BR102012033304A2 - UNI-DIMENSION MASSIVE DEVICE FOR NEXT FIELD MICROSCOPY AND OPTICAL SPECTROSCOPY - Google Patents

Abstract

MASSIVE DEVICE WITH ONE-DIMENSIONAL END FOR MICROSCOPY AND OPTICAL FIELD SPECTROSCOPY NEARBY. The treated methane (Figure 1) is described by a massive device with one-dimensional end, for near-field microscopy and optical spectroscopy. This device comprises a massive probe, which can preferably be applied to microscopy and spectroscopy equipment and techniques, both by probe scanning. The proposed device (Figure 1) presents suitable dimensions for coupling with the electric field of light that preferably propagates in the normal direction to the surface to be analyzed. The treated material (Figure 1) is robust during the surface analysis process, being able to analyze nanometric dimensions structures with high resolution.

Description

“UNIDIMENSIONAL MASSIVE DEVICE FOR NEXT FIELD MICROSCOPY AND OPTICAL SPECTROSCOPY”

The treated matter (Figure 1) is described by a one-dimensional massive end device for near field optical microscopy and spectroscopy. This device comprises a massive probe, which can preferably be applied to microscopy and spectroscopy equipment and techniques, both by probe scanning. The proposed device (Figure 1) presents adequate dimensions for coupling with the electric field of Iuz that propagates preferentially in the normal direction to the surface to be analyzed. The treated material (Figure 1) presents robustness during the surface analysis process, being able to analyze with nanometer-sized structures with high resolution.

In the early 1980s, Scanning Probe Microscopy (SPM) surprised the world with the first atomic resolution images of the surface of a silicon crystal. Since then, the SPM technique has been widely used, producing images of atoms to nanometric structures on the surface of various materials. In precision manufacturing industries related to technologies such as microelectronics, solar energy, medical devices, automotive, aerospace and others, probe scanning microscopes allow users to monitor their products throughout the manufacturing process to improve productivity, reduce costs and improve product quality. The primary market for probe scanning microscopes is in the semiconductor and electronics sector, where they are routinely used for product inspection and fault analysis. They are also widely used in universities, research centers, and scientific centers around the world (Neves, B.R.A. et AL .. Ceramics, vol.44, n.290,1998).

SPM stands for a family of techniques that differ from each other by the type of probe-material interaction that is monitored in the process. Some examples are: AFM (atomic force microscopy; EFM (electrical force microscopy); MFM (magnetic force microscopy; STM (scanning tunneling microscopy); Near Field Optical Microscopy (SNOM) or Near Field Optical Microscopy (NFOM) In addition to microscopy information, several of these 5 techniques can provide spectroscopic information and are named by exchanging M by S is the acronym (example: STS instead of STM.) Although they provide very different information such as morphology, electrical conductivity, hardness, and magnetic and optical properties, all techniques in the SPM family are based on same principle of operation.Every 10 microscope operating the SPM techniques has at least one probe mechanical properties with the property required for the specific technique (electrical, magnetic, optical, etc.), a piezoelectric positioner capable of moving the probe with subnanometric precision, probe-sample interaction monitoring mechanism, preliminary probe positioning system 15 over the sample, system (s) of measurement of the effect of the specific technique used, and a computer that controls the entire system (Neves, BRA et AL .. Ceramics. vol.44, no. 290, 1998).

Microscopy and near field optical spectroscopy (SNOM or NFOM) is a hybrid of probe scanning microscopy with optical microscopy and spectroscopy (Synge, E.H. Phil. Mag. V.6, p.356, 1928). The probe, in this case, is the agent responsible for locating the optical signal primarily in a nanometric region, thus generating optical microscopy and spectroscopy with spatial resolution higher than the light diffraction limit. In one of its possible designs, this probe is formed of a very thin optical fiber that carries a light visible to the surface of the sample. As the excited area is of the order of the opening of the optical fiber, with the current technology it is possible to study the optical properties of materials with spatial resolution of the order of 50 nm (Neves et al. Ceramics, vol.44, n.290, 1998 ). The term “near field” comes from the fact that there are some components of the electromagnetic field that do not propagate through holes smaller than the wavelength of light due to the diffraction effect. However, at the probe opening there is a very intense “near field” that can be used for microscopy and spectroscopy using the SPM1 technique which is responsible for bringing the probe close enough to the surface (of the order of 1 nm) so that the near field may interact with the surface.

