DETAILED ACTION
Notice of Pre-AIA or AIA Status
1. The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
Election/Restrictions
2. Applicant’s election of Species A in the reply filed on 05-29-2026 is acknowledged. Because applicant did not distinctly and specifically point out the supposed errors in the restriction requirement, the election has been treated as an election without traverse (MPEP § 818.01(a)).
Claim Objections
3. Claim 4 is objected to because of the following informalities:
In claim 4, the phrase “the reactor” (occurs 2 times) lacks proper antecedent basis. The examiner suggests replacing “the reactor” with --the MOCVD reactor – in order to provide proper antecedent basis . Appropriate correction is required.
Claim Rejections - 35 USC § 112
4. The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
5. Claims 10-11 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
Claim 10 depends on claim 1. In claim 1, applicants fail to disclose the step of doping an etched surface of the Ga2O3 sample. In claim 11, the phrase “increasing the surface concentration of dopants underneath an etched surface of the Ga2O3 sample” because it is unclear whether the step of doping an etched surface of the Ga2O3 sample is required or not.
Claim 11 depends on claim 1. In claim 1, applicants fail to disclose the present of β-(AlxGa1-x)2O3 layer/material. The phrase “wherein β-(AlxGa1-x)2O3 comprises an etching stop layer on the Ga2O3 sample” in claim is indefinite because applicants fail to disclose the present of β-(AlxGa1-x)2O3 in claim 1. The term “wherein” is used to further define the previous limitation recited in the claim.
Claim Rejections - 35 USC § 103
6. 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.
7. 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.
8. Claims 1-3, 6, 8-11 are rejected under 35 U.S.C. 103 as being unpatentable over Hatch eta l. (“Plasma Enhanced atomic layer deposition and atomic layer etching of gallium oxide using trimethylgallium”, Research Article; June 22, 2022 via https://pubs.aip.org/avs/jva/article-abstract/40/4/042603/2846288/Plasma-enhanced-atomic-layer-deposition-and-atomic?redirectedFrom=fulltext ,herein after refer as Hatch) in view of Comstock et al. (“Atomic Layer Deposition of Ga2O3 Films Using Trimethylgallium and Ozone”, ACS Publications, American Chemical Society, Chemistry of Materials), herein after refers as Comstock, and further in view of Kalarickal et al. (“Planar and three-dimensional damage-free etching of β-Ga2O3 using atomic gallium flux”, Research Article; Applied Physics Letters, September 22, 2021), herein after refer as Kalarickal.
Note:
As to claim 1, Hatch discloses for damage-free etching of Ga2O3, the method comprising:
loading a Ga2O3 sample in a metal organic chemical vapor deposition (MOCVD) reactor (page 1);
heating the Ga2O3 sample (page 1; substrate temperature at 300 ° C);
contacting the Ga2O3 sample with a metal organic precursor (i.e. trimethylgallium (TMG)) 2O3 sample
As to claim 1, Hatch fails to disclose the metal organic precursor yield gallium and hydrocarbon components when contacts with Ga2O3 in order to etch Ga2O3 with gallium. However, Hatch clearly teaches to contact trimethyl gallium with Ga2O3 to etch Ga2O3 sample. Comstock discloses contact the Ga2O3 sample with trimethyl gallium to yield gallium and hydrocarbon components because the trimethyl gallium undergoes thermal decomposition when heating (pages 4011-4104; 4015). Kalarickal discloses etching Ga2O3 using gallium flux with high etch rate and high aspect ratio (See abstract, pages 123503-1 to pages 123503-5). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Hatch in view of Comstock and Kalarickal by contact the Ga2O3 with trimethyl gallium yield gallium and hydrocarbon, thereby etching the Ga2O3 with the gallium because it results in high etch rate and high aspect ratio for etching Ga2O3. Further, equivalent and substitution of one for the other would produce an expected result (See MPEP 2143(I)(B)).
As to claim 2, Hatch fails to disclose heating the Ga2O3 sample comprises heating at least 600 °C. However, Hatch clearly teaches to heat the Ga2O3 sample. Kalarickal teaches to heat the Ga2O3 sample to 700 ° or 800 °C (page 123503-2, within applicant’s range of “at least 600 °C”). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Hatch in view of Comstock and Kalarickal by heating the Ga2O3 sample to at least 600 °C because in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists (See MPEP 2144.05(I)).
As to claim 3, Hatch teaches the organic gallium precursor comprises trimethyl gallium (page 1). Comstock also discloses the organic gallium precursor comprises trimethyl gallium (abstract).
As to claim 6, Hatch discloses the metal organic precursor (i.e. trimethyl gallium) is provided to the MOCVD reactor at a predetermined flow rate (page 1). Comstock also discloses the metal organic precursor (i.e. trimethyl gallium) is provided to the MOCVD reactor at a predetermined flow rate (pages 4011-4017). Note: the examiner interprets any reactor that uses metal organic gas (or vapor) to deposit a material in the reactor is a metal organic chemical vapor deposition (MOCVD) reactor.
