DETAILED ACTION
This Office action responds to the Applicant’s amendments and arguments filed on 05/15/2026.
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 . In the event the determination of the status of the application as subject to AIA 35 is incorrect, any correction of the statutory basis (i.e., changing from AIA to pre-AIA ) for a 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.
Amendment Status
The present Office action is made with all previously suggested amendments being fully considered. Accordingly, pending in this Office action are claims 1-2, 7-8, and 10-15. Claims 3-6, and 9 were cancelled by the Applicant.
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 gate field plate recited in claims 1 must be shown the drawings or the feature(s) canceled from the claim(s). The gate field plate 158 from specification is not shown in the drawings.
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 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.
Claims 1-2, and 10-15 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Zhao (US 2022/0376061).
Regarding claim 1, Zhao shows (see, e.g., Zhao: figs. 1A-1C) all aspects of the instant invention including a semiconductor device structure for lateral power transistor 100A (see, e.g., Zhao: par. [0002]), comprising a drain contact structure including:
A drain ohmic contact 126
A drain terminal structure including a first drain field plate and a second drain field plate
The first drain field plate being formed in a first metallization layer which is a same metallization layer in which the gate field plate is formed such that the gate field plate and the first drain field plate are formed of the same material (see, e.g., Zhao: annotated fig. 1B)
The second drain field plate being formed in a second metallization layer different from the first metallization layer (see, e.g., Zhao: annotated fig. 1B)
The first drain field plate extending laterally over an edge of the drain ohmic contact 126 over a channel region in a direction toward a source region (see, e.g., Zhao: fig. 1C)
The second drain field plate extending laterally over an edge of the drain ohmic contact 126 over a channel region in a direction toward a source region (see, e.g., Zhao: fig. 1C)
The first drain field plate and the second drain field plate having different capacitive coupling to the channel region (see, e.g., Zhao: fig. 1C)
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Regarding claim 2, Zhao shows (see, e.g., Zhao: figs. 1A-1C) shows that the lateral power transistor comprises a GaN HEMT (see, e.g., Zhao: par. [0021] and [0001]).
Regarding claim 10, Zhao shows (see, e.g., Zhao: figs. 1B-1C) that the first metallization layer 134 is a layer of titanium nitride (see, e.g., Zhao: par. [0051]) such that the gate field plate and the first drain plate are titanium nitride.
Regarding claim 11, Zhao shows (see, e.g., Zhao: figs. 1A-1C) that the lateral GaN semiconductor power transistor (see, e.g., Zhao: par. [0002]) is an enhancement-mode GaN HEMT (see, e.g., Zhao: par. [0025] and [0028]).
Regarding claim 12, Zhao shows (see, e.g., Zhao: figs. 1A-1C) that the second drain field plate is formed in an interconnect metallization layer that defines a drain metal contact.
Regarding claim 13, Zhao shows (see, e.g., Zhao: figs. 1A-1C) that the second drain field plate is vertically spaced from the first drain field plate by an intermetal dielectric layer 138.
Regarding claim 14, Zhao shows (see, e.g., Zhao: figs. 1A-1C) that the intermetal dielectric layer 138 is disposed between the first drain field plate and the second drain field plate.
Regarding claim 15, Zhao shows (see, e.g., Zhao: figs. 1A-1C) that the first metallization layer comprises a conductive layer that also defines the gate field plate extending from a gate region toward the drain contact.
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 7 and 8 are rejected under 35 U.S.C. 103 as being unpatentable over Zhao in view of Wong (US 2022/0123109).
Regarding claim 7, Zhao shows (see, e.g., Zhao: figs. 1A-1C) a first drain field plate that extends laterally from the edge of the drain ohmic contact.
However, Zhao fails (see, e.g., Zhao: figs. 1A-1C) to show that the first drain field plate that extends laterally from the edge of the drain ohmic contact by a distance of at least 1 µm. Wong, in a similar device to Zhao, discloses (see, e.g., Wong: fig. 3) a drain terminal structure 72 with the first field plate 110 extending laterally beyond the drain ohmic contact 80 by a first distance W2 in the source direction 71 (see, e.g., Wong: par. [0058]). Wong shows (see, e.g., Wong: fig. 3) that the first distance W2 is at least 1µm (see, e.g., Wong: par. [0058]) such as an electric field near the drain 72 can be further reduced, and the reliability degree of the semiconductor device 1c can be improved (see, e.g., Wong: par. [0058] and [0068]).