Depending on the size of the probe used in the process, the

Near field optical microscopy (SNOM) can better the spatial resolution obtained by a conventional optical instrument. With current technology, the SNOM technique can achieve a spatial resolution of the order of 10nm, which is well below the resolution of an atomic force or 10 tunnel microscope. However, SNOM brings several advantages originated from the SPM hybrid with microscopy and optical spectroscopy. Among the main parameters that may be of interest for the investigation of a nanoscale structure, in addition to shape and size, are its chemical composition, molecular structure, as well as its dynamic and electronic properties, widely measured by various optical properties. of materials.

Record resolution of 12nm was achieved not by using an optical fiber as a probe, but with the resonant effect of the propagating light with the plasmon of a metal probe (Hartschuh et al., Phys. Rev. Lett. 90, 2003). . As an example, the system may use the usual confocal configuration of an inverted optical microscope, with the light being condensed into a small 12nm region due to the resonance with the plasmons of a nanometer sized metal probe placed in the region to be studied by a light. SPM system. This effect enables effective measurements of low-intensity signals, such as Raman scattering on the nanometer scale, being called in this case TERS (T / p Enhanced Raman Spectroscopy, Chem. Phys. Lett. 335, 369-374 (2001)), in analogy to the well-known SERS (Surface Enhanced Raman Spectroscopy, see Chem. Phys. Lett. 126, 163, (1974)), which uses metal particles dispersed on a surface to increase the Raman signal by 30 molecules. The difference is that in the TERS configuration the position of this metal particle is controlled by an SPM type system. Nanoscopic spectroscopic images can be generated, and observation of Raman scattering and Iuz emission located in nanometric regions has been obtained by the technique (Maciel et al. Nature Materials, 7, 878 (2008)). Raman spectroscopy has wide application in the pharmaceutical, chemical and petroleum industries, with TERS having great potential to generate technological advances in these and other fields of activity.

The SNOM principle is relatively simple. The sample to be characterized is scanned by an optical fiber or a metal probe having an opening of the order of ten or tens of nanometers in diameter at its end. The fiber propagates visible light, which interacts with the sample, 10 and is then detected by a sensitive device or detector. With the metal probe, the propagating light is condensed in a nanometer region by the resonance effect with the surface plasmon of the metal. Another possibility is to cover an optical fiber with a metal film, thus taking advantage of the two technologies described above. 15 In all cases, the optical signal strength detected at each point of the scan constitutes a data set that will reproduce an image of the sample surface, with spatial resolution determined by the probe end size currently limited to 10 nm (Anderson, N. Hartschuh A., Novotny, L., J. Am. Chem. Soc. 127, 2533 (2005)).

The limitation imposed by the near field effect is that the distance between

the probe and sample must be in the order of a few nanometers. Thus, the probe is attached to a system capable of detecting the interaction of the probe with the surface, so that the probe is close enough to that surface that Van der Waals interactions can be felt. An example of a system capable of sensing this type of interaction is the piezoelectric oscillator, usually called a tuning fork (5, Figure 2), which is a tuning fork-like device with well-defined vibration frequency (Karrai K Grober, RD, Appi Phys. Lett. 66, 1842-1844 (1995)). When the probe attached to this device approaches the surface to be analyzed, the probe-surface interaction alters the pitch vibration frequency, and this variation is detected by system electronics. There are also other methods of measuring probe-surface interaction, such as reflecting a laser at the top of the probe, more common in AFM systems (Neves, B.R.A. et AL .. Ceramics, vol.44, n.290, 1998). Finally, with SNOM optical images are obtained from a sample which, for the purpose of data analysis, can be compared with topographic images acquired, for example, simultaneously with the atomic force method (LG Cançado, A. Hartschuh and L Novotny, J. Raman Spectrosc. 40, 1420-1426 (2009)).

There are, however, several limitations to the efficiency of an SNOM with respect to optical signal strength, both in the use of fiber optics (metallized or not) and metal probes.

