Classifications

• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
  • G03F7/0042—Photosensitive materials with inorganic or organometallic light-sensitive compounds not otherwise provided for, e.g. inorganic resists
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
  • G03F7/0042—Photosensitive materials with inorganic or organometallic light-sensitive compounds not otherwise provided for, e.g. inorganic resists
  • G03F7/0043—Chalcogenides; Silicon, germanium, arsenic or derivatives thereof; Metals, oxides or alloys thereof
• • G—PHYSICS
  • G03—PHOTOGRAPHY; CINEMATOGRAPHY; ANALOGOUS TECHNIQUES USING WAVES OTHER THAN OPTICAL WAVES; ELECTROGRAPHY; HOLOGRAPHY
  • G03F—PHOTOMECHANICAL PRODUCTION OF TEXTURED OR PATTERNED SURFACES, e.g. FOR PRINTING, FOR PROCESSING OF SEMICONDUCTOR DEVICES; MATERIALS THEREFOR; ORIGINALS THEREFOR; APPARATUS SPECIALLY ADAPTED THEREFOR
  • G03F7/00—Photomechanical, e.g. photolithographic, production of textured or patterned surfaces, e.g. printing surfaces; Materials therefor, e.g. comprising photoresists; Apparatus specially adapted therefor
  • G03F7/004—Photosensitive materials
  • G03F7/0047—Photosensitive materials characterised by additives for obtaining a metallic or ceramic pattern, e.g. by firing
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/02—Manufacture or treatment of semiconductor devices or of parts thereof
  • H01L21/04—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer
  • H01L21/18—Manufacture or treatment of semiconductor devices or of parts thereof the devices having potential barriers, e.g. a PN junction, depletion layer or carrier concentration layer the devices having semiconductor bodies comprising elements of Group IV of the Periodic Table or AIIIBV compounds with or without impurities, e.g. doping materials
  • H01L21/28—Manufacture of electrodes on semiconductor bodies using processes or apparatus not provided for in groups H01L21/20 - H01L21/268
  • H01L21/283—Deposition of conductive or insulating materials for electrodes conducting electric current
  • H01L21/288—Deposition of conductive or insulating materials for electrodes conducting electric current from a liquid, e.g. electrolytic deposition
• • H—ELECTRICITY
  • H01—ELECTRIC ELEMENTS
  • H01L—SEMICONDUCTOR DEVICES NOT COVERED BY CLASS H10
  • H01L21/00—Processes or apparatus adapted for the manufacture or treatment of semiconductor or solid state devices or of parts thereof
  • H01L21/70—Manufacture or treatment of devices consisting of a plurality of solid state components formed in or on a common substrate or of parts thereof; Manufacture of integrated circuit devices or of parts thereof
  • H01L21/71—Manufacture of specific parts of devices defined in group H01L21/70
  • H01L21/768—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics
  • H01L21/76838—Applying interconnections to be used for carrying current between separate components within a device comprising conductors and dielectrics characterised by the formation and the after-treatment of the conductors
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K3/00—Apparatus or processes for manufacturing printed circuits
  • H05K3/10—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern
  • H05K3/105—Apparatus or processes for manufacturing printed circuits in which conductive material is applied to the insulating support in such a manner as to form the desired conductive pattern by conversion of non-conductive material on or in the support into conductive material, e.g. by using an energy beam
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K1/00—Printed circuits
  • H05K1/02—Details
  • H05K1/03—Use of materials for the substrate
  • H05K1/0306—Inorganic insulating substrates, e.g. ceramic, glass
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K2203/00—Indexing scheme relating to apparatus or processes for manufacturing printed circuits covered by H05K3/00
  • H05K2203/10—Using electric, magnetic and electromagnetic fields; Using laser light
  • H05K2203/107—Using laser light
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K2203/00—Indexing scheme relating to apparatus or processes for manufacturing printed circuits covered by H05K3/00
  • H05K2203/12—Using specific substances
  • H05K2203/121—Metallo-organic compounds
• • H—ELECTRICITY
  • H05—ELECTRIC TECHNIQUES NOT OTHERWISE PROVIDED FOR
  • H05K—PRINTED CIRCUITS; CASINGS OR CONSTRUCTIONAL DETAILS OF ELECTRIC APPARATUS; MANUFACTURE OF ASSEMBLAGES OF ELECTRICAL COMPONENTS
  • H05K3/00—Apparatus or processes for manufacturing printed circuits
  • H05K3/02—Apparatus or processes for manufacturing printed circuits in which the conductive material is applied to the surface of the insulating support and is thereafter removed from such areas of the surface which are not intended for current conducting or shielding

Definitions

• the present invention relates to the field of physical chemistry and more particularly that of surface treatment methods. It relates to an improved lithography process as well as the products obtained by the implementation of said process and is particularly useful in the manufacture of micro- or nanometric products or objects.
