The present application, filed on or after March 16, 2013, is being examined under the first inventor to file provisions of the AIA .
DETAILED ACTION
Priority
Claim 16 is not entitled to the benefit of the prior application US 15/318,541, and is given an effective filing date of 3/16/21, as stated in the previous office action.
Election/Restrictions
Newly submitted claims 19-21 are directed to an invention that is independent or distinct from the invention originally claimed for the following reasons:
Claim 19 discloses a limitation: “the radicals are produced by expansion of the process gas”, however the elected embodiment of Fig 5 clearly discloses that “radicals NH2* are produced thermally or by other type of energy feed”. Radical production (GeH3*) by pneumatic expansion of the process gas is only disclosed in the embodiments of Fig 1, which was not elected.
Claims 20 and 21 are dependent on claim 19.
Since applicant has received an action on the merits for the originally presented invention, this invention has been constructively elected by original presentation for prosecution on the merits. Accordingly, claims 19-21 are withdrawn from consideration as being directed to a non-elected invention. See 37 CFR 1.142(b) and MPEP § 821.03.
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)(1) the claimed invention was patented, described in a printed publication, or in public use, on sale or otherwise available to the public before the effective filing date of the claimed invention.
Claims 1-3 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by S. Wirths et al. "Reduced pressure CVD growth of Ge and GeSn alloys" found in IDS, hereinafter Ref 1.
Fig 1 of Ref 1 discloses a method for depositing a monocrystalline semiconductor layer [GeSn] consisting of a first element and a second element,
1. “wherein the first element [Ge] is fed as part of a hydride [Ge2H6], and the second element [Sn] is fed as part of a halide [SnCl4], together with a carrier gas formed by an inert gas [N2], into a process chamber of a CVD reactor [Tricent CVD-tool], wherein:
the first element is N, As, P, or Sb and the second element is Ga, In, or Al, or
the first element is C, Si, or Ge [Ge], and the second element is C, Si, Ge, or Sn [Sn];
wherein gaseous radicals [GeH3] are produced [due to low pressure] from the hydride [Ge2H6] at a distance away from a surface of a semiconductor substrate [Si wafer], wherein the radicals have the property to decompose at a temperature higher but not lower than a decomposition temperature [inherent property of the radicals to decompose at a high enough temperature];
wherein at a temperature of the substrate [375ºC] below said decomposition temperature, at a total pressure of the gas in the process chamber low enough to avoid a reverse reaction of the radicals in the gas phase [reduced pressure CVD 60 mbar], the radicals [GeH3] and the halide [SnCl4] are brought to the surface of the semiconductor substrate [Si] which is heated to a substrate temperature [375ºC] lower than said decomposition temperature;
wherein the method comprising a first chemical surface reaction [exothermic reaction] in which the radicals [GeH3] react exothermically with the halide [SnCl4] at the surface of the semiconductor substrate [Si], wherein products of the first reaction comprising atoms of the first element [Ge] and atoms of the second element [Sn] and heat released during the first reaction remaining at the surface of the semiconductor substrate; wherein the method comprising a second chemical surface reaction [endothermic reaction] in which the radicals [GeH3] decompose endothermically into atoms of the first element [Ge] remaining at the surface of the semiconductor substrate [Si]; wherein said heat being released during the first reaction [exothermic reaction] drives the second chemical surface reaction [endothermic reaction] and locally heats the surface of the substrate to a temperature high enough for the atoms of the first element [Ge] and of the second element [Sn] to be integrated into the surface in crystalline order [high crystalline quality].” The results and discussion section of Ref 1 describes the highly crystalline GeSn layer being grown by kinetically controlled, radical-assisted epitaxial growth, in particular see page 101, 2nd column.
2. “wherein the formation of the radicals takes place with no presence of H2.” The carrier gas is N2.
3. “wherein the temperature lower than the decomposition temperature of the radical is defined as the temperature at which only an extremely small growth of less than 1 nm/h of the first element on the substrate would take place without the admixture of said halide.” See Fig 2 and page 101 2nd column “radical-assisted growth”.
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 15 is rejected under 35 U.S.C. 103 as being unpatentable over Ref 1 as applied to claim 1 above.
Ref 1 discloses using Ge2H6 and SnCl4 as precursors to epitaxially grow GeSn, but does not disclose growing layers of different materials.
15. “wherein the hydride is NH3 or NH2R, wherein R is an organic group and where the halide comprises Ga.”
However, using GaCl3 and NH3 as precursors together with N2 gas to epitaxially grow GaN is well known in the art, as evidenced by APA2.
