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 .
Priority
Receipt is acknowledged of certified copies of papers required by 37 CFR 1.55.
However, should applicant desire to obtain the benefit of foreign priority under 35 U.S.C. 119(a)-(d) prior to declaration of an interference, a certified English translation of the foreign application must be submitted in reply to this action. 37 CFR 41.154(b) and 41.202(e).
Failure to provide a certified translation may result in no benefit being accorded for the non-English application.
Information Disclosure Statement
The information disclosure statement (IDS) filed on April 4th, 2024, is being considered by the examiner.
Claim Objections
Claims 9-12 are objected to because of the following informalities:
Regarding Claim 9, in line 11 the claim recites “a region on a more lower surface side of the first layer than the near-interfacial region” where, with careful interpretation in light of the specification, one can infer or deduce that the Applicant means some region of the first layer below, or closer to the surface or substrate, with respect to the position of the near-interfacial region in the first layer. More lower is not only relatively indefinite, but also grammatically incorrect. Further, Claim 9 line 13 recites “the lowest value” where there is no previous introduction of a lowest value; however, one can infer that the Applicant is referring to “the lowest concentration” which was previously introduced in line 9.
The Examiner suggests a clearer set of claim language based on the example set out in claim 1, FIGs. 2 and 4, and paragraph [0074] to address both minor informalities, such as the interpretation below:
Claim 9: The group III nitride multilayered structure according to claim 1, wherein a second peak concentration higher than a lowest concentration of the impurity in the near-interfacial region exists in a region on a and below the near-interfacial region, and a ratio of the lowest concentration to the second peak concentration is 1/30 or more.
Appropriate correction is required.
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.
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.
Claims 1 and 3-15 are rejected under 35 U.S.C. 103 as being unpatentable over Laboutin et al., US PGPub 2015/0001582 A1 (hereinafter referred to as “Laboutin”) in view of Ishiguro et al., US PGPub 2019/0020318 A1 (hereinafter referred to as “Ishiguro”).
Regarding Claim 1, Laboutin discloses a group III nitride multilayered structure (FIG. 3; [0018]), comprising:
a first layer comprising a group III nitride (FIG. 3, iron-doped layer 331; [0018-0019]);
and a third layer disposed on the second layer and comprising a group III nitride (FIG. 3, channel layer 34; [0018, 0021]),
wherein the first layer contains an impurity that makes the group III nitride electrically highly resistive at least in a near-interfacial region (FIGs. 3, 4, iron-doped layer 331; [0019]), which is a region with a thickness of 50 nm from an interface between the first layer and the second layer (see annotated FIG. 4, blue-dashed box indicating thickness and position of a near-interfacial region),
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a concentration of the impurity is lower on a third layer side than on a first layer side interposing the second layer therebetween (see annotated FIG. 4, annotation C5 and black-dashed box indicated the thickness of channel layer 34),
and in the third layer, the concentration of the impurity reaches less than 2×1015 cm -3 continuously over a thickness of at least 3 nm, so that the third layer is substantially free of the impurity (see annotated FIG. 4, annotation C5; [0019, 0021]).
Laboutin discloses a second layer disposed on the first layer and comprising a group III nitride, (Laboutin FIG. 3, iron-doping-stop layer 332), but does not disclose containing In;
However, Ishiguro, which is directed to a similar group III nitride multilayer with similar impurity doping as used in Laboutin, teaches that an In-containing group III nitride can also be used as a second layer (Ishiguro FIGs. 2, 3, 4, back barrier layer 2c, [0054-0055]) for the purpose of solving the same problem as the second layer of Laboutin: to prevent diffusion of the impurity (in both cases, Fe) to the channel layer and causing issues with off current leakage. Both the layer taught by Laboutin as well as the layer taught by Ishiguro solve this problem and both layers are disposed on the same type of first layer with the same impurity element and extremely similar impurity concentration profiles (Laboutin FIGs. 3, 4, iron-doping-stop layer 332, [0019]; Ishiguro FIGs. 2, 3, 4, back barrier layer 2c, [0054-0055]).
Therefore, it would have been known and obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that simply substituting the second layer of Laboutin with the In-containing group III nitride second layer of Ishiguro would have the known and predictable results of preventing Fe diffusion.
Regarding Claim 3, Laboutin in view of Ishiguro (Laboutin/Ishiguro) discloses the group III nitride multilayered structure according to claim 1, as discussed above.