• the present invention allows in particular a simplified manufacture of multilayer electronic structures, in particular of multilayer meso and nanostructures for optical and electronic applications and in particular of printed circuits or field effect transistors commonly designated by the Anglo-Saxon name. "MOS-FET transistor".
• MOS-FET transistor Currently, the manufacture of industrial components of the aforementioned type requires tracing of the active and passive components using masks produced in the form of a layer of polymer (typically made of polymethyl methacrylate: PMMA).
• These masks are produced on the substrate by local depolymerization of said uniform layer of PMMA by a light source through a metal mask, namely blades pierced at the places to be subjected to irradiation.
• the critical irradiation step is generally carried out by an ultraviolet light flux which depolymerizes, at the places not covered by said masks, an underlying polymer.
• the degraded polymer is then removed by washing the substrate to reveal the desired pattern or structure. This process is then repeated until the desired multilayer pattern or final product is obtained.
• the wavelength of the irradiation sources currently used generally does not allow the production of objects, for example electronic components, of size less than 200 nm.
• the method according to the invention makes it possible to manufacture in a simplified manner nanometric objects of magnetic oxide or not, metallic nanometric objects or made of certain semiconductors. It dispenses tedious and delicate masking steps, of manufacturing polymer imprints and also allows the formation of nanometric conductive tracks preferably made of copper and / or gold and the formation of certain semiconductors.
• the subject of the present invention is a lithography process, characterized in that it essentially comprises the steps consisting in: a) depositing, on a substrate, a film of a metalloorganic solution containing at least one metallic ion in as a precursor (s) intended to mark said substrate, b) locally exposing, according to the desired pattern, the film obtained in step a) to at least one focused energy beam having an energy density sufficient to at least dry locally said film of precursor (s), c) dissolve the areas not exposed in step b) using a solvent for the metallo-organic solution deposited in step a), the at least dried areas remaining on said substrate, d) if necessary, subjecting the product obtained in the previous step to a heat treatment with a view to obtaining, at the exposed areas, the magnetic oxide, the metal, the semiconductor or the neutral oxide or their melan ges from said metallo-organic solution, and e) if necessary, repeat steps a) - d), possibly changing the metallo-organic solution,
• the method according to the invention avoids the heavy steps usually resorting to the physical methods of metallic deposits by sublimation under ultra high vacuum (as known under designations of "MBE” and “sputtering") with the successive and tedious masking steps for the formation of nanometric objects such as in particular the transistors of the "MOS FET” (metal oxide semiconductor field effect transitor) type mentioned above.
• MBE ultra high vacuum
• MOS FET metal oxide semiconductor field effect transitor
• the manufacture of nanometric objects made using a scanning electron microscope connected to a computer making it possible to control the position of the energy beam (for example an electron beam) with a high precision.
• a thin layer of precursor solution is deposited on the surface of a sample of substrate to be treated and the electron beam dries and / or transforms said precursor into substance to be deposited.
• a combination of solvents subsequently dissolves unexposed regions.
• the wavelength of electrons is much smaller than that of ultraviolet. This provides a significantly higher resolution.
• the use of a scanning electron microscope controlled by a computer means that it is not necessary to have complex photo-lithographic masks made to measure, therefore expensive, as is the case, for example, for ultraviolet lithography.
• this is done by direct writing on the samples or substrates of interest and the technique thus offers a lot of flexibility for the rapid modification of the written patterns.
