WO2012007602A1 - Method for manufacturing nanoneedles in areas of interest located inside solid samples on the nanometre scale - Google Patents

Method for manufacturing nanoneedles in areas of interest located inside solid samples on the nanometre scale Download PDF

Info

Publication number
WO2012007602A1
WO2012007602A1 PCT/ES2011/000180 ES2011000180W WO2012007602A1 WO 2012007602 A1 WO2012007602 A1 WO 2012007602A1 ES 2011000180 W ES2011000180 W ES 2011000180W WO 2012007602 A1 WO2012007602 A1 WO 2012007602A1
Authority
WO
WIPO (PCT)
Prior art keywords
nano
layer
manufacture
needles
areas
Prior art date
Application number
PCT/ES2011/000180
Other languages
Spanish (es)
French (fr)
Inventor
Sergio Ignacio Molina Rubio
Miriam Herrera Collado
Jesús HERNANDEZ SAZ
Original Assignee
Universidad De Cadiz
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Universidad De Cadiz filed Critical Universidad De Cadiz
Publication of WO2012007602A1 publication Critical patent/WO2012007602A1/en

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/30—Electron-beam or ion-beam tubes for localised treatment of objects
    • H01J37/305—Electron-beam or ion-beam tubes for localised treatment of objects for casting, melting, evaporating or etching
    • H01J37/3053—Electron-beam or ion-beam tubes for localised treatment of objects for casting, melting, evaporating or etching for evaporating or etching
    • H01J37/3056—Electron-beam or ion-beam tubes for localised treatment of objects for casting, melting, evaporating or etching for evaporating or etching for microworking, e.g. etching of gratings, trimming of electrical components
    • G—PHYSICS
    • G01—MEASURING; TESTING
    • G01N—INVESTIGATING OR ANALYSING MATERIALS BY DETERMINING THEIR CHEMICAL OR PHYSICAL PROPERTIES
    • G01N1/00—Sampling; Preparing specimens for investigation
    • G01N1/28—Preparing specimens for investigation including physical details of (bio-)chemical methods covered elsewhere, e.g. G01N33/50, C12Q
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J37/00—Discharge tubes with provision for introducing objects or material to be exposed to the discharge, e.g. for the purpose of examination or processing thereof
    • H01J37/26—Electron or ion microscopes; Electron or ion diffraction tubes
    • H01J37/28—Electron or ion microscopes; Electron or ion diffraction tubes with scanning beams
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2237/00—Discharge tubes exposing object to beam, e.g. for analysis treatment, etching, imaging
    • H01J2237/30—Electron or ion beam tubes for processing objects
    • H01J2237/317—Processing objects on a microscale
    • H01J2237/3174—Etching microareas
    • H01J2237/31745—Etching microareas for preparing specimen to be viewed in microscopes or analyzed in microanalysers
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01J—ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS
    • H01J2237/00—Discharge tubes exposing object to beam, e.g. for analysis treatment, etching, imaging
    • H01J2237/30—Electron or ion beam tubes for processing objects
    • H01J2237/317—Processing objects on a microscale
    • H01J2237/31749—Focused ion beam

Definitions

  • the invention is related to the manufacture of nano-needles in areas of interest located inside solid samples on a nanometric scale; specifically, it is related to the manufacture of nano-needles around particular areas of the sample using a focused ion beam, for different applications such as the analysis of certain areas of the sample by electron microscopy techniques such as electron tomography, or any other technique, or in general for applications where it is interesting to have a specific microstructural characteristic within a nano needle.
  • SNOM Near-Feld Scarming Optical Microscopy
  • UFM ultrasonic forced microscopy, ultrasonic force microscopy
  • nano-needles of different materials has a wide variety of applications, from sample preparation for analysis by transmission electron microscopy (TEM) or other techniques, to the manufacture of nano-needles for techniques such as near field scanning optical microscopy.
  • TEM transmission electron microscopy
  • the optimization of the electronic tomography requires a uniform thickness of the sample during the entire rotation range, as well as a geometry of the sample that allows the maximum degree of inclination; These requirements can only be achieved with needle-shaped samples. Because of this, in recent years there has been intensive research on how to manufacture these nano-needles, to optimize their characteristics for different applications.
  • electropolishing has traditionally been one of the main techniques for manufacturing nano-needles for some applications such as atomic probe microscopy (Melmed, AJ, The art and science and other aspects of making sharp tips. J. Vac. Sci. Technol. B 1991 , 9, (2), 601-608).
  • Other methods for manufacturing nano needles are based on selective chemical attack (Kim, Y. C; Seidman, DN, An electrochemical etching procedure for fabricating scanning tunneling microscopy and atom-probe feline-ion microscopy tips. Met. Mater.-lnt.
  • a manufacturing process is shown to obtain nano-needles at specific locations located inside a solid sample, using a commercial FIB equipped with a secondary electron detector.
  • the use of this method is exemplified by applying it to a sample of quantum dots of InAs / GaAs grown by the technique of gout epitaxy (Alonso-González, P .; Alen, B .; Fuster, D .; González, Y .; González , L .; Martinez-Pastor, J., Formation and optical characterization of single InAs quantum dots grown on GaAs nanoholes. Appl. Phys. Lett. 2007, 91, (16).
  • a method has been designed that encompasses preparation by FIB and observation by conventional TEM to find the location of the structural characteristic of interest and manufacture a nano-needle exactly in that position.
  • the relative simplicity of this method makes it possible to apply to a wide variety of structural characteristics in different materials, allowing the manufacture of nano-needles in specific areas for a wide variety of applications.
  • Sample preparation in the form of nano-needles is important, among other applications, because it allows the study of independent characteristics of a material through characterization techniques such as electron tomography, atomic probe microscopy, etc.
  • nano-needles are the best sample design to meet the requirements of fixed sample thickness in the rotation range, etc.
  • Some nano-needle manufacturing methods such as chemical attack are not specific to the specific area where the needle is to be manufactured, so they have limited applications.
  • Sample preparation using a focused ion beam has the main advantage that the area of interest can be selected with a precision of the order of nanometers on the surface of the sample. However, for many studies the area of interest is located inside the sample, so they are not visible from its surface.
  • the invention presented provides a method for the preparation of nano-needles in specific areas on the nanometer scale located inside the sample, by using a beam of localized ions.
  • a series of marks are introduced on the surface of a layer of material previously thinned to electron transparency, allowing the location of the area of interest by locating said marks for the subsequent step of manufacturing the needle.
  • This method comprises the deposition of a protective layer (of polymer or metal, etc.) on the surface of the sample, and the removal of the material located on both sides of this protective layer by ionic attack to leave a thin layer of material. Subsequently, this layer of material is taken to a TEM grid with a micromanipulator, where it is thinned to electron transparency by ionic attack. Most of the characteristics of the microstructure of a material are not observable with the FIB secondary electron detector and need to be located in a TEM.
  • the method comprises the introduction of marks on the surface of the material layer, and the observation of said layer by TEM to find the position of the area of interest with respect to the marks introduced.
  • the surface of the protective layer is marked just above the area of interest, and the nano needle is manufactured by ionic attack just at that surface mark.
  • it can be done by observing the nano needle for a certain time with a beam of low-voltage ions.
  • Figure LA - Representation of the protective layer on the surface of the sample.
  • Figure I.D. - Material layer attached to both the micromanipulator and the TEM grid.
  • Figure 2.B Representation of the ion beam during the attack to make a nano needle.
  • Figure 3.A - Material layer with mark on the surface of the protective layer, just above the area of interest.
  • Figure 4. Image of TEM in dark field conditions 002 of an InAs / GaAs QD in a marked sheet.
  • the method for manufacturing nano-needles in localized areas proposed in this patent requires a thin layer of electron-transparent material attached to a TEM grid.
  • the use of the FIB is the most appropriate option since it is precise, fast and reliable, and can be applied to a wide variety of different materials.
  • the classical methods are the H-bar technique (Li, J .; Malis, T .; Dionne, S., Recent advances in FIB-TEM specimen preparation techniques. Mater. Charact.
  • the ion beam acceleration voltage it will be in the 5kV-30V range, being a beam of Ga ions, Au ions, Ar ions, Li ions, and Be ions, He ions or Au-Si-Be ions, and the current is the range 1 ⁇ -20 ⁇ .
  • Fig. 1a-d schematically shows the manufacturing process of an electron-transparent layer of material by means of the in-situ lift-out method.
  • Fig. 1.a shows a protective layer (1) deposited on the surface of the sample (2); Normally, the protective layer is a metal layer deposited with the help of the electron or ion beam by vapor deposition (CVD), although it can be made of other materials such as C, polymers, etc.
  • Fig. 1.b shows the result of removing material (3) on both sides of the protective layer (2) by attack with the ion beam; in this way, a layer of material about 2 ⁇ thick should remain.
  • Fig. 1.c shows the micromanipulator (4) that joins the thin layer of material (5); said layer must be separated from the sample by cutting along the dotted line (6) and taken to the TEM grid (7), as shown in Fig. l.d.
  • the joining of the thin layer of material to the micromanipulator or to the grid is produced by depositing a layer of material (8) between them (it can be the same material as the protective layer), and the separation of said layer from the starting material or the micromanipulator It is carried out by ionic attack along the dotted line (6) in the figures.
  • the layer of material is attached to the TEM grid, it must be thinned to electron transparency.
  • the final thickness of the layer in this step must reach a compromise: it must be electronically transparent, since the position of the area of interest must be observable by TEM. However, it should not be too thin, as this would make it too weak for subsequent steps to mark the surface of the layer and fabricate the nano needle.
  • the final thickness should be chosen according to the nature of the sample material (in general, it should be in the range 20- 350 nm), but a good approximation would be a value between 150 and 250 nm.
  • the ion beam current must be as small as possible while maintaining a reasonable attack time, to obtain good attack accuracy. You should try to keep as much of the protective layer as possible during the attack, for which it is very useful to follow the attack process by observing with the electron beam.
  • the sample would be ready to be observed in TEM and find the position of the area of interest, but do not forget that the position of this area must be recognizable later in the FIB to be able to manufacture the nano needle exactly in that position (a large part of the characteristics of interest of a solid are not visible with the secondary electron detector of the FIB).
  • Fig. 2.a shows an electron-transparent layer (6) covered by a protective layer (2) where some marks (10) have been introduced with the ion beam to locate the area of interest with respect to said marks. Once the layer is marked, it can be observed in the TEM to find the position of the area of interest with respect to the marks, and then it will be taken back to the FIB to manufacture the nano-needles.
  • Fig. 2.b shows a scheme of the application of the AMM to manufacture a nano-needle (11), where the ion beam (12) attacks the surface of the protective layer (8) according to a ring-shaped pattern with a diameter interior and exterior determined.
  • the relative position of the marks must be taken into account. The marks are only visible with the ion beam when the sample is observed in cross-section, however the nano-needle is manufactured by ionic attack from the upper surface of the protective layer, as shown in Fig. 2.b.
  • Fig. 3.a shows a cross-sectional view of the layer showing the position of the new mark (13) on the upper surface of the protective layer (8)
  • Fig. 3.b shows a view of the part upper of the protective layer (8) with the new mark (13), as would be observed just before starting the ionic attack to make the nano-needle.
  • a nano-needle can be manufactured by ionic attack, using an annular pattern of progressively smaller diameter, and choosing a series of suitable currents depending on the nature of the material but trying to keep them as small as possible to achieve sufficient precision to manufacture a nano-needle of reduced diameter.
  • the methodology for the manufacture of nano-needles in specific areas on a nanometric scale located below the surface of the sample can be applied to the sample preparation for electronic tomography of samples of epitaxial structures of InD QDs grown on GaAs substrates, in samples where The density of QDs is very low.
  • the first step of the method is to protect the surface of the sample and then remove material by ionic attack until it forms a thin layer that will be taken to a TEM grid.
  • an initial Pt deposition produced with the electron beam for half an hour (15kV, 2nA) is sufficient to reinforce the surface of the sample before the deposition of Pt by the ion beam (30kV, 0.3 nA).
  • this layer of Pt should have a thickness of about 2 ⁇ , a width between 1 and 3 ⁇ , and the length can vary between approximately 2 and 20 ⁇ (normally we deposit a layer of about 10-15 ⁇ ).
  • the material layer of final interest should be about 2 ⁇ thick.
  • 7nA currents are used up to a distance of 4 ⁇ from the Pt layer, and from there on InA.
  • the material layer is carried from the sample to the TEM grid with a micromanipulator.
  • the joining of the GaAs layer to the micromanipulator or to the TEM grid is done by depositing C with a current of O.lnA, while the separation of said layer from the sample or the micromanipulator, by ionic attack on O.lnA.
  • the material layer is thinned to electron transparency.
  • the final thickness of the layer must reach a compromise since it must be transparent to the electrons but it should not be too thin as this would make it too weak for subsequent steps to mark the surface of the layer.
  • a final thickness of 250nm is acceptable.
  • the current for this thinning process must be reduced sequentially to improve the accuracy of the chemical attack while optimizing the duration of the process.
  • O.lnA can be used until the layer of material measures approximately 400nm thick, and 0.05nm until it measures about 250nm.
  • the next step in the method of this patent is to mark the layer of material and take it to the TEM, to observe the position of the QDs and to be able to locate them in the FIB taking as reference the introduced marks.
  • These marks must meet the requirements mentioned above.
  • the marks have been designed as a line of circles engraved on the surface of the layer with the ion beam, with a diameter of 50nm and depth of ⁇ 50nm, whose centers are separated about 150nm.
  • These marks are recorded in the GaAs layer located above the InAs points, since if they were recorded in the Pt layer, which would be safer for the sample, they are not well observed in the TEM.
  • the material layer has a maximum length of 3 ⁇ , otherwise an excessive number of marks in the layer would make it difficult to locate the QDs in the FIB. If the layer of original material is longer than 3 ⁇ , it can be cut into smaller layers when carried to the TEM grid. Once the layer is marked, it can be observed in TEM.
  • Fig. 4 shows a TEM image of the sample marked in conditions 002 in a dark field, where one of the InAs points is included.
  • the new brand is a cylinder of 50-100nm diameter and 250nm depth just on the surface of the Pt.
  • the new brand will be used to locate the position where the nano-needle will be manufactured.
  • the ion beam must be attacked at a reduced voltage of 20kV. This is usually carried out in two steps, the first to a diameter of 200nm, and the second to the final diameter of the nano needle.
  • the surface quality of the nano-needle can be improved by observing the nano-needle at 5kV for a few minutes ( ⁇ 30min, depending on the magnification), to reduce the thickness of the surface amorphous layer.

