Patterned probe structures, methods for fabrication, and micro-mechanical spring systems containing the same

Abstract

A method of fabricating a plurality of patterned probes includes steps of depositing a plurality of layers on a substrate; exposing the plurality of layers including includes a silicon-containing film and a non-silicon bilayer resist, thereby forming at least one intermediary nanostructure arran 5 ged in a pattern; depositing a hard mask layer on the plurality of layers; performing a liftoff of portions of the hard mask layer, thereby forming a sample; placing the sample into a chamber; flowing etching gas including fluorine compound etching gas into the chamber; and etching portions of the sample to form the plurality of patterned probes distributed across the substrate. Each 10 patterned probe includes a sidewall profile having a first portion between an attachment to the substrate and an inflection region, and a second portion between the inflection region and a distal end, and the first portion and the second portion have different profile characteristics.

Description

[0001]2101715-001260 -1- PATTERNED PROBE STRUCTURES, FOR FABRICATION, AND MICRO- MECHANICAL SPRING SYSTEMS CONTAINING THE SAME CROSS-REFERENCE TO RELATED APPLICATIONS This application claims priority to United States Provisional Application No. 63 / 600,406, filed November 17, 2023, and to United States Provisional Application No. 63 / 601,657, filed November 21, 2023, both titled “MICRO-MECHANICAL SPRING WITH PATTERNED PROBE TIP STRUCTURE,” the contents of all of which are incorporated herein by reference in their entireties for all purposes. REFERENCE TO U.S. GOVERNMENT SUPPORT This invention was made with government support under Grant No. 2128534, awarded by the U.S. National Science Foundation. The United States has certain rights in the invention. FIELD OF THE INVENTION Aspects of the invention relate generally to nanofabrication technology. More particularly, aspects of the invention relate to method and systems for fabricating patterned probes. BACKGROUND OF THE INVENTION The advancement of nanofabrication has enabled complex technologies that utilize patterned probes or nanostructures (NSs) for subwavelength optics and nanoscale local probes. While optical devices such as waveguides and photonic crystals typically require smooth and vertical sidewalls for performance optimization and reduced sidewall scattering, many arising technologies have introduced variation of the NS morphology as an additional degree of freedom for tuning device functionality. Of significant importance are nanocones, which rely on the ability to fabricate NSs with tapered sidewalls. When patterned into arrays, subwavelength nanocones behave as a material with gradient refractive index, progressively bending incident light into the substrate onto which the nanocones are patterned. Recently, silicon (Si) and silica nanocones have attracted tremendous interest for applications in anti-reflection and anti-fogging coatings, drug-delivery systems, superhydrophobic surfaces, and surfaces for optical absorption enhancement While Si nanocone fabrication is well understood, silica nanocone formation is limited by current fabrication techniques. Silica nanocones exhibit remarkable physical 2101715-001260 -2- and optical properties that enable super-transmissivity, super- hydrophobicity, ultra-low diffuse reflectance and anti-fogging, and templates for hot electron photodetection. A majority of these investigations utilize nanosphere lithography or techniques resulting in random distribution of silica nanocones. While these methods are suitable for high-throughput manufacturing, they limit the tunability of the nanostructured surface. Further, although hybrid Si / SiO2 NSs can be fabricated by thermal oxidation of Si, the oxide growth on sidewalls alters the morphology of NSs and high temperatures place limitations on process integration. Many RIE etching processes have been developed to achieve tapered silica sidewalls by varying temperature and etching gases, but these studies employed photolithography-defined masks and applicability of these processes to the fabrication of NSs have not been explored. Furthermore, prior investigations of silica nanostructures have been fabricated using thermally grown SiO2 or fused silica wafers, thereby limiting process integration to specific substrate materials. Prior techniques to fabricate patterned probes or nanostructures, such as silicon oxide nanocones, involve complex fabrication procedures, non-deterministic placement, or poor uniformity. Therefore, there remains a desire for improvements in systems and methods for fabricating patterned probes, or apparatuses and systems having the patterned probes. Techniques that offer full control over the distribution and morphology of patterned probes facilitate construction of new solid-state sensors and optical surfaces for applications including but not limited to nanophotonics, strain engineering of two-dimensional materials, and biological sensing. Integration of fully tailorable patterned probes with micro-mechanical devices enables dynamic probing that may enhance or replace existing material characterization techniques, such as atomic force microscopy and tip-enhanced spectroscopy. SUMMARY OF THE INVENTION According to an aspect of the invention, a method of fabricating a plurality of patterned probes is provided. The method includes steps of (a) depositing a plurality of layers on a substrate; (b) exposing the plurality of layers, thereby forming at least one intermediary nanostructure arranged in a pattern; (c) depositing a hard mask layer on the plurality of layers; (d) performing a liftoff of portions of the hard mask layer, thereby forming a sample; (e) placing the sample into an inductively-coupled plasma (ICP) chamber; (f) flowing etching gas into the chamber; and (g) etching portions of the sample to form the plurality of patterned probes distributed across the substrate. In some aspects of the invention, the plurality of layers includes a silicon-containing film 2101715-001260 -3- and a non-silicon bilayer resist the silicon-containing film. In certain aspects of the invention, the etching gas includes fluorine compound etching gas. According to another aspect of the invention, a method of fabricating a plurality of patterned probes is provided. The method includes steps of (a) depositing a plurality of layers on a substrate that defines a horizontal surface; (b) exposing the plurality of layers, thereby forming a pattern of at least one intermediary nanostructure; (c) depositing a hard mask layer on the plurality of layers; (d) performing a liftoff of portions of the hard mask layer, thereby forming a sample; (e) placing the sample into an inductively-coupled plasma (ICP) chamber; (f) flowing etching gas into the chamber; and (g) etching portions of the sample to form the plurality of nanostructures on the substrate. In some aspects of the invention, the plurality of layers includes a silicon-containing film and a non-silicon bilayer resist developed on the silicon- containing film. In certain aspects of the invention, the etching gas includes fluorine compound etching gas. Each of the plurality of patterned probes includes a sidewall profile having a first portion between an attachment to the substrate and an inflection region, and a second portion between the inflection region and a distal end. The first portion and the second portion have different profile characteristics. According to yet another aspect of the invention, a method of fabricating a system having a micro-mechanical spring and a plurality of patterned probes is provided. The method includes steps of (a) fabricating the micro-mechanical spring; (b) fabricating patterned probes; (c) releasing the micro-mechanical spring. BRIEF DESCRIPTION OF THE DRAWINGS The foregoing summary and the following description will be better appreciated and understood in conjunction with the non-limiting examples illustrated in the attached drawing figures, of which: FIG. 1 depicts an exemplary method of fabricating at least one patterned probe in accordance with an embodiment of the invention; FIGS. 2A-2D depict exemplary intermediate and final structures formed in accordance with the method of FIG. 1; FIG. 2E depicts exemplary patterned probes formed in accordance with the method of FIG. 1; FIGS. 2F-2G depict scanning electron microscope (SEM) images of sidewall profiles of the exemplary patterned probes formed in accordance with the method of FIG. 1; 2101715-001260 -4- FIGS. 3A-3D depicts SEM images exemplary embodiments of one or more patterned probes formed in accordance with the methods of FIG. 1; FIGS. 4A-4C depict a cross-sectional SEM image of a profile of the patterned probes fabricated in accordance with the method of FIG. 1; FIGS. 4D-4F depict cross-sectional SEM images of respective profiles of exemplary embodiments of a patterned probe fabricated in accordance with the method of FIG. 1; FIGS. 4G-4H depict SEM images of exemplary embodiments of a plurality of patterned probes distributed across a substrate and fabricated in accordance with the method of FIG. 1; FIG. 5 depicts an exemplary method of fabricating at least one patterned probe in accordance with another embodiment of the invention; FIG. 6A depicts a cross-sectional SEM image of exemplary patterned probes formed in accordance with the method of FIG. 5; FIG. 6B depicts a titled SEM image of exemplary patterned probes formed in accordance with the method of FIG. 5; FIG. 6C depicts a magnified view of a distal end of the patterned probe of FIG. 6B; FIG. 7 depicts an exemplary method of fabricating a system having a micro- mechanical spring and a plurality of patterned probes in accordance with an embodiment of the invention; FIG. 8A depicts an SEM image of the patterned probes formed in accordance with the method of FIG. 7; FIG. 8B depicts an SEM image of the micro-mechanical spring formed in accordance with the method of FIG. 7; FIG. 8C depicts an SEM image of the system formed in accordance with the method