• FIG. 1 represents the photo of a first example of an object made of Fe 2 0 3 on silicon 100 thanks to the implementation of the method according to the invention
• FIG. 2 represents an enlargement of a portion of the photo of FIG. 1
• FIG. 3 represents the photo of a second example of an object produced in CoFe 2 0 on silicon 100 thanks to the implementation of the method according to the invention
• FIG. 4 represents an enlargement of a portion of the photo of FIG. 3
• FIG. 5 represents the photo of a third example of an object made of metal (gold) thanks to the implementation of the method according to the invention.
• the lithography method is characterized in that it essentially comprises the steps consisting in: a) depositing, on a substrate, a film of a metalloorganic solution containing at least one metal ion as a precursor ( s) intended to mark said substrate, b) locally exposing, according to the desired pattern, the film obtained in step a) to at least one focused energy beam having an energy density sufficient to at least locally dry said film of precursor (s), c) dissolve the areas not exposed in step b) using a solvent for the metallo-organic solution deposited in step a), the at least dried areas remaining on said substrate, d) if necessary, subject the product obtained in the preceding step to a heat treatment with a view to obtaining, in the exposed areas, the magnetic oxide, the metal, the semiconductor or the neutral oxide or their mixtures i ssus of said metallo-organic solution, and e) if necessary, repeat steps a) - d), possibly changing the metallo-organic solution
• a metallo-organic solution is deposited, preferably by “spin-coating” (rotary deposition) on a flat substrate, in particular of silicon or of vitreous material.
• spin-coating rotary deposition
• the metallo-organic coating or layer is then exposed to said beam.
• the said coating is degraded and becomes insoluble in common solvents (alcohol, acetone, water, etc.).
• solvents alcohol, acetone, water, etc.
• the non-irradiated parts are then dissolved, revealing the engraved submicron or nanometric objects.
• Said substrate can then undergo a new overall coating to deposit another layer of another organic metalloor or simply be heat treated to form in the undissolved zones a magnetic oxide (for example Fe 2 O 3 , CoFe 2 O 4 .. .), a metal (Cu, Co %) a semiconductor (CdS, CdSe, ZnS, ZnSe ...), a neutral oxide (Ti0 2 , A1 2 0 3 , ZnO ...) depending on the device that you want to train or complete.
• the apparatus used for the manufacture of micro or nanostructures as well as for their observation is a scanning electron microscope as known, for example, under the reference JEOL-JMS 6300 from the manufacturer JEOL.
• a scanning electron microscope SEM
• SEM scanning electron microscope
• the maximum energy of the electrons produced by this SEM is around 30 keV.
• SEM is connected to a conventional personal computer which controls the position of the electron beam according to a process known per se and which does not need to be explained in more detail here.
• the computer also controls a beam interceptor located above the sample.
• the substrate is silicon or cleaved mica.
• the surface of the substrate is that of a single crystal.
• the substrate is a ceramic, in particular a glass.
• the substrate is a metal or a metal alloy.
• the metallo-organic solution contains at least one organic salt of at least one metal chosen from the group formed by: Cd, Ti, Al, Si, Fe, Co, Ni, Mn, Cr, Zn, Cu, Ca, Ba, Sr, Y, Zr, Sn, Ag, La, Hf, Ta, Pb, Bi, In, Ce, Pr, Nd, Sm, Eu, Gd, Yb, Er, Tb and U.
• the metallo-organic salts are chosen from the group formed by: carboxylates, propionates, butyrates, pentanoates, metal methylbutyrates or a mixture of these.
• the metallo-organic solution also comprises at least one mineral salt of at least one noble metal chosen from the group formed by Au, Ag and Pt, preferably AuCl 3 , AgNO 3 , or PtCl 5 or a mixture thereof.
• the energy beam is an electron beam or an ion beam.
• the energy density of the energy beam is between 100 and 100,000 Asm "2.
• the energy density of the energy beam is sufficient to modify, in the exposed areas, the chemical nature of the metal or metals contained in the solution
• the metalloorganic solution containing at least Cd or Zn also contains a compound capable of releasing sulphide ions at the time of the exposure in step b) and / or during the heat treatment of step d).
• the desired pattern (insulating, magnetic deposit, line for future conductive tracks or current leads 7) is prepared on a specific CAD software also known per se and is then interpreted in terms of electron beam displacement orders point by point The electron or ion beam dries and / or transforms the precursor used as indicated above.
