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 .
Specification
The objections to the specification are withdrawn in view of applicants’ amendments to the disclosure.
Claim Objections
The objections to claims 1 and 4 are withdrawn in view of applicants’ claim amendments.
Claim Rejections - 35 USC § 112
The 35 U.S.C. 112(b) rejection of claims 1-13 and 35 U.S.C. 112(d) rejection of claim 10 are withdrawn in view of applicants’ claim amendments.
Claim Rejections - 35 USC § 103
The text of those sections of Title 35, U.S. Code not included in this action can be found in a prior Office action.
Claims 1-9 and 12-13 is/are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent Appl. Publ. No. 2019/0221705 to Schulte, et al. (hereinafter “Schulte”) in view of a publication to Allen, et al. entitled “Characterization of surface faceting on (110)GaAs/GaAs grown by molecular beam epitaxy,” Journal of Crystal Growth, Vol. 87, pp. 193-200, (1988) (“Allen”).
Regarding claim 1, Schulte teaches a method (see the Abstract, Figs. 1-10, and entire reference which teach a method of growing Group III-V materials by hydride vapor phase epitaxy (HVPE)) comprising:
providing a GaAs substrate having a lattice orientation offset 3° towards (111) (See at least Figs. 4 & 7, ¶[0021], ¶[0051]-[0052], and ¶[0061]-[0064] which teach providing a GaAs(100) substrate (104) which is miscut 4°, 6°, or 9° towards the (111)B direction. In this case the 4° miscut substrate is sufficiently close to 3° that it would be reasonably expected to yield the same properties. Alternatively, see infra with respect to the teachings of Allen which teaches the use of a miscut GaAs(110) substrate); and
depositing one or more lattice-matched semiconducting materials on the GaAs substrate via hydroxide phase vapor epitaxy (HVPE) (see Figs. 1-3 and ¶¶[0033]-[0044] as well as elsewhere throughout the entire reference which teach deposition of a lattice-matched Group III-V semiconductor layer (110) such as GaAs onto the substrate (104)).
Schulte does not teach that the GaAs substrate has a lattice orientation of (110). However, in the Introduction section at pp. 193-94 Allen teaches that growth on the GaAs(110) surface provides more efficient ionization impact behavior for electrons and can be utilized to fabricate a p-n junction diode polarizer/modulator for use in integrated optics. In Figs. 1-5 and the Experimental section at pp. 194-96 Allen further teaches that growth on nominal GaAs(110) surfaces (e.g., with no miscut) tends to result in the initiation and propagation of facets rather than a smooth surface. Then in Figs. 6-8 and the Discussion section at pp. 198-99 Allen teaches that faceting during growth on the GaAs(110) surface may be suppressed by angling the substrate by up to 6° towards the (111) surface such that only Ga-rich or As-rich ledges are present on the surface. By utilizing a GaAs(110) substrate with up to a 6° miscut in the (111) direction it is possible to produce a higher quality epitaxial layer which is facet-free with predictable doping levels, excellent room temperature mobility, and strong exciton luminescence. Thus, a person of ordinary skill in the art prior to the effective filing date of the invention would look to the teachings of Allen and would be motivated to utilize a vicinal GaAs(110) substrate with a miscut of up to 6° towards (111) as the substrate in the HVPE growth method of Schulte in order to utilize the higher growth rates of HVPE to produce higher quality optoelectronic devices with improved electronic and optical properties. The combination of prior art elements according to known methods to yield predictable results has been held to support a prima facie determination of obviousness. All the claimed elements are known in the prior art and one skilled in the art could combine the elements as claimed by known methods with no change in their respective functions, with the combination yielding nothing more than predictable results to one of ordinary skill in the art. KSR International Co. v. Teleflex Inc., 550 U.S. 398, __, 82 USPQ2d 1385, 1395 (2007). See also, MPEP 2143(A).
