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 .
Information Disclosure Statement
The information disclosure statement (IDS) submitted on 11/21/2023 and 11/29/2023 are in compliance with the provisions of 37 CFR 1.97. Accordingly, the information disclosure statement is being considered by the examiner.
Specification
The title of the invention is not descriptive. A new title is required that is clearly indicative of the invention to which the claims are directed.
Claim Rejections - 35 USC § 102
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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 13, 15, 17, 19, 22 and 24 are rejected under 35 U.S.C. 102 (a)(2) as being anticipated by Chang. (US-6392273-B1, hereinafter Chang),
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Regarding Claim 13.
Chang teaches in Fig.2 and in related text A vertical field effect transistor structure, comprising:
a semiconductor body including a first connecting zone (#100) and a second connecting zone (#108) of a first conductivity type (N-type);
a channel zone (#106) of the first conductivity type, or of a second conductivity type (type P) which is complementary to the first conductivity type, the channel being arranged between the first and the second connecting zones;
a plurality of trenches(#20 trench gate structure) extending into the semiconductor body, the trenches reaching from the second connecting zone (#108) through the channel zone, into the first connecting zone (#100) and forming fins of the channel zone and the second connecting zone;
a control electrode (Fig.1 #24) arranged in the trenches, the electrode being adjacent to the channel zone (#106) and insulated (#22) from the semiconductor body;
a reverse current path connected between the first and second connecting zones (#100, #108) and parallel to the channel zone (#106), the reverse current path including at least one p-n junction and being configured to conduct when a threshold voltage applied between the first and second connecting zones is reached;
wherein the semiconductor body includes a respective doped zone (Fig.5a. #130 or Fig. 6 #240) of the second conductivity type (P-type) in the first connecting zone (#100) below the trenches ;
wherein the fins include body connecting regions (#116/#114/#240) of the second conductivity type (P-type) which electrically contact the channel zone (#106) and the second connecting zone; and
wherein the body connecting regions (#116/#114/#240) of the second conductivity type (P-type) extend into a drift zone (#100 N-drift layer). (See Chang Fig.1, Fig.5-6, [col 3 line 29-col 6 line 48]
Regarding Claim 15.
Chang teaches The vertical field effect transistor structure according to claim 13, Chang further teaches wherein the body connecting regions (#240) of the second conductivity type (P-type) electrically contact the doped zones of the second conductivity type (P-type regions below the trenches), and wherein a breakdown current path runs through the body connecting regions of the second conductivity type and through the doped zones of the second conductivity type.(See Chang Fig.5-6, [col 6 line 20- 48])
Regarding Claim 17.
Chang teaches The vertical field effect transistor structure according to claim 13, Chang further teaches wherein a spreading zone (#242) of the first conductivity type (N-type) is provided between the first connection region (#100) and the channel zone (#106). (See Chang Fig.5-6, [col 6 line 20- 48])
Regarding Claim 19.
Chang teaches in Fig.2 and in related text A method of manufacturing a vertical field effect transistor, the method comprising the following steps:
providing a semiconductor body having a first connecting zone (#100) and a second connecting zone (#108) of a first conductivity type (N-type), and a channel zone (#106) of the first conductivity type or a second conductivity type (P-type) complementary to the first conductivity type arranged between the first and second connecting zones;
forming a plurality of trenches (#20 trench gate structure) extending into the semiconductor body, the trenches reaching from the second connecting zone (#108) through the channel zone, into the first connecting zone (#100) and forming fins of the channel zone and the second connecting zone;
forming a control electrode (Fig.1 #24) arranged in the trenches, the electrode being located adjacent to the channel zone (#106) and insulated (#22) from the semiconductor body;
forming a reverse current path connected between the first and second connecting zones (#100, #108) and parallel to the channel zone (#106), the reverse current path including at least one p-n junction and being configured to conduct when a threshold voltage between the first and second connecting zones is reached;
forming a respective doped zone (Fig.5a #130 or Fig 6 #240) of the second conductivity type in the first connecting zone (#100) below the trenches;
forming body connecting regions (#116/#114/#240) of the second conductivity type (P-type) in the fins, the body connecting regions electrically contacting the channel zone (#106) and the second connecting zone; and
wherein the body connecting regions (#116/#114/#240) of the second conductivity type (P-type) are formed such that they extend into a drift zone (#100 N-drift layer).
(See Chang Fig.1, Fig.5-6, [col 3 line 29-col 6 line 48])
Regarding Claim 22.
Chang teaches The method according to claim 19,
Chang further teaches wherein the body connecting regions (#240) of the second conductivity type (P-type) are formed such that they electrically contact the doped zones of the second conductivity type (P-type regions below the trenches), and wherein a breakdown current path runs through the body connecting regions of the second conductivity type and through the doped zones of the second conductivity type. (See Chang Fig.5-6, [col 6 line 20- 48])
Regarding Claim 24.
Chang teaches The method according to claim 19,
Chang further teaches wherein a spreading zone (#242) of the first conductivity type (N-type) is provided between the first connection region (#100) and the channel zone (#106). (See Chang Fig.5-6, [col 6 line 20- 48])
Claim Rejections - 35 USC § 103
In the event the determination of the status of the application as subject to AIA 35 U.S.C. 102 and 103 (or as subject to pre-AIA 35 U.S.C. 102 and 103) is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for the rejection will not be considered a new ground of rejection if the prior art relied upon, and the rationale supporting the rejection, would be the same under either status.
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 14 and 21 are rejected under 35 U.S.C. 103 as being unpatentable over Chang, and further in view of DE201 (DE-10224201-B4)
Regarding Claim 14.
