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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 April 2, 2026, has been entered.
Claim Interpretation
The following is a quotation of 35 U.S.C. 112(f):
(f) Element in Claim for a Combination. – An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
The following is a quotation of pre-AIA 35 U.S.C. 112, sixth paragraph:
An element in a claim for a combination may be expressed as a means or step for performing a specified function without the recital of structure, material, or acts in support thereof, and such claim shall be construed to cover the corresponding structure, material, or acts described in the specification and equivalents thereof.
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 a claim element (also commonly referred to as a claim limitation) is limited by the description in the specification when 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is invoked.
As explained in MPEP § 2181, subsection I, claim limitations that meet the following three-prong test will be interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph:
(A) the claim limitation uses the term “means” or “step” or a term used as a substitute for “means” that is a generic placeholder (also called a nonce term or a non-structural term having no specific structural meaning) for performing the claimed function;
(B) the term “means” or “step” or the generic placeholder is modified by functional language, typically, but not always linked by the transition word “for” (e.g., “means for”) or another linking word or phrase, such as “configured to” or “so that”; and
(C) the term “means” or “step” or the generic placeholder is not modified by sufficient structure, material, or acts for performing the claimed function.
Use of the word “means” (or “step”) in a claim with functional language creates a rebuttable presumption that the claim limitation is to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites sufficient structure, material, or acts to entirely perform the recited function.
Absence of the word “means” (or “step”) in a claim creates a rebuttable presumption that the claim limitation is not to be treated in accordance with 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. The presumption that the claim limitation is not interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, is rebutted when the claim limitation recites function without reciting sufficient structure, material or acts to entirely perform the recited function.
Claim limitations in this application that use the word “means” (or “step”) are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office action. Conversely, claim limitations in this application that do not use the word “means” (or “step”) are not being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, except as otherwise indicated in an Office action.
This application includes one or more claim limitations that use the word “means” and are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph. Such claim limitation(s) is/are: the “heating means” in claims 16 and 29.
Because this/these claim limitation(s) is/are being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, it/they is/are being interpreted to cover the corresponding structure described in the specification as performing the claimed function, and equivalents thereof.
If applicant does not intend to have the claim limitation(s) treated under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112 , sixth paragraph, applicant may amend the claim(s) so that it/they will clearly not invoke 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, or present a sufficient showing that the claim recites/recite sufficient structure, material, or acts for performing the claimed function to preclude application of 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph.
The claim limitations relating to the “heating means” in claims 16 and 29 has/have been interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, because it uses/they use a generic placeholder “means” coupled with functional language “heating” without reciting sufficient structure to achieve the function. Furthermore, the generic placeholder is not preceded by a structural modifier.
Since the claim limitation(s) invokes 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, claims 16 and 29 has/have been interpreted to cover the corresponding structure described in the specification that achieves the claimed function, and equivalents thereof.
A review of the specification shows that the following appears to be the corresponding structure described in the specification for the 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph limitation:
the induction coil (70) in Fig. 3, ¶[0046], and ¶[0053] of the published application is equated with the heating means as claimed.
If applicant wishes to provide further explanation or dispute the examiner' s interpretation of the corresponding structure, applicant must identify the corresponding structure with reference to the specification by page and line number, and to the drawing, if any, by reference characters in response to this Office action.
If applicant does not intend to have this/these limitation(s) interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph, applicant may: (1) amend the claim limitation(s) to avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph (e.g., by reciting sufficient structure to perform the claimed function); or (2) present a sufficient showing that the claim limitation(s) recite(s) sufficient structure to perform the claimed function so as to avoid it/them being interpreted under 35 U.S.C. 112(f) or pre-AIA 35 U.S.C. 112, sixth paragraph.
For more information, see MPEP § 2173 et seq. and Supplementary Examination Guidelines for Determining Compliance With 35 U.S.C. 112 and for Treatment of Related Issues in Patent Applications, 76 FR 7162, 7167 (Feb. 9, 2011).
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.
