DETAILED ACTION
This Office Action is in response to Amendment filed February 2, 2026.
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
Claim 6 is withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected species, because (a) Applicants elected subspecies a drawn to the embodiment shown in Fig. 10(b) of current application in the Election filed September 23, 2025, and (b) the amended claim 6 reciting “a curved increase” is directed to a nonelected species drawn to the embodiment shown in Fig. 10(d) or 10(e) of current application.
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 configuration corresponding to the limitation “a hydrogen concentration of the high-resistance passivation region has a maximum at an upper surface of the P-type semiconductor layer on a side away from the substrate” recited on lines 7-8 of claim 1, and the configuration corresponding to the limitation “the hydrogen concentration of the high-resistance region monotonically increases along the first direction” recited on lines 1-3 of claim 5 must be shown or the features canceled from the claims, because (a) an actual concentration profile of hydrogen atoms would depend on numerous parameters such as how the hydrogen atoms are introduced, whether annealing is performed and whether hydrogen atoms diffuse into neighboring layers, (b) as discussed below under 35 USC 112(b) rejections, the limitation cited above appears to be directed to Applicants’ intention or design rather than being directed to an actual feature that Applicants experimentally measured from the claimed semiconductor structure, (c) for example, as Fig. 9 of Tang et al. (“Investigation of the passivation-induced VTH shift in p-GaN HEMTs with Au-free gate-first process,” Microelectronics Reliability 122 (2021) 114150) shows, depending on the passivation layer material, and whether the passivation layer material contains hydrogen atoms, the hydrogen concentration profile may not exhibit a monotonous increase at the top of the P-type semiconductor layer as Applicants intended, see the circled area illustrated below, and (d) therefore, Applicants did not show an actual hydrogen concentration profile that reads on the newly added limitations of claims 1 and 5 cited above.
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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 Objections
Claim 5 is objected to because of the following informalities: “along the first direction” should be replaced with “in the first direction” on line 3 to be consistent with the phrase “in a first direction” recited on line 3 of claim 1. Appropriate correction is required.
Claim Rejections - 35 USC § 112
The following is a quotation of 35 U.S.C. 112(b):
(b) CONCLUSION.—The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the inventor or a joint inventor regards as the invention.
The following is a quotation of 35 U.S.C. 112 (pre-AIA ), second paragraph:
The specification shall conclude with one or more claims particularly pointing out and distinctly claiming the subject matter which the applicant regards as his invention.
Claims 1-5, 10-12, 14 and 20 are rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
(1) Regarding claim 1, it is not clear whether the claimed invention is directed to an actual feature or directed to an inventive concept or a design, because (a) the newly added limitation “a hydrogen concentration of the high-resistance passivation region has a maximum at an upper surface of the P-type semiconductor layer on a side away from the substrate” recited on lines 7-8 appears to be based on the illustration of Fig. 10(b) of current application, (b) however, in reality, the P-type semiconductor layer, which is the composite layer of the activation region 42 and the high-resistance passivation region 41, would have a top portion that would form an interface with the gate 53, where the atoms constituting the P-type semiconductor layer 41/42 would diffuse toward and into the gate 53, and the atoms constituting the gate 53 would diffuse toward and into the P-type semiconductor layer 41/42, (c) therefore, it is more likely that the hydrogen concentration would decrease at the topmost region of the P-type semiconductor layer 41/42 since hydrogen atoms in this region would diffuse into the gate 53, see the illustration below with the arrow in Fig. 10(b) indicating decrease of a hydrogen concentration due to diffusion of hydrogen atoms from the P-type semiconductor layer 41/42 into the gate 53, while hydrogen atoms in the remainder of the P-type semiconductor layer 41/42 would not, and (d) in this case, it appears that the newly added limitation “a hydrogen concentration of the high-resistance passivation region has a maximum at an upper surface of the P-type semiconductor layer on a side away from the substrate” recited on lines 7-8 is directed to the illustration of Fig. 10(b) of current application rather than an actual hydrogen distribution/profile in the P-type semiconductor layer, especially when it appears that Applicants did not measure the hydrogen distribution/profile in an actual P-type semiconductor layer after the claimed semiconductor structure is formed. Claims 2-5, 10-12, 14 and 20 depend on claim 1, and therefore, claims 2-5, 10-12, 14 and 20 are also indefinite.
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(2) Regarding claims 2, it is not clear what “the hydrogen concentration of the high-resistance passivation region” recited on lines 1-2 refers to, because (a) because the amended claim 1 recites a hydrogen concentration of the high-resistance passivation region that is not constant, and (b) therefore, technically Applicants did not claim where “the hydrogen concentration of the high-resistance passivation region” is measured in claim 1, and thus the limitation “the hydrogen concentration of the high-resistance passivation region” recited on lines 1-2 lacks the antecedent basis since “the hydrogen concentration of the high-resistance passivation region” does not necessarily imply the maximum hydrogen concentration recited in the amended claim 1.
