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
  • G03F7/0002—Lithographic processes using patterning methods other than those involving the exposure to radiation, e.g. by stamping
• • 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
• • 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
  • G03F7/16—Coating processes; Apparatus therefor
  • G03F7/168—Finishing the coated layer, e.g. drying, baking, soaking
• • 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
  • G03F7/20—Exposure; Apparatus therefor
  • G03F7/2002—Exposure; Apparatus therefor with visible light or UV light, through an original having an opaque pattern on a transparent support, e.g. film printing, projection printing; by reflection of visible or UV light from an original such as a printed image

Definitions

• the present invention relates to the field of surface energy control at each interface of a block copolymer film, to control the generation of patterns and their orientation at the time of nano-structuring said block copolymer .
• the invention relates to a method for controlling the surface energy of a block copolymer at its upper interface, in contact with a compound, or mixture of compounds, liquid, solid or gaseous.
• the invention furthermore relates to a method for manufacturing a nano-lithography mask from a block copolymer, said method comprising the steps of the method of controlling the surface energy at the upper interface of said block copolymer.
• the invention also relates to a surface neutralization top layer intended to cover the upper surface of the block copolymer.
• block copolymers it is possible to structure the arrangement of the constituent blocks of the copolymers, by phase segregation between the blocks thus forming nano-domains, at scales of less than 50 nm. Because of this ability to nanostructure, the use of block copolymers in the fields of electronics or optoelectronics is now well known.
• block copolymers intended to form nano-lithography masks must have nano-domains oriented perpendicularly to the surface of the substrate, so that they can subsequently be removed. selectively one block of the block copolymer and create a porous film with the (or) block (s) residual (s). The patterns thus created in the porous film can be subsequently transferred, by etching, to an underlying substrate.
• BCP block copolymer
• the interaction parameter between two blocks i and j of the block copolymer is therefore denoted x.
• the block copolymer is in contact with two interfaces: an interface called “lower” in the following description, in contact with the underlying substrate, and a so-called “upper” interface, in contact with another compound or mixture of compounds.
• the compound or mixture of compounds at the upper interface consists of ambient air or an atmosphere of controlled composition.
• the block copolymer unit may more generally be composed of any compound, or mixture of compounds, constitution and surface energy defined, whether solid, gaseous or liquid that is to say non-volatile at the temperature of self-organization of nano-domains.
• surface energy of each interface is not controlled, there is generally a random orientation of the block copolymer units, and more particularly an orientation parallel to the substrate, regardless of the morphology of the copolymer. to blocks.
• This parallel orientation is mainly due to the fact that the substrate and / or the compound (s) at the upper interface has a preferential affinity with one of the constituent blocks of the block copolymer at the temperature of self-organization said block copolymer.
• the Flory-Huggins type interaction parameter of a block i of the BCP block copolymer with the underlying substrate denoted Xi -SU bstrate, and / or the Flory-type interaction parameter.
• -Huggins of a block i of the BCP block copolymer with the compound at the upper interface, for example air denoted Xi -a ir, is different from zero and equivalently, the inter-facial energy Vi substrate and / or ⁇ -air is different from zero.
• FIG. 1 illustrates the case where the surface energy at the upper interface, between a block copolymer referenced BCP and the ambient air in the example, is not controlled, whereas the lower interface between the underlying substrate and the BCP block copolymer is neutral with a Flory-Huggins parameter for each of blocks i ... j of the block copolymer Xi -SU bstrat and Xj -S ubstrat equal to zero or, more generally , equivalent for each block of the BCP block copolymer.
• a layer of one of the blocks i or j of the block copolymer BCP, having the highest affinity with air, is organized in the upper part of the film of the BCP block copolymer, that is to say say at the interface with the air, and is paralleling this interface.
• the desired structure that is to say the generation of domains perpendicular to the surface of the substrate, whose patterns may be cylindrical, lamellar, helical or spherical, for example, requires a control of the energies of surface not only at the lower interface, ie at the interface with the underlying substrate, but also at the upper interface.
• the upper interface between the BCP block copolymer and the underlying substrate is today controlled, via the grafting of a random copolymer, for example, the upper interface between the block copolymer and a compound, or mixture of compounds, gaseous, solid or liquid, such as the atmosphere for example, is significantly less.
• a first solution could be to anneal the BCP block copolymer in the presence of a gaseous mixture to satisfy the conditions of neutrality with respect to each block of the block copolymer PCBs.
• a gaseous mixture to satisfy the conditions of neutrality with respect to each block of the block copolymer PCBs.