In the case of the operation of near field optical microscopy

Using a fiber optic probe, one of the biggest limiters is the amount of light sent and / or collected that passes through this probe. The transmitted power decreases exponentially with the reduction in fiber diameter. For this reason, these systems have spatial resolution of the order of 50 to 15 100 nm. In addition to the problem of low resolution, the use of this type of probe is limited to the study of intense signals, such as photoluminescence. However, this method is unsuitable for the study of weaker signals, such as Ramanl spectroscopy where the signal strength is about a thousand times lower than luminescence signals, making Raman spectroscopy coupled with nanometric spatial resolution unviable.

In the case of the operation of near field microscopy using a metal probe, the material under study is illuminated by an optical microscope. A nanometer-sized metal tip is approximated to the sample by the SPM system, condensing the electric field 25 of the Iuz around it. In this technique, the resolution is in the order of 10 nm. This resolution is limited by the manufacturing technology of the metal probes, which will hardly evolve below 10 nm due to the metallurgical properties of the material used for their manufacture.

Improving the resolution of metal probes is not the only or the worst challenge: in all scanning probe microscopy the quality of the results is strongly related to the quality of the probe used. This fact has been the major limitation for the large-scale use of SNOM with metal probe. In fact, it is noted that most of the articles published in the field of near-field optical microscopy are related to the production and characterization of scanning devices / probes (Lambelet P., et al., Applied Optics, 37 (31), 7289-7292 (1998); Ren, B., Picardi G., Pettinger15 B., Rev. Sci Instrum 75, 837 (2004); Bharadwaj, P., Deutseh B., Novotny, L., Adv. Opt Photon 1,444-483 (2009)). What aggravates the probe quality problem for SNOM is that the coupling of these probes with the propagating light, which is responsible for the condensation of the field around the probe, is not simple, depending on the quality of the probe and the geometry of the 10-lumen system. probe. One of the reasons that the probe coupling with the Iuz is inefficient is that, as with any antenna, the electric field of polarization of the Iuz must be in the direction of the dipole axis, ideally at the antenna's leaving.

However, in the case of near field microscopy and spectroscopy 15 with the “zero-dimensional” probe ends, the nanoanthene axis is perpendicular to the surface. Thus, to illuminate the surface one has to use a direction of propagation of the light which, consequently, will have its electric field polarized normal to the surface, ie parallel to the axis of the antenna. For the implementation of this geometry, the so-called “doughnut mode”, 20 which generates a radial polarization propagating light, has been used (Quabis, S. et al. App. Phys. B: Laserand Optics, v.81, n.5 , p.597-600, 2005) This light, when focused by the microscope objective, generates a polarization component perpendicular to the lens focus surface, ie parallel to the nanoanthene axis.

In all processes used in microscopy and spectroscopy by

probe scanning, a probe is used that scans a surface for topographic, electrical, magnetic, elastic, optical, and other information. In order to obtain the best spatial resolution possible in this process of collecting surface information or objects on it (eg, adsorbed molecules), this probe should have as small an end (contacting the sample) as possible. Ideally, such an end would be a point which, for the surface, would represent a "zero" dimension material. This point or “zero-dimensional” probe is effectively formed by a single atom at the end of the probe as a whole, thus generating subatomic resolution images common in probe scan tunneling (STM) experiments.

5 Then a massive device is proposed, comprised of a probe

where the surface-probe interaction region is “one dimensional”. In this case, you have a one-dimensional element that scans a surface instead of a point. The probe is defined as having a "one-dimensional end", considering that the approaching end has one of its dimensions as small as possible and the other as elongated as necessary (Figure 1). This determines the importance of proposing a "One-dimensional massive end device (Figure 1) for near field optical microscopy and spectroscopy."

If, on the one hand, the one-dimensional system loses spatial resolution along one of its dimensions (Figure 1), when compared to one end, on the other, two important aspects are gained when applied to probe scanning microscopy and optical spectroscopy: ( 1) coupling with the excitation light is increased thereby increasing the efficiency of the optical effect; (2) mechanical strength is gained so that the spatial resolution in the other dimension 20 (Figure 1) can be reduced below the current technological limit of 10 nm.

