DETAILED ACTION
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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 2/2/2026 and 3/2/2026 has been entered.
Claims 1-9 and 11-13 are pending. Claim 10 has been canceled. Claims 12-13 have been withdrawn.
Drawings
The drawings are objected to under 37 CFR 1.83(a). The drawings must show every feature of the invention specified in the claims. Therefore, the plural “first parts” of the first portion of the epitaxial layer that are “being covered by the Schottky metal contacts” must be shown or the feature(s) canceled from the claim(s). FIG. 1 shows only one part of the first portion of the epitaxial layer that is covered by a Schottky metal contact. No new matter should be entered.
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.
Claim Objections
Claim 1 is objected to because of the following informalities: Claim 1 is missing a period “.” punctuation at the end. A claim must ends with a period. See MPEP 608.01(m). Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):
(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
The following is a quotation of the first paragraph of pre-AIA 35 U.S.C. 112:
The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor of carrying out his invention.
Claims 1-9 and 11 are rejected under 35 U.S.C. 112(a) or 35 U.S.C. 112 (pre-AIA ), first paragraph, as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor or a joint inventor, or for pre-AIA the inventor(s), at the time the application was filed, had possession of the claimed invention.
Applicant’s 3/2/2026 remark alleges the limitation “the epitaxial layer is of a first doping type” in claim 1 defines “the epitaxial layer, in its entirety, has a uniform doping type, that is, only one doping type” (page 10). Such interpretation lacks adequate written description. The epitaxial layer 2 as disclosed by applicant is initially of the first doping type. However, as shown in FIG. 4, second doping type pillars 3 are doped in the epitaxial layer 2. As shown in FIG. 6, second doping type wells 5 are further doped in the epitaxial layer 2. The epitaxial layer 2 of the final device structure comprises not first doping type, but also comprises second doping type in counter doped regions 3 and 5. The epitaxial layer 2 as disclosed does not “in its entirety, has a uniform doping type, that is, only one doping type” as alleged in Applicant’s remark. As such, the limitation “the epitaxial layer is of a first doping type”, if interpreted as alleged by Applicant, is not support by Applicant’s original disclosure.
Applicant’s 3/2/2026 remark further alleges the recitation to “Schottky metal contacts” in claim 1 is defined to mean “only the interface that makes Schottky contacts” (page 11). Such interpretation lacks adequate written description. Applicant discloses “Schottky metal contacts” 13 that “cover the first part of the top surface of each structural gate 12 and the first parts of the top surface of the epitaxial layer between the two structural gates 12” (¶ 64). The “Schottky metal contacts” 13 may be one or more of titanium, titanium nitride, and aluminum (¶ 70). However, Applicant’s original disclosure does not provide unequivocal written description for the presence Schottky contact barrier in interface with both the epitaxial layer and the gate structural gates. The original disclosure at best describes a metal contact formed of one or more of titanium, titanium nitride, and aluminum that makes Schottky contact with at least one of the regions the metal directly contacts, which may be at least one of the epitaxial layer or the gate structural gates. However, there is no positive recitation to Schottky contacts with both the epitaxial layer and the gate structural gates. As such, the term “Schottky metal contacts”, if interpreted as alleged by Applicant, is not support by Applicant’s original disclosure.
Other claims are rejected for depending on a rejected claim.
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.
Claims 1-9 and 11 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 pre-AIA the applicant regards as the invention.
Claim 1 reciting “the epitaxial layer is of a first doping type” renders the claim indefinite in light of interpretation as defined by Applicant in the 3/2/2026 Remark. As explained above, Applicant’s own disclosure fails to provide support for an epitaxial layer that “in its entirety, has a uniform doping type, that is, only one doping type”. Rather, the epitaxial layer 2 as disclosed does comprise counter doped regions (e.g. p-doped regions 3,5) having second doping type. Therefore, it is unclear if “the epitaxial layer is of a first doping type” is intended to mean an epitaxial layer that in its entirety has only one doping type as argued by Applicant, or more broadly referring to an epitaxial layer that is formed of a first doping type, but may incorporate further regions of second doping type. For the purpose of examination, the claimed “the epitaxial layer is of a first doping type” is understood to mean an epitaxial layer that is of a first doping type, but may also include regions of second doping type.