• said precursors will have been spread over the samples using a device making it possible to deposit them uniformly on the substrate, for example using a device commonly known as a "spinner" in technical jargon. in question.
• a drop of metallo-organic solution is thus deposited on the sample (or substrate) which is subsequently rotated at a speed of the order of 5000 revolutions per minute for 60 seconds.
• a solvent or a combination of solvents is used as developer, that is to say as a substance making it possible to eliminate only the molecules which have not been exposed.
• the process implemented therefore reveals, after washing, for a longitudinal irradiation a line in relief or for irradiation on a circular surface a disc in relief.
• a metal layer must be evaporated over the entire surface of the developed sample.
• the metal can be evaporated in two ways: thermally or by an electron gun. In the first case, a small amount of metal is put in a tungsten crucible and is heated above the boiling point, under vacuum, in the presence of the sample or substrate. In the second case, the metal is heated by an electron gun.
• the most commonly used metals for nano-fabrication are NiCr (eutectic alloy of nickel and chromium), as well as AuPd (eutectic alloy of gold and palladium) and are thermally evaporated.
• the electron gun evaporator is generally used for evaporations of multiple layers of different metals, as necessary for ohmic contacts or Schottky contacts.
• This process is done by soaking the sample in a mixture of acetone and MEK (methyl ethyl ketone), strong solvents, which dissolve all the resin , regardless of its molecular weight. After a while, the solvents are stirred so that the metal on the resin is removed.
• Two mixtures are widely used here as developers, namely, on the one hand, a mixture of isopropyl alcohol and water (IPA: H 2 0) and, on the other hand, a mixture of isopropyl alcohol and methyl isobutyl ketone (IPA: MIBK).
• IPA isopropyl alcohol and water
• MIBK methyl isobutyl ketone
• the most widely used solvents for resins are methyl isobutyl ketone (MIBK), orthoxylene and chlorobenzene. Chlorobenzene is the strongest of these solvents and is used for the highest PMMA concentrations (for example of the order of 15%). For lower concentrations, typically between 2.5% to 6% by weight of PPMA, orthoxylene is perfectly suitable. Thanks to the process according to the invention, no organic polymer is therefore required, nor, consequently, any costly, harmful and polluting solvent for the traditional “lift-off” step mentioned above, unnecessary in the process according to the present invention. .
• MIBK methyl isobutyl ketone
• chlorobenzene chlorobenzene
• the method according to the invention is similar to a direct lithography technique in that, in addition to requiring only a single etching step (saving time during etching and during quality control thereof) , it does not use any masking. Just as much as the substantial drop in the final cost price of a component manufactured by the process according to the invention, the very great diversity of materials that can be produced (magnetic oxides, semiconductors, conductive or insulating tracks, etc.) is another. significant advantage. Thus, by way of example, metallic objects can now be obtained without resorting to the heavy step of vaporizing metal.
• the method according to the invention is all the more flexible as the chemical nature of the substrate practically does not condition the success of the lithography.
• the method according to the present invention can be used in the field of microelectronics, in the catalysis of oriented nanotubes for plasma screens, for bio-chips, for very high density magnetic recording, for the manufacture of logic gates, GMR memories, UV-Visible detectors, for the security marking of components, for the manufacture of micromachines ...
• the process according to the invention will now be explained in more detail with the aid of the following examples given without implied limitation.
• An iron propionate solution is prepared by dissolving iron propionate in a suitable solvent such as ethanol, propanol, butanol or acetone. To obtain an oxide layer typically of the order of 0.2 ⁇ m, a solution of 1 mole per liter of iron propionate will be prepared.
• the substrate typically monocrystalline silicon 100 lambda polished out of 10 and previously cleaned by means well known to those skilled in the art, is deposited on the spinner, a device conventionally used in microelectronics and making it possible to deposit layers by centrifugation.
• a few drops of the aforementioned iron propionate solution are deposited on the substrate so that the latter is typically covered with solution without overflowing, then the substrate is rotated at a speed of between approximately 1000 and 5000 rpm for, example, 30 seconds.
• the deposited liquid spreads out to form a thin film of a few tenths of a micrometer (0.3 to 0.6 ⁇ m).
• the substrate thus prepared is carefully removed from the device and placed in a box protected from dust (especially if this operation does not take place in a clean room) and transferred to an electrolithography device.
