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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 05/14/2026 has been entered.
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.
Claims 1 and 26 are rejected under 35 U.S.C. 103 as being unpatentable over Maegawa et al. (US 20200141024 A1) hereinafter “Maegawa” in view of Kadono et al. (US 20200203418 A1) hereinafter “Kadono” and Mueller et al. (US 20200240039 A1) hereinafter “Mueller.”
Regarding Claim 1, Figure 1 of Maegawa teaches: An epitaxial wafer (Paragraph 0091) of 300 mm in diameter (Paragraph 0091) comprising: a silicon substrate (10) doped with phosphorus (Paragraph 0089) and having a resistivity of 0.8 mΩ-cm or more and 1.0 mΩ-cm or less; an epitaxial layer (Paragraph 0091) on the silicon substrate; and a boundary (inherent) between the epitaxial layer and the silicon substrate
In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists, MPEP 2144.05, In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976). In the instant case, the claimed range, 0.6 mΩ-cm or more and 0.9 mΩ-cm overlaps the range of Maegawa, 0.8 mΩ-cm or more and 1.0 mΩ-cm.
Maegawa does not teach: wherein the silicon substrate has a carbon concentration in a range of 3.5 x 1015 atoms/cm3or more to 5.0 x 1017 atoms/cm3 at about center of the silicon substrate in a depth direction.
Figure 4 of Kadono teaches: a silicon wafer (Paragraph 0019) wherein the silicon wafer has a carbon concentration in a range of 1.0 x 1015 atoms/cm3or more to 1.0 x 1017 atoms/cm3 at about center of the silicon substrate in a depth direction (Figure 4).
It would be obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have the silicon substrate has a carbon concentration in a range of 3.5 x 1015 atoms/cm3or more to 5.0 x 1017 atoms/cm3 at about center of the silicon substrate in a depth direction because Kadono teaches this range of carbon concentration in a silicon wafer can prevent the formation of dislocations (Kadono Paragraph 0046).
Furthermore, in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists, MPEP 2144.05, In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976). In the instant case, the claimed range, 3.5 x 1015 atoms/cm3or more to 5.0 x 1017 atoms/cm3 overlaps the range of Kadono, 1.0 x 1015 atoms/cm3or more to 1.0 x 1017 atoms/cm3.
Maegawa does not teach: an oxygen concentration in the silicon substrate in a range of 4.0 x 1017 atoms/cm3 or more and 8.0 x 1017 atoms/cm3 or less (Paragraph 0030).
Mueller teaches: a silicon wafer (Paragraph 0030) with an oxygen concentration in a range of 4.5 x 1017 atoms/cm3 to 5.5 x 1017 atoms/cm3.
It would be obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have an oxygen concentration in the silicon substrate in a range of 4.0 x 1017 atoms/cm3 or more and 8.0 x 1017 atoms/cm3 or less because Mueller teaches an oxygen concentration in a range of 4.5 x 1017 atoms/cm3 to 5.5 x 1017 atoms/cm3 has sufficient BMDs developed in the interior of the silicon wafer and octahedral oxygen precipitates can be eliminated sufficiently (Mueller Paragraph 0030).
Further, in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists, MPEP 2144.05, In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976). In the instant case, the claimed range, 4.0 x 1017 atoms/cm3 or more and 8.0 x 1017 atoms/cm3 overlaps the range of Mueller, 4.5 x 1017 atoms/cm3 to 5.5 x 1017 atoms/cm3.
Regarding Claim 21, Figure 1 of Maegawa teaches: A silicon wafer (Paragraph 0091) doped with phosphorus (Paragraph 0089) having a diameter of 300 mm (Paragraph 0091) having a resistivity of 0.8 mΩ-cm or more and 1.0 mΩ-cm or less;
In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists, MPEP 2144.05, In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976). In the instant case, the claimed range, 0.6 mΩ-cm or more and 0.9 mΩ-cm overlaps the range of Maegawa, 0.8 mΩ-cm or more and 1.0 mΩ-cm.
Maegawa does not teach: a carbon concentration in a range of 3.5 x 1015 atoms/cm3or more to 5.0 x 1017 atoms/cm3 at about center of the silicon wafer in a depth direction.
Figure 4 of Kadono teaches: a silicon wafer (Paragraph 0019) wherein the silicon wafer has a carbon concentration in a range of 1.0 x 1015 atoms/cm3or more to 1.0 x 1017 atoms/cm3 at about center of the silicon substrate in a depth direction (Figure 4).