Regarding claim 2, Schulte teaches that the lattice-matched semiconducting material comprises one or more III-V semiconductors (see at least ¶[0051]-[0052] which teach the deposition of GaAs).
Regarding claim 3, Schulte teaches that the lattice-matched semiconducting material comprises GaAs or GaInP (see at least ¶[0051]-[0052] which teach the deposition of GaAs).
Regarding claim 4, Schulte teaches that the step of depositing the one or more lattice-matched semiconducting materials is performed at a temperature less than or equal to 750 °C (see at least ¶[0051]-[0052] which teach that a growth temperature of 650 °C).
Regarding claim 5, Schulte teaches that the step of depositing the one or more lattice-matched semiconducting materials further comprises:
flowing a group III source into a deposition chamber at a group III partial pressure (see Figs. 1-3 and ¶¶[0033]-[0044] as well as ¶[0051]-[0052] which teach flowing GaCl into a deposition chamber (100) at a Group III partial pressure); and
flowing a group V source into a deposition chamber at a group V partial pressure (see Figs. 1-3 and ¶¶[0033]-[0044] as well as ¶[0051]-[0052] which teach flowing AsH3 into the deposition chamber (100) at a Group V partial pressure).
Regarding claim 6, Schulte teaches that the group III source comprises GaCl or InCl (see at least ¶[0051]-[0052] which teaches that the Group III source material comprises GaCl).
Regarding claim 7, Schulte teaches that the group III source is generated in-situ by reacting anhydrous HCl with Ga or In (see Figs. 1-3 and ¶¶[0033]-[0044] as well as ¶[0051]-[0052] which teach flowing HCl (108) over a solid Ga source (106)).
Regarding claim 8, Schulte teaches that the group V source comprises AsH3 or PH3 (see at least ¶[0051]-[0052] which teaches that the Group V source material comprises AsH3).
Regarding claim 9, Schulte teaches that the group V partial pressure is less than or equal to 4 times the group III partial pressure (see Fig. 6(b) and ¶¶[0057]-[0060] which teach that the GaAs growth rate may be controlled to the desired value by controlling the relative GaCl and AsH3 flow rates and partial pressures with Fig. 6(b) specifically showing an embodiment in which PHCl(Ga) is approximately 3.4×10-3 atm while PAsH3 is 1.1×10-2 atm for a V/III ratio of 0.011/0.0034 = 3.2 which falls within the claimed range).
Regarding claim 12, Schulte teaches that the GaAs substrate is reusable (see Fig. 5 and ¶¶[0051]-[0054] which teach that the GaAs substrate is formed into a GaAs solar cell; moreover, the thus-deposited layers may be removed by, for example, an etching or grinding and CMP polishing process followed by one or more epitaxial growth processes which necessarily means that the GaAs substrate is capable of being reused for a different purpose).
Regarding claim 13, Schulte teaches generating an optoelectronic device (see Fig. 5 and ¶¶[0053]-[0054] which teach that the GaAs substrate is formed into a GaAs solar cell).
Claim 11 is/are rejected under 35 U.S.C. 103 as being unpatentable over Schulte in view of Allen and further in view of U.S. Patent Appl. Publ. No. 2010/0307572 to Bedell, et al. (“Bedell”).
Regarding claim 11, Schulte teaches that removing the GaAs substrate from the lattice matched semiconducting material via controlled spalling. However, in Figs. 1-4 and ¶¶[0016]-[0022] Bedell teaches an analogous method of producing a III-V photovoltaic cell (400) in which an optional back surface field layer (202) is initially formed on a Group III-V substrate such as GaAs. This is followed by the deposition of a tensile stressed metal layer (203) and a flexible substrate layer (204) is adhered to the metal layer (203). The flexible substrate (204) is used to produce tensile stress in the metal layer (203) in order to produce a fracture (302) in the substrate (201) such that a thin base layer (301) is spalled from the substrate and may be used to form a III-V PV cell (400). Thus, a person of ordinary skill in the art prior to the effective filing date of the invention would be motivated to utilize the controlled spalling technique of Bedell to remove a thin layer of the homoepitaxial GaAs(110) layer produced in the method of Schulte and Allen by spalling in order to produce multiple thin GaAs(110) substrates that may be used for the production of electronic and optoelectronic devices thereupon.