of FIG. 7; and FIGS. 9A-9B depict SEM images of a plurality of patterned probes distributed across a substrate and fabricated in accordance with the method of FIG. 1. DETAILED DESCRIPTION OF THE INVENTION Although the invention is illustrated and described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the invention. Additionally, various forms and embodiments of the invention are illustrated in the figures. It will be 2101715-001260 -5- appreciated that the combination and of some or all features of any of the embodiments with other embodiments is specifically contemplated herein. Accordingly, this detailed disclosure expressly includes the specific embodiments illustrated herein, combinations and sub-combinations of features of the illustrated embodiments, and variations of the illustrated embodiments. Various terms are used throughout the disclosure to describe the physical shape or arrangement of features. In the description, relative terms such as "horizontal," "vertical," “left,” “right," "down" and "up" as well as derivatives thereof (e.g., "horizontally," "downwardly," "upwardly," etc.) should be construed to refer to the orientation as then described or as shown in the drawing figure under discussion. These relative terms are for convenience of description and normally are not intended to require a particular orientation. For example, as used throughout the specification, the term “horizontal” is not limited to mean planar or horizontal relative to ground, and “vertical” does not necessarily mean perpendicular to horizontal (or to ground), and these terms are used as relative terms to one another. In general, aspects of the invention relate to apparatuses, systems, and methods for fabricating patterned probes, including a micro-mechanical spring with arbitrarily pattern probes (sAPP) at the spring apex, for multiple applications, including but not limited to, material characterization, strain engineering, structural design, and optomechanical sensing. For example, the inventive patterned probes described herein and methods of fabricating the same, including methods of patterning of silicon and silicon oxide nanocones onto the surfaces of devices, introduces characteristics such as anti-reflection and super-transmissivity. As used herein, the term “patterned probes” and nanostructures may be used interchangeably to refer to the structures as described herein. The term “nanocones” may be used in reference to certain embodiments, as an example, without limiting the invention to any particular geometric structures. Further, the term “arbitrary” and “arbitrarily” is used to indicate that the apparatuses, systems, and methods disclosed herein are not intended to be limited to certain parameters, including but not limited to the geometry, shape, pattern, distribution, size, material, and application, of the patterned probes or intermediary structures formed in the disclosed methods of fabricating the patterned probes (discussed further below). In one aspect of the invention, a single-mask all-dry etching method to fabricate patterned probes, such as sharp SiOx nanocones having sharp and high-aspect-ratio nanocones with smooth sidewalls and arbitrary distribution defined by electron beam lithography, is provided. In this way, the patterned probes formed by the inventive methods described herein have advantages, including facilitating the fabrication of 2101715-001260 -6- patterned probes, such as (transparent) nanocones, distributed in a pattern or arbitrarily onto unconventional films and substrates, such as when fused silica and thermally oxidized silicon are unavailable. In another aspect of the invention, a multi-step dry etching method to fabricate patterned probes, such as ultra-sharp amorphous silicon oxide nanocones, is provided. In this way, the patterned probes formed by the inventive methods described herein have advantages in the fabrication of amorphous nanocone arrays onto arbitrary substrates or as nanoscale probes. Referring now to FIGS. 1 and 2A-2G, an exemplary method 1000 of fabricating a plurality of patterned probes, is disclosed. Generally, method 1000 includes: step 1100 of depositing a plurality of layers on a substrate; step 1200 of exposing the plurality of layers, thereby forming at least one intermediary patterned probe arranged in a pattern; step 1300 of depositing a hard mask layer on the plurality of layers; step 1400 of performing a liftoff of portions of the hard mask layer, thereby forming a sample; step 1500 of placing the sample into an inductively-coupled plasma (ICP) chamber; step 1600 of flowing etching gas into the chamber; and step 1700 of etching portions of the sample to form the plurality of patterned probes distributed across the substrate. Additional details of method 1000 will now be discussed below. In a step 1100, a plurality of layers is deposited on a substrate. In an exemplary embodiment, as shown in FIG. 2A, step 1100 includes depositing a plurality of layers 200 on a substrate 100. The plurality of layers 200 include a silicon-containing film (e.g., a silicon oxide film, a silicon nitride film, etc.) and a non-silicon bilayer resist developed on the silicon-containing film. In one non-limiting example, the substrate comprises silicon (Si). Additionally or optionally, the plurality of layers 200 include a silicon oxide film 210, such as a Plasma-enhanced chemical vapor deposition (PECVD) silicon oxide (SiOx) film 210, deposited on the Si substrate 100 and a bilayer resist spun or developed on the PECVD SiOx film. In a non-limiting example, the bilayer 220 resist includes a liftoff resist layer 222 and a positive-tone electron beam resist layer 224. Thus, in an exemplary embodiment, at least one layer of SiOxfilm 210 was deposited at 300°C onto pre-cleaned Si substrates 100 using PECVD (Plasma-Therm Versaline). The at least one layer of SiOxfilm 210 has a thickness in a range of 1-3 μm, individually or collectively. One skilled in the art would understand from the description herein that the thickness of the at least one layer of film 210 is not limited, and can vary based on certain parameters, including, but not limited to desired physical characteristics of the resulting patterned probes. Additionally or optionally, the bilayer 2101715-001260 -7- 220 resist includes the liftoff resist 222 Kayaku Advanced Materials, Inc.) and positive-tone electron beam resist 224 (AR-P 6200.04, Allresist). Additionally or optionally, after performing step 1100, the substrate 100 and the plurality of layers 200 formed thereon are placed into an oxygen plasma asher to remove residual material from the plurality of layers 200. In a non-limiting example, the substrate 100 and the plurality of layers 200 formed thereon are placed into an oxygen plasma asher (Branson / IPC 3000) to remove residual material from the plurality of layers 200, such as to remove residual material from the bilayer resist 200. In a step 1200, the plurality of layers is exposed. In an exemplary embodiment, as shown in FIG. 2B, step 1200 includes exposing the plurality of layers 200, thereby forming at least one intermediary nanostructure 300 arranged in a pattern. In a non- limiting example, the plurality of layers 200 are exposed using electron beam lithography (EBL, Raith EBPG5200ES) to form intermediary structures 300, such as structures being in a range of 50-300 nm in width, in a pattern. Additionally or optionally, patterns of the intermediary structures 300 include 3mm-long lines of various widths for formation of plasma-enhanced chemical vapor deposited silicon oxide nanocone (pSON) wedges. In a non-limiting example, a circular patterns of the intermediary structures 300 were defined for pSON formation. However, one skilled in the art would understand from the description herein that the invention is not limited to a specific pattern of the intermediary structures 300, such as that illustrated in the figures. Rather, the pattern or arrangement of the intermediary structures 300 may be varied to satisfy certain application requirements. In a step 1300, a hard mask layer is deposited on the plurality of layers. In an exemplary embodiment, as shown in FIG. 2C, step 1300 includes depositing a hard mask layer 400 on the plurality of layers 200. The hard mask layer 400 includes an alumina hard-mask layer 400 having a thickness of at least 40 nm. One skilled in the art would understand from the description herein that as the thickness of the silicon oxide layer 210 increases, it may be necessary to correspondingly increase the thickness of the alumina hard-mask layer 400. Additionally or optionally, an in-plane width of the deposited alumina hard-mask layer 400 is in a range between 60 nm to 300 nm. Additionally or optionally, the hard mask layer 400 is deposited using electron- beam evaporation (PVD Products). In a step 1400, a liftoff of portions of the hard mask layer is performed, thereby forming a sample. In an exemplary embodiment, step 1400 includes performing a liftoff of portions of the hard mask layer 400 is performed, thereby forming a sample 410. In 2101715-001260 -8- this way, the arbitrarily shaped hard 400 after performing steps 1300-1400 permits control of the three-dimensional shape of the resulting patterned probes 500. In a step 1500, the sample 410 is placed into an inductively coupled plasma (ICP) chamber. In an exemplary embodiment, as shown in FIG. 2D, step 1500 includes placing the sample 410 into an ICP chamber. Additionally or optionally, the ICP chamber includes a fluorine-based ICP chamber. In an exemplary embodiment, anisotropic dry-etching of the SiOx films 210 was performed in a fluorine-based ICP (F- ICP) chamber or system (F-ICP, Plasma-Therm Apex SLR) with the carrier wafer held at 20°C. Additionally or optionally, prior to performing step 1500, oxygen plasma is distributed throughout the chamber for a first duration as a cleaning step. The first duration includes at least 10 minutes. In a step 1600, etching gas is flowed into the chamber. In an exemplary embodiment, step 1600 includes flowing etching gas into the ICP chamber, and the