Claim(s) 16, 18-25 and 27-30 is/are rejected under 35 U.S.C. 103 as being unpatentable over U.S. Patent Appl. Publ. No. 2009/0126624 to Syvajarvi, et al. (“Syvajarvi”) in view of U.S. Patent Appl. Publ. No. 2014/0220298 to Mark Loboda (“Loboda”) and further in view of U.S. Patent Appl. Publ. No. 2020/0144047 to Anzalone, et al. (“Anzalone”) and still further in view of U.S. Patent Appl. Publ. No. 2012/0091482 to Uchida, et al. (“Uchida”).
Regarding claim 16, Syvajarvi teaches a system for producing an epitaxial monocrystalline layer on a substrate (see the Abstract, Figs. 1-6, and entire reference which teach a system and method for depositing an epitaxial layer on a substrate (20)) comprising:
an inner container defining a cavity for accommodating a source material and the substrate (see Figs. 1-4 and ¶¶[0024]-[0036] which teach an inner container (31) and (32) which defines a cavity for accommodating a source material (10) and substrate (20));
an insulation container arranged to accommodate the inner container therein (see Fig. 1 and ¶¶[0024]-[0028] which teach an insulation container (50) which accommodates the inner container (31) and (32));
an outer container arranged to accommodate the insulation container and the inner container therein (see Fig. 1 ¶¶[0024]-[0028] which teach an outer container (60) which accommodates the insulation (50) and inner containers (31) and (32)); and
heating means arranged outside the outer container and configured to heat the cavity (see Fig. 1 and ¶¶[0024]-[0028] which teach a heating means (70) in the form of an induction coil arranged outside the outer container (60) to heat the cavity),
wherein the inner container comprises a spacer element arranged to support the substrate at a predetermined distance above a solid monolithic source material, said predetermined distance being defined by a height (H) of the spacer elements (see Fig. 4 and ¶[0036] which teaches that a spacer (3) is arranged to support the substrate (20) a predetermined distance from the solid monolithic source material (10) which is defined by the height of the spacer (3)),
wherein each spacer element comprises a base portion and a top portion arranged to contact the substrate (see Fig. 4 and ¶[0036] which teach that the spacer (30) includes a base portion and a top portion which contacts the substrate (20)).
Syvajarvi does not teach that there are a plurality of spacer elements. However, in Fig. 3 and ¶¶[0053]-[0054] as well as elsewhere throughout the entire reference Loboda teaches an analogous embodiment of a sublimation growth system which includes, inter alia, a crucible (40) which positions a seed crystal (48) opposite a source material (42) in order to deposit an epitaxial layer by sublimation-recondensation of the source material (42). In Fig. 3 the seed crystal (48) is supported by a flow ring (50) which includes a plurality of bumps or extensions (58) which produce a setback from the seed (48) such that gas is directed to flow between the gas flow ring (50) and the seed (48). Thus, a PHOSITA prior to the effective filing date of the invention would look to the teachings of Loboda and would be motivated to provide the spacer (3) of Syvajarvi with a plurality of spacer elements in the form of bumps or extensions (58) arranged around the circumference of the spacer (3) in order to promote a more uniform flow of gas over the substrate surface during epitaxial growth.
Syvajarvi and Loboda do not teach that each spacer element tapers towards an apex arranged to contact the substrate. However, in Figs. 1-9 and ¶¶[0021]-[0053] as well as elsewhere throughout the entire reference Anzalone teaches an analogous embodiment of a support (20) for a substrate (58) provided in a reaction chamber (10). The support (20) includes a plurality of arms (30) which possess a body portion (44) and a raised portion (46) which is used to support the substrate (58). As explained specifically in Figs. 6-8 and ¶¶[0046]-[0050] the raised portion (46) includes an upper surface (54) which provides a planar portion for the substrate (58) to rest upon. In order to minimize the contact area between the upper surface (54) and the substrate (58), the upper surface (54) is made as small as possible and this is achieved by providing the top of the raised portion (46) in the shape of a pyramid having a plurality of side surfaces (56) which are slanted inwards and terminate with the upper surface (54). Thus, a PHOSITA prior to the effective filing date of the invention would look to the teachings of Anzalone and would be motivated to provide the bumps or extensions (58) of Loboda as raised portions (46) which taper towards an upper surface (54) that is as small as possible in order to minimize the contact area between the spacer/extension(s) and the substrate such that the spacer/extension(s) are less likely to stick to the substrate after epitaxial growth.
