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 without traverse of claims 1-19 in the reply filed on 8/7/26 is acknowledged.
Claim Rejections - 35 USC § 112
Claim 18 is rejected under 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for failing to particularly point out and distinctly claim the subject matter which the inventor or a joint inventor (or for applications subject to pre-AIA 35 U.S.C. 112, the applicant), regards as the invention.
The limitation of “wherein the method does not cause any other substantially damage to the substrate” is vague and indefinite. It is not clear what the term “other damage” encompasses and it is not clear how the method is not “substantially” damaging the substrate.
Claim 13 recites the limitation "wherein the method further comprises rotating the substrate during the methods". There is insufficient antecedent basis for this limitation in the claim.
Claim 13 is vague and indefinite because it is not clear which steps in claim 1 that the substrate rotates or it rotates throughout the process of claim 1.
Claim 19 recites the limitation "the number of cycles". There is insufficient antecedent basis for this limitation in the 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 (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.
Claim(s) 1-10, 14, 15, 17-19 is/are rejected under 35 U.S.C. 103 as being unpatentable over Patrick et al. (The competing oxide and sub-oxide formation in metal-oxide molecular beam epitaxy).
With respect to claims 1-6, 9 Patrick teaches a study of growing oxides on semiconductor substrate such as GaN or group III-V substrate includes providing oxygen-rich conditions such as oxygen or ozone to grow oxides (page 2). Unlike claimed invention, Patrick doesn’t explicitly teach etching the oxidized layer on the group III-V substrate with an etchant comprising at least one of group III elements which react with the oxide to form a suboxide, which desorbs from the surface. However, he teaches conditions that promote etching of the oxidized layer with an etchant comprising fluxes of atomic metals (e.g. Ga, In an Sn) or the group III element as he describes “during the metal-rich growth of some oxides, however, excess metal can also desorb as volatile sub-oxide, consuming part of the provided oxygen flux thereby reducing the growth-rate with increasing metal flux”; “if the metal flux is provided in the absence of oxygen, even an etching scenario is conceivable, as schematically shown in Fig. 1(c) for Ga2O3. Here, the supplied gallium atoms react with the surface of the already grown oxide film to the volatile sub-oxide, which desorbs subsequently”
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., and “Etching of different oxides by a Ga metal flux, as indicated in Fig. 1(c), has been qualitatively observed and exploited for the removal of surface oxides from Si,20 SiC,21 and GaAs22 substrates” (page 3, 4) and “Fig. 4 also shows that the proportionally increase of the oxide etch-rates are increasing with the metal flux in absence of oxygen flux. This implies that the metal impinging onto the already grown oxide layer decomposes the film, resulting in the reduction of the epilayer and decrease of its thickness” (page 8). Therefore, it would have been obvious for one skilled in the art before the effective filing date of the invention to provide a method that includes an etching of the oxide layer on a group III-V because Patrick shows that these steps have been successfully in growing and etching oxides on semiconductor substrate of group III-V and he also teaches growing and subsequent etching of the oxides in page 5 “figure 2 presents the variation of the laser intensity during the deposition and subsequent etching of the oxides. Two oscillations are observed, one for growing and one for etching afterwards” to form semiconductor devices such as transparent electronics, transistors, and sensors (page 2) with expected results.
With respect to claims 7, 15 Patrick gives examples of semiconductor substrate of GaN and the etchant of metal flux includes Ga (page 2, fig. 1).
With respect to claim 10, fig. 1 and 2 show atomic flux of the etchant including Ga.
With respect to claim 17, it is expected that the method does not cause any other substantially damage to the substrate as the same material is being etched with the same chemicals.
With respect to claim 18, even though Patrick is silent about repeating the method to etch another layer. However, it would have been obvious to one skilled in the art before the effective filing date of the invention to repeat it as necessary depending on what materials present on the semiconductor devices during the process to etch another material so that a desired structure for a semiconductor device can be formed.
With respect to claim 19, it would be obvious that repeating the steps from Patrick’s process would remove more material from the substrate. Therefore, selecting a number of cycles of Patrick’s process to remove a desired thickness of the substrate would have been obvious and within the knowledge of one skilled in the art depending on a desired device is being manufactured.
With respect to claim 14, fig. 3 shows etching time with Tsub is at 550 degrees C.
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With respect to claim 8, the oxidizing step by Patrick would comprise an oxidized monolayer since it is the same oxidizing method on the same group III-V materials.
Claim(s) 11, 12 is/are rejected under 35 U.S.C. 103 as being unpatentable over Patrick as applied to claim 1 above, and further in view of Ma et al. (CN 111710650A).
With respect to claim 11 and 12, Patrick doesn’t teach a substrate comprising an etch stop layer that is not susceptible to etching by the etchant and using a pattern mask for the oxidizing step wherein the uncovered portion of the substrate is oxidized. Ma teaches of forming a GaN device comprising buffer 102 of AlGaN layer and a barrier 104 of AlN layer (page 6), which provides claimed an etch stop layer, and a mask pattern 109 for oxidizing exposed portion of GaN layer 105 (page 5, 7; fig. 7, 8)
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. It would have been obvious for one skilled in the art before the effective filing date of the invention to provide oxidizing mask and extra layers including AlGaN and AlN layers or claimed etch stop layer in light of Ma because Ma shows that these steps are necessary in the process of making circuit design of GaN device (page 1, 2).
Claim(s) 13 is/are rejected under 35 U.S.C. 103 as being unpatentable over Patrick as applied to claim 1 above, and further in view of Atanackovic (WO 2023084283A1).
With respect to claim 13, the limitation of rotating the substrate during the methods is interpreted as rotating in any steps during the process. Patrick doesn’t teach rotating the substrate during the steps of processing the substrate. Atanackovic teaches to rotate the substrate as the activated epitaxial growth surface is exposed to atomic beam including oxygen atomic beam during the oxidizing process (page 22, 23: para 487-495). It would have been obvious for one skilled in the art before the effective filing date of the invention to rotate the substrate during the oxidizing step because Atanackovic teaches that rotating the substrate would facilitate in accumulation an uniform amount of atomic beam intersecting the substrate surface for a given amount of deposition time (page 22, 23: para 495).
Allowable Subject Matter
Claim 16 is 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. With respect to claim 16, Patrick even though teaches processing materials including such as GaN, GaAs and forming oxides including Ga2O3, Al2O3; however, he doesn’t teach the etchant comprises Al for the process of AlN substrate.
Any inquiry concerning this communication or earlier communications from the examiner should be directed to DUY VU NGUYEN DEO whose telephone number is (571)272-1462. The examiner can normally be reached 9-5 M-F.
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/DUY VU N DEO/Primary Examiner, Art Unit 1713
9/11/2026
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