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 of claims 11-19 without traverse in the reply filed on 02/12/2026 is acknowledged. Claims 20 withdrawn by applicant. New claim 21 directed to method claim falls under group II, and therefore, withdrawn from further consideration pursuant to 37 CFR 1.142(b) as being drawn to a nonelected invention, there being no allowable generic or linking claim.
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 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 teaches d 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 11-12, 16-19 are rejected under 35 U.S.C. 103 as being unpatentable over LaRoche et al. (US 11,515,410 B2) in view of Romano et al. (US 2013/0126884 A1) in view of Hsiung et al. (US 2013/0112986 A1).
Regarding claim 11, LaRoche teaches,
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A vertical semiconductor component (Fig. 1’)……., comprising:
a semiconductor substrate (12 which may be formed of Si or SiC, Col. 5, ll. 56-57) which has a front face and a rear face (top and bottom face of 12), the front face being opposite the rear face, the semiconductor substrate having first chemical elements (Si as first chemical elements as per page 9, line 20-21 of disclosure for Si substrate. Alternatively, first chemical elements may be Si and C for SiC substrate);
a buffer layer (buffer layer 14b, Col. 5, l. 59, which may be formed of GaN layer, Col. 7, l. 29) which is arranged on the front face of the semiconductor substrate (as seen), the buffer layer having second chemical elements (Ga, N);
a semiconductor contact layer (doped group III-V layer 20 which may be GaN doped with silicon, Col. 6, ll. 10-12) which is arranged on the buffer layer,
an active region (active device region 9, col. 5, l. 45) of the vertical semiconductor component being arranged on the semiconductor contact layer;
and an etching control layer (Group III-N barrier layer 18 which may be AlGaN, Col. 5, ll. 66-67, col. 6, l. 1) arranged between the buffer layer and the semiconductor contact layer,
But LaRoche does not explicitly teach,
……for generating an abrupt end point detection signal,
AlGaN barrier layer 18 is an etching control layer and the etching control layer having at least one third chemical element which differs from the first chemical elements and the second chemical elements.
Meanwhile, Romano teaches,
the AlGaN may be etch stop layer and can be doped to form a p-type layer, an n-type layer, or can be undoped depending on the device application (para [0021]).
And Hsiung teach,
the group III-V semiconductor material may comprise GaN, AlGaN, or InGaN and may be doped with a p-type dopant such as magnesium (Mg), calcium (Ca), zinc (Zn), beryllium (Be), or carbon (C) (para [0037]).
Thus, it would have been obvious to try by one of ordinary skill in the art before the effective filing date of the claimed invention to form AlGaN doped with magnesium as a material for the AlGaN barrier layer 18, according to the teaching of Hsiung (such that third chemical element includes magnesium (Mg) which differs from the first chemical elements (Si) and second chemical elements (Ga, N), according to teaching of Romano & Hsiung above, in order to form AlGaN barrier layer 18 as an etch stop/control layer for the purpose of forming a desired device application, as taught by Romano above, since it has been held that choosing from a finite number of identified, predictable solutions such as AlGaN doped with magnesium as an etch stop layer, with a reasonable expectation of success is obvious. KSR Int'l v. Teleflex Inc., 127 S.Ct. 1727 (2007).
Laroche, Romano & Hsiung still do not explicitly teach,
……for generating an abrupt end point detection signal,
However, the above claim limitation “for generating an abrupt end point detection signal” does not distinguish the present invention over the prior art of Laroche in view of Romano in view of Hsiung who teaches the structure as claimed. Moreover, it has been held that a recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus satisfying the claimed structural limitations. Ex parte Masham, 2 USPQ 2d 1647 (1987).
Regarding claim 12, Laroche, Romano & Hsiung teach the vertical semiconductor component of claim 11 and further teach, wherein the third chemical element includes germanium, or magnesium, or iron or indium (third chemical element is magnesium as per claim 11 rejection above).
Regarding claim 16, Laroche, Romano & Hsiung teach the vertical semiconductor component of claim 11 but does not explicitly teach, wherein the etching control layer has a layer thickness between 20 nm and 200 nm.
But Romano additionally teaches,
the thickness of the AlGaN etch stop layer can range from about 1 nm to about 30 nm (para [0027]).