Several patent applications describe microscopes for performing SNOM in detail, as found in JP2011122896A, entitled "Near-field optical microscope", and US6194711B1, entitled "Scanning near-field optical microscope".

Other documents focus specifically on probe properties

SNOM, addressing its operation and, in some cases, its manufacture. This can be seen in US4917462 entitled “Near field scanning optical microscopy”; US4604520, entitled "Optical nearfield scanning microscope"; US20100032719A1, entitled “Probes for Scanning 30 Probe Microscopy”; US007735147B2, entitled “Probe System Including an Electrical-Aligned Probe Tip and Method”; US20030094035A1, titled “Carbon Nanotube Probe Tip grown on a Small Probe”; US2004168527A1, titled “ Coated nanotube surface signal probe "; US20050083826A1, entitled Optical fiber probe using an electrical potential difference and an optical recorder using the same ”; US20080000293A1, entitled “Spm cantilever and manufacturing method thereof; W02009 / 085184A1, entitled “Protected 5 metallic tip or metallized scanning probe microscopy for optical applications”). In US005831743A entitled "Optical probes", for example, a new dual angle probe design is proposed. However, the objective is to measure Iuz fully reflected at the interface, unlike that proposed in the present invention.

There are also several documents claiming the use of

one-dimensional materials for applications such as SPM probes, as found in US007735147B2, entitled "Probe system comprising an electric-field-aligned probe tip and method for fabricating the same"; US20030094035A1 entitled “Carbon nanotube probe tip grown on a 15 small probe”; US2004168527A1, entitled “Coated nanotube surface signal probe”; and US20080000293A1, entitled “SPM Cantilever and Manufacturing Method Thereof. However, these documents deal with the device where the one-dimensional material is arranged perpendicular to the surface under study, so that the interaction with the surface is essentially "zero-dimensional".

It is found, therefore, that a solid one-dimensional end device for microscopy and near field optical spectroscopy as described in this invention is not described or claimed in any document.

In all cases described in the literature, the deficiency is in the

development of effective, robust probes with spatial resolution of less than tens of nanometers. The requirements are mechanical rigidity, optical efficiency and spatial resolution all together. The system must be rigid to serve also as a probe for atomic force microscopy, and must be coupled with the incident light's electromagnetic field, generating an increase in the nearby local field. This increase should be located in a region of space that currently, using metal probes or metalized optical fibers, is in the range of tens of nanometers.

The treated matter (Figure 1), in turn, can solve the aforementioned deficiencies, since it can present an electric dipole with direction (x 5 in Figure 2) and dimension suitable for coupling with the electric field of the Iuz that preferentially propagates. in the normal direction to the surface (z, Figure 2). The elongated structure in one direction (x in Figures 1 and 2) also provides mechanical rigidity to make the system more robust during the surface scanning process, and also to accommodate a nanometer-sized structure at reduced size ( y in Figure 2).

DESCRIPTION OF THE FIGURES

Figure 1 illustrates the one-dimensional device having a substantially cylindrical body (1) so that it has an extension represented by a faceted region (2) which in turn ends in a one-dimensional region (3); it is next to a substantially flat surface (4) to be analyzed.

Figure 2 illustrates the device (Figure 1) coupled to a probe-surface interaction sensing system or tuning fork (5).

Figure 3 illustrates the device (Figure 1) attached to a tuning fork or

tuning fork (5), so that the device (Figure 1) makes an angle (6) with the surface (4) by rotating along the xz plane.

Figure 4 illustrates the bottom view of the device (Figure 1), where the one-dimensional region (3) has a reduced dimension (7) and an elongated dimension (8).

Figure 5 shows two gallium ion scanning microscopy images of a one-dimensional solid device produced by chemical corrosion, followed by focused ion beam (FlB). In (a) one of the surfaces of the produced wedge is observed, while in (b) the angle of the wedge is seen in top view. Figure 6 shows a scanning electron microscopy image of another massive one-dimensional end device produced using Si as a form for metal deposition.

Figure 7 Schematically illustrates the device manufacturing process such that: (a) represents the sample after removal of the S1O2 or Si3N4 layer in specified regions; (b) represents the sample after anisotropic thinning; (c) represents the sample after metal deposition; (d) represents the sample after removal of the remainder of the S1O2 or Si3N4 layer (iift-out); (e) represents the process of removing the metal structure from the substrate; and (f) represents the device, object of this patent application, fit for use.

