DETAILED ACTION
This is the Office action based on the 17446723 application filed September 2, 2021, and in response to applicant’s argument/remark filed on October 21, 2025. Claims 1-3 and 5-18 are currently pending and have been considered below. Applicant’s cancellation of claim 4 acknowledged.
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 .
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.
Claim Interpretations
Claim 1 recites “a first plasma comprising chlorine”. According to Merriam-Webster Dictionary, the word “chlorine” means “a halogen element that is isolated as a heavy greenish yellow gas of pungent odor and is used especially as a bleach, oxidizing agent, and disinfectant in water purification —symbol Cl”. Therefore, for the purpose of examining a plasma including chlorine will be interpreted as a plasma containing element Cl. Similarly, the term “a second plasma comprising helium or hydrogen” will be interpreted as a plasma containing element He or H.
Drawings
The drawings are objected to under 37 CFR 1.83(a) because Fig. 1 fails show any content in the boxes, as referred to in the specification. Any structural detail that is essential for a proper understanding of the disclosed invention should be shown in the drawing. MPEP § 608.02(d). 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 § 112
The following is a quotation of the first paragraph of 35 U.S.C. 112(a):(a) IN GENERAL.—The specification shall contain a written description of the invention, and of the manner and process of making and using it, in such full, clear, concise, and exact terms as to enable any person skilled in the art to which it pertains, or with which it is most nearly connected, to make and use the same, and shall set forth the best mode contemplated by the inventor or joint inventor of carrying out the invention.
Claim 1 rejected under 35 U.S.C. 112(a) as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor(s), at the time the application was filed, had possession of the claimed invention. Examiner is unable to find support for the limitation “removing a first part of a thickness of the at least one portion of the III-N material layer using a first plasma comprising chlorine by a single cycle of reactive ion etching” (emphasis added) in the specification. Although the specification discloses “(a) first part of the thickness of the portion of the III-N material layer is first etched during a first etching 102. This first etching 102 is implemented by using a first plasma including chlorine, with the addition of for example BCl3 or SiCl4. This first etching 102 is implemented for a period of time sufficient to etch a large part of the thickness of the portion of the III-N material layer to be etched, for example between about 80% and 90% of that thickness” in paragraphs [0049-0050] and “(w)hen the steps of the method are implemented at a temperature of 40° C., each cycle of implementation of steps 104-110 may etch a material thickness of about 1.4 nm” in paragraph [0076], it fails to define the term “single cycle of reactive ion etching” nor disclose any details about a cycle comprising step 102. It is also noted that the term “single cycle of reactive ion etching” is indefinite, as explained below. See MPEP, 2173.05i. For the purpose of examining it will be assumed that the claimed cycle of reactive ion etching may comprise a plurality of etching steps.
Claim 1 rejected under 35 U.S.C. 112(a) as failing to comply with the written description requirement. The claim(s) contains subject matter which was not described in the specification in such a way as to reasonably convey to one skilled in the relevant art that the inventor(s), at the time the application was filed, had possession of the claimed invention. Examiner is unable to find support for the limitation “wherein a) is executed such that b), c), and d) are implemented one or more times only to etch the at least one part of the remaining thickness of the at least one portion of the III-N material layer” (emphasis added). Although the specification discloses “After implementing this first etching 102, exposing 104 at least one part of the remaining thickness of the portion of the III-N material layer to a second plasma including helium or hydrogen is implemented” ([0051]), “A step 106 of chlorinating the part of the remaining thickness of the portion of the III-N material layer modified by the previous step 104 is then implemented, transforming this part of the remaining thickness of the portion of the III-N material layer into a chlorinated material layer.” ([0058]), and “A second etching 108 of the chlorinated material layer obtained at the end of the previous chlorination step 106 is then implemented by using a third plasma including argon. This second etching 108 enables the entire thickness of the chlorinated material layer to be etched.” ([0066]), the specification does not teach steps 104, 106 and 108 are implemented only to etch the at least one part of the remaining thickness of the at least one portion of the III-N material layer, and nothing else. For the purpose of examining it will be assumed that the phrase “only to etch” is an intention, and may or may not occur.