It would have been obvious at the time of filing the invention to one of ordinary skill in the art to have the first field plate that extends laterally from the edge of the drain ohmic contact by a distance of at least 1 µm as suggested by Wong in the semiconductor device of Zhao to reduce an electric field near the drain, and improve the reliability degree of the semiconductor device.
However, the differences in the distance will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such differences are critical. “Where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the workable ranges by routine experimentation”. In re Aller, 220 F.2d 454,456,105 USPQ 233, 235 (CCPA 1955).
Accordingly, since the applicant has not established the criticality (see next paragraph below) of the mentioned distances, and Wong has identified such distances as result-effective variables subject to optimization (see, e.g., Wong: par. [0058] and [0068]), it would have been obvious to one of ordinary skill in the art to use these temperature values in the method of Zhao in view of Wong.
CRITICALITY
The specification contains no disclosure of either the critical nature of the claimed distance values or any unexpected results arising therefrom. Where patentability is said to be based upon particular chosen dimensions or upon another variable recited in a claim, the applicant must show that the chosen dimensions are critical. In re Woodruff, 919 F.2d 1575, 1578, 16 USPQ2d 1934, 1936 (Fed. Cir. 1990).
Regarding claim 8, Zhao shows (see, e.g., Zhao: figs. 1A-1C) a second drain field plate that extends laterally from the edge of the drain ohmic contact.
However, Zhao fails (see, e.g., Zhao: figs. 1A-1C) to show that the first drain field plate that extends laterally from the edge of the drain ohmic contact by a distance of at least 1 µm. Wong, in a similar device to Zhao, discloses (see, e.g., Wong: fig. 3) a drain terminal structure 72 with the second field plate 100 extending laterally beyond the first field plate 110 by a second distance W1 in the source direction 71 (see, e.g., Wong: par. [0058]). Wong shows (see, e.g., Wong: fig. 3) that the first distance W2 is at least 1µm (see, e.g., Wong: par. [0058]) such as an electric field near the drain 72 can be further reduced, and the reliability degree of the semiconductor device 1c can be improved (see, e.g., Wong: par. [0058] and [0068]).
It would have been obvious at the time of filing the invention to one of ordinary skill in the art to have the second field plate that extends laterally from the edge of the drain ohmic contact by a distance of at least 1 µm as suggested by Wong in the semiconductor device of Zhao to reduce an electric field near the drain, and improve the reliability degree of the semiconductor device.
However, the differences in the distance will not support the patentability of subject matter encompassed by the prior art unless there is evidence indicating such differences are critical. “Where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the workable ranges by routine experimentation”. In re Aller, 220 F.2d 454,456,105 USPQ 233, 235 (CCPA 1955).
Accordingly, since the applicant has not established the criticality (see paragraph 23) of the mentioned distances, and Wong has identified such distances as result-effective variables subject to optimization (see, e.g., Wong: par. [0058] and [0068]), it would have been obvious to one of ordinary skill in the art to use these temperature values in the method of Zhao in view of Wong.
Response to Arguments
Examiner has read and considered Applicants’ arguments, and finds them to be unpersuasive. Applicant’s arguments involve discussing why the previously cited prior art documents fail to disclose the amended limitation. Examiner believes that the Zhao disclose the amended limitation. The applicability of the Zhao and Wong references to the amended limitation is indicated in the claim rejections above.
The applicants argue:
The teaching of Zhao fails to anticipate or otherwise render obvious that "… the first drain field plate being formed in a first metallization layer which is a same metallization layer in which the gate field plate is formed such that the gate field plate and the first drain field plate are formed of the same material,”, as recited in Claim 1.
The examiner responds:
In view of the new grounds of rejection of Zhao, where Zhao clearly shows, see, e.g., Zhao: annotated fig. 1B, that the first drain field plate being formed in a first metallization layer which is a same metallization layer in which the gate field plate is formed such that the gate field plate and the first drain field plate are formed of the same material.
Conclusion
A shortened statutory period for reply to this final action is set to expire three months from the mailing date of this action. In the event a first reply is filed within two months of the mailing date of this final action and the advisory action is not mailed until after the end of the three-month shortened statutory period, then the shortened statutory period will expire on the date the advisory action is mailed, and any extension fee pursuant to 37 CFR 1.136(a) will be calculated from the mailing date of the advisory action. In no event, however, will the statutory period for reply expire later than six months from the date of this final action.
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/TIBERIU DAN ONUTA/Examiner, Art Unit 2814
/WAEL M FAHMY/Supervisory Patent Examiner, Art Unit 2814
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