Landscapes

  • Chemical & Material Sciences (AREA)
  • Analytical Chemistry (AREA)
  • Physics & Mathematics (AREA)
  • Health & Medical Sciences (AREA)
  • Life Sciences & Earth Sciences (AREA)
  • Biochemistry (AREA)
  • General Health & Medical Sciences (AREA)
  • General Physics & Mathematics (AREA)
  • Immunology (AREA)
  • Pathology (AREA)
  • Engineering & Computer Science (AREA)
  • Plasma & Fusion (AREA)
  • Sampling And Sample Adjustment (AREA)
  • Analysing Materials By The Use Of Radiation (AREA)

Abstract

The invention relates to a method for manufacturing nanoneedles in areas of interest located inside solid samples on the nanometre scale. The method relates to FIB sample preparation for analysis of said sample using any technique, in which it is interesting to study an independent feature of the material, or where it is useful to have a specific feature in a nanoneedle such as for the production of SNOM nanoneedles. FIB sample preparation enables the selection of specific features of the surface of the sample on the nanometre scale, but when the area of interest is located inside a solid sample, a novel method is required. Said method is disclosed in the present invention, combining production by FIB - including the addition of marks on a layer of electron-transparent material - with TEM observation in order to select a specific feature of the inside of the material and to manufacture a nanoneedle using said feature.