As to claim 8, Hatch fails to disclose the Ga2O3 sample comprises β-phase (monoclinic) Ga2O3, α-phase (corundum) Ga2O3, κ-phase (orthorhombic) Ga2O3, γ-phase (defective spinel) Ga2O3, or any combination thereof. However, Hatch clearly teaches to use Ga2O3 sample. Kalarickal discloses Ga2O3 comprises β-phase (monoclinic) Ga2O3 (See abstract). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Hatch in view of Comstock and Kalarickal by using β-phase (monoclinic) Ga2O3 because equivalent and substitution of one for the other would produce an expected result (See MPEP 2143(I)(B)).
As to claim 9, Hatch discloses etching Ga2O3 sample comprises fabricating three-dimension structures on Ga2O3 (page 1; Note: all structures must be three-dimension because all structures must have width, length and depth). As to claim 9, Hatch fails to disclose the three-dimension structures on Ga2O3 comprises fins, trenches, nanopillars with vertical sidewalls, or any combination thereof. Kalarickal discloses the three-dimension structures on Ga2O3 comprises fins, trenches, nanopillars with vertical sidewalls, or any combination thereof (page 123503-2 col. 1). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Hatch in view of Comstock and Kalarickal by having the three-dimension structures on Ga2O3 comprises fins, trenches, nanopillars with vertical sidewalls, or any combination thereof because equivalent and substitution of one for the other would produce an expected result (See MPEP 2143(I)(B)).
As to claim 10, Hatch fails to disclose increasing the surface concentration of dopants underneath an etched surface of the Ga2O3 sample. Kalarickal teaches increasing the surface concentration of dopants underneath an etched surface of the Ga2O3 sample (page 123503-5). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Hatch in view of Comstock and Kalarickal by discloses increasing the surface concentration of dopants underneath an etched surface of the Ga2O3 sample because increasing surface concentration is useful in some applications like contact regrowth or field emission (pages 123503-5, col. 2).
As to claim 11, Hatch fails to disclose wherein β-(AlXGa1-X)2O3 comprises an etching stop layer on the Ga2O3 sample, wherein X is a number between 0 and 1. It is noted that when X = 0, the formula β-(AlXGa1-X)2O3 become β-Ga2O3 since the number of aluminum atom is zero. Kalarickal teaches β-Ga2O3 can be an etching stop layer on the Ga2O3 sample, wherein X = 0 because the etching process is stopped at the exposed surface of β-Ga2O3 (See Fig 3; Note β-Ga2O3 is read on applicant’s limitation AlXGa1-X)2O3 when x = 0). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Hatch in view of Comstock and Kalarickal by having β-(AlXGa1-X)2O3 comprises an etching stop layer on the Ga2O3 sample, wherein X = 0 because equivalent and substitution of one for the other would produce an expected result (See MPEP 2143(I)(B)).
9. Claim 4 is rejected under 35 U.S.C. 103 as being unpatentable over Hatch et al. (“Plasma Enhanced atomic layer deposition and atomic layer etching of gallium oxide using trimethylgallium”, Research Article; June 22, 2022 via https://pubs.aip.org/avs/jva/article-abstract/40/4/042603/2846288/Plasma-enhanced-atomic-layer-deposition-and-atomic?redirectedFrom=fulltext ,herein after refer as Hatch) in view of Comstock et al. (“Atomic Layer Deposition of Ga2O3 Films Using Trimethylgallium and Ozone”, ACS Publications, American Chemical Society, Chemistry of Materials), herein after refers as Comstock, and further in view of Kalarickal et al. (“Planar and three-dimensional damage-free etching of β-Ga2O3 using atomic gallium flux”, Research Article; Applied Physics Letters, September 22, 2021), herein after refer as Kalarickal as applied to claim 1 above, and further in view of Sun (CN 110556452A).
As to claim 4, Hatch, Comstock, and Kalarickal fail to disclose providing a carrier gas to the reactor to control a pressure in the reactor. Sun discloses providing a carrier gas (argon to the reactor to control a pressure in the reactor (paragraph 0009, 0027-0030). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Hatch, Comstock and Kalarickal in view of Sun by providing a carrier gas to the reactor to control a pressure in the reactor because the use of argon carrier gas is well known in the art to assist the flow of other gas into the reactor.
10. Claim 5 is rejected under 35 U.S.C. 103 as being unpatentable over Hatch eta l. (“Plasma Enhanced atomic layer deposition and atomic layer etching of gallium oxide using trimethylgallium”, Research Article; June 22, 2022 via https://pubs.aip.org/avs/jva/article-abstract/40/4/042603/2846288/Plasma-enhanced-atomic-layer-deposition-and-atomic?redirectedFrom=fulltext ,herein after refer as Hatch) in view of Comstock et al. (“Atomic Layer Deposition of Ga2O3 Films Using Trimethylgallium and Ozone”, ACS Publications, American Chemical Society, Chemistry of Materials), herein after refers as Comstock, and further in view of Kalarickal et al. (“Planar and three-dimensional damage-free etching of β-Ga2O3 using atomic gallium flux”, Research Article; Applied Physics Letters, September 22, 2021), herein after refer as Kalarickal as applied to claim 1 above, and further in view of Taniyama et al. (US 2012/0052657 A1).