• the composition of such a gas mixture seems very complex to find.
• a second solution when the mixture of compounds at the upper interface consists of ambient air, consists in using a BCP block copolymer whose constituent blocks all have identical surface energy (or very close). one against the others, at the temperature of self-organization.
• the perpendicular organization of the nano-domains of the BCP block copolymer is obtained on the one hand, thanks to the BCP / substrate S copolymer interface neutralized by means of a a random copolymer N grafted to the surface of the substrate for example, and secondly, thanks to the fact that the blocks i of the block copolymer BCP naturally have a comparable affinity for the component at the upper interface, the air in the example.
• the surface energy of a given material depends on the temperature.
• the temperature of self-organization for example when we want to organize a block copolymer of large mass or large period, then requiring a lot of energy to obtain a correct organization, it is possible that the difference in surface energy of the blocks then becomes too great for the affinity of each of the blocks of the block copolymer for the compound at the upper interface can still be considered equivalent.
• the increase in the self-organization temperature can then cause the appearance of defects related to the non-perpendicularity of the assembly, due to the difference in surface energy between the blocks of the copolymer to blocks at the self-organizing temperature.
• a final solution envisaged consists in controlling the surface energy at the upper interface of a nano-structuring block copolymer of poly (trimethylsilystyrene-b-lactide) or poly (styrene-b-trimethylsilystyrene-b-styrene) type. by the introduction of an upper layer, also called “top coat” throughout the remainder of the description, deposited on the surface of the block copolymer.
• the top coat is deposited by "spin coating" on the nano-structuring block copolymer film.
• the top coat is soluble in an acidic or basic aqueous solution, which allows its application to the upper surface of the block copolymer, which is insoluble in water.
• the top coat is soluble in an aqueous solution of ammonium hydroxide.
• the top coat is a random or alternating copolymer whose composition comprises maleic anhydride. In solution, the ring opening of maleic anhydride allows the top coat to lose ammonia.
• the cycle of the maleic anhydride of the top coat closes, the top coat undergoes a transformation in a less polar state and becomes neutral with respect to the copolymer. blocks, thus allowing a perpendicular orientation of the nano-domains with respect to the two lower and upper interfaces.
• the top coat is then removed by washing in an acidic or basic solution.
• This solution allows to replace the upper interface between the block copolymer to be organized and a compound or mixture of gaseous compounds, solid or liquid, such as air in the example, by a block copolymer interface - top coat, denoted "BCP-TC".
• the difficulty of this solution lies in the deposit of the top coat itself.
• the top coat may have equivalent surface energy for each of the different blocks of the PCB block copolymer to be nanostructured at the time of the heat treatment.
• the invention therefore aims to remedy at least one of the disadvantages of the prior art.
• the aim of the invention is in particular to propose a simple and industrially feasible alternative solution for controlling the surface energy at the upper interface of a block copolymer so as to allow, on the one hand, self-assembly of the blocks.
• block copolymer such that the generated patterns are oriented perpendicularly to the substrate and the upper interface and secondly, a significant reduction in defectivity, related to the non-perpendicularity of the patterns.
• the subject of the invention is a method for controlling the surface energy at the upper interface of a block copolymer, the lower interface of which is in contact with a previously neutralized surface of a substrate, for obtaining an orientation of the nano-domains of said block copolymer perpendicular to the two lower and upper interfaces, said method comprising covering the upper surface of said block copolymer with a surface neutralization top layer, and being characterized in that said upper surface neutralization layer is constituted by a second block copolymer.
• the blocks of the block copolymer may have a modulated surface energy with respect to one another so that at the self-organization temperature of the first block copolymer, at least one of the blocks of the second copolymer the block has a neutral surface energy with respect to all the blocks of the first block copolymer.
• the first block copolymer and the second block copolymer are mixed in a common solvent and are deposited simultaneously, in a single step, on the previously neutralized surface of the substrate,
• the two block copolymers are immiscible with one another
• the first nano-structuring block copolymer is deposited on the previously neutralized surface of said substrate, and then the second block copolymer is deposited on the first block copolymer (BCP1) to allow neutralization of its upper surface,
• a step subsequent to the deposition of the two block copolymers consists in thermally treating the stack obtained, comprising the substrate, a neutralization layer, the first block copolymer and the second block copolymer, so as to nano-structure at least one two block copolymers,
• the nano-structuring of the two block copolymers is carried out in a single heat treatment step at a single annealing temperature
• the time required for organizing the second block copolymer is less than or equal to that of the first block copolymer
• the nano-structuring of the two block copolymers is carried out in several successive stages of heat treatment, using different temperatures and / or annealing times, the second block copolymer being organized more rapidly, or at a lower temperature, that first,
• the second block copolymer is unstructured at the organization temperature of the first block copolymer and the surface energy of one block, or set of blocks, of the second block copolymer is modulated by another block, or together of blocks of the second block copolymer such that all the blocks of the second block copolymer have equivalent surface energy for each block of the first block copolymer.
