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and the fee set forth in 37 CFR 1.17(e) has been timely paid, the finality of the previous Office action has been withdrawn pursuant to 37 CFR 1.114.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 July 13, 2026 has been entered.
Status of the Claims
Amendment filed July 26, 2026 is acknowledged. Claim 1 has been amended. Claims 1-10 are pending.
Action on merits of claims 1-10 follows.
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 1-10 are rejected under 35 U.S.C. 103 as being unpatentable over SAITO et al. (US. Pub. No. 2007/0138543) of record, in view of TAMAKI et al. (US. Pub. No. 2011/0115033).
With respect to claim 1, SAITO ‘543 teaches a semiconductor device substantially as claimed including:
a first semiconductor layer (2) having an N-type of conductivity; and
a second semiconductor layer (12) that is formed on the first semiconductor layer (2), and including an active region, a frame region, and a termination region,
wherein the active region comprises a plurality of first P-pillars (34) and first N-pillars (33) formed between the plurality of first P-pillars (34),
the frame region comprises an upper frame region (5) formed to extend in a first direction while having a P-type of conductivity, and a lower frame region that is formed below the upper frame region (5) and including a plurality of second P-pillars (34) and second N-pillars (33) formed between the plurality of second P-pillars (34), and
the termination region comprises an upper termination region (17) that extends in the first direction while having the P-type of conductivity, a middle termination region having the N-type of conductivity and formed below the upper termination region (17), and a lower termination region formed below the middle termination region and including a plurality of third P-pillars (34) and third N-pillars (34) formed between the plurality of third P-pillars (34),
wherein the upper termination region (17) comprises an area disposed within the upper termination region,
wherein the area is disposed in the upper termination region (17) above the middle termination region and the lower termination region, and
wherein the active region further comprises P body regions (5) and surface N regions (33) alternately arranged in the active region, each of the P body regions (5) includes an N+ region (6), and an outermost one of the surface N regions (33) is disposed between the N+ region (6) and the upper frame region (17) along the first direction. (See FIG. 20).
Thus, SAITO is shown to teach all the features of the claim with the exception of explicitly disclosing the upper termination region comprises a plurality of segmentation area; and each of the P body regions includes a P+ region.
However, TAMAKI teaches a semiconductor device including:
a termination region (4b) comprises an upper termination region (8) that extends in the first direction while having the P-type of conductivity, a middle termination region having the N-type of conductivity and formed below the upper termination region (8), and a lower termination region formed below the middle termination region and including a plurality of third P-pillars (6b) and third N-pillars (1e) formed between the plurality of third P-pillars (6b),
wherein the upper termination region (8) comprises a plurality of segmentation areas disposed within the upper termination region (8), the plurality of segmentation areas having a first segmentation area (8a), at least one intermediate segmentation are (8b), and a last segmentation area (8c) along the first direction,
wherein the plurality of segmentation areas (8a-c) are disposed in the upper termination region (8) above the middle termination region, and
wherein an impurity concentration of the first segmentation area (8a) is the highest, an impurity concentration of each of the at least one intermediate segmentation area (8b) is lower than that of the first segmentation area (8a), and an impurity concentration of the last segmentation area (8c) is the lowest, and
wherein active region further comprises P body regions (7) and surface N regions (1e) alternately arranged in the active region, each of the P body regions (7) includes a P+ region (15) and an N+ region (21), and an outermost one of the surface N regions (1e) is disposed between the N+ region (21) and the upper frame region (8) along the first direction. (See FIG. 22).
Therefore, it would have been obvious to one having ordinary skill in the art at the time of invention was made to form the upper termination region of SAITO comprising the plurality of segmentation area as taught by TAMAKI to prevent a variation in breakdown voltage caused by charge imbalance, and the P+ region to reduce contact resistance.
With respect to claim 2, the entire lower termination region of SAITO is covered by the upper termination region (17).
With respect to claim 3, the middle termination region and the upper termination region (17) of SAITO are sequentially formed on the third P-pillar (34).
With respect to claim 4, the second P-pillar (34) of SAITO is connected to the top surface of the second semiconductor layer (12) through the upper frame region (5).
With respect to claim 5, the third P-pillar (34) of SAITO is distanced from the top surface of the second semiconductor layer (12).
With respect to claim 6, the top surface of the middle termination region of SAITO is distanced from the top surface of the second semiconductor layer (12).
With respect to claim 7, the middle termination region of SAITO is connected with at least one of the plurality of third N-pillars (33) of the lower termination region.
With respect to claim 8, the upper termination region (17) of SAITO is connected with the upper frame region (5).
With respect to claim 9, the upper frame region (5) of SAITO is connected with at least one of the plurality of second P-pillars (34) of the lower frame region.
With respect to claim 10, impurity concentration of the upper frame region (5) of SAITO is higher than that of the upper termination region (17).
Response to Arguments
Applicant’s arguments with respect to amended claim 1 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Conclusion
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/ANH D MAI/Primary Examiner, Art Unit 2893
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