It would be obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have a carbon concentration in a range of 3.5 x 1015 atoms/cm3or more to 5.0 x 1017 atoms/cm3 at about center of the silicon wafer in a depth direction because Kadono teaches this range of carbon concentration in a silicon wafer can prevent the formation of dislocations (Kadono Paragraph 0046).
Furthermore, in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists, MPEP 2144.05, In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976). In the instant case, the claimed range, 3.5 x 1015 atoms/cm3or more to 5.0 x 1017 atoms/cm3 overlaps the range of Kadono, 1.0 x 1015 atoms/cm3or more to 1.0 x 1017 atoms/cm3.
Maegawa does not teach: an oxygen concentration in the silicon substrate in a range of 4.0 x 1017 atoms/cm3 to 10 x 1017 atoms/cm3
Mueller teaches: a silicon wafer (Paragraph 0030) with an oxygen concentration in a range of 4.5 x 1017 atoms/cm3 to 5.5 x 1017 atoms/cm3 (Paragraph 0030)
It would be obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have an oxygen concentration in the silicon substrate in a range of 4.0 x 1017 atoms/cm3 or more and 8.0 x 1017 atoms/cm3 or less because Mueller teaches an oxygen concentration in a range of 4.5 x 1017 atoms/cm3 to 5.5 x 1017 atoms/cm3 has sufficient BMDs developed in the interior of the silicon wafer and octahedral oxygen precipitates can be eliminated sufficiently (Mueller Paragraph 0030).
Further, in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists, MPEP 2144.05, In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976). In the instant case, the claimed range, 4.0 x 1017 atoms/cm3 or more and 8.0 x 1017 atoms/cm3 overlaps the range of Mueller, 4.5 x 1017 atoms/cm3 to 5.5 x 1017 atoms/cm3.
Claims 6-7 are rejected under 35 U.S.C. 103 as being unpatentable over Maegawa et al. (US 20200141024 A1) hereinafter “Maegawa” in view of Kadono et al. (US 20200203418 A1) hereinafter “Kadono,” Mueller et al. (US 20200240039 A1) hereinafter “Mueller,” and Koike (US 20070089666 A1) hereinafter “Koike”.
Regarding Claim 6, the combination of Maegawa, Kadono, and Mueller teaches all of the limitations of the claimed invention as stated above.
Maegawa does not teach: a top surface of the epitaxial layer contains 130 or fewer light point defects (LPDs) of 0.09 pm or more in size.
Table 1 of Koike teaches: a silicon substrate wherein the epitaxial defect (light point defects) density is lower than 10 per substrate (Paragraph 0068).
It would be obvious to one of ordinary skill in the art to form the epitaxial layer to have a top surface of the epitaxial layer contains 130 or fewer light point defects (LPDs) of 0.09 pm or more in size because Koike teaches light point defects cause an increase in leak current and shortening of carrier lifetime (Koike Paragraph 0002).
Regarding Claim 7, the combination of Maegawa, Kadono, and Mueller teaches all of the limitations of the claimed invention as stated above.
Maegawa does not teach: a top surface of the epitaxial layer contains 100 or fewer LPDs of 0.09 pm or more in size.
Table 1 of Koike teaches: a silicon substrate wherein the epitaxial defect (light point defects) density is lower than 10 per substrate (Paragraph 0068).
It would be obvious to one of ordinary skill in the art to form the epitaxial layer to have a top surface of the epitaxial layer contains 100 or fewer light point defects (LPDs) of 0.09 pm or more in size because Koike teaches light point defects cause an increase in leak current and shortening of carrier lifetime (Koike Paragraph 0002).
Claims 10 and 28 are rejected under 35 U.S.C. 103 as being unpatentable over Maegawa et al. (US 20200141024 A1) hereinafter “Maegawa” in view of Kadono et al. (US 20200203418 A1) hereinafter “Kadono,” Mueller et al. (US 20200240039 A1) hereinafter “Mueller,” and Fujikawa et al. (US 6261362 B1) hereinafter “Fujikawa.”
Regarding Claim 10, the combination of Maegawa, Kadono, and Mueller teaches all of the limitations of the claimed invention as stated above.
Maegawa does not teach: the silicon substrate is substantially free of crystal-originated particles
Fujikawa teaches: a silicon wafer (Column 1/Line 13) is substantially free of crystal-originated particles (Column 3/Lines 20-22).
It would be obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have the silicon substrate is substantially free of crystal-originated particles because Fujikawa teaches epitaxial silicon wafers with extremely low crystal-originated particles can be manufactured to be high-quality epitaxial wafers with good yield (Fujikawa Column 4/ Lines 20-39).
Regarding Claim 28, the combination of Maegawa, Kadono, and Mueller teaches all of the limitations of the claimed invention as stated above.