• the diagrams of the nano-objects that one wishes to manufacture will have been designed and programmed in the usual way on CAD software (of the type known under the name “Autocad” or compatible) and transcribed into corresponding displacements of the beam of electrons in the device.
• the prepared substrate therefore undergoes point irradiations as provided with an ion beam typically of the order of 1000 Asm " .
• the irradiation allowing the formation of a network of one hundred parallel wires of some 200 nm thick and d '' a wide micrometer separated from a micrometer lasts about a few minutes (from 0, 1 to 3 minutes depending on the dose and the thickness of the sample).
• the manufacturing procedure is similar to the previous procedure, only the composition of the solution being modified.
• the iron and cobalt propionates will be dissolved in the proportions of two iron atoms for one cobalt atom.
• the final heat treatment will be carried out at a temperature of 700 ° C-800 ° C and for a sufficient time to obtain the desired chemical compound.
• This manufacturing type is applicable to obtaining both binary oxides of spinel, perovskite, garnet or hexaferrite type which may be of interest in microelectronics or in quantum electronics.
• Figures 3 and 4 represent photos of an example of objects produced in CoFe 2 0 4 on Si 100 thanks to the implementation of the method according to the invention.
• Example 3 Manufacture of nanometric metal studs or tracks in cobalt, iron or copper
• FIG. 5 represents a photo of an example of a structure produced in metallic gold thanks to the implementation of the method according to the invention.
• Example 2 The manufacturing procedure is similar to that of Example 1, only the composition of the solution being modified. We will dissolve cadmium carboxylate and add to this solution an excess of a compound capable of releasing sulphide ions during its decomposition, typically thiourea. During the irradiation stage, the thiourea decomposes, releasing the sulphide ions which immediately combine with cadmium to form the desired semiconductor CdS.
• thiourea a compound capable of releasing sulphide ions during its decomposition
• Example 5 Preparation of nanometric objects of insulator such as TiO ?, Al 2 O ⁇ or SiO?
• the manufacturing procedure is similar to that of case 1, only the composition of the solution being modified.
• the titanium, aluminum or silicon carboxylate will be dissolved.
• the oxidative heat treatment in air will be carried out at approximately 600 ° C.
• the method according to the invention makes it possible to fabricate structures of the order of ten nanometers. As an indication, it becomes possible, for example, to reproducibly make a metal line about 45 nm wide, a point with a width of less than 50 nm, as well as a spacing between two metallic structures of about 15 nm.
• the method according to the invention is therefore an advanced technique for the manufacture of electronic components in the sense that it makes it possible to significantly reduce the value of 190 nm usually encountered for the door width of a transistor to a door width included between 2 and 100 nm.
• the present invention also relates to a multilayer manufactured device, characterized in that it comprises at least one structure or pattern obtained by implementing the method according to the invention.
• the present invention also relates to the use of the method according to the invention in the manufacture of electronic components, in particular transistors and more preferably field effect transistors as well as in the manufacture of printed circuits.
• the method according to the invention in particular by providing the usual steps for doping silicon (implantation by phosphorus ions for the creation of doped zones) by the conventional methods known per se and easily transposable by those skilled in the art to the present process.
• the invention is not limited to the embodiment described and shown in the accompanying drawings. Modifications remain possible, in particular from the point of view of the constitution of the various elements or by substitution of technical equivalents, without thereby departing from the scope of protection of the invention.

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• Engineering & Computer Science (AREA)
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• General Physics & Mathematics (AREA)
• Manufacturing & Machinery (AREA)
• Chemical & Material Sciences (AREA)
• Microelectronics & Electronic Packaging (AREA)
• Condensed Matter Physics & Semiconductors (AREA)
• Organic Chemistry (AREA)
• Computer Hardware Design (AREA)
• Power Engineering (AREA)
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• Metallurgy (AREA)
• Materials For Photolithography (AREA)

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• 2004
  • 2004-04-08 EP EP04742463A patent/EP1735663A1/de not_active Withdrawn
  • 2004-04-08 US US11/547,774 patent/US20070210393A1/en not_active Abandoned
  • 2004-04-08 WO PCT/FR2004/000876 patent/WO2005109097A1/fr active Application Filing

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