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 § 112
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.
Claim(s) 7 and 8 is/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.
The term “high purity” in claim 7 is a relative term which renders the claim indefinite. The term “high purity” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. The term is not adequately defined enough for a person having ordinary skill to ascertain. It is unclear the amount of purity necessary to infringe this claim. Appropriate correction is advised.
The term “high temperature” in claim 8 is a relative term which renders the claim indefinite. The term “high temperature” is not defined by the claim, the specification does not provide a standard for ascertaining the requisite degree, and one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. The term is not adequately defined enough for a person having ordinary skill to ascertain. It is unclear the degree of temperature necessary to infringe this claim. Appropriate correction is advised.
Claim Rejections - 35 USC § 102
The following is a quotation of the appropriate paragraphs of 35 U.S.C. 102 that form the basis for the rejections under this section made in this Office action:
A person shall be entitled to a patent unless –
(a)(2) the claimed invention was described in a patent issued under section 151, or in an application for patent published or deemed published under section 122(b), in which the patent or application, as the case may be, names another inventor and was effectively filed before the effective filing date of the claimed invention.
Claim(s) 1, 2, and 5 is/are35 U.S.C. 102(a)(2) as being anticipated by in view of Song (CN107195721B).
Claim 1
Song teaches: A photodetector based on transverse Dember effect (see Abstract), comprising: a tilted single-crystal substrate (1), a tilted epitaxial layer (2), a metal electrode pair (6), metal wires (7), and a voltage signal acquisition device (V);
wherein, the tilted epitaxial layer (2) is located on an upper surface of the tilted single-crystal substrate (1); a tilt angle of the epitaxial layer is an included angle between a crystallographic axis and a surface normal of the tilted epitaxial layer (2); two metal electrodes of the metal electrode pair (6) are respectively located at two ends of an upper surface of the tilted epitaxial layer (2); each metal electrode is connected to one metal wire; the voltage signal acquisition device (V) is configured to acquire voltage signals output by the two metal wires (7); and the voltage signals are generated by means of transverse Dember effect (see Abstract) of the tilted epitaxial layer (2).
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Claim 2/1
Song teaches: The photodetector based on transverse Dember effect according to claim 1, wherein the tilt angles range from 0.1° to 45° (0 ° <θ <30 °; see content of invention para. 1).
Claim 5/1
Song teaches: The photodetector based on transverse Dember effect according to claim 1, wherein a thickness of the tilted epitaxial layer (2) is from 10 nm to 50,000 nm (50 nm- 1μm; see para. 3).
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) 3 and 4 is/are rejected under 35 U.S.C. 103 as being unpatentable over Song in view of Hori (WO 2018066173 A1).
Claim 3/1
Song teaches: The photodetector based on transverse Dember effect according to claim 1, but is silent to: wherein a material of the tilted single-crystal substrate (1) is AlN, Si3N4, or 4H-SiC.
Hori teaches a silicon carbide epitaxial substrate comprising a 4H-SiC single-crystal substrate having a main surface inclined from a plane by an off angle between 0° and 8°, and a silicon carbide epitaxial layer formed on the inclined main surface. Hori further explains that the off angle facilitates epitaxial growth by step flow growth and specifically identifies 4H-SiC as advantageous for semiconductor applications. Accordingly, the single crystal substrate taught by Hori is applicable to a Photo Luminance imaging device which is in the realm of the art of the claimed invention.
It would have been obvious to a person having ordinary skill in the art at the time the claimed invention was filed to employ Hori’s 4H-SiC single-crystal substrate as the tilted single-crystal substrate of Song’s photodetector. Such a modification would have involved a simple substitution of one known semiconductor single-crystal substrate material for another.
Claim 4/1
Song teaches: The photodetector based on transverse Dember effect according to claim 1, but does not expressly teach: wherein a material of the tilted epitaxial layer (2) is Ga2O3, GaN, AlN, BN, B4C, AlP, or 4H-SiC.
Hori teaches a silicon carbide epitaxial substrate comprising a 4H-SiC single-crystal substrate having a main surface inclined from a plane by an off angle between 0° and 8°, and a silicon carbide epitaxial layer formed on the inclined main surface. Hori further explains that the off angle facilitates epitaxial growth by step flow growth and specifically identifies 4H-SiC as advantageous for semiconductor applications. Accordingly, the single crystal substrate taught by Hori is applicable to a Photo Luminance imaging device which is in the realm of the art of the claimed invention.
It would have been obvious to a person having ordinary skill in the art at the time the claimed invention was filed to employ Hori’s 4H-SiC tilted epitaxial layer as the silicon carbide epitaxial substrate of Song’s photodetector. Such a modification would have involved a simple substitution of one known semiconductor tilted epitaxial layer material for another.
Claim(s) 6 is/are rejected under 35 U.S.C. 103 as being unpatentable over Song in view of Hu (CN 214797435 U).
Claim 6/1
Song teaches: The photodetector based on transverse Dember effect according to claim 1, wherein a material of the metal electrode pair (6) is W, Ag, Ti, Ni, or Pt (see Summary of the invention para. 10).