• the invention further relates to a nano-lithography mask manufacturing process from a block copolymer, whose lower interface is in contact with a previously neutralized surface of an underlying substrate , said process comprising the steps of the method of controlling the surface energy at the upper interface of said block copolymer as described above, and being characterized in that after the nano-structuring of the first block copolymer, the second The block copolymer forming the upper neutralization layer and at least one of the patterns generated in said first block copolymer are removed to create a film for use as a mask.
• the removal step is carried out by dry etching or by rinsing the second block copolymer in a solvent or solvent mixture, in which the first block copolymer is at least partly insoluble,
• a stimulus is applied to all or part of the stack constituted by the substrate, the lower neutralization layer, the first block copolymer and the second block copolymer,
• the stimulus consists in exposing all or part of the stack to UV-visible radiation, an electron beam, or a liquid exhibiting acid-base or oxidation-reduction properties,
• the second block copolymer is removed by dissolution in a solvent or solvent mixture in which the first block copolymer is at least partially insoluble before and / or after exposure to the stimulus,
• At least one block of the first block copolymer is sensitive to the applied stimulus, so that it can be removed simultaneously with the second block copolymer.
• the invention finally relates to a surface neutralization upper layer intended to cover the upper surface of a block copolymer, whose lower interface is in contact with a previously neutralized surface of a substrate, to allow obtaining an orientation of the nano-domains of said block copolymer perpendicular to the lower and upper surfaces, said surface neutralization top layer being characterized in that it consists of a second block copolymer.
• the block copolymer comprises at least two blocks, or sets of blocks, which are different,
• block copolymer may be synthesized by any technique or combination of techniques known to those skilled in the art,
• each block of the block copolymer can consist of a set of comonomers, copolymerized together under a block, gradient, statistical, random, alternating, comb,
• the block copolymer comprises a first block, or set of blocks, whose surface energy is the lowest of all the constituent blocks of the two block copolymers, and a second block, or group of blocks, having a zero or equivalent affinity for each block of the first block copolymer,
• the block copolymer comprises m blocks, m being an integer> 2 and ⁇ 1 1, and preferably ⁇ 5,
• the morphology of the block copolymer is preferably lamellar, without excluding the other possible morphologies,
• the volume fraction of each block of the block copolymer varies from 5 to 95% relative to the volume of the block copolymer
• the first block, or set of blocks, whose energy is the lowest, has a volume fraction of between 50% and 70% relative to the volume of the second block copolymer
• the second block copolymer has an annealing temperature lower than or equal to that of the first block copolymer
• the molecular weight of the block copolymer varies between 1000 and 500000 g / mol
• each block of the block copolymer may comprise comonomers present in the backbone of the first block copolymer (BCP1),
• the first block, or set of blocks, whose energy is the weakest, is soluble in a solvent or mixture of solvents, so that it favors the solubilizing the block copolymer in said solvent / solvent mixture at the time of its removal,
• the upper neutralization layer is in contact with a compound, or mixture of compounds of defined constitution and surface energy, which can be solid, gaseous or liquid at the organization temperature of the first and second block copolymers .
• FIG. 1 already described, a diagram of a block copolymer before and after the annealing step necessary for its self-assembly, when the surface energy at the upper interface is not controlled,
• FIG. 2 already described, a diagram of a block copolymer before and after the annealing step necessary for its self-assembly, when all the blocks of the block copolymer have a comparable affinity with the compound at the interface top,
• FIG. 3 a diagram of a block copolymer before and after the annealing step necessary for its self-assembly, when the block copolymer is covered with a top surface neutralization layer according to the invention
• FIG. 4 a schematic of a block copolymer before and after the removal of the surface neutralization top layer of FIG.
• polymers is meant either a copolymer (of statistical type, gradient, alternating blocks), or a homopolymer.
• the term "monomer” as used refers to a molecule that can undergo polymerization.
• polymerization refers to the process of converting a monomer or a mixture of monomers into a polymer.
• copolymer is meant a polymer comprising several different monomer units.