However, it is to be noted here that the claimed range of between 20 nm and 200 nm and the range 1 nm to 20 nm taught by Romano overlaps each other. In the case where the claimed ranges “overlap or lie inside ranges teaches d 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).
Regarding claim 17, Laroche, Romano & Hsiung, teach the vertical semiconductor component of claim 11 and further teaches, wherein the first chemical elements include: i) silicon (first chemical element may include silicon as asserted in claim 1 rejection above) , or ii) silicon and boron, or iii) silicon and phosphorus, or iv) silicon and arsenic, or v) silicon and antimony,
but does not explicitly teach,
and the second chemical elements include aluminum and gallium and nitrogen.
But as per claim 11 rejection,
buffer layer 14b formed of GaN which is a group III-V semiconductor material.
and Hsiung teaches,
the group III-V semiconductor material may comprise GaN, AlGaN, or InGaN (see para [0037]
Thus, it would have been obvious to one of ordinary skill in the art before the effective filing date of the claimed invention to substitute GaN with AlGaN as a material for the buffer layer 14b (such that second chemical elements of 14b includes aluminum, gallium and nitrogen) , since the court has held that a simple substitution of one known element for another (AlGaN for GaN) to obtain predictable results is obvious. KSR Int'l v. Teleflex Inc., 127 S.Ct. 1727 (2007). (Please see Smith v. Hayashi, 209 USPQ 754 (Bd. of Pat. Inter. 1980)).
Ordinary artisan would have been motivated to do this substitution in order to simplify the material choice of buffer layer 14b and etch control layer 18 which is made of AlgaN).
Regarding claim 18, Laroche, Romano & Hsiung teach the vertical semiconductor component of claim 11 and further teaches, wherein the vertical semiconductor component includes gallium nitride (as per claim 11 rejection above, buffer layer includes GaN).
Regarding claim 19, Laroche, Romano & Hsiung teach the vertical semiconductor component of claim 11 and further teaches, wherein the vertical semiconductor component is a Schottky diode (gate electrode 15 in schottky contact with barrier layer 18, see Laroche, Col. 6, ll. 43-48., and hence forms a schottky diode), or a pn diode, or a vertical diffusion MOSFET, or a planar gate MOSFET, or a trench gate MOSFET, or a current aperture vertical electron transistor, or a vGroove HEMT, or a FinFET.
Claim 13-15 are rejected under 35 U.S.C. 103 as being unpatentable over LaRoche et al. (US 11,515,410 B2) in view of Romano (US 2013/0126884 A1) in view of Hsiung et al. (US 2013/0112986 A1) in view of KAMATA (JP-2005260047-A) in view of Odnoblyudov et al. (US-20180204941-A1) in view of SMITH et al.( US-20220367695-A1).
Regarding claim 13, LaRoche teaches,
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A vertical semiconductor component (Fig. 1’)……….., comprising:
a semiconductor substrate (12 maybe formed of Si, Col. 5, ll. 56-57) which has a front face and a rear face, the front face being opposite the rear face,
the semiconductor substrate having first chemical elements (Si as first chemical elements as per page 9, ll. 20-21 of the disclosure)……,
a buffer layer (buffer layer 14b, Col. 5, l. 59, which may be formed of GaN layer, Col. 7, l. 29) which is arranged on the front face of the semiconductor substrate, the buffer layer having second chemical elements (Ga, N)……….;
a semiconductor contact layer (doped group III-V layer 20 which may be GaN doped with silicon, Col. 6, ll. 10-12) which is arranged on the buffer layer,
an active region (active device region 9, col. 5, l. 45) of the vertical semiconductor component being arranged on the semiconductor contact layer; and
an etching control layer (Group III-N barrier layer 18 which may be AlGaN, Col. 5, ll. 66-67, col. 6, l. 1) arranged between the buffer layer and the semiconductor contact layer (as seen)……
But LaRoche does not explicitly teach,
……for generating an abrupt end point detection signal,
AlGaN barrier layer 18 is an etch control layer,
and the semiconductor substrate (12) having a further chemical element with a first background concentration,
the buffer layer (14b) having the further chemical element with a second background concentration,
the etching control layer having the further element with a third background concentration, the third background concentration being greater than the first background concentration and the second background concentration.
Meanwhile, Romano teaches,
the AlGaN may be etch stop layer and can be doped to form a p-type layer, an n-type layer, or can be undoped depending on the device application (para [0021]).