(3) Further regarding claim 2, it is not clear what “a hydrogen concentration of the activation region” recited on lines 2-3, because (a) Applicants amended claim 1 to claim that “a hydrogen concentration of the high-resistance passivation region has a maximum at an upper surface of the P-type semiconductor layer on a side away from the substrate” recited on lines 7-8 of claim 1, and (b) therefore, it appears that the activation region should also have a varying concentration profile, in which case it is not clear whether “the hydrogen concentration of the high-resistance passivation region”, which is already indefinite as discussed above, “is higher than” any “hydrogen concentration of the activation region”, or one or more “hydrogen concentration of the activation region”, depending on which interpretation one needs to adopt, the claimed semiconductor structure would have distinct profiles of hydrogen atoms in the activation region.
Claims 3-5, 10-12, 14 and 20 depend on claim 2, and therefore, claims 3-5, 10-12, 14 and 20 are also indefinite.
(4) Regarding claim 5, it is not clear whether the limitation “the hydrogen concentration of the high-resistance region monotonically increases along the first direction” recited on lines 1-3 is directed to an actually measured hydrogen concentration profile, or a hydrogen concentration profile that Applicants intended to achieve but may not have obtained, because as discussed above under Drawings objection and 35 USC 112(b) rejections, an actual hydrogen concentration profile would not exactly resemble the hydrogen concentration profile shown in Fig. 10(b) of current application showing a monotonic increase of the hydrogen concentration.
(5) Regarding claims 5 and 20, it is not clear how the monotonic increase recited in claim 5 can comprise “a stepped increase” as recited in claim 20, because (a) a stepped increase is not a monotonic increase since there should be at least one plateau for “a stepped increase”, and (b) therefore, it is not clear whether the monotonic increase recited in claim 5 is not exactly a monotonic increase, or the stepped increase recited in claim 20 is not exactly a monotonic increase.
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 1-3, 5, 10-12, 14 and 20, as best understood, are rejected under 35 U.S.C. 102(a)(1) as being anticipated by Tang et al. (“Investigation of the passivation-induced VTH shift in p-GaN HEMTs with Au-free gate-first process,” Microelectronics Reliability 122 (2021) 114150)
Regarding claim 1, Tang et al. disclose a semiconductor structure (Figs. 1(c), 7 and 9 with SiO2 passivation), comprising: a substrate (Si(111)), a channel layer (GaN), a barrier layer (AlGaN) and a P-type semiconductor layer (p-GaN) sequentially stacked in a first direction (vertical direction in Figs. 1(c) and 7); wherein the P-type semiconductor layer comprises a high-resistance passivation region (top portion of p-GaN indicated by rectangle illustrated below) and an activation region (bottom portion of p-GaN), because (a) the word “region” does not necessarily suggest any specific region, and (b) the top and bottom portion of the p-GaN layer of Tang et al. has distinct hydrogen concentration profiles, and the high-resistance passivation region is located on a side, away from the substrate, of the activation region, wherein a hydrogen concentration of the high-resistance passivation region (top rectangular portion of p-GaN illustrated below) has a maximum at an upper surface of the P-type semiconductor layer on a side away from the substrate (Si(111)).
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Regarding claims 2, 3, 5, 10-12, 14 and 20, Tang et al. further disclose that the hydrogen concentration of the high-resistance passivation region (arbitrarily selected hydrogen concentration in rectangular area illustrated above) is higher than a hydrogen concentration of the activation region (arbitrarily selected hydrogen concentration in bottom portion of p-GaN) (claim 2), wherein the hydrogen concentration of the high-resistance passivation region (arbitrarily selected hydrogen concentration in rectangular area illustrated above) is less than or equal to a magnesium concentration of the activation region (arbitrary selected magnesium concentration in bottom portion of p-GaN) (claim 3), the hydrogen concentration of the high-resistance passivation region (arbitrarily selected hydrogen concentration in rectangular area illustrated above) monotonically increases along the first direction (vertical direction in Figs. 1(c) and 7) from an interface between the activation region (bottom portion of p-GaN) and the high-resistance passivation region (rectangular area illustrated above) toward the upper surface of the P-type semiconductor layer (p-GaN) (claim 5), a thickness of the P-type semiconductor layer (p-GaN) in the first direction is 20 to 150 nm (80 nm in first paragraph under 2. Device structure and fabrication) (claim 10), wherein a thickness of the high-resistance passivation region (rectangular area illustrated above) in the first direction (vertical direction in Figs. 1(c) and 7) is 1 to 50 nm, because (a) the thickness of the P-type semiconductor layer is 80 nm as disclosed by Tang et al., and (b) the rectangular area illustrated above is about or slightly less than one half of the P-type semiconductor layer (claim 11), a projected area of the high-resistance passivation region (rectangular area illustrated above) on the substrate (Si(111)) is equal to a projected area of the activation region on the substrate (bottom portion of p-GaN) (claim 12), further comprising: a gate (TiN in Fig. 1(c)), located on a side, away from the substrate (Si(111)), of the P-type semiconductor layer (p-GaN), and a source (one of Ohmic Contacts) and a drain (the other of Ohmic Contacts), located on a side, away from the substrate, of the channel layer (GaN) wherein the source and the drain are located on both sides of the gate (claim 14), and an increasing trend of the hydrogen concentration of the high-resistance passivation region (rectangular region illustrated above) in the first direction (vertical direction in Figs. 1(c) and 7) comprises a linear increase or a stepped increase (claim 20).
