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 .
DETAILED ACTION
Status of the Claims
Applicant’s remarks/amendments of claims 1-10 in the reply filed on March 24th, 2026, are acknowledged. Claims 11-20 have been withdrawn from consideration. New claims 21-22 have been amended. Claims 1-22 are pending.
Action on merits of claims 1-10 and 21-22 as 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.
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 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.
Claims 1-10 and 21 are rejected under 35 U.S.C. 103 as being unpatentable over Akiyama (US 2013/0193485, hereinafter Akiya 485) in view of Oh (US 2021/0336045, hereinafter as Oh ‘045) and further in view of Kato (US 2017/0317183, hereinafter as Kato ‘183) as evidence.
Regarding Claim 1, Akiya 485 teaches a GaN-based semiconductor device, comprising:
a substrate (Fig. 1, (101); [0048]);
a GaN channel layer (103; [0048]) disposed on the substrate;
a AlGaN layer (104; [0048]) disposed on the GaN channel layer;
a p-GaN gate layer (105; [0041]) disposed on the AlGaN layer;
a nitrogen-rich TiN (see para. [0053]) hard mask layer disposed on the p-GaN gate layer.
Thus, Akiya 485 is shown to teach all the features of the claim with the exception of explicitly the features: “a nitrogen-rich TiN hard mask layer disposed directly on the p-GaN gate layer; wherein the nitrogen-rich TiN hard mask layer has a nitrogen-to-titanium (N/Ti) ratio that is greater than 1.0; and a gate electrode layer disposed on the nitrogen-rich TiN hard mask layer”.
Oh ‘045 teaches a nitrogen-rich TiN (Fig. 2, (150); [0085]) hard mask layer disposed on the p-GaN gate layer (140; [0082]); wherein the nitrogen-rich TiN hard mask layer (150) has a nitrogen-to-titanium (N/Ti) ratio that is adjustable (see para. [0085]); and a gate electrode layer (160; [0086]) disposed on the nitrogen-rich TiN hard mask layer (150).
Thus, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify Akiya 485 by having a nitrogen-rich TiN hard mask layer disposed directly on the p-GaN gate layer; wherein the nitrogen-rich TiN hard mask layer has a nitrogen-to-titanium (N/Ti) ratio that is adjustable; and a gate electrode layer disposed on the nitrogen-rich TiN hard mask layer for the purpose of providing the high electron mobility transistors (see para. [0005]) as suggested by Oh ‘045.
Thus, Akiya 485 and Oh ‘045 are shown to teach all the features of the claim with the exception of explicitly the features: “the nitrogen-rich TiN hard mask layer has a nitrogen-to-titanium (N/Ti) ratio that is greater than 1.0”.
However, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have the nitrogen-rich TiN hard mask layer has a nitrogen-to-titanium (N/Ti) ratio that is greater than 1.0, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233. See para. [0242]) of Kato ‘183 (the ratio of N to Ti in the TiN film is set to greater than 1). The claim would have been obvious in the absence of a showing that the claimed range(s) achieve unexpected results relative to the prior art range. In re Woodruff, 16 USPQ2d 1935, 1937 (Fed. Cir. 1990). See also In re Huang, 40 USPQ2d 1685, 1688 (Fed. Cir. 1996) (claimed ranges of a result effective variable, which do not overlap the prior art ranges, are unpatentable unless they produce a new and unexpected result which is different in kind and not merely in degree from the results of the prior art). See also In re Boesch, 205 USPQ 215 (CCPA) (discovery of optimum value of result effective variable in known process is ordinarily within skill of art) and In re Aller, 105 USPQ 233 (CCPA 1955) (selection of optimum ranges within prior art general conditions is obvious). A person of ordinary skills in the art is motivated to have the nitrogen-rich TiN hard mask layer has a nitrogen-to-titanium (N/Ti) ratio that is greater than 1.0 when this improves the performance of the semiconductor device.
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Fig. 2A (Akiya 485)
Regarding Claim 2, Akiya 485 teaches a buffer layer (Fig. 1, (102); [0048]) on the substrate (101), wherein the buffer layer (102) is disposed between the substrate (101) and the GaN channel layer (103).
Regarding Claim 3, Akiya 485 teaches the buffer layer (102; [0048]) comprises AlN or GaN, has a thickness of about 100 nm-2 µm.
