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 I in the reply filed on 11/05/2025 is acknowledged. The traversal is on the ground(s) that claims 21-25 align with claims 1-15. This is not found persuasive because claims 1-15 does not have any limitation about first and second conductivity type, because of this claims 21-25 is mutually exclusive from claims 1-15.
The requirement is still deemed proper and is therefore made FINAL.
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) 1-6,8,10,12,14 is/are rejected under 35 U.S.C. 103 as being unpatentable over Losee et al (US Pub No. 20180337273).
With respect to claim 1, Losee et al discloses forming a source terminal (48,46,52,50,Fig.2), including: implanting, at a first face of a semiconductor body (top surface of 30), a doped region (46,54,52,50), and forming a metal layer (48,para 31) on the first face of the semiconductor body (Fig.1) and electrically coupled to the doped region (Fig.1); and forming a drain terminal (40) at a second face of the semiconductor body (bottom side, Fig.2) that is opposite the first face along a direction ( y direction), wherein the implanting the doped region includes forming a first sub-region having a first doping concentration (Para 46) and a first maximum depth (Fig.2) in the semiconductor body (Fig.2), and forming a second sub-region (50,52,54) having a second doping concentration (Para 46,para 31) and a second maximum depth (Fig.2) in the semiconductor body (Fig.2), wherein at least one of the second doping level and the second maximum depth has a value which is higher than a respective value of the first doping level (Fig.2,Para 46,para 31,Fig.6) and the first maximum depth (Fig.2), and the forming said metal layer includes forming the metal layer in electrical contact with the source terminal (Fig.2) exclusively through said second sub-region (Fig.2), the metal layer being in direct physical contact with the source terminal at only the second sub-region of the source terminal (Fig.2). Losee et al discloses that region 52 is implanted (Para 44), but it does not explicitly disclose wherein the source terminal is implanted, However, it would have been obvious to one of ordinary skill in the art at the time of the filing of the invention to modify Losee et al such that the source terminal is entirely implanted in order to make a precise and accurate source regions, thereby reducing device defect.
With respect to claim 2, Losee et al discloses wherein: the first doping concentration has a value in a range of 1-1018-1.1020 atoms/cm3 (Para 46), the second doping concentration is higher than the first doping concentration and has a value in a range of 1-1019-1.1020 atoms/cm3 (Para 31,46). However, Losee et al does not explicitly disclose the first maximum depth has a value in a range of 0.2-0.4 um, and the second maximum depth has a value in a range of 0.6-0.7 um. However, "[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." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). Furthermore, it would have been obvious to one of ordinary skill in the art at the time of the filing of the invention to modify Losee et al such that the first maximum depth has a value in a range of 0.2-0.4 um, and the second maximum depth has a value in a range of 0.6-0.7 um, in order to minimize the size of the device, while it would not jeopardize optimal function of the device.
With respect to claim 3, Losee et al discloses wherein: the first doping concentration has a value in a range of 1-1018-2.1019 atoms/cm3, (Para 46) the second doping concentration is higher than the first doping concentration and has a value in a range of 1-1019-1.1020 atoms/cm3,(Para 46,para 31). However, Losee et al does not explicitly disclose and the first maximum depth is equal to the second maximum depth in a range of 0.2-0.4 um. However, Losee et al does not explicitly disclose the first maximum depth has a value in a range of 0.2-0.4 um. However, "[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." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). Furthermore, it would have been obvious to one of ordinary skill in the art at the time of the filing of the invention to modify Losee et al such that the first maximum depth has a value in a range of 0.2-0.4 um, in order to minimize the size of the device, while it would not jeopardize optimal function of the device.
With respect to claim 4, Losee et al discloses wherein: the first doping concentration has a value in a range of 1-1019-1.1020 atoms/cm3, (Para 46). However, Losee et al does not explicitly disclose the second doping concentration is equal to the first doping concentration , the first maximum depth has a value in a range of 0.1-0.2 um, and the second maximum depth is higher than the first maximum depth and has a value in a range of 0.2-0.4 um. However, Losee et al does not explicitly disclose the first maximum depth has a value in a range of 0.2-0.4 um. However, "[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." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). Furthermore, it would have been obvious to one of ordinary skill in the art at the time of the filing of the invention to Modify Losee et al such that e the second doping concentration is equal to the first doping concentration , the first maximum depth has a value in a range of 0.1-0.2 um, and the second maximum depth is higher than the first maximum depth and has a value in a range of 0.2-0.4 um in order to reduce the fabrication cost.