While Song discloses that “the distance between the metal electrodes at both ends of the heat-absorbing coating is greater than or equal to 1 mm”, Song does not expressly teach that: a thickness of the metal electrode pair is from 50 nm to 200 nm;
Hu, conversely, I directed to a semiconductor photodetector and teaches a device having metal source and drain electrodes disposed at respective ends of a semiconductor photodetection material. Hu specifically teaches that the electrodes comprise a Pt/Au composite metal, with the Pt layer having a thickness of 50 nm and the Au layer having a thickness of 50 nm. Thus, Hu teaches a metal electrode having a total thickness of 100 nm, which falls within the claimed range of 50 nm to 200 nm. Hu further teaches forming electrodes by thermal evaporation.
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It would have been obvious to a person having ordinary skill in the art at the time the claimed invention was filed to employ Hu’s disclosed electrode thickness in Song’s photodetector. Both Song and Hu are directed to semiconductor photo/thermo detectors having metal electrodes for extracting an electrical signal generated in response to incident radiation. Accordingly, a person having ordinary skill seeking to implement Song’s detector would have reasonably considered the electrode dimensions and fabrication techniques of Hu to be applicable to Song’s metal electrodes. Furthermore, a person of ordinary skill in the art would have reason to select a thickness such as 100 nm, as taught by Hu, to provide a sufficiently thick and continuous conductive electrode for reliable electrical signal extraction while avoiding unnecessary electrode thickness and associated material and fabrication cost.
Claim(s) 7 is/are rejected under 35 U.S.C. 103 as being unpatentable over Song in view of Murai (US6492593B2).
Claim 7/1
Song as modifies by Song teaches: The photodetector based on transverse Dember effect according to claim 1, but does not expressly disclose: wherein the metal wire is a high-purity metal wire.
Murai considerably teaches a gold wire provided for electrically connecting an external lead to an electrode of a semiconductor element. In particular, Murai teaches bonding a gold wire directly to an electrode of the semiconductor element and subsequently bonding the gold wire to an external lead to complete the electrical connection. Murai further teaches that the gold starting material is preferably high purity gold having a purity of at least 99.99 wt.%, more preferably at least 99.995 wt.% and even more preferably at least 99.999 wt.% (see detailed description para. 3).
It would have been obvious to a person having ordinary skill in the art the time the claimed invention was filed to employ Murai’s high purity gold wire as the metal wire connected to Song’s metal electrodes. Both Song and Murai employ conductive wires connected to electrodes of semiconductor devices to establish an electrical connection, and Song specifically relies on such wires to transmit the voltage signal generated by their invention to the voltage signal acquisition device. Thus, Murai provides a known and suitable implementation of the conductive wire connection taught by Song. Moreover, Murai’s teaching of high purity gold is particularly applicable where the wire is used to electrically connect a semiconductor electrode, as in Song.
Claim(s) 8 and 9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Song in view of Opape (JP 2023523691 A) and Hirose (US 20220307735 A1).
Claim 8
Song teaches: A method for preparing a transverse Dember effect-based photodetector (see Abstract), comprising:
growing (epitaxial layer is grown, see content of invention para. 1) a tilted epitaxial layer (2) on a tilted single-crystal substrate (1), wherein there is an included angle between a crystallographic axis and a normal of the tilted epitaxial layer (2), and tilt angles of the tilted single-crystal substrate (1) and the tilted epitaxial layer (2) are close (0 ° <θ <30 °; see content of invention para. 1); preparing a patterned metal electrode pair (6) on an upper surface of the tilted epitaxial layer (2), wherein two metal electrodes of the patterned metal electrode pair (6) are respectively located at two ends of the upper surface of the tilted epitaxial layer (2); and
connecting each metal electrode to one end of a metal wire and connecting the other end of the metal wire to a voltage signal acquisition device (V).
Song however does not expressly teach: I) growing the tilted epitaxial layer on the tilted single-crystal substrate using a vapor deposition method; II) connecting each metal electrode to one end of a metal wire via high temperature silver glue
As for limitation I, Opape considerably teaches that epitaxial growth is a known deposition technique for growing one crystalline material on another crystalline material. Opape further expressly identifies vapor phase deposition techniques, including electron beam physical vapor deposition, plasma enhanced chemical vapor deposition, and molecular beam epitaxy, as techniques for epitaxial growth (see background para. 6).
It would have been obvious to a person having ordinary skill in the art at the time the claimed invention was filed to employ a known vapor deposition epitaxial growth technique, as taught by Opape, when forming the epitaxial layer of Song’s invention. Such a modification would merely be a known technique for its established purpose of forming an epitaxial layer on a crystalline substrate, with reasonable expectation of success.
As for limitation II, Hirose teaches an electrocaloric element having external electrodes and further teaches that a wire for voltage application is bonded to both ends of the external electrodes using Ag paste. Hirose applies the voltage through the bonded wires and measures the resulting temperature change of the element (see para. 0065). Thus, Hirose demonstrates the known use of Ag paste for electrically connecting voltage application wires to electrodes in an electrical device in which a response is measured.