Claim 1 reciting “Schottky metal contacts” render the claim indefinite in light of interpretation as defined by Applicant in the 3/2/2026 Remark. As explained above, Applicant’s own disclosure fails to provide support for “Schottky metal contacts” forming Schottky contact barriers with both the first parts of the epitaxial layer and the first part of the structural gates. Therefore, it is unclear if “Schottky metal contacts” is intended to mean Schottky contact barrier at all contact interfaces of the metal contacts, or more broadly referring to metal contacts that are formed of metal and that form Schottky contact barrier in at least some interface. For the purpose of examination, the claimed “Schottky metal contacts” is understood to mean the metal contacts form Schottky contact barrier in at least one contact interface. The metal as a whole is considered to form “Schottky metal contacts” even if there exists portions of the metal that do not form Schottky contact barrier.
Claim 1 reciting “the first parts being covered by the Schottky metal contacts” renders the claim indefinite. The correspondence of the limitation is unclear. It is unclear the intended meaning is one of the first parts is covered by one of the Schottky metal contacts, or each of the first parts is covered by one of the Schottky metal contacts, or one of the first parts is covered by each of the Schottky metal contacts, or each of the first parts is covered by each of the Schottky metal contacts.
Claim 1 reciting “the second parts being covered by the insulating oxide layer” renders the claim indefinite. The correspondence of the limitation is unclear. It is unclear the intended meaning is each of the second parts is covered by the insulating oxide layer or one of the second parts is covered by the insulating oxide layer.
Claim 1 reciting “the trench is formed by etching the top surface of the first portion of the epitaxial layer” renders the claim indefinite due to unclear antecedent basis. Claim 1 recites “each of the structural gates comprises a trench”. Therefore, it is unclear if “the trench” formed by etching is intended to refer to “the trench of one of the structural gates” or “the trench of each of the structural gates”.
Claim 1 reciting “each of the structural gates comprises a top surface, which further comprises a first part and a second part, the first part being covered by the Schottky metal contacts, and the second part being covered by the insulating oxide layer” render the claim indefinite due to improper correspondence. Firstly, “the first part being covered by the Schottky metal contacts” in indefinite because it is unclear if the intended meaning is “the first part of each of the structural gates being covered by each of the Schottky metal contacts”, or “the first part of each of the structural gates being covered by one of the Schottky metal contacts”, or “the first part of one of the structural gates being covered by each of the Schottky metal contacts, or “the first part of one of the structural gates being covered by one of the Schottky metal contacts. Furthermore, “the second part being covered by the insulating oxide layer” is indefinite because it is unclear if the intended meaning is “the second part of one of the structural gates being covered by the insulating oxide layer” or “the second part of each of the structural gates being covered by the insulating oxide layer”.
Claim 2 reciting “a second portion of an insulating oxide layer” renders the claim indefinite for lacking proper antecedent basis. It is unclear if “an insulating oxide layer” is the same as “an insulating oxide layer” previously recited in claim 1, and how they may be related.
Claim 2 reciting “a second portion of a front metal layer” renders the claim indefinite. No “first portion of a front metal layer” is recited previously. It is unclear whether the “second portion of a front metal layer” implies the presence of “a first portion” of the front metal layer.
Claim 2 reciting “a second portion of a back metal layer” renders the claim indefinite. No “first portion of a back metal layer” is recited previously. It is unclear whether the “second portion of a back metal layer” implies the presence of “a first portion” of the back metal layer.
Claim 4 reciting “a first portion of the front metal layer” and “a first portion of the back metal layer” renders the claim for lacking antecedent basis. No “front metal layer” or “back metal layer” has been previously recited in claim 4 or claim 1.
Other claims are rejected for depending on a rejected claim.
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.
(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.
Claims 1, 2, and 4-7 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Darwish et al. US 2014/0252463 A1 (Darwish).