Syvajarvi, Loboda, and Anzalone do not teach that the entirety of the top portion of the spacer element tapers from the base portion to the apex. However, in Figs. 2A-D and ¶¶[0086]-[0097] as well as elsewhere throughout the entire reference Uchida teaches an analogous method of depositing a material onto a substrate by sublimation/evaporation of a source material. This is achieved by initially providing a source material in the form of a transfer layer (11) on a transfer substrate (12) which is then placed such that it faces and is separated from an element substrate (1) by means of a plurality of spacers (13). As shown specifically in Figs. 2B-C there are a plurality of said spacers (13) and they have a smooth and continuous taper which extends from the base on the element substrate (1) to an apex which contacts the transfer substrate (12). The transfer substrate is heated by a heat source (15) under vacuum conditions in Fig. 2C in order to cause the transfer layer (11) to evaporate/sublime and deposit upon the element substrate (1). Thus, a PHOSITA prior to the effective filing date of the invention would look to the teachings of Uchida and would be motivated to provide the entirety of the plurality of spacer elements as taught by Loboda, and Anzalone with a tapered shape which extends entirely from a base portion to an apex which contacts the substrate in order to provide a smooth and continuous laminar flow path for the precursor vapor as it transitions from the source material to the substrate such that more uniform film growth occurs. 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 18, Syvajarvi and Loboda do not teach that the spacer elements have a shape chosen from a pyramid, a cone, a tetrahedron and a prism. However, as noted supra with respect to the rejection of claim 16, in Figs. 6-8 and ¶¶[0042]-[0053] Anzalone teaches that the raised portion (46) may be pyramid shaped with four side surfaces (56); accordingly, a PHOSITA prior to the effective filing date of the invention would recognize that the entire tapered portion of the spacer (13) in Uchida may be in the form of a pyramid or prism as this would involve nothing more than the use of a known shape according to its intended use).
Regarding claim 19, Syvajarvi and Loboda do not teach that each spacer element has a height (H), and the base portion has a transverse width (D), wherein the ratio between the height (H) and the transverse width (D) is from 1:3 to 3:1. However, in ¶[0018] Anzalone teaches that the size and relative positions of features in the drawings are not necessarily drawn to scale which indicates that in some embodiments they may be approximated as being drawn to scale. In this regard a physical measurement of a printout of Fig. 8 shows that the width of the raised portion (46) is 2.5 cm while the vertical height of the side surfaces (56) is 1.0 cm. This therefore means that the ratio of the height to the width is 1:2.5 which falls within the claimed range. Alternatively, since the width of the raised portion (46) and the slope of the side surfaces (56) determine the footprint and transition degree leading up to the actual contact area formed by the upper surface (54) it therefore would have been within the capabilities of a person of ordinary skill in the art prior to the effective filing date of the invention to utilize routine experimentation to determine the optimal ratio between the height of the side surfaces (56) and width of the raised portion (46) in Fig. 8 of Anzalone and, consequently, the width and height of the spacers (13) Fig. 2 of Uchida that is necessary to optimize epitaxial growth in the vicinity of the bumps or extensions (58) of Loboda such that a more uniform epitaxial SiC layer may be deposited while still facilitating ease of removal of the substrate once growth has completed.