As to claim 5, Hatch fails to disclose the metal organic gallium precursor undergoes pyrolysis. However, Hatch clearly teaches to heat the metal organic gallium precursor (i.e. trimethyl gallium). Comstock discloses that the metal organic gallium precursor such as trimethyl gallium (TMGa) undergoes thermal decomposition (pages 4015, 4017). Taniyama discloses trimethyl gallium (TMGa) undergoes pyrolysis by a heating process (paragraph 0089, 0092, 01145). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Hatch, Comstock and Kalarickal by having the metal organic gallium precursor undergoes pyrolysis because equivalent and substitution of one for the other would produce an expected result (See MPEP 2143(I)(B)).
11. Claim 7 is rejected under 35 U.S.C. 103 as being unpatentable over Hatch eta l. (“Plasma Enhanced atomic layer deposition and atomic layer etching of gallium oxide using trimethylgallium”, Research Article; June 22, 2022 via https://pubs.aip.org/avs/jva/article-abstract/40/4/042603/2846288/Plasma-enhanced-atomic-layer-deposition-and-atomic?redirectedFrom=fulltext ,herein after refer as Hatch) in view of Comstock et al. (“Atomic Layer Deposition of Ga2O3 Films Using Trimethylgallium and Ozone”, ACS Publications, American Chemical Society, Chemistry of Materials), herein after refers as Comstock, and further in view of Kalarickal et al. (“Planar and three-dimensional damage-free etching of β-Ga2O3 using atomic gallium flux”, Research Article; Applied Physics Letters, September 22, 2021), herein after refer as Kalarickal as applied to claim 1 above, and further in view of Su et al. (US 2011/0033966 A1).
As to claim 7, Hatch, Comstock and Kalarickal fail to disclose controlling the predetermined flow rate with a mass flow controller. However, Hatch and Comstock clearly disclose flowing trimethyl gallium precursor into the reactor. Su teaches to flow the metal organic precursor (i.e. trimethyl gallium) using a mass flow controller (paragraph 0042, 0046, 0056, 0059). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Hatch, Comstock and Kalarickal in view of Su by controlling the predetermined flow rate with a mass flow controller because it helps to measure the flow rate of the gas into the reactor.
12. Claims 12-13 are rejected under 35 U.S.C. 103 as being unpatentable over Hatch eta l. (“Plasma Enhanced atomic layer deposition and atomic layer etching of gallium oxide using trimethylgallium”, Research Article; June 22, 2022 via https://pubs.aip.org/avs/jva/article-abstract/40/4/042603/2846288/Plasma-enhanced-atomic-layer-deposition-and-atomic?redirectedFrom=fulltext ,herein after refer as Hatch) in view of Comstock et al. (“Atomic Layer Deposition of Ga2O3 Films Using Trimethylgallium and Ozone”, ACS Publications, American Chemical Society, Chemistry of Materials), herein after refers as Comstock, and further in view of Kalarickal et al. (“Planar and three-dimensional damage-free etching of β-Ga2O3 using atomic gallium flux”, Research Article; Applied Physics Letters, September 22, 2021), herein after refer as Kalarickal as applied to claim 1 above, and further in view of Hu et al. (US 11,715,774 B2).
As to claim 12, Hatch, Comstock and Kalarickal fail to disclose a gate recess in a lateral or vertical Ga2O3 transistor. As to claim 12, Kalarickal teaches the damage-free etching of Ga2O3 yields a gate recess in a lateral or vertical direction (See pages 123503-2, Fig 3). Hu discloses etching of gallium oxide yield a gate recess in a lateral or vertical Ga2O3 transistor (col. 1-col. 2, col. 3 lines 45 to col. 4 lines 30). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Hatch, Comstock and Kalarickal in view of Hu by having a gate recess in a lateral or vertical Ga2O3 transistor because equivalent and substitution of one for the other would produce an expected result (See MPEP 2143(I)(B)).
As to claim 13, Hatch, Comstock and Kalarickal fail to disclose a recess for ohmic contact in a lateral or vertical Ga2O3 transistor. As to claim 13, Kalarickal teaches the damage-free etching of Ga2O3 yields a gate recess in a lateral or vertical direction (See pages 123503-2, Fig 3). Hu discloses etching of gallium oxide yield a ohmic contacts in a lateral or vertical Ga2O3 transistor (abstract, col. 2 lines 10-30, col. 3 lines 47 to col. 4 line 16). It would have been obvious to one of ordinary skill in the art, before the effective filing date of the claimed invention, to modify Hatch, Comstock and Kalarickal in view of Hu by having a recess for ohmic contact in a lateral or vertical Ga2O3 transistor because equivalent and substitution of one for the other would produce an expected result (See MPEP 2143(I)(B)).
Conclusion
13. Any inquiry concerning this communication or earlier communications from the examiner should be directed to BINH X TRAN whose telephone number is (571)272-1469. The examiner can normally be reached Monday-Friday.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Joshua Allen can be reached at 571-270-3176. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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BINH X. TRAN
Examiner
Art Unit 1713
/BINH X TRAN/Primary Examiner, Art Unit 1713
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