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 .
Response to Arguments
Applicant's arguments filed 06/10/2026 have been fully considered but they are either not persuasive or moot in view of the updated grounds of rejection as necessitated by Applicant’s claim amendments or indication of allowable subject matter as detailed below.
Applicant argues on page 9 that the Moens reference does not teach the amended language of the first drain contact extends to a first depth within the gallium nitride layer, the first source contact extends to a second depth within the gallium nitride layer, with specifically the second depth being different than the first depth. The examiner agrees in that the maximum depth the source contact and the drain contacts are at the same maximum depth. However, the claims do not specifically require the depth be interpreted as the maximum depth. Applicant has not expressly defined the term “depth” and it has been held that claims are to be interpreted during examination under the doctrine of broadest reasonable interpretation (BRI, MPEP 2111) wherein in the instant case the plain meaning interpretation of “depth” is a dimension or distance as measured downwards from the top1. Moens discloses in the different embodiment of FIG. 9 the amended language under BRI as discussed below.
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 following newly added limitations must be shown or the feature(s) canceled from the claim(s):
Amended Claim 1 of the different depths for the source and drain contacts;
Newly added Claim 40 of the first depth of the first drain contact is greater than the second depth of the first source contact;
Newly added Claim 41 of the second depth of the first source contact is greater than the first depth of the first drain contact.
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.
(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 1,3,8,27-29,40-41,43-44 are rejected under 35 U.S.C. 102(a)(1) as being anticipated by US 2020/0219871 A1 to Moens et al., “Moens”.
Regarding claim 1, Moens discloses a semiconductor device (FIG. 9, ¶ [0059]-[0061]), comprising:
a silicon substrate layer (102, ¶ [0031]);
a first semiconductor layer (206, ¶ [0036], or alternately 106 and 206 together) comprising a gallium nitride layer, the first semiconductor layer (206) disposed over the silicon substrate layer (102);
a second semiconductor layer (208, ¶ [0036],[0039]) disposed on the first semiconductor layer (206), the second semiconductor layer comprising an aluminum gallium nitride layer, wherein a 2DEG channel (200, ¶ [0036],[0042],[0049]) is formed at an interface between the gallium nitride layer and the aluminum gallium nitride layer;
a first drain contact (right side, 922 and 908 together, ¶ [0059]-[0061]) extending through the second semiconductor layer (208) and extending into the first semiconductor layer (206), the first drain contact including a first portion (922) extended into the first semiconductor layer (208) and a second portion (908) extended laterally in the gallium nitride layer (206) such that the first drain contact extends to a first depth (e.g. depth from top of 206 to a deeper portion 9082, see Examiner-annotated figure below) within the gallium nitride layer (206); and
a first source contact (left side, 526 and 918 together, ¶ [0059]-[0060]) extending through the second semiconductor layer (208) and extending into the first semiconductor layer (206), the first source contact including a third portion (526) extended into the first semiconductor layer (206) and a fourth portion (918) extended in the gallium nitride layer such that the first source contact extends to a second depth within the gallium nitride layer (e.g. depth from top of 206 to top of 9184, see Examiner-annotated figure below), the second depth being different than the first depth.
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Examiner’s note: the phrase “extends to a depth” is interpreted under the doctrine of broadest reasonable interpretation (BRI, MPEP 2111) using the plain meaning interpretation of “depth” as a dimension or distance as measured downwards from the top.
Regarding claim 3, Moens discloses the semiconductor device of claim 1, and Moens further discloses (FIG. 9) a dielectric layer (300, ¶ [0043]) disposed on the second semiconductor layer (208), the dielectric layer (300) having at least one metallization layer (324, ¶ [0044]) embedded therein.
Regarding claim 8, Moens discloses the semiconductor device of claim 1, and Moens further discloses wherein the gallium nitride layer (106 and 206 together) comprises an undoped gallium nitride layer (206 may be unintentionally doped which one having ordinary skill in the art would recognize as undoped ¶ [0036]) disposed over a carbon doped gallium nitride layer (106 can include carbon ¶ [0033]).
Regarding claim 27, Moens discloses the semiconductor device of claim 1, and Moens further discloses wherein the second portion (908) of the first drain contact includes a doped semiconductor layer (¶ [0034]).
Regarding claim 28, Moens discloses the semiconductor device of claim 1, and Moens further discloses wherein the second portion (908) of the first drain contact includes a conductive channel with electrons or holes (holes since p-type, ¶ [0034]).
Regarding claim 29, Moens discloses the semiconductor device of claim 1, and Moens further discloses wherein the second portion (908) of the first drain contact extends laterally in the gallium nitride layer (206) at an angle that is perpendicular with respect to the first portion (922) of the first drain contact.
Regarding claim 40, Moens discloses the semiconductor device of claim 1, and Moens further discloses wherein the first depth of the first drain contact (at 9082, see Examiner-annotated figure with claim 1 above) is greater than the second depth (at 9184) of the first source contact.