Regarding claim 20, Syvajarvi and Loboda do not teach that the height (H) of each spacer element is about 0.7-1.4 mm and the transverse width (D) is smaller than or equal to 2.5 mm. However, in Figs. 6-8 and ¶¶[0042]-[0053] Anzalone teaches that there is a distance D4 between an upper surface (48) of a body portion (44) and the upper surface (54) of the raised portion (46) which has a value of D4 = 0.5 to 3 mm which would encompass the claimed height (H) of 0.7 to 1.4 mm. Then in ¶[0018] Anzalone teaches that the size and relative positions of features in the drawings are not necessarily drawn to scale which indicates that in some embodiments they may be approximated as being drawn to scale. In this regard a physical measurement of the height D4 in Fig. 8 shows that the height of D4 on paper is physically 1.9 cm. Thus, as per the discussion supra with respect to the rejection of claim 19, if D4 is 1.9 mm this means that the vertical height of the side surface (56) is 1 cm × (1.9 mm/1.9 cm) = 1.0 mm while the width of the raised portion (46) is 2.5 cm × (1.9 mm/1.9 cm) = 2.5 mm, both of which fall within the claimed ranges. Alternatively, since the width of the raised portion (46) and the vertical height of the side surfaces (56) determine the footprint and transition degree leading up to the actual contact area formed by the upper surface (54) it therefore would have been within the capabilities of a person of ordinary skill in the art prior to the effective filing date of the invention to start with a value in the range of D4 = 0.5 to 3 mm and would utilize routine experimentation to determine the optimal vertical height of the side surfaces (56) and width of the raised portion (46) in Fig. 8 of Anzalone and, consequently, the width and height of the spacers (13) Fig. 2 of Uchida that is necessary to optimize epitaxial growth in the vicinity of the bumps or extensions (58) of Loboda such that a more uniform epitaxial SiC layer may be deposited while still facilitating ease of removal of the substrate once growth has completed.
Regarding claim 21, Syvajarvi and Loboda do not teach that a ratio between a surface area of the apex and a surface area of the base portion is from 1:1000 to 1:5. However, in ¶[0018] Anzalone teaches that the size and relative positions of features in the drawings are not necessarily drawn to scale which indicates that in some embodiments they may be approximated as being drawn to scale. In this regard a physical measurement of Fig. 7 shows that the width of the raised portion (46) is 2.5 cm while the width of the upper surface (54) is 0.2 cm. This translates to a cross-sectional surface area of 2.5 cm × 2.5 cm = 6.25 cm2 for the raised portion (46) and a surface area of 0.2 cm × 0.2 cm = 0.04 cm2 for the upper surface (54). The ratio of a surface area of the apex and a surface area of the base portion is therefore 0.04 : 6.25 or 1 : 156.25 which falls within the claimed range. Alternatively, since the width of the raised portion (46), the slope of the side surfaces (56), and the area of the upper surface (54) determine the footprint and transition degree leading up to the actual contact area formed by the upper surface (54) it therefore would have been within the capabilities of a person of ordinary skill in the art prior to the effective filing date of the invention to start with a value in the range of D4 = 0.5 to 3 mm for a length of a side of the raised portion and utilize routine experimentation to determine the optimal ratio between a surface area of the upper surface (54) and a cross-sectional surface area of the raised portion (46) in Figs. 7-8 of Anzalone and, consequently, the surface area and cross-sectional area of the spacers (13) Fig. 2 of Uchida that is necessary to optimize epitaxial growth in the vicinity of the bumps or extensions (58) of Loboda such that a more uniform epitaxial SiC layer may be deposited while still facilitating ease of removal of the substrate once growth has completed.
Regarding claim 22, Syvajarvi and Loboda do not teach that the surface area of the apex is about 100 mm2. However, as noted supra with respect to the rejection of claims 19-21, in Figs. 6-8 and ¶¶[0042]-[0053] Anzalone teaches that there is a distance D4 between an upper surface (48) of a body portion (44) and the upper surface (54) of the raised portion (46) which has a value of D4 = 0.5 to 3 mm. Then in ¶[0018] Anzalone teaches that the size and relative positions of features in the drawings are not necessarily drawn to scale which indicates that in some embodiments they may be approximated as being drawn to scale. In this regard a physical measurement of the height D4 in Fig. 8 shows that the height of D4 on paper is physically 1.9 cm. Thus, as detailed supra with respect to the rejection of claims 19-20, if D4 is 0.5 mm this means that a side of the square that forms the upper surface (54) has a width of 0.2 cm × (0.5 mm/1.9 cm) = 0.05 mm or 50 mm. This, in turn, means that the surface area of the upper surface (54) would be 2,500 mm2. Since the area of the upper surface (54) determines how much contact there is between the underlying support and the substrate itself, the area of the upper surface (54) is therefore considered to be a result-effective variable, i.e., a variable which achieves a recognized result. See, e.g., In re Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977). See also MPEP 2144.05(II)(B). It therefore would have been within the capabilities of a person of ordinary skill in the art prior to the effective filing date of the invention to start with an area in the vicinity of 2,500 mm2 and utilize routine experimentation to determine the optimal area of the upper surface (54) of the raised portion (46) in Figs. 6-8 of Anzalone and, consequently, the upper surface of the spacers (13) in Fig. 2 of Uchida and would be motivated to make the area as small as possible to minimize the actual contact between the underlying support and the substrate such that a more uniform epitaxial SiC layer may be deposited while still facilitating ease of removal of the substrate once growth has completed.