Description

MÉTODO PARA FABRICAR NANOAGUJAS EN ZONAS DE INTERÉS LOCALIZADAS EN EL INTERIOR DE MUESTRAS SÓLIDAS A ESCALA NANOMÉTRICA.  METHOD FOR MANUFACTURING NANOAGUJAS IN AREAS OF INTEREST LOCATED INSIDE SOLID SAMPLES AT NANOMETRIC SCALE.
SECTOR DE LA TÉCNICA. SECTOR OF THE TECHNIQUE.
La invención está relacionada con la fabricación de nanoagujas en zonas de interés localizadas en el interior de muestras sólidas a escala nanométrica; en concreto, está relacionada con la fabricación de nanoagujas alrededor de zonas particulares de la muestra usando un haz de iones focalizado, para diferentes aplicaciones como el análisis de ciertas zonas de la muestra por técnicas de microscopía electrónica como tomografía electrónica, o cualquiera otra técnica, o en general para aplicaciones donde es interesante tener una característica microestructural concreta dentro de una nanoaguja. Por ejemplo, para la fabricación de nanoagujas SNOM (Near-fíeld scarming optical microscopy, microscopía óptica de barrido de campo cercano) con propiedades ópticas controladas y determinadas por una características particular localizada en la nanoaguja, o para nanoagujas para otras técnicas como UFM (ultrasonic forcé microscopy, microscopía de fuerza ultrasónica). Por lo tanto, se puede englobar en el campo de la Nanotecnología. The invention is related to the manufacture of nano-needles in areas of interest located inside solid samples on a nanometric scale; specifically, it is related to the manufacture of nano-needles around particular areas of the sample using a focused ion beam, for different applications such as the analysis of certain areas of the sample by electron microscopy techniques such as electron tomography, or any other technique, or in general for applications where it is interesting to have a specific microstructural characteristic within a nano needle. For example, for the manufacture of SNOM (Near-Feld Scarming Optical Microscopy) with controlled optical properties and determined by a particular characteristic located in the nano-needle, or for nano-needles for other techniques such as UFM (ultrasonic forced microscopy, ultrasonic force microscopy). Therefore, it can be included in the field of Nanotechnology.
ESTADO DE LA TÉCNICA. STATE OF THE TECHNIQUE.
La fabricación de nanoagujas de distintos materiales tiene una gran variedad de aplicaciones, desde la preparación de muestra para análisis por microscopía electrónica de transmisión (TEM) u otras técnicas, hasta la fabricación de nanoagujas para técnicas como microscopía óptica de barrido de campo cercano. Por ejemplo, la optimización de la tomografía electrónica requiere un espesor uniforme de la muestra durante todo el rango de giro, así como una geometría de la muestra que permita el máximo grado de inclinación; estos requerimientos sólo se pueden conseguir con muestras en forma de aguja. Debido a esto, en los últimos años ha habido una investigación intensiva en la forma de fabricar estas nanoagujas, para optimizar sus características para distintas aplicaciones. Así, tradicionalmente el electropulido ha sido una de las principales técnicas para fabricar nanoagujas para algunas aplicaciones como microscopía de sonda atómica (Melmed, A. J., The art and science and other aspects of making sharp tips. J. Vac. Sci. Technol. B 1991, 9, (2), 601-608). Otros métodos para fabricar nanoagujas están basados en ataque químico selectivo (Kim, Y. C; Seidman, D. N., An electrochemical etching procedure for fabricating scanning tunneling microscopy and atom-probe fíeld-ion microscopy tips. Met. Mater.-lnt. 2003, 9, (4), 399-404), a veces aplicado tras litografía (Larson, D. J.; Wissman, B. D.; Martens, R. L.; Viellieux, R. J.; Kelly, T. F.; Gribb, T. T.; Erskine, H. F.; Tabat, N., Advances in atom probé specimen fabrication from planar multilayer thin film structures. Microsc. microanal. 2001, 7, (1), 24-31) o tras el corte mecánico de la muestra (Morris, R. A.; Martens, R. L.; Zana, I.; Thompson, G. B., Fabrication of high-aspect ratio Si pillars for atom probé 'lift-out' and field ionization tips. Ultramicroscopy 2009, 109, (5), 492-496). Se han propuesto otros métodos más específicos para fabricar nanoagujas con propiedades magnéticas definidas para microscopía de barrido de fuerza magnética, basada en la descomposición selectiva de compuestos orgánicos volátiles por medio de un haz de iones focalizado (US Patent Number 5,171,992), o para agujas para microscopía de fuerza atómica, basados en ataque químico (US Patent Number 6,457,350 Bl y 5,611,942). Además, se han usado métodos basados en el ataque con un haz de iones para fabricar agujas con una apertura para su uso en microscopía óptica de barrido de campo cercano (US Patent Number 6,633,711 Bl), para agujas para microscopía de barrido de sonda o incluso para fabricar filamentos de emisión de electrones (US Patent Number 5,727,978). The manufacture of nano-needles of different materials has a wide variety of applications, from sample preparation for analysis by transmission electron microscopy (TEM) or other techniques, to the manufacture of nano-needles for techniques such as near field scanning optical microscopy. For example, the optimization of the electronic tomography requires a uniform thickness of the sample during the entire rotation range, as well as a geometry of the sample that allows the maximum degree of inclination; These requirements can only be achieved with needle-shaped samples. Because of this, in recent years there has been intensive research on how to manufacture these nano-needles, to optimize their characteristics for different applications. Thus, electropolishing has traditionally been one of the main techniques for manufacturing nano-needles for some applications such as atomic probe microscopy (Melmed, AJ, The art and science and other aspects of making sharp tips. J. Vac. Sci. Technol. B 1991 , 9, (2), 601-608). Other methods for manufacturing nano needles are based on selective chemical attack (Kim, Y. C; Seidman, DN, An electrochemical etching procedure for fabricating scanning tunneling microscopy and atom-probe feline-ion microscopy tips. Met. Mater.-lnt. 2003, 9, (4), 399-404), sometimes applied after lithography (Larson, DJ; Wissman, BD; Martens, RL; Viellieux, RJ; Kelly, TF; Gribb, TT; Erskine, HF; Tabat, N., Advances in atom I tried specimen fabrication from planar multilayer thin film structures, microanal microsc. 2001, 7, (1), 24-31) or after the mechanical cutting of the sample (Morris, RA; Martens, RL; Zana, I. ; Thompson, GB, Fabrication of high-aspect ratio If pillars for atom tried 'lift-out' and field ionization tips, Ultramicroscopy 2009, 109, (5), 492-496). Other more specific methods have been proposed to manufacture nano-needles with defined magnetic properties for magnetic force scanning microscopy, based on the selective decomposition of volatile organic compounds by means of a focused ion beam (US Patent Number 5,171,992), or for needles for atomic force microscopy, based on chemical attack (US Patent Number 6,457,350 Bl and 5,611,942). In addition, methods based on ion beam attack have been used to make needles with an aperture for use in near-field scanning optical microscopy (US Patent Number 6,633,711 Bl), for needles for probe scanning microscopy or even to manufacture electron emission filaments (US Patent Number 5,727,978).
El uso de métodos basados en ataque con haces de iones focalizados con un sistema de barrido de doble haz (haz de iones focalizados y haz de electrones) al que llamaremos FIB a partir de ahora ha demostrado ser una forma rápida y fiable de fabricar nanoagujas de una gran variedad de materiales (Miller, M. K.; Russell, K. F.; Thompson, G. B., Strategies for fabricating atom probé specimens with a dual beam FIB. Ultramicroscopy 2005, 102, (4), 287-298;Thompson, K.; Lawrence, D.; Larson, D. J.; Olson, J. D.; Kelly, T. F.; Gorman, B., In situ site-specific specimen preparation for atom probé tomography. Ultramicroscopy 2007, 107, (2-3), 131-139). La forma más extendida de fabricar nanoagujas consiste en atacar la muestra sólida con un patrón en forma de anillo con diámetro variable (el llamado Annular Milling Method, AMM) (Miller, M. K.; Russell, K. F.; Thompson, G. B., Strategies for fabricating atom probé specimens with a dual beam FIB. Ultramicroscopy 2005, 102, (4), 287-298;Larson, D. J.; Foord, D. T.; Petford-Long, A. .; Liew, H.; Blamire, M. G.; Cerezo, A.; Smith, G. D. W. In Field-ion specimen preparation using focused ion-beam milling, Irbid, Jordán, Sep 12-18, 1998; Elsevier Science Bv: Irbid, Jordán, 1998; pp 287-293). Sin embargo, se han propuesto otras formas de fabricar nanoagujas con el FIB, como cortar un hilo horizontal de la superficie de la muestra y llevarlo a una rejilla (Saxey, D. W.; Cairney, J. M.; McGrouther, D.; Honma, T.; Ringer, S. P., Atom probé specimen fabrication methods using a dual FIB/SEM. Ultramicroscopy 2007, 107, (9), 756-760), o el método cut-out, donde a una lámina adelgazada se le cortan ambos lados dejando un pillar de reducido tamaño en medio (Saxey, D. W.; Cairney, J. M.; McGrouther, D.; Honma, T.; Ringer, S. P., Atom probé specimen fabrication methods using a dual FIB/SEM. Ultramicroscopy 2007, 107, (9), 756-760). La principal ventaja de la fabricación de nanoagujas por FIB consiste en que la zona de interés donde se fabricará la aguja puede ser seleccionada de la superficie de la muestra con una precisión del orden del nanómetro, lo cual no se puede conseguir con otras técnicas como electropulido. Sin embargo, cuando la zona de interés necesita ser seleccionada de características estructurales localizadas en el interior de la muestra sólida (y la mayoría de las veces estas características estructurales no son visibles con el detector de electrones secundarios del FIB incluso aunque estuvieran en la superficie) la preparación presenta complicaciones adicionales, y hasta el momento, sólo algunos avances en la instrumentación utilizada ha permitido superar esta dificultad. Por ejemplo, la observación de puntos cuánticos de InAs desde varias direcciones fabricando un pilar que incluya uno de esos puntos cuánticos ha sido posible usando un microscopio electrónico equipado con un sistema FIB, donde es posible hacer el ataque iónico in-situ (Inoue, T.; ita, T.; Wada, O.; Konno, M.; Yaguchi, T.; Kamino, T.; Ieee, Multidirectional transmission electrón microscope observation of a single InAs/GaAs self-assembled quantum dot. In 2007 International Conference on Indium Phosphide and Related Materials, Conference Proceedings, Ieee: New York, 2007; pp 579-581). Se han publicado otros estudios relacionados con la preparación de muestra en zonas de la muestra localizadas debajo de su superficie, como el análisis de bordes de grano (Pérez- Willard, F.; Wolde-Giorgis, D.; Al- Kassab, T.; López, G. A.; Mittemeijer, E. J.; Kirchheim, R.; Gerthsen, D., Focused ion beam