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In re claim 1, as best understood, Darwish discloses (e.g. FIGs. 2-21) a super-junction MOS device (FIG. 14, device having super-junctions formed by p-shields 150 and N-epi 101; FIG. 21 showing a specific integrated embodiment, ¶ 63) with an integrated TMBS structure 1490 (e.g. any of TMBS structure shown in FIGs. 2-12, ¶ 55), comprising:
a main body 1480 (e.g. FIGs. 15A-15G) and a TMBS structure 1490 (e.g. FIGs. 2-12),
wherein the main body comprises a plurality of cells 1480,
wherein the TMBS structure 1490 is connected in parallel with and integrated between at least two of the plurality of cells 1480, and
wherein the TMBS structure 1490 (FIGs. 2-13, or FIG. 21 showing an integrated embodiment) comprises:
a first portion (portion in the region of Schottky barrier diode 1490) of an epitaxial layer 101 (310,301,312 are all within n epi layer 101, ¶ 38) disposed on a surface of a first portion of a substrate 100;
two structural gates 944,1344 located in the epitaxial layer 101,310,301,312;
“Schottky metal contacts” (corresponding to lower contact portions of metal 103 including portions above n epi 1345,860,160,1660 and portion above structural gates 944,1344, each of these contact portions being a part of the same metal 103 that makes Schottky contacts; metal 103 is formed of aluminum (¶ 35) which is disclosed by Applicant as a material for the Schottky metal contacts; therefore, the metal 103 is considered a Schottky metal and the corresponding portions above the n-epi and gates are considered “Schottky metal contacts”); and
a first portion of an insulating oxide layer (including 940,1340 and oxide above 310);
wherein the first portion of the epitaxial layer has a top surface including first parts (parts of n- layer 101,310 top surface contacted by 160,860,1660) and second parts (parts of n- layer 101,310 top surface covered by an oxide, see FIGs. 12,14,21 annotated above) between the two structural gates, “the first parts being covered by the Schottky metal contacts, and the second parts being covered by the insulating oxide layer” (see FIGs. 12,14,21 annotated above);
wherein “the epitaxial layer 101 (including 310,301,312) is of a first doping type (n-type, ¶ 38)”;
wherein each of the structural gates 944,1344 comprises a trench, a gate oxide layer 140 formed on an inner surface of the trench, and a gate conductor 944,1344 filled in the trench, with the gate oxide layer 140 formed between the trench and the gate conductor 944,
wherein “the trench” is formed by etching the top surface of the first portion of the epitaxial layer 101 (in Schottky diode region),
wherein each of the structural gates 944,1344 comprises a top surface, which further comprises (see FIGs. 13A-13C) a first part (part contacting 1345) and a second part (part covered by 1340), “the first part (part under 1345) being covered by the Schottky metal contacts” (contact part 1345 ), and the second part (part under 1340) being covered by the insulating oxide layer (including 1340).
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In re claim 2, as best understood, Darwish discloses (e.g. FIGs. 14, 21 & 15A-15G) the super-junction MOS device as claimed in claim 1, wherein the main body 1480 (e.g. FIGs. 15B, 15E, 15G) further comprises:
a second portion of the substrate 100 (portion in the MOSFET region), wherein the substrate 100 is of the first doping (N) type;
a second portion of the epitaxial layer 101 (portion of n epi layer 101 in MOSFET region, including 310,301,312, ¶ 38) disposed on a surface of the second portion of the substrate 100;
a plurality of second pillars 150,550,1558 spaced apart and distributed in the epitaxial layer 101, wherein the plurality of second pillars 150,550,1558 is of a second doping (P) type, wherein pillar-like regions of the epitaxial layer 101 (regions of 301 between P regions 150,550,1558) between two of the plurality of second pillars 150,550,1558 are first pillars, wherein the first pillars (regions of 301 between P regions 150,550,1558) are of the first doping (N) type, and the second doping (P) type is different from the first doping (N) type;
a plurality of super-junction gates 1520 disposed in the first pillars (regions of 301 between P regions 150,550,1558) respectively, wherein each of the plurality of super-junction gates 1520 comprises a trench, a gate oxide layer formed on an inner surface of the trench, and wherein a gate conductor fills in the trench, wherein the gate oxide layer is formed between the trench and the gate conductor, and wherein the trench is formed by etching a top surface of the second portion of the epitaxial layer 101;
a plurality of wells 452, which are of the second doping (P) type, wherein one of the plurality of wells 452 is formed in the epitaxial layer 101 between every two adjacent super-junction gates 1520, and wherein a depth of one of the plurality of wells 452 is less than a depth of the trench of each of the plurality of super-junction gates 1520;
