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 .
Election/Restrictions
Applicant's election with traverse of Group IA in the reply filed on August 28, 2026 is acknowledged. However, the traversal is moot as Applicant has canceled all the claims relating to the other Groups, and instead added new claims directed to Group IA.
The requirement is still deemed proper and is therefore made FINAL.
Information Disclosure Statement
As of September 22, 2026, no information disclosure statement has been made of record.
Examiner reminds Applicant of their duty to disclosure. For example it appears that US 2017/0345891 A1 has the same Applicant as the current application. See https://en.wikipedia.org/wiki/Wolfspeed, where Cree, Inc. changed their name to Wolfspeed in 2021.
Drawing Objections
The drawings are objected to because:
Figure 1 needs to be labeled as prior art as Applicant in ¶ 0009 call figures 1 conventional. Conventional is what is routinely done in the art, e.g. prior art.
Figure 2 needs to be labeled as prior art. This is because as stated in ¶ 0053, figure 2 shows the crystallographic axis already present, and known to exist, in 4H SiC.
Figures 3A-3C need to be labeled as prior art. This is because as stated in ¶¶ 0054-57, what is being shown is what is already known about 4H SiC and its lattice structure. This is further evidenced by Applicant’s statement in ¶ 0057, where Applicant states the wafers are typically cut along the <11-20> axis.
Based upon US 2017/0345891 A1, Applicant will need to carefully go through their disclosure and mark all figures which were already known in the art before the filing date of the current application as “Prior Art”. Examiner has already illustrated some of the figures above.
The structure of claim 6 is not now shown in the drawings. This is because the drawings do not contain the limitations of claims 1 and 6.
The structure of 37 is objected for the same reason as claim 6 above.
Corrected drawing sheets in compliance with 37 CFR 1.121(d) are required in reply to the Office action to avoid abandonment of the application. Any amended replacement drawing sheet should include all of the figures appearing on the immediate prior version of the sheet, even if only one figure is being amended. The figure or figure number of an amended drawing should not be labeled as “amended.” If a drawing figure is to be canceled, the appropriate figure must be removed from the replacement sheet, and where necessary, the remaining figures must be renumbered and appropriate changes made to the brief description of the several views of the drawings for consistency. Additional replacement sheets may be necessary to show the renumbering of the remaining figures. Each drawing sheet submitted after the filing date of an application must be labeled in the top margin as either “Replacement Sheet” or “New Sheet” pursuant to 37 CFR 1.121(d). If the changes are not accepted by the examiner, the applicant will be notified and informed of any required corrective action in the next Office action. The objection to the drawings will not be held in abeyance.
Specification Objections
The disclosure is objected to because of the following informalities:
Applicant needs to move ¶¶ 0053-57 to the background section of the specification. This is because these paragraphs only detail what was known in the art about the structure of 4H SiC. Further, the structure of 4H SiC is not inventive. Rather, it appears Applicant is using the known structure of 4H SiC in their invention. Since, the structure of 4H SiC already known in the art is should be part of the background section.
Appropriate correction is required.
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) 1- is/are rejected under 35 U.S.C. 103 as obvious over Van Brunt et al. (US 2017/0345891 A1) (“Van Brunt”).
Regarding claim 1, Van Brunt teaches at least in figures 6A-7C:
a semiconductor epitaxial structure (220) having an off-axis orientation such that a crystallographic direction of the semiconductor epitaxial structure is non-perpendicular to a planar surface of the semiconductor epitaxial structure (¶¶ 0076-77, 82-83); and
a doped region (360) in the semiconductor epitaxial structure (220),
wherein the doped region (360) is formed by ion implantation (this is a product-by-process limitation as such how 360 is doped does not render the claim patentably distinct. However, Van Brunt is directed to ion implanting dopants into the SiC material) into the semiconductor epitaxial (220) structure along the crystallographic direction (it would have been obvious that the dopants of the guard rings would be formed in the same manner as the dopant of the n-pillars and p-pillars; ¶¶ 0012-15, where one can dope the SiC epitaxial layer at an angle along the crystallographic direction);
wherein the doped region (360) comprises a first region (a first side of 360; hereinafter “A”) and a second region (a second side of 360; hereinafter “B”),
wherein the first region (A) is perpendicular to the second region (B); and
wherein the first region and the second region have equal widths (as far as Examiner understands the first region and second region, these regions are the sides of the guard ring. Here 360 is a guard ring and as shown in the figures they have two perpendicular sides which appear to, and/or are obvious to, have the same width).
Regarding claims 2, and 33, Van Brunt teaches at least in figures 6A-7C:
wherein the crystallographic direction is offset at an angle of less than 10 degrees relative to a normal direction that is normal to the planar surface of the semiconductor epitaxial structure (¶ 0014).
Regarding claim 3, and 34, Van Brunt teaches at least in figures 6A-7C:
wherein the crystallographic direction of the semiconductor epitaxial structure is a crystallographic direction along which implant channeling occurs (¶¶ 0060-64).
Regarding claim 4, and 35, Van Brunt teaches at least in figures 6A-7C:
wherein the semiconductor epitaxial structure comprises a hexagonal crystal structure (figures 3A-3C), and
wherein the crystallographic direction of the semiconductor epitaxial structure comprises a <0001> direction of the hexagonal crystal structure (figure 2).
Regarding claim 5, and 36, Van Brunt teaches at least in figures 6A-7C:
wherein the doped region (360) comprises a guard ring (360 is a guard ring).
Regarding claim 6, and 37, Van Brunt teaches at least in figures 6A-7C:
wherein the semiconductor epitaxial structure (220) comprises a first conductivity type and having an epitaxial structure thereon that is configured as a drift region of the semiconductor device, wherein the semiconductor epitaxial structure has an active region formed on and/or in the drift region that is configured to block voltage in a reverse bias direction and providing current flow in a forward bias direction, wherein the guard ring is adjacent at least a portion of the active region of the semiconductor epitaxial structure (as best as Examiner understands it this limitation Applicant is claiming features from the background section in their ¶ 0004 and/or their figure 2. The prior art teaches the limitations of claim 6 in its figure 1 which the same as Applicant’s figure 2).
Regarding claim 7, and 38, Van Brunt teaches at least in figures 6A-7C:
wherein the semiconductor epitaxial structure comprises silicon carbide (the entire disclosure is directed to SiC. However, figure 27 explicitly shows this limitation).
Regarding claim 32,
Claim 1 teaches all of the limitations of claim 32 with the exception of:
wherein the doped region comprises a first elongated region and a second elongated region,
wherein the first elongated region has a first width and a first length that is greater than the first width when viewed in a plan view of the planar surface of the semiconductor substrate, and
wherein the second elongated region has a second width and a second length that is greater than the second width when viewed in the plan view of the planar surface of the semiconductor substrate;
wherein the first length of the first elongated region extends in a first direction when viewed in the plan view of the planar surface of the semiconductor substrate and the second length of the second elongated region extends in a second direction when viewed in the plan view of the planar surface of the semiconductor substrate,
However, the limitation is directed to the shape of the guard rings. The prior art in at least figure 7A-7C teaches this same shape.
Conclusion
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/VINCENT WALL/ Primary Examiner, Art Unit 2898
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