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 4, as best understood, is rejected under 35 U.S.C. 103 as being unpatentable over Tang et al. (“Investigation of the passivation-induced VTH shift in p-GaN HEMTs with Au-free gate-first process,” Microelectronics Reliability 122 (2021) 114150) The teachings of Tang et al. are discussed above.
Regarding claim 4, Tang et al. differ from the claimed invention by not showing that the hydrogen concentration of the high-resistance passivation region is 1E18/cm³ to 1E20/cm³.
It would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that the hydrogen concentration of the high-resistance passivation region can be 1E18/cm³ to 1E20/cm³, because the hydrogen concentration of the high-resistance passivation region should be controlled and optimized to obtain desired insulating characteristics of the high-resistance passivation region, which would determine the device characteristics such as a threshold voltage.
Response to Arguments
Applicants’ arguments with respect to claim 1 have been considered but are moot because the new ground of rejection does not rely on any reference applied in the prior rejection of record for any teaching or matter specifically challenged in the argument.
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure.
Tomabechi (US 2013/0075788)
Minoura (US 2013/0075750)
Wang et al., “Investigation of Thermally Induced Threshold Voltage Shift in Normally-OFF p-GaN Gate HEMTs,” IEEE TRANSACTIONS ON ELECTRON DEVICES 69 (2022) pp. 2287-2292.
Chiu et al., “Low-Mg out-diffusion of a normally off p-GaN gate high-electron-mobility transistor by using the laser activation technique,” Materials Science in Semiconductor Processing 117 (2020) 105166.
Liu et al., “The influence of lightly doped p-GaN cap layer on p-GaN/AlGaN/GaN HEMT,” Semiconductor Science & Technology 37 (2022) 075005.
Hao et al., “Studies on Fabrication and Reliability of GaN High-Resistivity-Cap-Layer HEMT,” IEEE TRANSACTIONS ON ELECTRON DEVICES 65 (2018) pp. 1314-1420.
Liu et al., “Suppression of the regrowth interface leakage current in AlGaN/GaN HEMTs by unactivated Mg doped GaN layer,” Applied Physics Letters 118 (2021) 072103.
Song et al., “Interface Si donor control to improve dynamic performance of AlGaN/GaN MIS-HEMTs,” AIP ADVANCES 7 (2017) 125023.
Czernecki et al., “Hydrogen diffusion in GaN:Mg and GaN:Si,” Journal of Alloys and Compounds 747 (2018) pp. 354-358.
Yang et al., “Influence of hydrogen impurities on p-type resistivity in Mg-doped GaN films,” Journal of Vacuum Science & Technology A 33 (2015) 021505.
Dai et al., “High Hole Concentration and Diffusion Suppression of Heavily Mg-Doped p-GaN for Application in Enhanced-Mode GaN HEMT,” Nanomaterials 11 (2021) 1766.
Arakawa et al., “High hole mobility p-type GaN with low residual hydrogen concentration prepared by pulsed sputtering,” APLMATERIALS 4 (2016) 086103.
Applicants' amendment necessitated the new grounds of rejection presented in this Office action. Accordingly, THIS ACTION IS MADE FINAL. See MPEP § 706.07(a). Applicants are 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 nonprovisional extension fee (37 CFR 1.17(a)) 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 mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to JAY C KIM whose telephone number is (571) 270-1620. The examiner can normally be reached 8:00 AM - 6:00 PM EST.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Joshua Benitez can be reached at (571) 270-1435. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/JAY C KIM/Primary Examiner, Art Unit 2815
/J.K./Primary Examiner, Art Unit 2815 March 30, 2026
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