It would have been obvious to one of ordinary skill in the art at the time the of the invention to grow the semiconductor layers of these known materials/elements, since it has been held to be within the general skill of a worker in the art to select a known material/element on the basis of its suitability for the intended use as a matter of obvious design choice. In re Leshin, 227 F.2d 197, 125 USPQ 416 (CCPA 1960).
Admitted Prior Art
The rejection based on the well-known in the art statement (CVD reactors are well known in the art for growing semiconductor layers) is taken to be admitted prior art (hereinafter APA1) because applicant either failed to traverse the examiner’s assertion of official notice or that the traverse was inadequate, see MPEP 2144.03.
The rejection of claim 15 based on the well-known in the art statement (GaCl3 and NH3 as precursors are known to epitaxially grow GaN) is taken to be admitted prior art (hereinafter APA2) because applicant either failed to traverse the examiner’s assertion of official notice or that the traverse was inadequate, see MPEP 2144.03.
Claim Interpretation
The claims in this application are given their broadest reasonable interpretation using the plain meaning of the claim language in light of the specification as it would be understood by one of ordinary skill in the art. The broadest reasonable interpretation of the claim elements (also commonly referred to as the claim limitations) are limited by applicant’s comments filed on 12/06/24. Regarding claim 1, the limitations “a reverse reaction”, “pressure of gas low enough”, “temperature high enough”, “temperature lower than said decomposition temperature” are interpreted as described in the applicant’s comments on pages 9 and 10 of the reply.
Response to Arguments
Applicant’s arguments with respect to claim 1, filed on 9/24/25 have been considered but they are not persuasive.
Regarding applicant’s arguments that “Ref 1 fails to specify that the dissociation of Ge2H6 may take place at a distance away from the surface of the semiconductor substrate”, the examiner disagrees and points out that the reference clearly discloses that “part of Ge2H6 already dissociates in the gas phase and reactive GeH3 may accelerate the growth process” (p. N100 1st col.). Furthermore, the term “at a distance away” is not a precise measurement, Fig 1 clearly shows that the precursor gas is coming from the shower head that is located above the substrate, identical to Fig 1 of applicant’s invention.
Regarding applicant’s arguments that “Ref 1 fails to disclose the temperature-pressure-regime in the process chamber”, the examiner disagrees and points out that Ref 1 clearly discloses that the process take place at 375ºC, at a reactor pressure of 60 mbar, which are the same temp and pressure as used by the applicant. The reference further discloses that the temperature and pressure are precisely controlled.
Regarding applicant’s arguments that “Ref 1 assumes that kinetic limited growth is limited by surface reactions”, the examiner disagrees and points out that Ref 1 clearly discloses “a growth rate increase in the kinetically controlled growth regime was ascribed to radical-assisted growth”.
Regarding applicant’s arguments that “the extent temperature is even discussed it is in the context of an overall temperature inside the reactor chamber”, the examiner disagrees and points out that Ref 1 clearly discloses in Fig 1 that the susceptor is heated by IR lamps, the growth substrate wafer is placed directly on the susceptor and is heated by it to the desired temperature.
Regarding applicant’s arguments that “only with the specific conditions claimed by Applicant is it possible that the first and second reactions take place”, the examiner points out that Ref 1 discloses the same apparatus as the applicant, the same growth conditions as the applicant, and the same outcome of growing high crystallinity thin films as the applicant. Therefore, the reference discloses the same growth method as the applicant.
Regarding applicant’s arguments that “Ref 1 does not disclose the words exothermic reaction and endothermic reaction”, the examiner points out that the lack of verbatim recitation does not mean that these reactions do not take place, these terms merely classify common types of chemical reactions and are not named outside of chemistry textbooks. If these types of reactions were not taking place, then the process disclosed by Ref 1 would not achieve the same results as the applicant. Furthermore, the reference clearly discloses “for our growth conditions, Ge2H6 dissociates into GeH3 radicals which may accelerate the surface reactions.”
Regarding applicant’s argument that “both first and second chemical reactions must take place at the surface of the substrate” and “there is nothing in Ref 1 that suggests these recited elements of claim 1” the examiner points out that if these reactions were not taking place at the surface of the growth substrate, then the high crystalline GeSn layer would not epitaxially grow on the surface of the substrate. The reference does not disclose GeSn layer to be floating in space, but epitaxially gown on the surface of a Si(100) substrate.
Pertinent Art
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. Applicant’s attention is drawn to the references cited on form PTO-892 in the previous office action, which lists other references with similar features as the invention.
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.
Contact Info
Any inquiry concerning this communication or earlier communications from the examiner should be directed to M. A. GOLUB-MILLER whose telephone number is (571)272-8602. The examiner can normally be reached on M-F 9-5.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, MinSun Harvey can be reached on (571) 272-1835. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/M. A. Golub-Miller/ Primary Examiner, Art Unit 2828