Classifications

• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P76/00—Manufacture or treatment of masks on semiconductor bodies, e.g. by lithography or photolithography
  • H10P76/40—Manufacture or treatment of masks on semiconductor bodies, e.g. by lithography or photolithography of masks comprising inorganic materials
  • H10P76/408—Manufacture or treatment of masks on semiconductor bodies, e.g. by lithography or photolithography of masks comprising inorganic materials characterised by their sizes, orientations, dispositions, behaviours or shapes
  • H10P76/4085—Manufacture or treatment of masks on semiconductor bodies, e.g. by lithography or photolithography of masks comprising inorganic materials characterised by their sizes, orientations, dispositions, behaviours or shapes characterised by the processes involved to create the masks
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10P—GENERIC PROCESSES OR APPARATUS FOR THE MANUFACTURE OR TREATMENT OF DEVICES COVERED BY CLASS H10
  • H10P50/00—Etching of wafers, substrates or parts of devices
  • H10P50/73—Etching of wafers, substrates or parts of devices using masks for insulating materials
• • H—ELECTRICITY
  • H10—SEMICONDUCTOR DEVICES; ELECTRIC SOLID-STATE DEVICES NOT OTHERWISE PROVIDED FOR
  • H10W—GENERIC PACKAGES, INTERCONNECTIONS, CONNECTORS OR OTHER CONSTRUCTIONAL DETAILS OF DEVICES COVERED BY CLASS H10
  • H10W20/00—Interconnections in chips, wafers or substrates
  • H10W20/01—Manufacture or treatment
  • H10W20/071—Manufacture or treatment of dielectric parts thereof
  • H10W20/081—Manufacture or treatment of dielectric parts thereof by forming openings in the dielectric parts
  • H10W20/089—Manufacture or treatment of dielectric parts thereof by forming openings in the dielectric parts using processes for implementing desired shapes or dispositions of the openings, e.g. double patterning