etching gas includes fluorine compound etching gas. In a non-limiting example, the fluorine compound etching gas includes trifluoromethane (CHF3), octafluorocyclobutane (C4F8), or a combination thereof. Additionally or optionally, the etching gas flows and / or distributed into the chamber for a second duration. Additionally or optionally, the etching gas is allowed to flow through the ICP chamber for a duration (e.g., 5 minutes) prior to sparking the plasma to ensure flushing of contaminant gases. In a step 1700, portions of the sample are etched to form the plurality of patterned probes distributed across the substrate. In an exemplary embodiment, as shown in FIG. 2E, step 1700 includes etching portions of the sample 410 to form the plurality of patterned probes 500 distributed across the substrate 100. In a non-limiting example, portions of the sample 410 are etched for a third duration, such as at least 4 minutes. One skilled in the art would understand from the description herein that height H (FIGS. 2E, 4E) of the patterned probe 500 is directly proportional to the etch duration of step 1700. Accordingly, in one non-limiting example, patterned probes 500 with a height (H) smaller than 1 micron will be etched for a duration of less than 10 minutes. In an exemplary embodiment, step 1700 includes forming the plurality of patterned probes 500, with each patterned probe 500 having a vertical sidewall 520 or a tapered sidewall 530 relative to a horizontal surface 110 (FIGS. 2F-2G, 4G) defined by the substrate 100. In one non-limiting example, step 1500 includes setting an RF power of 30W and an ICP power of 600W, setting the ICP chamber to have a power density of 1.6W / cm2and a substrate-induced bias voltage of 97V. Additionally or optionally, the ICP chamber has a chamber pressure of 8 mTorr and step 1600 includes 2101715-001260 -9- flowing the etching gas comprising CHF3 oxygen at a rate of 45 standard cubic centimeter per minute (sccm) and 5 sccm, respectively, thereby forming the plurality of patterned probes having the vertical sidewall 520. As shown in FIG. 2F, for example, a cross-sectional SEM image illustrates the profiles of the vertical sidewalls 520 of the patterned probes 500 formed after performing etching step 1700 for at least 4 minutes. From left to right, the in-plane widths (W) of the deposited alumina hard-masks are 300 nm, 200 nm, 100 nm, 80 nm, and 60 nm, respectively. The resulting patterned probes 500 have vertical sidewalls 520 (e.g., relative to horizontal surface 110 of the substrate 100). One skilled in the art would understand from the description herein that the vertical sidewall 520 includes a sidewall extending from and at an angle (Xº) angle relative to horizontal surface 110 that deviates by some 10 degrees from perpendicular relative to horizontal surface 110. Additionally or optionally, a slight undercutting near a base 510 can be observed. In another non-limiting example, step 1500 includes setting an RF power of 30W and an ICP power of 300W, and wherein the ICP chamber has a power density of 0.95W / cm2. Additionally or optionally, the ICP chamber has a chamber pressure of 8 mTorr, and wherein step 1600 includes flowing the etching gas comprising CHF3and C4F8at a rate of 30 sccm and 40 sccm, respectively, thereby forming the plurality of patterned probes 500 having the tapered sidewall 530. Additionally or optionally, as shown in FIG. 4C, the plurality of patterned probes 500 each has a plasma-enhanced chemical vapor deposited silicon oxide nanocone (pSON) wedge having a tapered sidewall 530 with a sidewall angle (^^) of 70º relative to the substrate 100. Still further, as shown in FIG. 4C, a plurality of patterned probes 500 can be arranged in an array, each of the plurality of patterned probes 500 having tapered sidewalls 530 with a respective first sidewall angle (^^^) relative to the substrate 100 and a respective second sidewall angle (^^ଶ) relative to the substrate 100, and the respective first sidewall angles (^^^) and the respective second sidewall angles (^^ଶ) vary from each other by less than 3 degrees. As shown in FIG. 2G, for example, a cross-sectional SEM image illustrates the profiles of the tapered sidewalls 530 of the patterned probes 500 formed after performing etching step 1700 for at least 4 minutes. From left to right, the in-plane widths (W) of the deposited alumina hard-masks are 300 nm, 200 nm, 100 nm, 80 nm, and 60 nm, respectively. The resulting patterned probes 500 have tapered sidewalls 530 (relative to horizontal surface 110 of the substrate 100). In an exemplary embodiment, method 1000 includes a step of tuning one or more steps of method 1000 to control one or more predetermined parameters of the 2101715-001260 -10- plurality of patterned probes 500. The parameters include a distribution, a symmetry, a number, and a sidewall angle of the plurality of patterned probes 500. Additionally or optionally, the predetermined parameters include a shape of the sample 410 after performing step 1400, a material of any one of the plurality of layers 200 or substrate 100, and a duration of performing any of steps 1500 to 1700. Referring to FIGS. 3A-3D and FIGS. 4A-4H, exemplary embodiments of the plurality of patterned probes 500 are illustrated. In one non-limiting example, the plurality of patterned probes 500 include a plurality of nanocones, such as dielectric nanocones and plasma-enhanced chemical vapor deposited silicon oxide nanocones (pSONs). In another non-limiting example, the plurality of patterned probes 500 include: a plurality of patterned probes having parallel ridges or parallel triangular prisms with semi-conical ends (FIG. 3A); a plurality of triangular prisms with semi- conical ends surrounding and parallel to base edges of a truncated tetrahedron (Fig. 3B); clusters of semi-conical structures distributed along a circle that defines the cross section of a central cavity (FIG. 3C); and a hollow ring with semi-conical cross sections defining a perimeter of a circle (FIG. 3D). Regarding FIG. 3A, for the plurality triangular prisms with semi-conical ends, the triangle may be a trapezoid and the cone may be truncated, especially when viewed at a high enough resolution. Likewise, regarding FIG. 3B, for the plurality triangular prisms with semi-conical ends, the triangle may be a trapezoid and the cone may be truncated, especially when viewed at a high enough resolution. However, one skilled in the art would understand from the description herein that the invention is not limited to the specific geometry or arrangement of the plurality of patterned probes 500 illustrated in the figures. Additionally or optionally, the plurality of patterned probes 500 each has a uniform or smooth surface having minimum surface roughness as compared to, for example, a surface roughness of the portion 110 of the substrate 100 between adjacent patterned probes 500 (as shown in FIG. 4G, discussed below). One skilled in the art would understand from the description herein that “smooth” may be measured, observed, or defined, in part, via surface roughness (e.g., as qualitatively observed via an imaging device). For example, by visual comparison with a relatively flat surface 110 of the substrate 100, as shown in FIG. 4G, the surface roughness of the flat surface 110 is approximately 0.5-2 nanometers and there are noticeable rough patches 112 that are not visible on the sidewalls patterned probes 500. Turning now to FIGS. 4A-4H, SEM images illustrate and confirm a uniformity of the surface of the patterned probes 500, as well as uniformity of the arrangement or 2101715-001260 -11- distribution of the patterned probes the substrate 100, within the limits of the capabilities of electron beam lithography (EBL) systems. FIG. 4A shows a cross- sectional SEM image of a pSON wedge 500 formed after increasing the tapered etch time of step 1700 to 16 minutes. Using SEM, an SiOx etch depth is measured as approximately 880 nm, giving an etch rate of 0.92 nm / s. This indicates that the etch depth scales linearly with time and pSONs of arbitrary height can be fabricated provided the etch selectivity is sufficient. FIG. 4B shows a magnified view of a distal end of the pSON wedge 500 of FIG. 4A. In FIGS. 4B-4C, the pSON wedge 500 was imaged covered with photoresist and imaged at a lower accelerating voltage to improve contrast between the alumina hard mask 400 and pSON wedge 500. Specifically, FIG. 4B shows the distal end 540 (e.g., sharp rounded tip or apex) prior to removal of the hard mask layer 400 in step 1400. As can be seen in FIGS. 4B and 4C, no undercutting of the alumina hard-mask 400 is observed, indicating that pSONs 500 having sharp distal ends 540 may be achievable by decreasing the in-plane width of the hard-mask layer 400 even further. SEM was further used to measure the remaining thickness of the alumina hard-mask 400 following the etch step 1700 and observed that greater than 30 nm of the alumina hard-mask 400 remains, which advantageously gives a selectivity of >88. The selectivity of >88 indicates that a structure (e.g., patterned probe 500 or an intermediary structure) which is 88 times taller in height than a thickness of the hard mask layer 400 can be etched using method 1000. This is consistent with characterization of the patterned probes 500 fabricated by method 1000 as having a “high” or “very high” aspect ratio (e.g., having a height to width ratio of at least 10:1). An expanded view of FIG. 4B is shown in Fig. 4C and shows the result of etching closely spaced patterns of varying widths. The widths of the defined hard masks from left to right in FIG. 4C are 60 nm, 80 nm, 100 nm, 200 nm, and 300 nm. As stated above, each of the plurality of patterned probes 500 have tapered sidewalls 530 with the respective first sidewall angle (^^^) relative to the substrate 100 and the respective second sidewall angle (^^ଶ) relative to the substrate 100. It is noted that because the plane where two neighboring sidewalls intersect behaves as an etch-stop, the trenches 542 formed between adjacent patterned probes 500 are relatively sharp (e.g., relative to the flat horizontal surface 100 of the substrate 100). In an exemplary embodiment, closely spaced pSONs 500 may therefore be employed as nano-imprint lithography stamps resulting in very sharp structures of varying heights as dependent on the spatial variation of patterned probes 500 within the stamp. 