DETAILED DESCRIPTION OF THE INVENTION

The treated matter (Figure 1) comprises a one-dimensional solid-end device for near-field optical microscopy and spectroscopy, which has a substantially cylindrical (1) and solid body, so that it (1) has an extension represented by a region. faceted (2) preferably composed of gold (Au), silver (Ag) or copper (Cu), or combined together; which, in turn, ends in a one-dimensional region (3).

The device (Figure 1) is preferably used in equipment

and microscopy and spectroscopy techniques, both by probe scanning. The proposed device (Figure 1) has adequate dimensions for coupling with the electric field of Iuz that propagates preferentially in the normal direction to the surface to be analyzed.

The treated matter (Figure 1) can be coupled to a system of

sensing surface-probe interaction, preferably a piezoelectric oscillator (or tuning fork) (5), finally coupled, preferably in a SNOM system.

The present device or probe (Figure 1) can angle (6) to surface (4) by rotating along the xz, xy or yz planes (Figure 3). In fact, another important aspect that can be modulated is the angle that the one-dimensional end of the device makes to the surface. This aspect is illustrated in Figure 3, which shows an image of the piezoelectric oscillator (or tuning fork) (1) where the scanning probe (2) is attached, so that the one-dimensional end of the probe (3) makes an angle (5) with surface 5 (4). This angle allows modulating the coupling of the light with the probe and recovering the zero-dimensional condition of the scan. Probe-surface angulation can also be obtained in a number of ways. In the form shown in Figure 3, the probe can be fixed to the tuning fork at an angle. Alternatively, the probe may be aligned aligned with the tuning fork, and it has an angle to the surface. This second solution may be simpler to implement due to the size of the system. In any case, they are non-limiting descriptions. What is important is the angle between the one-dimensional end of the probe and the surface.

One-dimensional probes can be fabricated by the same methods used for fabricating conventional or zero-dimensional probes (BAF Puygranier, Dawson, P., 85, 235 (2000); Johnson, TW et al. ACS Nano 6 (10), 9168- 9174, (2012)), adapting only the geometry of the actions for roughing the material. Subsequently, it must be fixed to the sensory element of the probe-surface interaction that makes up the NSOM system.

The massive one-dimensional end device for near field optical microscopy and spectroscopy (Figure 1) is characterized by means of assessing the topography and optical properties of a surface.

The treated matter can be better understood through the

following non-limiting examples.

Example 1 - Manufacturing process of the one-dimensional solid device by chemical corrosion, followed by ion beam faceting.

The construction of a one-dimensional end device in

Nanoscale can initially be obtained by thinning the wire end using only a focused ion beam (FIB) device. However, the direct application of this technique may take an inevitably long time, compromising its applicability. To circumvent this difficulty, a fabrication process for the two-dimensional one-piece massive end device was performed. Initially an Au wire was radially corroded via electrochemical thinning forming a metal ferrule. In the second stage, the tip was taken to the FIB for later faceting, producing a one-dimensional device within the expected dimensions. This procedure aims to reduce the amount of material removed by the FIB to construct 10 (shape) the one-dimensional device. In this way we have reduced the time of operation in the FIB considerably, making it possible to make the massive one-dimensional end device in a few hours of operation (Figure 1).

The procedure for producing Au nanoparticles by electrochemical roughing is quick and simple (Ren, B. et al. Review of Scientific Instruments 75, 837-841 (2004)). An Au wire of 0.1 mm (99.99% purity) thickness was used as anode in an electrolyte cell. The cathode used was a ring made of tungsten wire with a diameter of approximately 6 mm. The ring was placed on the liquid electrolyte surface (light contact) used: a solution of hydrochloric acid (HCI) and Ethanol [1: 1]. The Au wire should be introduced concentric to the tungsten ring so that approximately 5 mm of it is submerged to the electrolyte. A stable direct current source should apply 2.4 V between the two electrodes, promoting concentric thinning of the anode (Au wire) that occurs preferentially at the liquid-metal-air interface. The good quality of the tapered end of the Au tip formed was not due to electrochemical roughing, but rather to mechanical breakage between the two parts. This rupture occurred within a period of less than 2 min after the electrode voltage was established. Shortly after disruption, the upper end, which carries the formed tip, was carefully washed with Ethanol to remove possible residues resulting from the electrochemical thinning reaction of gold, such as gold chloride (1), gold chloride (III) or acid. chloroauric (Quian, G et al. Review of Scientific Instruments 81, 016110 (2010)).