• random copolymer is meant a copolymer in which the distribution of monomer units along the chain follows a statistical law, for example example of Bernoullien type (Markov zero order) or Markovien of the first or second order.
• the repeat units are randomly distributed along the chain, the polymers were formed by a Bernouilli process and are called random copolymers.
• the term random copolymer is often used, even when the statistical process that prevailed during the synthesis of the copolymer is not known.
• gradient copolymer is meant a copolymer in which the distribution of the monomer units varies progressively along the chains.
• alternating copolymer a copolymer comprising at least two monomeric entities which are distributed alternately along the chains.
• block copolymer is understood to mean a polymer comprising one or more uninterrupted sequences of each of the different polymeric species, the polymer blocks being chemically different from one another or from one another and being linked together. by a chemical bond (covalent, ionic, hydrogen bonding, or coordination). These polymer blocks are still referred to as polymer blocks. These blocks have a phase segregation parameter (Flory-Huggins interaction parameter) such that, if the degree of polymerization of each block is greater than a critical value, they are not miscible with each other and separate into nanoparticles. areas.
• phase segregation parameter Flory-Huggins interaction parameter
• miscibility refers to the ability of two or more compounds to mix completely to form a homogeneous phase.
• the miscibility of a mixture can be determined when the sum of the glass transition temperatures (Tg) of the mixture is less than the sum of the Tg of the compounds taken alone.
• lower interface of a block copolymer to be nanostructured, the interface in contact with an underlying substrate on which a film of said block copolymer is deposited. It will be noted that, throughout the rest of the description, this lower interface is neutralized by a technique known to the man of the such as the grafting of a random copolymer on the surface of the substrate prior to deposition of the block copolymer film, for example.
• upper interface or "upper surface” of a block copolymer to be nano-structured, the interface in contact with a compound, or mixture of compounds, constitution and surface energy defined, that it is solid, gaseous or liquid that is to say non-volatile at the temperature of self-organization of the nano-domains.
• this mixture of compounds is constituted by the ambient air, but the invention is not limited to this case.
• the compound at the upper interface is gaseous, it can also be a controlled atmosphere, when the compound is liquid, it can be a solvent or mixture of solvents in which the block copolymer is insoluble, when the compound is solid it may for example be another substrate such as a silicon substrate for example.
• the principle of the invention consists in covering the upper surface of a nano-structuring block copolymer, referenced BCP1 in the following, itself previously deposited on an underlying substrate S whose surface has been neutralized. by grafting a layer N of random copolymer, for example, with a top layer, hereinafter referred to as "top coat” and referenced TC, the composition of which makes it possible to control the surface energy at the upper interface of said copolymer with blocks BPC1.
• top coat layer TC then makes it possible to orient the patterns generated during the nano-structuring of the BCP1 block copolymer, whether these are of cylindrical, lamellar or other morphology, perpendicular to the surface of the substrate S underlying and on the upper surface.
• the top coat layer TC is advantageously constituted by a second block copolymer, referenced BCP2 thereafter.
• the second block copolymer BCP2 comprises at least two blocks, or sets of blocks, different.
• this second block copolymer BCP2 comprises, on the one hand, a block, or a set of blocks, referenced "s 2 ", whose surface energy is the lowest of all the constituent blocks. of the two block copolymers BPC1, BPC2 and on the other hand, a block, or a set of blocks, referenced “r 2 ", having zero affinity with all the blocks of the first block copolymer BPC1 to be nano-structured.
• set of blocks blocks having the same or similar surface energy.
• the underlying substrate S may be a solid of inorganic, organic or metallic nature.
• BCP1 With regard to the nano-structuring block copolymer film, denoted BCP1, it comprises "n" blocks, n being an integer greater than or equal to 2 and preferably less than 1 1 and, more preferably , less than 4.
• the BCP1 copolymer is more particularly defined by the following general formula:
• i 1 ai 1 -co-bi 1 -co-. ..- co-Zi 1 , with i 1 ⁇ ... ⁇ j 1 , in whole or in part.
• the volume fraction of each entity a, 1 ... z, 1 can range from 1 to 100% in each of blocks i 1 ... j 1 of the BCP1 block copolymer.
• the volume fraction of each of the blocks i 1 ... j 1 can range from 5 to 95% of the BCP1 block copolymer.
• the volume fraction is defined as the volume of an entity relative to that of a block, or the volume of a block relative to that of the block copolymer.
• the volume fraction of each entity of a block of a copolymer, or of each block of a block copolymer, is measured in the manner described hereinafter.