Definitions

• the present invention relates to the production of very dense patterns on a substrate comprising the use of block copolymers, and advantageously relates to a method of producing electrical conductors.
• the length of a transistor gate has increased from 25 nanometers in 2007 to 14 nanometers in 2012.
• the networks of conductors made on the printed circuits must be more and more dense.
• a sensitive layer deposited on the substrate is exposed with an ultraviolet beam through a mask defining patterns.
• the size of the smallest feasible pattern is closely related to the wavelength of the beam used: the shorter the wavelength, the finer the pattern can be and the greater the integration density can be.
• the ultraviolet beams used in photolithography have a wavelength of 193 or 248 nanometers.
• This type of lithography has the advantage of being very well controlled and inexpensive.
• very fine and dense patterns can be made on a substrate using a very narrow diameter electron beam. Nevertheless, since the definition of the patterns is carried out point by point, and not globally as in photolithography, the definition of patterns is much longer. On the other hand, when the width of the beam is used to define the width of the pattern, the problems of scattering and backscattering of electrons interfere with the control of the final dimension of the printed patterns.
• block copolymers in lithography is currently the subject of many studies. Indeed, this type of structure has the advantage of self-organizing generally into cylinders, spheres or lamellae with a very good resolution at the nanoscale. By covering a substrate with a layer of block copolymers and selectively removing one of the polymers, it is therefore possible to create fine patterns with high density.
• One way of using block copolymers and in particular chemopitaxis is to force the organization of the copolymer blocks by modifying the chemical properties of portions of the substrate.
• the substrate then comprises at the surface zones having a different affinity with a constituents of the copolymer which imposes the organization of the different blocks of the copolymer. This technique can be used for the purpose of improving the resolution of the domains formed by each type of polymer.
• This network makes it possible to guide the formation of the polymer blocks after they have been deposited, in order to improve the resolution of the pattern they create by self-organizing.
• the block copolymer layer is then insolated and etched to remove one of two types of polymer to create cavities.
• a layer of chromium is evaporated on the sample to create the network of conductors, then the hard mask is removed by the lift-off technique. This process step also eliminates portions of the chromium layer that are not desired.
• the sample is subjected to a dioxygen plasma to remove all organic traces.
• block copolymers in lithography
• SPIE Vol 8323 Another example of the use of block copolymers in lithography is "Contact Hole Patterning for Random Logic Circuits using Block Copolymer Directed Self-Assembly" (SPIE Vol 8323).
• SPIE Vol 8323 a conventional lithography is carried out initially.
• the network of first patterns formed using this lithography is then used as a guide for structuring a layer of block copolymers.
• the patterns are designed so that cavities formed using block copolymers correspond to the design chosen for the integrated circuit.
• the object of the invention is to remedy the aforementioned drawbacks by implementing a method of manufacturing patterns in first material comprising the following steps:
• first mask by means of a self-organized structure of block copolymers, the first mask defining a first series of first patterns organized according to a first repetition step
• the second mask comprising a second series of patterns organized according to the first repetition step or an integer multiple of first step of repetition, the second series having fewer motives than the first series,
• the intermediate mask is advantageously formed by electronic lithography, by means of a beam whose resolution is at least twice as large as the width of the first patterns that one seeks to discover. This criterion makes it possible to reopen each first hole as a whole.
• the use of a direct writing tool by electron multibeam is particularly recommended to achieve this step of the process, for the sake of speed of execution.
• the array of first pads can advantageously be formed in such a way that at least two of its guidelines form an angle of 45 °. This is particularly advantageous when two levels of metals to be connected have an identical pitch, as it is forbidden for two lines of metal of a higher level to be connected to the same metal line of a lower level.
• the array of first pads is made by modifying the chemical affinity of portions of the crystalline substrate.
• the network of first pads can be created by photolithography.
• the first holes are formed by grapho- epitaxy and photolithography.
• FIGS. 1 to 14 schematically illustrate one embodiment of the method
• FIG. 15 schematically shows the type of substrate on which a network of conductors is printed according to one embodiment of the invention
• a substrate 1 is provided and it is covered by a cover layer 2 and a layer of block copolymers 3 comprising at least first 3a and second 3b polymers.
• the block copolymer layer 3 forms a self-organized structure of block copolymers.
• the formed structure may be an alternation of rows of first and second polymers. It is also possible to form cylindrical first polymer patterns which are embedded within the second polymer. In general, depending on the polymer used and its conditions of use, it is possible to obtain a self-organization in lamellae, cylinders, spheres or other forms.