Laboutin further discloses wherein a lowest concentration of the impurity in the near-interfacial region is 2×1016 cm-3 or more (see annotated FIG. 4 above; lowest concentration in iron-doped layer 331 is about 7E17 cm-3, annotation C4 in blue-dashed box, representing a near-interfacial region of the first layer).
Regarding Claim 4, Laboutin/Ishiguro discloses the group III nitride multilayered structure according to claim 1, as discussed above.
Laboutin further discloses wherein the concentration of the impurity increases toward the second layer in the near-interfacial region, after the increase, the concentration of the impurity reaches a first peak concentration; and a ratio of 2 x 1015 cm-3 to the first peak concentration is 1/150 or less, which is a reduction ratio when the concentration of the impurity is decreased from the first peak concentration to 2 x 1015 cm-3 (see annotated FIG. 4 above, Fe concentration increases in blue-dashed box, representing a near-interfacial region of the first layer, and reaches peak in orange-dashed box, representing the second layer, with a peak concentration at annotation C1 and [0019] of 7E18 cm-3 which gives a reduction ratio of 2E15 cm-3 to C1 of 1/3500, which is less than 1/150).
Regarding Claim 5, Laboutin/Ishiguro discloses the group III nitride multilayered structure according to claim 1, as discussed above.
Laboutin further discloses wherein the concentration of the impurity increases toward the second layer in the near-interfacial region (see annotated FIG. 4, Fe concentration profile increases in the blue-dashed box, representing a near-interfacial region of the first layer, toward the second layer);
after the increase, the concentration of the impurity reaches a first peak concentration (see annotated FIG. 4, Fe concentration profile reaches a peak C1 in the orange-dashed box, representing the second layer);
and an average decreasing slope when the concentration of the impurity decreases from the first peak concentration to 2 x 1015 cm -3, is 2.5 x 1016 cm-3 / nm or more (see annotated FIG. 4, the Fe concentration then decreases from a peak C1 over a range of about 25nm to below 2E15 cm-3 in black-dashed box, representing the thickness of the third layer, the channel layer 34 from [0021]; an average decreasing slope of about 2.8E17 cm-3).
Regarding Claim 6, Laboutin/Ishiguro discloses the group III nitride multilayered structure according to claim 1, as discussed above.
Laboutin further discloses wherein in the third layer, an average concentration of the impurity in an upper 10 nm thickness range from a thickness position of 10 nm from an interface with the second layer, is less than 3 x 1015 cm-3 (see annotated FIG. 4, Fe concentration profile in the black dashed box, representing the thickness of the third layer, the channel layer 34 from [0021]; the entire range of the channel layer 34 is below 3E15 cm-3 including an upper 10nm from the orange-dashed box, i.e., the second layer).
Regarding Claim 7, Laboutin/Ishiguro discloses the group III nitride multilayered structure according to claim 1, as discussed above.
Laboutin further discloses wherein the concentration of the impurity in an upper surface of the third layer is lower than a lowest concentration of the impurity in the near-interfacial region of the first layer (see annotated FIG. 4, annotation C5 showing a concentration in an upper surface of the black-dashed box, representing the third layer, is below 2E15 cm-3 and therefore lower than a lowest concentration in the blue-dashed box, representing a near-interfacial region of the first layer, shown with annotation C4 at about 7E17 cm-3).
Regarding Claim 8, Laboutin/Ishiguro discloses the group III nitride multilayered structure according to claim 1 as discussed above.
Laboutin further discloses wherein the concentration of the impurity in the first layer reaches a highest value at an interface with the second layer (see annotated FIG. 4, the blue-dashed box, representing a near-interfacial region of the first layer, and annotation C2 pointing out the concentration at the interface with the orange-dashed box, representing the second layer).
Regarding Claim 9, Laboutin/Ishiguro discloses the group III nitride multilayered structure according to claim 1, as discussed above.
Laboutin further discloses wherein a second peak concentration higher than a lowest concentration of the impurity in the near-interfacial region exists in a region on a more lower surface side of the first layer than the near-interfacial region, and a ratio of the lowest value to the second peak concentration is 1/30 or more (see annotated FIG. 4, a second peak concentration in a region on a more lower surface side of the first layer seen in annotation C3 of about 1E18 cm-3 is higher than a lowest concentration in the blue-dashed box, representing a near-interfacial region of the first layer, seen in annotation C4 of about 7E17 cm-3; a ratio of the lowest concentration to the second peak concentration is about 0.7 which is more than 1/30 (0.03)).