With respect to claim 5, Losee et al discloses the first doping concentration has a value in a range of 1-1018-2.1019 atoms/cm3, (Para 46) the second doping concentration is higher than the first doping concentration (Para 31,para 46) and has a value in a range of 1-1019-1.1020 atoms/cm3, (Para 46). However, Losee et al does not explicitly disclose the first maximum depth has a value in a range of 0.1-0.4 um, and the second maximum depth has a value in a range of 0.2-0.4 um. However, "[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." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). Furthermore, it would have been obvious to one of ordinary skill in the art at the time of the filing of the invention to Modify Losee et al such that the first maximum depth has a value in a range of 0.1-0.4 um, in order to minimize the size of the device, while it would not jeopardize optimal function of the device.
With respect to claim 6. Losee et al discloses: the first doping concentration has a value in a range of 1-1018-2.1019 atoms/cm3, (Para 46) the second doping concentration is higher than the first doping concentration and has a value in a range of 1-1019-1.1020 atoms/cm3, (Para 46). However, it does not explicitly disclose the first maximum depth has a value in a range of 0.1-0.4 um, and the second maximum depth has a value in a range of 0.6-0.7 um. However, "[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." In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955). Furthermore, it would have been obvious to one of ordinary skill in the art at the time of the filing of the invention to modify Losee et al such that the first maximum depth has a value in a range of 0.1-0.4 um, and the second maximum depth has a value in a range of 0.6-0.7 um, in order to minimize the size of the device, while it would not jeopardize optimal function of the device.
With respect to claim 8, Losee et al discloses wherein the first sub-region and the second sub-region are formed in direct reciprocal electrical contact (Para 31,46).
With respect to claim 10, the arts cited above do not explicitly disclose wherein said semiconductor body is of 4H-SiC. However, it would have been obvious to one of ordinary skill in the art at the time of the filing of the invention to modify the arts cited above such that semiconductor body is of 4H-SiC, because of it’s higher bandgap it would be ideal for high voltage application.
With respect to claim 12, Losee et al discloses forming a second metal layer (40) at a second surface of the semiconductor body (bottom surface) that is opposite the first surface. However, Losee et al does not explicitly disclose that layer 40 which is an electrode is made out of metal. However, it would have been obvious to one of ordinary skill in the art at the time of the filing of the invention to modify Losee et al such that the electrode for the drain is made out of metal, because of it’s high conductivity.
With respect to claim 14, Losee et al does not explicitly disclose wherein forming the doped region, includes implanting the doped region in the semiconductor body. On the other hand, it would have been obvious to one of ordinary skill in the art at the time of the filing of the invention to modify Losee et al such that wherein forming the doped region, includes implanting the doped region in the semiconductor body, in order to make a precise source region, thereby reducing product defect.
Claim(s) 9 is/are rejected under 35 U.S.C. 103 as being unpatentable over Losee et al (US Pub No. 20180337273), in view of Uehara et al (US Pub No. 20170077285).
With respect to claim 9, Loseeet al discloses further comprising forming a gate structure on the first face of the semiconductor body (58,56), the forming the gate structure including: forming a gate dielectric layer (58); forming a metal gate layer on the gate dielectric layer (56). However, Losee et al does not explicitly disclose and completely surrounding an upper surface and lateral surfaces of the metal gate layer with an insulating layer, said gate structure completely covering the first sub-region. On the other hand, Uehara et al discloses completely surrounding an upper surface and lateral surfaces of the metal gate layer (20,Fig.1) with an insulating layer (22). It would have been obvious to one of ordinary skill in the art at the time of the filing of the invention to modify the Losee et al according to the teachings of the Uehara et al such that an upper surface and lateral surfaces of the metal gate layer is surrounded by an insulating layer in order to protect the gate layer from unwanted etching during fabrication processes. However, the arts cited above do not explicitly disclose said gate structure completely covering the first subregion. On the other hand, it would have been obvious to one of ordinary skill in the art at the time of the filing of the invention to modify the arts cited above such that said gate structure completely covering the first subregion, in order to protect the gate electrode from the unwanted capacitance from the source contact properly.
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)(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.
Claim(s) 11,13 is/are rejected under 35 U.S.C. 102(a)(2) as being anticipated by Losee et al (US Pub No. 20180337273).
With respect to claim 11, Losee et al discloses forming a doped region (46,50,54,52,Fig.2) at a first surface of a semiconductor body (top surface of 30), including: forming a first sub-region having a first doping concentration (Para 46,46), the first sub-region extending into the semiconductor body from the first surface to a first depth (Fig.2); and forming a second sub-region having a second doping concentration (50,52,54, para 31,para 46), the second sub-region extending into the semiconductor body from the first surface to a second depth (Fig.2), wherein the second depth is greater than the first depth (Fig.2); and forming a first metal layer (48) on the first surface of the semiconductor body and electrically coupled to the doped region (Fig.2).
With respect to claim 13, Losee et al discloses, wherein the first metal layer directly contacts only the second sub-region of the doped region (Fig.2).
Allowable Subject Matter
Claims 7,15 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
Conclusion
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/ALI NARAGHI/Primary Examiner, Art Unit 2817