• a copolymer in which at least one of the entities, or one of the blocks in the case of a block copolymer, comprises several comonomers it is possible to measure, by means of proton, the mole fraction of each monomer throughout the copolymer, and then back to the mass fraction using the molar mass of each monomer unit.
• each entity of a block, or each block of a copolymer it is then sufficient to add the mass fractions of the comonomers constituting the entity or the block.
• the volume fraction of each entity or block can then be determined from the mass fraction of each entity or block and the density of the polymer forming the entity or block.
• the density of polymers whose monomers are co-polymerized it is not always possible to obtain the density of polymers whose monomers are co-polymerized.
• the volume fraction of an entity or a block is determined from its mass fraction and the density of the bulk majority of the entity or block.
• the molecular weight of the BCP1 block copolymer may range from 1000 to 500000 g.mol -1 .
• the BCP1 block copolymer can have any type of architecture: linear, star (tri- or multi-arm), grafted, dendritic, comb.
• BCP2 constituting the upper neutralization layer, also called top coat and referenced TC, it is more particularly defined by the following general formula:
• a 2 -b- 2 -bC 2 -...- bZ 2 wherein A 2 , B 2 , C 2 , D 2 ,..., Z 2 , are all blocks "i 2 " ... " 2 "representing either pure chemical entities, that is to say that each block is a set of monomers of identical chemical natures, polymerized together, or a set of co-monomers copolymerized together, in form, in whole or in part , block copolymer or statistical or random or gradient or alternating.
• Each block "i 2 " .. "j 2 " of the block copolymer BCP 2 may consist of any number of comonomers, of any chemical nature, optionally including comonomers present in the skeleton of the first BCP1 block copolymer to be nano-structured, on all or part of the BCP2 block copolymer constituting the top coat.
• Each block “i 2 " .. “j 2 " of the BCP2 block copolymer comprising comonomers may be indifferently co-polymerized in the form of block copolymer or random or random or alternating or gradient on all or part of the blocks of the BCP2 block copolymer. In the order of preference, it is co-polymerized in the form of a random copolymer, or a gradient or random or alternating copolymer.
• j 2 " of the block copolymer BCP 2 may be different from each other, either by the nature of the comonomers present in each block, or by their number, or the same two by two as long as there are at least two blocks, or sets of blocks, different in the BCP2 block copolymer.
• one of the blocks, or set of blocks, denoted "s 2 " of the block copolymer BPC2 constituting the top coat has the lowest surface energy of all the blocks of the two block copolymers BPC1 and BPC2.
• the block "s 2 " of the second block copolymer blocks BPC2 comes into contact with the compound at the upper interface and is then parallel to the upper surface of the stack of layers consisting of the substrate S, the neutralization layer N, the block copolymer film BPC1 nanoparticles structure and the BPC2 block copolymer forming the TC top coat.
• the compound at the upper interface is constituted by a gas, and more particularly by ambient air.
• the gas can also be a controlled atmosphere for example.
• the difference in surface energy of this block "s 2 " with the other blocks of the two copolymers must therefore have a value sufficient to allow the block "s 2 " to end up at the upper interface.
• the second BCP2 block copolymer is already assembled or that it can be self-organized at the same time. annealing temperature, but with faster kinetics.
• the annealing temperature at which the second block copolymer self-organizes is therefore preferably less than or equal to the annealing temperature of the first block copolymer BPC1.
• the block "s 2 " which has the lowest surface energy of all the blocks of block copolymers BPC1, BPC2 is also the one which has the largest volume fraction of the block copolymer BPC2.
• its volume fraction can range from 50 to 70% relative to the total volume of the BPC2 block copolymer.
• the block “r 2 " then allows to neutralize and control the upper interface of the first block copolymer BPC1, and therefore contributes , with the block “s 2 ", the orientation of the nano-domains of the copolymer BPC1 perpendicularly to the lower and upper surfaces of the stack.
• the "r 2 " block can be defined according to any method known to those skilled in the art to obtain a "neutral" material for a given BPC1 block copolymer, for example a copolymerization in statistical form of the comonomers constituting the first copolymer BPC1 blocks according to a precise composition.
• the BPC2 block copolymer constituting the top coat is self-assembled, and the "s 2 " block finds itself oriented parallel to the interface with the ambient air and the "r 2 " block is found oriented in parallel. at the interface with the blocks of the BPC1 block copolymer film, thus permitting perpendicular organization of the BPC1 block copolymer patterns.
• the BCP2 block copolymer consists of "m" blocks, m being an integer> 2 and preferably less than or equal to 1 1 and, more preferably, less than or equal to 5.