Thus, Akiya 485 and Oh ‘045 are shown to teach all the features of the claim with the exception of explicitly the limitations: “a thickness of about 3-5 µm”.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have the buffer thickness of about 3-5 µm, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233. The claim would have been obvious in the absence of a showing that the claimed range(s) achieve unexpected results relative to the prior art range. In re Woodruff, 16 USPQ2d 1935, 1937 (Fed. Cir. 1990). See also In re Huang, 40 USPQ2d 1685, 1688 (Fed. Cir. 1996) (claimed ranges of a result effective variable, which do not overlap the prior art ranges, are unpatentable unless they produce a new and unexpected result which is different in kind and not merely in degree from the results of the prior art). See also In re Boesch, 205 USPQ 215 (CCPA) (discovery of optimum value of result effective variable in known process is ordinarily within skill of art) and In re Aller, 105 USPQ 233 (CCPA 1955) (selection of optimum ranges within prior art general conditions is obvious). A person of ordinary skills in the art is motivated to have the buffer thickness of about 3-5 µm when this improves the performance of the semiconductor device.
Regarding Claim 4, Akiya 485 teaches the GaN channel layer (103; [0048]) has a thickness of 1-3 µm.
Thus, Akiya 485 and Oh ‘045 are shown to teach all the features of the claim with the exception of explicitly the limitations: “a thickness of 200-400 nm”.
It would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have the thickness of about 200-400 nm, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233. The claim would have been obvious in the absence of a showing that the claimed range(s) achieve unexpected results relative to the prior art range. In re Woodruff, 16 USPQ2d 1935, 1937 (Fed. Cir. 1990). See also In re Huang, 40 USPQ2d 1685, 1688 (Fed. Cir. 1996) (claimed ranges of a result effective variable, which do not overlap the prior art ranges, are unpatentable unless they produce a new and unexpected result which is different in kind and not merely in degree from the results of the prior art). See also In re Boesch, 205 USPQ 215 (CCPA) (discovery of optimum value of result effective variable in known process is ordinarily within skill of art) and In re Aller, 105 USPQ 233 (CCPA 1955) (selection of optimum ranges within prior art general conditions is obvious). A person of ordinary skills in the art is motivated to have the thickness of about 200-400 nm when this improves the performance of the semiconductor device.
Regarding Claim 5, Akiya 485 teaches the AlGaN layer (104; [0048]) has a thickness of 5-40 nm which overlaps the claim range thickness of 10-14 nm.
Regarding Claim 6, Akiya 485 teaches the p-GaN gate layer (105; [0048]) has a thickness of 10-300 nm which overlaps the claim range thickness of 60-100 nm.
Regarding Claim 7, Oh ‘045 teaches the gate electrode layer (160; [0088]) comprises (TiN) is in direct contact with the nitrogen-rich TiN hard mask layer (150; [0085]).
Thus, Akiya 485 and Oh ‘045 are shown to teach all the features of the claim with the exception of explicitly the limitations: “the gate electrode layer comprises a TiN bottom layer, a AlCu middle layer, and a TiN top layer, wherein the TiN bottom layer is in direct contact with the nitrogen-rich TiN hard mask layer”.
However, it has been held to be within the general skill of a worker in the art to select a known material for the gate electrode (e.g. a TiN bottom layer, a AlCu middle layer, and a TiN top layer) on the basis of it suitability for the intended use as a matter of obvious design choice. In re Leshin, 125 USPQ 416. See para. [0040] of Chang (US 2018/0337093) as evidence). A person of ordinary skills in the art is motivated to have the gate electrode layer comprises a TiN bottom layer, a AlCu middle layer, and a TiN top layer when this improves the performance of the semiconductor device.
Regarding Claim 8, Oh ‘045 teaches the N/Ti ratio of the TiN hard mask layer is adjustable (see para. [0085]).
Thus, Akiya 485 and Oh ‘045 are shown to teach all the features of the claim with the exception of explicitly the features: “the N/Ti ratio of the TiN hard mask layer is greater than 1.04”.
