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 .
Claim Objections
Claims 9 and 12 are objected to because of the following informality: “the substrate” should be “the support substrate” for consistency with the antecedent basis. Appropriate correction is required.
Claim Rejections - 35 USC § 112
Claims 4-6 are 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.
Regarding claims 4 and 6, the term “arrow f200” in renders the claims indefinite because the term lacks clear meaning and is not defined by the claim. The specification does not provide a standard for determining what physical quantity f200 represents, how it is measured, the direction of measurement, or the reference points used. Therefore, one of ordinary skill in the art would not be reasonably apprised of the scope of the invention. In particular, the limitation “f200 ≥ 0.05*(D200−D360)” in claim 4 (and similarly in claim 6) is indefinite because it is unclear what parameter is being compared or how it is determined.
Claim 5 is rejected 35 U.S.C. 112(b) or 35 U.S.C. 112 (pre-AIA ), second paragraph, as being indefinite for the same reason set forth with respect to claim 4, from which it depends.
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.
This application currently names joint inventors. In considering patentability of the claims the examiner presumes that the subject matter of the various claims was commonly owned as of the effective filing date of the claimed invention(s) absent any evidence to the contrary. Applicant is advised of the obligation under 37 CFR 1.56 to point out the inventor and effective filing dates of each claim that was not commonly owned as of the effective filing date of the later invention in order for the examiner to consider the applicability of 35 U.S.C. 102(b)(2)(C) for any potential 35 U.S.C. 102(a)(2) prior art against the later invention.
Claims 1, 2, 3, 7, 12, 16, 18, and 20 are rejected under 35 U.S.C. 103 as being unpatentable over Chen et al. (US 2015/0102465 A1) in view of Li et al. (Y. Li et al., “Three-Dimensional Anisotropic Microlaser from GaN-Based Self-Bent-up Microdisk,” ACS Photonics 5(11) (2018)).
Regarding claim 1, Chen teaches supplying a stack comprising a support substrate, a sacrificial layer, and a layer of interest (paragraphs [0009], [0042], [0043]). Chen teaches a silicon substrate 102 corresponding to the claimed support substrate, a Ge buffer layer 104 corresponding to the sacrificial layer, and device layers formed over the sacrificial layer corresponding to the claimed layer of interest. Chen further teaches the layer of interest is patterned to define a structure having a sidewall (paragraph [0025], [0047]-[0050]), corresponding to the claimed a layer of interest delimited in all directions of the horizontal plane by a sidewall. Chen further teaches selectively removing a portion of the sacrificial layer using an isotropic etch while retaining a remaining portion beneath the structure (paragraphs [0047] – [0053], [0061]), corresponding to the claimed removing a removal portion of the sacrificial layer while retaining a remaining portion. Chen further teaches patterning the layer of interest into a microdisk structure having sidewalls and selectively removing a removal portion of the sacrificial layer using an isotropic fluorine-based etch while retaining a remaining central support portion beneath the structure (paragraphs [0025], [0047]–[0053], [0061]). Chen also teaches that structuring of the layer of interest occurs prior to removal of the sacrificial layer (paragraphs [0025], [0047]–[0050]). Chen’s patterned microdisk structure defines a layer of interest delimited in all directions of the horizontal plane by a sidewall. Due to the isotropic nature of the etch, one of ordinary skill in the art would have understood that removal proceeds laterally inward from the perimeter of the structure, such that the removed region forms a closed contour in the horizontal plane aligned with the sidewall of the layer of interest.
Chen does not teach a tensor layer delimited in all directions of the horizontal plane by a sidewall and having a residual stress configured to cause bending of the entire layer of interest in a single direction of bending during the step of removing the removal portion, nor does Chen teach a distinct stress-inducing layer configured to produce controlled deformation, nor that residual stress is intentionally engineered to cause bending of the entire layer of interest during the removal step, nor that such bending occurs in a defined single direction.
Li teaches that a strained multilayer structure formed over a sacrificial layer wherein the strain within the multilayer acts as a stress-inducing layer that causes bending upon release (page 4260, 1st paragraph). This strained layer corresponds to the claimed tensor layer having a residual stress configured to cause bending of the layer of interest. Li further teaches that upon release of the strained multilayer structure, the structure bends away from the substrate in a single direction of bending (Fig. 1), thereby causing the sidewalls of the structure to move away from the substrate during the removal step.