Regarding Claim 10, Laboutin/Ishiguro discloses the group III nitride multilayered structure according to claim 1, as discussed above.
Laboutin further discloses wherein a second peak concentration higher than a lowest concentration of the impurity in the near-interfacial region exists in a region on more lower surface side of the first layer than the near-interfacial region (see annotated FIG. 4, annotation C3 in the purple-dashed box, representing the first layer, i.e., the iron-doped layer 331, [0019]);
and a thickness of the first layer from a thickness position where the second peak concentration exists to an interface with the second layer, is thinner than a thickness of the first layer from a lower surface of the first layer to the thickness position where the second peak concentration exists (see annotated FIG. 4, where a green-dashed box, representing a thickness from a second peak concentration, C3, to the second layer, is smaller than the purple-dashed box, representing the total thickness of the first layer, i.e., iron-doped layer 331).
Regarding Claim 11, Laboutin/Ishiguro discloses the group III nitride multilayered structure according to claim 1, as discussed above.
Laboutin further discloses wherein a second peak concentration higher than a lowest concentration of the impurity in the near-interfacial region exists in a region on more lower surface side of the first layer than the near-interfacial region (see annotated FIG. 4, annotation C3 in the purple-dashed box, representing the first layer, i.e., the iron-doped layer 331, [0019]);
and a thickness of the first layer from a thickness position where the second peak concentration exists to an interface with the second layer, is 250 nm or less (see annotated FIG. 4, a green-dashed box, representing a thickness from a second peak concentration C3, to the second layer is 250nm or less).
Regarding Claim 12, Laboutin/Ishiguro discloses the group III nitride multilayered structure according to claim 1, as discussed above.
Laboutin further discloses wherein a concentration of the impurity increases toward the second layer in the near-interfacial region (see annotated FIG. 4, Fe concentration profile increases in the blue-dashed box, representing a near-interfacial region of the first layer, toward the second layer);
after the increase, the concentration of the impurity reaches a first peak concentration (see annotated FIG. 4, Fe concentration profile reaches a peak C1 in the orange-dashed box, representing the second layer);
a second peak concentration higher than a lowest concentration of the impurity in the near-interfacial region exists in a region on a more lower surface side of the first layer than the near-interfacial region (see annotated FIG. 4, annotation C3 in the purple-dashed box, representing the first layer, i.e., the iron-doped layer 331, [0019]);
and the first peak concentration is higher than the second peak concentration (see annotated FIG. 4, annotation C1 is higher than annotation C3).
Regarding Claim 13, Laboutin/Ishiguro discloses the group III nitride multilayered structure according to claim 1, as discussed above.
Laboutin further discloses wherein the group III nitride multilayered structure is included as part of a high electron mobility transistor, and the third layer is a channel layer of the high electron mobility transistor (FIG. 3, channel layer 34; [0011, 0018, 0021]).
Regarding Claim 14, Laboutin/Ishiguro discloses the group III nitride multilayered structure according to claim 1, as discussed above.
Laboutin further discloses wherein the first layer is a free-standing substrate comprising a group III nitride (FIG. 3, substrate 31; [0020]).
Regarding Claim 15, Laboutin/Ishiguro discloses the group III nitride multilayered structure according to claim 1, as discussed above.
Laboutin further discloses wherein the impurity is a transition metal (FIG. 3, iron-doped layer 331; abstract, [0005, 0015]).
Claim 2 is rejected under 35 U.S.C. 103 as being unpatentable over Laboutin/Ishiguro in further view of Kiyoku et al., US Patent No. 6153010 A (hereinafter referred to as “Kiyoku”).
Regarding Claim 2, Laboutin/Ishiguro discloses the group III nitride multilayered structure according to claim 1, as discussed above.
Neither Laboutin nor Ishiguro explicitly disclose wherein the second layer comprises a group III nitride having an In composition of more than 15%, although Ishiguro teaches an Indium composition of 5-15%, it does not explicitly teach more than 15%.
However, Kiyoku is directed to a similar group III nitride multilayer structure and the manufacture thereof and teaches the structure have Indium containing layers, similar that taught by Laboutin in view of Ishiguro, wherein the Indium containing layers have Indium concentrations of up to 50% for the benefit of crack prevention (Col. 21 lines 47-53).