Regarding claim 23, Syvajarvi, Anzalone, and Uchida do not teach that the spacer elements are regularly distributed about the circumference of the substrate. However, in Fig. 3 of Loboda the bumps/extensions (58) are regularly distributed around the circumference of the substrate (48). Thus, a person of ordinary skill in the art prior to the effective filing date of the invention would be motivated to provide a regular distribution of bumps/extensions (58) around the circumference of the ring (50) and, hence, the substrate (48) in order to promote a more uniform flow of gases around a periphery of the substrate (48).
Regarding claim 24, Syvajarvi, Anzalone, and Uchida do not teach that the spacer elements are made of tantalum, niobium, tungsten, hafnium, silicon carbide, graphite and/or rhenium. However, in at least ¶[0052] Loboda teaches that the spacer (50) should be made of a material compatible with the process temperature and chemistry used in SiC growth such as graphite.
Regarding claim 25, Syvajarvi teaches that the inner container is cylindrical, and wherein the substrate and the source material are disk-shaped (see Figs. 1-4 and ¶¶[0024]-[0036] which teach that the inner container (32) is cylindrical and that the source (10) and substrate (20) are disk-shaped), but does not explicitly teach that the inner diameter is in the range of 100 to 500 mm. However, in ¶[0014] Syvajarvi teaches that the method can be used to produce epitaxial layers having a diameter of up to 300 mm while ¶[0045] of Loboda teaches the use of SiC seeds having a diameter of from 76 mm up to 150 mm. Thus, in order to accommodate a seed crystal (20) having a diameter of from 150 up to 300 mm a person of ordinary skill in the art prior to the effective filing date of the invention would be motivated to utilize an inner container (32) in Figs. 1-4 of Syvajarvi which has an inner diameter which is slightly greater than the 150 to 300 mm diameter of the SiC substrate such that the substrate itself may be accommodated within the inner container and utilized as the substrate (20) during epitaxial deposition.
Regarding claim 27, Syvajarvi teaches that the surface area of the source material (10) is greater than or equal to the surface area of the substrate (see Figs. 1-4 and ¶¶[0024]-[0036] which teach that the planar surface area of the source (10) is equal to the planar surface area of the substrate (20)).
Regarding claim 28, Syvajarvi teaches the use of a carbon getter arranged in the inner container (see at least ¶[0009], ¶[0014], and claims 8-9 which teach that the quality of the epitaxial layer may be increased by providing a carbon getter within the inner container (32)).