It would have been obvious to one of ordinary skill in the art at the time of the invention to modify Chen to include a strained layer taught by Li as a tensor layer, such that upon removal of the sacrificial layer the structure bends due to residual stress, yielding the predictable result of forming a bent three-dimensional structure. See MPEP § 2143(I)(B).
Regarding claim 2, Chen teaches the method of claim 1, including forming a patterned layer of interest having a substantially circular shape in projection in the horizontal plane, for example a microdisk structure (paragraphs [0041], [0043], and [0061]). Chen therefore teaches a sidewall of the layer of interest having a substantially circular shape.
Chen does not teach that both the sidewall of the layer of interest and the sidewall of the tensor layer each have a substantially elliptical or substantially circular shape in projection in the horizontal plane, as recited, because Chen does not explicitly disclose a tensor layer.
Li teaches forming multilayer structures that are patterned into microdisk geometries prior to release, where the multilayer structure defines a circular precursor structure that undergoes bending upon release (page 4260, 1st paragraph; page 4262, Method section). Such multilayer structures include multiple layers that share substantially circular sidewalls corresponding to the patterned geometry.
The modification of Chen in view of Li to include the strained tensor layer results in both the layer of interest and the tensor layer being patterned with substantially circular sidewalls, as shown in Chen (Figs. 3H, 4, 6A, 8A) and Li (page 4260, Figs. 1(a)-(f)).
Regarding claim 3, Chen teaches the method of claim 1, including forming a substantially circular microdisk structure and selectively removing the sacrificial layer using an isotropic undercut etching process while retaining a remaining portion beneath the structure (paragraphs [0047]–[0053], [0061]). Chen further teaches that the remaining portion of the sacrificial layer has a substantially circular shape in projection in the horizontal plane, as shown in Figs. 3H, 4, 6A-6B, and 8A- 8B.
Regarding claim 7, Chen teaches the method of claim 1, including forming stacked layers comprising a substrate, a sacrificial layer, and device layers, and patterning the device layers using lithographic and etching processes to define sidewalls (paragraphs [0025], [0047]–[0052]). Chen teaches that the patterned microdisk structure is defined by etching through the stacked layers using common lithographic patterning and etching steps, thereby producing aligned features in the vertical direction (paragraphs [0047]-[0052).
Chen does not teach that, at least during the removal step, the sidewall of the tensor layer is in the extension of the sidewall of the layer of interest in the vertical direction, as recited, particularly because Chen does not explicitly disclose a tensor layer as a distinct element.
Li teaches forming multilayer structures that are patterned into microdisk geometries prior to release, where the layers are formed and patterned together such that corresponding layers share common lateral boundaries (page 4262, Method section). This indicates that multiple layers in the stack are patterned simultaneously using a common mask, resulting in aligned sidewalls.
It would have been obvious to one of ordinary skill in the art to form the tensor layer and the layer of interest such that their sidewalls are aligned in the vertical direction because such alignment results from standard lithographic patterning and etching of stacked layers using a common mask. One of ordinary skill in the art would have recognized that this approach ensures structural alignment and fabrication simplicity, yielding predictable results, in accordance with MPEP § 2143(I)(B).
Regarding claim 12, Chen in view of Li as applied to claim 1 above further teaches the limitations of claim 12, wherein the bending of the layer of interest moves the sidewall away from the substrate, as shown by Li’s disclosure of upward bending of the released structure away from the substrate (Fig. 1).
Regarding claim 16, Chen teaches the method of claim 1, including patterning structures such as microdisks using lithographic techniques, where multiple structures may be formed across a substrate in a planar arrangement (paragraphs [0041], [0043]).
Chen teaches forming a plurality of structures across a substrate, as shown in Figs. 6A-6B and 8A, corresponding to a plurality of layers of interest contained in the same plane prior to removal of the sacrificial layer.
Regarding claim 18, Chen teaches the method of claim 1, including structuring the layer of interest prior to removal of the sacrificial layer. Specifically, Chen teaches patterning the layer of interest into a microdisk structure using lithographic and etching techniques before selectively removing the sacrificial layer to release the structure (paragraphs [0025], [0047]–[0050]). Thus, Chen teaches performing a structuring step prior to the step of removing the removable portion of the sacrificial layer, as recited.
Regarding claim 20, Chen teaches the method of claim 1, wherein the structuring step further comprises the implementation of optical lithography. Specifically, Chen teaches that microdisks were fabricated using optical lithography (paragraph [0047]) and that a photoresist layer was exposed under UV radiation using an ASML PAS 5500/60 stepper with a microdisk mask (paragraph [0048]). Thus, Chen teaches that the structuring step further comprises the implementation of optical lithography, as recited.