And Hsiung teach,
the group III-V semiconductor material may comprise GaN, AlGaN, or InGaN and may be doped with a p-type dopant such as magnesium (Mg), calcium (Ca), zinc (Zn), beryllium (Be), or carbon (C) (para [0037]).
Thus, it would have been obvious to try by one of ordinary skill in the art before the effective filing date of the claimed invention to modify LaRoche such that AlGaN barrier layer 18 is doped with magnesium , according to teaching of Romano & Hsiung, in order to form the AlgaN barrier layer 18 as an etch stop/control layer for the purpose of forming a desired device application, as taught by Romano since it has been held that choosing from a finite number of identified, predictable solutions such as AlGaN doped with magnesium as a material for doped group III-N material, with a reasonable expectation of success is obvious. KSR Int'l v. Teleflex Inc., 127 S.Ct. 1727 (2007).
Laroche, Romano & Hsiung still do not explicitly teach,
……for generating an abrupt end point detection signal,
and the semiconductor substrate (Si substrate 12) having a further chemical element with a first background concentration,
the buffer layer (GaN layer 14b) having the further chemical element with a second background concentration
the etching control layer (AlGaN barrier layer 18) having the further element with a third background concentration, the third background concentration being greater than the first background concentration and the second background concentration.
Meanwhile, KAMATA teaches,
background concentration in silicon substrate maybe 3 × 1015 cm3 for carbon (see highlighted texts in attached english equivalent document of KAMATA).
And Odnoblyudov teaches,
GaN may have a background doping levels (free carrier density) of carbon on the order of 1×1012 cm-3 (para [0029]).
And SMITH teaches,
AlGaN may have background impurity level of carbon with less than 1x1017 cm-3, less than 5x1016 cm-3, less than 1x1016 cm-3, or less than 1x1015 cm-3 (para [0197]).
Thus, it would have been obvious to one of the ordinary skills in the art before the effective filing date of the claimed invention to vary the background concentrations of carbon in Silicon substrate, GaN buffer layer and AlGaN etching control layer, with routine experiment and optimization (such that third background concentration of the further chemical element (carbon) in AlGaN etching control layer 18 being greater than the first background concentration of carbon in Si substrate 12 and the second background concentration of carbon in GaN buffer layer 14b), since background concentration of impurity (e.g. carbon) is important in order to achieve desired etch selectivity of the etch control layer 18 (with respect to GaN buffer layer 14b and Si substrate 12) while forming the desired device application. In re Woodruff, 16 USPQ2d 1935, 1937 (Fed. Cir. 1990). 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).
But Laroche, Romano, Hsiung, KAMATA, Odnoblyudov & SMITH above still do not explicitly teach,
……for generating an abrupt end point detection signal,
However, the above claim limitation “for generating an abrupt end point detection signal” does not distinguish the present invention over the prior art of LaRoche in view of Romano in view of Hsiung in view of KAMATA in view of Odnoblyudov in view of SMITH, who teaches the structure as claimed. Moreover, it has been held that a recitation with respect to the manner in which a claimed apparatus is intended to be employed does not differentiate the claimed apparatus from a prior art apparatus satisfying the claimed structural limitations. Ex parte Masham, 2 USPQ 2d 1647 (1987).
Regarding claim 14, Laroche, Romano, Hsiung, KAMATA, Odnoblyudov & SMITH teach the vertical semiconductor component of claim 13 and further teaches, wherein the further chemical element is carbon (further chemical element is carbon as per claim 13 rejection above).
Regarding claim 15, Laroche, Romano, Hsiung, KAMATA, Odnoblyudov & SMITH teach the vertical semiconductor component of claim 13 and further teaches, wherein the third background concentration includes a range between 1E18 cm-3 and 1E19 cm-3 (during routine optimization and experimentation it would have been obvious to hit the range between 1E18 cm-3 and 1E19 cm-3).
Conclusion
Any inquiry concerning this communication or earlier communications from the examiner should be directed to KHATIB A RAHMAN whose telephone number is (571)270-0494. The examiner can normally be reached on MON-FRI 8:00 am- 5:00 pm (Arizona).
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/K.A.R/Examiner, Art Unit 2813
/STEVEN B GAUTHIER/Supervisory Patent Examiner, Art Unit 2813