• the use of a layer of block copolymers 3 makes it possible to simply form a repeating pattern whose dimensions and shape are known to advance. Moreover, the use of block copolymers makes it possible to form patterns of small dimensions and with a repetition pitch which may be small. The dimensions of the pattern and / or the repetition pitch of these patterns may be below or of the same order of magnitude as the technical capabilities of the lithography processes. As a result, since the deposition of the copolymer layer 3 and the organization of the various polymers inside the layer is rapid, it is particularly advantageous to use this repetitive patterning technique in place of a photolithography technique more expensive and / or less fast. The use of a copolymer layer also makes it possible to form patterns with better resolution, better dimensional uniformity and with reduced line roughness.
• the copolymer layer 3 does not intrinsically have patterns of good dimensions and / or with a suitable pitch of repetition, it is possible to force the copolymer layer 3 to adapt the dimensions of its patterns and / or its steps. of repetition.
• a network of first projecting pads 4 is present or formed on the surface of the substrate 1, for example on the cover layer 2.
• the layer of block copolymers 3 is deposited on the cover layer 2, and disposed between the first studs 4 projecting. Between two successive first pads 4, the copolymer layer 3 is reorganized so as to present repeating patterns with a repetition pitch Pi which is compatible with the distance imposed between two first pads 4.
• the network of first pads 4 serves as a guide for the self-organization of the layer of block copolymers 3.
• a layer of block copolymers composed of two types of macromolecules are deposited for example by spin-coating.
• copolymer diblocks, copolymer triblocks, copolymer multiblocks, etc. could also be used.
• the surface of the substrate 1 has zones having different affinities with the block copolymer layer 3, so as to form a network of first pads 4.
• the difference chemical affinity acts in the same way as the mechanical stress of the pads 4 and imposes the position of one of the polymers of the copolymer layer 3.
• the cover layer 2 is flat and is formed of two materials different in surface on any layer intended to receive the layer of copolymers.
• the copolymer layer 3 has an alternation of repeating units with dimensions and / or a pitch pitch Pi defined by the length of the polymer chain and to a lesser extent by the distance between two successive pads 4 having particular affinity with one of the polymers.
• the copolymer layer 3 does not exhibit self-organization of the polymers to form a repeating pattern pattern. It may be necessary to perform thermal annealing in order to obtain the self-organization of the patterns.
• the pads 4 may form a repeating pattern, for example lines spaced with a repeat pitch greater than that of the future patterns defined in the copolymer layer 3. It is also conceivable to have some pads 4 having a repetition and others pads that are used to protect the substrate 1 and that escape a logic of repetition.
• an additional placement mask is made on the substrate 1.
• This additional placement mask can be formed by photolithography techniques at the desired resolution, for example with wavelengths at 193 nm or 248 nm. , that is to say at low resolution.
• lateral spacers covering the side walls of the additional mask are formed.
• the lateral spacers are manufactured by any suitable technique, for example a conformal deposition of spacer material followed by anisotropic etching.
• the copolymer may form an alternation of first and second units, for example two substantially identical patterns in the form, for example lines (two first polymer units are separated by a second polymer unit and vice versa). It is also possible to form a plurality of first polymer units which are embedded in a matrix formed by a second polymer.
• the layer of copolymer 3 textured by means of the various patterns 6 forms a first mask 5.
• the first mask 5 is formed from the copolymer layer 3, it has a first series of identical or substantially identical patterns 6 and with a first no substantially constant repeat Pi in all areas covered by the layer 3.
• such a mask is not practical to use because it is limited to a single density of patterns.
• the first patterns 6 (eg, holes) have a first single-direction repeat pitch that is parallel to the surface of the substrate 1.
• the first patterns 6 present first no repetition ⁇ and ⁇ in a first direction and a second direction. The two directions are secant and are parallel to the surface of the substrate 1. The repetition steps may be different in both directions or the same.
• a second mask 7 is made from the first mask 5.
• the second mask 7 takes up part of the patterns 6 of the first mask 5.
• the patterns of the second mask 7 have the same position as the patterns of the first mask 5, but part of the patterns 6 is not used.
• the second mask 7 defines a second series of patterns which is smaller in number than the first series of patterns 6 of the first mask 5. Since the second series of patterns is defined by taking part of the first series of patterns 6, the patterns of the second series retain the same spatial coherence as that defined by the self - organization of the copolymer layer 3. the second series are separated, in the repetition direction, by the repetition step or by an integer multiple of the repetition step.