Claim 8 is rejected under 35 U.S.C. 103 as being unpatentable over Chen in view of Li as applied to claim 1 above and further in view of Mei et al. (US 6,844,214 B1).
Regarding claim 8, Chen teaches the method of claim 1, including supplying a stack comprising a support substrate, a sacrificial layer, and a layer of interest, and removing a removal portion of the sacrificial layer to release the layer of interest and form a three-dimensional structure (paragraph [0009]). Chen further teaches selectively undercutting the Ge buffer 104 using an isotropic dry etch while retaining a support post beneath the released structure (paragraph [0053]).
Chen in view of Li as applied to claim 1 above does not teach removing the tensor layer after removal portion of the sacrificial layer.
Mei teaches a multilayer structure including multiple layers having different residual stresses that form a stress gradient, wherein removal of a sacrificial layer causes the structure to curl due to the stress gradient (col. 8, lines 6–19). Mei further teaches that individual layers within such multilayer structures may be selectively removed using etchants that are selective with respect to other layers (col. 6, line 67 – col. 7, line 13), thereby demonstrating that layers in a stress-engineered multilayer stack may be removed independently after formation.
It would have been obvious to one of ordinary skill in the art at the time of the invention to further remove the tensor layer after release because Mei teaches that individual layers in a multilayer structure may be selectively removed using etchants selective to other layers. One of ordinary skill in the art would have recognized that such selective removal allows modification of the structural and mechanical properties of the released structure, yielding predictable results. See MPEP § 2143(I)(B).
Claims 9, 10, and 11 are rejected under 35 U.S.C. 103 as being unpatentable over Chen in view of Li, as applied to claim 1 above, and further in view of Garg et al. (V. Garg et al., “Controlled Manipulation and Multiscale Modeling of Suspended Silicon Nanostructures under Site-Specific Ion Irradiation,” ACS Applied Materials & Interfaces 12(5) (2020)).
Regarding claims 9, 10, and 11, Chen teaches the method of claim 1, including supplying a multilayer stack over a sacrificial layer and selectively removing a portion of the sacrificial layer to release the structure (paragraphs [0009], [0053]). Chen further teaches that the released structure may exhibit deformation due to internal stress, such as waviness after undercutting (paragraph [0059]).
Chen does not teach that bending of the layer of interest during the removal step brings the sidewall closer to the support substrate, nor does Chen teach controlled directional bending of the released structure toward the support substrate.
Li teaches that a strained multilayer structure bends upon release due to residual stress, where deformation occurs as a result of stress within the layers (page 4260, 1st paragraph).
Li does not teach selecting or engineering the stress state so that the bending brings the sidewall closer to the support substrate in the context of Chen’s structure.
Garg teaches that deformation direction in suspended structures can be controlled through engineering of localized tensile and compressive stress states, including downward deformation toward a substrate depending on the stress distribution (Results and Discussion, “Site-Specific Ion Irradiation-Induced Bidirectional Bending”; Fig. 1 description).
It would have been obvious to one of ordinary skill in the art at the time of the invention to configure the structure such that bending occurs toward the substrate because Li teaches that bending occurs due to residual stress, and Garg teaches that deformation direction can be controlled, including bending toward a substrate. One of ordinary skill in the art would have further recognized that bringing the structure into proximity with the substrate is a predictable result of such controlled deformation, and that contact/bonding between surfaces may occur a natural consequence of the bending process. See MPEP § 2143(I)(B).
Claim 13 is rejected under 35 U.S.C. 103 as being unpatentable over Chen in view of Li as applied to claim 1 above, and further in view of Besling et al. (US 2016/0023893 A1).
Chen teaches the method of claim 1, including forming multilayer semiconductor structures over a sacrificial layer and releasing the structure by selective removal (paragraphs [0009], [0053]). Chen further teaches that strain is present in the structure and may affect deformation behavior after release (paragraph [0059]).
Modified Chen does not teach that the residual stress σ100 such that |σ100| > 500 MPa, as recited.
Besling teaches that thin film layers used in semiconductor structures may have tensile stresses greater than 600 MPa, and in some embodiments on the order of 1000–1600 MPa (paragraph [0062]).
It would have been obvious to one of ordinary skill in the art to select a residual stress magnitude greater than 500 MPa because residual stress is a result-effective variable that directly influences deformation behavior, and Besling teaches that thin film layers may exhibit tensile stresses greater than 600 MPa. Selecting a stress value within a known range to achieve a desired deformation therefore represents routine optimization of a result-effective variable, yielding predictable results, in accordance with MPEP § 2144.05(I).