preparation of atom probé specimens containing a single crystallographically well-defined grain boundary. Micron 2008, 39, (1), 45-52) o de grietas de corrosión por estrés (Lozano- Perez, S., A guide on FIB preparation of samples containing stress corrosión crack tips for TEM and atom-probe analysis. Micron 2008, 39, (3), 320-328), pero en estos casos el defecto o ya es visible con el detector de electrones secundarios porque alcanza la superficie de la muestra, o se puede hacer visible en la superficie mediante ataque químico o pulido. The use of methods based on attack with focused ion beams with a double beam scanning system (focused ion beam and electron beam) which we will call FIB from now on has proven to be a fast and reliable way to manufacture nano-needles a wide variety of materials (Miller, MK; Russell, KF; Thompson, GB, Strategies for fabricating atom tested specimens with a dual beam FIB. Ultramicroscopy 2005, 102, (4), 287-298; Thompson, K .; Lawrence, D .; Larson, DJ; Olson, JD; Kelly, TF; Gorman, B., On-site site-specific specimen preparation for atom test tomography, Ultramicroscopy 2007, 107, (2-3), 131-139). The most widespread way to make nano-needles is to attack the solid sample with a ring-shaped pattern with variable diameter (the so-called Annular Milling Method, AMM) (Miller, MK; Russell, KF; Thompson, GB, Strategies for fabricating atom I tried specimens with a dual beam FIB. Ultramicroscopy 2005, 102, (4), 287-298; Larson, DJ; Foord, DT; Petford-Long, A. .; Liew, H .; Blamire, MG; Cherry, A .; Smith, GDW In Field-ion specimen preparation using focused ion-beam milling, Irbid, Jordan, Sep 12-18, 1998; Elsevier Science Bv: Irbid, Jordan, 1998; pp 287-293). However, other ways of manufacturing nano-needles with the FIB have been proposed, such as cutting a horizontal wire from the surface of the sample and bringing it to a rack (Saxey, DW; Cairney, JM; McGrouther, D .; Honma, T .; Ringer, SP, Atom tried specimen fabrication methods using a dual FIB / SEM, Ultramicroscopy 2007, 107, (9), 756-760), or the cut-out method, where a thinned sheet is cut on both sides leaving a catch small in size (Saxey, DW; Cairney, JM; McGrouther, D .; Honma, T .; Ringer, SP, Atom tested specimen fabrication methods using a dual FIB / SEM. Ultramicroscopy 2007, 107, (9), 756 -760). The main advantage of the manufacture of nano-needles by FIB is that the area of interest where the needle will be manufactured can be selected from the surface of the sample with a precision of the order of the nanometer, which cannot be achieved with other techniques such as electropolishing . However, when the area of interest needs to be selected from structural features located inside the solid sample (and most often these structural features are not visible with the FIB secondary electron detector even if they were on the surface) The preparation presents additional complications, and so far, only some progress in the instrumentation used has overcome this difficulty. For example, the observation of InAs quantum dots from several directions by fabricating a pillar that includes one of those quantum dots has been possible using an electron microscope equipped with an FIB system, where it is possible to do the in-situ ionic attack (Inoue, T .; ita, T .; Wada, O .; Konno, M .; Yaguchi, T .; Kamino, T .; Ieee, Multidirectional transmission electron microscope observation of a single InAs / GaAs self-assembled quantum dot. In 2007 International Conference on Indium Phosphide and Related Materials, Conference Proceedings, Ieee: New York, 2007; pp 579-581). Other studies related to sample preparation have been published in areas of the sample located below its surface, such as grain edge analysis (Pérez-Willard, F .; Wolde-Giorgis, D .; Al-Kassab, T. ; López, GA; Mittemeijer, EJ; Kirchheim, R .; Gerthsen, D., Focused ion beam preparation of atom probé specimens containing a single crystallographically well-defined grain boundary. Micron 2008, 39, (1), 45-52) or stress corrosion cracks (Lozano-Perez, S., A guide on FIB preparation of samples containing stress corrosion crack tips for TEM and atom-probe analysis. Micron 2008, 39, (3), 320-328), but in these cases the defect or is already visible with the secondary electron detector because it reaches the surface of the sample, or it can be made visible on the surface by chemical attack or polishing.
En la presente invención, se muestra un proceso de fabricación para obtener nanoagujas en lugares específicos localizados en el interior de una muestra sólida, usando un FIB comercial equipado con un detector de electrones secundarios. La utilización de este método se ejemplifica aplicándolo a una muestra de puntos cuánticos de InAs/GaAs crecida por la técnica de epitaxia de gota (Alonso-González, P.; Alen, B.; Fuster, D.; González, Y.; González, L.; Martinez-Pastor, J., Formation and optical characterization of single InAs quantum dots grown on GaAs nanoholes. Appl. Phys. Lett. 2007, 91, (16). Se ha diseñado un método que engloba preparación por FIB y observación mediante TEM convencional para encontrar la localización de la característica estructural de interés y fabricar una nanoaguja exactamente en esa posición. La relativa simplicidad de este método hace que se pueda aplicar a una gran variedad de características estructurales en diferentes materiales, permitiendo la fabricación de nanoagujas en zonas concretas para una gran diversidad de aplicaciones. In the present invention, a manufacturing process is shown to obtain nano-needles at specific locations located inside a solid sample, using a commercial FIB equipped with a secondary electron detector. The use of this method is exemplified by applying it to a sample of quantum dots of InAs / GaAs grown by the technique of gout epitaxy (Alonso-González, P .; Alen, B .; Fuster, D .; González, Y .; González , L .; Martinez-Pastor, J., Formation and optical characterization of single InAs quantum dots grown on GaAs nanoholes. Appl. Phys. Lett. 2007, 91, (16). A method has been designed that encompasses preparation by FIB and observation by conventional TEM to find the location of the structural characteristic of interest and manufacture a nano-needle exactly in that position.The relative simplicity of this method makes it possible to apply to a wide variety of structural characteristics in different materials, allowing the manufacture of nano-needles in specific areas for a wide variety of applications.
DESCRIPCIÓN DE LA INVENCIÓN Breve descripción de la invención DESCRIPTION OF THE INVENTION Brief description of the invention
La preparación de muestra en la forma de nanoagujas es importante, entre otras aplicaciones, porque permite el estudio de características independientes de un material mediante técnicas de caracterización como tomografía electrónica, microscopía de sonda atómica, etc. Para tomografía electrónica, las nanoagujas constituyen el mejor diseño de la muestra para cumplir los requerimientos de espesor de muestra fijo en el rango de giro, etc. Algunos métodos de fabricación de nanoagujas como ataque químico no son específicos respecto a la zona concreta donde se quiere fabricar la aguja, por lo que tienen aplicaciones limitadas. La preparación de muestra usando un haz de iones focalizados, por otro lado, tiene como ventaja principal que el área de interés se puede seleccionar con una precisión del orden de nanómetros en la superficie de la muestra. Sin embargo, para muchos estudios la zona de interés está localizada en el interior de la muestra, por lo que no son visibles desde la superficie de ésta. Sample preparation in the form of nano-needles is important, among other applications, because it allows the study of independent characteristics of a material through characterization techniques such as electron tomography, atomic probe microscopy, etc. For electronic tomography, nano-needles are the best sample design to meet the requirements of fixed sample thickness in the rotation range, etc. Some nano-needle manufacturing methods such as chemical attack are not specific to the specific area where the needle is to be manufactured, so they have limited applications. Sample preparation using a focused ion beam, on the other hand, has the main advantage that the area of interest can be selected with a precision of the order of nanometers on the surface of the sample. However, for many studies the area of interest is located inside the sample, so they are not visible from its surface.
La invención que se presenta proporciona un método para la preparación de nanoagujas en zonas concretas en la escala del nanómetro localizadas en el interior de la muestra, mediante el uso de un haz de iones localizados. En este método, se introducen una serie de marcas en la superficie de una capa de material previamente adelgazada hasta electrón-transparencia, permitiendo la localización de la zona de interés mediante la localización de dichas marcas para el posterior paso de fabricar la aguja. The invention presented provides a method for the preparation of nano-needles in specific areas on the nanometer scale located inside the sample, by using a beam of localized ions. In this method, a series of marks are introduced on the surface of a layer of material previously thinned to electron transparency, allowing the location of the area of interest by locating said marks for the subsequent step of manufacturing the needle.
Este método comprende la deposición de una capa protectora (de polímero o metal, etc.) en la superficie de la muestra, y la eliminación del material localizado a ambos lados de esta capa protectora mediante ataque iónico para dejar una fina capa de material. Posteriormente, esta capa de material se lleva a una rejilla de TEM con un micromanipulador, donde se adelgaza hasta electrón-transparencia por ataque iónico. La mayoría de las características de la microestructura de un material no son observables con el detector de electrones secundarios del FIB y necesitan ser localizadas en un TEM. Así, el método comprende la introducción de unas marcas en la superficie de la capa de material, y la observación de dicha capa por TEM para encontrar la posición de la zona de interés con respecto a las marcas introducidas. Tras esto, se marca la superficie de la capa protectora justo encima de la zona de interés, y se fabrica la nanoaguja por ataque iónico justo en esa marca superficial. Finalmente, si es necesario limpiar la superficie de la aguja de material amortizado, se puede hacer observando la nanoaguja durante cierto tiempo con un haz de iones de bajo voltaje. Breve descripción de las figuras This method comprises the deposition of a protective layer (of polymer or metal, etc.) on the surface of the sample, and the removal of the material located on both sides of this protective layer by ionic attack to leave a thin layer of material. Subsequently, this layer of material is taken to a TEM grid with a micromanipulator, where it is thinned to electron transparency by ionic attack. Most of the characteristics of the microstructure of a material are not observable with the FIB secondary electron detector and need to be located in a TEM. Thus, the method comprises the introduction of marks on the surface of the material layer, and the observation of said layer by TEM to find the position of the area of interest with respect to the marks introduced. After this, the surface of the protective layer is marked just above the area of interest, and the nano needle is manufactured by ionic attack just at that surface mark. Finally, if it is necessary to clean the surface of the needle of amortized material, it can be done by observing the nano needle for a certain time with a beam of low-voltage ions. Brief description of the figures