Regarding claim 29, Syvajarvi teaches a method of producing an epitaxial monocrystalline layer on a substrate (see the Abstract, Figs. 1-6, and entire reference which teach a method for depositing an epitaxial layer on a substrate (20)) comprising:
providing (S100) an inner container defining a cavity for accommodating a source material and the substrate (see Figs. 1-4 and ¶¶[0024]-[0036] which teach providing an inner container (31) and (32) which defines a cavity for accommodating a source material (10) and substrate (20));
arranging a solid monolithic source material in the cavity (see Figs. 1-4 and ¶¶[0024]-[0036] which teach providing a solid monolithic source material (10) in the inner container (32));
arranging (S104) the substrate at a predetermined distance above the source material by using a spacer element, said predetermined distance being defined by a height (H) of the spacer elements, wherein each spacer element comprises a base portion and a top portion, wherein at least part of the top portion is arranged to contact the substrate (see Fig. 4 and ¶[0036] which teaches that a spacer (3) is arranged to support the substrate (20) a predetermined distance from the solid monolithic source material (10) which is defined by the height of the spacer (3); moreover, the spacer (30) includes a base portion and a top portion which contacts the substrate (20));
arranging the inner container within an insulation container (see Fig. 1 and ¶¶[0024]-[0028] which teach providing an insulation container (50) which accommodates the inner container (31) and (32));
arranging the insulation container and the inner container within an outer container (see Fig. 1 ¶¶[0024]-[0028] which teach providing an outer container (60) which accommodates the insulation (50) and inner containers (31) and (32));
providing heating means outside the outer container to heat the cavity (see Fig. 1 and ¶¶[0024]-[0028] which teach providing a heating means (70) in the form of an induction coil arranged outside the outer container (60) to heat the cavity);
evacuating (S106) the cavity to a predetermined low pressure of lower than 10-4 mbar (see Fig. 1, ¶[0024], and ¶[0040] which teach that the cavity is evacuate to a low pressure of 10-4 to 10-6 mbar using conventional pumping means);
raising (S110) the temperature in the cavity to a predetermined growth temperature by the heating means; maintaining (S 112) the predetermined growth temperature in the cavity until a predetermined thickness of the epitaxial monocrystalline silicon carbide layer on the substrate has been achieved; and cooling (S114) the substrate (see Fig. 5 and ¶¶[0040]-[0047] which teach that the temperature is raised to a growth temperature (413) during heating phases (401) and (402) and then held at the growth temperature (413) during a growth phase (403) in order to grow a SiC epitaxial layer having a predetermined thickness (414) and this is then followed by turning off the heater and cooling to room temperature in step (404)).
Syvajarvi does not explicitly teach the step of introducing (S108) an inert gas into the cavity. However, in Fig. 3, ¶[0035], ¶¶[0057]-[0060],and claim 1 Loboda teaches that after the furnace (70) is evacuated using pump (92) it is backfilled with an inert gas such as argon (88) in order to flush out any impurities such as oxygen-containing gas molecules. Thus, a person of ordinary skill in the art prior to the effective filing date of the invention would be motivated to introduce an inert gas into the inner container (32) after it has been evacuated in the method of Syvajarvi in order to promote the removal of contaminants such as oxidizing gas molecules prior to performing SiC epitaxial growth in order to produce a higher quality epitaxial layer with a reduced impurity content.
Syvajarvi also does not teach that there are a plurality of spacer elements. However, in Fig. 3 and ¶¶[0053]-[0054] as well as elsewhere throughout the entire reference Loboda teaches an analogous embodiment of a sublimation growth system which includes, inter alia, a crucible (40) which positions a seed crystal (48) opposite a source material (42) in order to deposit an epitaxial layer by sublimation-recondensation of the source material (42). In Fig. 3 the seed crystal (48) is supported by a flow ring (50) which includes a plurality of bumps or extensions (58) which produce a setback from the seed (48) such that gas is directed to flow between the gas flow ring (50) and the seed (48). Thus, a PHOSITA prior to the effective filing date of the invention would look to the teachings of Loboda and would be motivated to provide the spacer (3) of Syvajarvi with a plurality of spacer elements in the form of bumps or extensions (58) arranged around the circumference of the spacer (3) in order to promote a more uniform flow of gas over the substrate surface during epitaxial growth.
Syvajarvi and Loboda do not teach that each spacer element tapers towards an apex arranged to contact the substrate. However, in Figs. 1-9 and ¶¶[0021]-[0053] as well as elsewhere throughout the entire reference Anzalone teaches an analogous embodiment of a support (20) for a substrate (58) provided in a reaction chamber (10). The support (20) includes a plurality of arms (30) which posses a body 0ortion (44) and a raised portion (46) which is used to support the substrate (58). As explained specifically in ¶¶[0046]-[0050] the raised portion (46) includes an upper surface (54) which provides a planar portion for the substrate (58) to rest upon. In order to minimize the contact area between the upper surface (54) and the substrate (58), the upper surface (54) is made as small as possible and this is achieved by providing the top of the raised portion (46) in the shape of a pyramid having a plurality of side surfaces (56) which are slanted inwards and terminate with the upper surface (54). Thus, a PHOSITA prior to the effective filing date of the invention would look to the teachings of Anzalone and would be motivated to provide the bumps or extensions (58) of Loboda as raised portions (46) which taper towards an upper surface (54) that is as small as possible in order to minimize the contact area between the spacer/extension(s) and the substrate such that the spacer/extension(s) are less likely to stick to the substrate after epitaxial growth.