a plurality of source regions 1114, wherein one or more isolation regions 453 disposed in upper portions of the plurality of wells 452, wherein the plurality of source regions 1114 is of the first doping (N) type, wherein at least two of the source regions 1114 are on two sides of one of the one or more isolation regions 453 respectively, wherein each of the plurality of source regions 1114 has a top surface, which further comprises a first part (see FIG. 15E, part of N+ that physically contacts 103) and a second part (part of N+ that is separated from 103), wherein the first part of the top surface (part of N+ that physically contacts 103) is closer to the one of the one or more isolation region 453 (P+) than the second part (part of N+ that is separated from 103);
one or more sources (recessed portions of 103 contacting N+ source regions), wherein each of the one or more sources (recessed portions of 103) is disposed on a top surface of a corresponding one of the one or more isolation regions 453 and on the first part of the top surface (part of N+ that physically contacts 103) of one of the plurality of source regions 1114;
a second portion of “an insulating oxide layer” (oxide above gate 1520), disposed on the second part of the top surface (part of N+ that is separated from 103) of each of the plurality of source regions 1114 and on a top surface of each of the plurality of super-junction gates 1520;
“a second portion” of a front metal layer (planar upper portion of 103), disposed on a top surface of the insulating oxide layer and a top surface of each of the one or more sources (recessed portions of 103), wherein the front metal layer (planar upper portion of 103) inter-connects each of the one or more sources (recessed portions of 103); and
“a second portion” of a back metal layer 102, disposed on a surface of the substrate 100 away from the epitaxial layer 101.
In re claim 4, Darwish discloses (e.g. FIG. 14) the super-junction MOS device of claim 1,
wherein the substrate 100 is of a first doping (N) type; and
wherein the TMBS structure 1490 (FIGs. 2-13) comprises:
“a first portion of the front metal layer” (upper planar portion of 103), disposed on top surfaces of the Schottky metal contacts (lower portion of 103 including 1345,860, see FIGs. 11-13) and a top surface of the insulating oxide layer (including 940,1340 and oxide above 310) for connecting all the Schottky metal contacts (lower portion of 103 including 1345,860, see FIGs. 11-13); and
“a first portion of the back metal layer” 102, disposed on a surface of the substrate 100 away from the epitaxial layer 101,310,301,312.
In re claim 5, Darwish discloses (see FIG. 22) wherein a distance between the two structural gates 144 is set at from 0.5 µm to 10 µm (spacing between field plates 144 is shown to be ~0.5 µm to 1 µm depending on the vertical location), and a depth of each of the structural gates is from 1 µm to 5 µm (¶ 70, depth is 1 µm).
In re claims 6 and 7, Darwish discloses (FIGs. 2-21) wherein the first doping type is N type and the second doping type is P type.
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 3 is rejected under 35 U.S.C. 103 as being unpatentable over Darwish as applied to claim 2 above, and further in view of Saito et al. US 2010/0096692 A1 (Saito).
In re claim 3, Darwish discloses (e.g. FIGs. 15A-15E) wherein a dopant ion concentration of the one or more isolation regions 453 (P+) is higher than a dopant ion concentration of the plurality of wells 452 (P). Darwish discloses a dopant ion concentration of the plurality of second pillars 150 is about 5x1015cm-3. Darwish further discloses the P-shield regions 150 are provided to reduce the electric field (¶ 35). However, Darwish does not explicitly discloses the dopant ion concentration of the plurality of wells 452 is higher than a dopant ion concentration of the plurality of second pillars 150.
Saito discloses a power device (e.g. FIG. 1) comprising a trench MOS integrated with Schottky diode, wherein the device body comprises p-type pillars 4 alternating with n-type pillars 3 forming a super junction structure, wherein the p-type pillar 4 has a lower p-type impurity concentration than the p-type base layer 5 of the MOSFET to allow channel to be formed in the p-type pillars (¶ 33).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to form Darwish’s p-type pillars to have a dopant ion concentration that is lower than the p-type wells 452 to allow for channel formation in the p-type pillars as taught by Saito.
Claims 8-9 are rejected under 35 U.S.C. 103 as being unpatentable over Darwish as applied to claims 2 and 4 above, and further in view of Grivna et al. US 2015/0325567 A1 (Grivna).