Claim 14 is rejected under 35 U.S.C. 103 as being unpatentable over Chen in view of Li as applied to claim 1 above, and further in view of Zhong et al. (US 2012/0194496 A1).
Chen teaches the method of claim 1, including forming device layers over a sacrificial layer prior to release, where stress is present in the structure (paragraphs [0009], [0059]).
Modified Chen does not teach that, before the removal step, the layer of interest has a residual stress σ200 such that |σ200| ≤ 100 MPa, as recited.
Zhong teaches that stress values of individual layers are controlled during fabrication of multilayer structures prior to actuation or deformation, including stress ranges such as −50 MPa to +50 MPa (paragraph [0095]), which fall within the claimed range of |σ200| ≤ 100 MPa.
It would have been obvious to one of ordinary skill in the art to select a relatively low residual stress for the layer of interest prior to removal because Li and Zhong teach that differential stress between layers controls bending behavior, and Zhong teaches stress values within low-magnitude ranges including values within ±100 MPa. Selecting a stress value within a known range to achieve a desired deformation profile represents routine optimization of a result-effective variable, yielding predictable results, in accordance with MPEP § 2144.05(I).
Claims 15 and 17 are rejected under 35 U.S.C. 103 as being unpatentable over Chen in view of Li as applied to claims 1 and 16 above, and further in view of Duqi et al. (US 2024/0061236 A1).
Regarding claims 15 and 17, Chen teaches forming a released structure that bends due to residual stress after removal of a sacrificial layer, and further teaches forming a plurality of such structures in a common plane across a substrate (Figs. 6A-6B, and 8A).
Modified Chen does not teach that each layer of interest forms a lens after release.
Duqi teaches forming curved microstructures that function as optical lenses, including embodiments where a plurality of microstructures each form a corresponding micro-lens (claims 14 and 17).
It would have been obvious to one of ordinary skill in the art at the time of the invention to configure the curved structures of modified Chen to provide an optical function, because Duqi teaches that curved microstructures formed from thin films may function as optical lenses, including in array configurations. Applying a known optical function to one or more curved structures represents a predictable use of prior art elements according to their established functions in accordance with MPEP § 2143(I)(B).
Claim 19 is rejected under 35 U.S.C. 103 as being unpatentable over Chen in view of Li as applied to claim 1 above, and further in view of U’Ren (US 2008/0094686 A1).
Chen teaches the method of claim 1, including forming a multilayer structure over a sacrificial layer and selectively removing the sacrificial layer to release the structure (paragraphs [0009], [0042], [0043], [0053]). Chen further teaches patterning the structure prior to release using lithographic and etching techniques (paragraphs [0025], [0047]–[0050]).
Modified Chen does not teach that the stack further comprises a secondary layer of interest above the tensor layer, wherein the removal portion is also carried out selectively relative to the secondary layer of interest, and wherein the method further comprises, prior to the step of removing the removal portion, a step of structuring the secondary layer of interest, as recited.
U’Ren teaches forming a second sacrificial layer 850 over the movable conductor 840 and spacer 844 (paragraph [0070]), and further teaches forming a deformable layer 870 over the second sacrificial layer 850 (paragraph [0079]), wherein the deformed layer corresponds to the claimed secondary layer of interest. U’Ren also teaches that the deformable layer 870 may be patterned and etched prior to removal of the sacrificial layers (paragraph [0079]). In addition, U’Ren teaches that the support post material is chosen such that a selective etch can remove the sacrificial materials of sacrificial layers 830 and 850 selectively relative to the post material and electrode material (paragraph [0078]). U’Ren further teaches removal of the sacrificial layers after formation of the overlying structure (paragraph [0081]).
It would have been obvious to one of ordinary skill in the art at the time of the invention to include and structure an additional layer above the stress-producing layer prior to sacrificial-layer removal because U’Ren teaches multilayer structures in which an overlying deformable layer is formed, patterned, and retained while sacrificial layers are selectively removed. Incorporating such multilayer fabrication and selective release techniques into Chen represents the application of a known technique to a known structure to achieve predictable results, in accordance with MPEP § 2143(I)(B).
Conclusion
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/JONATHAN L CARTER/Examiner, Art Unit 1713
/JOSHUA L ALLEN/Supervisory Patent Examiner, Art Unit 1713
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