• the period of the self-organized patterns of BCP2, noted L02, may have any value. Typically, it is located between 5 and 100nm.
• Morphology adopted by BCP2 block copolymer can also be any, ie lamellar, cylindrical, spherical, or more exotic. Preferably, it is lamellar.
• the volume fraction of each block may vary from 5 to 95% relative to the volume of the BCP2 block copolymer.
• at least one block will have a volume fraction ranging from 50 to 70% of the volume of the BCP2 block copolymer.
• this block representing the largest volume fraction of the copolymer is constituted by the block, or set of blocks, "s2".
• the molecular weight of BCP 2 can vary from 1000 to 500 000 g / mol. Its molecular dispersity can be between 1, 01 and 3.
• the BPC2 block copolymer may be synthesized by any appropriate polymerization technique, or combination of polymerization techniques, known to those skilled in the art, such as, for example, anionic polymerization, cationic polymerization, controlled radical polymerization or no, ring opening polymerization.
• the one or more constituent comonomers of each block will be selected from the usual list of monomers corresponding to the chosen polymerization technique.
• any controlled radical polymerization technique may be used, whether NMP ("Nitroxide Mediated Polymerization"), RAFT ("Reversible Addition and Fragmentation Transfer”).
• ATRP Atom Transfer Radical Polymerization
• INIFERTER Initiator-Transfer-Termination
• RITP Reverse lodine Transfer Polymerization
• ITP Long-Termine Transfer Polymerization
• nitroxides derived from alkoxyamines derived from the stable free radical (1) are preferred.
• the radical RL has a molar mass greater than 15.0342 g / mol.
• the radical RL can be a halogen atom such as chlorine, bromine or iodine, a linear, branched or cyclic hydrocarbon group, saturated or unsaturated such as an alkyl or phenyl radical, or a COOR ester group or a an alkoxyl group OR, or a phosphonate group PO (OR) 2, provided that it has a molar mass greater than 15.0342.
• the radical RL, monovalent, is said in position ⁇ with respect to the nitrogen atom of the nitroxide radical.
• the remaining valences of the carbon atom and the nitrogen atom in the formula (1) can be linked to various radicals such as a hydrogen atom, a hydrocarbon radical such as an alkyl, aryl or aryl radical. -alkyl, comprising from 1 to 10 carbon atoms. It is not excluded that the carbon atom and the nitrogen atom in the formula (1) are connected to each other via a divalent radical, so as to form a ring. Preferably, however, the remaining valencies of the carbon atom and the nitrogen atom of the formula (1) are attached to monovalent radicals.
• the radical RL has a molar mass greater than 30 g / mol.
• the RL radical may for example have a molar mass of between 40 and 450 g / mol.
• the radical RL may be a radical comprising a phosphoryl group, said radical RL being able to be represented by the formula:
• R3 and R4 which may be the same or different, may be selected from alkyl, cycloalkyl, alkoxyl, aryloxyl, aryl, aralkyloxy, perfluoroalkyl, aralkyl, and may include from 1 to 20 carbon atoms.
• R3 and / or R4 may also be a halogen atom such as a chlorine or bromine atom or a fluorine or iodine atom.
• the radical RL may also comprise at least one aromatic ring, such as for the phenyl radical or the naphthyl radical, the latter being able to be substituted, for example by an alkyl radical comprising from 1 to 4 carbon atoms.
• alkoxyamines derived from the following stable radicals are preferred: N-tert-butyl-1-phenyl-2-methylpropyl nitroxide,
• the alkoxyamines derived from N-tert-butyl-1-diethylphosphono-2,2-dimethylpropyl nitroxide will be used.
• the constituent comonomers of the polymers synthesized by a radical route will be chosen from the following monomers: vinylic, vinylidene, diene, olefinic, allylic or (meth) acrylic or cyclic monomers. These monomers are chosen more particularly from vinylaromatic monomers such as styrene or substituted styrenes, especially alpha-methylstyrene, acrylic monomers such as acrylic acid or its salts, alkyl acrylates, cycloalkyl acrylates or aryl acrylates.
• hydroxyalkyl acrylates such as 2-hydroxyethyl acrylate
• ether alkyl acrylates such as acrylate methoxyethyl, alkoxy- or aryloxy-polyalkylene glycol acrylates such as methoxypolyethylene glycol acrylates, ethoxypolyethylene glycol acrylates, methoxypolypropylene glycol acrylates, methoxy-polyethylene glycol-polypropylene glycol acrylates or mixtures thereof
• aminoalkyl acrylates such as 2- (dimethylamino) ethyl acrylate (ADAME), fluorinated acrylates, silyl acrylates, phosphorus acrylates such as pho acrylates alkylene glycol esters of glycidyl acrylates, dicyclopentenyloxyethyl acrylates, methacrylic
• any anionic polymerization mechanism may be considered, whether it is liganded anionic polymerization or anionic ring opening polymerization.