Maegawa does not teach: the silicon wafer is substantially free of crystal-originated particles.
Fujikawa teaches: a silicon wafer (Column 1/Line 13) is substantially free of crystal-originated particles (Column 3/Lines 20-22).
It would be obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have the silicon substrate is substantially free of crystal-originated particles because Fujikawa teaches epitaxial silicon wafers with extremely low crystal-originated particles can be manufactured to be high-quality epitaxial wafers with good yield (Fujikawa Column 4/ Lines 20-39).
Claims 46-47 are rejected under 35 U.S.C. 103 as being unpatentable over Maegawa et al. (US 20200141024 A1) hereinafter “Maegawa” in view of Kadono et al. (US 20200203418 A1) hereinafter “Kadono”.
Regarding Claim 46, Figure 1 of Maegawa teaches: An epitaxial wafer (Paragraph 0091) of 300 mm in diameter (Paragraph 0091) comprising: a silicon substrate (10) doped with phosphorus (Paragraph 0089) and having a resistivity of 0.8 mΩ-cm or more and 1.0 mΩ-cm or less; an epitaxial layer (Paragraph 0091) on the silicon substrate; and a boundary (inherent) between the epitaxial layer and the silicon substrate
In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists, MPEP 2144.05, In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976). In the instant case, the claimed range, 0.6 mΩ-cm or more and 0.9 mΩ-cm overlaps the range of Maegawa, 0.8 mΩ-cm or more and 1.0 mΩ-cm.
Maegawa does not teach: wherein the silicon substrate has a carbon concentration in a range of 3.5 x 1015 atoms/cm3or more to 5.0 x 1017 atoms/cm3 at about center of the silicon substrate in a depth direction.
Figure 4 of Kadono teaches: a silicon wafer (Paragraph 0019) wherein the silicon wafer has a carbon concentration in a range of 1.0 x 1015 atoms/cm3or more to 1.0 x 1017 atoms/cm3 at about center of the silicon substrate in a depth direction (Figure 4).
It would be obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have the silicon substrate has a carbon concentration in a range of 3.5 x 1015 atoms/cm3or more to 5.0 x 1017 atoms/cm3 at about center of the silicon substrate in a depth direction because Kadono teaches this range of carbon concentration in a silicon wafer can prevent the formation of dislocations (Kadono Paragraph 0046).
Furthermore, in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists, MPEP 2144.05, In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976). In the instant case, the claimed range, 3.5 x 1015 atoms/cm3or more to 5.0 x 1017 atoms/cm3 overlaps the range of Kadono, 1.0 x 1015 atoms/cm3or more to 1.0 x 1017 atoms/cm3.
Maegawa does not teach: an oxygen concentration in the silicon substrate in a range of 4.0 x 1017 atoms/cm3 to 9.0 x 1017 atoms/cm3
Figure 4 of Kadono teaches: an oxygen concentration in the silicon substrate in a range of 9.0 x 1017 atoms/cm3 to 18 x 1017 atoms/cm3 (Paragraph 0048)
It would be obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have an oxygen concentration in the silicon substrate in a range of 9.0 x 1017 atoms/cm3 to 18 x 1017 atoms/cm3 because Kadono teaches an oxygen concentration as low as 9.0 x 1017 atoms/cm3 suppresses epitaxial defects (Kadono Paragraph 0048).
Furthermore, in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists, MPEP 2144.05, In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976). In the instant case, the claimed range, 4.0 x 1017 atoms/cm3 to 9.0 x 1017 atoms/cm3 overlaps the range of Maegawa, 9.0 x 1017 atoms/cm3 to 18 x 1017 atoms/cm3.
Regarding Claim 47, Figure 1 of Maegawa teaches: A silicon wafer (Paragraph 0091) doped with phosphorus (Paragraph 0089) having a diameter of 300 mm (Paragraph 0091) having a resistivity of 0.8 mΩ-cm or more and 1.0 mΩ-cm or less;
In the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists, MPEP 2144.05, In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976). In the instant case, the claimed range, 0.6 mΩ-cm or more and 0.9 mΩ-cm overlaps the range of Maegawa, 0.8 mΩ-cm or more and 1.0 mΩ-cm.
Maegawa does not teach: a carbon concentration in a range of 3.5 x 1015 atoms/cm3or more to 5.0 x 1017 atoms/cm3 at about center of the silicon wafer in a depth direction.
Figure 4 of Kadono teaches: a silicon wafer (Paragraph 0019) wherein the silicon wafer has a carbon concentration in a range of 1.0 x 1015 atoms/cm3or more to 1.0 x 1017 atoms/cm3 at about center of the silicon substrate in a depth direction (Figure 4).