Figura LA.- Representación de la capa protectora sobre la superficie de la muestra.  Figure LA.- Representation of the protective layer on the surface of the sample.
Figura I.B.- Ilustración de las capas de material eliminadas mediante ataque iónico. Figure I.B.- Illustration of the layers of material removed by ionic attack.
Figura l.C- Micromanipulador unido a la capa de material de interés  Figure L.C- Micromanipulator attached to the layer of material of interest
Figura I.D.- Capa de material unida tanto al micromanipulador como a la rejilla de TEM. Figura 2.A.- Capa de material con marcas grabadas y observada en sección transversal. Figure I.D.- Material layer attached to both the micromanipulator and the TEM grid. Figure 2.A.- Material layer with engraved marks and observed in cross section.
Figura 2.B.- Representación del haz de iones durante el ataque para fabricar una nanoaguja.Figure 2.B.- Representation of the ion beam during the attack to make a nano needle.
Figura 3.A.- Capa de material con marca en la superficie de la capa protectora, justo encima de la zona de interés. Figure 3.A.- Material layer with mark on the surface of the protective layer, just above the area of interest.
Figura 3.B.- Capa de material marcada, observada desde arriba.  Figure 3.B.- Layer of marked material, observed from above.
Figura 4.- Imagen de TEM en condiciones 002 en campo oscuro de un QD de InAs/GaAs en una lámina marcada. Figure 4.- Image of TEM in dark field conditions 002 of an InAs / GaAs QD in a marked sheet.
Descripción detallada de la invención Detailed description of the invention
El método para la fabricación de nanoagujas en zonas localizadas que se propone en esta patente requiere de una capa fina de material electrón-transparente unida a una rejilla de TEM. Para obtener esta capa de material, la utilización del FIB es la opción más adecuada ya que es preciso, rápido y fiable, y se puede aplicar a una gran variedad de diferentes materiales. En la literatura, se proponen distintas formas de obtener una capa fina de material mediante FIB; los métodos clásicos son la técnica H-bar (Li, J.; Malis, T.; Dionne, S., Recent advances in FIB-TEM specimen preparation techniques. Mater. Charact. 2006, 57, (1), 64-70) y la técnica lift-out (Mayer, J.; Giannuzzi, L. A.; Kamino, T.; Michael, J., TEM sample preparation and FIB-induced damage. MRS Bull. 2007, 32, (5), 400-407) entre otros, y también se han propuestos algunas variaciones de estos métodos clásicos (Floresca, H. C; Jeon, J.; Wang, J. G. G.; Kim, M. J., The Focused Ion Beam Fold-Out: Sample Preparation Method for Transmission Electron Microscopy. Microsc. microanal. 2009, 15, (6), 558- 563)). Aunque cualquiera de estos métodos son válidos para fabricar la fina capa de material necesaria en el método de la presente invención siempre que sean capaces de controlar el espesor final de dicha capa de material, se recomienda el uso de la técnica in-situ lift-out (Giannuzzi, L. A.; Drown, J. L.; Brown, S. R.; Irwin, R. B.; Stevie, F., Applications of the FIB lift-out technique for TEM specimen preparation. Microsc. Res. Tech. 1998, 41, (4), 285-290; Giannuzzi, L. A.; Drown, J. L.; Brown, S. R.; Irwin, R. B.; Stevie, F. A., Focused ion beam milling and micromanipulation lift-out for site specifíc cross-section TEM specimen preparation. In Specimen Preparation for Transmission Electron Microscopy of Materials Iv, Anderson, R. M.; Walck, S. D., Eds. Materials Research Society: Warrendale, 1997; Vol. 480, pp 19-27; Giannuzzi, L. A.; Stevie, F. A., A review of focused ion beam milling techniques for TEM specimen preparation. Micron 1999, 30, (3), 197-204; Langford, R. M.; Rogers, M., In situ lift-out: Steps to improve yield and a comparison with other FIB TEM sample preparation techniques. Micron 2008, 39, (8), 1325-1330; Overwijk, M. H. F.; Vandenheuvel, F. C.; Bullelieuwma, C. W. T., Novel scheme for the preparation of transmission electron-microscopy specimens with a focused ion-beam. J. Vac. Sci. Technol. B 1993, 1 1, (6), 2021-2024) ya que tiene una alta probabilidad de éxito ya que es un proceso bien controlado; debido a esto, se va a describir este método en detalle. Sin embargo, cabe destacar que esta descripción no pretende limitar esta invención a este método de fabricación de capas electrón-transparentes, ya que cualquier otro método para fabricar dichas capas con las características incluidas en las reivindicaciones es igualmente válido. También cabe destacar que en adelante, en la utilización del FIB el voltage de aceleración del haz de iones estará en el rango 5kV-30 V, siendo un haz de iones Ga, de iones Au, de iones Ar, de iones Li, e iones Be, de iones He o de iones de Au-Si-Be, y la corriente está el rango 1ρΑ-20ηΑ.The method for manufacturing nano-needles in localized areas proposed in this patent requires a thin layer of electron-transparent material attached to a TEM grid. To obtain this layer of material, the use of the FIB is the most appropriate option since it is precise, fast and reliable, and can be applied to a wide variety of different materials. In the literature, different ways of obtaining a thin layer of material by means of FIB are proposed; The classical methods are the H-bar technique (Li, J .; Malis, T .; Dionne, S., Recent advances in FIB-TEM specimen preparation techniques. Mater. Charact. 2006, 57, (1), 64-70 ) and the lift-out technique (Mayer, J .; Giannuzzi, LA; Kamino, T .; Michael, J., TEM sample preparation and FIB-induced damage. MRS Bull. 2007, 32, (5), 400-407 ) among others, and some variations of these classical methods have also been proposed (Floresca, H. C; Jeon, J .; Wang, JGG; Kim, MJ, The Focused Ion Beam Fold-Out: Sample Preparation Method for Transmission Electron Microscopy Microanal microsc. 2009, 15, (6), 558-563)). Although any of these methods are valid for manufacturing the thin layer of material needed in the method of the present invention provided that they are capable of controlling the final thickness of said layer of material, the use of the lift-out in-situ technique is recommended. (Giannuzzi, LA; Drown, JL; Brown, SR; Irwin, RB; Stevie, F., Applications of the FIB lift-out technique for TEM specimen preparation. Microsc. Res. Tech. 1998, 41, (4), 285 -290; Giannuzzi, LA; Drown, JL; Brown, SR; Irwin, RB; Stevie, FA, Focused ion beam milling and micromanipulation lift-out for site specifíc cross-section TEM specimen preparation. In Specimen Preparation for Transmission Electron Microscopy of Materials Iv, Anderson, RM; Walck, SD, Eds. Materials Research Society: Warrendale, 1997; Vol. 480, pp 19-27; Giannuzzi, LA; Stevie, FA, A review of focused ion beam milling techniques for TEM specimen preparation Micron 1999, 30, (3), 197-204; Langford, RM; Rogers, M., In situ lift-out: Steps to improve yie ld and a comparison with other FIB TEM sample preparation techniques. Micron 2008, 39, (8), 1325-1330; Overwijk, MHF; Vandenheuvel, FC; Bullelieuwma, CWT, Novel scheme for the preparation of transmission electron-microscopy specimens with a focused ion-beam. J. Vac. Sci. Technol. B 1993, 1 1, (6), 2021-2024) as it has a high probability of success since it is a well controlled process; Due to this, this method will be described in detail. However, it should be noted that this description is not intended to limit this invention to this method of manufacturing electron-transparent layers, since any other method for manufacturing said layers with the features included in the claims is equally valid. It should also be noted that from now on, in the use of the FIB, the ion beam acceleration voltage it will be in the 5kV-30V range, being a beam of Ga ions, Au ions, Ar ions, Li ions, and Be ions, He ions or Au-Si-Be ions, and the current is the range 1ρΑ-20ηΑ.
La Fig. l.a-d muestra esquemáticamente el proceso de fabricación de una capa electrón- transparente de material mediante el método in-situ lift-out. La Fig. 1.a muestra una capa protectora (1) depositada en la superficie de la muestra (2); normalmente, la capa protectora es una capa de metal depositada con la ayuda del haz de electrones o de iones mediante deposición en fase vapor (CVD), aunque puede estar hecha de otros materiales como C, polímeros, etc. La Fig. 1.b muestra el resultado de eliminar material (3) a ambos lados de la capa protectora (2) mediante ataque con el haz de iones; de esta forma, debe quedar una capa de material de unas 2 μπι de espesor. La corriente del haz de iones para eliminar material debe ser adecuada para la naturaleza del material de la muestra: debe alcanzarse un compromiso de modo que el proceso de ataque no sea excesivamente agresivo, pero que se pueda realizar en un tiempo razonable. La Fig. 1.c muestra el micromanipulador (4) que se une a la capa delgada de material (5); dicha capa debe ser separada de la muestra cortando por la línea de puntos (6) y llevada a la rejilla de TEM (7), como se muestra en la Fig. l.d. La unión de la capa fina de material al micromanipulador o a la rejilla se produce depositando una capa de material (8) entre ellos (puede ser el mismo material que la capa protectora), y la separación de dicha capa del material de partida o del micromanipulador se lleva a cabo por ataque iónico a lo largo de la línea de puntos (6) en las figuras. Fig. 1a-d schematically shows the manufacturing process of an electron-transparent layer of material by means of the in-situ lift-out method. Fig. 1.a shows a protective layer (1) deposited on the surface of the sample (2); Normally, the protective layer is a metal layer deposited with the help of the electron or ion beam by vapor deposition (CVD), although it can be made of other materials such as C, polymers, etc. Fig. 1.b shows the result of removing material (3) on both sides of the protective layer (2) by attack with the ion beam; in this way, a layer of material about 2 μπι thick should remain. The ion beam current to remove material must be adequate for the nature of the sample material: a compromise must be reached so that the attack process is not excessively aggressive, but can be carried out in a reasonable time. Fig. 1.c shows the micromanipulator (4) that joins the thin layer of material (5); said layer must be separated from the sample by cutting along the dotted line (6) and taken to the TEM grid (7), as shown in Fig. l.d. The joining of the thin layer of material to the micromanipulator or to the grid is produced by depositing a layer of material (8) between them (it can be the same material as the protective layer), and the separation of said layer from the starting material or the micromanipulator It is carried out by ionic attack along the dotted line (6) in the figures.