In re claims 8 and 9, Darwish discloses the claimed invention including an epitaxial layer 101 includes n-type regions 310,301,312. Darwish does not explicitly discloses a thickness of the epitaxial layer is between 10 µm and 100 µm, and a resistivity of the epitaxial layer is from 0.1 ohm∙cm to 10 ohm∙cm.
However, Grivna discloses (FIGs. 6-11) a power device having n-type epitaxial layer 604,606,608 having a total thickness of, e.g. 8µm+1.6µm+1µm=10.6 µm, and a resistivity of 1.0 ohm∙cm (¶ 55). Grivna discloses the parameters as suitable for a device of desired breakdown voltage (¶ 55).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to form Darwish’s epitaxial layer 101 to have a thickness that is between 10 µm and 100 µm, and a resistivity of the epitaxial layer is from 0.1 ohm∙cm to 10 ohm∙cm, such as 10.6 µm and 1.0 ohm∙cm as taught by Grivna as suitable for a power device with desired device characteristics.
“[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” See MPEP 2144.05 II. In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955); see also Peterson, 315 F.3d at 1330, 65 USPQ2d at 1382; In re Hoeschele, 406 F.2d 1403, 160 USPQ 809 (CCPA 1969). For more recent cases applying this principle, see Merck & Co. Inc. v. Biocraft Lab. Inc., 874 F.2d 804, 10 USPQ2d 1843 (Fed. Cir.), cert. denied, 493 U.S. 975 (1989); In re Kulling, 897 F.2d 1147, 14 USPQ2d 1056 (Fed. Cir. 1990); and In re Geisler, 116 F.3d 1465, 43 USPQ2d 1362 (Fed. Cir. 1997); Smith v. Nichols, 88 U.S. 112, 118-19 (1874); In re Williams, 36 F.2d 436, 438 (CCPA 1929). See also KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 416 (2007).
Claim 11 is rejected under 35 U.S.C. 103 as being unpatentable over Darwish as applied to claim 2 above, and further in view of Sakakibara et al. US 2008/0246096 A1 (Sakakibara).
In re claim 11, Darwish discloses the claimed invention including the super-junction MOS device having the N+ doped substrate 100 and p-type pillars 150,550,1558 in the n type epitaxial layer. The claimed ion implantation dose from 1e12 ions/cm2 to 1e14 ions/cm2 and an implantation energy from 10 keV to 200 keV pertains to processing conditions for forming the doped substrate. No specific substrate has been claimed that would structurally distinguish over Darwish’s N+ substrate 100. In regard to the product by process language, since a "product by process" claim is directed to the product per se, no matter how actually made, In re Hirao and Sato et al., 190 USPQ 15 at 17 (CCPA 1976) (footnote 3). “[T]he lack of physical description in a product-by-process claim makes determination of the patentability of the claim more difficult, since in spite of the fact that the claim may recite only process limitations, it is the patentability of the product claimed and not of the recited process steps which must be established. We are therefore of the opinion that when the prior art discloses a product which reasonably appears to be either identical with or only slightly different than a product claimed in a product-by-process claim, a rejection based alternatively on either section 102 or section 103 of the statute is eminently fair and acceptable. As a practical matter, the Patent Office is not equipped to manufacture products by the myriad of processes put before it and then obtain prior art products and make physical comparisons therewith.” In re Brown, 459 F.2d 531, 535, 173 USPQ 685, 688 (CCPA 1972). See also In re Luck and Gainer, 177 USPQ 523 (CCPA 1973); In re Fessmann, 180 USPQ 324 (CCPA 1974); and In re Marosi et al., 218 USPQ 289 (CAFC 1983). It is the final product per se which must be determined for patentability in a "product by, all of" claim, and not the patentability of the process, and that an old or obvious product, whether claimed in "product by process" claims or not, is not patentable. Note that Applicant has the burden of proof in such cases, as the above case law makes clear. Even though product-by-process claims are limited by and defined by the process, determination of patentability is based upon the product itself. The patentability of a product does not depend on its method of production. If the product in product-by-process claim is the same as or obvious from a product of the prior art, the claim is unpatentable even though the prior product is made by a different process. In re Thorpe, 227 USPQ 964, 966 (Fed. Cir. 1985).