However, it would have been obvious to one having ordinary skill in the art before the effective filing date of the claimed invention to have the N/Ti ratio of the TiN hard mask layer is greater than 1.04, since it has been held that where the general conditions of a claim are disclosed in the prior art, discovering the optimum or workable ranges involves only routine skill in the art. In re Aller, 105 USPQ 233. See para. [0242]) of Kato ‘183 (the ratio of N to Ti in the TiN film is set to greater than 1). The claim would have been obvious in the absence of a showing that the claimed range(s) achieve unexpected results relative to the prior art range. In re Woodruff, 16 USPQ2d 1935, 1937 (Fed. Cir. 1990). See also In re Huang, 40 USPQ2d 1685, 1688 (Fed. Cir. 1996) (claimed ranges of a result effective variable, which do not overlap the prior art ranges, are unpatentable unless they produce a new and unexpected result which is different in kind and not merely in degree from the results of the prior art). See also In re Boesch, 205 USPQ 215 (CCPA) (discovery of optimum value of result effective variable in known process is ordinarily within skill of art) and In re Aller, 105 USPQ 233 (CCPA 1955) (selection of optimum ranges within prior art general conditions is obvious). A person of ordinary skills in the art is motivated to have the N/Ti ratio of the TiN hard mask layer is greater than 1.04 when this improves the performance of the semiconductor device.
Regarding Claim 9, Akiya 485 teaches a A1203 passivation layer (Fig. 15, (132); [0080]) covering a sidewall of the nitrogen-rich TiN hard mask layer (108), and a top surface of the AlGaN layer (104) and the protective layer (107) covering a sidewall of the p-GaN gate layer (105).
Thus, Akiya 485 and Oh ‘045 are shown to teach all the features of the claim with the exception of explicitly the limitations: “a A1203 passivation layer covering a sidewall of the p-GaN gate layer”.
However, it has been held to be within the general skill of a worker in the art to select a A1203 passivation layer covering a sidewall of the p-GaN gate layer on the basis of it suitability for the intended use as a matter of obvious design choice. In re Leshin, 125 USPQ 416. A person of ordinary skills in the art is motivated to have a A1203 passivation layer covering a sidewall of the p-GaN gate layer when this improves the performance of the semiconductor device.
Regarding Claim 10, Akiya 485 teaches an insulating layer (a silicon oxide film, Fig. 15, (109); [0055]) disposed on the A1203 passivation layer (132; [0080]).
Regarding Claim 21, Oh ‘045 teaches a sidewall of the nitrogen-rich TiN hard mask layer (150) is flush with a sidewall of the p-GaN gate layer (140; [0082]) (see Fig. 2).
Claim 22 is rejected under 35 U.S.C. 103 as being unpatentable over Akiya 485 and Oh ‘045 as applied to claim 9 above, and further in view of Lin (US 2022/0336649, hereinafter as Lin ‘649).
Regarding Claim 22, Akiya 485 and Oh ‘045 are shown to teach all the features of the claim with the exception of explicitly the limitations: “the A1203 passivation layer is in direct contact with the sidewall of the p-GaN gate layer”.
Lin ‘649 teaches the A1203 passivation layer (Fig. 4, (160); [0040]) is in direct contact with the sidewall of the p-GaN gate layer (110; [0032]).
Thus, it would have been obvious to a person of ordinary skill in the art before the effective filing date of the invention to modify Akiya 485 and Oh ‘045 by having the A1203 passivation layer is in direct contact with the sidewall of the p-GaN gate layer for the purpose of providing an improved high electron mobility transistor (see para. [0004]) as suggested by Lin ‘649.
Response to Arguments
Applicant’s arguments with respect to claims 1-10 and 21-22, filed on March 24th, 2026, have been considered but are moot in view of the new ground of rejection.
Interviews After Final
Applicants note that an interview after a final rejection is permitted in order to place the application in condition for allowance or to resolve issues prior to appeal. However, prior to the interview, the intended purpose and content of the interview should be presented briefly, preferably in writing. Upon review of the agenda, the Examiner may grant the interview if the examiner is convinced that disposal or clarification for appeal may be accomplished with only nominal further consideration. Interviews merely to restate arguments of record or to discuss new limitations will be denied. See MPEP § 714.13
Conclusion
Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicant is reminded of the extension of time policy as set forth in 37 CFR 1.136(a).
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.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Examiner Dzung Tran whose telephone number is (571) 270-3911. The examiner can normally be reached on M-F 8 AM-5PM.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Supervisor Sue Purvis can be reached on 571-272-1236. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/DZUNG TRAN/
Primary Examiner, Art Unit 2893
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