Claims 2-3 and 5-18 rejected under 35 U.S.C. 112(a) because they are directly or indirectly dependent on claim 1.
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.
Claim 1 rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention. The term “a single cycle of reactive ion etching” in the limitation “removing a first part of a thickness of the at least one portion of the III-N material layer using a first plasma comprising chlorine by a single cycle of reactive ion etching” (emphasis added) is not clear. The specification fails to define this term, and one of skills in the art would not be clear what steps that the single cycle of reactive ion etching would comprises, such as how it is different from a single step of reactive ion etching or what step(s) the single cycle of reactive ion etching comprises in addition to a reactive ion etching step. For the purpose of examining it will be assumed that the claimed cycle of reactive ion etching may comprise a plurality of etching steps.
Claim 18 rejected under 35 U.S.C. 112(b) as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor regards as the invention. Claim 21 recites “stabilizing the helium or hydrogen, a pressure and a temperature between b) and c)” is not clear. While stabilizing a pressure and temperature is well known in the art, one of skill in the art would not be clear what is to be stabilized in the phrase “stabilizing the helium or hydrogen”. For the purpose of examining it will be assumed that the pressure of the helium or hydrogen in the process chamber is to be stabilized.
Claims 2-3 and 5-18 rejected under 35 U.S.C. 112(b) because they are directly or indirectly dependent on claims 1.
Claim Rejections - 35 USC § 102/35 USC § 103
The following is a quotation of 35 U.S.C. 102:
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..
The following is a quotation of 35 U.S.C. 103:
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 of this title, 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 set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied 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 1-3, 5-14 and 16-18 rejected under 35 U.S.C. 102(a)(1) and 35 U.S.C. 102(a)(2) as anticipated by or, in the alternative, under 35 U.S.C. 103 as obvious over Yang et al. (U.S. PGPub. No. 20160358782), hereinafter “Yang”.
--Claims 1, 2, 9, 10, 12: Yang teaches a method for etching a III-V layer, such as a GaN layer that is a part of a GaN/AlGaN structure, (abstract, Fig. 1A, 1E; [0024]) comprisingi) providing a substrate comprising a GaN layer in a process chamber in a reactor ([0026], Fig. 2);ii) exposing the GaN layer to a plasma comprising a “Cl-containing etching gas” ([0027]) and a carrier gas comprising Ar, N2 or He ([0026-0029], Step 104 in Fig. 1A) to form a modified GaN layer, wherein the GaN layer may be chlorinated ([0037]);iii) optionally purging the process chamber by using Ar, N2 or He ([0031]).iv) exposing the modified GaN layer to a plasma comprising Ar, N2 or He to remove the modified GaN layer ([0031-0032, 0034-0035], Step 106 in Fig. 1A);v) repeating steps ii)-iv) a plurality of cycles ([0036], Fig. 1A). Yang further discloses that in step ii) the plasma comprising the Cl-containing etching gas and the carrier gas can be generated directly in the process chamber by supplying 50-2000 W capacitively or inductively ([0030]). Since Yang describes step ii) as “(d)uring operation 104, a carrier gas may be optionally flowed, while a Cl-containing etching gas is flowed to the chamber. Examples of carrier gases include nitrogen (N2), argon (Ar), neon (Ne), helium (He), and combinations thereof” ([0027], (emphasis added), at least a portion of the GaN layer is etched during step i). This is further evidenced by Chen et al. (U.S. PGPub. No. 20230402565), hereinafter “Chen” or Zhao et al. (U.S. PGPub. No. 20210104603), hereinafter “Zhao”. Chen teaches that GaN may be etched by exposing to a plasma comprising chlorine ([0038-0040]), and Zhao teaches that GaN can be etched by using a chlorine-based ICP plasma at 200-600W ([0025]). It is noted that, although Yang discloses that “The Cl-only etch resulted in no GaN etch (100 