Una vez que la capa de material está unida a la rejilla de TEM, debe ser adelgazada hasta electrón-transparencia. En el método descrito en esta invención, el espesor final de la capa en este paso debe alcanzar un compromiso: debe ser electrón-transparente, ya que la posición de la zona de interés debe ser observable por TEM. Sin embargo, no debe ser demasiado fina, ya que esto la haría demasiado débil para los pasos posteriores de marcar la superficie de la capa y fabricar la nanoaguja. El espesor final deberá ser elegido según la naturaleza del material de la muestra (en general, deberá estar comprendido en el rango 20- 350nm), pero una buena aproximación sería un valor entre 150 y 250nm. La corriente del haz de iones debe ser tan pequeña como sea posible manteniendo un tiempo de ataque razonable, para obtener una buena precisión en el ataque. Debe intentar mantenerse la mayor parte de la capa protectora que se pueda durante el ataque, para lo que es muy últil seguir el proceso de ataque observando con el haz de electrones. Once the layer of material is attached to the TEM grid, it must be thinned to electron transparency. In the method described in this invention, the final thickness of the layer in this step must reach a compromise: it must be electronically transparent, since the position of the area of interest must be observable by TEM. However, it should not be too thin, as this would make it too weak for subsequent steps to mark the surface of the layer and fabricate the nano needle. The final thickness should be chosen according to the nature of the sample material (in general, it should be in the range 20- 350 nm), but a good approximation would be a value between 150 and 250 nm. The ion beam current must be as small as possible while maintaining a reasonable attack time, to obtain good attack accuracy. You should try to keep as much of the protective layer as possible during the attack, for which it is very useful to follow the attack process by observing with the electron beam.
En este punto, la muestra estaría lista para ser observada en TEM y encontrar la posición de la zona de interés, pero no hay que olvidar que la posición de esta zona debe ser reconocible posteriormente en el FIB para poder fabricar la nanoaguja exactamente en esa posición (una gran parte de las características de interés de un sólido no son visibles con el detector de electrones secundarios del FIB). Para conseguir esto, es necesario marcar la capa fina de material con unas marcas que deberán cumplir una serie de requisitos. La idea es que la posición de la zona de interés observada por TEM pueda ser localizada en el FIB a partir de la posición de dichas marcas. Así, como primera condición, las marcas deben ser visibles tanto en TEM como en FIB. Segundo, deben tener la densidad y tamaño apropiadas de modo que la posición de la zona de interés se pueda localizar a partir de la posición de las marcas con un error de localización razonablemente pequeño. Además, la introducción de estas marcas en la capa no debe afectar a la calidad estructural del área de interés que se quiere estudiar, y deben ser eliminadas preferentemente durante el proceso de fabricación de la nanoaguja. La Fig. 2.a muestra una capa electrón-transparente (6) cubierta por una capa protectora (2) donde se han introducido algunas marcas (10) con el haz de iones para localizar la zona de interés A respecto de dichas marcas. Una vez que la capa está marcada, se puede observar en el TEM para encontrar la posición de la zona de interés respecto de las marcas, y luego se llevará al FIB de nuevo para fabricar las nanoagujas. At this point, the sample would be ready to be observed in TEM and find the position of the area of interest, but do not forget that the position of this area must be recognizable later in the FIB to be able to manufacture the nano needle exactly in that position (a large part of the characteristics of interest of a solid are not visible with the secondary electron detector of the FIB). To achieve this, it is necessary to mark the thin layer of material with marks that must meet a series of requirements. The idea is that the position of the area of interest observed by TEM can be located in the FIB from the position of these brands. Thus, as a first condition, brands must be visible in both TEM and FIB. Second, they must have the appropriate density and size so that the position of the area of interest can be located from the position of the marks with a reasonably small location error. In addition, the introduction of these marks in the layer should not affect the structural quality of the area of interest to be studied, and should preferably be eliminated during the nano-needle manufacturing process. Fig. 2.a shows an electron-transparent layer (6) covered by a protective layer (2) where some marks (10) have been introduced with the ion beam to locate the area of interest with respect to said marks. Once the layer is marked, it can be observed in the TEM to find the position of the area of interest with respect to the marks, and then it will be taken back to the FIB to manufacture the nano-needles.
Hay diversos métodos para la fabricación de nanoagujas, tales como electropulido (Melmed, A. J., The art and science and other aspects of making sharp tips. J. Vac. Sci. Technol. B 1991, 9, (2), 601-608), ataque químico (Kim, Y. C; Seidman, D. N., An electrochemical etching procedure for fabricating scanning tunneling microscopy and atom-probe field-ion microscopy tips. Met. Mater.-Int. 2003, 9, (4), 399-404), etc. Sin embargo, los métodos basados en la utilización del FIB son de los únicos con suficiente precisión para ser utilizados en el método de la presente invención. En lo que sigue, se va a explicar el AMM (Larson, D. J.; Foord, D. T.; Petford-Long, A. .; Liew, H.; Blamire, M. G.; Cerezo, A.; Smith, G. D. W. In Field-ion specimen preparation using focused ion-beam milling, Irbid, Jordán, Sep 12-18, 1998; Elsevier Science Bv: Irbid, Jordán, 1998; pp 287-293; Miller, M. K.; Russell, . F.; Thompson, G. B., Strategies for fabricating atom probé specimens with a dual beam FIB. Ultramicroscopy 2005, 102, (4), 287-298), aunque esta descripción no pretende limitar esta invención a dicho método ya que cualquier otro también basado en el uso del FIB y capaz de fabricar una nanoaguja mediante ataque iónico sería también válido. There are various methods for the manufacture of nano-needles, such as electropolishing (Melmed, AJ, The art and science and other aspects of making sharp tips. J. Vac. Sci. Technol. B 1991, 9, (2), 601-608) , chemical attack (Kim, Y. C; Seidman, DN, An electrochemical etching procedure for fabricating scanning tunneling microscopy and atom-probe field-ion microscopy tips. Met. Mater.-Int. 2003, 9, (4), 399- 404), etc. However, the methods based on the use of the FIB are the only ones with sufficient precision to be used in the method of the present invention. In the following, the AMM will be explained (Larson, DJ; Foord, DT; Petford-Long, A..; Liew, H .; Blamire, MG; Cherry, A .; Smith, GDW In Field-ion specimen preparation using focused ion-beam milling, Irbid, Jordan, Sep 12-18, 1998; Elsevier Science Bv: Irbid, Jordan, 1998; pp 287-293; Miller, MK; Russell,. F .; Thompson, GB, Strategies for fabricating atom tested specimens with a dual beam FIB Ultramicroscopy 2005, 102, (4), 287-298), although this description is not intended to limit this invention to said method since any other also based on the use of the FIB and capable of manufacturing a nano needle by ionic attack would also be valid.
La Fig. 2.b muestra un esquema de la aplicación del AMM para fabricar una nanoaguja (11), donde el haz de iones (12) ataca la superficie de la capa protectora (8) según un patrón en forma de anillo con un diámetro interior y exterior determinados. Para aplicar el AMM al método de esta invención, debe tenerse en cuenta la posición relativa de las marcas. Las marcas sólo son visibles con el haz de iones cuando la muestra se observa en sección transversal, sin embargo la nanoaguja se fabrica por ataque iónico desde la superficie superior de la capa protectora, como se muestra en la Fig. 2.b. Así, para fabricar la nanoaguja según las marcas en la sección transversal de la capa, es necesario añadir una marca adicional en la parte superior de la capa protectora, justo encima de una de las marcas anteriores, que podrá tener cualquier forma geométrica de modo que cumpla que la zona en cuestión sea inequívocamente localizable al observarla desde su superficie con el haz de iones, y un tamaño inferior al tamaño final que tendrá la nanoaguja. La Fig. 3.a muestra una visión transversal de la capa donde se muestra la posición de la nueva marca (13) en la superficie superior de la capa protectora (8), y la Fig. 3.b muestra una visión de la parte superior de la capa protectora (8) con la nueva marca (13), como se observaría justo antes de comenzar el ataque iónico para fabricar la nanoaguja. Fig. 2.b shows a scheme of the application of the AMM to manufacture a nano-needle (11), where the ion beam (12) attacks the surface of the protective layer (8) according to a ring-shaped pattern with a diameter interior and exterior determined. To apply the AMM to method of this invention, the relative position of the marks must be taken into account. The marks are only visible with the ion beam when the sample is observed in cross-section, however the nano-needle is manufactured by ionic attack from the upper surface of the protective layer, as shown in Fig. 2.b. Thus, to make the nano-needle according to the marks in the cross section of the layer, it is necessary to add an additional mark on the top of the protective layer, just above one of the previous marks, which may have any geometric shape so that Make sure that the area in question is unequivocally localizable by observing it from its surface with the ion beam, and a size smaller than the final size of the nano-needle. Fig. 3.a shows a cross-sectional view of the layer showing the position of the new mark (13) on the upper surface of the protective layer (8), and Fig. 3.b shows a view of the part upper of the protective layer (8) with the new mark (13), as would be observed just before starting the ionic attack to make the nano-needle.
