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 without traverse of Group II, claims 11-20, in the reply filed on 1/30/26 is acknowledged.
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 11-20 are rejected under 35 U.S.C. 103 as being unpatentable over Hwang et al. (US 2022/0367698) in view of Chen et al. (US 2007/0228416).
Regarding claim 11, Hwang discloses an integrated circuit platform comprising:
a first HEMT and a second HEMT (11, 12, fig. 1);
wherein the first HEMT is comprised of a p-doped GaN gate (41, fig. 1 and paragraph 0059) on an AlGaN layer (30, fig. 1 and paragraph 0059); and wherein the second HEMT is comprised of a depleted p-GaN gate deactivated with an in-situ plasma treatment on the AlGaN layer (42, figs. 1, 9 and paragraphs 0068 and 0089-0096). Hwang further discloses that such processes produce HEMTs 11 and 12 with different threshold voltages. Hwang does not explicitly disclose wherein the first HEMT is a normally-off HEMT and the second HEMT is a normally-on HEMT. However, it would have been obvious to one of ordinary skill in the art at the time of filing to utilize Hwang’s teachings to form both a normally-off (enhancement-mode) HEMT and a normally-on (depletion-mode) HEMT, defined by having different threshold voltages since such was commonly known and practiced in the art at the time of filing for the purpose of optimizing the electrical characteristics of both HEMTs. To illustrate such known teachings see Chen (Abstract, paragraphs 0001-0019).
Regarding claim 12, Hwang further discloses wherein the normally-off HEMT further comprises a plurality of alumina layers (81, 82, fig. 1 and paragraphs 0066-0069); and wherein the normally-on HEMT further comprises a single alumina layer (82, fig. 1 and paragraphs 0066-0069).
Regarding claim 13, Hwang further discloses comprising a first silicon based
dielectric layer (paragraph 0080). Hwang does not disclose wherein the first silicon based dielectric layer has a thickness of 70nm. However, such dimensions would be considered obvious to one of ordinary skill in the art at the time of filing and the Examiner takes official notice of such.
Regarding claim 14, Hwang further discloses wherein the depleted p-GaN gate comprises Mg-H formed from diffusing hydrogen into the depleted p-GaN gate (paragraphs 0068, 0070, 0089-0096).
Regarding claim 15, Hwang further discloses a first portion of the AlGaN layer, wherein the first portion of the AlGaN layer comprises deactivated magnesium from exposure to the in-situ plasma treatment (paragraphs 0089-0096).
Regarding claim 16, Hwang further discloses wherein the normally-off HEMT further comprises metallization layers associated with a normally-off HEMT gate (51, fig. 1), a normally-off HEMT source (61, fig. 1), and a normally-off HEMT drain(71, fig. 1); and wherein the normally-on HEMT further comprises metallization layers associated with a normally-on HEMT gate (52, fig. 1), a normally-on HEMT source (62, fig. 1), and a normally-on HEMT drain (72, fig. 1).
Regarding claim 17, Hwang in view of Chen discloses the integrated circuit platform of claim 16, as mentioned above. Hwang does not explicitly disclose wherein the normally-off HEMT further comprises at least a first metal shielding layer; and
wherein the normally-on HEMT further comprises at least a second metal shielding layer. However, the use of shielding with AlGaN/GaN based HEMTs was widely practiced in the art since such HEMTs were commonly used for rf/microwave power amplifiers and would therefore be deemed obvious to one of ordinary skill in the art at the time of filing.
Regarding claims 18 and 19, Hwang in view of Chen discloses the integrated circuit platform of claim 11, as mentioned above. Hwang in view of Chen does not explicitly disclose wherein the depleted p-GaN gate of the normally-on HEMT has a flat capacitance trend as voltage increases or wherein the p-doped GaN gate of the
normally-off HEMT has a Schottky capacitance trend as voltage increases. However, such capacitance characteristics for HEMTs was well established at the time of filing and would therefore be deemed obvious to one of ordinary skill in the art at the time of filing.
Regarding claim 20, Hwang discloses that the p-doped GaN gate and the depleted p-GaN gate are covered by a conductive metal or metal compound or the like (paragraph 0091). Hwang does not explicitly disclose TiN, however, such material is commonly employed in the art and would therefore be deemed obvious to one of ordinary skill in the art at the time of filing.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure. US Patent Application Publication 20120319758 discloses relevant HEMT devices utilizing both E-mode and D-mode HEMTs.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to DOUGLAS M MENZ whose telephone number is (571)272-1877. The examiner can normally be reached Monday-Friday 8:00am-5:00pm.
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/DOUGLAS M MENZ/Primary Examiner, Art Unit 2897 3/7/26