cycles)” ([0065]), Yang also discloses that the “Cl-containing etching gas” may comprises Ar and/or He carrier gas ([0027-0028]). It is noted that the Ar and He ions would etch the chlorinated layer at the surface, as taught by Applicant and as shown in step iv). Yang further teaches that “(a)n inductively coupled plasma may be set at a plasma between about 50 W and about 2000 W. While a substrate bias may be applied, more typically no bias is applied during operation 104 to avoid sputtering”. Thus, while typically no bias is applied during operation 104, a bias may be applied that would induce some sputtering of at least a portion, such as a portion of the top monolayer of atoms, of the GaN layer, during routine experimentations. Thus, the method may be considered to comprise repeating steps a)-d) below:a) exposing the GaN layer to a plasma comprising a Cl-containing etching gas, the Cl-containing etching gas etches a portion of the GaN layer and modifies a portion of the GaN layerb) exposing the modified GaN layer to a plasma comprising He to remove the modified GaN layer c) exposing the remaining of the GaN layer to a plasma comprising a Cl-containing etching gas, the Cl-containing etching gas modifies a portion of the GaN layerd) exposing the modified GaN layer to a plasma comprising Ar to remove the modified GaN layer It is noted that in step b) since the remaining GaN layer is also exposed to the plasma comprising He, at least a portion of the surface of the remaining GaN layer would be damaged, and at least a part of this portion would be chlorinated in step c). Thussteps a)-d) are equivalent to step a)-d) recited in claim 1. Yang further teaches that “(p)erforming operations 104 and 106 may, in some embodiments, constitute performing atomic layer etch once. If the III-V material is not sufficiently etched, operations 104 and 106 may be repeated. In various embodiments, the modification and removal operations may be repeated in cycles, such as about 1 to about 30 cycles, or about 1 to about 20 cycles. Any suitable number of ALE cycles may be included to etch a desired amount of film“ ([0036]) and “a cycle may only partially etch about 0.1 nm to about 50 nm of material, or between about 0.1 nm and about 5 nm of material, or between about 0.2 nm and about 50 nm of material, or between about 0.2 nm and about 5 nm of material” ([0038]). For example, considering a method of etching that repeats operations 104/106 20 times to completely etch away a GaN layer, each times removes 5 nm of the GaN material. After 18 repetitions a remaining thickness of the GaN layer would be 10 nm. The first 18 repetitions may be considered the claimed step (a), and the last 2 repetitions may be considered the claimed steps (b), (c) and (d) repeated twice. Alternately, although Yang does not disclose the Cl-containing etching gas would etch the GaN layer or the plasma comprising He would damage the GaN layer, it would have been obvious to one of ordinary skill in the art at the effective filing date of the invention, in routine experimentations, to perform the method so that such etching and damaging occur, as taught by Applicant. According to MPEP 2112 “[T]he discovery of a previously unappreciated property of a prior art composition, or of a scientific explanation for the prior art’s functioning, does not render the old composition patentably new to the discoverer.”, Atlas Powder Co. v. Ireco Inc., 190 F.3d 1342, 1347, 51 USPQ2d 1943, 1947 (Fed. Cir. 1999). Thus the claiming of a new use, new function or unknown property which is inherently present in the prior art does not necessarily make the claim patentable. In re Best, 562 F.2d 1252, 1254, 195 USPQ 430, 433 (CCPA 1977)”. It is noted that the first cycle would remove a portion of the GaN layer, and the subsequent cycle would damage at least a part of the remaining thickness, and that Yang does not discloses the etching etches any other material besides the GaN layer.--Claims 12, 16, 17: In the example described above, it is noted that the first 18 repetitions that is considered the claimed step (a) removes 90% of the thickness of the GaN layer.