En esta orientación, se puede fabricar una nanoaguja por ataque iónico, usando un patrón anular de diámetro progresivamente inferior, y eligiendo una serie de corrientes adecuadas en función de la naturaleza del material pero intentando mantenerlas lo más pequeñas posible para conseguir suficiente precisión para fabricar una nanoaguja de reducido diámetro. Una vez que la nanoaguja está fabricada, para algunas aplicaciones como para análisis por TEM es recomendable limpiar la superficie de la aguja observándolo con el haz de iones a 5kV durante algunos minutos. In this orientation, a nano-needle can be manufactured by ionic attack, using an annular pattern of progressively smaller diameter, and choosing a series of suitable currents depending on the nature of the material but trying to keep them as small as possible to achieve sufficient precision to manufacture a nano-needle of reduced diameter. Once the nano needle is manufactured, for some applications such as for TEM analysis it is advisable to clean the surface of the needle by observing it with the 5kV ion beam for a few minutes.
EJEMPLO DE REALIZACIÓN DE LA INVENCIÓN EXAMPLE OF EMBODIMENT OF THE INVENTION
La metodología para la fabricación de nanoagujas en zonas concretas a escala nanométrica localizadas debajo de la superficie de la muestra se puede aplicar a la preparación de muestra para tomografía electrónica de muestras de estructuras epitaxiales de QDs de InAs crecidos sobre substratos de GaAs, en muestras donde la densidad de QDs es muy baja. The methodology for the manufacture of nano-needles in specific areas on a nanometric scale located below the surface of the sample can be applied to the sample preparation for electronic tomography of samples of epitaxial structures of InD QDs grown on GaAs substrates, in samples where The density of QDs is very low.
Para el proceso de fabricación de la nanoaguja, el primer paso del método consiste en proteger la superficie de la muestra para luego eliminar material por ataque iónico hasta formar una capa delgada que será llevada a una rejilla de TEM. Para la mayoría de semiconductores, una deposición de Pt inicial producida con el haz de electrones durante una media hora (15kV, 2nA) es suficiente para reforzar la superficie de la muestra antes de la deposición de Pt mediante el haz de iones (30kV, 0.3nA). Preferiblemente, esta capa de Pt debe tener un espesor de unas 2 μηι, una anchura de entre 1 y 3 μπι, y la longitud puede variar entre 2 y 20 μπι, aproximadamente (normalmente depositamos una capa de unas 10- 15 μιη). Tras esto, se elimina material a ambos lados de la capa de Pt para dejar una capa fina de material de interés; la profundidad de la capa de material que se elimina es normalmente de entre 2 y 10 μπι dependiendo de dónde se encuentre la zona de interés (en nuestro caso, 4 μπι es suficiente), la longitud de esta capa de material a eliminar será ligeramente superior a la longitud de la capa protectora de Pt y la anchura debe ser tal que longitud/anchura=1.5-2. La capa de material de interés final debe ser de unas 2 μπι de espesor. Para eliminar material en este paso, se suelen usar corrientes de 7nA hasta una distancia de 4 μιη de la capa de Pt, y a partir de ahí de InA.  For the nano-needle manufacturing process, the first step of the method is to protect the surface of the sample and then remove material by ionic attack until it forms a thin layer that will be taken to a TEM grid. For most semiconductors, an initial Pt deposition produced with the electron beam for half an hour (15kV, 2nA) is sufficient to reinforce the surface of the sample before the deposition of Pt by the ion beam (30kV, 0.3 nA). Preferably, this layer of Pt should have a thickness of about 2 μηι, a width between 1 and 3 μπι, and the length can vary between approximately 2 and 20 μπι (normally we deposit a layer of about 10-15 μιη). After this, material on both sides of the Pt layer is removed to leave a thin layer of material of interest; The depth of the layer of material that is removed is normally between 2 and 10 μπι depending on where the area of interest is located (in our case, 4 μπι is sufficient), the length of this layer of material to be removed will be slightly longer to the length of the protective layer of Pt and the width should be such that length / width = 1.5-2. The material layer of final interest should be about 2 μπι thick. To remove material in this step, 7nA currents are used up to a distance of 4 μιη from the Pt layer, and from there on InA.
Tras esto, la capa de material se lleva desde la muestra hasta la rejilla de TEM con un micromanipulador. La unión de la capa de GaAs al micromanipulador o a la rejilla de TEM se realiza depositando C con una corriente de O.lnA, mientras que la separación de dicha capa de la muestra o del micromanipulador, por ataque iónico a O.lnA.  After this, the material layer is carried from the sample to the TEM grid with a micromanipulator. The joining of the GaAs layer to the micromanipulator or to the TEM grid is done by depositing C with a current of O.lnA, while the separation of said layer from the sample or the micromanipulator, by ionic attack on O.lnA.
En este punto, la capa de material es adelgazada hasta electrón-transparencia. Como se ha mencionado anteriormente, el espesor final de la capa debe alcanzar un compromiso ya que debe ser transparente a los electrones pero no debe ser demasiado fina ya que esto la haría demasiado débil para los pasos posteriores de marcar la superficie de la capa. Para GaAs, un espesor final de 250nm es aceptable. La corriente para este proceso de adelgazamiento debe reducirse secuencialmente para mejorar la precisión del ataque químico a la vez que se optimiza la duración del proceso. Para GaAs, se puede usar O.lnA hasta que la capa de material mida unos 400nm de espesor aproximadamente, y 0.05nm hasta que mida unos 250nm. At this point, the material layer is thinned to electron transparency. As mentioned above, the final thickness of the layer must reach a compromise since it must be transparent to the electrons but it should not be too thin as this would make it too weak for subsequent steps to mark the surface of the layer. For GaAs, a final thickness of 250nm is acceptable. The current for this thinning process must be reduced sequentially to improve the accuracy of the chemical attack while optimizing the duration of the process. For GaAs, O.lnA can be used until the layer of material measures approximately 400nm thick, and 0.05nm until it measures about 250nm.
El siguiente paso en el método de esta patente consiste en marcar la capa de material y llevarla al TEM, para observar la posición de los QDs y ser capaz de localizarlos en el FIB tomando como referencia las marcas introducidas. Dichas marcas deben cumplir los requerimientos mencionados anteriormente. Para ello y sabiendo que los QDs tienen un diámetro de unos 25-30nm, se han diseñado las marcas como una línea de círculos grabados en la superficie de la capa con el haz de iones, con diámetro de 50nm y profundidad de <50nm, cuyos centros están separados unos 150nm. Estas marcas se graban en la capa de GaAs situada sobre los puntos de InAs, ya que si se grabaran en la capa de Pt, lo cual sería más seguro para la muestra, no se observan bien en el TEM. Se recomienda que la capa de material tenga una longitud máxima de 3 μπι, ya que si no un número excesivo de marcas en la capa haría difícil localizar los QDs en el FIB. Si la capa de material original es más larga de 3 μιη, puede ser cortada en capas más pequeñas cuando se lleva a la rejilla de TEM. Una vez que la capa está marcada, se puede observar en el TEM. La Fig. 4 muestra una imagen de TEM de la muestra marcada en condiciones 002 en campo oscuro, donde se incluye uno de los puntos de InAs.  The next step in the method of this patent is to mark the layer of material and take it to the TEM, to observe the position of the QDs and to be able to locate them in the FIB taking as reference the introduced marks. These marks must meet the requirements mentioned above. To do this and knowing that the QDs have a diameter of about 25-30nm, the marks have been designed as a line of circles engraved on the surface of the layer with the ion beam, with a diameter of 50nm and depth of <50nm, whose centers are separated about 150nm. These marks are recorded in the GaAs layer located above the InAs points, since if they were recorded in the Pt layer, which would be safer for the sample, they are not well observed in the TEM. It is recommended that the material layer has a maximum length of 3 μπι, otherwise an excessive number of marks in the layer would make it difficult to locate the QDs in the FIB. If the layer of original material is longer than 3 μιη, it can be cut into smaller layers when carried to the TEM grid. Once the layer is marked, it can be observed in TEM. Fig. 4 shows a TEM image of the sample marked in conditions 002 in a dark field, where one of the InAs points is included.
Para fabricar la nanoaguja en la posición donde está el QD (una vez que ha sido observado en TEM), necesitamos seleccionar la marca más próxima a dicho QD, y grabar una nueva marca en la superficie de la capa de Pt. Para esta aplicación experimental particular, la nueva marca es un cilindro de diámetro 50-100nm y profundidad 250nm justo en la superficie del Pt. La nueva marca servirá para localizar la posición donde se fabricará la nanoaguja. Para obtener una nanoaguja de pequeño diámetro, (<100nm) para optimizar el análisis por tomografía electrónica, se debe atacar con el haz de iones a un voltaje reducido de 20kV. Esto normalmente se lleva a cabo en dos pasos, el primero hasta un diámetro de 200nm, y el segundo hasta el diámetro final de la nanoaguja. Finalmente, la calidad de la superficie de la nanoaguja se puede mejorar observando la nanoaguja a 5kV durante algunos minutos (<30min, dependiendo de la magnificación), para reducir el espesor de la capa de amorfo superficial.  To make the nano needle in the position where the QD is (once it has been observed in TEM), we need to select the closest mark to that QD, and engrave a new mark on the surface of the Pt layer. For this experimental application In particular, the new brand is a cylinder of 50-100nm diameter and 250nm depth just on the surface of the Pt. The new brand will be used to locate the position where the nano-needle will be manufactured. To obtain a small diameter nano needle, (<100nm) to optimize the analysis by electronic tomography, the ion beam must be attacked at a reduced voltage of 20kV. This is usually carried out in two steps, the first to a diameter of 200nm, and the second to the final diameter of the nano needle. Finally, the surface quality of the nano-needle can be improved by observing the nano-needle at 5kV for a few minutes (<30min, depending on the magnification), to reduce the thickness of the surface amorphous layer.