The tip of the nozzle was tuned with the use of submicron gallium ion beam in an FIB equipment. Firstly, a cut was made in the plane perpendicular to the axis of the wire in order to eliminate irregularities. Next, two other planes were cut in order to give the end a wedge shape. The gallium ion beam was also used to obtain images of the device (Figure 5), through the emission of secondary electrons. From the images, it can be concluded that at the end of the process, the end measured less than 5 micrometers in its elongated dimension.

Example 2 - Fabrication process of the one-dimensional solid mass device using Si as a form for metal deposition.

Cavities produced by anisotropic silicon roughing were used

as a way to produce the device. Due to the high control of the shape of these cavities, massive probes with one-dimensional tips of different sizes and apex less than 50 nm can be produced. Structures similar to this one, but shaped like pyramids with zero dimensional apex, were presented by several groups (Henzie, J. et al. Nano Ietters 5 (7), 1199-1202 (2005); Cui B., et al. Nanotechnology , 19 (14), 145302 (2008); Nagpal P., et al., Science 325, 594-597 (2009); Johnson, TW et al., ACS Nano 6 (10), 9168-9174 (2012)). In these works, properties such as roughness, apex radius and aspect ratio correspond to what is expected from a probe that has high efficiency, reproducibility and would lead to high spatial resolution images. In the work of Johnson (2012) (Johnson, T.W. et al. ACS nano 6 (10), 9168-9174 (2012)), the application of these pyramids in TERS and NSOM was demonstrated. The device claimed in the present application, in turn, had a different shape, that is, a one-dimensional end (Figure 6).

The manufacturing procedure of the object of the present invention (Figures 1 and 6) consisted of the use of an oxide (SiO2) or silicon nitride (Si3N4) coated single crystalline silicon (ννβίθή) blade as a starting material. The procedure removed areas of the SiO2 or Si3N4 layer, revealing the Si in those regions where anisotropic thinning later occurred (Figure 7 (a)). , rectangle or rod, with axes in the directions or coordinates (110) and (1-10) of the silicon blade.The difference between the largest and smallest dimensions ranged from 50nm to 10μηι, preferably 50nm.The described probes could still be produced. directing areas with exposed silicon out of the 10 mentioned directions and / or different shape, but the use of these three geometries in the proposed direction ionization of the one-dimensional apex of the probe, since this dimension is equal to the difference between the size of the rectangle, ellipse or rod axis. Silicon exposure in the determined areas was done in three different ways: using focused ion beam lithography (FIB) 15, electron beam lithography or conventional photolithography.

The second step was anisotropic thinning of exposed Si regions (Figure 7 (b)). To this end, the sample was immersed in a concentrated solution of NaOH or KOH in H2O and isopropyl alcohol, at temperatures ranging from 20 ° C to 95 ° C, preferably 80 ° C, for a period of time ranging from 30min to 300min, preferably 165min. The concentration of NaOH or KOH ranged from 2% to 45% w / w, but the best solution was NaOH or KOH (30% w / w) in H2O (60% w / w) and isopropyl alcohol (10% w / w). ).

Alternative solutions that could be used were: KOH in H2O; 25 NaOH in H 2 O; HF, HNO3 and CH3OOH; CsOH in H 2 O; NH 4 OH in H 2 O; TMAH in H2O; ethylenediamine in H 2 O and pyrocatechol; hydrazine in H2O and isopropyl alcohol. However, these solutions generated corrosion with reduced anisotropy or undesirable roughness in Si cavity walls, as found by Bean (1978) (Bean, KE, IEEE Transactions on 30 Electron Devices 25 (10), 1185-1193 (1978) ).

After this step, the sample was washed properly to remove corrosive agents. To do so, water was used first, preferably distilled, followed by a solution of H2SO4 and H2O2 (1: 1 w / w) and finally water again. The drying was done with nitrogen gas.