2101715-001260 -12- Turning now to FIGS. 4D-4F, 210 of thickness 1 μm, 2 μm, and 3 μm were considered and the resulting pSON wedges 500 are shown in the cross-sectional SEM images in FIGS. 4D-4F, respectively. The sidewall angles (^^^,ଶ) (FIG. 4C) of the resulting nanostructures 500 were measured to be approximately 70 degrees, indicating that the sidewall angle (^^^,ଶ) is independent of etching depth. The pSONs 500 in FIG. 4G are the result of etching portions of the sample 410 with circular alumina masks 400 placed or arranged at the four corners of a square and demonstrate both smooth sidewalls and etch baseline relative to the closely spaced pSON wedges (FIG. 4H). As shown in FIG. 4H, pSONs 500 patterned with variation in the pSON density and sidewall overlap reveal that method 1000 facilitates fabrication of repeatable, uniform, and high-quality pSONs 500 with highly deterministic placement. Referring now to FIGS. 5 and 6A-6C, an exemplary method 2000 of fabricating a plurality of patterned probes, is disclosed. Method 2000 is similar and incorporates similar steps and feature recited above with respect to method 1000. However, method 2000 differs in some respects as will be discussed further below. Generally, method 2000 includes: step 2100 of depositing a plurality of layers on a substrate that defines a horizontal surface; step 2200 of exposing the plurality of layers, thereby forming a pattern of at least one intermediary patterned probe; step 2300 of depositing a hard mask layer on the plurality of layers; step 2400 of performing a liftoff of portions of the hard mask layer, thereby forming a sample; step 2500 of placing the sample into an inductively-coupled plasma (ICP) chamber; step 2600 of flowing etching gas into the chamber; and step 2700 of etching portions of the sample to form the plurality of patterned probes distributed across the substrate. Additional details of method 2000 will now be discussed below. In step 2100, a plurality of layers is deposited on a substrate that defines a horizontal surface. In an exemplary embodiment, step 2100 includes depositing a plurality of layers 200 on a substrate 100 that defines a horizontal surface 110. As stated in step 1100 of method 1000, the plurality of layers 200 includes a silicon- containing film 210 and a non-silicon bilayer resist 220 developed on the silicon- containing film 210. In a step 2200, the plurality of layers 200 is exposed. In an exemplary embodiment, step 2200 includes exposing the plurality of layers 200, thereby forming at least one intermediary nanostructure 300 arranged in a pattern. Step 2200 includes similar steps and features as recited above with respect to step 1200 of method 1000. In a step 2300, a hard mask layer is deposited on the plurality of layers. In an exemplary embodiment, step 2300 includes depositing a hard mask layer 400 on the 2101715-001260 -13- plurality of layers 200. Additionally or an in-plane width of the deposited hard-mask layer is in a range between 60 nm to 100 nm. Step 2300 includes similar steps and features as recited above with respect to step 1300 of method 1000. In a step 2400, a liftoff of portions of the hard mask layer is performed, thereby forming a sample. In an exemplary embodiment, step 2400 includes performing a liftoff of portions of the hard mask layer 400 is performed, thereby forming a sample 410. Step 2400 includes similar steps and features as recited above with respect to step 1400 of method 1000. In a step 2500, the sample 410 is placed into an inductively coupled plasma (ICP) chamber. In an exemplary embodiment, step 2500 includes placing the sample 410 into an ICP chamber. Step 2500 includes similar steps and features as recited above with respect to step 1500 of method 1000. However, step 2500 differs from step 1500 in that steps 1600 to 1700 are performed without distributing oxygen plasma throughout the chamber for a first duration as a cleaning step prior to performing step 1500. In a step 2600, etching gas is flowed into the chamber. In an exemplary embodiment, step 2600 includes flowing etching gas into the ICP chamber, and the etching gas includes fluorine compound etching gas. In a non-limiting example, the fluorine compound etching gas includes trifluoromethane (CHF3), octafluorocyclobutane (C4F8), or a combination thereof. In a step 2700, portions of the sample are etched to form the plurality of patterned probes distributed across the substrate. In an exemplary embodiment, as step 2700 includes etching portions of the sample 410 to form the plurality of patterned probes 600 distributed across the substrate 100. In an exemplary embodiment, each of the plurality of patterned probes 600 includes a sidewall profile having a first portion 610 between an attachment 612 to the substrate 100 and an inflection region 614, and a second portion 620 between the inflection region 614 and a distal end 640. Additionally or optionally, the first portion 610 and the second portion 620 have different profile characteristics. In a non-limiting example, the respective distal ends 640 of the plurality of patterned probes 600 each has a tip or apex diameter upper bound of a range of 6.5 to 10.7 nm or less (e.g., 8.6 ± 2.1 nm). In an exemplary embodiment, the respective distal ends 640 of the plurality of patterned probes 600 each has a tip or apex diameter upper bound of less than 11 nm. In an exemplary embodiment, in step 2600, the etching gas flows for a first duration. Step 2700 includes a first sub-step of forming the plurality of patterned 2101715-001260 -14- probes 600 having a tapered profile in at least the first portion 610 of the sidewall profile. In a non-limiting example, the tapered first portion 610 has a height of at least 500 nm. Additionally or optionally, in step 2600, the etching gas is flowed for a second duration. Step 2700 includes a second sub-step of forming the second portion 620 of the sidewall having a vertical profile characteristic in the second portion 620 of the sidewall profile. In a non-limiting example, the second sub-step is performed after the first sub-step and without distributing oxygen plasma within the ICP chamber in between performing the first sub-step and the second sub-step. Additionally or optionally, the first duration (e.g., at least 4 minutes) is different from the second duration (e.g., at least 2 minutes). In an exemplary embodiment, method 2000 includes repeating the first sub-step and the second sub-step. FIG. 6A shows a cross-sectional SEM image of the resulting patterned probes 600, with etching for 60, 80, 100, 200, and 300 nm alumina hard-mask layer 400 (from left to right). The second portion 620 (e.g., top half) of the etched pSON wedges 600 has a nearly vertical profile characteristic (e.g., relative to horizontal surface 110 of substrate 100, for example) with a slight undercut toward the middle of the wedge or the inflection region 614, while the first portion 610 (e.g., bottom half) has a tapered profile characteristic. As the width (W) of the hard-mask layer 400 decreases, the middle (or inflection region 614) of the pSON wedges 600 experience more significant “necking” effect, until a full undercut occurs at a central region of the structures 600 defined by a 60-nm-wide alumina hard mask 400. The remaining bottom half (e.g., first portion 610) of the structure 600 is an ultra-sharp pSON wedge of height of approximately 500 nm, which is half the height of the original SiOx film 210 in an exemplary embodiment. While only the 60 nm hard-mask experiences a full undercut (leftmost patterned probe 600 in FIG. 6A), ultra-sharp pSONs from both the 80- and 100-nm-wide hard-masks are nevertheless made possible by method 2000. FIG. 6C is a magnified image of the pSON apex 640 and depicts a smooth sidewall terminated by a qualitatively ultra-sharp tip having an apex diameter upper bound of a range of 6.5 to 10.7 nm or less (e.g., 8.6 ± 2.1 nm), in accordance with an exemplary embodiment. As used herein, the term “ultra-sharp” indicates that the patterned probe 600 (or portions thereof) has an apex diameter of ~10 nm or less and / or was fabricated using a multi-step etching method, such as method 2000. As used herein, terms such as “about” or the “~” in, e.g., “~10”, means + / - 10% (i.e. “~10 nm or less” is equivalent to “<11 . Thus, advantageously, method 2000 makes possible the fabrication of ultra-sharp patterned probes 600 using amorphous materials. 2101715-001260 -15- In an exemplary embodiment, 2000 includes a step of tuning one or more steps of method 2000 to control one or more predetermined parameters of the plurality of patterned probes 600. The predetermined parameters include wherein the predetermined parameters comprise a distribution, a symmetry, a number, a sidewall angle (^^^,ଶ), an apex radius, and an apex aspect ratio of the plurality of patterned probes 600. Although the above embodiments of the inventive methods are described herein with certain predetermined parameters or in the context of specific applications, one skilled in the art would understand from the description herein that the invention is not so limited. Rather, the described methods can be modified for various conditions and applications, e.g., the single-mask all-dry etching method can be extended to low- temperature PECVD grown SiOx films for nanocone formation on polymer-based and flexible substrates, which may have applications in functionalized needle arrays for drug delivery or flexible optical devices, or nanosphere lithography to enable high throughput manufacturing; the multi-step dry etching method can be extended to photolithography techniques. In a non-limiting example, an atomic force microscopy (AFM) cantilever comprising the plurality of patterned probes 500, 600 is fabricated in accordance with the steps of method 1000 or method 2000. In another non-limiting example, a scanning probe tip having the plurality of patterned probes 500, 600 fabricated in accordance with the steps of method 1000 or method 2000. In yet another non-limiting example, as shown in FIGS. 8A-8C (discussed further below), a micro-mechanical spring with arbitrarily patterned probes (sAPP) system 4000 includes a plurality of conical arbitrarily patterned probes 500, 600, each comprising a patterned probe 500, 600 fabricated in accordance with the steps of method 1000 or method 2000. The plurality of conical arbitrarily patterned probes 500, 600 is coated with a thin film of material. Additionally or optionally, the plurality of conical arbitrarily patterned probes 500, 600 is distributed such that respective distal ends 540, 640 of the plurality of conical arbitrarily patterned probes 500, 600 are arranged within a spot size of a laser or scanning device. Additionally or optionally, the micro-mechanical spring has a spring constant and a resonant frequency, each of which is tunable by modifying one of: a spring arm width, a number of spring arms, spacing between the number of spring arms, and a surface area coverage of a plurality of layers arranged in a stacking order, each layer having a pattern, a material, and a thickness. 