Regarding claim 41, Moens discloses the semiconductor device of claim 1, and Moens further discloses wherein the second depth of the first source contact (depth from top of 206 to 9182, see Examiner-annotated figure below) is greater than the first depth (depth from top of 206 to 9084) of the first drain contact.
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Regarding claim 43, Moens discloses the semiconductor device of claim 1, and Moens further discloses wherein: the third portion (526) of the first source contact interfaces with the fourth portion (918) of the first source contact; and the fourth portion (918) of the first source contact extends in the gallium nitride layer (206) without extending laterally beyond the third portion (908) of the first source contact in the gallium nitride layer (206).
Regarding claim 44, Moens discloses the semiconductor device of claim 1, and Moens further discloses a gate structure (324, ¶ [0043]) disposed over the second semiconductor layer (208); and wherein the fourth portion (918) of the first source contact is positioned closer to the gate structure (324) than the second portion (908) of the first 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.
The factual inquiries for establishing a background for determining obviousness under 35 U.S.C. 103 are summarized as follows:
1. Determining the scope and contents of the prior art.
2. Ascertaining the differences between the prior art and the claims at issue.
3. Resolving the level of ordinary skill in the pertinent art.
4. Considering objective evidence present in the application indicating obviousness or nonobviousness.
Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over US 2020/0219871 A1 to Moens et al., “Moens”.
Regarding claim 2, although Moens anticipates the semiconductor device of claim 1, Moens fails to clearly state in sufficient specificity for anticipation (MPEP 2131.03) wherein the first portion of the first drain contact (922) extends between about 0.1 µm and about 10 µm into the first semiconductor layer (206).
However, Moens teaches wherein the first portion of the drain contact (922) extends through a substantial portion of the first semiconductor layer (206) and wherein the first semiconductor layer has a thickness in a range of 0.02 μm to 4 μm (20 nm to 4000 nm ¶ [0038]) which overlaps with the claimed range.
It would have been obvious before the effective filing date of the claimed invention to one having ordinary skill in the art to have formed the device of Moens with the depth of the first drain contact within the claimed range as suggested by the overlapping range of Moens since it has been held that in the case where the claimed ranges "overlap or lie inside ranges disclosed by the prior art" a prima facie case of obviousness exists. In re Wertheim, 541 F.2d 257, 191 USPQ 90 (CCPA 1976); In re Woodruff, 919 F.2d 1575, 16 USPQ2d 1934 (Fed. Cir. 1990), MPEP 2144.05, or since it has been held that “where the general conditions of a claim are disclosed in the prior art, it is not inventive to discover the optimum or workable ranges by routine experimentation.” In re Aller, 220 F.2d 454, 456, 105 USPQ 233, 235 (CCPA 1955), In re Hoeschele, 406 F.2d 1403, 160 USPQ 809 (CCPA 1969), wherein in the instant case the depth of the contact is determined by the thickness of the channel layer which determines the electrical characteristics such as the operating voltages of the transistor making it a result effective variable, In re Antonie, 559 F.2d 618, 195 USPQ 6 (CCPA 1977), and MPEP 2144.05 Obviousness of Ranges II. OPTIMIZATION OF RANGES A. Optimization Within Prior Art Conditions or Through Routine Experimentation B. Only Result-Effective Variables Can Be Optimized.
Claim 10 is rejected under 35 U.S.C. 103 as being unpatentable over US 2020/0219871 A1 to Moens et al., “Moens”, in view of US 2018/0138306 A1 to JEON et al., “Jeon”.
Regarding claim 10, although Moens discloses the semiconductor device of claim 1, Moens fails to clearly state wherein the first drain contact comprises a singular elongated drain contact.
Jeon teaches (FIG. 3A) a single elongated drain contact (“D” including 110D, ¶ [0029],[0031]-[0033],[0045]).
It would have been obvious before the effective filing date of the claimed invention to one having ordinary skill in the art to have formed the device of Moens with the drain contact elongated as exemplified by Jeon such that ohmic contact of the drain is not adversely affected (¶ [0042], i.e. resistance is decreased by maximizing contact area, and an elongated drain maximizes contact area).
Claim 30 is rejected under 35 U.S.C. 103 as being unpatentable over US 2020/0219871 A1 to Moens et al., “Moens”, in view of US 6,329,677 B1 to Oguri et al., “Oguri”.
Regarding claim 30, although Moens discloses the semiconductor device of claim 1, Moens fails to clearly teach in sufficient detail for anticipation wherein the first portion of the first drain contact has a first side and an opposing second side, the second portion of the first drain contact is disposed on the first side of the first portion of the first drain contact without being disposed on the second side of the first portion of the first drain contact.
Oguri teaches wherein a first portion (“DR”, column 4 lines 10-13) of a drain contact has a first side and an opposing second side, and a second portion (“DM”, column 4 lines 24-37) of the first drain contact is disposed on the first side of the first portion of the first drain contact without being disposed on the second side of the first portion of the drain contact (as pictured).