• the second mask 7 It is possible to form, in the second mask 7, several distinct sets of patterns which all come from the same first mask 5.
• two distinct sets of patterns are separated by a distance greater than twice the pitch Pi of repetition and that is devoid of pattern 6.
• the coherent network of patterns 6 formed in the first mask 5 is kept between the different sets of patterns defined inside the second mask 7.
• the second mask 7 corresponds to the intersection between the first mask 5 and an intermediate mask 8. Only the patterns common to the first mask 5 and the intermediate mask 8 are used.
• part of the first mask 5 is subjected to electron radiation or electromagnetic radiation so as to modify the material of the copolymer layer forming the patterns 6. In this way, a part of the patterns is eliminated. and the other part is kept.
• This partial modification of the first mask 5 makes it possible to directly form the intermediate mask 8 in the first mask 5 and thus to form the second mask 7.
• the second mask 7 comprises a second series of patterns which have been chosen from the first series of patterns 6 .
• the second mask 7 has fewer patterns than the first mask 5.
• the patterns come from the first mask 5 and therefore they have between them a separation distance which is equal to the repetition pitch of the first mask 5 or which is an integer multiple of the repetition pitch of the first mask 5.
• the copolymer layer 3 is etched to texturize the second mask 7 and define the patterns of the second mask 7 with covered areas and open areas.
• At least one of the polymers of the self-organized copolymer layer 3 is removed so as to define the conserved patterns, i.e., first holes 6 or protruding patterns.
• the first mask 5 defined by the copolymer layer 3 is etched to define all the patterns 6 above the cover layer 2 with open areas and covered areas. As illustrated in FIG. 4, the copolymer layer 3 is etched so as to eliminate one of the copolymers.
• a network of patterns which is a network of holes or a network of projecting patterns. It is also possible to form a network with alternating holes and protruding patterns.
• the selective removal of one of the polymers from the copolymer layer 3 may be carried out by any suitable technique, for example by means of an etching agent which reacts only with one of the polymers, for example a solvent. It is also possible to subject the copolymer layer 3 to electromagnetic radiation which will harden one of the constituents and thus to facilitate the conditions of elimination of the other constituent. It is also conceivable to degrade or weaken one of the constituents of the copolymer layer 3 by means of electromagnetic radiation.
• the copolymer layer 3 is quite thick and if a difference in etching rate exists between the various constituents of the copolymer layer 3, it is possible to subject the copolymer layer 3 to ionic etching.
• the first mask 5 is formed as soon as one of the constituents has disappeared.
• first mask 5 has a plurality of first holes 6 which are spaced apart from one another according to the repetition step P r which initially existed in the copolymer layer 3.
• a dry etching using a hydrogen bromide plasma (HBr) is made to modify the structure of the copolymer and prevent the copolymer from being degraded by the solvent of the resins deposited in the posterior stages.
• the dry etching is not used and those skilled in the art will look for a resin having a solvent compatible with the material forming the first mask 5.
• the first mask 5 is formed by the polymer 3b which remains after removal of the polymer 3a from the copolymer layer 3.
• the pattern formed by the copolymer layer 3 is reproduced in an intermediate layer disposed between the copolymer layer 3 and the cover layer 2 to form the first mask 5.
• the first holes 6 of the first mask 5 are defined, it is possible to etch the other polymer material 3b of the copolymer layer 3, which makes it possible to slightly increase the dimensions of the first holes 6. This increase in the dimensions of the first holes 6 with respect to what was initially defined in the copolymer layer 3 while retaining the repeat pitch Pi.
• the preferred forms of the first holes may be cylindrical or lamellar.
• the first mask 5 forms an alternation of empty lines and lines of polymeric material. In other configurations, the first mask 5 forms a network of holes in a layer of polymeric material. In a configuration that is the opposite of the previous configuration, the first mask 5 forms an array of projecting patterns.
• a resin layer 9 is then deposited so as to cover the substrate 1 and the first mask 5 (see FIG.
• the resin layer 9 is subjected to an electronic or electromagnetic radiation so as to form an intermediate mask 8 on the first mask 5.
• the intermediate mask 8 defines second patterns 10, as shown in FIG. 6.
• the second patterns 10 are defined from a photolithography step, there is greater freedom in the definition of the patterns and therefore in the shape and dimensions of the second patterns as well as in their spacings.
• the second patterns 10 may be spaced apart with a second pitch P 2 which is greater than the first pitch Pi of the first patterns 6. It is also possible that the intermediate mask 8 does not have a second pitch of repetition P 2 .
• the intermediate mask 8 thus makes it possible to modulate the repetition pitch P 2 according to the needs of the user. For example, it is possible to produce an intermediate mask 8 having repetition steps ⁇ 2 ⁇ and ⁇ 2 ⁇ in a first direction and a second direction.