2101715-001260 -16- Turning now to FIGS. 7 and 8A- method of fabricating a system comprising a micro-mechanical spring with a plurality of patterned probes is provided. In an exemplary embodiment, method 3000 is described in context of the system 4000 comprising the micro-mechanical spring 4100 (FIG. 8B) with a plurality of patterned probes 4200 (FIG. 8A). Generally, method 3000 includes steps of: step 3100 of fabricating the micro-mechanical spring; step 3200 of fabricating patterned probes; and step 3300 releasing the micro-mechanical spring. In step 3100, the micro-mechanical spring is fabricated. In an exemplary embodiment, with reference to FIG. 8B, step 3100 includes fabricating the micro- mechanical spring 4100 by: (i) developing a patterned hard mask layer over a substrate; (ii) etching portions of the substrate for a duration; (iii) removing portions of the hard mask; (iv) removing silicon (Si) oxidation from the substrate, and (v) developing at least one patterned strain patch on the substrate, thereby forming a sample. Additionally or optionally, in step (i), the patterned substrate hard mask layer over the substrate includes chromium (Cr) hard mask over a silicon-on-insulator substrate. Additionally or optionally, in step (iii), the hard mask comprises a Cr hard mask. Additionally or optionally, in step (v), the at least one patterned strain patch comprises a patterned Cr strain patch. Any material or solid that can be deposited using conventional deposition techniques (e.g., evaporation, sputtering, chemical vapor deposition, etc.), can be used in place of chromium. In principle, the deformation of the micro-spring upwards is related to residual stresses between the “strain patches” and the spring 4100 material (e.g., silicon). The amount of residual stress depends on several factors, including but not limited to thermal expansion coefficient, which varies from material to material. Consequently, the height of the spring 4100, the spring constant, and resonant frequency of the spring 4100 can be influenced by at least the choice of material. Use of phase-change materials is also possible, in which case the residual stress changes with temperature, for example. Accordingly, deformation of the spring can be controlled via at least choice of material (and the resulting characteristics of the spring 1400 influenced or affected). A more detailed “Recipe” for manufacturing an exemplary micro-mechanical spring 4100 is provided at the end of the Examples section. In step 3200, the arbitrarily patterned probes are fabricated. In an exemplary embodiment, with reference to FIG. 8A, step 3200 includes fabricating the arbitrarily patterned probes 4200 in accordance with one or more of methods 1000 and 2000. In another exemplary embodiment, step 3200 includes fabricating arbitrarily patterned probes by: (i) depositing one or more layers on the sample coating; (ii) depositing a 2101715-001260 -17- hard mask layer on the one or more containing plurality of layers, thereby forming a second sample; (iii) placing the second sample into an inductively-coupled plasma (ICP) chamber; (iv) flowing etching gas into the ICP chamber, the etching gas comprising a trifluoromethane (CHF3) and octafluorocyclobutane (C4F8); and (v) etching portions of the second sample to form at least one patterned probe. Additionally or optionally, in step (i), depositing one or more layers on the sample coating includes depositing one or more silicon-containing layers on the sample coating. In step 3300, the micro-mechanical spring is released. In an exemplary embodiment, with reference to FIG. 8C, step 3300 includes releasing the micro- mechanical spring, thereby forming the sAPP system 4000 (FIG. 8C). EXAMPLES The co-inventors assessed the exemplary systems and methods as disclosed herein in a clinical or laboratory setting, to validate feasibility and functionality of the components of the subject systems, as well as verified any updates or improvements made. “Single-mask fabrication of sharp SiOx nanocones” Materials and Methods The inventive plasma-enhanced chemical vapor deposited silicon oxide nanocones (pSON) fabrication sequence is summarized in FIGS. 2A-2G. Frist, as shown in FIG. 2A, 1 μm thick silicon oxide films were deposited at 300°C onto pre-cleaned Si substrates using PECVD (Plasma-Therm Versaline). As shown in FIG. 2B, a bilayer resist procedure is performed for improved liftoff performance of the hard mask. Liftoff resist (LOR3A, Kayaku Advanced Materials, Inc.) and positive-tone electron beam resist (AR-P 6200.04, Allresist) were spun onto the sample and subsequently exposed using electron beam lithography (EBL, Raith EBPG5200ES) to write structures between 50- 300 nm in width. Patterns consisting of 3mm-long lines of various widths were written for formation of pSON wedges and cross-sectional scanning electron microscopy (SEM). Circular patterns were defined for pSON formation. Following development of the resists, samples were placed into an oxygen plasma asher (Branson / IPC 3000) to remove resist residuals. As shown in FIG. 2C, a 40-nm-thick alumina hard-mask was then deposited using electron-beam evaporation (PVD Products), followed by liftoff of excess alumina. As shown in FIG. 2D, anisotropic dry-etching of the SiOx films was performed in a fluorine-based ICP (F-ICP) system (F-ICP, Plasma-Therm Apex SLR) with the carrier wafer held at 20°C. Prior to placing samples in the chamber, the F-ICP chamber was cleaned in oxygen plasma for 10 minutes. Samples were then placed in the chamber 2101715-001260 -18- and etching gases were allowed to flow the chamber for 5 minutes prior to sparking the plasma to ensure flushing of contaminant gases. Cross-sectional SEM images of the profiles of vertical and tapered etches were then compared in FIGS. 2F and 2G, respectively. In both cases, the total etch time was 4 minutes. From left to right, the in-plane widths of the deposited alumina hard-masks are 300, 200, 100, 80, and 60 nm. The vertical sidewall profiles in FIG. 2F were achieved by flowing CHF3 and O2 at rates of 45 and 5 sccm, respectively, while holding a chamber pressure of 8 mTorr. The RF power was set to 30W while the ICP power was set to 600W. The vertical etching process has an etch rate of ~1.98 nm / s and results in nanostructures with relatively vertical sidewalls but slight undercutting near the base of the etch. To achieve a tapered etch as in FIG. 1G, we replace O2 with C4F8 and set the flow rates of CHF3 and C4F8 to 30 and 40 sccm, respectively. The RF power was set to 30W, the ICP power to 300W, and the chamber pressure to 8 mTorr. The power density within the ICP chamber during the tapered etch is ~1.6W / cm2 and the substrate- induced bias voltage is ~97V. Compared to the vertical etch, the tapered etch is significantly slower at a rate of ~0.95 nm / s and results in pSON wedges with linear sidewalls of angle ~70 degrees. Results To confirm the uniformity of patterned pSON distributions, the fabricated samples having at least one nanostructure underwent SEM imaging. The uniformity was determined to be excellent, limited mainly by the capabilities of the EBL system and the optimization of exposure recipes. For example, FIG. 4A shows an up-close cross- sectional SEM image of a pSON wedge formed after increasing the tapered etch time to 16 minutes. Using SEM, SiOx etch depth is measured to be approximately 880 nm giving an etch rate of 0.92 nm / s, in excellent agreement with the etch rate measured after a 4 minute etch. This indicates that the etch depth scales linearly with time and pSONs of arbitrary height can be fabricated provided the etch selectivity is sufficient. A second sample having at least one nanostructure was fabricated using identical etching conditions, covered with photoresist, and imaged at a lower accelerating voltage to improve contrast between the alumina hard mask and pSON wedge. FIG. 4B shows the sharp rounded tip or apex prior to removal of the hard mask. As can be seen in FIGS. 4B and 4C, there does not appear to be any undercutting of the alumina hard-mask, indicating that much sharper pSONs may be achievable by decreasing the in-plane width of the hard-mask even further. SEM is used to roughly measure the remaining thickness of the alumina hard-mask following 2101715-001260 -19- the etch and find that greater than 30 which gives a selectivity of >88. The low etch rate of alumina in ICP RIE involving passivating fluorocarbons is known and, together with the absence of undercut observed, may enable extremely sharp pSONs with very high aspect ratio, limited only by resolution limits of EBL. However, the slow etch rate of the presented pSON etch process, along with stability of high aspect ratio masks, may affect the limitations of such structures. As used