Response to Arguments
Applicants’ arguments filed May 28, 2026, have been fully considered but they are not persuasive.
Applicants initially argue that given the substantial differences between MBE and HVPE an ordinary artisan would not be motivated to combine the teachings of Allen and Schulte. See applicants’ 5/28/2026 reply, pp. 8-9. Applicants’ argument is noted, but is unpersuasive. While there certainly are some differences between MBE and HVPE, they ultimately both involve thin film growth in which a gaseous precursor is adsorbed onto a substrate. In both growth techniques the nature of the substrate, whether it is a single crystal, polycrystalline, or amorphous has a significant influence on the growth mode and resulting microstructure of the deposited thin film. Moreover, if the substrate is crystalline then the crystal structure and its orientation at the growth surface play a significant role in determining the growth mode that occurs at the onset of growth. This is evident from the fact that both Schulte and Allen utilize single crystal GaAs substrates with a surface crystal plane that is offset by a predetermined amount in specific crystallographic directions. In Schulte a GaAs(001) surface plane is used with a miscut of 4°, 6°, or 9° in the (111) direction. In ¶[0064] Schulte specifically teaches that a higher miscut produces a higher step density which provides additional Group V terminated surface steps/kinks which, in turn, influences the incorporation of dopant atoms during film growth. Then in at least Figs. 6-8 and the Discussion section at pp. 198-99 Alen teaches that faceting during growth on the GaAs(110) surface may be suppressed by angling the substrate towards the (111)Ga surface such that chemisorption (and not just physical deposition) of incoming As species and layer-by-layer growth is promoted during MBE deposition. Thus, the crystal structure and orientation of the substrate influences the growth mode regardless of whether it is performed by MBE or HVPE. The one advantage of HVPE over MBE is that it facilitates growth at significantly higher growth rates. In this regard, a PHOSITA would be motivated to utilize the GaAs(110) substrates of Allen which are miscut in the (111) direction as a template for film growth by HVPE to produce epitaxial layers with improved properties such as being facet-free with more predictable doping levels at a higher growth rate.
Applicants then argue that Allen does not teach a miscut angle of up to 6°, but rather specifically teach a miscut of exactly 6°. Id. at p. 9. Applicants’ argument is noted, but is unpersuasive. In at least Figs. 6-8 and the Discussion section at pp. 198-99 Alen specifically teaches that faceting during growth on the GaAs(110) surface may be suppressed by angling the substrate towards (111)Ga. This has the effect of producing a miscut in which the step density is directly proportional to the miscut angle. The presence of step edges as a result of the miscut then promotes two-dimensional or layer-by-layer growth. The specific reference to “angling the substrate” indicates that a range of miscuts are considered and that the desired effect is not limited to a specific miscut angle. The miscut angle of 6° referenced in Fig. 7 and the paragraph on p. 198 is provided as but one example to show that a miscut substrate does, indeed, produce the desired effect. The Examiner’s position is supported by Chinese Patent Appl. Publ. No. CN 102379033A to Hirotaka Geka (“Geka”) which was cited as pertinent prior art of record. In at least ¶¶[0033]-[0035] Geka teaches the use of a vapor-phase deposition technique such as MBE, MOCVD, and the like for epitaxial growth on a GaAs(110) substrate with an offset angle of 1 to 5° which therefore encompasses an offset angle of 3° as claimed. It is also pointed out that applicants have not provided evidence showing that a miscut of 3° is critical and produces unexpected results.
Conclusion
THIS ACTION IS MADE FINAL. 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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/KENNETH A BRATLAND JR/Primary Examiner, Art Unit 1714
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