• the second mask 7 may comprise a second series of patterns 11 whose repetition pitch is equal to twice the repetition pitch Pi.
• the second series of patterns 11 can be broken down into groups of several first patterns 6 according to the first pitch Pi, the groups repeating themselves according to an integer multiple of the first pitch P ⁇ here five times the first step of repetition ⁇ ⁇ .
• the second series of patterns comprises at least three groups of several first patterns.
• the holes of the intermediate mask 8 face the first holes 6 of the first mask 5, which makes it possible to reach the cover layer 2 on the substrate 1.
• the second Mask 7 is formed by patterns 11 (here holes) having the minimum dimensions of the first mask 5 because the holes correspond to the dimensions of the copolymer patterns.
• the second mask 7 comprises zones without holes which make it possible to protect the cover 2, which is not possible with the first mask 5. It is therefore possible to have, in the second mask 7, important surfaces where the cover layer 2 is protected and areas inside which the Cover layer 2 may be etched by means of fine patterns (holes or protruding areas) and with a density which may be equal to that of the first mask 5.
• first mask 5 with a high density of first patterns 6, that is to say that the first patterns 6 have reduced dimensions and they are very close to each other.
• the intermediate mask 8 it is possible to modulate the density of the patterns 1 1 finally present in the second mask 7 without modifying the dimensions of the first patterns 6 defined in the first mask 5.
• the lithography method used to define the intermediate mask 8 has a minimum repeat pitch P2 equal to twice the no repetition of the first Pi units in the block copolymers (P 2 ⁇ 2.Pi). In this way, a first pattern 6 of two is covered by the intermediate mask 8 and the second mask 7 can reveal half of the first patterns 6 where necessary.
• the maximum flexibility for the second mask 7 is obtained when the intermediate mask 8 is made with a lithographic step which has a minimum distance between two successive patterns which is twice the repetition pitch of the first patterns 6.
• the first mask 5 makes it possible to define an array of first patterns 6 having small dimensions and with a very small pitch pitch Pi, but it is not possible to define inside the first mask 5 different organizations patterns 6.
• the intermediate mask 8 formed on the first mask 5 can modulate the drawing of the first mask 5 by defining coverage areas where the first patterns 6 are covered. By means of this intermediate mask 8, it is possible to retain the advantages of the first mask 5 while reducing the disadvantages of such a structure.
• the second mask 7 can have a great flexibility in its density of patterns 1 1, since the high density of the first mask 5 to the complete coverage of the areas to be protected.
• the intermediate mask 8 is produced by means of an electronic lithography because this makes it possible to have a small separation distance between two successive patterns.
• the copolymer layer 3 is configured so as to present first patterns 6 having a dimension less than or equal to that achievable by electronic lithography. If the first pitch pitch Pi is small, it is advantageous to form the intermediate mask 8 with the electronic lithography. In this way, the imperfections of the electronic shot noise stage are strongly erased by the first patterns 6 already formed in the first mask 5.
• the width of the electron beam used is chosen to be at least twice as large as the width of the first holes to be plugged or uncovered according to the polarity of the resin used.
• the axis of revolution of the electron beam does not perfectly match the axis of revolution of the first pattern 6 (if the latter is cylindrical), the latter can still be discovered or reseal as a whole.
• the cover layer 2 and possibly the substrate 1 are etched so as to present a drawing 11 equivalent or substantially equivalent to that present in the second mask 7 (see FIGS. .
• the second mask 7 is eliminated (see Figs 9 and 12), that is to say the first mask 5 and the intermediate mask 8, before or after deposition of a first material 13.
• the first material 13 is advantageously deposited in the holes 12 formed in the cover layer 2 to create patterns of the first material 13.
• the patterns of the first material 13 have dimensions substantially equal to those defined in the second mask 7 and their density. repetition is equal to that defined in the second mask 7.
• This method of defining holes of small sizes and with a large variation in the density of the holes is particularly advantageous for the production of electrical conductors in an integrated circuit.
• the substrate 1 is for example of the type shown in Figure 12. It is a crystalline semiconductor substrate 1 which already comprises several transistors 101 or other active or passive devices previously formed. The different devices are formed on the substrate 1 and are arranged with different arrangements.
• a transistor 101 it is necessary to define a contact for the source electrode 102, for the drain electrode 103 and for the gate electrode 104. It may be necessary to define a contact for the polarization of the substrate.
• the gates 104 of the transistors 101 are spaced by a repetition pitch ⁇ , it is necessary to define a repetition pitch less than or equal to that of the transistors 101 to define the contacts of the transistors.
• the different transistors are connected together and to other devices to form functionalities of an integrated circuit. The connections of the transistors are made by metal lines and metal contacts.