herein, “high aspect ratio” describes structures (e.g., patterned probes 500, 600) or portions thereof as having a height to width ratio of at least 10:1. An expanded view of FIG. 4B is shown in FIG. 4C which shows the result of etching closely spaced patterns of varying widths. The widths of the defined hard- masks from left to right are 60, 80, 100, 200, and 300 nm. All sidewall angles ^^ are measured throughout the structure (e.g. ^^^and ^^ଶin FIG. 4C are the two sidewall angles measured for the left-most wedge structure) and find that variation in sidewall angle across the pattern is less than 3 degrees. The spacing-dependent etch depth between neighboring structures, also known as RIE lag, may be due to insufficient recycling of reactive species or trapping of passivating fluorocarbon film within the trenches. Because the plane where two neighboring sidewalls intersect behaves as an etch-stop, the bottoms of the trenches are extremely sharp. Closely spaced pSONs may therefore be employed as nano-imprint lithography stamps resulting in very sharp structures of varying height dependent on the spatial variation of structures within the stamp. Further, multiple SiOx films were prepared to investigate the depth-dependent etching rates and sidewall angle dependence on the aspect ratio of fabricated pSON wedges. SiOx films of thickness 1, 2, and 3 μm were considered and the resulting pSON wedges are shown in the cross-sectional SEM images in FIGS. 4D-4F, respectively. The sidewall angles of the resulting nanostructures were measured to be approximately 70 degrees, indicating that the sidewall angle is independent of etching depth. The pSONs in FIG. 4G are the result of etching SiOx with circular alumina masks placed at the four corners of a square and demonstrate both smooth sidewalls and etch baseline relative to the closely spaced pSON wedges. pSONs patterned with variation in the pSON density and sidewall overlap are shown in FIG. 4H, revealing that a method for fabricating repeatable high-quality pSONs with highly deterministic placement is provided. While fabricated pSONs exhibit smooth sidewalls, undesirable rippling along the sidewalls of etched pSON wedges were observed. FIG. 9A depicts a tilted cross- sectional SEM image showcasing this rippling behavior both within the trenches and 2101715-001260 -20- along the outer-most sidewalls of the To elucidate the origin of sidewall rippling, truncated pSON wedges were fabricated using the tapered etch procedure and the result is displayed in the tilted SEM image of FIG. 9B. The truncated pSON wedge exhibits rippling along the sidewalls while the truncated end of the forms one-half of a nanocone with smooth sidewalls. The rippling along the sidewalls originates from local fluctuations in the SiOx film thickness, leading to local protrusions and depressions for regions that are slightly thicker and thinner, respectively. Optimization of the PECVD deposition conditions to decrease surface roughness may mitigate the sidewall rippling effect. Still further, the inventive systems and methods herein provide a novel all-dry etch process to fabricate ultra-sharp pSONs with tip or apex diameters of ~10nm. This is achieved, at least in part, by utilizing four F-ICP etching steps without removing the sample from the chamber. After repeating the deposition and lithography process as described in FIGS. 6A-6C, the tapered etch process is ran for 4 minutes. Without cleaning the chamber with O2 plasma and after purging all gases, the vertical etch process is ran as described for FIG. 2F for 2 minutes. This two-step etch is repeated a second time and present a cross-sectional SEM image of the final structure in FIG. 6A. The in-plane widths of the defined hard-masks are the same as described for FIG. 2C and the resulting sidewall profile can be described by two separate regions. The top- half of the etched pSON wedges are nearly vertical with a slight undercut toward the middle of the wedge, while the bottom half has a tapered edge. As the width of the hard-mask decreases, the middle of the pSON wedges experience more significant “necking” until a full undercut occurs at the center of the structures defined by a 60- nm-wide alumina hard mask. The remaining bottom half of the structure is an ultra- sharp pSON wedge of height ~500 nm, half the height of the original SiOx film. While only the 60 nm hard- mask experiences a full undercut, the same etch process produces ultra-sharp pSONs from both the 80-nm and 100-nm-wide hard-masks, as shown by the arrays on the left- and right-side of FIG. 6B, respectively. Although not shown, pSONs from the 60-nm-wide hard-masks are destroyed because they are formed at some point during the ongoing etching process and are “blunted” by the continuation of etching. FIG. 6C is a magnified view of the pSON apex and depicts a smooth sidewall terminated by an “ultra-sharp” tip or apex of ~10 nm. This necking and fracture process is similar to that described in the fabrication of silicon AFM probes (see e.g., S. M. Yoon, et. al., “Subwavelength Hollow-Nanopillared Glass with Gradient Refractive Index for Ultralow Diffuse Reflectance and Antifogging”, ACS Appl Mater Interfaces, vol. 12, no. 5, pp. 6234–6242, Feb. 2020, doi: 10.1021 / acsami.9b19228; 2101715-001260 -21- K. X. Wang, et. al., “Absorption in ultrathin crystalline silicon solar cells with antireflection and light-trapping nanocone gratings”, Nano Lett, vol. 12, no. 3, pp. 1616–1619, Mar. 2012, doi: 10.1021 / nl204550q), without the requirement of a wet etching process for final formation. Thus, the inventive methods and systems described herein provide a novel process of fabricating ultra-sharp nanostructures using amorphous materials. Further experimentation of combining etching steps will enable precise control over the morphology of pSON sidewalls. In embodiments, the nanostructures may be referred to as or considered to be “transparent” or “anti-reflective,” meaning that they have negligible absorbance over the measured wavelength range of 400-1500nm). “Recipe for micro-mechanical spring with arbitrarily patterned probes” Substrate: silicon-on-insulator (SOI): 220 nm Si (device) || 3 µm thermal oxide (Buried Oxide) || 725 µm Si (handle) 1) Pattern chromium (Cr) hard mask a. Spincoat LOR5A @ 6000RPM (ramp rate 800RPM / s) for 60 seconds i. Bake at 200°C for 5 minutes b. Spincoat AZ1512 @ 4000RPM (ramp rate 800RPM / s) for 60 seconds i. Bake at 90°C for 90 seconds c. Expose using laser writer i. 165 mJ / cm2d. Post-exposure bake at 110°C for 60 seconds e. Develop LOR5A and AZ1512 in AZ 300 MIF for 120 seconds f. Asher: 10-minute descum g. Deposit 150nm Cr (5Å / s) using e-beam evaporator h. Liftoff in room-temperature N-methyl-2-pyrrolidone (NMP) for 30 minutes 2) Vertical etch of SOI a. Etch Si for 60 seconds i. 25.0 sccm SF6, 20.0 sccm C4F8, 6 mTorr ii. Bias = 5OW iii. ICP = 800W 3) Removal of Cr hard mask a. Place sample in Cr etchant held at 40°C for 30 minutes 2101715-001260 -22- 4) Remove Si oxidation Cr etchant a. Dip sample in 6:1 BOE for 8 minutes 25 seconds 5) Pattern Cr strain patches a. Spincoat photoresists or electron beam resists (e.g., LOR5A, AZ1512, LOR3A, CSAR AR-P 6200.09, etc.) @ 6000RPM (ramp rate 800RPM / s) for 60 seconds i. Bake at 200°C for 5 minutes b. Spincoat AZ1512 @ 4000RPM (ramp rate 800RPM / s) for 60 seconds i. Bake at 90°C for 90 seconds c. Expose using laser writer i. 165 mJ / cm2d. Post-exposure bake at 110°C for 60 seconds e. Develop LOR5A and AZ1512 in a developer solution, such as AZ® 300 MIF for 120 seconds f. Asher: 10-minute descum g. Dip in 6:1 buffered oxide etchant (BOE) for 30 seconds to remove oxidation of silicon from asher h. Deposit 120nm Cr (0.5Å / s) using e-beam evaporator i. Liftoff in room-temperature NMP for 30 minutes 6) PECVD deposit 1 µm SiO2over entire sample (11 minutes 6 seconds) for tips a. 5% SiH4 / He: 360 sccm b. N2O: 1080 sccm c. N2: 1400 sccm d. RF HF power: 65W e. Lower T / Upper T = 300 / 200°C 7) Pattern Al2O3 hard mask for etching of tips a. Spincoat LOR3A @ 6000RPM (ramp rate 800RPM / s) for 60 seconds (approx. 175 nm). i. Bake at 200°C for 5 minutes b. Spincoat CSAR AR-P 6200.09 @ 4000RPM (ramp rate 800RPM / s) for 60 seconds (approx. 70nm) i. Bake at 170°C for 5 minutes c. Expose using e-beam lithography (EBL) i. 1nA 2101715-001260 -23- ii. 250 µC / cm2d. Develop AR-P 6200.09 in a developer solution, such as AR 600- 546 for 60 seconds e. Develop LOR3A in AR 300-47 for 35 seconds f. Asher: 3-minute descum g. Deposit 60nm Al2O3(0.5Å / s) using e-beam evaporator h. Overnight liftoff in room-temperature NMP 8) Etch Tips in F-ICP a. CHF3: 30 sccm, C4F8: 40 sccm, 8 mTorr, Bias= 30W, ICP = 300W, 20 minutes per micron 9) Mask tips for BOE release of springs a. Spincoat a photoresist, such as AZ P4330-RS @ 2000RPM (ramp rate 500RPM / s) for 60 seconds (5µm thick) b. Bake at 110°C for 300 seconds c. Expose using laser writer,at 500 mJ / cm2defocus 2d. Develop in a developer solution, such as AZ® 400K for 8 minutes e. Post-development bake at 110°C for 5 minutes. 10) Release springs a. Place sample in 6:1 BOE for 10 minutes (approx. 160nm / min) for springs with 4µm-wide spring arms b. Rinse sample in a beaker of deionized (DI) water to stop the reaction, and then submerge in a second beaker of DI water. c. Transfer sample in 200 mL isopropyl alcohol (IPA). d. Transfer sample to a beaker with NMP to remove the resist covering the tips. i. Leave sample in NMP beaker for 20 minutes. e. Transfer sample in 200 mL IPA. f. Transfer sample to the critical point dryer (CPD) sample holder. g. Fill the CPD reservoir with IPA about ¼ of the way up. h. Transfer the CPD sample holder to the CPD reservoir. i. Run the CPD. i. After approximately 45 minutes, the sample fabrication will be completed. 2101715-001260 -24- Although the invention is described herein with reference to specific embodiments, the invention is not intended to be limited to the details shown. Rather, various modifications may be made in the details within the scope and range of equivalents of the claims and without departing from the invention.