--Claim 3: Yang further teaches that step iv) may comprise applying a bias voltage of 20-120 V ([0003-0005]).--Claim 5: Yang further teaches that the chlorine-containing etchant may comprise Cl2 or BCl3 ([0026]). --Claim 6: Yang further teaches that the reactor may be an ICP etching reactor ([0045]). --Claim 7: Yang further teaches that the bias voltage may be applied to the substrate, and the bias voltage may be pulsed ([0039, 0042]). Therefore, it would have been obvious to one of ordinary skill in the art at the effective filing date of the invention, in routine experimentations, to perform the exposing the modified GaN layer to a plasma comprising Ar and He by using a pulsed bias voltage. It is noted that since the bias voltage also affects the intensity of the plasma, the plasma would also be pulsed.--Claim 11: Yang further discloses that the etching of the GaN layer exposes a portion of the AlGaN for a contact area (Fig. 1E). --Claim 13: Although Yang is silent about the helium creating defects in the GaN layer, such defect creating would be inherent since the etching taught by Yang is the same as Applicant’s. --Claims 8, 14: Yang further teaches that the process chamber comprises a system controller that controls process parameters, such as flow rates and duration of steps, power, chamber pressure, etc. ([0053-0057]). Therefore, the gas flow rate, duration of step, RF power or chamber pressure are result-effective parameters. In some embodiments, Yang discloses that the plasma may be generated by using a ICP power at 50-2000W ([0030]), and the method may be performed at 1 mTorr-100Torr ([0023]). It is noted that this is equivalent to 0.133 Pa – 13332 Pa, which overlaps the claimed pressure range. Yang further teaches that the process chamber may be one that is described in Shamma et al (U.S. PGPub. No. 20140170853). Shamma teaches that the process chamber may be used to run a ALE process comprising Cl2 flow at 10-100 sccm ([0089]) Ar at 0-10000 sccm ([0042], Table 1), He at 0-9500 sccm (Table 1). Therefore, it would have been obvious to one of ordinary skill in the art at the effective filing date of the invention, in routine experimentations, to find the optimum power, step duration, plasma flow and the pressure for step ii) and iv) as recited in claim 8 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. --Claim 14: Since Yang teaches selectively etching only the GaN layer, it would have been obvious to one of ordinary skill in the art at the effective filing date of the invention during the last repetition to perform the chlorination so that only the remaining GaN layer is chlorinated and removed in step (ii) and (iv) 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. --Claims 16, 17: It is noted that the first cycle would remove a portion of the GaN layer. Although Yang is silent about a portion of the thickness being removed, it would have been prima facie obvious to one of ordinary skill in the art prior to the effective filing date of the invention to remove 80-90% of the thickness of the removal thickness in the invention of Yang since it is well established that "[W]here 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)”. MPEP 2144.05(II)(A). --Claim 18: Yang further teaches that “(a)s described herein, in operations where materials are introduced into the chamber, in some embodiments involving atomic layer etch using a plasma, the reactor or chamber may be stabilized by introducing the chemistry into the chamber prior to processing the substrate or wafer. Stabilizing the chamber may use the same flow rates, pressure, temperatures, and other conditions as the chemistry to be used in the operation following the stabilization. In some embodiments, stabilizing the chamber may involve different parameters. In some embodiments, a carrier gas, such as N2, Ar, Ne, He, and combinations thereof, is continuously flowed during operations 104 and 106.” ([0035]). Therefore, it would have been obvious to one of ordinary skill in the art at the effective filing date of the invention to stop flowing the chlorine-containing etching gas, and stabilizing the flow of Ar, N2 or He, and pressure and temperature during the purging step prior to step iv).