Chang teaches The vertical field effect transistor structure according to claim 13,
Chang does not explicitly disclose wherein the reverse current path runs within the trenches, wherein each of the trenches has a respective electrode arranged therein which is electrically conductively connected to the second connecting zone and is electrically insulated from the control electrode, and which contacts the doped zone of the second conductivity type at a bottom of the trenches.
However, DE201 in Fig.4, 5 and I related text, wherein the reverse current path runs within the trenches, wherein each of the trenches has a respective electrode (Fig.1, #80) arranged therein which is electrically conductively connected to the second connecting zone (#90) and is electrically insulated from the control electrode (#40), and which contacts the doped zone of the second conductivity type (P-type) at a bottom of the trenches.
It would have been obvious to one of ordinary skill in the art at the effective filing date of the claimed invention to modify Chang with the teachings of DE201, as identified above, in order to provide an integrated reverse/breakdown conduction path and simplify top-side contacting path.
Regarding Claim 21.
Chang teaches The method according to claim 19,
Chang does not explicitly disclose the reverse current path runs in the trenches, wherein in the trenches, a respective electrode is arranged which is electrically conductively connected to the second connecting zone and which is electrically insulated from the control electrode, and which contacts the doped zone of the second conductivity type at a bottom of the trenches.
However, DE201 in Fig.4, 5 and in related text, the reverse current path runs in the trenches, wherein in the trenches, a respective electrode (Fig.1 #80) is arranged which is electrically conductively connected to the second connecting zone (#90) and which is electrically insulated from the control electrode (#40), and which contacts the doped zone of the second conductivity type (P-type) at a bottom of the trenches.
It would have been obvious to one of ordinary skill in the art at the effective filing date of the claimed invention to modify Chang with the teachings of DE201, as identified above, in order to provide an integrated reverse/breakdown conduction path and simplify top-side contacting path.
Claims 16, 18, 20 and 23 are rejected under 35 U.S.C. 103 as being unpatentable over Chang as applied to claim 13 above, and further in view of Kyogoky et. al. (US-10199466-B1, hereinafter Kyogoky)
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Regarding Claim 16.
Chang teaches The vertical field effect transistor structure according to claim 13, Chang does not explicitly disclose wherein the first connecting zone includes a lower doped drift region and a higher doped drain region of the first conductivity type, the doped zones of the second conductivity type being arranged in the drift region, and wherein the body connecting regions of the second conductivity type extend into the drift region.
However, Kyogoky teaches in Fig.1 wherein the first connecting zone (#24/#26) includes a lower doped drift region (#26) and a higher doped drain region (#24) of the first conductivity type (N-type), the doped zones (#32a/#32b) of the second conductivity type (P-type) being arranged in the drift region (#26), and wherein the body connecting regions of the second conductivity type extend into the drift region (#26).
It would have been obvious to one of ordinary skill in the art at the effective filing date of the claimed invention to modify Chang with the teachings of Kyogoky, as identified above, in order to obtain predictable tradeoffs of breakdown capability and on-resistance in a vertical power FET. This would have been a predictable substitution of a known doping architecture in the first connecting zone, yielding no more than expected results.
Regarding Claim 18.
Chang teaches The vertical field effect transistor structure according to claim 13, Chang does not explicitly disclose wherein the semiconductor body is made of silicon carbide (SiC) or gallium nitride (GaN).
Kyogoky teaches wherein the semiconductor body is made of silicon carbide (SiC) or gallium nitride (GaN). ([Col 5 line 12])
It would have been obvious to one of ordinary skill in the art at the effective filing date of the claimed invention to modify Chang with the teachings of Kyogoky, as identified above, as it is a recognized design choice to obtain predictable performance benefits without altering the fundamental architecture, making the substitution an obvious design alternatives.
Regarding Claim 20.
Chang teaches The method according to claim 19,
Chang does not explicitly disclose wherein the doped zones of the second conductivity type and the body connecting regions of the second conductivity type are formed in a common implantation step.
Kyogoky teaches wherein the doped zones of the second conductivity type and the body connecting regions of the second conductivity type are formed in a common implantation step. (See [col 11 line 54-62])
It would have been obvious to one of ordinary skill in the art at the effective filing date of the claimed invention to modify Chang with the teachings of Kyogoky, as identified above, as it is a routine process optimization that predictably reduces implant steps while producing the same implanted regions.
Regarding Claim 23.
Chang teaches The method according to claim 19,
Chang does not explicitly disclose wherein the first connecting zone includes a lower doped drift region and a higher doped drain region of the first conductivity type, the doped zones of the second conductivity type being arranged in the drift region, and wherein the body connecting regions of the second conductivity type extend into the drift region.
However, Kyogoky teaches in Fig.1 wherein the first connecting zone (#24/#26) includes a lower doped drift region (#26) and a higher doped drain region (#24) of the first conductivity type (N-type), the doped zones (#32a/#32b) of the second conductivity type (P-type) being arranged in the drift region (#26), and wherein the body connecting regions of the second conductivity type extend into the drift region (#26).
It would have been obvious to one of ordinary skill in the art at the effective filing date of the claimed invention to modify Chang with the teachings of Kyogoky, as identified above, in order to obtain predictable tradeoffs of breakdown capability and on-resistance in a vertical power FET. This would have been a predictable substitution of a known doping architecture in the first connecting zone, yielding no more than expected results.
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to SOPHIA W KAO whose telephone number is (703)756-4797. The examiner can normally be reached Monday-Friday 9am-5pm Pacific Time.
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/SOPHIA W KAO/Examiner, Art Unit 2817
/ELISEO RAMOS FELICIANO/Supervisory Patent Examiner, Art Unit 2817