The third step comprised the deposition of the metal in the cavity (Figure 7 (c)). Gold was used because of its chemical stability and the fact that it was

Plasma energy is within the visible spectrum range, which has led to higher signal enhancement efficiency in NSOM and TERS. In addition, Au did not adhere to Si or SiO2, which facilitated the removal of Au structures from the cavity. However, other metals could generate probes that still showed signal increase when applied in NSOM or TERS, such as,

for example: Ag, Cu3Au, Cu and Al.

The deposition of the metal was made by sputtering (“thermal evaporation sputtering” or electrochemical deposition, with rates ranging from 0.05Å / s to 40 A / s, preferably 1 A / s. Among these metal deposition techniques, the Thermal evaporation was chosen.The metal layer had a final thickness between 50nm and 500nm, preferably 200nm.

The fourth step in the process is also called microfabrication lift-out. It comprised the removal of the silicon oxide or nitride layer (Figure 7 (d)). For this purpose, a concentrated solution (10% to 20 60%, preferably 49%) of hydrofluoric acid (HF) in H 2 O was used. The addition of uBuffered Hydrofluoric Acid '(BHF) led to the removal of the SiO2 or Si3N4 layer more slowly and in a controlled manner; leading to the same expected result. The sample was then washed with water. In order that the metal structures that remained inside the wells did not come out during washing, the sample was immersed in water for at least

2 minutes. Finally, the sample was dried. Thus, one-dimensional micrometric metal structures with one-dimensional extremity were inverted and coupled within the cavities (Figure 7 (d)).

Even if the metal of the structure has been coupled to Si, it can be easily uncoupled. For this purpose, a thin wire (ιμιτι at 100µm in diameter, preferably 15pm) was mounted on the side of a ituning fork piezoelectric oscillator used in techniques such as STM1 AFM, SNOM and TERS. A small amount of glue (preferably fast drying epoxy resin) was added to the apex of this wire and it was pressed onto one of the metal structures still located in the Si cavity (Figure 7 (e)). After drying the glue, the probe was removed in the normal direction to the surface. Thus, the one-dimensional end device was obtained at the end of a wire attached to one side of a tuning fork (Figure 6 and Figure 7 (f)); This device is then ready for use in techniques such as TERS and SNOM, for example.

Claims (7)

1. Massive one-dimensional end-device for near-field optical microscopy and spectroscopy, characterized in that it comprises a substantially cylindrical body (1) such that (1) has an extension represented by a faceted region (2) which in turn ends in a one-dimensional region (3), preferably composed of Au, Ag or Cu, or combined together; and (1) is coupled to a surface probe interaction sensing system (eg tuning fork oscillator or tuning fork) (5) and can rotate, when coupled to (5), along the xz, xy and yz planes with respect to the surface (4). Massive one-dimensional end device for near field optical microscopy and spectroscopy according to claim 1, characterized in that the dimensions of the one-dimensional region (3) can range from 1 angstrom to 50 nm in its reduced size (7 in Figure 4). , and from 1 nm to 5 prn in its elongated dimension (8 in Figure 4). Massive one-dimensional end device for near field optical microscopy and spectroscopy according to claims 1 and 2, characterized in that the entire device ((1), (2) and (3) in Figure 1) is composed of material preferably by Au, Ag or Cu, or combined together. Massive one-dimensional end device for near field optical microscopy and spectroscopy according to Claims 1 and 2, characterized in that the end of the device ((2) and (3) in Figure 1) is preferably coated with metallic material. by Au, Ag or Cu, or combined together. Massive one-dimensional end device for near field optical microscopy and spectroscopy according to Claims 1 and 2, characterized in that a one-dimensional element is coupled to the region (3), preferably a carbon nanotube or a nanotube beam. , or nanowire or nanobastom. Massive one-dimensional end device for near field optical microscopy and spectroscopy according to any of claims 1 to 5, characterized in that it can be used for near field optical microscopy and spectroscopy; preferably SNOM. Massive one-dimensional end device for near field optical microscopy and spectroscopy according to any one of claims 1 to 6, characterized in that it comprises means of assessing the topography and optical properties of a surface.