It would have been obvious before the effective filing date of the claimed invention to one having ordinary skill in the art to have formed the device of Moens with the second portion of the drain contact only extending in towards and under the transistor's channel as exemplified by Oguri since the second portion of the drain contact (Moens buried region 108) functions to inject holes into the channel and improve the on-state resistance (Moens ¶ [0049]) and the 2DEG channel exists on the first side of the drain contact without being disposed on the second side of the drain contact (i.e. the channel spans from the drain to the source contact). Alternately it would have been obvious before the effective filing date of the claimed invention to one having ordinary skill in the art to have formed the device of Moens with the second portion of the drain contact only extending in towards and under the transistor's channel as taught by Oguri in order to selectively enhance the channel performance and improve the breakdown voltage (Oguri column 3 lines 7-20, column 4 lines 30-37).
Allowable Subject Matter
Claims 22,34,36-39 are allowed.
Claims 9,31,42 are objected to as being dependent upon a rejected base claim, but would be allowable if rewritten in independent form including all of the limitations of the base claim and any intervening claims.
The following is a statement of reasons for the indication of allowable subject matter:
Prior art e.g. Moens teaches a structuring including source and drain terminals as discussed above.
Prior art e.g. US 2021/0202730 A1 to Hao et al. discloses a structure (FIG. 1A), comprising:
a gallium nitride layer (103, ¶ [0023]) disposed on a silicon substrate (101, ¶ [0019]);
an aluminum gallium nitride layer (104, ¶ [0027]) disposed on the gallium nitride layer, wherein a 2DEG channel (¶ [0035]) is formed at an interface between the gallium nitride layer and the aluminum gallium nitride layer;
a silicon nitride layer (105, ¶ [0036]) disposed on the aluminum gallium nitride layer;
at least one metallization layers disposed in the silicon nitride layer, the at least one metallization layers forming a drain electrode (e.g. upper portion of 107, similar to Applicant’s use of the term e.g. Applicant’s ¶ [0031]), a gate electrode (106), and a source electrode (e.g. upper portion of 108, similar to Applicant’s use of the term e.g. Applicant’s ¶ [0031]); and at least one drain terminal (107 and 103’ together, ¶ [0018],[0024]) coupled to the drain electrode, the at least one drain terminal (i.e. structure connected to drain) including a first portion (107) extended through the silicon nitride layer (105) and aluminum gallium nitride layer (104) and into the gallium nitride layer (103) and a second portion (103’, ¶ [0024]) extended laterally in the gallium nitride layer (103), as discussed previously.
Prior art e.g. US 2021/0126120 A1 to Piedra et al. teaches (e.g. Figure 4) wherein at least one drain terminal (424 and 420) coupled to a drain electrode, the at least one drain terminal including a first metal portion (424) extended through a stacked structure (414) and into the substrate (402) and a second metal portion (404, “the conductive layers can include metallic materials” ¶ [0025]) extended laterally in the substrate, and source terminal including a third metal portion (426) extended through the stack (414) and into the substrate (402) and a fourth metal portion (406) extended laterally beyond the third metal portion.
However, prior art fails to reasonably teach or suggest at least one drain terminal coupled to the drain electrode, the at least one drain terminal including a first metal portion extended through the silicon nitride layer and aluminum gallium nitride layer and into the gallium nitride layer and a second metal portion extended laterally in the gallium nitride layer; and a source terminal coupled to the source electrode, the source terminal including a third metal portion extended through the silicon nitride layer and the aluminum gallium nitride layer and into the gallium nitride layer and a fourth metal portion extended laterally beyond the third metal portion in the gallium nitride layer, together with all of the limitations of claim 22. Claims 34,36-39 are allowable insofar as they depend upon and include all of the limitations of allowable claim 22.
Claim 31 and 42 are object to as being allowable for similar reasons to claim 22.
Claim 9 is objected to as although Moens teaches the limitations of claims 1 and 8 as discussed above, Moens teaches in paragraph [0052]: “The relatively thicker portions of the buried regions 508 and 518 may allow for more process margin when forming the drain and source electrodes 322 and 526 to reduce the likelihood of etching through the buried regions 508 and 518 and reaching the buffer layer 106” and therefore fails to reasonably teach or suggest wherein the first drain contact extends through the undoped gallium nitride layer and into the carbon doped gallium nitride layer together with all of the limitations of claims 8 and 1.
Conclusion
Applicant's amendment necessitated the new ground(s) of rejection presented in this Office action. 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 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 ERIC A WARD whose telephone number is (571)270-3406. The examiner can normally be reached M-F 10-6 ET.
Examiner interviews are available via telephone, in-person, and video conferencing using a USPTO supplied web-based collaboration tool. To schedule an interview, applicant is encouraged to use the USPTO Automated Interview Request (AIR) at http://www.uspto.gov/interviewpractice.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Matthew Landau can be reached at (571)272-1731. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/Eric A. Ward/Primary Examiner, Art Unit 2891
1 Oxford English Dictionary, “depth (n.), sense II.i.7.a,” June 2026, https://doi.org/10.1093/OED/8399456556.
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