Claims

2101715-001260 -25- What is claimed:

1. A method of fabricating a plurality of patterned probes, the method comprising: (a) depositing a plurality of layers on a substrate, the plurality of layers comprising a silicon-containing film and a non-silicon bilayer resist developed on the silicon-containing film; (b) exposing the plurality of layers, thereby forming at least one intermediary nanostructure arranged in a pattern; (c) depositing a hard mask layer on the plurality of layers; (d) performing a liftoff of portions of the hard mask layer, thereby forming a sample; (e) placing the sample into an inductively-coupled plasma (ICP) chamber; (f) flowing etching gas into the chamber, the etching gas comprising fluorine compound etching gas; (g) etching portions of the sample to form the plurality of patterned probes distributed across the substrate.

2. The method of claim 1, wherein the fluorine compound etching gas comprises trifluoromethane (CHF3), octafluorocyclobutane (C4F8), or a combination thereof.

3. The method of claim 1, wherein each of the plurality of patterned probes has a uniform surface having minimum surface roughness as compared to a surface roughness of the portion of the substrate between adjacent patterned probes.

4. The method of claim 1, wherein step (a) comprises depositing a silicon oxide film on a silicon substrate.

5. The method of claim 4, wherein the silicon oxide film has a thickness in a range of 1- 3 μm.

6. The method of claim 1, wherein the plurality of patterned probes comprises a plurality of nanocones.

7. The method of claim 1, wherein the plurality of patterned probes comprises a plurality of patterned probes having a plurality of triangular prisms with semi-conical ends.

8. The method of claim 1, wherein the plurality of patterned probes comprises a plurality of triangular prisms with semi-conical ends surrounding and parallel to base edges of a truncated tetrahedron.

9. The method of claim 1, wherein the plurality of patterned probes comprises clusters of semi-conical structures distributed along a circle that defines a cross section of a central cavity.2101715-001260 -26- 10. The method of claim 1, wherein the of patterned probes comprises a plurality of hollow rings with semi-conical cross sections defining a perimeter of a circle.

11. The method of claim 6, wherein the plurality of patterned probes comprises a plurality of dielectric nanocones.

12. The method of claim 4, wherein the plurality of patterned probes comprises plasma-enhanced chemical vapor deposited silicon oxide nanocones (pSONs).

13. The method of claim 1, wherein the at least one intermediary nanostructure has a width in a range of 50-300 nm.

14. The method of claim 1, wherein the pattern is circular.

15. The method of claim 1, wherein after step (a), the substrate and the plurality of layers formed thereon are placed into an oxygen plasma asher to remove residual material from the plurality of layers.