It would be obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have a carbon concentration in a range of 3.5 x 1015 atoms/cm3or more to 5.0 x 1017 atoms/cm3 at about center of the silicon wafer in a depth direction because Kadono teaches this range of carbon concentration in a silicon wafer can prevent the formation of dislocations (Kadono Paragraph 0046).
Furthermore, in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists, MPEP 2144.05, In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976). In the instant case, the claimed range, 3.5 x 1015 atoms/cm3or more to 5.0 x 1017 atoms/cm3 overlaps the range of Kadono, 1.0 x 1015 atoms/cm3or more to 1.0 x 1017 atoms/cm3.
Maegawa does not teach: an oxygen concentration in the silicon substrate in a range of 4.0 x 1017 atoms/cm3 to 9.0 x 1017 atoms/cm3
Figure 4 of Kadono teaches: an oxygen concentration in the silicon substrate in a range of 9.0 x 1017 atoms/cm3 to 18 x 1017 atoms/cm3 (Paragraph 0048)
It would be obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to have an oxygen concentration in the silicon substrate in a range of 9.0 x 1017 atoms/cm3 to 18 x 1017 atoms/cm3 because Kadono teaches an oxygen concentration as low as 9.0 x 1017 atoms/cm3 suppresses epitaxial defects (Kadono Paragraph 0048).
Furthermore, in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists, MPEP 2144.05, In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976). In the instant case, the claimed range, 4.0 x 1017 atoms/cm3 to 9.0 x 1017 atoms/cm3 overlaps the range of Maegawa, 9.0 x 1017 atoms/cm3 to 18 x 1017 atoms/cm3.
Allowable Subject Matter
Claims 11-12, 16-20, and 29-37 are allowed.
The following is an examiner’s statement of reasons for allowance:
Regarding Claim 11, the prior art of record does not teach, suggest, or motivate one having ordinary skill in the art to have one of the following three conditions is satisfied:(i) the low carbon concentration layer in the silicon substrate is within about 5 µm of the boundary, and a carbon concentration in the low carbon concentration layer is decreased by 10% or more compared with the carbon concentration at about the center of the silicon substrate in the depth direction, or (ii) the low carbon concentration layer in the silicon substrate is within about 8 µm of the boundary, and a carbon concentration in the low carbon concentration layer is decreased by 10% or more compared with the carbon concentration at about the center of the silicon substrate in the depth direction, or (iii) the low carbon concentration layer in the silicon substrate is within about 15 µm of the boundary, and a carbon concentration in the low carbon concentration layer is decreased by 10% or more compared with the carbon concentration at about the center of the silicon substrate in the depth direction along with all of the limitations of Claim 11. Claims 12 and 16-20 are also allowable as they depend from and include all of the limitations of the claimed invention.
Regarding Claim 29, the prior art of record does not teach, suggest, or motivate one having ordinary skill in the art to have a carbon concentration in a region of the silicon substrate between the boundary and a position about 5 µm to 15 µm from the boundary is decreased by 10% or more compared with the carbon concentration at about the center of the silicon substrate in the depth direction along with the other limitations of Claim 29. Claims 30-33 are also allowable as they depend from and include all of the limitations of the allowable Claim 29.
Regarding Claim 34, the prior art of record does not teach, suggest, or motivate one having ordinary skill in the art to have a carbon concentration in a region of the silicon wafer between the top surface and a position about 5 µm to 15 µm from the top surface is decreased by 10% or more compared with the carbon concentration at about the center of the silicon wafer in the depth direction along with the other limitations of Claim 34. Claims 35-37 are also allowable as they depend from and include all of the limitations of allowable Claim 34.
Any comments considered necessary by applicant must be submitted no later than the payment of the issue fee and, to avoid processing delays, should preferably accompany the issue fee. Such submissions should be clearly labeled “Comments on Statement of Reasons for Allowance.”
Response to Arguments
Applicant’s arguments, see Applicant’s Remarks, filed 05/14/2026, with respect to the rejections of Claims 1 and 21 under 35 U.S.C. 103 have been fully considered and are persuasive. Therefore, the rejection has been withdrawn. However, upon further consideration, a new ground(s) of rejection is made in view of Maegawa, Kadono, and Mueller.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Halee Cramer whose telephone number is (571)270-1641. The examiner can normally be reached Monday - Friday 7:30am - 4:30pm.
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/HALEE CRAMER/Examiner, Art Unit 2891
/MATTHEW C LANDAU/Supervisory Patent Examiner, Art Unit 2891
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