Syvajarvi, Loboda, and Anzalone do not teach that the entirety of the top portion of the spacer element tapers from the base portion to the apex. However, in Figs. 2A-D and ¶¶[0086]-[0097] as well as elsewhere throughout the entire reference Uchida teaches an analogous method of depositing a material onto a substrate by sublimation/evaporation of a source material. This is achieved by initially providing a source material in the form of a transfer layer (11) on a transfer substrate (12) which is then placed such that it faces and is separated from an element substrate (1) by means of a plurality of spacers (13). As shown specifically in Figs. 2B-C there are a plurality of said spacers (13) and they have a smooth and continuous taper which extends from the base on the element substrate (1) to an apex which contacts the transfer substrate (12). The transfer substrate is heated by a heat source (15) under vacuum conditions in Fig. 2C in order to cause the transfer layer (11) to evaporate/sublime and deposit upon the element substrate (1). Thus, a PHOSITA prior to the effective filing date of the invention would look to the teachings of Uchida and would be motivated to provide the entirety of the plurality of spacer elements as taught by Loboda, and Anzalone with a tapered shape which extends entirely from a base portion to an apex which contacts the substrate in order to provide a smooth and continuous laminar flow path for the precursor vapor as it transitions from the source material to the substrate such that more uniform film growth occurs. 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 30, Syvajarvi does not teach that the spacer elements are regularly distributed about the circumference of the substrate. However, in Fig. 3 of Loboda the bumps/extensions (58) are regularly distributed around the circumference of the substrate (48). Thus, a person of ordinary skill in the art prior to the effective filing date of the invention would be motivated to provide a regular distribution of bumps/extensions (58) around the circumference of the ring (50) and, hence, the substrate (48) in order to promote a more uniform flow of gases around a periphery of the substrate (48).
Claim(s) 26 is/are rejected under 35 U.S.C. 103 as being unpatentable over Syvajarvi in view of Loboda and further in view of Anzalone and still further in view of Uchida and even further in view of U.S. Patent Appl. Publ. No. 2017/0321345 to Xu, et al. (“Xu”).
Regarding claim 26, Syvajarvi, Loboda, Anzalone, and Uchida do not teach a heating body made of high-density graphite arranged below the inner container. However, in Figs. 2-4 and ¶¶[0034]-[0050] as well as elsewhere throughout the entire reference Xu teaches an analogous system and method for the growth of epitaxial SiC by the sublimation method. In Fig. 2 and ¶¶[0035]-[0036] Xu specifically teaches that the source material (2) contained within crucible (1) may be heated by a heater (40) made of dense graphite which is arranged below the crucible (1) itself. Thus, a person of ordinary skill in the art prior to the effective filing date of the invention would look to the teachings of Xu and would be motivated to incorporate a heating body made of high density graphite below the inner crucible (32) in the apparatus of Syvajarvi in order to provide greater control over the axial and radial temperature gradients produced during SiC epitaxial growth.
Response to Arguments
Applicants’ arguments filed April 2, 2026, have been fully considered, but they are not persuasive and are moot in view of the new grounds of rejection set forth in this Office Action
Applicants’ arguments against the combination of Syvajarvi, Loboda, and Anzalone at pp. 5-9 of applicants’ April 2, 2026, reply have been considered, but are not persuasive for reasons noted in the April 8, 2026, Advisory Action. Moreover, applicants’ amendments to claims 16 and 29 necessitated the introduction of U.S. Patent Appl. Publ. No. 2012/0091482 to Uchida, et al. to teach the newly added claim limitations.
Conclusion
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/KENNETH A BRATLAND JR/Primary Examiner, Art Unit 1714
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