Therefore, it would have been obvious before the effective filing date of the claimed invention to combine the structure of Laboutin/Ishiguro with the teachings of Kiyoku to change the Indium composition such that the group III nitride having an In composition of more than 15% for the benefit of crack prevention from lattice mismatches (Col. 21, lines 47-53).
Claims 16, 18 and 17, 19 are rejected under 35 U.S.C. 103 as being unpatentable over Laboutin/Ishiguro.
Regarding Claim 16, Laboutin discloses a high electron mobility transistor (FIG. 3; [0018]) including:
a first layer comprising a group III nitride (FIG. 3, iron-doped layer 331; [0018-0019]);
a second layer disposed on the first layer and comprising a group III nitride containing In;
and a third layer disposed on the second layer, comprising a group III nitride, and being a channel layer of the high electron mobility transistor (FIG. 3, channel layer 34; [0018, 0021]),
wherein the first layer contains an impurity that makes the group III nitride electrically highly resistive at least in a near-interfacial region (FIGs. 3, 4, iron-doped layer 331; [0019]), which is a region with a thickness of 50 nm from an interface between the first layer and the second layer (see annotated FIG. 4, blue-dashed box indicating thickness and position of a near-interfacial region),
a concentration of the impurity increases toward the second layer in the near-interfacial region (see annotated FIG. 4, Fe concentration profile increases in the blue-dashed box, representing a near-interfacial region of the first layer, toward the second layer);
after the increase, the concentration of the impurity reaches a first peak concentration of 3 x 1017 cm-3 or more (see annotated FIG. 4, Fe concentration profile reaches a peak C1 of 7E18 cm-3 in the orange-dashed box, representing the second layer, [0019]),
the concentration of the impurity is lower on a third layer side than on a first layer side interposing the second layer therebetween (see annotated FIG. 4, annotation C5 and black-dashed box indicated the thickness of channel layer 34),
Laboutin discloses a second layer disposed on the first layer and comprising a group III nitride, (Laboutin FIG. 3, iron-doping-stop layer 332), but does not disclose containing In;
However, Ishiguro, which is directed to a similar group III nitride multilayer with similar impurity doping as used in Laboutin, teaches that an In-containing group III nitride can also be used as a second layer (Ishiguro FIGs. 2, 3, 4, back barrier layer 2c, [0054-0055]) for the purpose of solving the same problem as the second layer of Laboutin: to prevent diffusion of the impurity (in both cases, Fe) to the channel layer and causing issues with off current leakage. Both the layer taught by Laboutin as well as the layer taught by Ishiguro solve this problem and both layers are disposed on the same type of first layer with the same impurity element and extremely similar impurity concentration profiles (Laboutin FIGs. 3, 4, iron-doping-stop layer 332, [0019]; Ishiguro FIGs. 2, 3, 4, back barrier layer 2c, [0054-0055]).
Therefore, it would have been known and obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that simply substituting the second layer of Laboutin with the In-containing group III nitride second layer of Ishiguro would have the known and predictable results of preventing Fe diffusion.
Neither Laboutin nor Ishiguro explicitly disclose and a sheet resistance of the high electron mobility transistor is less than 1.1 times a sheet resistance of a high electron mobility transistor in which the second layer is omitted and the first layer is free of the impurity.
However, the sheet resistance is an intrinsic and inherent property of the as-designed high electron mobility transistor—it will fully depend upon the layer design, placement, and impurity concentrations therein. Laboutin/Ishiguro discloses the same structure and impurity concentration profile as the claimed invention.
Therefore, the sheet resistance of Laboutin/Ishiguro would inherently fulfill the claimed value of less than 1.1 times a sheet resistance of a high electron mobility transistor in which the second layer is omitted and the first layer is free of the impurity.
Regarding Claim 18, Laboutin/Ishiguro discloses the high electron mobility transistor according to claim 16, as discussed above.
Laboutin further discloses wherein the first peak concentration is 3×1018 cm-3 or more (see annotated FIG. 4, annotation C1 showing concentration of about 7E18 cm-3; [0019]).