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 of this title, 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 set forth in Graham v. John Deere Co., 383 U.S. 1, 148 USPQ 459 (1966), that are applied 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 15 rejected under 35 U.S.C. 103 as being unpatentable over Yang as applied to claim 1 above, and further in view of Levy et al. (U.S. PGPub. No. 20040142557), hereinafter “Levy”--Claim 15: Yang teaches the invention as above. Yang further teaches that the exposing the modified GaN layer to a plasma comprising Ar and He to remove the modified GaN layer may uses activating or sputtering gas or chemically reactive species that induces removal ([0032]). Yang fails to teach using hydrogen.Levy teaches that “well know wafer preclean strategies include direct Ar and Ar-H2 sputter etch to physically remove contaminants” ([0029])Therefore, it would have been obvious to one of ordinary skill in the art at the effective filing date of the invention, in routine experimentations, to use Ar-H2 sputter etch as an equivalent substitution for the Ar sputter etch in the invention of Yang because Levy teaches that this would advantageously physically remove contaminants
Response to Arguments
Applicant's arguments filed October 21, 2025 have been fully considered as follows:--Regarding Applicant’s argument that the specification discloses the amended feature ““removing a first part of a thickness of the at least one portion of the III-N material layer using a first plasma comprising chlorine by a single cycle of reactive ion etching”, this arguments is not persuasive. Applicant cites paragraphs [0048-0050] as the support; however, while the specification discloses “This etching method is implemented here in a single RIE type etching equipment, and advantageously ICP-RIE type. A first part of the thickness of the portion of the III-N material layer is first etched during a first etching 102. This first etching 102 is implemented by using a first plasma including chlorine, with the addition of for example BCl3 or SiCl4. This first etching 102 is implemented for a period of time sufficient to etch a large part of the thickness of the portion of the III-N material layer to be etched, for example between about 80% and 90% of that thickness. The value of the remaining thickness to be etched (after the first etching) of the portion of the III-N material layer may be between about 5 nm and 50 nm” in these paragraphs, it fails to define the term “single cycle of reactive ion etching” nor discloses that the removal is performed by using a single cycle of reactive ion etching. Please also see Claim Rejection under 35 U.S.C. 112(a) and (b) above. Therefore, the previous rejections of claim 1 under 35 U.S.C. 112(a) and (b) are maintained.--Regarding Applicant’s argument that “Yang fails to disclose or suggest "a) is executed such that b), c), and d) are implemented one or more times only to etch the at least one part of the remaining thickness of the at least one portion of the III-N material layer, wherein the at least one part of the remaining thickness of the at least one portion of the III-N material layer has a thickness of from 5 nm to 10 nm" as recited in Claim 1.”, Yang inherently discloses this feature. As the example in the Office action explains, since Yang teaches that “(p)erforming operations 104 and 106 may, in some embodiments, constitute performing atomic layer etch once. If the III-V material is not sufficiently etched, operations 104 and 106 may be repeated. In various embodiments, the modification and removal operations may be repeated in cycles, such as about 1 to about 30 cycles, or about 1 to about 20 cycles. Any suitable number of ALE cycles may be included to etch a desired amount of film“ ([0036]) and “a cycle may only partially etch about 0.1 nm to about 50 nm of material, or between about 0.1 nm and about 5 nm of material, or between about 0.2 nm and about 50 nm of material, or between about 0.2 nm and about 5 nm of material” ([0038]). For example, considering a method of etching that repeats operations 104/106 20 times to completely etch away a GaN layer, each times removes 5 nm of the GaN material. After 18 repetitions a remaining thickness of the GaN layer would be 10 nm. The first 18 repetitions may be considered the claimed step (a), and the last 2 repetitions may be considered the claimed steps (b), (c) and (d) repeated twice.
Conclusion
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 mailing date of this final action.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to THOMAS PHAM whose telephone number is (571) 270-7670 and fax number is (571) 270-8670. The examiner can normally be reached on MTWThF9to6 PST.
If attempts to reach the examiner by telephone are unsuccessful, the examiner’s supervisor, Parviz Hassanzadeh can be reached on (571) 272-1435. The fax phone number for the organization where this application or proceeding is assigned is 571-273-8300.
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/THOMAS T PHAM/Primary Examiner, Art Unit 1713