• an anionic polymerization process in an apolar solvent, and preferably toluene, as described in Patent EP0749987, and involving a micro-mixer is preferable.
• the constituent comonomer (s) of the polymers for example, will be chosen from the following monomers: vinyl, vinylidene, diene, olefinic and allylic monomers, (meth) acrylic or cyclic.
• These monomers are chosen more particularly from vinylaromatic monomers such as styrene or substituted styrenes, especially alpha-methylstyrene, silylated styrenes, acrylic monomers such as alkyl acrylates, cycloalkyl acrylates or aryl acrylates such as methyl, ethyl, butyl, ethylhexyl or phenyl, ether alkyl acrylates such as 2-methoxyethyl acrylate, alkoxy- or aryloxy-polyalkyleneglycol acrylates such as methoxypolyethylene glycol acrylates, acrylates ethoxypolyethylene glycol acrylates, methoxypolypropylene glycol acrylates, methoxy-polyethylene glycol-polypropylene glycol acrylates or mixtures thereof, aminoalkyl acrylates such as 2- (dimethylamino) ethyl acrylate (ADAME),
• the second BCP2 block copolymer forming the TC top coat layer can be deposited on the copolymer film.
• BCP1 block itself previously deposited on an underlying substrate S whose surface has been neutralized N by any means known to those skilled in the art, or it can be deposited simultaneously with the first BCP1 block copolymer.
• the two block copolymers BCP1 and BCP2 are deposited successively or simultaneously, they can be deposited on the surface of the substrate S previously neutralized N, according to techniques known to those skilled in the art, such as for example the so-called technique “ spin coating ",” Doctor Blade “” knife System “or” slot die System “.
• the two block copolymers BCP1 and BCP2 have a common solvent, so that they can be deposited on the underlying substrate S, the surface of which has been previously neutralized, in a single and same step.
• the two copolymers are solubilized in the common solvent and form a mixture of any proportions.
• the proportions can by For example, they can be chosen according to the desired thickness of the BCP1 block copolymer film intended to serve as a nano-lithography mask.
• the two copolymers BCP1 and BCP2 must not be miscible with one another, or at least very little miscible, in order to prevent the second BCP2 copolymer from disturbing the morphology adopted by the first BCP1 block copolymer.
• the mixture of BCP1 + BCP2 block copolymers can then be deposited on the surface of the substrate, according to techniques known to those skilled in the art, such as for example the technique known as "spin coating", “doctor blade” “knife” System “or” slot die System ".
• a stack of layers is thus obtained comprising the substrate S, a neutralization layer N, the first block copolymer BCP1 and the second block copolymer BCP2.
• the BPC2 block copolymer forming the TC top coat layer exhibits the well known phenomenon of phase separation block copolymers at an annealing temperature.
• the stack obtained is then subjected to a heat treatment so as to nano-structure at least one of the two block copolymers.
• the second BCP2 block copolymer nano-structure first so that its lower interface can have a neutrality vis-à-vis the first BCP1 copolymer at the time of its self-organization.
• the annealing temperature of the second block copolymer BCP2 is preferably less than or equal to the annealing temperature of the first block copolymer BCP1 while being greater than the highest glass transition temperature of BCP1.
• the time required for the organization of the second BCP2 block copolymer is preferably less than or equal to that of the first block copolymer.
• the first block copolymer BPC1 self-organizes and generates patterns, while the second block copolymer BPC2 is also structured. so as to have at least two distinct domains "s 2 " and "r 2 ".
• Such a copolymer is symmetrical when the volume fractions of each block constituting the copolymer BPC2 are equivalent, in the absence of particular interactions or specific frustration phenomena between different blocks of the BPC2 block copolymer, leading to a distortion of the phase diagram. relating to the BPC2 copolymer. More generally, x S 2-r2.Nt should be greater than a curve describing the phase separation limit, named "MST" (of the acronym "Microphase Separation Transition”) between an ordered system and a disordered system. , dependent on the intrinsic composition of the BCP2 block copolymer. This condition is for example described by L.
• the BPC2 block copolymer does not exhibit structuring at the assembly temperature of the first BPC1 block copolymer.