Darwish does not explicitly disclose a depth of one of the plurality of the second pillars 150,550,1558 is between 8 µm and 90 µm.
However, Sakakibara discloses (e.g. FIG. 17) an integrated super-junction MOS device having super-junction SJ structure comprising p columns 30 that extends a depth of about 1 µm to 100 µm (¶ 41), wherein the SJ structure is provided to reduce electric field in the device body (¶ 57).
Therefore, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to form Darwish’s p-type pillars 150,550,1558 to a desired depth, e.g. 8 µm and 90 µm, to obtain desired device characteristics, e.g. reduced electric field as taught by Sakakibara.
“[W]here the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” See MPEP 2144.05 II. In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955); see also Peterson, 315 F.3d at 1330, 65 USPQ2d at 1382; In re Hoeschele, 406 F.2d 1403, 160 USPQ 809 (CCPA 1969). For more recent cases applying this principle, see Merck & Co. Inc. v. Biocraft Lab. Inc., 874 F.2d 804, 10 USPQ2d 1843 (Fed. Cir.), cert. denied, 493 U.S. 975 (1989); In re Kulling, 897 F.2d 1147, 14 USPQ2d 1056 (Fed. Cir. 1990); and In re Geisler, 116 F.3d 1465, 43 USPQ2d 1362 (Fed. Cir. 1997); Smith v. Nichols, 88 U.S. 112, 118-19 (1874); In re Williams, 36 F.2d 436, 438 (CCPA 1929). See also KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398, 416 (2007).
Response to Arguments
Applicant's arguments filed 2/2/2026 and 3/2/2026 have been fully considered but they are not persuasive.
Applicant argues the epitaxial layer is of a first doping type and is different from Darwish’s p-type region 656 (2/2/2026 Remark, page 11; 3/2/2026 Remark, page 10). Applicant further argues 310 and 656 cannot teach first parts and second arts of the top surface of the epitaxial layer because they don’t belong to one layer (2/2/2026 Remark, page 11).
This is not persuasive. Darwish teaches 101 is an n-type epitaxial layer that includes n-type regions 310,301,312 (¶ 38). P-type regions 656 are further formed in the n-type epitaxial layer 101 by counter doping. Therefore, a top surface of the n-type epitaxial layer 101 includes n-doped regions 310 and p-type regions 656. As such, the first parts correspond to the parts of the top surface exposing n-doped region 310 of the epitaxial layer 101, while second parts correspond to the parts of the top surface exposing the p-doped region 656 of the epitaxial layer 101. The first parts being “covered” by the Schottky contact, and the second part being “covered” by the insulating oxide layer. Note the claim does not require the insulating oxide layer to contact the n-doped region of the epitaxial layer. Claim 1 only require second parts of the epitaxial layer top surface being “covered” by the insulating oxide layer. Such interpretation is consistent with Applicant’s disclosure to an epitaxial layer 2 that also includes p-type doped regions in different regions.
Furthermore, Darwish teaches in FIG. 21 parts of the n- doped region 310 of the epitaxial layer 101 directly contacts the overlying insulating oxide layer.
Applicant further argues metal 103 makes ohmic contact to 1344 and only makes Schottky contact at 160,860, thus failing to teach Schottky metal contacts covering the first part of the structural gates (2/2/2026 Remark, pages 11-12). Applicant further argues Schottky contacts must make Schottky contacts (3/2/2026 Remark, page 10).
This is not persuasive. Firstly, claim 1 does not positively recite any contact interface between the structural gate and the Schottky metal contacts. Rather, the claim merely recites the first part of the structural gates being “covered” by the Schottky metal contacts. Darwish teaches a metal layer 103 formed of aluminum (¶ 35) that makes Schottky contacts to at least the semiconductor body. Aluminum is a material for forming Schottky metal contacts as disclosed by Applicant. Therefore, the metal 103 is considered a Schottky metal and the portions contacting above gates 1344 are considered “Schottky metal contacts” that “cover” part of the gates.
Such interpretation is consistent with Applicant’s disclosure to Schottky metal contacts 13 formed from a Schottky metal layer that simultaneously “cover” part of the gate structures 12 and part of the epitaxial layer.
Conclusion
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/YU CHEN/Primary Examiner, Art Unit 2896
YU CHEN
Examiner
Art Unit 2896
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