16. The method of claim 1, wherein the hard-mask layer comprises an alumina hard- mask layer having a thickness of at least 40 nm.

17. The method of claim 16, wherein an in-plane width of the deposited alumina hard- mask layer is in a range between 60 nm to 300 nm.

18. The method of claim 1, wherein the hard mask layer is deposited via electron-beam evaporation.

19. The method of claim 1, wherein the ICP chamber comprises a fluorine-based ICP chamber.

20. The method of claim 19, wherein prior to performing step (e), distributing oxygen plasma throughout the chamber for a first duration.

21. The method of claim 20, wherein the first duration comprises at least 10 minutes.

22. The method of claim 1, wherein step (f) comprises flowing the etching gas for a second duration.

23. The method of claim 1, wherein step (g) comprises forming the plurality of patterned probes each having a vertical sidewall or a tapered sidewall relative to a horizontal surface defined by the substrate.

24. The method of claim 1, wherein step (g) comprises etching portions of the sample for a third duration.

25. The method of claim 24, wherein the third duration comprises at least 4 minutes.

26. The method of claim 23, wherein step (e) comprises setting an RF power of 30W and an ICP power of 600W, and wherein the ICP chamber has a power density of 1.6W / cm2and a substrate-induced bias voltage of 97V.

27. The method of claim 26, wherein the ICP chamber has a chamber pressure of 8 mTorr, and wherein step (f) comprises flowing the etching gas comprising CHF3 and2101715-001260 -27- oxygen at a rate of 45 standard cubic per minute (sccm) and 5 sccm, respectively, thereby forming the plurality of patterned probes having the vertical sidewall.

28. The method of claim 23, wherein step (e) comprises setting an RF power of 30W and an ICP power of 300W, and wherein the ICP chamber has a power density of 0.95W / cm2.

29. The method of claim 28, wherein the ICP chamber has a chamber pressure of 8 mTorr, and wherein step (f) comprises flowing the etching gas comprising CHF3 and C4F8 at a rate of 30 sccm and 40 sccm, respectively, thereby forming the plurality of patterned probes having the tapered sidewall.

30. The method of claim 29, wherein the plurality of patterned probes each comprise a plasma-enhanced chemical vapor deposited silicon oxide nanocone (pSON) wedge having a tapered sidewall with a sidewall angle (^^) of 70º relative to the substrate.

31. The method of claim 30, wherein plurality of patterned probes are arranged in an array, each of the plurality of patterned probes having tapered sidewalls with a respective first sidewall angle (^^^) relative to the substrate and a respective second sidewall angle (^^ଶ) relativesubstrate, and the respective first sidewall angles (^^^) and the respective second sidewall angles (^^ଶ) vary from each other by less than 3 degrees.

32. The method of claim 1, further comprising tuning the fabrication method to control one or more predetermined parameters of the plurality of patterned probes.

33. The method of claim 32, wherein the predetermined parameters comprise a distribution, a symmetry, a number, and a sidewall angle of the plurality of patterned probes, the predetermined parameters further comprising a shape of the sample after performing step (d), a material of any one of the plurality of layers or substrate, and a duration of performing any of steps (e) or (g).

34. A method of fabricating a plurality of patterned probes, the method comprising: (a) depositing a plurality of layers on a substrate that defines a horizontal surface, the plurality of layers comprising a silicon-containing film and a non-silicon bilayer resist developed on the silicon-containing film; (b) exposing the plurality of layers, thereby forming a pattern of at least one intermediary nanostructure; (c) depositing a hard mask layer on the plurality of layers; (d) performing a liftoff of portions of the hard mask layer, thereby forming a sample;2101715-001260 -28- (e) placing the sample into an coupled plasma (ICP) chamber; (f) flowing etching gas into the chamber, the etching gas comprising fluorine compound etching gas ; (g) etching portions of the sample to form the plurality of patterned probes on the substrate; and wherein each of the plurality of patterned probes includes a sidewall profile having a first portion between an attachment to the substrate and an inflection region, and a second portion between the inflection region and a distal end, wherein the first portion and the second portion have different profile characteristics.

35. The method of claim 34, wherein the respective distal ends of the plurality of patterned probes each has an apex diameter upper bound of less than 11 nm.

36. The method of claim 34, wherein step (f) comprises flowing the etching gas for a first duration, and step (g) comprises a first sub-step of forming the plurality of patterned probes having a tapered profile characteristic in at least the first portion of the sidewall profile.

37. The method of claim 36, wherein step (f) comprises flowing the etching gas for a second duration, and step (g) comprises a second sub-step of forming the second portion of the sidewall having a vertical profile characteristic in the second portion of the sidewall profile.

38. The method of claim 37, wherein the second sub-step is performed after the first sub-step and without distributing oxygen plasma within the ICP chamber in between performing the first sub-step and the second sub-step, and wherein the first duration is different from the second duration.

39. The method of claim 38, wherein the first duration is at least 4 min and the second duration is at least 2 min.

40. The method of claim 35, further comprising repeating the first sub-step and the second sub-step.

41. The method of claim 35, wherein the tapered first portion has a height of at least 500 nm.

42. The method of claim 34, wherein an in-plane width of the deposited hard-mask layer is in a range between 60 nm to 100 nm.

43. The method of claim 34, further comprising tuning the fabrication method to control one or more predetermined parameters of the plurality of patterned probes.

44. The method of claim 43, wherein the predetermined parameters comprise a distribution, a symmetry, a number, a sidewall angle, an apex radius, and an apex aspect ratio of the plurality of patterned probes.2101715-001260 -29- 45. The method of claim 34, wherein compound etching gas comprises trifluoromethane (CHF3), octafluorocyclobutane (C4F8), or a combination thereof.

46. An atomic force microscopy (AFM) cantilever comprising the plurality of patterned probes fabricated in accordance with the method of claim 1 or claim 34.

47. A scanning probe tip comprising the plurality of patterned probes fabricated in accordance with the method of claim 1 or claim 34.

48. A micro-mechanical spring with patterned probes system comprising: a plurality of conical patterned probes, each comprising a patterned probe fabricated in accordance with the method of claim 1 or claim 34; and a micro-mechanical spring.

49. The system of claim 48, wherein the micro-mechanical spring has a spring constant and a resonant frequency, each of which is tunable by modifying one of: a spring arm width, a number of spring arms, spacing between the number of spring arms, and a surface area coverage of a plurality of layers arranged in a stacking order, each layer having a pattern, a material, and a thickness.

50. The system of claim 48, wherein the plurality of conical patterned probes is coated with a thin film of material.

51. The system of claim 48, wherein the plurality of conical patterned probes is distributed such that respective distal ends of the plurality of conical patterned probes are arranged within a spot size of a laser or scanning device.

52. A method of fabricating a system comprising a micro-mechanical spring with a plurality of patterned probes, the method comprising: (a) fabricating the micro-mechanical spring by: (i) developing a patterned hard mask layer over a substrate, (ii) etching portions of the substrate for a duration, (iii) removing portions of the hard mask, (iv) removing silicon (Si) oxidation from the substrate, and (v) developing at least one patterned strain patch on the substrate, thereby forming a sample; (b) fabricating patterned probes by: (i) depositing one or more layers on the sample coating, (ii) depositing a hard mask layer on the one or more silicon-containing plurality of layers, thereby forming a second sample, (iii) placing the second sample into an inductively-coupled plasma (ICP) chamber,2101715-001260 -30- (iv) flowing etching gas ICP chamber, the etching gas comprising a trifluoromethane (CHF3) and octafluorocyclobutane (C4F8), (v) etching portions of the second sample to form at least one patterned probe; and (c) releasing the micro-mechanical spring.

53. The method of claim 52, wherein the patterned substrate hard mask layer over the substrate comprises chromium (Cr) hard mask over a silicon-on-insulator substrate.

54. The method of claim 52, wherein the hard mask comprises a Cr hard mask.

55. The method of claim 52, wherein the at least one patterned strain patch comprises a patterned Cr strain patch.

56. The method of claim 52, wherein depositing one or more layers on the sample coating comprises depositing one or more silicon-containing layers on the sample coating.

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