Regarding Claim 17, Laboutin discloses a high electron mobility transistor (FIG. 3; [0018]) including:
a first layer comprising a group III nitride (FIG. 3, iron-doped layer 331; [0018-0019]);
and a third layer disposed on the second layer, comprising a group III nitride, and being a channel layer of the high electron mobility transistor (FIG. 3, channel layer 34; [0018, 0021]),
wherein the first layer contains an impurity that makes the group III nitride electrically highly resistive at least in a near-interfacial region (FIGs. 3, 4, iron-doped layer 331; [0019]), which is a region with a thickness of 50 nm from an interface between the first layer and the second layer (see annotated FIG. 4, blue-dashed box indicating thickness and position of a near-interfacial region),
a concentration of the impurity increases toward the second layer in the near-interfacial region (see annotated FIG. 4, Fe concentration profile increases in the blue-dashed box, representing a near-interfacial region of the first layer, toward the second layer);
after the increase, the concentration of the impurity reaches a first peak concentration of 3 x 1017 cm-3 or more (see annotated FIG. 4, Fe concentration profile reaches a peak C1 of 7E18 cm-3 in the orange-dashed box, representing the second layer, [0019]),
the concentration of the impurity is lower on a third layer side than on a first layer side interposing the second layer therebetween (see annotated FIG. 4, annotation C5 and black-dashed box indicated the thickness of channel layer 34),
Laboutin discloses a second layer disposed on the first layer and comprising a group III nitride, (Laboutin FIG. 3, iron-doping-stop layer 332), but does not disclose containing In;
However, Ishiguro, which is directed to a similar group III nitride multilayer with similar impurity doping as used in Laboutin, teaches that an In-containing group III nitride can also be used as a second layer (Ishiguro FIGs. 2, 3, 4, back barrier layer 2c, [0054-0055]) for the purpose of solving the same problem as the second layer of Laboutin: to prevent diffusion of the impurity (in both cases, Fe) to the channel layer and causing issues with off current leakage. Both the layer taught by Laboutin as well as the layer taught by Ishiguro solve this problem and both layers are disposed on the same type of first layer with the same impurity element and extremely similar impurity concentration profiles (Laboutin FIGs. 3, 4, iron-doping-stop layer 332, [0019]; Ishiguro FIGs. 2, 3, 4, back barrier layer 2c, [0054-0055]).
Therefore, it would have been known and obvious to one of ordinary skill in the art before the effective filing date of the claimed invention that simply substituting the second layer of Laboutin with the In-containing group III nitride second layer of Ishiguro would have the known and predictable results of preventing Fe diffusion.
Neither Laboutin nor Ishiguro explicitly disclose and a magnitude of threshold voltage of the high electron mobility transistor is more than 0.9 times compared to a magnitude of threshold voltage of the high electron mobility transistor in which the second layer is omitted and the first layer is free of the impurity.
However, the threshold voltage is an intrinsic and inherent property of the as-designed high electron mobility transistor—it will fully depend upon the layer design, placement, and impurity concentrations therein. Laboutin/Ishiguro discloses the same structure and impurity concentration profile as the claimed invention.
Therefore, the threshold voltage of Laboutin/Ishiguro would inherently fulfill the claimed value of more than 0.9 times compared to a magnitude of threshold voltage of the high electron mobility transistor in which the second layer is omitted and the first layer is free of the impurity.
Regarding Claim 19, Laboutin/Ishiguro discloses the high electron mobility transistor according to claim 17, as discussed above.
Laboutin further discloses wherein the first peak concentration is 3 x 1018 cm-3 or more (see annotated FIG. 4, annotation C1 showing concentration of about 7E18 cm-3; [0019]).
Conclusion
The prior art made of record and not relied upon is considered pertinent to applicant's disclosure:
Yokoyama, US PGPub 2010/0244098 A1, which is directed to a similar multilayer group III nitride structure wherein comprising a buffer layer made highly resistive through transition metal doping and multiple back barrier layers help prevent diffusion.
Ishiguro et al., US PGPub 2018/0069086 A1, which is directed to a similar multilayer group III nitride structure comprising a buffer layer made highly resistive through transition metal doping and a back barrier layer to prevent diffusion.
Eriguchi et al., US PGPub 2021/0028284 A1, which is directed to a similar multilayer group III nitride structure comprising a buffer layer made highly resistive through transition metal doping.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to Austin T. Woodard whose telephone number is (571)270-1958. The examiner can normally be reached M-F, 8am to 5pm ET.
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If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Sue Purvis can be reached at (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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/Austin T Woodard/Examiner, Art Unit 2893
/SUE A PURVIS/Supervisory Patent Examiner, Art Unit 2893
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