• the surface energy of the block "r 2 " is modulated by the presence of the block "s 2 ", and it must be readjusted so as to have an equivalent surface energy with respect to all the blocks of the first BCP1 block copolymer.
• the block “s 2 " serves in this case only solubilizing group for the block copolymer BPC2. It should be noted, however, that the surface energy of the blocks of the BCP2 block copolymer strongly depends on the temperature. Preferably, the time required for the organization of the BCP2 block copolymer forming the top coat is less than or equal to that of the first BCP1 block copolymer.
• the "s 2 " block of the BPC2 block copolymer constitutive of the TC top coat may be highly soluble in a solvent, or mixture of solvents, which is not a solvent or solvent mixture of the first copolymer.
• BPC1 intended to be nano-structured to form a nano-lithography mask.
• the "s 2 " block can then act as an agent promoting the solubilization of the BPC2 block copolymer in this particular solvent or solvent mixture, denoted "MS2", which then allows the subsequent removal of the second BCP2 block copolymer.
• the method of manufacturing a nano-lithography mask when the BCP1 block copolymer film is nano-structured and its patterns are oriented perpendicularly to the surface of the stack, it is necessary to proceed to the removal of the upper layer of top coat TC formed by the second block copolymer BCP2, in order to be able to use the nano-structured BCP1 block copolymer film as a mask in a nano-lithography process, to transfer its patterns in the underlying substrate.
• the removal of the block copolymer BPC2 may be carried out either by rinsing with a solvent, or solvent mixture MS2, non-solvent, at least in part, for the first BCP1 block copolymer, or by dry etching, such as the plasma etching, for example, in which the gas chemistry (s) used is adapted according to the intrinsic constituents of the BCP2 block copolymer.
• a nano-structured BCP1 block copolymer film is obtained, whose nano-domains are oriented perpendicularly to the surface of the underlying substrate, as shown in the diagram of FIG. FIG. 4.
• This block copolymer film is then able to serve as a mask, after removal of at least one of its blocks to leave a porous film and thus be able to transfer its patterns in the underlying substrate by a nanoparticles process. lithography.
• a stimulus may also be applied to all or part of the stack obtained, consisting of the substrate S, the N layer. surface neutralization of the substrate, the BCP1 block copolymer film and the BCP2 block copolymer top layer.
• a stimulus can for example be achieved by exposure to UV-visible radiation, a beam electron, or a liquid with acid-base properties or oxidation-reduction for example.
• the stimulus then makes it possible to induce a chemical modification on all or part of the block copolymer BCP2 of the upper layer, by cleavage of polymer chains, formation of ionic species, etc. Such a modification then facilitates the dissolution of the block copolymer.
• This solvent or mixture of solvents MS3 may be identical to or different from the solvent MS2, depending on the importance of the solubility modification of the BPC2 block copolymer following exposure to the stimulus.
• the first block copolymer BCP1 at least in part, that is to say at least one block constituting it, may be sensitive to the stimulus applied, so that the block in question can to be modified following the stimulus, following the same principle as the modified BCP2 block copolymer thanks to the stimulus.
• at least one block of the BPC1 block copolymer can also be removed so that a film for use as a mask is obtained.
• the BCP1 mask copolymer is a block copolymer of PS-b-PMMA
• a stimulus by exposing the stack to UV radiation will cleave the PMMA polymer chains.
• the PMMA units of the first block copolymer can be removed, simultaneously with the second block copolymer BCP2, by dissolving in a solvent or solvent mixture MS2, MS3.
• the BPC1 block copolymer intended to serve as a nano-lithography mask is of lamellar morphology and constituted by a diblock system of PS-b-PMMA type

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• 2015
  • 2015-06-02 FR FR1554982A patent/FR3037070B1/fr not_active Expired - Fee Related
• 2016
  • 2016-05-26 JP JP2017562680A patent/JP2018524154A/ja active Pending
  • 2016-05-26 CN CN201680039637.9A patent/CN107735727A/zh active Pending
  • 2016-05-26 KR KR1020177035413A patent/KR20180005223A/ko not_active Application Discontinuation
  • 2016-05-26 WO PCT/FR2016/051252 patent/WO2016193582A1/fr active Application Filing
  • 2016-05-26 US US15/579,063 patent/US20180173094A1/en not_active Abandoned
  • 2016-05-26 SG SG11201709937SA patent/SG11201709937SA/en unknown
  • 2016-05-26 EP EP16730881.6A patent/EP3304198A1/de not_active Withdrawn
  • 2016-05-27 TW TW105116664A patent/TW201715296A/zh unknown

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