Claims

REIVINDICACIONES
1.- Método para la fabricación de nanoagujas en zonas de interés localizadas en el interior de muestras sólidas a escala nanométrica, que partiendo del depósito de una capa de material protector en la superficie de la muestra, la eliminación del material de la muestra a ambos lados de la capa protectora de manera que se deje una capa fina de muestra, la unión de dicha capa fina de muestra a un micromanipulador, cortar la unión entre la capa fina de material y el resto de la muestra, y llevar dicha capa fina de material con el micromanipulador a una rejilla de microscopía electrónica de transmisión, comprende los siguientes pasos: 1.- Method for the manufacture of nano-needles in areas of interest located inside solid samples on a nanometric scale, which, starting from the deposit of a layer of protective material on the surface of the sample, the removal of the sample material from both sides of the protective layer so that a thin sample layer is left, the attachment of said thin sample layer to a micromanipulator, cut the joint between the thin layer of material and the rest of the sample, and carry said thin layer of material with the micromanipulator to a grid of transmission electron microscopy, comprises the following steps:
• Fabricación de una capa de material electrón-transparente unida a una rejilla de TEM.  • Manufacture of a layer of electronically transparent material attached to a TEM grid.
• Grabar una serie de marcas en la superficie de la capa de material en sección transversal con un haz de iones focalizados.  • Engrave a series of marks on the surface of the material layer in cross section with a focused ion beam.
· Llevar la capa de material marcado al TEM para localizar la zona de interés.  · Bring the layer of material marked to the TEM to locate the area of interest.
• Grabar una marca en la superficie superior de la capa protectora justo sobre la zona de interés con un haz de iones focalizados.  • Engrave a mark on the upper surface of the protective layer just above the area of interest with a beam of focused ions.
• Fabricar una nanoaguja en la posición señalada por esta nueva marca con el haz de iones focalizados.  • Manufacture a nano needle in the position indicated by this new brand with the focused ion beam.
2.- Método para la fabricación de nanoagujas en zonas de interés localizadas en el interior de muestras sólidas a escala nanométrica, según la reivindicación 1, donde la capa de material formada por ataque iónico tiene un espesor de entre 20 y 350nm. 2. Method for the manufacture of nano-needles in areas of interest located inside solid samples on a nanometric scale, according to claim 1, wherein the layer of material formed by ionic attack has a thickness of between 20 and 350 nm.
3.- Método para la fabricación de nanoagujas en zonas de interés localizadas en el interior de muestras sólidas a escala nanométrica, según la reivindicación 1, donde el voltaje de aceleración del haz de iones está en el rango 5kV-30kV, y la corriente está en el rango lpA- 20nA. 3. Method for the manufacture of nano-needles in areas of interest located inside solid samples on a nanometric scale, according to claim 1, wherein the ion beam acceleration voltage is in the range 5kV-30kV, and the current is in the range lpA-20nA.
4.- Método para la fabricación de nanoagujas en zonas de interés localizadas en el interior de muestras sólidas a escala nanométrica, según la reinvindicación 1, donde el haz de iones focalizados es de iones Ga, de iones Au, de iones Ar, de iones Li, e iones Be, de iones He o de iones de Au-Si-Be. 4.- Method for the manufacture of nano-needles in areas of interest located inside solid samples on a nanometric scale, according to reinvindication 1, where the focused ion beam is of Ga ions, Au ions, Ar ions, ions Li, Be ions, He ions or Au-Si-Be ions.
5. - Método para la fabricación de nanoagujas en zonas de interés localizadas en el interior de muestras sólidas a escala nanométrica, según la reivindicación 1, donde las marcas deben ser visibles tanto en TEM como en FIB. 5. - Method for the manufacture of nano-needles in areas of interest located inside solid samples on a nanometric scale, according to claim 1, where the marks must be visible in both TEM and FIB.
6. - Método para la fabricación de nanoagujas en zonas de interés localizadas en el interior de muestras sólidas a escala nanométrica, según la reivindicación 1, donde las marcas deben tener la densidad y tamaño apropiadas de modo que la posición de la zona de interés se pueda localizar a partir de la posición de las marcas con un error de localización suficientemente pequeño como para alcanzar el objetivo del método. 6. - Method for the manufacture of nano-needles in areas of interest located inside solid samples on a nanometric scale, according to claim 1, wherein the marks must have the appropriate density and size so that the position of the area of interest is can locate from the position of the marks with a location error small enough to achieve the objective of the method.
7. - Método para la fabricación de nanoagujas en zonas de interés localizadas en el interior de muestras sólidas a escala nanométrica, según la reivindicación 1, donde la marca en la superficie superior de la capa protectora grabada con el haz de iones tenga cualquier forma geométrica de modo que cumpla que la zona en cuestión sea inequívocamente localizable al observarla desde su superficie con el haz de iones. 7. - Method for the manufacture of nano-needles in areas of interest located inside solid samples on a nanometric scale, according to claim 1, wherein the mark on the upper surface of the protective layer etched with the ion beam has any geometric shape so that it complies that the area in question is unequivocally traceable when viewed from its surface with the ion beam.
8. - Método para la fabricación de nanoagujas en zonas de interés localizadas en el interior de muestras sólidas a escala nanométrica, según la reivindicación 1 , donde el tamaño de la marca en la superficie superior de la capa protectora sea inferior al tamaño final que tendrá la nanoaguja. 8. - Method for the manufacture of nano-needles in areas of interest located inside solid samples on a nanometric scale, according to claim 1, wherein the size of the mark on the upper surface of the protective layer is smaller than the final size it will have The nano needle.
9. - Método para la fabricación de nanoagujas en zonas de interés localizadas en el interior de muestras sólidas a escala nanométrica, según la reivindicación 1, donde la nanoaguja se fabrica recomendablemente con un patrón en forma de anillo, o con cualquier otro de los procedimientos mencionados en la literatura que tengan la precisión requerida. 9. - Method for the manufacture of nano-needles in areas of interest located inside solid samples on a nanometric scale, according to claim 1, wherein the nano-needle is preferably manufactured with a ring-shaped pattern, or with any other procedure mentioned in the literature that have the required precision.
10. - Método para la fabricación de nanoagujas en zonas de interés localizadas en el interior de muestras sólidas a escala nanométrica, según la reivindicación 1 donde la nanoaguja se fabrica con una serie de corrientes lo suficientemente pequeñas como para que dicha nanoaguja tenga un diámetro reducido, dichas corrientes dependerán del material con el que se esté trabajando. 10. - Method for the manufacture of nano-needles in areas of interest located inside solid samples on a nanometric scale, according to claim 1 wherein the nano-needle is manufactured with a series of streams small enough so that said nano-needle has a reduced diameter , these currents will depend on the material with which you are working.
PCT/ES2011/000180 2010-07-12 2011-05-30 Method for manufacturing nanoneedles in areas of interest located inside solid samples on the nanometre scale WO2012007602A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
ES201000911A ES2372846B2 (en) 2010-07-12 2010-07-12 METHOD FOR MANUFACTURING NANOAGUJAS IN AREAS OF INTEREST LOCATED INSIDE SOLID SAMPLES AT NANOMETRIC SCALE.
ESP201000911 2010-07-12

Publications (1)

Publication Number Publication Date
WO2012007602A1 true WO2012007602A1 (en) 2012-01-19

Family

ID=45446406

Family Applications (1)

Application Number Title Priority Date Filing Date
PCT/ES2011/000180 WO2012007602A1 (en) 2010-07-12 2011-05-30 Method for manufacturing nanoneedles in areas of interest located inside solid samples on the nanometre scale

Country Status (2)

Country Link
ES (1) ES2372846B2 (en)
WO (1) WO2012007602A1 (en)

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104713767A (en) * 2013-12-17 2015-06-17 中芯国际集成电路制造(上海)有限公司 TEM sample preparation method

Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP1209737A2 (en) * 2000-11-06 2002-05-29 Hitachi, Ltd. Method and apparatus for specimen fabrication
US20030183776A1 (en) * 1997-07-22 2003-10-02 Satoshi Tomimatsu Method and apparatus for specimen fabrication
US20040245464A1 (en) * 2003-06-02 2004-12-09 Kouji Iwasaki Thin specimen producing method and apparatus
WO2008051880A2 (en) * 2006-10-20 2008-05-02 Fei Company Method and apparatus for sample extraction and handling

Patent Citations (4)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US20030183776A1 (en) * 1997-07-22 2003-10-02 Satoshi Tomimatsu Method and apparatus for specimen fabrication
EP1209737A2 (en) * 2000-11-06 2002-05-29 Hitachi, Ltd. Method and apparatus for specimen fabrication
US20040245464A1 (en) * 2003-06-02 2004-12-09 Kouji Iwasaki Thin specimen producing method and apparatus
WO2008051880A2 (en) * 2006-10-20 2008-05-02 Fei Company Method and apparatus for sample extraction and handling

Cited By (1)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
CN104713767A (en) * 2013-12-17 2015-06-17 中芯国际集成电路制造(上海)有限公司 TEM sample preparation method

Also Published As

Publication number Publication date
ES2372846B2 (en) 2012-07-09
ES2372846A1 (en) 2012-01-27

Similar Documents

Publication Publication Date Title
Wu et al. Control of shape and material composition of solid-state nanopores
US8920723B2 (en) Sample support structure and methods
JP6418747B2 (en) Sample preparation stage
Giddings et al. Composition profiling of InAs quantum dots and wetting layers by atom probe tomography and cross-sectional scanning tunneling microscopy
Shaffir et al. The mechanism of initial de-wetting and detachment of thin Au films on YSZ
Gierak Focused Ion Beam nano-patterning from traditional applications to single ion implantation perspectives
CN102062710A (en) Preparation method of observation sample for transmission electron microscope
CN107860620B (en) Transmission electron microscope sample and preparation method thereof
Hernández-Saz et al. A methodology for the fabrication by FIB of needle-shape specimens around sub-surface features at the nanometre scale
WO2012007602A1 (en) Method for manufacturing nanoneedles in areas of interest located inside solid samples on the nanometre scale
Zhang et al. Fabrication of ultrafine nanostructures with single-nanometre precision in a high-resolution transmission electron microscope
US20090160307A1 (en) Diamond electron source and method for manufacturing the same
US10782313B2 (en) Method of fabricating nano-scale structures on the edge and nano-scale structures fabricated on the edge using the method
JP2010230518A (en) Thin sample preparing method
Xu et al. Recent developments in focused ion beam and its application in nanotechnology
EP3922752A1 (en) A method for preparing a sample for transmission electron microscopy
Nazriq et al. CO-tip manipulation using repulsive interactions
CN105223383B (en) A kind of preparation method of plane TEM sample
KR101161259B1 (en) Manufacturing method of sample for TEM analysis
McKenzie et al. Focused ion beam sample preparation for atom probe tomography
Zhu et al. The growth of bismuth on Bi2Se3 and the stability of the first bilayer
Li et al. Size-dependent dissociation of small cobalt clusters on ultrathin NaCl films
Mosberg et al. Bending Needles and Breaking Wires: Useful Failures in Nanowire Probing
US20220349789A1 (en) Method to prepare a sample for atom probe tomography (apt), preparation device to perform such method and method to investigate a region of interest of a sample including such performing method
JP4316400B2 (en) Surface layer evaluation method

Legal Events

Date Code Title Description
121 Ep: the epo has been informed by wipo that ep was designated in this application

Ref document number: 11806321

Country of ref document: EP

Kind code of ref document: A1

NENP Non-entry into the national phase

Ref country code: DE

122 Ep: pct application non-entry in european phase

Ref document number: 11806321

Country of ref document: EP

Kind code of ref document: A1