It would have been obvious to a person having ordinary skill in the art at the time the claimed invention was filed to employ Hirose’s Ag paste electrical connection technique in Song’s photodetector to connect each metal electrode to a respective metal wire. Such a modification would have merely involved using a known conductive bonding material to establish an electrical connection between an electrode and a wire, particularly where the wire is used to transmit an electrical signal to or from the electrode.
Claim(s) 9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Song as modified by Opape and Hirose in view of Ellison (US8492772B2).
Claim 9/8
Song as modified by Opape and Hirose teaches: The method for preparing a transverse Dember effect-based photo detector according to claim 8, growing a tilted epitaxial layer (2) on a tilted single-crystal substrate (1), but wherein the growing a tilted epitaxial layer on a tilted single-crystal substrate using a vapor deposition method specifically comprises: growing a tilted single-crystal epitaxial film on the tilted single-crystal substrate (1), taking the tilted single-crystal epitaxial film as the tilted epitaxial layer (2), wherein a thickness of the tilted epitaxial layer (2) is from 10 nm to 50,000 nm (50 nm- 1μm; see para. 3; Song); and the tilt angle of the epitaxial layer ranges from 0.1° to 45° (0 ° <θ <30 °; see content of invention para. 1; Song).
Song as modified by Opape and Hirose however is silent to: using a chemical vapor deposition method to grow a tilted epitaxial layer on a tilted single-crystal substrate;
Ellison conversely teaches a method comprising forming an epitaxial layer on a tilted off axis single crystal substrate using chemical vapor deposition (see para. 0053). For example, Ellson teaches epitaxial growth on an off axis single crystal substrate and expressly states that the epitaxial growth is performed using chemical vapor deposition (CVD).
It would have been obvious to a person having ordinary skill in the art before the claimed invention was filed to employ the CVD epitaxial growth technique of Ellison when forming the epitaxial layer of Song. Doing so would have merely involved using a known epitaxial growth technique for its established purpose of forming a crystalline epitaxial layer on a single crystal substrate, including an off axis substrate, with reasonable expectation of success.
Claim(s) 10 is/are rejected under 35 U.S.C. 103 as being unpatentable over Song as modified by Opape and Hirose in view of Cheng (CN 110129732 A) and Song2 (CN 109585326 B).
Claim 10/8
Song as modified by Opape and Hirose teaches: The method for preparing a transverse Dember effect-based photodetector according to claim 8, wherein a patterned metal electrode pair (6) is prepared on an upper surface of the tilted epitaxial layer (2);
Song as modified by Opape and Hirose is silent to:
I) placing the tilted single-crystal substrate of the tilted epitaxial layer (2) for vacuumization, and II) sputtering the patterned metal electrode pair on the upper surface of the tilted epitaxial layer in combination with a mask plate.
As for limitation I, Cheng teaches the claimed preparatory placement of a semiconductor substrate into a radio frequency magnetron sputtering vacuum chamber. Cheng specifically describes a method for preparing a film in which a single crystal silicon substrate is placed on a sample stage within a radio frequency magnetron sputtering vacuum chamber, after which a target is placed at the target position of the same radio frequency magnetron sputtering vacuum chamber. Cheng demonstrates that placing a single crystal semiconductor substrate within a radio frequency magnetron sputtering vacuum chamber is a known and routine step in preparing a substrate for subsequent sputtering.
It would have been obvious to a person having ordinary skill in the art at the time the claimed invention was filed to place Song’s substrate having the tilted epitaxial layer into a radio frequency magnetron sputtering vacuum system. A person of ordinary skill would recognize that this technique of vacumization is a conventional prerequisite for radio frequency magnetron sputtering and provides a controlled environment.
As for limitation II, Song2 teaches forming metal electrodes on the surface of a gallium nitride epitaxial wafer using a shadow mask plate in combination with electrode sputtering. IN particular, Song2 describes an epitaxial wafer comprising a substrate and gallium nitride epitaxial layers and teaches using a shadow mask plate for electrode evaporation or sputtering. The shadow mask plate includes a plurality of electrode deposition through holes, and Song2 explains that the shadow mask plate is placed on the epitaxial wafer surface such that metal deposited through the electrode deposition through holes forms metal electrodes on the epitaxial wafer surface. Song2 further expressly teaches that the electrode may be formed by sputtering.
It would have been obvious to a person having ordinary skill in the art at the time the claimed invention was filed to employ Song2’s shadow mask sputtering technique to form the patterned metal electrodes of Song’s photodetector on the upper surface of Song’s device. On the upper surface of Song’s tilted epitaxial layer. This modification would have been motivated by the known advantages of simplifying electrode patterning and deposition and would have been expected to produce the predictable result of selectively depositing metal through the mask openings to form the desired electrodes.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to AHMED F SECK whose telephone number is (571)272-4638. The examiner can normally be reached Monday - Friday 7:30 am - 4:30 pm.
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/AHMED F SECK/Examiner, Art Unit 2834 /CHRISTOPHER M KOEHLER/Supervisory Patent Examiner, Art Unit 2834
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