• the transistors 101 are covered by the cover layer 2, which is for example an electrically insulating layer, and the gates of the transistors 104 are flush to define a network of pads which will impose the position of the first holes 6 used by following to form contacts on the source electrodes 102, and drain 103.
• the transistors 101 are completely covered by the cover layer 2 and pads will be formed to force the copolymer layer 3 to present a first pitch pitch Pi compatible with that of the transistors 101 and / or with that of their electrodes. It may be the same to form metal contacts in the interconnection levels above the transistors 101.
• the cover layer 2 is electrically insulating and is covered by a second layer 2b of an anti-reflective material ("ARC" in English for Anti Reflective Coating) which is deposited above the polysilicon layer forming here the gate electrode.
• This layer 2b absorbs the waves reflected at the interface between the substrate 1 and the layer 2 which is immediately deposited on its surface to avoid parasitic reflections when defining the patterns in the subsequent lithography steps.
• a conventional photolithography is carried out to define pads 4.
• a layer of resin for example photoresist 9 is deposited.
• the resin layer 9 through a mask, with an ultraviolet source having a wavelength equal to 193 or 248 nanometers.
• This lithography step is performed with a definition less important than the step of defining the dimensions of the gate electrodes 104.
• the first pads 4 are formed on the insulating electrical layer 2 in order to force the copolymer layer 3 to present patterns having an orientation and / or dimensions and / or a first repetition pitch compatible with the definition of electrical conductors.
• the pads 4 separate areas of the substrate for which it is possible to isolate a repetition step.
• the first pitch Pi is smaller than the smallest dimension (length or width) defining an electrode or, more generally, a zone to be connected.
• the first mask 5 is configured to place a single hole facing the gate electrode along an axis which connects the source electrode to the drain electrode through the gate electrode. In this way, in the direction of the length of the gate, there are not several adjacent holes that open onto the gate electrode.
• the layer 3 of block copolymers is then deposited and self-organized using chemi-epitaxy or grapho-epitaxy.
• the first holes 6 are formed to define the first mask 5.
• the transistors 101 or other devices are aligned in a first direction so as to have a repetition pitch ⁇ , it is advantageous to force the copolymer layer 3 to present patterns and thus future first holes 6 in a secant second direction in the first direction.
• the pads 4 forcing the orientation of the copolymer units are configured so that the direction of repetition of the patterns forms an angle of 45 ° with the repetition direction of the transistors.
• the lateral faces of the studs 4 which define the direction of alignment of the patterns, for example a direction orthogonal to the lateral face of the pattern (see FIG. 14).
• each of the interconnection levels has metal having longitudinal axes oriented either in a first orientation or in a second orientation perpendicular to the first orientation.
• the offset of the direction of repetition of the first holes by an angle of 45 ° with respect to these two perpendicular orientations makes it possible to facilitate the connections of the different lines by preventing two lines facing each other from being short-circuited.
• the offset at 45 ° makes it easier to choose the area where the contact is sought and thus define the area where the first holes must be closed.
• the intermediate mask 8 is then formed on the first mask 5 to define the second mask 7.
• the intermediate mask 8 covers the areas where a metal contact is not sought. It also defines the density of metal contacts to be formed to ensure the connection while avoiding a short circuit.
• the intermediate mask 8 covers the first holes 6 which can overlap the gate electrode 104 and one of the source electrodes 102 and drain 03.
• the first mask 5 can define holes 6 according to a lamellar or cylindrical organization so as to define lines or vias.
• two levels containing lines oriented along two perpendicular directions Ox and Oy are separated by a level containing cylindrical contacts having a repetition pitch P in a direction offset at 45 ° from the directions Ox and Oy.
• the cover layer 2 is etched through the second mask 7 and a metallic material 13 is deposited in the holes 12 of the cover layer. cover 2 to form metal contacts, for example by evaporation of a metal.
• the polymer 3b surrounding each first hole 6 is not very sensitive to the electrons of the beam. This can for example be achieved by depositing a layer of resin 9 much thicker than the height of the first holes 6 to open.

Landscapes

• Exposure Of Semiconductors, Excluding Electron Or Ion Beam Exposure (AREA)
• Drying Of Semiconductors (AREA)
• Lead Frames For Integrated Circuits (AREA)

Applications Claiming Priority (2)

Publications (1)

Family

ID=49322404

Family Applications (1)

Country Status (4)

Families Citing this family (2)

Citations (1)

Family Cites Families (8)

• 2013
  • 2013-01-18 FR FR1300113A patent/FR3001306A1/fr active Pending
• 2014
  • 2014-01-17 EP EP14704379.8A patent/EP2946401A2/de not_active Withdrawn
  • 2014-01-17 US US14/760,382 patent/US9564328B2/en not_active Expired - Fee Related
  • 2014-01-17 WO PCT/FR2014/000010 patent/WO2014111637A2/fr not_active Ceased

Patent Citations (1)

Also Published As

Similar Documents

Legal Events