 mm Sn doped Ga2O3 (Abstract; [0051]).
Watanabe et al (US 2017/0152610) teaches Ga2O3 doped with Mg, Si, Fe, Cu, or Nb ([0057]).
Sasaki (US 2016/0017512) teaches using pure Fe or Fe oxide as a raw material of Fe to be added to the Ga2O3 powder.
JP 2011190127 teaches producing a gallium oxide single crystal by EFG and using an oxide dopant, such as Fe3O4 (pgs 3-4 of Computer translation).
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MATTHEW J. SONG
Examiner
Art Unit 1714
/MATTHEW J SONG/ Primary Examiner, Art Unit 1714